Eau douce

392(6798) - 07 May 2026 - Big fish: how villagers and scientists protected a freshwater giant - and its Amazon ecosystem (Bulletin de Science)

Mon, 8 Jun 2026 16:21:34

Sommaire : News In Depth - Deep-Earth map points to a lost U.S. continent Sensor array traces how rocks conduct electricity, revealing mineral riches, crust that can amplify solar storms, and fragments of ancient landmasses - After pulling vaccine study, CDC leader calls for new journal Jay Bhattacharya clashes with epidemiologists over widely used design - Arrest of Fauci aide for records violations decried as political David Morens’s indictment centers on help he gave nonprofit that funded China research blamed for pandemic - Chaotic whale rescue shocks marine biologists Timmy, a humpback stranded in Germany 6 weeks ago, was freed after a media outcry. But the whale was in poor health and may already be dead - AI scientist agents violate research integrity rules Advanced AI systems are shown to make up data and “p-hack” their results - Magic mushroom compound shows promise against cocaine addiction Small study that prioritized Black and low-income participants yields “remarkable” results - How ‘spikes’ in the epileptic brain are harmful—and might be tamed Abnormal electrical bursts hijack neurons involved in cognition and can be predicted up to 1 second in advance, new study finds Feature - The power of a fish In the remote reaches of the Amazon, scientists are working with villages to protect an ecosystem while boosting the economy Commentary Perspectives - Forecasting volcanic eruptions across scales Predicting future volcanic eruptions requires better understanding of crustal magma storage - Delivering a STING to tumors STING agonist nanoparticles trigger potent antitumor immunity in mice and rabbits - The future of plant extinction Analyses of large-scale datasets call for urgent action to conserve plant diversity - Building an oral peptide drug Engineered enzymes enable kilogram-scale synthesis of drug for high-cholesterol conditions Letters - Conflict imperils Middle East marine life - The vulnerability of Middle East desalination - Safeguard water infrastructure amid conflict Policy Articles - Aging and the narrowing of scientific innovation Aging researchers and the removal of retirement policies yield decreased disruptive innovation in science Research Articles - Short RNA chaperones promote aggregation-resistant TDP-43 conformers to mitigate neurodegeneration - Human DHX29 detects nonoptimal codon usage to regulate mRNA stability - Intermetallic nanoassemblies potentiate systemic STING activation - Tuft dendrites in frontal motor cortex enable flexible learning - Rapid directed evolution guided by protein language models and epistatic interactions - A molecule with half-Möbius topology - Competitive reactivity drives size- and composition-focusing in multimetallic nanocrystals - Ferrimagnetism of ultracold fermions in a multiband Hubbard system - Dynamic segmentation of the Sagaing fault - Realization of a spin glass in a two-dimensional van der Waals material - Wildfire damages and the cost-effective role of forest fuel treatments - Alkylidene functionalization produces highly recyclable and scalable polyhydroxyalkanoates - Biocatalytic cascades enable manufacture of the macrocyclic peptide enlicitide - Climate-induced range shifts support local plant diversity but don’t reduce extinction risk - High risk of extinction across the flowering plant tree of life

Apparent Hack's law in river deltas

Fri, 22 May 2026 14:39:59

River deltas are densely populated, ecologically vital landscapes threatened by rising sea levels. Distributary channel networks disperse sediment to build deltaic land, yet the relationship between the network organization and land building remains elusive. Inspired by Hack’s law, which shows that watershed drainage area scales with channel length in tributary networks, we analyzed a global dataset of distributary networks and found a nearly identical scaling relationship between distributary channel length and nourishment area, the land-building counterpart to drainage area. Despite this apparent global scaling, we further identified two distinct local land-building patterns: uniform delta networks consistently follow Hack’s law, whereas composite delta networks exhibit a scale break, transitioning from space-filling growth around the delta apex to quasi-linear growth near the coast. The unexpected growth patterns suggest that global simplicity and local variability coexist in how river deltas grow and organize.

Exposure to a mixture of organic pollutants in a threatened freshwater turtle Emys orbicularis: effects of age, sex, and temporal variation

Wed, 11 Mar 2026 16:05:55

Freshwater ecosystems constitute major sinks for organic contaminants, increasing anthropogenic pressures and threatening the unique biodiversity they harbour. In addition to persistent legacy compounds, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), various pollutants are less persistent but are chronically released, including polycyclic aromatic hydrocarbons (PAHs), phthalate diesters (PAEs), pyrethroid pesticides, and insect repellent. Heretofore, these pollutants have received insufficient attention in freshwater reptiles, considering their potential to trigger detrimental effects on organisms. During two years (2019 and 2020), we quantified plasma levels of 46 compounds from 7 chemical families in two monitored populations of the protected European pond turtle (Emys orbicularis) in the Camargue wetland, France. PAHs and PAEs were found predominantly and concomitantly, with similar occurrences and levels in the two populations. We observed similar inter-annual variations in PAHs and PAEs with differences between males and females, highlighting the need for a better assessment of the role of sex in the exposure pathway and the toxicokinetics of contaminants, especially in turtles. The negative relationship between PAH levels and age, as well as the high intra-individual variation in levels of both contaminant families, provides further evidence of limited bioaccumulation of these pollutants in the blood of E. orbicularis. This could be explained by the metabolic biotransformation of parent compounds, highlighting the need to quantify the levels of PAH metabolites and phthalate monoesters. Finally, our work underscores the importance of long-term monitoring to better determine the vulnerability of turtle populations already exposed to a wide range of contaminants.

CISTOX – Les reptiles exposés aux produits phytopharmaceutiques : intégration des effets chez une tortue d’eau douce protégée à l’échelle nationale (2026)

Mon, 31 Aug 2026 16:43:21

Nous avons pu échantillonner un nombre important de populations (15) en 2 ans de suivis (311 individus). Le projet CISTOX a permis des mises au point méthodologiques pour les dosages des contaminants, du stress oxydatif et des comptages des cellules sanguines, pour lesquels les validations n’étaient pas disponibles auparavant pour les échantillons de Cistude d’Europe. Nous avons pu produire des résultats sur de nombreux marqueurs physiologiques, permettant d’avoir une vision intégrative des réponses à la pollution. Nous avons mis en évidence une corrélation claire entre la contamination en pesticides de l’eau, notamment par la bentazone, et la proportion d’individus contaminés dans les populations de Camargue. Nous soulignons ainsi le rôle majeur de la riziculture sur les risques d’exposition aux pesticides pour la Cistude d’Europe. Les réponses physiologiques semblent complexes chez cette espèce, mais nous avons pu observer une perturbation de l’immunité fonctionnelle, avec des variations de certaines lignées leucocytaires comme les basophiles. Enfin, des approches originales sont en cours pour tenter de comprendre les relations tripartites entre la contamination en éléments traces métalliques, l’immunité et le microbiome des cistudes. La valorisation scientifique a été au cœur de nos préoccupations avec trois articles publiés et plusieurs articles en soumission ou en cours de rédaction pour la fin 2026. La réalisation d’un documentaire est également prévue pour diffuser les travaux et communiquer sur le rôle de sentinelle des zones humides de la Cistude d’Europe. Nos travaux ont fait l'objet de nombreuses communications auprès de publics variés (colloques scientifiques, ANSES, grand public) et ont aussi servi de support pour les enseignements de Licence et de Master de l’Ecole Pratique des Hautes Etudes.

Modélisation intégrée des réseaux d’activités, des services écosystémiques, et de la biodiversité sur l’île de Camargue. Evaluation des impacts du changement climatique et de la transition agroécologique sur un delta (2026)

Wed, 8 Jul 2026 14:26:48

Les deltas constituent des socio-écosystèmes parmi les plus productifs et les plus peuplés au monde, mais aussi parmi les plus vulnérables aux changements globaux. Soumis simultanément aux pressions climatiques (élévation du niveau marin, salinisation des sols, modifications des régimes de précipitations...) et aux pressions anthropiques (changement de gestion de l’eau et de pratiques agricoles) ces territoires à l'interface continent-mer font face à des défis de gestion important. La Camargue, delta du Rhône, en est un cas d'étude emblématique. Ce delta est un système socio-écologique (SES) particulièrement complexe, caractérisé par une forte imbrication entre milieux naturels et activités humaines : riche en biodiversité, et avec des activités agricoles, de chasse, de pêche et touristiques majeures, ce territoire est aujourd'hui confronté à une salinisation croissante des sols, à des modifications profondes des régimes hydrologiques et à des transformations de ses pratiques agricoles. Dans ce contexte, comprendre et anticiper les dynamiques couplées entre gestion de l'eau, agriculture et écologie représente un enjeu scientifique et sociétal de premier plan, partagé par la grande majorité des deltas mondiaux. Cette thèse s'est structurée autour de deux questions de recherche : Comment modéliser les interactions entre dynamiques hydrosalines, agricoles et écologiques dans un delta soumis à des pressions multiples ? Et quels sont les effets des forçages anthropiques et climatiques sur ces dynamiques en Camargue ? Pour y répondre, nous avons d'abord développé un modèle conceptuel de l'île de Camargue, articulé autour de quatre sous-modèles portant respectivement sur la gouvernance de l'eau, l'agriculture, les communautés d'oiseaux et les communautés de poissons. Ce cadre conceptuel, mobilisant les outils de l'analyse des systèmes socio-écologiques, a permis de formaliser les chaînes causales, boucles de rétroaction, compromis et effets indirects structurant ce SES deltaïque. Sur cette base, nous avons développé MAELIA-Delta, un modèle intégré couplant dynamique hydrosaline et pratiques agricoles à l'échelle de l'île de Camargue, évalué à travers une situation de référence et plusieurs scénarios climatiques et agricoles contrastés. Les résultats obtenus apportent des connaissances nouvelles sur le fonctionnement de ce SES. Le cadre conceptuel formalise un réseau de 101 entités et 165 processus, au sein duquel cinq compromis structurants ont été identifiés (notamment entre quantité et qualité de l'eau, ou entre activités de pêche et agricole). Le modèle MAELIA-Delta reproduit les dynamiques hydrosalines caractéristiques de la Camargue : il simule notamment une salinité estivale nettement plus élevée dans les parcelles sèches (8,7 dS/m) que dans les parcelles irriguées par submersion (3,3 dS/m), et met en évidence des effets de transfert latéral d'eau entre parcelles voisines, vecteurs de remontées salines dans les zones non irriguées. À l'échelle de l'île de Camargue, les scénarios révèlent que les surfaces rizicoles constituent la variable de commande dominante du système hydrique : un scénario de diversification agroécologique, caractérisé par une réduction de 76 % des surfaces en riz, entraîne une diminution de 51 % des volumes d'irrigation, mais au prix d'une salinisation accrue et d'une diminution des rendements, tandis qu'un scénario d'intensification agricole accroît l'irrigation de 21 %, et de 26% les rejets de drainage agricole. Ces résultats soulignent l'existence de compromis fondamentaux entre ambitions agroécologiques, maîtrise de la salinisation et préservation des milieux naturels, et confirment le rôle pivot de la riziculture dans l'équilibre hydrique et écologique du delta. En conclusion, cette thèse apporte trois contributions scientifiques majeures : i) une formalisation inédite des interactions couplées eau-agriculture-biodiversité à l'échelle d'un delta méditerranéen, dépassant les 24 approches disciplinaires traditionnelles ; ii) un outil de simulation opérationnel et transférable à d'autres deltas soumis à des dynamiques similaires ; iii) des connaissances sur les effets des pratiques agricoles et du climat sur l'équilibre hydrique et écologique du delta, mobilisables par les gestionnaires et décideurs du territoire camarguais. À moyen terme, MAELIA-Delta constitue une base solide pour enrichir la représentation des interactions entre réseaux hydrauliques, milieux naturels et biodiversité, et pour étendre l'analyse à d'autres systèmes deltaïques confrontés aux défis des changements globaux.

Effects of the global change on the thermal habitat quality for Salmonids within the Upper Soča watershed in Slovenia

Wed, 29 Oct 2025 15:34:41

Temporal data series of water temperature collected at various locations in the Upper Soča river basin, a pristine area in Slovenia, from 1996 to 2022, were analyzed to assess any trends as potential effects of the global change. Different temperature metrics were calculated to study more especially eventual impacts on trout species known as present in the target sites: the endemic marble trout (Salmo marmoratus), the introduced common trout (Salmo trutta) and hybrid trout (S. marmoratus x S. trutta). Significant trends were observed in more than half of the streams considered, indicating a general warming of water temperatures across the entire Upper Soča basin. The high regional coherence found for streams in the three watersheds (Soča, Bača and Idrijca) studied suggested regional synchrony and an overall predominant climatic influence. However, a greater variation was observed in spring and summer, suggesting the implications of additional local factors. The majority of the monitored sites (n = 18 out of 25) experienced an increase in the annual mean temperature (+ 0.04 °C per year on average), especially in summer (+0.1 °C per year on average for 19 sites) when flows were lower. Thermal conditions remained favourable for salmonids in all sites. However, temperatures above 15 °C or even 19 °C are expected to be increasingly recorded, enhancing periods with stressful conditions for salmonids, at first for the endemic S. marmoratus.

Diversity of freshwater leeches (Annelida: Hirudinida) in the West Bank, Palestine

Fri, 28 Mar 2025 10:37:14

This study provides an overview of the leech fauna of West Bank, Palestine based on newly collected material from the West Bank and data from the literature. A total of 17 species belonging to four families and six genera are known. Among these species, three represent new records for Palestine (West Bank): Helobdella europaea, Erpobdella cylindrica, and Erpobdella testacea. A brief biogeographic examination of some species is presented at both regional and continental levels.

Domestic water buffaloes: an unexpected basking support for two sympatric freshwater turtles, Emys orbicularis (Linnaeus, 1758) and Mauremys rivulata (Valenciennes, 1833) in Türkiye

Fri, 5 Sep 2025 15:54:17

This study aims to present new data on the relationships between domestic water buffaloes and reptiles.

Life-history traits of the invasive and biggest European freshwater fish, the wels catfish (Silurus glanis) show high potential for colonisation in Southern Europe

Mon, 6 Jan 2025 15:32:51

The invasive wels catfish is spreading to many European waterbodies and is the subject of controversy concerning its environmental impact.The objective was to investigate its life-history traits (growth and reproduction) for the first time in southern France. A culling action was used to assess the key life-history traits, using sections of pectoral spines for age and growth estimations, and gonad macroscopic examination for the reproduction parameters. The biggest individual was a 227-cm male. The age was accurately estimated from clear translucent marks on spines, with a maximum of 13years for both sexes. The growth appeared to be extremely rapid and was the highest at old ages recorded from both the native and the invasive distribution range. The length and age at first sexual maturity, 70.1cm for 4–5-year-old females, and 54.1cm for 2–3-year-old males, were the lowest recorded in Europe, indicating an early maturity. The life-history parameters (rapid growth, early maturation, high fecundity) showed a very high potential for adaptation and colonisation. The cost and management required to regulate the species appear not easily feasible, particularly when combined with its high growth rate.

Ease and Limitations in Using Environmental DNA to Track the Spread of Invasive Host–Parasite Complexes: A Case Study of the Freshwater Fish Pseudorasbora parva and the Cryptic Fungal Parasite Sphaerothecum destruens

Wed, 27 Nov 2024 16:25:17

The spread of non-native species threatens biodiversity and exacerbates societal challenges like food security. To address this, effective conservation programs require detection methods that are easy to implement, accurate, and non-invasive. Over the past 15 years, environmental DNA (eDNA) techniques have gained popularity, surpassing traditional sampling methods. In this context, our study focused on tracking the invasive host–pathogen complex Pseudorasbora parva and Sphaerothecum destruens using eDNA metabarcoding. We collected water samples from freshwater canals over five months in the Camargue region, and once in Corsica Island, both in southern France. Total DNA was extracted from filtered water samples, and PCR-amplicons were sequenced using Illumina or Nanopore technologies. Our results revealed a high detection rate of P. parva in lentic ecosystems, aligning with habitat preferences of this small freshwater fish. Additionally, the detection rate in Camargue increased in May and June, likely due to the peak of the spawning season, which leads to more DNA being released into the environment (i.e., concentration and interaction of individuals). While eDNA successfully detected this invasive fish, we were unable to detect its cryptic fungal parasite, S. destruens, highlighting the challenges of identifying intracellular and cryptic fungal pathogens through eDNA methods.

Chemodiversity in freshwater health

Wed, 17 Apr 2024 16:01:16

A new species within the genus Bithynia (Gastropoda: Bithyniidae) from northwestern Türkiye

Wed, 17 Apr 2024 16:01:26

In Türkiye, the family Bithyniidae is represented by two genera: Bithynia (Leach, 1818) and Pseudobithynia (Glöer & Pešić, 2006). Recent studies have shown that Bithyniidae species have a broad distribution across southeastern Europe, including Greece, Montenegro, and Bulgaria. In Türkiye, a total of 14 species have been documented so far, with nine belonging to the genus Bithynia and five to Pseudobithynia. We found a new Bithynia species in Kocaçay Stream, situated in the southern Marmara Region. This newly identified species has been compared with all known congeners from nearby ecosystems in Türkiye and neighbouring countries. http://www.zoobank.org/urn:lsid:zoobank.org:pub:C9665C20-F606-4763-8C82-E0DCFB23C7D8

Freshwater parasites as potential barriers to seabird dispersal: Evidence from vagrant booby specimens in western North America

Wed, 21 Feb 2024 15:53:41

La errancia y dispersión en tierra adentro de las aves marinas son fenómenos raros cuyas causas y consecuencias se entienden poco. Estudiar registros en tierra adentro de aves marinas es importante ya que las masas continentales forman barreras a la dispersión de genes y parásitos; por lo tanto, la permeabilidad de las barreras terrestres influye en qué tanto las poblaciones de aves evolucionan en trayectorias distintas y co-evolucionan con faunas parásitas distintas. Los alcatraces (Sula spp.) constituyen un clado de especies obligadas de agua salada que se encuentran en oceános tropicales y subtropicales. Las especies de alcatraces tienden a exhibir estructura genética poblacional entre regiones oceánicas. Aunque raramente deambula en tierra firme, el alcatraz pardo (Sula leucogaster) se ha reportado muchas veces como errante en tierra adentro de Norteamérica. Previos reportes de tierra adentro en el lejano oeste Norteamericano se originaron de poblaciones del Pacífico (subespecies brewsteri), mientras que los del este y el medioeste de Norteamérica se originan de poblaciones del Caribe (subespecie leucogaster). En este artículo, describimos 2 especímenes nuevos de S. leucogaster, primeros registros estatales para Nuevo México y Colorado, procedentes de localidades casi equidistantes de poblaciones fuente de Pacífico y el Caribe. Utilizamos secuencias de ADN mitocondrial para mostrar conclusivamente que ambos especímenes se originaron en el Caribe. Luego, examinamos la fauna de helmintos parásitos de ambos especímenes de S. leucogaster y de un alcatraz de patas azules (S. nebouxii) que vagaba tierra adentro en Nuevo México. Los intestinos de estos alcatraces contenían una serie de helmintos, incluyendo varios taxa obligadas de agua dulce. Con base en nuestros hallazgos, sugerimos que la susceptibilidad a los parásitos de agua dulce puede ocasionar que la dispersión en tierra adentro no sea exitosa para los alcatraces u otras aves marinas. Por lo tanto, los parásitos de agua dulce pueden contribuir a explicar la relativa rareza de la dispersión transcontinental, el mantenimiento de la fuerte estructura genética inter-oceánica, la conservación filogenética de la especialización en hábitats de agua salada y la distribución estrictamente pelágica de especies oceánicas pertenecientes a varias familias de aves. Palabras clave: agua dulce, errancia, espécimen, helmintos, parásito, Sula.

Pesticide concentrations in a threatened freshwater turtle (Emys orbicularis): Seasonal and annual variation in the Camargue wetland, France

Tue, 21 Nov 2023 15:28:58

Wetlands are among the most threatened ecosystems on the planet and pollution is a major factor causing the decline of wetland biodiversity. Despite the increasing use of pesticides, their fate and effects on freshwater reptiles remain largely unknown. We studied the European pond turtle (Emys orbicularis), a long-lived species at risk with a high exposure potential to pesticides. Between 2018 and 2020, we measured 29 pesticides and metabolites in 408 blood samples of turtles from two populations in the Camargue wetland (France). We were able to quantify 24 compounds and at least one pesticide or one degradation product in 62.5% of samples. Pesticide occurrences and concentrations were low, except for a herbicide widely used in rice cultivation and locally detected in water: bentazone that reached high blood concentrations in E. orbicularis. The occurrence and the concentration of pesticides in E. orbicularis blood depended mainly on the site and the sampling date in relation to pesticide application. Individual characteristics (sex, age, body condition) did not explain the occurrence or the concentration of pesticides found in turtle blood. Assessing the exposure of aquatic wildlife to a cocktail of currently-used pesticides is a first and crucial step before studying their effects at the individual and population levels.

Direct and indirect estimates of dispersal support strong juvenile philopatry and male-biased dispersal in a freshwater turtle species (Emys orbicularis)

Fri, 22 Sep 2023 15:36:57

Dispersal has major impacts on population dynamics, population genetics and evolution, and also is critical for population management and conservation. Dispersal is frequently sex- and age-specific, but current knowledge is strongly taxonomically biased toward birds and mammals. Here, we provide estimates of dispersal in a threatened freshwater turtle species, the European pond turtle Emys orbicularis. Based on 15 years of capture-mark-recapture (CMR) monitoring and DNA samples from 194 individuals, we quantified both demographic and genetic dispersal between three sites separated by 1.5–3.5 km. We also investigated the effect of age and sex on dispersal. Direct (CMR) and indirect (genetic) approaches provided consistent results, showing that the studied sites are connected with a flow of about one to three dozen migrants per generation. Dispersal was both age- and sex-biased in this species, with frequent dispersal of adult males and a strong philopatry of juveniles (of both sexes) and adult females. The network of canals and marshes allow effective dispersal to occur among the three study sites despite the relatively large distance separating them (≤3.5 km). The strong philopatry of juveniles contrasts with the frequently higher dispersal rate in young birds and mammals and shows the relevance of investigating dispersal in various taxonomic groups. Our results provide useful information for the conservation of European pond turtle populations.

Ecosystem services, vulnerability and threat levels of Ramsar wetlands in the complex of Aurès Sbkhates, North-Eastern Algeria

Mon, 21 Aug 2023 15:21:51

A socio-economic study were carried out in the wetlands complex of Aurès Sebkhates, in North Eastern Algeria. This study aimed to identify the ecosystem services obtained by local stakeholders, describe the anthropogenic impacts and evaluate the vulnerability and threat levels of three Ramsar wetlands: Garaet Timerganine (freshwater), Garaet Annk Djemel & El Merhsel (brackish water) and Sebkhet Ezzmoul (salt water). A socio-economic survey was conducted of 70 randomly selected households (social group) and 24 people belonging to the local administration (focus group). Vulnerability and threat levels were analyzed. Provisioning and monetary value are the most relevant ecosystem services (water pumping, grazing, agriculture, area for recreation, plant and egg collection, salt mining). Indirect ecosystem services rendered by the studied wetlands (water treatment/flood control) are only known by the focus group. 95% of the surveyed locals believed that the studied wetlands have experienced significant degradation in recent years mainly by human activity. Our results revealed significant threats due to salt mining and the excessive water pumping practiced within the three sites. Natural stressors such as drying out, erosion and siltation also contribute to the disturbance of these wetlands.

Compositional breakpoints of freshwater plant communities across continents

Tue, 10 Oct 2023 10:00:42

Compositional breakpoints of freshwater plant communities across continents unravelling patterns and mechanisms of biogeographical transitions is crucial if we are to understand compositional gradients at large spatial extents, but no studies have thus far examined breakpoints in community composition of freshwater plants across continents. Using a dataset of almost 500 observations of lake plant community composition from six continents, we examined, for the first time, if such breakpoints in geographical space exist for freshwater plants and how well a suite of ecological factors (including climatic and local environmental variables) can explain transitions in community composition from the subtropics to the poles. Our combination of multivariate regression tree (MRT) analysis and k-means partitioning suggests that the most abrupt breakpoint exists between temperate to boreal regions on the one hand and freshwater plant communities harbouring mainly subtropical or Mediterranean assemblages on the other. The spatially structured variation in current climatic conditions is the most likely candidate for controlling these latitudinal patterns, although one cannot rule out joint effects of eco-evolutionary constraints in the harsher high-latitude environments and post-glacial migration lags after Pleistocene Ice Ages. Overall, our study supports the foundations of global regionalisation for freshwater plants and anticipates further biogeographical research on freshwater plant communities once datasets have been harmonised for conducting large-scale spatial analyses.

Documenting the impacts of increasing salinity in freshwater and coastal ecosystems: Introduction to the special issue

Fri, 24 Mar 2023 18:42:05

Dynamique temporelle de la biodiversité en cours d’eau

Fri, 3 Feb 2023 18:23:46

If there is no doubt that biodiversity declines at a global scale, surprisingly the literature on this topic raises contrasting conclusions about local biodiversity trends. We still have an incomplete understanding of how ecosystems evolve under global change. Here, we aimed to characterize the recent temporal dynamics of river biodiversity in France, from both a taxonomic and a functional point of view, concerning different key organisms (diatoms, macro-invertebrates and fish), with a large range of biodiversity metrics and over a multi-decade period. Our results on sensitive taxa recovery in all three groups provided strong evidence that water quality management in France over the past decades successfully decreased nutrient loads in streams. On the other hand, diatom and to a lesser extent fish richness declined over time, while macroinvertebrate taxonomic richness increased. Finally, the study revealed consistent rearrangements within stream communities, with a shift from planktonic to benthic primary production, resulting in functional changes in macro-invertebrate and fish trait composition.

Outils pour améliorer la mesure du débit minimum biologique des petits cours d'eau

Fri, 3 Feb 2023 18:23:46

In the French regulatory context, the sharing of water uses in rivers must ensure the maintenance of the ecological balance of rivers. In France, the French Office of Biodiversity (OFB) is in charge of most of the verification of the minimum required flow. INRAE has been involved for many years in supporting the OFB in this mission through trainings and the spreading of tools to facilitate and improve stream discharge measurement. This article presents two examples of recent achievements from the 2019-2021 OFB-INRAE agreement. The first example is the organisation of an interlaboratory comparison of discharge measurements using the tracer dilution method, the second is the development and dissemination of a model of transparent velocity head rod, a low-cost tool for measuring discharge.

Identification and Ecology of Freshwater Arthropods in the Mediterranean Basin (2023)

Mon, 6 Jan 2025 15:32:47

The book provides an extensive description of the taxonomy and ecology of aquatic arthropods encountered in lentic and lotic habitats, as well as in less studied underground and estuarine habitats. It offers expanded taxonomic identification keys to major groups of arthropods with a description of their ecology and distribution. Keys for insects include aquatic larval stages and water-dwelling adults of Coleoptera and Heteroptera. Additional sections focus on taxa that can be encountered in adjacent brackish and estuary ecosystems as long as the taxon primarily occurs in freshwaters. This is a much-needed, comprehensive resource on the taxonomy and ecology of freshwater arthropods with an introduction to recent molecular tools for identifications. It will be particularly useful for freshwater ecologists, limnologists, environmentalists and students in the ecological sciences.

Habitat use of spoonbills in man-made habitats in a freshwater area in The Netherlands (Extended abstract) (2023)

Tue, 24 Oct 2023 18:21:16

River ecosystem metabolism and carbon biogeochemistry in a changing world

Fri, 20 Jan 2023 16:13:37

River networks represent the largest biogeochemical nexus between the continents, ocean and atmosphere. Our current understanding of the role of rivers in the global carbon cycle remains limited, which makes it difficult to predict how global change may alter the timing and spatial distribution of riverine carbon sequestration and greenhouse gas emissions. Here we review the state of river ecosystem metabolism research and synthesize the current best available estimates of river ecosystem metabolism. We quantify the organic and inorganic carbon flux from land to global rivers and show that their net ecosystem production and carbon dioxide emissions shift the organic to inorganic carbon balance en route from land to the coastal ocean. Furthermore, we discuss how global change may affect river ecosystem metabolism and related carbon fluxes and identify research directions that can help to develop better predictions of the effects of global change on riverine ecosystem processes. We argue that a global river observing system will play a key role in understanding river networks and their future evolution in the context of the global carbon budget.

Conservation Status of the Hispaniolan Slider, Trachemys decorata, at Lake Trou Caïman, Eastern Haiti: First Data on an Endemic, Poorly Studied, and Endangered Species

Wed, 4 Jan 2023 11:14:29

The Hispaniolan Slider (Trachemys decorata) is a freshwater turtle of conservation interest, endemic to the island of Hispaniola. Although the species is known to be threatened with habitat destruction, hybridization with congeneric species, and commercial harvesting, little information is available on natural populations. Here we report the results of a pilot study conducted at Lake Trou Caïman, Haïti. From October 2017 to February 2018, we captured 44 individuals (mostly in areas dominated by cattails, Typhaceae) and had access to 48 additional individuals held in captivity by fishers and local people. Captive individuals were significantly larger than wildcaught ones. Based on individuals with a carapace length > 100 mm, sex-ratio did not differ from parity in either wild-caught or captive individuals. Females tended to be larger and heavier than males. The frequency of damaged carapace or plastron and/or wounds was significantly higher in captive individuals compared to individuals freshly captured in the lake, indicating poor husbandry. About 10% of all individuals showed orange supratemporal stripes, suggestive of hybridization with the Central Antillean Slider (T. stejnegeri) or the Red-eared Slider (T. scripta elegans). Based on interviews with 31 local fishers, we estimated that at least 1,600 T. decorata are harvested each year at Lake Trou Caïman. We discuss our results in relation to the conservation and management of T. decorata in Haiti

Combination of marine and artificial freshwater habitats provides wintering Black-tailed Godwits with landscape supplementation

Thu, 6 Oct 2022 10:32:22

Rewetting global wetlands effectively reduces major greenhouse gas emissions

Thu, 1 Sep 2022 16:20:51

Carbon and nitrogen losses from degraded wetlands and methane emissions from flooded wetlands are both important sources of greenhouse gas emissions. However, the net-exchange dependence on hydrothermal conditions and wetland integrity remains unclear. Using a global-scale in situ database on net greenhouse gas exchanges, we show diverse hydrology-influenced emission patterns in CO2, CH4 and N2O. We find that total CO2-equivalent emissions from wetlands are kept to a minimum when the water table is near the surface. By contrast, greenhouse gas exchange rates peak in flooded and drained conditions. By extrapolating the current trajectory of degradation, we estimate that between 2021 and 2100, wetlands could result in greenhouse gas emissions equivalent to around 408 gigatons of CO2. However, rewetting wetlands could reduce these emissions such that the radiative forcing caused by CH4 and N2O is fully compensated by CO2 uptake. As wetland greenhouse gas budgets are highly sensitive to changes in wetland area, the resulting impact on climate from wetlands will depend on the balance between future degradation and restoration. Global in situ observations show greenhouse gas emissions from wetlands are lowest when the water table is near the surface, and therefore rewetting wetlands could substantially reduce future emissions.

Restoring marble trout genes in the Soča River (Slovenia)

Mon, 27 Feb 2023 15:20:49

In Slovenia, the unique watershed naturally hosting the marble trout is the Soča River, called Isonzo in Italy. In 1993–1996 molecular data established the existence of extensive hybridization with stocked Atlantic domestic lineages which is a threat for this taxon and for the economy of the country established on the angling tourism. Different management actions have been developed for restoring marble genes since 1996: banning stocking of brown trout, revising fishing regulations for anglers and testing genetically brood stock in hatchery for stocking phenotypic and pure marble fry. This long fight against hybridization was genetically surveyed using allozymes, mitochondrial sequences and microsatellites according to the available technique at each period. Despite the irregularity of genotyping along nearly fifteen years after the new management started, it appears that the proportion of domestic lineage in the river dropped regularly of about 2% each year, a positive result for conservative management measures.

Securing the Environmental Water Requirements of Seasonally Ponding Wetlands: Partnering Science and Management through Benefit Sharing

Mon, 30 May 2022 17:49:01

Although environmental flow regime assessments are becoming increasingly holistic, they rarely provoke water managers to enact the adaptive water reallocation mechanisms required to secure environmental water for wetlands. The conditions that cause science-based environmental flow assessments to succeed or fail in informing the management of environmental water requirements remain unclear. To begin to resolve these conditions, we used process tracing to deconstruct the sequence of activities required to manage environmental water in four case studies of seasonally ponding wetlands in Mediterranean and Mesoamerican watersheds. We hypothesized that, when the flexibility and equitability of the socioeconomic system do not match the complexity of the biophysical system, this leads to a failure of managers to integrate scientific guidance in their allocation of environmental water. Diagnostic evidence gathered indicates that science-management partnerships are essential to align institutional flexibility and socioeconomic equitability with the system’s ecohydrological complexity, and thus move from determination to reallocation of environmental water. These results confirm that institutions e.g., river basin organizations need to be supplemented by motivated actors with experience and skill to negotiate allocation and adaptive management of environmental water. These institutional-actor synergies are likely to be especially important in water scarce regions when the need to accommodate extreme hydrological conditions is not met by national governance capacity. We conclude by focusing on benefit sharing as a means to better describe the conditions for successful science-based environmental flow assessments that realize productive efficiency in environmental water allocation i.e., recognition of multiple values for both people and ecosystems.

Spatial priorities for freshwater biodiversity conservation in light of catchment protection and connectivity in Europe

Tue, 13 Sep 2022 16:14:14

Freshwater ecosystems host disproportionately high numbers of species relative to their surface area yet are poorly protected globally. We used data on the distribution of 1631 species of aquatic plant, mollusc, odonate and fish in 18,816 river and lake catchments in Europe to establish spatial conservation priorities based on the occurrence of threatened, rangerestricted and endemic species using the Marxan systematic conservation planning tool. We found that priorities were highest for rivers and ancient lakes in S Europe, large rivers and lakes in E and N Europe, smaller lakes in NW Europe and karst/limestone areas in the Balkans, S France and central Europe. The a priori inclusion of well-protected catchments resulted in geographically more balanced priorities and better coverage of threatened (critically endangered, endangered and vulnerable) species. The a priori exclusion of well-protected catchments showed that priority areas that need further conservation interventions are in S and E Europe. We developed three ways to evaluate the correspondence between conservation priority and current protection by assessing whether a cathment has more (or less) priority given its protection level relative to all other catchments. Each method found that priority relative to protection was high in S and E Europe and generally low in NW Europe. The inclusion of hydrological connectivity had little influence on these patterns but decreased the coverage of threatened species, indicating a trade-off between connectivity and conservation of threatened species. Our results suggest that catchments in S and E Europe need urgent conservation attention (protected areas, restoration, management, species protection) in the face of imminent threats such as river regulation, dam construction, hydropower development and climate change. Our study presents continental-scale conservation priorities for freshwater ecosystems in ecologically meaningful planning units and will thus be important in freshwater biodiversity conservation policy and practice, and water management in Europe.

Ecosystem services provided by marine and freshwater phytoplankton

Wed, 15 Jun 2022 15:35:03

Phytoplankton, the ecological group of microalgae adapted to live in apparent suspension in water masses, is much more than an ecosystem’s engineer. In this opinion paper, we use our experience as phytoplankton ecologists to list and highlight the services provided by phytoplankton, trying to demonstrate how their activity is fundamental to regulate and sustain Life on our Planet. Although the number of services produced by phytoplankton can be considered less numerous than that produced by other photosynthetic organisms, the ubiquity of this group of organisms, and their thriving across oceanic ecosystems make it one of the biological engines moving our biosphere. Supporting services provided by phytoplankton include almost half of the global primary and oxygen production. In addition, phytoplankton greatly pushes biogeochemical cycles and nutrient (re)cycling, not only in aquatic ecosystems but also in terrestrial ones. In addition, it significantly contributes to climate regulation (regulating services), supplies food, fuels, active ingredients and drugs, and genetic resources (provisioning services), has inspired artistic and craft works, mythology, and, of course, science (cultural services), and much more. Therefore, phytoplankton should be considered in all respects a true biosphere’s engineer.

Biodiversity survey of the Drinos and Suhë river catchments (Albania) (2022)

Fri, 22 Sep 2023 15:37:35

The rivers of the Balkan region are one of the most important hotspots for European freshwater biodiversity. However, many hydropower plants (HPP) are projected to be built in the next few years, leaving few rivers untouched. Among the multitude of rivers currently threatened by dam projects in the Balkan region are the transboundary river Aoos/ Vjosa and its tributaries. Many hydropower plants are planned along this river system. Scientific knowledge about the biodiversity of the Aoos / Vjosa river system remains currently limited and it is especially the case of its tributaries. A biological baseline survey is being carried out, involving the contribution of many scientists, aimed at collecting data on the ecological aspects most relevant for the Environmental Impact Assessment.. In order to contribute to this initiative, two biologists from the Tour du Valat Research Institute for the Conservation of Mediterranean Wetlands (France) organized a rapid survey from 4-9 June 2022, targeting areas located along the Drinos and the Suhë rivers. The Drinos is the main tributary of the Vjosa and has its source in the northwestern tip of Greece. The Suhë is one of the main tributaries of the Drinos. This rapid survey focused on the inventory of birds, amphibians and reptiles, with additional data obtained on the occurrence of the Eurasian Otter (Lutra lutra). This short report presents the survey carried out and its main results.

The conservation status of freshwater species and habitats in Key Biodiversity Areas at the Sebou river basin (2022)

Mon, 18 Jul 2022 11:34:08

This report presents the results of a broad assessment of the freshwater diversity in four Key Biodiversity Areas (KBAs) and some key additional sites in the Sebou river basin in Morocco.

Classification écologique des zones humides du Maroc (2022)

Wed, 22 Jun 2022 09:46:05

Cet ouvrage présente une classiﬁcation des zones humides du Maroc, qui répond à un double objectif (1) connaitre les caractéristiques fonctionnelles et la diversité de ces écosystèmes et (2) servir de référentiel pour en établir une liste rouge. Les critères utilisés ont permis de hiérarchiser les types décrits dans un schéma à six niveaux, composé de 4 catégories, éclatée-s en 15 systèmes, subdivisés en 37 classes et 47 sous-classes, éventuellement en faciès et variantes. Cette hiérarchie a abouti à 110 types élémentaires d'écosystemes, répartis comme suit : eaux stagnantes (18), eaux courantes (20), sources (10), écosystèmes marins côtiers (16), lagunes et estuaires (13), habitats littoraux (7), eaux phréatiques (4), eaux artificielles (22). Concernant les nouveautés apportées par notre classiﬁcation, elles mettent principalement en exergue les particularités liées aux régimes pluviométriques saharien et méditerranéen, qui ont généré une grande variété d'écosystemes temporaires. De même, les crises récentes de sécheresse ont mis à sec de nombreux lacs et oueds considérés auparavant comme permanents et que nous avons distingués en types à part. Plusieurs autres types d'écosystemes nouvellement décrits ne sont pas forcément spéciﬁques aux climats arides ; c’est le cas des réservoirs de barrages naturels, dont la genèse et le fonctionnement permettent de les différencier des lacs endoréiques et d’y déﬁnir divers types, dispatches entre différents systèmes. Les facteurs hydrologiques et de genèse nous ont amené à des remaniements par rapport aux schémas de classiﬁcation existants ; lesquels remaniements ont concerné divers systèmes et classes : sebkhas/ chotts, sources, estuaires, habitats littoraux, salines, canaux artificiels, etc. Dans ce même contexte, les oasis ne sont pas considérées comme type d’écosystème naturel identifiable à l’aide d’un même critère, ce qui a amené à éliminer l’entité ’oasis’ et à dispatcher sur divers systèmes continentaux, tout en laissant la porte ouverte à leur classiﬁcation comme milieux très anthropisés.

Tumors (re)shape biotic interactions within ecosystems: Experimental evidence from the freshwater cnidarian Hydra

Mon, 6 Sep 2021 15:37:36

While it is often assumed that oncogenic processes in metazoans can inﬂuence species interactions, empirical evidence is lacking. Here, we use the cnidarian Hydra oligactis to experimentally explore the consequences of tumor associated phenotypic alterations for its predation ability, relationship with commensal ciliates and vulnerability to predators. Unexpectedly, hydra's predation ability was higher in tumorous polyps compared to non-tumorous ones. Commensal ciliates colonized preferentially tumorous hydras than non-tumorous ones, and had a higher replication rate on the former. Finally, in a choice experiment, tumorous hydras were preferentially eaten by a ﬁsh predator. This study, for the ﬁrst time, provides evidence that neoplastic growth has the potential, through effect(s) on host phenotype, to alter biotic interactions within ecosystems and should thus be taken into account by ecologists. /Bien que les processus oncogéniques à l’origine des cancers soient omniprésents chez les organismes multicellulaires, ils ont jusqu’à très récemment été largement ignorés par la communauté scientifique en écologie évolutive. Du fait de la relative lenteur des progressions tumorales, il est pourtant attendu que les maladies cancéreuses, avant d’être éventuellement mortelles pour leurs hôtes, modifient le phénotype de ces derniers et les amènent à interagir différemment avec les autres espèces de l’écosystème. Aucune étude expérimentale n’avait jusqu’à ce jour mis cette hypothèse à l’épreuve. Le cnidaire d’eau douce, Hydra oligactis (embranchement regroupant les méduses et les coraux), a été ici utilisé comme modèle pour explorer expérimentalement les conséquences écologiques des modifications phénotypiques associées aux tumeurs. De manière inattendue, les hydres tumorales sont capables de capturer plus de proies que les hydres saines, en raison d’un nombre supérieur de tentacules. Les ciliés commensaux vivant à leur surface colonisent préférentiellement les hydres tumorales, et ont un taux de réplication plus élevé sur ces dernières. Enfin, les hydres tumorales sont préférentiellement mangées par les poissons prédateurs. Cette étude apporte pour la première fois la démonstration que les développements tumoraux ont le potentiel, par leurs effets sur le phénotype de leurs hôtes, de modifier les interactions biotiques au sein des écosystèmes. Ce travail suggère ainsi que les processus cancéreux au sein de la faune sauvage, notamment dans les habitats pollués, devraient davantage être pris en compte par les écologistes.

Great Cormorants Phalacrocorax carbo in the Subalpine Soča River System, Slovenia: The Possible Effect of Avian Predators in a Sensitive Biogeographic Region for Fish

Mon, 19 Sep 2022 11:25:14

The Diet of Two Sympatric Great Cormorant Phalacrocorax carbo Subspecies Wintering at Freshwater Fishery Sites in England and Wales

Mon, 19 Sep 2022 11:25:00

The environmental framework of temporary ponds: A tropical-mediterranean comparison

Wed, 15 Dec 2021 16:21:23

Temporary ponds are distributed worldwide, providing significant ecological services. Their limnological features are influenced by a set of regional (mainly climate) and local (natural or anthropogenic) factors. To evaluate the differences in their ecological functioning in distant geographic regions, we analysed the main features of 90 temporary ponds located in three distinct areas: two mediterranean-climate regions (Eastern Iberian Peninsula and Central Chile) and a tropical setting in Costa Rica. Each pond was surveyed thrice during the hydrological cycle of 2017–2018, and five sets of parameters were obtained: limnological, hydrogeomorphological, biotic, landscape and climatic variables. Through multivariate analyses, we determined the environmental heterogeneity of each region and the main environmental differences among them. As expected, hydrogeomorphological factors did not differ between regions, but climate variables showed marked differences between the tropical and the two mediterranean regions. We also detected clear differences between mediterranean and tropical ponds in terms of their mineralization patterns (mainly conductivity and alkalinity), natural vegetation cover and land use. Despite the regional similarities between mediterranean regions, some strong differences were found concerning vegetation cover, nutrient concentration and trophic state, probably associated to human activities (agriculture and extensive stockbreeding).

Évaluer la qualité des boisements riverains avec l’Indice de Biodiversité et de Connectivité des Ripisylves (IBCR) : une étude de cas avec les communautés d’oiseaux

Mon, 25 Oct 2021 14:36:39

Afin d’évaluer la capacité d’accueil des ripisylves pour la biodiversité, nous proposons un nouvel indice tenant compte des dimensions longitudinale et transversale de l’hydrosystème : l’Indice de Biodiversité et de Connectivité des Ripisylves (IBCR). Constitué de 15 facteurs renseignant des critères liés au peuplement et à sa gestion, au contexte environnant, aux perturbations/pressions et à la connectivité, l’IBCR est un nouvel outil qui fournit aux gestionnaires des cours d’eau des éléments concrets pour diagnostiquer rapidement l’état écologique des ripisylves et orienter la gestion pour la conservation de la biodiversité associée aux linéaires boisés riverains. Pour illustrer l’utilité de cet indice, nous avons étudié la réponse des communautés d’oiseaux aux facteurs de l’IBCR, en distinguant les espèces des milieux forestiers, agricoles, aquatiques et bâtis/rocheux. Nos résultats montrent que les cortèges d’oiseaux répondent de façon assez cohérente aux valeurs de l’IBCR, avec une augmentation de la richesse en espèces d’oiseaux des milieux forestiers avec l’augmentation du score moyen de l’indice. En revanche, les ripisylves ayant un indice de faible score, c’est-à-dire davantage dégradées et déconnectées, favorisent surtout la présence d’espèces d’oiseaux des milieux agricoles. Dans l’ensemble, ces résultats soulignent l’intérêt de l’IBCR pour évaluer rapidement les principales caractéristiques des boisements riverains et les capacités d’accueil associées, au moins pour les communautés d’oiseaux.

Towards unravelling the Rosette agent enigma: Spread and emergence of the co-invasive host-pathogen complex, Pseudorasbora parva-Sphaerothecum destruens

Thu, 30 Sep 2021 10:18:44

The emergence of non-native fungal pathogens is a growing threat to global health, biodiversity, conservation biology, food security and the global economy. Moreover, a thorough understanding of the spread and emergence of pathogens among invasive and native host populations, as well as genetic analysis of the structure of co-invasive host populations, is crucial in terms of conservation biology and management strategies. Here we combined extensive catchment sampling, molecular detection tools and genomic signatures to i) assess the prevalence of the rosette agent Sphaerothecum destruens in invasive and native fish populations in contrasting french regions, and ii) characterize the genetic diversity and population structure of its co-invasive and asymptomatic carrier Pseudorasbora parva. Although S. destruens was not detected in all the fish collected its presence in contrasting freshwater ecosystems suggests that the disease may already be widespread in France. Furthermore, our results show that the detection of S. destruens DNA in its asymptomatic carrier P. parva is still limited. Finally, we found that P. parva populations show a homogeneous genetic and geographical structuring, which raises the possibility of the occurrence of successive introduction events in France from their native and invasive range.

Global economic costs of aquatic invasive alien species

Wed, 26 May 2021 10:39:16

Much research effort has been invested in understanding ecological impacts of invasive alien species (IAS) across ecosystems and taxonomic groups, but empirical studies about economic effects lack synthesis. Using a comprehensive global database, we determine patterns and trends in economic costs of aquatic IAS by examining: (i) the distribution of these costs across taxa, geographic regions and cost types; (ii) the temporal dynamics of global costs; and (iii) knowledge gaps, especially compared to terrestrial IAS. Based on the costs recorded from the existing literature, the global cost of aquatic IAS conservatively summed to US$345 billion, with the majority attributed to invertebrates (62%), followed by vertebrates (28%), then plants (6%). The largest costs were reported in North America (48%) and Asia (13%), and were principally a result of resource damages (74%); only 6% of recorded costs were from management. The magnitude and number of reported costs were highest in the United States of America and for semi-aquatic taxa. Many countries and known aquatic alien species had no reported costs, especially in Africa and Asia. Accordingly, a network analysis revealed limited connectivity among countries, indicating disparate cost reporting. Aquatic IAS costs have increased in recent decades by several orders of magnitude, reaching at least US$23 billion in 2020. Costs are likely considerably underrepresented compared to terrestrial IAS; only 5% of reported costs were from aquatic species, despite 26% of known invaders being aquatic. Additionally, only 1% of aquatic invasion costs were from marine species. Costs of aquatic IAS are thus substantial, but likely underreported. Costs have increased over time and are expected to continue rising with future invasions. We urge increased and improved cost reporting by managers, practitioners and researchers to reduce knowledge gaps. Few costs are proactive investments; increased management spending is urgently needed to prevent and limit current and future aquatic IAS damages.

A Proposal to Classify and Assess Ecological Status in Mediterranean Temporary Rivers: Research Insights to Solve Management Needs

Tue, 27 Apr 2021 11:39:04

The biomonitoring methods implemented by water authorities are mostly developed for perennial rivers, and do not apply to temporary rivers (TRs). We propose a new classification for TRs to better assess their ecological status. It arises from the LIFE+ TRivers project, which was conducted in the Catalan and the Júcar Mediterranean river basin districts (RBD). The European Water Framework Directive (WFD) provided two systems to set river types (systems A or B from Annex II), which have been officially used by water authorities across Europe to set “national river types” (NRTs). However, essential hydrological variables for TRs are largely omitted. NRTs established according to the WFD were compared with TR categories obtained by using a rainfall-runoff model, “natural flows prescribed regimes” (NFPRs), and with “aquatic phases regimes” (APRs) calculated by using TREHS software. The biological quality indices currently used in Spain, based on macroinvertebrates and diatoms (IBMWP, IMMI-T, and IPS), were compared with a “general degradation” gradient in order to analyze the two TR river classification procedures (NFPR and APR). The results showed that NRTs did not properly classify TRs, and that the APR classification identified ecologically meaningful categories, especially those related to stagnant phases. Four “management temporary river categories” based on APRs are proposed to be used for water managers to properly assess the ecological status of TRs.

Human impacts on global freshwater fish biodiversity

Mon, 22 Feb 2021 11:15:40

We are increasingly aware of human impacts on biodiversity across our planet, especially in terrestrial and marine systems. We know less about fresh waters, including large rivers. Su et al. looked across such systems globally, focusing on several key measures of fish biodiversity. They found that half of all river systems have been heavily affected by human activities, with only very large tropical river basins receiving the lowest levels of change. Fragmentation and non-native species have also led to the homogenization of rivers, with many now containing similar species and fewer specialized lineages. Freshwater fish represent one-fourth of the world’s vertebrates and provide irreplaceable goods and services but are increasingly affected by human activities. A new index, Cumulative Change in Biodiversity Facets, revealed marked changes in biodiversity in >50% of the world’s rivers covering >40% of the world’s continental surface and >37% of the world’s river length, whereas

Etude de l’effet de l’écobuage sur les cladiaies des marais Bondoux, du Retour et du Coucou (Port-Saint- Louis-du-Rhône) (2021)

Tue, 13 Sep 2022 16:14:17

Les cladiaies constituent un habitat remarquable à échelle européenne et particulièrement sous climat méditerranéen où il est rare. Cette formation végétale dominée par le marisque Cladium mariscus est inscrit en annexe I de la directive européenne 92/43/CEE dite « directive Habitat » sous le nom de « Végétations à marisque 7210-1 » (Bensettiti et al. 2002). Dans les Bouches du Rhône cette formation est bien connue dans les marais de la Crau humide où elle bénéficie des résurgence d’eau douce de la nappe de la Crau, zone d’interface entre la Crau sèche et la Camargue. On y retrouve diverses espèces végétales et animales remarquables, notamment en ce qui concerne les arthropodes terrestres. Les cladiaies, en l’absence de perturbation produisent une biomasse importante ainsi qu’une accumulation des parties végétatives mortes, excluant les autres espèces végétales (Conway 1942). Ces accumulations, combinées avec un fonctionnement hydrologique caractérisé par des faibles amplitudes de fluctuations des niveaux d’eau, conduisent à la formation de sol tourbeux. Dans le site Natura 2000 FR9301596 « Marais de la vallée des Baux et marais d'Arles » cet habitat fait l’objet d’une gestion par brûlage dirigé qui a pour effet de réduire la biomasse produite par le marisque et ainsi « d’ouvrir » le milieu, favorisant également les repousses plus appétences pour le bétail. Cette gestion est notamment liée à la vocation cynégétique et pastorale de ces marais. Bien que certains de ses effets aient été étudiés localement (effet sur Baccharis halimifolia : Gortot 2003, effets sur le Butor étoilé : Poulin et al. 2005, effets sur les araignées : Vajda 2004), l’impact du brûlis sur le marisque et les communautés végétales associées est encore mal connu et mérite une étude spécifique. C’est dans ce cadre que la Tour du Valat a réalisé la présente étude, commandité par le Parc Naturel Régional de Camargue. Elle vise à évaluer l’impact de l’écobuage, via une approche synchronique, sur (1) la structure de la Cladiaie et (2) les communautés végétales à marisque. La question générale posée est celle de la résilience au feu des formations à marisque et par conséquent celle de la durabilité de ce mode de gestion ainsi que ses conséquences sur l’état de l’habitat au sein du site NATURA 2000.

Impacts of Plastic Pollution on Freshwater Aquatic, Terrestrial and Avian Migratory Species in the Asia and Pacific Region (2021)

Thu, 16 Sep 2021 09:17:32

This study identifies the impacts of plastic pollution on land and freshwater migratory species protected by the Convention on the Conservation of Migratory Species of Wild Animals (CMS. Plastic pollution is a global issue with plastic waste flowing into oceans from rivers. However, not all plastic pollution reaches the ocean, and can impact species that live in and around river basins. Plastic pollution is a particular problem in the Asia-Pacific region. Two case studies in the report focus on the species of the Mekong and the Ganges. The report calls for more effective waste management, recycling, and design of products, preventing plastic pollution at the source. It also cites the need for increased research efforts to understand the negative effects of plastic pollution on organisms and ecosystems, particularly on terrestrial species that have been poorly studied. Prepared for the CMS Secretariat by the National Oceanography Centre (NOC), this publication is a significant first step towards closing the knowledge gap on the impacts of plastic pollution on CMS-listed species in terrestrial and freshwater ecosystems in the Asia-Pacific region.

Le géant d'eau douce. A la recherche du Silure glane (2021)

Wed, 9 Jun 2021 10:28:38

Une immersion en eau douce, et un livre sous forme de récit, pour faire connaissance avec un poisson surprenant et hors norme : le silure glane. Comment vit-il ? Que mange-t-il ? Est-il une menace pour d'autres espèces ? Nous sommes encore loin de tout connaître de ce poisson d'eau douce, le plus gros d'Europe, mais, prendre le temps de partager ce que nous savons et ce que nous ignorons encore permettra de réduire les préjugés et d'aborder plus sereinement les questions délicates de gestion qu'il pose.

Rapport final du projet "Etude de l'équilibre hydrologique entre les apports d'eau douce et d'eau salée dans le système Vaccarès et les étangs et marais des salins de Camargue" (2021)

Wed, 26 May 2021 10:39:21

Le site des étangs et marais des salins de Camargue (EMSC) a été acquis par le Conservatoire du littoral entre 2008 et 2012 (6500 ha). La plus grande partie de ce site est constituée d’anciens salins, où d’importants travaux hydrauliques (création d’ouvrages, créations de chenaux, décloisonnement d’étangs, etc.) ont été mis en œuvre dans le but de restaurer la connectivité avec la mer au sud et l'hydrosystème Vaccarès au nord. La dynamique hydro-saline joue un rôle prépondérant dans le fonctionnement des écosystèmes lagunaires. Cette dynamique est très complexe pour les EMSC et l'hydrosystème Vaccarès, sujets à de nombreuses entrées et sorties d'eau douce et d'eau salée. A l'heure actuelle, les gestionnaires disposent de connaissances sur le fonctionnement hydro-salin global de l'hydrosystème Vaccarès, et sur le fonctionnement hydraulique des EMSC . Cependant, les conséquences de la reconnexion hydraulique récente de ces deux zones sur leurs dynamiques hydro-salines respectives, et sur celle de l'ensemble de cette "nouvelle entité hydraulique" de 16000 ha, ne sont quant à elles pas bien connues. Les gestionnaires ont donc besoin d'avoir des éléments quantitatifs sur les conséquences que vont avoir : - la reconnexion hydraulique récente entre l'hydrosystème Vaccarès et les EMSC, - - les différents choix de gestion de l'eau sur ces espaces (travaux hydrauliques, gestion des ouvrages, aménagements des bassins versants, ...), - les changements climatiques à venir. Le projet décrit dans ce rapport consiste donc à développer un modèle hydro-salin de l'ensemble de cette zone afin d'en caractériser les dynamiques en termes de salinité et de temps de résidence (exprimant le degré de confinement des différents étangs). L'outil développé permettra à l'avenir d'étudier la dynamique "eau douce / eau salée" de ce vaste système, en fonction des forçages marin, météorologique (pluie, évapotranspiration, vent), et des choix de gestion de l'eau (ouvrages hydrauliques, bassins versants limitrophes). Ce modèle pourra in fine être utilisé pour guider les gestionnaires sur la gestion à mettre en œuvre sur cette zone et sur les conséquences des changements climatiques à venir. Par ailleurs, le modèle développé dans ce projet est une étape indispensable aux futures études à mener sur cette zone, concernant la dynamique des herbiers, le devenir des produits phytosanitaires et des nutriments, la dynamique hydro-sédimentaire du site, la dynamique des peuplements de poissons.

Réussir l’aménagement de son territoire en préservant la biodiversité aquatique (2021)

Wed, 12 May 2021 10:46:50

Dans le cadre de la mise en œuvre de la mission Observatoire Régional de l’Eau et des milieux aquatiques, les partenaires ont souhaité alerter et sensibiliser les collectivités aux enjeux et aux pressions que subit la biodiversité aquatique. Région Sud Provence Alpes Côte d’Azur, Agence de l’Eau Rhône Méditerranée Corse, Office Français de la Biodiversité, Agence Régionale de la Biodiversité et de l’Environnement Provence Alpes Côte d’Azur, Association Régionale des Fédérations de Pêche et Protection des Milieux Aquatiques de Provence Alpes Côte d’Azur, Maison Régionale de l’Eau et Tour du Valat ont uni leurs forces pour rédiger ensemble un document permettant de prendre conscience de ces enjeux et pressions, de donner des exemples d’actions conduites par des collectivités et surtout de donner l’envie et les moyens d’agir pour préserver cette biodiversité aquatique essentielle à nos territoires.

The Potential of Barrier Removal to Reconnect Europe’s Rivers (2021)

Tue, 27 Apr 2021 11:39:24

European rivers are the most fragmented in the world, leading to the loss of critical biodiversity, and driving fish and other freshwater species towards extinction. In 2020, the EU-funded AMBER project recorded over 600,000 barriers on rivers and streams across Europe and estimated that the total number of barriers may be more than 1 million. This suggests the necessity of further improvements to the river continuum to overcome the massive fragmentation of rivers. The removal of river barriers--namely ramps, weirs and dams--is a significant and effective measure to restore the river continuum for biota and sediment, as proposed by the EU Biodiversity Strategy for 2030. This study proposes an initial assessment of the number of river barriers in Europe which could be prioritised for removal and the expected outcome of such removal, based on a sample of 30,000 barriers (less than 3% of the total estimated number of barriers) in large and medium-sized rivers. The report focuses on the reconnection potential, i.e. the length and the ecological quality of reconnected rivers which could be achieved through barrier removal. Some of the barriers with particular uses, such as drinking water reservoirs or hydropower plant of a capacity > 10MW, are excluded where feasible. Out of over 30,000 assessed barriers along larger rivers across Europe 1, the study identifies 858 barriers with high reconnection potential in large and medium- sized rivers, which would allow to reconnect about 14,400 km of rivers. In the EU27, this figure would amount to 732 barriers with high reconnection potential, allowing to reconnect 11,500 km of rivers.

Riparian forests can mitigate warming and ecological degradation of agricultural headwater streams

Wed, 10 Mar 2021 16:47:01

Riparian forests are commonly advocated as a key management option to mitigate the effects of agriculture on headwater stream biodiversity and ecosystem functions. However, the benefits of riparian forests might be reduced by uninterrupted catchment-scale pollution. We studied the effects of riparian land use on multiple ecological endpoints in headwater streams in an agricultural landscape. We studied stream habitat characteristics, water temperature and algal accrual, and macrophyte, benthic macroinvertebrate and fish communities in 11 paired forested and open agricultural headwater stream reaches that differed in their extent of riparian forest cover but had similar water quality. Hydromorphological habitat quality was higher in forested reaches than in open reaches. Riparian forest had a strong effect on the summer water temperature regime, with maximum and mean water temperatures and temperature variation in forested reaches substantially lower than in open reaches. Macrophyte communities differed between forested and open reaches. The mean abundance of bryophytes was higher in forested reaches but the difference to open reaches was only marginally significant, whereas graminoids were significantly more abundant in open reaches. Within-stream dissimilarity of benthic macroinvertebrate community structure was significantly related to the difference in riparian land use between reach pairs. The relative DNA sequence abundance of pollution-sensitive Ephemeroptera, Plecoptera, and Trichoptera species tended to be higher in forested reaches than in open reaches. Finally, fish densities were not significantly different between forested and open reaches, although densities were higher in forested reaches. This unequivocal evidence for the ecological benefits of forested riparian reaches in agricultural headwater streams suggests that riparian forest can partly mitigate the adverse impacts of agricultural diffuse pollution on biota. The strong effect of forests on stream water temperature suggest that riparian forest could also mitigate harmful effects on headwater stream biodiversity and ecosystem functions of the predicted more frequent high summer temperatures.

Early settlement and growth of stocked European glass eels in a fragmented watercourse

Thu, 12 Nov 2020 11:41:44

One of the actions that has been implemented to support the recovery of the panmictic population of European eel is stocking of waterbodies where natural recruitment is low or null. However, growth conditions of the stocked eels can vary greatly. This circumstance emphasises the importance to determine ideal habitat conditions to contribute to the success of stocking actions and, consequently, to increase the production of silver eels. This study aims to evaluate the early settlement and growth of stocked glass eels in the upper reaches of a fragmented river. Stocking was carried out, in 2014, at three sites of an inland tributary of the Mondego river basin (Central Portugal), and its monitoring was conducted during the following two years, until 2016, along with the collection of environmental and hydromorphological parameters. The results showed a successful dispersion throughout the study area. Growth varied spatially, although environmental parameters have not clearly explained this variation, but overall with high growth rates and a positive allometric growth in this early stage of stocking, suggesting a good condition of the stocked individuals. This study showed that these upper reaches of fragmented watercourses, a shared feature amongst most European rivers that are currently inaccessible for natural recruitment, may be suitable habitats for eel stocking.

Rivers’ natural reservoirs: new inputs to the classification of Mediterranean and Saharan wetlands

Fri, 20 Nov 2020 16:38:38

This article is dedicated to natural reservoirs, widely distributed ecosystems in North Africa but poorly studied. Their hydrological and ecological characteristics are insufficiently highlighted in existing wetland typologies; that’s why we recommend to assign them to new wetlands’ types. Generally named gueltas, these reservoirs have a common genesis model, based on natural dams that block river beds. Four types of gueltas are identified: (1) landslide lakes, mountainous reservoirs created upstream of voluminous landslides that block deep valleys; (2) river gueltas, river beds blocked by small deposit thresholds, generally installed by tributaries; (3) dune gueltas, generated upstream to active Saharan dunes; (4) estuarine gueltas, due to fluviomarine dikes transforming estuaries into large ‘saltwater ponds’. These standing waters are built in river beds, and their characteristics and communities are highly fashioned by floods, both in their composition and functioning. The river gueltas are widely distributed in North Africa, while other reservoirs are poorly represented, some of them being threatened. Permanent reservoirs, in both mountains and desert, host endemic fishes, while river gueltas are conservatories of fish during dry seasons. Considering these originalities and values, several Moroccan gueltas have been classified in Ramsar sites, hoping they would benefit from future studies.

Safeguarding Freshwater Life Beyond 2020: Recommendations for the New Global Biodiversity Framework from the European Experience

Wed, 30 Sep 2020 10:25:13

The drafting of a new Global Biodiversity Framework for the Convention on Biological Diversity (CBD) and Biodiversity Strategy for the European Union (EU) render 2020 a critical crossroad for biodiversity conservation. Freshwater biodiversity is disproportionately threatened and poorly studied relative to marine and terrestrial biota, despite providing numerous essential ecosystem services. The urgency of the mounting freshwater biodiversity crisis necessitates approaches catered to the unique ecology and threats of freshwater life, which are not adequately addressed by current strategies. We present a set of 15 special recommendations for freshwater biodiversity to guide the CBD’s post-2020 framework and the 2020 EU strategy based on European case studies, both challenges and successes. Our recommendations cover key outcomes and guiding concepts, enabling conditions and methods of implementation, planning and accountability modalities, and cross-cutting issues. They address topics including invasive species, integrated water resources management, strategic conservation planning, data management, and emerging technologies for freshwater monitoring, among others. These recommendations will enhance the ability of global and European post-2020 biodiversity agreements to halt and reverse the rapid global decline of freshwater biodiversity.

A review of the influence of beaver Castor fiber on amphibian assemblages in the floodplains of European temperate streams and rivers

Fri, 7 May 2021 18:49:27

Once widespread throughout Eurasia and hunted nearly to extinction, the Eurasian beaver Castor fiber has returned to large parts of its former range, largely through active conservation measures. Beavers can substantially alter small, low order streams and their floodplains through dam construction, burrowing activities and tree felling. Therefore, it is presumed they can significantly influence amphibian distributions, species richness and numbers. We undertook a literature review to compare the available data addressing the effects of beaver dams on amphibians in streams of central temperate and boreal Europe. All 19 amphibian species occurring in the study region were found in beaver ponds, despite their distinctly different habitat requirements. Amphibian species acting as pioneers / early colonisers were under-represented in beaver ponds compared to typical forest species. Open country and ubiquitous species showed intermediate patterns. Beaver ponds in headwater streams often supported the entire spectrum of species occurring in the surrounding landscape, and species numbers in beaver modified headwater streams were comparable to those in floodplains of larger natural rivers. In small headwater streams, beavers tended to be the primary providers of essential habitat for amphibians. In contrast, beaver ponds in the floodplains of larger rivers appeared to have less effect and supported lower average species numbers compared to beaver ponds in headwater streams. We propose that beavers and their habitat creating activities are pivotal determinants of amphibian species richness in the headwater streams, which account for 60–80 % of the water bodies in catchment areas in temperate Europe. By creating habitat for endangered amphibian species, beavers and their ability to modify habitats offer extensive opportunities to implement many aspects of the European Water Framework Directive across the continent and to restore amphibian habitats, contributing to their long-term conservation.

Languedoc lagoon environments and man: Building a modern analogue botanical macroremain database for understanding the role of water and edaphology in sedimentation dynamics of archaeobotanical remains at the Roman port of Lattara (Lattes, France)

Mon, 22 Jun 2020 11:18:07

A new method to evaluate archaeological wetland sites in a more objective way was tested. Different wetland environments have been sampled in areas of a nature reserve and their macroremain content analysed to build a modern analogue dataset. This dataset was then used to characterise archaeological samples from a navigation channel from the Roman port city Lattara. In the modern analogue samples, the different wetland types (saline/brackish or fresh water) could be differentiated in the correspondence analysis. Within these groups, the sampled area of the littoral (submerged, shoreline, unsubmerged) could also be differentiated. This dataset can therefore provide a basis for the interpretation of the nature and degree of aquatic influence and layer formation processes in archaeobotanical records of coastal sites. In the tested archaeological samples from the navigation channel of Lattara, changes in space and time could be tracked using the modern analogue dataset and geoarchaeological information. The channel lost its fresh water supply and silted up over a short period of time (approx. 100 years).

Scientists’ warning to humanity on the freshwater biodiversity crisis

Tue, 16 Jun 2020 16:58:56

Freshwater ecosystems provide irreplaceable services for both nature and society. The quality and quantity of freshwater affect biogeochemical processes and ecological dynamics that determine biodiversity, ecosystem productivity, and human health and welfare at local, regional and global scales. Freshwater ecosystems and their associated riparian habitats are amongst the most biologically diverse on Earth, and have inestimable economic, health, cultural, scientific and educational values. Yet human impacts to lakes, rivers, streams, wetlands and groundwater are dramatically reducing biodiversity and robbing critical natural resources and services from current and future generations. Freshwater biodiversity is declining rapidly on every continent and in every major river basin on Earth, and this degradation is occurring more rapidly than in terrestrial ecosystems. Currently, about one third of all global freshwater discharges pass through human agricultural, industrial or urban infrastructure. About one fifth of the Earth’s arable land is now already equipped for irrigation, including all the most productive lands, and this proportion is projected to surpass one third by midcentury to feed the rapidly expanding populations of humans and commensal species, especially poultry and ruminant livestock. Less than one fifth of the world’s preindustrial freshwater wetlands remain, and this proportion is projected to decline to under one tenth by midcentury, with imminent threats from water transfer megaprojects in Brazil and India, and coastal wetland drainage megaprojects in China. The Living Planet Index for freshwater vertebrate populations has declined to just one third that of 1970, and is projected to sink below one fifth by midcentury. A linear model of global economic expansion yields the chilling prediction that human utilization of critical freshwater resources will approach one half of the Earth’s total capacity by midcentury. Although the magnitude and growth of the human freshwater footprint are greater than is generally understood by policy makers, the news media, or the general public, slowing and reversing dramatic losses of freshwater species and ecosystems is still possible. We recommend a set of urgent policy actions that promote clean water, conserve watershed services, and restore freshwater ecosystems and their vital services. Effective management of freshwater resources and ecosystems must be ranked amongst humanity’s highest priorities.

Protected areas and freshwater biodiversity: a novel systematic review distils eight lessons for effective conservation

Tue, 17 Dec 2019 17:38:59

Protected areas are a global cornerstone of biodiversity conservation and restoration. Yet freshwater biodiversity is continuing to decline rapidly. To date there has been no formal review of the effectiveness of protected areas for conserving or restoring biodiversity in rivers, lakes, and wetlands. We present the first assessment using a systematic review of the published scientific evidence of the effectiveness of freshwater protected areas. Systematic searches returned 2,586 separate publications, of which 44 provided quantitative evidence comprising 75 case studies. Of these, 38 reported positive, 25 neutral, and 12 negative outcomes for freshwater biodiversity conservation. Analysis revealed variable relationships between conservation effectiveness and factors such as taxa assessed, protected area size and characteristics, International Union for Conservation of Nature (IUCN) protected area category, and ecoregion. Lack of effectiveness was attributed to many anthropogenic factors, including fishing (often with a lack of law enforcement), water management (abstraction, dams, and flow regulation), habitat degradation, and invasive non-native species. Drawing on the review and wider literature we distil eight lessons to enhance the effectiveness of protected areas for freshwater biodiversity conservation. We urge policymakers, protected area managers, and those who fund them to invest in well-designed research and monitoring programs and publication of evidence of protected area effectiveness.

Bending the Curve of Global Freshwater Biodiversity Loss: An Emergency Recovery Plan

Mon, 8 Feb 2021 11:35:53

Despite their limited spatial extent, freshwater ecosystems host remarkable biodiversity, including one-third of all vertebrate species. This biodiversity is declining dramatically: Globally, wetlands are vanishing three times faster than forests, and freshwater vertebrate populations have fallen more than twice as steeply as terrestrial or marine populations. Threats to freshwater biodiversity are well documented but coordinated action to reverse the decline is lacking. We present an Emergency Recovery Plan to bend the curve of freshwater biodiversity loss. Priority actions include accelerating implementation of environmental flows; improving water quality; protecting and restoring critical habitats; managing the exploitation of freshwater ecosystem resources, especially species and riverine aggregates; preventing and controlling nonnative species invasions; and safeguarding and restoring river connectivity. We recommend adjustments to targets and indicators for the Convention on Biological Diversity and the Sustainable Development Goals and roles for national and international state and nonstate actors.

Les estuaires et les deltas, version 2020. Bulletin bibliographique (2020)

Tue, 27 Apr 2021 11:39:43

Les estuaires et les deltas constituent l’interface terre-mer de nos fleuves ; les premiers sous l’influence forte de la marée, les seconds sous l’influence forte des dépôts sédimentaires. Depuis des siècles, ils sont le siège des activités humaines les plus intenses : voies de navigation, d’échanges culturels et économiques (ports), enjeux militaires stratégiques, espaces riches (économie de subsistance, pêche, chasse, cueillettes, et économie de production salicole, aquacole et agricole), ils ont été l’objet de très nombreux aménagements. Poldérisations et endiguements successifs ont permis d’exploiter les terrains humides de bordure des estuaires, et les espaces de divagation des deltas. Les systèmes portuaires et l’urbanisation ont étendu leur emprise, tandis que les lits estuariens et deltaïques faisaient l’objets de dragages pour la circulation des navires et l’extraction de sables et graviers pour les matériaux de construction. Ces espaces dotés d’une biodiversité et d’une productivité naturelle considérables ont atteint des états de vulnérabilités importants, et leur résilience demeure difficile à évaluer. Dans le contexte de changement climatique, la pression marine croissante complexifie l’analyse de sensibilité de ces milieux. Il faut pourtant envisager d’effectuer dans un avenir proche des actions de restaurations, dans le cadre ou non de compensations réglementaires. Il est urgent de réintégrer ces milieux au cœur d’une politique de préservation des faciès littoraux. Ces infrastructures naturelles méritent de retrouver la place qui est la leur dans les équilibres côtiers. Cela doit pouvoir s’appuyer sur des recherches académiques (à poursuivre : sédimentologie, hydrodynamique et biologie) qui alimenteront des pratiques de génie écologique appropriées, cela dans une optique de gestion durable et adaptative. Les Pôles relais s’emploient à capitaliser ces savoir pour les mettre à disposition des gestionnaires et aménageurs afin de les accompagner dans la renaturation de ces écosystèmes et assurer la pérennité de leurs fonctionnements équilibrés. Ce bulletin bibliographique recense les documents disponibles dans les bases documentaires des Pôles-relais zones humides sur cette thématique.

The AMBER Barrier Atlas. A Pan-European database of artificial instream barriers. Version 1.0 (2020)

Sun, 20 Dec 2020 19:05:42

An overview of all barriers in European rivers: Throughout Europe, there is inconsistent and incomplete data on how many barriers currently exist. Thus, the magnitude of river fragmentation in Europe is almost unknown. An essential first step of the AMBER project was to create an inventory of barriers within European rivers— a Pan-European Atlas of In-Stream Barriers. To date, this map is the most comprehensive overview of available information on barriers in Europe. There are over half a million recorded barriers fragmenting our rivers. However, through field validation, we estimate that there may be well over 1 million barriers in Europe's rivers

La pollution plastique - De nouvelles connaissances et des pistes pour l’action publique (2020)

Thu, 12 Nov 2020 11:42:05

Bien visibles ou microscopiques, les plastiques sont désormais disséminés partout à la surface du globe. Comment retracer et quantifier leurs flux depuis les cours d'eau jusqu'en mer ? Quels sont les impacts de cette pollution sur le vivant ? Comment limiter ses effets et la réduire à la source ?... Telles sont les problématiques abordées dans cet ouvrage à travers les récentes avancées de la recherche française et les retours d'expériences de divers acteurs.

Environmental water requirements of wetlands and their importance for river basin management in the Mediterranean, including the effects of climate change on natural water flow. (2020)

Tue, 13 Oct 2020 18:12:10

To achieve long-term conservation goals and objectives, investment in the knowledge and capacitiy of wetland managers is as critical as investment in direct conservation measures. Without this investment in people at all levels (from government staff to local wetland managers), there will be little chance of securing the wise use of wetlands. In essence, long-term sustainable wetland use and management depend on building essential human and social capital. This Briefing note, developed by the Specialist Group on Water (WaterSG) of the Scientific and Technical Network of MedWet (MedWet/STN), introduces a cognitive framework for the quantity, quality and timing of water flows required to sustain wetlands in the Mediterranean region. The aim of this note is to support the conservation and the sustainable wise use of Mediterranean wetlands, in accordance with the implementation of the Ramsar Convention. This document includes both theoretical and practical information, reporting on specific case studies from the Mediterranean region, and provides tailor-made management recommendations to support and serve both site managers and policy makers to assist them in developing and implementing adaptation strategies in the face of climate change.

The Living Planet Index (LPI) for migratory freshwater fish - Technical Report (2020)

Wed, 2 Sep 2020 17:30:20

Migratory freshwater fish (i.e. fish that use freshwater systems, either partly or exclusively) occur around the world and travel between critical habitats to complete their life cycle. They are disproportionately threatened compared to other fish groups but global trends in abun- dance, regional differences and drivers of patterns have not yet been comprehensively described. Using abundance information from the Living Planet Database, we found widespread declines between 1970 and 2016 in tropical and temperate areas and across all regions, all migration categories and all populations. Globally, migratory freshwater fish have declined by an average of 76%. Average declines have been more pronounced in Europe (-93%) and Latin America & Caribbean (-84%), and least in North America (-28%). The percentage of species represented was highest in the two temperate regions of Europe and North America (almost 50%). For the continents of Africa, Asia, Oceania, and South America, data was highly deficient, and we advise against making conclusions on the status of migratory freshwater SUMMARY fish in these areas. Potamodromous fish, have declined more than fish migrating between fresh and salt water on average (-83% vs -73%). Populations that are known to be affected by threats anywhere along their migration routes show an average decline of 94% while those not threatened at the population level have increased on av- erage. Habitat degradation, alteration, and loss accounted for around a half of threats to migratory fish, while over- exploitation accounted for around one-third. Protected, regulated and exploited populations decreased less than unmanaged ones, with the most often recorded actions being related to fisheries regulations, including fishing restrictions, no-take zones, fisheries closures, bycatch reductions and stocking (these were most com- mon in North America and Europe). Recorded reasons for observed increases tended to be mostly unknown or un- described, especially in tropical regions. This information is needed to assemble a more complete picture to assess how declines in migratory freshwater fishes could be reduced or reversed. Our findings confirm that migratory freshwater fish may be more threatened throughout their range than previously documented.

L'état des eaux des bassins Rhône-Méditerranée et Corse (2020)

Thu, 30 Jul 2020 10:29:42

L’agence de l’eau publie son nouveau rapport sur l’état des eaux des bassins Rhône-Méditerranée et de Corse. Près de la moitié des cours d’eau et 85 % des nappes sont en bon état écologique dans le bassin Rhône-Méditerranée, ainsi que 91 % des rivières et 100 % des eaux souterraines en Corse. La mobilisation sur les territoires des collectivités et des acteurs économiques pour diminuer les pressions telles que les pollutions, les prélèvements d’eau excessifs, les dégradations de la morphologie ou le cloisonnement des rivières, commence à porter ses fruits. Mais les aléas climatiques qui s’intensifient perturbent le fonctionnement naturel des cours d’eau, notamment leurs capacités d’épuration. Il y a urgence à moins polluer, moins prélever d’eau et redonner à nos rivières leurs fonctions vitales utiles à l’homme et à la biodiversité.

Modélisation sous Telemac-2D de la dispersion de bactéries antibiorésistantes au sein d'un réseau hydrographique en Camargue (2020)

Wed, 15 Jul 2020 17:31:17

L’antibiorésistance est un des problèmes majeurs de santé publique à gérer dans les prochaines décennies. L’objectif de ce stage a été d’étudier la dispersion de ces bactéries particulières dans un compartiment complexe qu’est l’eau au travers du milieu hydrographique camarguais. L’établissement d’un modèle hydraulique sous Telemac-2D et BlueKenue a été nécessaire pour cela. La dispersion a été modélisée sur des données environnementales réelles récupérées à l’aide d’une campagne de jaugeage pour les débits et d’une campagne d’échantillonnage microbiologique. Les bactéries ont été cultivées sur des milieux sélectifs comportant des antibiotiques. Les simulations ont été lancées selon l’hypothèse de la station d’épuration en tant que source avec différents indices d’abattement des bactéries. Les résultats ont montré que le pouvoir de dispersion était relativement faible sur un milieu hydrographique présentant un régime de débits particulier (flux et reflux). Les pousses de colonies de bactéries ont été importantes, présentes sur tous les sites et diversifiées. Cette étude a permis de mettre en lumière qu’il existait une grande variété de BAR sur le domaine d’étude, mais là, ou les, sources de ces bactéries n’ont pu être précisément identifiées. L’utilisation de données ponctuelles de jaugeages s’est avérée compliquée au vu du régime très particulier des canaux changeant selon les conditions de vent. Au final, il a été possible de simuler la dispersion de BAR, mais le modèle pourra être renforcé par la mesure en continu des hauteurs d’eau en différents points via des sondes CTD et par des analyses microbiologiques plus avancées.

Threatened Freshwater Fishes of the Mediterranean Basin Biodiversity Hotspot (2020)

Wed, 15 Jul 2020 11:06:39

The Mediterranean Basin Biodiversity Hotspot is among the most biologically diverse regions worldwide and renowned for its richness of endemic freshwater species. But the hotspot’s lakes, rivers and wetlands are seriously threatened by an unprecedented boom in hydropower development. As a result, aquatic ecosystems have become increasingly degraded due to construction of dams and other infrastructure, compounded by a range of other threats. Advocates of this flawed development model repeatedly overestimate economic benefits and ignore severe environmental consequences. In particular, the impacts of small (10 MW) hydropower plants are disproportionately high when offset against their minuscule contribution to global energy production. At least 5,269 hydropower plants are already operating in the region, with 202 currently under construction. A further 6,393 are proposed, including 5,962 small projects, while 1,579 exist and 2,091 are planned within the boundaries of national parks, biosphere reserves, and other protected areas. In order to anticipate the biodiversity impact of this widening hydropower infrastructure it is essential to understand where threatened species are distributed. This report presents detailed range maps for all 251 freshwater fish species presently recognised as threatened in the Mediterranean Basin Biodiversity Hotspot alongside an updated evaluation of their respective extinction risks. The results suggest that an alarming 63% of all threatened freshwater fish species have already been driven closer to extinction by existing hydropower plants, with 55% of all Critically Endangered species highly impacted. Should hydroelectric expansion in the region go ahead as planned, 74% of all threatened freshwater fish species will be negatively impacted, with 65% set to decline due to small projects alone. At least seven of these could become globally extinct in the wild as a result. Hydropower projects, particularly small schemes, are therefore the most important driver of potential fish species extinctions in the Mediterranean Basin Biodiversity Hotspot. Impoundments created by dams and other hydroelectric infrastructure are also the key pathway by which non-native fish species, another major cause of freshwater fish declines, enter fluvial ecosystems. Moreover, if the hydroelectric schemes planned in the Mediterranean Basin Biodiversity Hotspot are implemented, nations will be unable to comply with the United Nations 2030 Agenda for Sustainable Development or binding international biodiversity targets agreed by parties to the Convention on Biological Diversity and European Union member states. There is an urgent need to mitigate the escalating ecological damage triggered by the hydropower binge through preservation and restoration of free-flowing rivers. Rapid and significant action underpinned by sound scientific evidence is required to safeguard freshwater ecosystems and the incredibly rich biodiversity they support throughout the region. By improving the state of the natural environment, the impacts of ongoing climate change would also be reduced. It is hoped that this report will help inform nature conservation, governments and policy-makers to make the right political, financial and consumer choices to reverse the trend of freshwater biodiversity decline throughout the Mediterranean Basin Biodiversity Hotspot.

Floodplains: a natural system to preserve and restore (mars 3, 2020)

Mon, 25 May 2020 12:00:23

From the recent reporting of the second river basin management plans under the Water Framework Directive, it is clear that, across Europe, Member States are not achieving at least good ecological status for their water bodies. In particular, this is because pressures from hydromorphology and diffuse pollution affect one third of water bodies in Europe. On average, approximately 40 % of Europe's surface water bodies achieve good ecological status or potential. Similarly, an analysis of the conservation status of 37 floodplain habitats listed in the Habitats Directive shows that the vast majority have either inadequate or bad conservation status. Across Europe, only 17 % of floodplain habitats and species have good conservation status. These results are in line with global developments that show biodiversity decline that may eventually threaten human well-being. Although difficult to quantify, there is a link between the overall state of natural floodplains and achieving the key objectives of European policies, in particular in the context of the Water Framework, Floods, Habitats and Birds Directives. Floodplain management or protection is encouraged but is only indirectly required under European environmental policies; however, floodplains that are maintained in their natural condition support the achievement of multiple European policy objectives, which are central, among others, to improving biodiversity and ecosystem services.

Reciprocal insights from global aquatic stressor maps and local reporting across the Ramsar wetland network

Wed, 16 Oct 2019 11:03:32

Aquatic ecosystems are exposed to a host of anthropogenic stressors whose combined effect can be synthesized with cumulative stress indices. The reliability of cumulative stress indices depends primarily on: 1) stressor incidence maps derived from remote sensing or modeling but rarely validated against on-the-ground observations, and 2) the weighting scheme used to combine multiple stressors into a cumulative index typically based on expert opinion. In this paper, we evaluate the exposure and weights for 13 aquatic stressor maps of the world’s rivers with a comparison against local stress reporting across 1018 inland and coastal sites from the Ramsar Wetlands of International Importance. We found that globally-mapped and locally-reported stressors are poorly aligned overall (AUC-ROC = 0.50–0.63), and that concordance did not improve when stratifying by ecosystem types or continents. Agreement varied across individual stressors, was highest for hydrological stressors and lowest for habitat disconnectivity stressors. We estimated stressor weights from the comparison and found them to be remarkably aligned well with expert-generated weights, suggesting there is convergence on a stressor hierarchy across local and global scales. Our comparison illustrates the value of integrating data across scales to inform the calculation of global stressor indices. Continued systematic stressor monitoring across environmental observation networks is central to benchmarking maps of ecosystem stress globally.

The Freshwater Jellyfish Craspedacusta Sowerbii Lankester, 1880: An Overview of Its Distribution in France

Mon, 23 Aug 2021 12:34:47

Over the last few decades, reports of the freshwater jellyfish Craspedacusta sowerbii have increased worldwide. This invasive alien species, native to China, has invaded France's freshwater systems. The present article reports the following information regarding this jellyfish: (i) distribution across the French metropolitan territory, (ii) life cycle, physiology and reproductive mode, and (iii) ecology and impact. The main aim of this article is to establish an updated inventory of invaded areas in order to better understand how and why its occurrence is reported with increasing frequency in France. In the 1970s, only 36 sites for Craspedacusta sowerbii were identified. In our study, we observed a widespread distribution of these freshwater jellyfishes in France: 123 sites. Craspedacusta sowerbii was mainly observed in closed ecosystems (ponds - temporary or permanent; basins): 38 ponds, 35 lakes, 14 water-filled quarries and 7 basins and a few in rivers and canals (29 stations).

Do Dialytrichia mucronata and D. saxicola share the same ecological preferences? A case study in the Rhône Valley (France) and possible application for river incision biomonitoring.

Wed, 4 Nov 2020 13:42:01

Anthropization has led to severe river incision in several parts of Europe. Biomonitoring is of interest to characterize this incision or, conversely, the effectiveness of ecological restoration. Mosses of the upper flood zone are good candidates for such biomonitoring as they are small organisms with limited water-intake ability. Here we studied the Dialytrichia mucronata (Brid.) Broth. - D. saxicola (Lamy) M.J. Cano species pair, both mostly encountered in the upper flood zone; the latter was hypothesized to be more resistant to water stress. We analysed 179 bryosociological relevés in the French Rhône River watershed, distributed along a wide ecological interval. We performed Pearson’s Chi-square test to determine whether the latitude, altitude, substrate, and phorophyte had an effect on Dialytrichia (Schimp.) Limpr. species distribution. Assemblages between D. mucronata and D. saxicola and other moss species were tested using a multivariate procedure. Also we compiled a preliminary French departmental scale distribution map for both species. The results showed that the two species differ ecologically and might be more stenoecious than suggested by their wide synecological spectrum. Eighty-three bryophyte species were documented to be associated with the studied species of Dialytrichia. The cumulative projected inertia for the first three axes of the factorial correspondence analysis was only 23.26%, with no clear structuration. It is concluded that neither the relative occurrence of D mucronata and D. saxicola, nor the communities with these species can be used to monitor incision driven changes in vegetation.

Seasonal freshening of NW Mediterranean surface water impacts microbial heterotrophic activity and dissolved organic matter

Mon, 3 Feb 2020 11:49:26

The Rhone river represents the most important source of freshwater, nutrients and organic matter to the northwestern (NW) Mediterranean Sea and riverine input markedly affects biogeochemistry and ecosystem functioning in the estuarine and coastal zone. Structures of low salinity waters (LSW) originating near the river plume can also be transported along the continental shelf and offshore. The objective of the present study was to investigate the influence of LSW distant from their source, focusing on dissolved organic matter (DOM) and related microbial processes during two annual cycles (2007 and 2008) at a time series site characterized by the regular occurrence of LSW in spring (Microbial Observatory Laboratoire Arago). We observed enhanced bacterial heterotrophic production and community respiration and specific DOM features within these LSW, concurrently with low net community production. Our results suggest that LSW represent a mechanism of labile DOM supply, thereby sustaining enhanced heterotrophic microbial metabolism.

Neonicotinoids disrupt aquatic food webs and decrease fishery yields

Tue, 3 Dec 2019 16:19:24

It is now well known that neonicotinoids negatively affect pollinators. As research has expanded, it has become clear that these globally used insecticides directly affect other ecosystem components, including vertebrates. Yamamuro et al. now show that these compounds are indirectly affecting species through trophic cascades (see the Perspective by Jensen). Since the application of neonicotinoids to agricultural fields began in the 1990s, zooplankton biomass has plummeted in a Japanese lake surrounded by these fields. This decline has led to shifts in food web structure and a collapse of two commercially harvested freshwater fish species. The authors argue that such dynamics are likely occurring widely. Invertebrate declines are widespread in terrestrial ecosystems, and pesticide use is often cited as a causal factor. Here, we report that aquatic systems are threatened by the high toxicity and persistence of neonicotinoid insecticides. These effects cascade to higher trophic levels by altering food web structure and dynamics, affecting higher-level consumers. Using data on zooplankton, water quality, and annual fishery yields of eel and smelt, we show that neonicotinoid application to watersheds since 1993 coincided with an 83% decrease in average zooplankton biomass in spring, causing the smelt harvest to collapse from 240 to 22 tons in Lake Shinji, Shimane Prefecture, Japan. This disruption likely also occurs elsewhere, as neonicotinoids are currently the most widely used class of insecticides globally.

Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration

Wed, 16 Oct 2019 11:04:05

Human activities have altered the flow regimes of many of Earth's rivers, with negative impacts on biodiversity, water quality, and ecological processes. In a Review, Palmer and Ruhi explain how restoration designs now attempt to mimic ecologically important aspects of natural flow regimes, guided by insights into how variations in flow affect biota and ecosystem processes. To be successful, such efforts must go beyond accounting for flood pulses to restore natural flow variability and achieve hydrological connectivity between a river and its surroundings.

Stable isotope tracing of links between marine wintering and freshwater breeding habitats of Red-necked Grebes

Wed, 11 Sep 2019 10:31:41

Stable isotope analyses can detect interactions between different stages of the annual cycle in migratory animals. We used carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) isotopes to identify non-breeding environments, the strategy of nutrient allocation to eggs, and potential carry-over effects from wintering areas in Red-necked Grebes Podiceps grisegena breeding in eastern Poland. Strongly positive isotopic signatures in adult grebe feathers compared to freshwater food webs and feathers of locally fledged young suggested that most adults had moulted in marine areas. Enriched isotopic values in the breast muscles of spring-arriving grebes pointed to transfer of marine-derived nutrients to freshwater breeding sites. Isotopic mixing models revealed that egg nutrients were mainly acquired locally. Endogenous nutrients were to some extent mobilised for the formation of albumen (25–26%, 95% credible interval, three-isotope model) and lipid-free yolk (17–18%, two-isotope, δ13C and δ15N model) in early laid clutches, but were little mobilised, if at all, in clutches of females that delayed laying. The non-breeding trophic feeding level, as indexed by δ15N in feathers of grebe females, was related to laying initiation date (greater enrichment, earlier egg production), indicating cross–seasonal effects on reproduction. Both endogenous nutrient transfer to eggs and a high-quality non-breeding diet may facilitate early breeding, which is advantageous in species constrained by short breeding seasons.

Emerging threats and persistent conservation challenges for freshwater biodiversity

Wed, 26 Jun 2019 10:37:54

In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world’s lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth’s surface, these ecosystems host at least 9.5% of the Earth’s described animal species. Furthermore, using the World Wide Fund for Nature’s Living Planet Index, freshwater population declines (83% between 1970 and 2014) continue to outpace contemporaneous declines in marine or terrestrial systems. The Anthropocene has brought multiple new and varied threats that disproportionately impact freshwater systems. We document 12 emerging threats to freshwater biodiversity that are either entirely new since 2006 or have since intensiﬁed: (i) changing climates; (ii) e-commerce and invasions; (iii) infectious diseases; (iv) harmful algal blooms; (v) expanding hydropower; (vi) emerging contaminants; (vii) engineered nanomaterials; (viii) microplastic pollution; (ix) light and noise; (x) freshwater salinisation; (xi) declining calcium; and (xii) cumulative stressors. Effects are evidenced for amphibians, ﬁshes, invertebrates, microbes, plants, turtles and waterbirds, with potential for ecosystem-level changes through bottom-up and top-down processes. In our highly uncertain future, the net effects of these threats raise serious concerns for freshwater ecosystems. However, we also highlight opportunities for conservation gains as a result of novel management tools (e.g. environmental ﬂows, environmental DNA) and speciﬁc conservation-oriented actions (e.g. dam removal, habitat protection policies, managed relocation of species) that have been met with varying levels of success. Moving forward, we advocate hybrid approaches that manage fresh waters as crucial ecosystems for human life support as well as essential hotspots of biodiversity and ecological function. Efforts to reverse global trends in freshwater degradation now depend on bridging an immense gap between the aspirations of conservation biologists and the accelerating rate of species endangerment.

Saltwater intrusion and soil carbon loss: Testing effects of salinity and phosphorus loading on microbial functions in experimental freshwater wetlands

Thu, 7 Mar 2019 16:02:38

Wetlands can store significant amounts of carbon (C), but climate and land-use change increasingly threaten wetland C storage potential. Carbon stored in soils of freshwater coastal wetlands is vulnerable to rapid saltwater intrusion associated with sea-level rise and reduced freshwater flows. In the Florida Everglades, unprecedented saltwater intrusion is simultaneously exposing wetlands soils to elevated salinity and phosphorus (P), in areas where C-rich peat soils are collapsing. To determine how elevated salinity and P interact to influence microbial contributions to C loss, we continuously added P (~0.5 mg P d−1) and salinity (~6.9 g salt d−1) to freshwater Cladium jamaicense (sawgrass) peat monoliths for two years. We measured changes in porewater chemistry, microbial extracellular enzyme activities, respiration rates, microbial biomass, root litter breakdown rates (k), and soil elemental composition after short (57 d), intermediate- (392 d), and long-term (741 d) exposure. After 741 days, both β-1,4-glucosidase activity (P

Freshwater Fishes of Eastern Canada (2019)

Thu, 3 Feb 2022 16:57:02

From the more than one million square miles of the six eastern provinces of Canada 154 species of freshwater fishes have been reported. This edition of Freshwater Fishes of Canada provides the game and commercial fisherman and the naturalist with detailed information regarding these fishes, and assists in the accurate identification of the various species. The species are arranged in order of development: primitive first and the more highly specialized fishes last. Each description includes a picture, a list of other common names, the distinguishing features, size, habitat, life history and habits, food, and additional comments. Technical language has been avoided wherever possible but with no loss of accuracy. In this second edition the author has employed a system of keys for easier identification of families, and of the individuals in the two largest and most difficult species, the trout and minnow groups.

Biodiversité des macroinvertébrés benthiques et évaluation multiparamétrique de la qualité des cours d'eau dans la réserve de biosphère de Belezma (région aride du Nord Est Algérien) (2019)

Wed, 20 Nov 2019 11:43:18

Ce travail a pour objectifs de mettre en évidence la qualité biologique et l’état de santé des cours d’eau du Parc National de Belezma (Réserve de biosphère) à travers des approches multiparamétriques. Nous avons étudié la biodiversité et les traits de vie des macroinvertébrés benthiques dans 36 stations échantillonnées dans 5 oueds, au cours des années 2015, 2017 et 2018 (Oued Hamla, O. Chaaba, O. Bouilef, O. El Ma et O. Rhawet). L’écologie et les patrons de répartition de ces communautés ont été analysés en relation avec les facteurs environnementaux (géolocalisation, qualité des habitats et pression humaine) et la qualité physicochimique de l’eau par le biais de l’analyse de 14 paramètres. L’occupation de l’espace juxtaposant les cours d’eau étudiés est dominée par le type forestier avec des sources de pollution très limitées, dues aux intrants chimiques utilisés dans quelques parcelles cultivées et des rejets urbains de quelques habitants du voisinage. La vitesse de l’écoulement de l’eau est généralement très faible à moyenne. Les habitats recensés sont dominés par les galets. L’eau est de pH moyen (7,46 à 8,05). Les nitrates et les nitrites ne figurent que par des teneurs infimes. L’eau est douce avec un très faible degré de salinité (0,14 % et 0,29 %) et généralement claire (turbidité : 5,2 à 17,66 NTU). Le calcul de l’IBGN montre que la qualité hydrobiologique de l’eau des 5 oueds étudiés est qualifiée de moyenne (IBGN entre 9 et 11). Nous avons recensé un total 102 genres/espèces de macro-invertébrés benthiques répartis sur 4 embranchements, 9 classes, 23 ordres et 66 familles différentes. Parmi les insectes, les groupes les plus dominants en nombre d’espèces sont les diptères (22) suivis des coléoptères (21). C’est à O. Chaaba que les valeurs des indices de diversité sont les plus élevées (S = 62 ; H’ = 4,72 ; indice de Pielou E = 0,79). Le gradient altitudinal varie entre 1045 m et 1500 m. Le nombre d'individus moyen dans les plus basses altitudes (1045 à 1200) est le plus important (nombre d'individus moyen = 102,75). La richesse totale (S) la plus élevée (52 taxons) est notée à plus de 1400 m et la plus importante valeur de l’indice de Shannon (H’= 3,16) est enregistrée pour les altitudes allant de 1300 à 1400 m. Des analyses statistiques modernes faisant appel aux réseaux de neurones (SOM : Self Organisation Maps) et RLQ (Analyse simultanée des traits biologiques, des variables environnementales et de la composition taxonomique) ont été réalisés afin de décrire les modalités de répartition des populations de macroinvertébrés benthiques avec plusieurs niveaux de perception : gradient altitudinal, paramètres environnementaux (qualité de l’eau et de l’habitat), pression humaine et traits de vie. Ceci a notamment permis de décrire les taxons bioindicateurs (polluosensibles et polluorésistants) mettant particulièrement en évidence l’importance capitale du facteur aridité sur l’écologie des peuplements de macroinvertébrés et sur l’état de santé des cours d’eau étudiés. Globalement, la diversité est inférieure par rapport aux régions humides et les variations des facteurs de l’environnement ont des impacts plus évidents (altitude, pollution, variation de l’habitat). Les résultats de ce travail représenteraient un outil judicieux pour orienter des actions de conservation et de gestion de l’aire protégée.

Les roubines (2019)

Fri, 20 Sep 2019 15:09:39

Les marais d'eau douce (2019)

Fri, 20 Sep 2019 14:24:26

Dynamiques des hôtes intermédiaires et des hôtes définitifs impliqués dans les trématodoses en Camargue (2019)

Mon, 9 Sep 2019 17:29:31

Ce travail s’inscrit dans un projet sur les risques épidémiologiques de la fasciolose et autres trématodoses dans un contexte de biologie de la conservation et de perturbations anthropiques, initié depuis quelques années (Sabourin, 2018) et dont les acquis et les suivis permettent de répondre à des problématiques prégnantes dans le système camarguais. Dans le cadre de ces problématiques globales, le stage vise à (1) étudier l’écologie parasitaire des trématodes au sein de l’hôte définitif bovin, sur cette base, (2) identifier les habitats regroupant les conditions favorables pour abriter les mollusques d’eau douce impliqués dans la transmission des trématodes, (3) caractériser les dynamiques spatio-temporelles des populations de ces mêmes mollusques. Pour ce faire, l'auteur a combiné un échantillonnage systématique des parasites du foie lors des abattages des bovins et un suivi de la dynamique des communautés de mollusques d’eau dans des zones hydrologiquement différentes.

Impacts de la gestion de l'eau en Camargue sur les services écosystémiques (2019)

Tue, 3 Sep 2019 11:29:54

Cette étude se focalise sur le socio-écosystème méditerranéen de la Camargue : Ici, la riziculture, par son apport conséquent en eau douce, pourrait contribuer activement à la conservation de la biodiversité et aux services écosystémiques associés. À travers cette étude, nous avons identifié un ensemble de 16 services écosystémiques afin de déterminer l’impact d’une réduction de l’eau douce sur l’ensemble du socio-écosystème de la Camargue. Les méthodes appliquées incluent le développement d’une représentation visuelle de chacun des services, une recherche bibliographique approfondie, une phase d’échange avec 16 experts scientifiques et techniques dans différents domaines et une phase d’entretiens avec huit acteurs locaux visant à valider les représentations de ces services et à étudier les évolutions de ces derniers dans le contexte de notre scénario. Cette étude a permis d’identifier et visualiser les flux de services et les éléments principaux (biophysiques, bénéficiaires et responsable de gestion) dont ils dépendent. Les résultats démontrent que la plupart des services sont liés en s’appuyant sur des éléments communs pour leur flux. Ceci démontre bien la complexité du socio-écosystème camarguais. Cette complexité est la source et le facteur moteur de la richesse culturelle et de la biodiversité qui se trouve actuellement en Camargue.

Guide pour l'élaboration de suivis d'opérations de restauration hydromorphologique en cours d'eau (May 1, 2019)

Mon, 29 Jul 2019 16:07:52

Structuré en trois parties, le guide propose des préconisations de suivi dans le cadre d'opérations de restauration hydromorphologique en cours d'eau. La partie A est dédiée au contexte général, à la définition du suivi, des différentes échelles et de la chronologie du suivi, et au processus de bancarisation des données. La partie B se présente sous la forme de fiches par type d'opération de restauration hydromorphologique, détaillant le suivi à mettre en place. La partie C détaille les différents protocoles à mettre en place et propose des éléments d'interprétation. Le suivi proposé peut être mis en place sur des cours d'eau permanents, de largeur mouillée d'au moins 1 m et prospectables à pied (hors emprise d'une retenue). Ces restrictions sont liées aux limites d'application des différents protocoles.

La Liste rouge des espèces menacées en France – Chapitre Poissons d’eau douce de France métropolitain (2019)

Wed, 17 Jul 2019 15:14:38

Mené dans le cadre de la Liste rouge nationale, cet état des lieux porte sur le risque de disparition de l’ensemble des poissons d’eau douce recensés sur le territoire métropolitain. Après une analyse de la situation de chacune des 80 espèces, les résultats montrent que 15 espèces sont menacées et 16 autres quasi menacées. Neuf ans après la première évaluation, l’actualisation de la Liste rouge des poissons d’eau douce fait apparaître une situation aggravée. Au terme de l'état des lieux, près d'une espèce sur cinq se révèle menacée. Au total, 39 % sont désormais menacées ou quasi menacées contre 30 % en 2010. Les résultats mettent en évidence les pressions multiples pesant sur ces espèces et leurs habitats naturels. La destruction et la dégradation des milieux constituent les principales menaces affectant les poissons d’eau douce.

How effective is protected area designation for the conservation and restoration of freshwater biodiversity? A systematic evidence review. (2019)

Wed, 26 Jun 2019 10:34:05

There is a wide consensus that freshwater biodiversity is continuing to decline rapidly at the global scale, with populations of freshwater species estimated to have declined by 83% since 1970. WWF-UK set-up a quick scoping review (QSR) to provide an informed conclusion on the volume and characteristics of an evidence base and a synthesis of what that evidence indicates in relation to the specific question “How does freshwater biodiversity and habitat change with protected area designation, design and management?”. Key information was captured for each study from the selected publications and input to a searchable database. The majority of studies compared protected with un-protected areas, with only a few comparing the same area before and after designation. Of the 75 case studies, 39 reported positive outcomes, 25 were neutral and 11 were negative, so 52% of the studies showed protected areas to be effective in protecting freshwater biodiversity. Few studies recorded reasons why the protected area had been successful. Detailed analysis of the effectiveness categories did not highlight strong relationships with other information, such as taxa, basis of inference, IUCN protected area category or freshwater ecoregion. However, 73% of the case studies in tropical and subtropical coastal rivers show positive outcomes for protected areas, which exceeds the 52% overall figure. Negative changes in protected area fish biodiversity were recorded only in studies of rivers (i.e. there were none for lakes, ponds, wetlands or floodplains). The main causes were invasive species, variations in natural environmental variables (such as water pH and temperature) and local disturbances from dredging, mining and deforestation. Several studies, including fish in Thai wetlands and birds on Finnish islands, reported that biodiversity increased with greater protected area size. Conserving aquatic habitat, including the hydrological regime (surface and groundwater), water quality, and riparian terrestrial vegetation, was found to be vital for supporting freshwater biodiversity worldwide.

Case Study of the Freshwater Shrimp Atyaephyra Desmarestii (millet, 1831) (crustacea, Decapoda) in the Watershed of Moulouya and Eastern Morocco

Mon, 23 Aug 2021 12:34:47

Considered by some researchers to be invasive in some parts of Europe, the freshwater shrimp Atyaephyra desmarestii has been poorly studied in Morocco. This study reports from the survey of 90 stations situated in the Moulouya watershed and in the Oriental region of the country. Twenty-nine stations, visited three times between 2014 and 2016, reveal the presence of the freshwater shrimp. Twenty-three stations among the 29 showed significant fluctuations in the abundance of the crustacean in time and space. The analysis of the data collected from these 23 stations show that it occupies a large range of habitats, and exhibits a great plasticity against water quality. It concludes that in the watercourses of the Moulouya watershed (even slightly oxygenated), the main factor limiting the geographical distribution of A. desmarestii is the velocity of the water current.

Utiliser la notion de flux admissibles pour gérer les bassins versants fragiles vis-à-vis des phénomènes d'eutrophisation (01/12/2018)

Tue, 29 Jan 2019 16:49:09

L’objectif principal de cette note intitulée est d’apporter des éléments de compréhension et de méthode pour agir dès aujourd’hui sur les émissions de nutriments et ainsi restaurer et préserver les milieux fragiles vis-à-vis des phénomènes d’eutrophisation identifiés dans le SDAGE Rhône Méditerranée (OF5B).

Odonata of the Mazafran hydrosystem: distribution and community structure

Thu, 10 Jan 2019 17:01:19

L’un des objectifs de notre étude est d’acquérir une meilleure connaissance sur les Odonates du réseau hydrographique du Mazafran, situé au centre-nord de l’Algérie. Cette région, jusqu’à présent inexplorée du point de vue odonatologique, se caractérise par un climat méditerranéen subhumide avec une période sèche qui s’étale sur six mois environ, de mai à la fin d’octobre. La prospection de 19 stations réparties dans le réseau hydrographique du Mazafran, sur une durée de 24 mois consécutifs (d’avril 2013 à mars 2015) nous a permis de recenser 948 Odonates adultes appartenant à 15 espèces. Calopteryx haemorrhoidalis (33,1 %) et Platycnemis subdilatata (20,5 %) sont les plus abondantes et les plus fréquentes d’entre elles. Les résultats révèlent la présence d’Ischnura pumilio, qui, actuellement, n’est plus connu en Algérie que de la Numidie (nord-est du pays) et est rare au Maghreb. Les caractéristiques physicochimiques et climatiques des oueds qui composent le réseau hydrographique du Mazafran, ainsi que l’irrégularité des écoulements qui conduisent, notamment, à l’augmentation de la température des eaux en été, ont un impact considérable sur les stations localisées en basse altitude. Combiné aux rejets d’eaux usées urbaines, aux effluents industriels, à la destruction des lits, aux pompages anarchiques de l’eau à des fins agricoles et à la réduction du couvert végétal dont les Odonates sont fortement dépendants, la destruction des habitats, par l’altération de ses composantes (biotiques et abiotiques) s’avère certaine. / One of the objectives of our study is to increase our knowledge of the Odonata in the Mazafran hydrosystem, located in the centre of northern Algeria. This unexplored region in terms of Odonatology, is characterized by its sub-humid Mediterranean climate, and a dry period spread over six months, from May to the end of October. The prospection of 19 sites distributed along the Mazafran hydrographic system during 24 months, from April 2013 to March 2015, allowed us to identify 948 adults involving 15 species. Calopteryx haemorrhoidalis (33.1 %) and Platycnemis subdilatata (20.5 %) were the most abundant and frequent species. The results revealed the presence of Ischnura pumilio, which is currently relatively rare in the overall Maghreb. Both the physicochemical and climatic characteristics of the various wadi influenced the Mazafran hydrographic system. The seasonal change of flow rate led to a dramatic increase in water temperature and had a considerable impact on sites located at low elevation. Cumulative effects of urban and industrial effluents, river bed degradation, illegal pumping of water for agricultural purpose and reduction of riparian canopy influence the Odonata community and lead to a decrease of species richness and diversity. We urge decision-makers to take urgent steps for the restoration of the natural state and functioning of wadi systems throughout Algeria before their irreversible destruction.

A new Chondrostoma species from the Büyük Menderes River Basin, Turkey (Teleostei: Cyprinidae)

Tue, 13 Nov 2018 11:00:25

In a study of the fishes of the Büyük Menderes River Basin, Aegean region of Turkey, two populations of Chondrostoma were found which showed clearly distinctive characters: the population from the Upper B. Menderes (Işıklı Lake) was attributed to C. meandrense Elvira, 1987, while the population from the Çine Stream in the Lower B. Menderes River basin proved to be a hitherto undescribed species: Chondrostoma turnai sp. n. Altogether 24 metric and 7 meristic parameters were compared. The new species is distinguished from C. meandrense and all other cogeners by a combination of the number of lateral line scales, the number of scale rows between the lateral line and the dorsal-fin origin, the number of scale rows of the lateral line and pelvic-fin origin, and the number of gill rakers on the first gill arch.http://www.zoobank.org/urn:lsid:zoobank.org:pub:811C213D-BEDD-4C8C-AE57-BFFA7964781A

Determinants of mercury contamination in viperine snakes, Natrix maura , in Western Europe

Wed, 18 Apr 2018 11:50:49

The effects of Hg contamination are presumably widespread across the components of aquatic ecosystems, but investigations have been mainly focused on freshwater fish, because this biota represents a major source of Hg for human populations. Yet, the possible bioaccumulation of Hg on other freshwater meso- and apex-predators (e.g., amphibians, reptiles) has been largely overlooked, especially in Western Europe. In this study, the determinants of Hg concentrations were assessed for the viperine snake (Natrix maura) across 6 populations (>130 individuals sampled in 2016 and 2017) in France and Spain. Specifically, body size, sex, and diet were compared with Hg concentrations measured in ventral scales. Overall, N. maura accumulated Hg in their scales. Sex did not seem to influence Hg concentrations in this species. Significant differences in Hg concentrations were observed between study sites, and these differences were likely to be mediated by site-specific diet. Frog-eating individuals were characterized not only by lower mean values of Hg (0.194 ± 0.018 μg·g−1 versus 0.386 ± 0.032 μg·g−1 for piscivorous individuals), but also by weaker slopes of the body size-Hg relationship as compared to fish-eating snakes, suggesting strong differences in accumulation rates due to food resources. Importantly, the highest slope of the body size-Hg relationship and the highest values of Hg were found in individuals foraging on trout raised by a fish farm, suggesting that fish farming may contribute to Hg contamination in inland freshwater systems. Finally, our results are compared with data on Hg concentrations in other species of aquatic snakes, in order to provide a comparative point for future studies.

Global extent of rivers and streams

Thu, 23 Aug 2018 13:53:23

The turbulent surfaces of rivers and streams are natural hotspots of biogeochemical exchange with the atmosphere. At the global scale, the total river-atmosphere flux of trace gasses such as carbon dioxide depends on the proportion of Earth’s surface that is covered by the fluvial network, yet the total surface area of rivers and streams is poorly constrained. We used a global database of planform river hydromorphology and a statistical approach to show that global river and stream surface area at mean annual discharge is 773,000 ± 79,000 square kilometers (0.58 ± 0.06%) of Earth’s nonglaciated land surface, an area 44 ± 15% larger than previous spatial estimates. We found that rivers and streams likely play a greater role in controlling land-atmosphere fluxes than is currently represented in global carbon budgets.

History and conservation of Tunisia's largest freshwater wetland: Garâa Sejenane

Wed, 4 Jul 2018 15:20:44

The Garâa Sejenane is an ancient lake in northern Tunisia that currently houses a mosaic of temporary wetlands. Comparison of modern pollen data and field vegetation surveys shows both a weak regional pollen signal and the homogenization of pollen assemblages at the scale of the garâa. Despite a hiatus between 19,000 and 2230 cal. BP, fossil pollen analyses provide the first Tunisian LGM record and attest to the ancient origin of the lake, which housed some taxa still present locally in the 1950s. The originality of the Pleniglacial surrounding landscape dominated by a juniper steppe contrasted with to the mountain conifer forests in Kroumiria. Lastly, analyses of aerial photographs (1948, 1962, 1984), recent satellite photographs and previous botanical descriptions reveal that the lake has been drying since 1960 because of important anthropogenic activities (drainage, groundwater pumping, cultivation, grazing…). These disturbances have generated profound changes in hydrophytic plant communities (fragmentation, diversity loss, introduction of invasive species…) that are likely to threaten their long-term survival.

A Follow-up Report Dealing with the Presence of the Invasive Freshwater Snail Pyrgophorus cf. coronatus in Israel (Mollusca, Gastropoda, Cochliopidae)

Fri, 27 Jul 2018 13:28:24

Response of Submerged Macrophyte Communities to External and Internal Restoration Measures in North Temperate Shallow Lakes

Mon, 26 Feb 2018 15:55:02

Submerged macrophytes play a key role in north temperate shallow lakes by stabilising clear-water conditions. Eutrophication has resulted in macrophyte loss and shifts to turbid conditions in many lakes. Considerable efforts have been devoted to shallow lake restoration in many countries, but long-term success depends on a stable recovery of submerged macrophytes. However, recovery patterns vary widely and remain to be fully understood. We hypothesize that reduced external nutrient loading leads to an intermediate recovery state with clear spring and turbid summer conditions similar to the pattern described for eutrophication. In contrast, lake internal restoration measures can result in transient clear-water conditions both in spring and summer and reversals to turbid conditions. Furthermore, we hypothesize that these contrasting restoration measures result in different macrophyte species composition, with added implications for seasonal dynamics due to differences in plant traits. To test these hypotheses, we analysed data on water quality and submerged macrophytes from 49 north temperate shallow lakes that were in a turbid state and subjected to restoration measures. To study the dynamics of macrophytes during nutrient load reduction, we adapted the ecosystem model PCLake. Our survey and model simulations revealed the existence of an intermediate recovery state upon reduced external nutrient loading, characterised by spring clear-water phases and turbid summers, whereas internal lake restoration measures often resulted in clear-water conditions in spring and summer with returns to turbid conditions after some years. External and internal lake restoration measures resulted in different macrophyte communities. The intermediate recovery state following reduced nutrient loading is characterised by a few macrophyte species (mainly pondweeds) that can resist wave action allowing survival in shallow areas, germinate early in spring, have energy-rich vegetative propagules facilitating rapid initial growth and that can complete their life cycle by early summer. Later in the growing season these plants are, according to our simulations, outcompeted by periphyton, leading to late-summer phytoplankton blooms. Internal lake restoration measures often coincide with a rapid but transient colonisation by hornworts, waterweeds or charophytes. Stable clear-water conditions and a diverse macrophyte flora only occurred decades after external nutrient load reduction or when measures were combined.

Climate change jeopardizes the persistence of freshwater zooplankton by reducing both habitat suitability and demographic resilience

Tue, 6 Mar 2018 16:58:20

Higher temperatures and increased environmental variability under climate change could jeopardize the persistence of species. Organisms that rely on short windows of rainfall to complete their life-cycles, like desert annual plants or temporary pool animals, may be particularly at risk. Although some could tolerate environmental changes by building-up banks of propagules (seeds or eggs) that buffer against catastrophes, climate change will threaten this resilience mechanism if higher temperatures reduce propagule survival. Using a crustacean model species from temporary waters, we quantified experimentally the survival and dormancy of propagules under anticipated climate change and used these demographic parameters to simulate long term population dynamics.

Major River Basins of the World (2018)

Tue, 2 Mar 2021 17:43:36

River basins are the hydrological units of the planet and as such play a critical role in the natural functioning of the Earth. While there have been advances in mapping river basins to facilitate analyses and inform basin management, information on river flow volumes, condition of freshwater habitats and species, as well as the degree of impact on rivers and freshwater biodiversity are still lacking for many parts of the world. This lack of information and, mostly a lack of appreciation for the intrinsic value and role that rivers and wetlands play in the well-being of millions of people, makes their conservation and sustainable management challenging in the face of development pressures and climate change. This chapter summarizes current status and trends in freshwater biodiversity, identifies threats to aquatic ecosystems, provides information of the ecosystem value of wetlands, and makes the case for an improved, and more integrated management and conservation of wetlands.

Freshwater Lakes and Reservoirs (2018)

Tue, 2 Mar 2021 17:43:35

Lakes, ponds, and lacustrine environments are characterized by standing water in depressions of the landscape left by glacier scouring or impoundments along river networks. Depending on their origin and climatic conditions, lakes can be ancient (e.g., African rift lakes) or very young (e.g., recent landslides). The age of most of today’s lakes are in the range of tens of thousands of years old as they were created during the glacier recession of the last ice age (e.g., lakes on or near the Canadian Shield). A handful of largest lakes contain a major proportion of the world’s lake water volume whereas small lakes are more numerous and account for most of lakes surface area. Over time, the natural evolution of lakes is to gradually fill from autochthonous and allochthonous material and sediments. Freshwater lakes, like other surface water ecosystems, offer a wide array of benefits for people, such as water provision, fisheries, flood attenuation, and recreational purposes, and play an important role in global biogeochemical cycles, including water, carbon, and nutrient balances. Overexploitation of freshwater resources threatens the capacity of these ecosystems to provide these benefits in the future.

Freshwater Marshes and Swamps (2018)

Tue, 2 Mar 2021 17:43:34

Freshwater swamps and marshes comprise a large variety of nontidal forested and non-forested wetlands. They have hydric soils and do not accumulate large amounts of peat (noting that the definition of peatlands comprises wetlands with at least 30% dry mass of dead organic material and greater than 30 cm deep). A swamp is dominated by trees and a marsh by emergent herbaceous plants, with both containing a wide variety of submerged and floating-leaved plants. However, the terms have not been used consistently in different parts of the world and many wetlands may contain both treed and non-treed components.

Tidal Freshwater Wetlands: The Fresh Dimension of the Estuary (2018)

Tue, 2 Mar 2021 17:43:34

In the upper reaches of estuaries where rivers end, the constant input from the river creates permanent fresh water conditions even though tidal energy is still present. The physical, chemical and biological conditions differ from the brackish part of the tidal area due to the interaction of the tidal wave with the river ecosystem. Just like in the brackish estuary, tidal freshwater wetlands exhibit gradient variation from tidal flats to higher elevated forests. Chemical processes and accretion are prominent, creating wetlands with high turnover. Many tidal freshwater wetlands have been historically reclaimed for human use as cities, ports, and for agriculture. A diverse flora and fauna is represented and biomass in tidal freshwater wetlands is mostly very high. Because this system is at the interface of salt – fresh conditions, tidal freshwater wetlands are particularly susceptible to sea level rise and global warming.

Freshwater Ecology and Conservation (2018)

Fri, 30 Aug 2019 17:02:17

This practical manual of freshwater ecology and conservation provides a state-of-the-art review of the approaches and techniques used to measure, monitor, and conserve freshwater ecosystems. It offers a single, comprehensive, and accessible synthesis of the vast amount of literature for freshwater ecology and conservation that is currently dispersed in manuals, toolkits, journals, handbooks, 'grey' literature, and websites. Successful conservation outcomes are ultimately built on a sound ecological framework in which every species must be assessed and understood at the individual, community, catchment and landscape level of interaction. For example, freshwater ecologists need to understand hydrochemical storages and fluxes, the physical systems influencing freshwaters at the catchment and landscape scale, and the spatial and temporal processes that maintain species assemblages and their dynamics. A thorough understanding of all these varied processes, and the techniques for studying them, is essential for the effective conservation and management of freshwater ecosystems.

Poissons migrateurs et activités halieutiques dans les zones humides de Corse (2018)

Thu, 31 Jan 2019 14:02:09

- Les politiques et enjeux concernant les poissons en milieux lagunaires et cours d'eau - Etat des connaissances sur les poissons et leurs habitats - Continuité écologique et pratiques de gestion : aspect opérationnel en faveur d'une meilleure gestion piscicole sur les lagunes et les cours d'eau en Corse

Lutter contre les micropolluants dans les milieux aquatiques : quels enseignements des études en sciences humaines et sociales ? (2018)

Tue, 22 Jan 2019 17:31:47

En dépit des progrès pour traiter les eaux usées, de nombreux micropolluants se retrouvent dans les milieux aquatiques. Cette pollution invisible à l'oeil nu contribue à la dégradation de ces milieux et au déclin de certaines espèces. Les recherches en sciences de l'environnement et en ingénierie s'avèrent essentielles pour améliorer notre connaissance des micropolluants et des risques associés et inventer de nouveaux moyens techniques pour mieux les surveiller et limiter leur diffusion dans l'environnement, notamment dans les milieux aquatiques. Ceci étant, cette pollution est également un enjeu de société : ce sont nos modes de production et de consommation qui sont responsables de la contamination des milieux aquatiques. In fine, qu'elle soit ou non accompagnée d'innovations techniques, la lutte contre les micropolluants requiert obligatoirement des changements de pratiques dans le milieu professionnel, l'espace public et à la maison.

Valuing Rivers: How the Diverse Benefits of Healthy Rivers Underpin Economies (2018)

Tue, 22 Jan 2019 17:31:37

This report outlines how the traditionally narrow view of rivers as primarily sources of water and power puts other critical benefits at risk, from freshwater fisheries to natural flood protection for cities and sediment flows that keep the world’s deltas above the rising seas. While these directly benefit hundreds of millions of people, they are often overlooked and remain a low priority for decision makers – until they disappear and crises occur. The report shows how this short-sighted approach that has proven costly across the globe and could result in even greater economic losses in the future. Already, 19 per cent of global GDP comes from watersheds with high or very high water risk, while most of the world’s great deltas – including the Ganges, Indus, Mekong, Nile and Yangtze – are sinking and shrinking.

Les espèces exotiques envahissantes dans les milieux aquatiques. Connaissances pratiques et expériences de gestion. Vol. 3 Expériences de gestion (bis) (2018)

Tue, 20 Nov 2018 11:30:21

Publiés en 2015, les deux premiers volumes présentaient un état des lieux des connaissances sur les espèces exotiques envahissantes et leur gestion (Vol. 1) ainsi qu’un premier ensemble de retours d’expériences de gestion conduites en France métropolitaine et en Europe (Vol. 2), accompagnés de fiches descriptives des espèces. Ils sont désormais complétés par ce troisième volume regroupant les 35 retours d’expériences rédigés entre 2015 et 2018. Portant sur 21 espèces de faune et de flore, dont 12 nouvellement traitées, ce volume comprend également trois retours d’expériences dans les collectivités d’outre-mer. Ces documents sont le fruit d’un travail collectif ayant mobilisé plus d’une centaine de contributeurs et de nouveaux retours sont actuellement en cours d’élaboration.

Les characées, des algues singulières (2018)

Thu, 20 Sep 2018 11:47:56

Les milieux humides et aquatiques continentaux (2018)

Wed, 12 Sep 2018 14:34:55

Définis comme les portions du territoire, naturelles ou artificielles, caractérisées par la présence d’eau, les milieux humides et aquatiques continentaux présentent une grande diversité biologique. Ils fournissent notamment de l’eau, de la nourriture et un abri à un grand nombre d’espèces telles que les amphibiens et les poissons mais également à de nombreux oiseaux, mammifères et insectes. Ces écosystèmes fournissent également des services aux sociétés humaines, que ce soit pour l’alimentation, les possibilités de loisirs et de tourisme ou la maîtrise des crues, etc. S’inscrivant dans le cadre de l’évaluation française des écosystèmes et des services écosystémiques (EFESE), le présent rapport vise à documenter les principales évolutions récentes et à venir de l’état des milieux humides et aquatiques continentaux, les facteurs à l’origine de leur évolution, et à en traduire les implications en termes de bien être et de soutenabilité. Destinés au gestionnaire public mais également au citoyen, ses résultats fournissent des références nécessaires permettant d’éclairer les décisions concernant ces milieux.

The Potential Impacts of Climate Change on Biodiversity in Flowing Freshwater Systems

Thu, 15 Feb 2018 17:21:17

Ongoing increases in air temperature and changing precipitation patterns are altering water temperatures and flow regimes in lotic freshwater systems, and these changes are expected to continue in the coming century. Freshwater taxa are responding to these changes at all levels of biological organization. The generation of appropriate hydrologic and water temperature projections is critical to accurately predict the impacts of climate change on freshwater systems in the coming decade. The goal of this review is to provide an overview of how changes in climate affect hydrologic processes and how climate-induced changes in freshwater habitat can impact the life histories and traits of individuals, and the distributions of freshwater populations and biodiversity. Projections of biological responses during the coming century will depend on accurately representing the spatially varying sensitivity of physical systems to changes in climate, as well as acknowledging the spatially varying sensitivity of freshwater taxa to changes in environmental conditions.

Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters

Thu, 15 Feb 2018 17:16:37

It seems improbable that a thin veneer of attached algae coating submerged surfaces in lakes and rivers could be the foundation of many freshwater food webs, but increasing evidence from chemical tracers supports this view. Attached algae grow on any submerged surface that receives enough light for photosynthesis, but animals often graze attached algae down to thin, barely perceptible biofilms. Algae in general are more nutritious and digestible than terrestrial plants or detritus, and attached algae are particularly harvestable, being concentrated on surfaces. Diatoms, a major component of attached algal assemblages, are especially nutritious and tolerant of heavy grazing. Algivores can track attached algal productivity over a range of spatial scales and consume a high proportion of new attached algal growth in high-light, low-nutrient ecosystems. The subsequent efficient conversion of the algae into consumer production in freshwater food webs can lead to low-producer, high-consumer biomass, patterns that Elton (1927) described as inverted trophic pyramids. Human perturbations of nutrient, sediment, and carbon loading into freshwaters and of thermal and hydrologic regimes can weaken consumer control of algae and promote nuisance attached algal blooms.

European catfish (Silurus glanis) as a freshwater apex predator drives ecosystem via its diet adaptability

Mon, 10 Jan 2022 16:08:30

Apex predators play a key role in ecosystem stability across environments but their numbers in general are decreasing. By contrast, European catfish (Silurus glanis), the European freshwater apex predator, is on the increase. However, studies concerning apex predators in freshwaters are scarce in comparison to those in terrestrial and marine ecosystems. The present study combines stomach content and stable isotope analyses with diet preferences of catfish to reveal its impact on the ecosystem since stocking. Catfish niche width is extremely wide in comparison to the typical model predator, Northern pike (Esox lucius). Catfish and pike have different individual dietary specialization that results in different functional roles in coupling or compartmentalizing distinct food webs. The role of both species in the ecosystem is irreplaceable due to multiple predator effects. The impact of catfish is apparent across the entire aquatic ecosystem, but herbivores are the most affected ecological group. The key feature of catfish, and probably a common feature of apex predators in general, is utilization of several dietary strategies by individuals within a population: long-term generalism or specialization and also short-term specialization. Catfish, similar to other large-bodied apex predators, have two typical features: enormous generalism and adaptability to new prey sources.

How common road salts and organic additives alter freshwater food webs: in search of safer alternatives

Fri, 6 Oct 2017 11:24:58

Increased habitat connectivity homogenizes freshwater communities: historical and landscape perspectives

Fri, 6 Oct 2017 11:24:50

Freshwater bloom-forming cyanobacteria and anthropogenic change

Wed, 27 Sep 2017 12:02:23

This lecture (∼ 45-55 slides) will be aimed at senior undergraduate students and graduate students in aquatic sciences with little background in phycology. This lecture could be used in a Aquatic Ecology or Sciences (Limnology) course, an Ecology course, a Phycology course, Environmental Science. Cyanobacteria that may lead to blooms encompass a wide range of different functional groups. We will present: 1) the evolutionary history of cyanobacteria (2-3 slides) (this helps explain some of their present-day traits) 2) basic biology and physiological/ecological traits of planktonic cyanobacteria that are most often associated with visible biomass accumulations (“blooms”) in freshwater/brackish systems of various regions of the world. Traits to be considered include: capacity for N fixation, nutrient uptake and storage (C, N, P), siderochromes, buoyancy regulation (gas vacuoles, mucilage), life cycles, growth rates vs. loss rates (resistance to grazing), allelopathy (negative vs. positive biotic interactions) Functional groups. Planktonic genera may also produce toxins, contributing to harmful algal blooms. (∼12-14 slides). 3) Cyanotoxins: the principal types of toxins produced and their effects (persistence) will be compared, along with theories as to the biological function of these compounds. (∼ 6 slides) 4) Specific case studies of blooms types under different climates: e.g. scum-forming, metalimnetic, dispersed (∼6) 5) The factors that appear to explain and control cyanobacterial dominance will be presented, including nutrient effects, temperature, and food chain changes. These factors vary across temporal and spatial scales. Evidence for eutrophication and climate change in mediating directly or indirectly the frequency and severity of freshwater cyanobacterial blooms will be considered (∼8-10). 6) Research avenues Controversial or unresolved topics: e.g. invasiveness?, cosmopolitan or geographically restricted (e.g. endemism? in hot spring taxa), toxin concerns and bioaccumulation), nitrogen fixation (“pretenders”), nutrient stoichiometry. Unexplored diversity at different levels (molecular, chemical, taxonomic), techniques for controlling cyanobacteria blooms, the future for cyanobacteria under climate change scenarios (∼4) 7) General references, web resourcess and primary articles. (∼2) 8) Questions and potential experiments for instructors and students will be provided at the end of the lecture (supplementary slides).

Global variation in the beta diversity of lake macrophytes is driven by environmental heterogeneity rather than latitude

Fri, 11 Aug 2017 09:19:00

We studied global variation in beta diversity patterns of lake macrophytes using regional data from across the world. Specifically, we examined (1) how beta diversity of aquatic macrophytes is partitioned between species turnover and nestedness within each study region, and (2) which environmental characteristics structure variation in these beta diversity components. Location Global. Methods We used presence-absence data for aquatic macrophytes from 21 regions distributed around the world. We calculated pairwise-site and multiple-site beta diversity among lakes within each region using SOrensen dissimilarity index and partitioned it into turnover and nestedness coefficients. Beta regression was used to correlate the diversity coefficients with regional environmental characteristics. Results Aquatic macrophytes showed different levels of beta diversity within each of the 21 study regions, with species turnover typically accounting for the majority of beta diversity, especially in high-diversity regions. However, nestedness contributed 30-50% of total variation in macrophyte beta diversity in low-diversity regions. The most important environmental factor explaining the three beta diversity coefficients (total, species turnover and nestedness) was elevation range, followed by relative areal extent of freshwater, latitude and water alkalinity range. Main conclusions Our findings show that global patterns in beta diversity of lake macrophytes are caused by species turnover rather than by nestedness. These patterns in beta diversity were driven by natural environmental heterogeneity, notably variability in elevation range (also related to temperature variation) among regions. In addition, a greater range in alkalinity within a region, likely amplified by human activities, was also correlated with increased macrophyte beta diversity. These findings suggest that efforts to conserve aquatic macrophyte diversity should primarily focus on regions with large numbers of lakes that exhibit broad environmental gradients.

Introduction and invasion of the red-eared slider and its parasites in freshwater ecosystems of Southern Europe: risk assessment for the European pond turtle in wild environments

Fri, 11 Aug 2017 09:18:35

The North American red-eared slider Trachemys scripta elegans, which is nowadays considered among the world’s worst invasive species, could constitute a real threat to native freshwater turtles. Because this species shares the same habitats of the European pond turtle Emys orbicularis since its introduction in the European wetlands, we surveyed populations of both alien and indigenous species in France and Spain in order to determine the diversity of platyhelminth parasites (Monogenea, Polystomatidae) in natural environments and to evaluate the levels of risks associated with parasitism. DNA barcoding procedure based on partial cytochrome c oxydase I sequences revealed ten monogenean parasite species within E. orbicularis populations and/or captive animals among which at least eight could be considered as introduced parasites from American freshwater turtles. Results indicated that host switching could have occurred either in natural environments or in captivity, when indigenous turtles were kept with exotic species, demonstrating that captive turtles could act as reservoirs of parasites. The presence of non-native parasite species within wild populations of E. orbicularis in the European freshwater ecosystems also highlighted the risks that these parasites may pose on the survival of natural turtle’s populations and on the dynamics of native parasites.

Quantifying rapid spatial and temporal variations of CO2 fluxes from small, lowland freshwater ponds

Fri, 8 Jun 2018 12:22:22

Small ponds comprise a substantial portion of the total area of the Earth’s inland waters. They can be powerful carbon sinks or sources, potentially significant processors of organic carbon. Our understanding of their role is constrained by the absence of information regarding their CO2 fluxes (F CO2) and how these change with wet or dry phases and across distinct pond plant communities. We monitored the F CO2 from 26 neighbouring small ponds over a 2-week drying period in late summer in 2014. The mean F CO2 on day 1 (−641 ± 1490 mg m−2 day−1) represented a net intake across the site. As ponds dried they switched to becoming CO2 sources resulting in a net site emission of CO2 by day 12 (3792 ± 2755 mg m−2 day−1) although flux rates did not vary systematically between plant communities. Significant variability in the F CO2 was observed amongst adjacent ponds on individual sampling days, resulting in marked spatial heterogeneity in CO2 processing. This large degree of temporal and spatial heterogeneity across short time periods and small distances highlights the variability in the F CO2 from temporary systems, making it hard to generalize their role in carbon cycle models.

Regard sur l’eau en Provence-Alpes-Côte d’Azur, Observatoire régional eau et milieux aquatiques (2017)

Mon, 18 Jan 2021 13:47:42

Cette publication de l’Observatoire régional de l’eau et des milieux aquatiques de Provence-Alpes-Côte d’Azur a pour vocation de faire découvrir ou mieux connaître les enjeux de l’eau dans notre région aux multiples spécificités. Des informations sur les milieux aquatiques, les ressources en eau, les besoins et les usages, les grands transferts d’eau régionaux, l’aménagement du territoire et les risques liés à l’eau vous y sont proposées au travers de nombreux chiffres-clés et illustrations. Ce panorama régional est ponctué par une présentation des principaux outils et démarches engagés pour une gestion concertée des milieux aquatiques à différentes échelles du territoire

Squalius semae, a new species of chub from the Euphrates River, Eastern Anatolia (Teleostei: Cyprinidae)

Tue, 13 Nov 2018 11:01:19

In a study of the fishes of the Euphrates River (Persian Gulf basin) three species of Squalius belonging to the cephalus-group were found: The Tohma population was identified as S. seyhanensis and the Merzimen and Hilvan populations as S. berak. The comparison of 28 metric and 5 meristic parameters and morphological characters showed that the populations of the northern Euphrates River drainages are distinct and belong to a hitherto unnamed species. We describe it here as Squalius semae sp. n.http://www.zoobank.org/urn:lsid:zoobank.org:pub:D195B69C-C6CB-4DEB-B85D-5B695F917CE5

Risk screening of non-native and translocated freshwater fish species in a Mediterranean-type shallow lake: Lake Marmara (West Anatolia)

Tue, 13 Nov 2018 11:01:08

Risk screening tools to identify species with a high or low risk of invasiveness are being increasingly used for effective management purposes. Amongst the available tools, the Fish Invasiveness Screening Kit (FISK) has been used extensively and successfully in large risk assessment (RA) areas, and was recently upgraded to the new generic tool Aquatic Species Invasiveness Screening Kit (AS-ISK). The aim of the present study was to assess with AS-ISK the invasive potential of introduced non-native and translocated fishes in a Mediterranean-type shallow lake (Lake Marmara) located in west Anatolia (Turkey). Based on independent evaluations of 35 species by two assessors, calibration of AS-ISK resulted in a threshold score of -3.65, which reliably distinguished between potentially invasive (high risk) and potentially non-invasive (medium to low risk) fishes. Of the 35 species assessed, 17 were categorised as ‘low risk’ and included native/endemic and translocated natives, and the remaining 18 as ‘high risk’ and comprised non-natives and translocated natives. Carassius gibelio had the highest score in the Climate Change Assessment section, suggesting that it might potentially impact on the native fish fauna under likely climate change scenarios for the RA area. Some cool water non-native (Oncorhynchus mykiss, Salvelinus fontinalis), translocated native (Luciobarbus lydianus) and endemic species (Ladigesocypris mermere) in the catchment will likely be affected negatively by predicted climate change conditions.

Spatiotemporal trends for exotic species in French freshwater ecosystems: where are we now?

Fri, 8 Jun 2018 14:51:12

We compiled a list of 148 exotic species in French inland freshwaters, comprising 36 plant species and 112 animals, including 50 invertebrates, 7 amphibians, 1 reptile, 25 fish, 22 birds and 7 mammals. Spatial distribution maps and cumulative analyses for most species indicate that exotic plants are distributed more along the west coast of France and, to a lesser extent, the Rhone basin, whereas exotic animals are clearly clumped in the north-east (Rhine Basin). The rate of introductions has increased exponentially over time. The most recent introductions (since 1992) have occurred in the Rhine Basin, from where they have then spread. Twenty-five species on our list are among the ‘100 worst invasive species of Europe’ (DAISIE) and 11 among the worst in the world (IUCN), with six species included on both lists. The potential cumulative impact of exotic species tends to be heterogeneous across France, though the north-east appears to be more disturbed, especially by animal species. Additional research is needed on criteria for prioritising intervention measures that will help stakeholders make objective choices in the management of exotic species in aquatic ecosystems.

Freshwater Key Biodiversity Areas in the north-western Mediterranean sub-region (2017)

Tue, 9 Jan 2018 14:20:03

The Mediterranean Basin biodiversity hotspot is known to be one of the most biologically rich and complex regions on Earth. The north-western part of the hotspot (the area thatcovers all of the Iberian Peninsula, southern France, mostof Italy and Malta) supports important river, lake, karst and wetland systems critical for the survival of threatened and restricted range freshwater species. Within the north-western Mediterranean regionof the hotspot,freshwater Key Biodiversity Areas (i.e.,sites of importance for the global persistence of biodiversity) have been identified.The purpose of this report is to help guide and inform policies and conservation actions for freshwater biodiversity in the region.

The role of waterbirds in the dispersal of aquatic alien and invasive species

Wed, 9 Nov 2016 14:05:15

Aim To review existing literature on the ability of waterbirds to spread aquatic alien and invasive species, and to assess the relevance of bird-mediated dispersal for the conservation of freshwater ecosystems. Location Global. Methods Literature Review. Results A systematic review of the literature revealed that quantitative studies investigating dispersal of alien organisms by waterbirds are rare (n = 14). Most studies citing waterbird dispersal rely on anecdotes or inferences from morphological dispersal syndromes. However, evidence from each stage of dispersal (i.e. emigration, transport and immigration) shows that waterbirds can carry alien plants and invertebrates internally and externally; transport them between water bodies at a variety of spatial scales; and deposit viable propagules in sites suited to aquatic invasive species. Main conclusions Our review suggests that waterbirds can and do act as important dispersal vectors for freshwater invasive species. Further experimental and field based research on the numbers and viability of moved alien propagules, and the roles of different species in the bird community, is needed. Furthermore, consideration of the spatially explicit manner in which birds move is imperative to understanding invasive spread. Populations of alien aquatic species in seemingly isolated wetlands can no longer be considered contained if they are able to be spread through waterbird-mediated dispersal, and containment measures must recognize such opportunities for further spread. Changing waterbird movement patterns, driven by climate and land use change, further add to the challenge of managing invasive species and offers an interesting opportunity for future research. The study of waterbird-mediated dispersal of aquatic alien invasive species provides insights not only into species invasions, but more generally into movement ecology, population ecology and biogeography.

A preliminary appraisal of phylogenetic patterns as a tool for long-term monitoring of plant communities in temporary freshwater rockpools

Fri, 8 Jun 2018 14:52:29

We propose the use of phylogenetic patterns as a tool for monitoring long-term change in plant community structure in small temporary pools, as an alternative to the compilation of species lists across years. This was tested using forty temporary pools from four pool landscapes in Malta. These were followed between November 2014 and April 2015. Each pool was sectored into ‘Aquatic’, ‘Ecotone’ and ‘Terrestrial zones’ and the species present in each zone were recorded. All species data from a landscape were collated by zone, and the net relatedness index (NRI) for the species assemblages in each zone calculated using PHYLOCOM software. The NRI was positive in the ‘Terrestrial’ zones, and negative in the ‘Aquatic’ zones. The ‘Ecotone’ zones followed no discernible pattern. The results suggest that calculating the NRI of plant assemblages in different hydrological zones, and using these phylogenetic ‘signatures’ as a comparative baseline, would be a feasible addition to long-term monitoring programmes for the early detection of long-term environmental changes such as those arising from climatic changes.

A distinct island population of threatened freshwater fish: to split or lump?

Fri, 8 Jun 2018 12:09:04

Freshwater fishes in the Balkans display high percentages of endemic species, many being limited to restricted distributions. Their management, for example, through identification of priority areas for conservation or through re-introduction, is hampered by a poor understanding of their taxonomic diversity and interrelationships. We evaluate the identity of a sand goby belonging to Knipowitschia, limited to a single wetland on the Greek island of Zakynthos. Its representatives morphologically differ sufficiently from their congeners to qualify as a separate species. However, in view of the similarity in mitochondrial ribosomal DNA sequences, the evolutionary plasticity of said morphological characters, and in the absence of a taxonomic revision of the Ionian Ecoregion’s Knipowitschia gobies, describing it as a new species seems unjustified and premature. Rather, we advocate that its unique habitus and its vulnerability as the island’s only resident freshwater fish necessitate conservation efforts as a kind of “phenotypically significant unit”. We also propose sand gobies as flagships for wetlands in the region. This case study suggests a possible approach for fish conservation prioritization in the region, taking a precautionary angle in order to avoid taxonomic inflation, which is an imminent risk given the importance of nominal species and endemics in conservation policy.

Potential exposure routes and accumulation kinetics for poly- and perfluorinated alkyl compounds for a freshwater amphipod: Gammarus spp. (Crustacea)

Tue, 4 Oct 2016 16:01:03

Gammarids were exposed to sediments from a deposition site located on the Rhône River (France) downstream of a fluoropolymer manufacturing plant. Gammarids accumulated to various extents four long-chain perfluoroalkyl carboxylic acids (PFCAs) from C9 to C13, one sulfonate, perfluorooctane sulfonate (PFOS) and three of its precursors (the perflurooctane sulfonamide (FOSA), the N-methyl perfluorooctane sulfonamidoacetic acid (MeFOSAA), the N-ethyl perfluorooctane sulfonamidoacetic acid (EtFOSAA) and the 6:2 fluorotelomer sulfonic acid (6:2 FTSA). Whatever the compound, the steady state was not achieved after a 3-week exposure; elimination was almost complete after a 3-week depuration period for perfluorononanoic acid (PFNA), PFOS, the three precursors and the 6:2FTSA. However, this was not the case for long-chain PFCAs, whose elimination rates decreased with increasing chain length. PFAS accumulation in gammarids occurred via the trophic and respiratory pathways, in proportions varying with the carbon chain length and the terminal moiety.

Freshwater Molluscs in Diet of Hooded Crow (Corvus cornix)

Wed, 4 Jan 2017 10:11:07

ABSTRACT The diet of nestling Hooded Crows (Corvus cornix) was investigated in Warta Mouth National Park (W Poland) in the breeding season of 2003. We analyzed 82 food samples of which 79% contained snails and bivalves. Hooded Crows prefer Viviparus spp. instead of smaller but more abundant molluscan species present in the studied area. We suspect that under conditions of the lowland flooded river valleys Viviparus spp., as a relatively large and meaty species, can be eaten without the shell and is a more valuable food source than smaller molluscs.

Phytoplankton colonization patterns. Is species richness depending on distance among freshwaters and on their connectivity?

Fri, 8 Jun 2018 14:52:26

Phytoplankton assemblages in two Sicilian water bodies were compared to test the hypothesis that colonization events and the successful establishment of a new species in an aquatic ecosystem may depend on the number of water bodies in a given area and on their relative distance. The two ecosystems are both natural, shallow lakes and they are protected sites hosting a rich avifauna. Lake Biviere di Gela is located in an area with a high density of ponds, whereas Lake Pergusa is an isolated waterbody without other aquatic ecosystems in its surroundings. Both lakes had almost disappeared about 10 years ago because of the over-exploitation of their main inflows. They were therefore re-filled using water from other catchments and their phytoplankton has been sampled since their re-filling. The results show that Lake Pergusa has maintained a species-poor phytoplankton assemblage since its re-filling, whereas Lake Biviere di Gela has been showing progressively richer phytoplankton assemblages during time. The composition of samples collected in nearby located temporary ponds suggests that phytoplankton in this area belongs to a species-rich metacommunity which favored its re-establishment in the lake. Aquatic ecosystems conservation plans cannot thus neglect the role of small waters located in the catchments.

Phycogeography of freshwater phytoplankton: traditional knowledge and new molecular tools

Fri, 8 Jun 2018 12:18:26

“Everything is everywhere, but environments selects.” Is this true? The cosmopolitan nature of algae, including phytoplankton, has been highlighted in many textbooks and burnt into the minds of biologists during their studies. However, the accumulating knowledge on the occurrence of individual phytoplankton species in habitats where they have not been seen before, reports on invasive phytoplankton species, and the increasing number of papers with phylogenetic trees and tracing secondary metabolites, especially cyanotoxins, contradict. Phytoplankton species, with rare exceptions, are neither cosmopolitan, nor ubiquists. In this review paper, we provide an overview of the basic patterns and the processes relevant for biogeography of freshwater phytoplankton. The following topics are considered: dispersal agents and distances; survival strategies of species; geographic distribution of different types; patterns of invasions; tools of molecular genetics; and metabolomics to explore dispersal patterns, island biogeography, and associated species–area relationships for algae.

A skeletochronological study of age, growth and longevity in two freshwater turtles, Emys orbicularis and Mauremys rivulata, from Mediterranean Turkey (Reptilia: Testudines)

Mon, 30 Jan 2017 12:05:45

We estimated growth parameters of Emys orbicularis and Mauremys rivulata in Mediterranean Turkey with the skeletochronological method, using specimens drowned in fyke nets. In adult E. orbicularis, the median age was 8 years in males and 10 years in females. The median age of adult M. rivulata was 10 years for both sexes. Both species reach sexual maturity at an age of 5-7 years. No difference was found in age composition between the sexes.

European Red List of Habitat: Part 2 - Terrestrial and freshwater habitat (2016)

Fri, 20 Jan 2017 11:56:20

The first ever European Red List of Habitats reviews the current status of all natural and semi-natural terrestrial, freshwater and marine habitats and highlights the pressures they face. Using a modified version of the IUCN Red List of Ecosystems categories and criteria, it covers the EU28, plus Iceland, Norway, Switzerland and the Balkan countries and their neighbouring seas. Over 230 terrestrial and freshwater habitats were assessed. The Red List complements the data collected on Annex I habitat types through Article 17 reporting as it covers a much wider set of habitats than those legally protected under the Habitats Directive. The European Red List of Habitats provides an entirely new and all embracing tool to review commitments for environmental protection and restoration within the EU2020 Biodiversity Strategy. In addition to the assessment of threat, a unique set of information underlies the Red List for every habitat: from a full description to distribution maps, images, links to other classification systems, details of occurrence and trends in each country and lists of threats with information on restoration potential.

Adaptation des grilles DCE de qualité nutriments et phytoplancton (abondance et biomasse) pour les lagunes oligo et mésohalines (2016)

Wed, 16 Nov 2016 17:07:39

L’objectif général de ce travail est d’adapter les grilles DCE de qualité nutriments et phytoplancton (abondance et biomasse) pour les lagunes oligo et mésohalines méditerranéennes. Par la position intermédiaire entre les eaux marines et continentales (douces) la recherche d’indicateurs pour les lagunes oligo et mésohalines peut contribuer à assurer la continuité eaux douces/eaux marines dans l’application de DCE. · Sur la base des relations entre EQRPHY et les concentrations en azote total et phosphore total, des seuils de concentrations pour caractériser les lagunes oligo-mésohalines peuvent être proposés. · Les seuils proposés sont sensiblement supérieurs à ceux des lagunes poly-euhalines. Un tel résultat est attendu compte tenu des niveaux trophiques supérieurs dans les lagunes oligo-mésohalines mis en évidence dans la première partie de ce rapport. · La pertinence des seuils proposés doit être étudiée notamment par comparaison avec les valeurs utilisées pour les lacs d’eau douce. Par rapport aux lagunes poly-euhalines, si l’augmentation des seuils pour le bon état paraît logique, celle pour les états dégradés parait plus discutable. La progressivité des seuils pourrait également être analysée dans le contexte des eaux douces.

Pour saluer le Rhône (2016)

Wed, 30 Mar 2016 16:49:48

Rédigé à quatre mains par les géographes Jacques Bethemont et Jean-Paul Bravard, ce beau livre, à la fois scientifique et accessible au grand public, rend hommage à la complexité du plus puissant des fleuves français. Né au fond du Valais en Suisse d’un glacier du même nom, le Rhône est l’un des fleuves les plus puissants d’Europe. Ce n’est pas le plus grand, mais ses 812 km l’emmenant d’un glacier suisse à la Méditerranée sont loin de s’écouler tranquillement. Sa nature, son tracé ainsi que les nombreux travaux d’aménagement qui l’ont métamorphosé depuis plus d’un siècle contribuent à lui donner un statut particulier. Jacques Bethemont et Jean-Paul Bravard partagent ici un ensemble de connaissances issues de leurs recherches menées tout au long de riches carrières placées sous le signe de l’eau. Cette somme porte sur l’ensemble du fleuve et de ses affluents, dans une conception à la fois pluridisciplinaire, actuelle, rétrospective et prospective. Ouvrage de référence pour les acteurs du Rhône, mais aussi pour les curieux, Pour saluer le Rhône donne à voir le fleuve dans son entier.

A revised account of the geographical distribution of the endangered freshwater fish Garra ghorensis in Jordan and implications for conservation

Wed, 17 Apr 2019 10:22:15

Some records of freshwater snail from the Occupied Palestinian territories

Wed, 17 Apr 2019 10:21:22

The life-history traits of widespread freshwater fish species: the case of Roach Rutilus rutilus (Linnaeus, 1758) (Pisces: Teleostei) in water bodies at the southern limits of distribution

Mon, 30 Jan 2017 11:10:07

The Roach Rutilus rutilus (Linnaeus, 1758) (Pisces: Teleostei) is a widespread Eurasian cyprinid freshwater fish. Although numerous studies have investigated the species' life history traits across its main native range of distribution, little is known from water bodies located beyond the southern limits of the latter, especially where the species has been introduced. Between July 2010 and April 2011, a total of 949 R. rutilus specimens was collected from Porsuk Reservoir (NW Turkey), and life-history traits of age, growth, fecundity and egg size were studied and compared to six other R. rutilus populations (including Caspian Roach R. r. caspicus) from the southern limits of distribution. The Porsuk population was characterised by relatively shorter lifespan, slower growth and lower fecundity. These findings support previous studies emphasising the importance of local environmental factors in shaping the life-history traits of widespread fish species. These must be taken into consideration especially in view of the potential value of R. rutilus as an economic resource for in-land fisheries.

Molecular phylogeny and genetic diversity of freshwater anguilla eels in indonesian waters based on mitochondrial sequences

Mon, 30 Jan 2017 11:10:01

Indonesian waters, have been proposed by biologists to be the origin of freshwater eel anguillid. The objective of this study was to investigate molecular phylogenetic relationships and genetic diversity of the seven Indonesian eel taxa based on the cyt b gene. Each eel species was identified by comparison with published sequences, namely Anguilla celebesensis, A. interioris, A. borneensis, A. marmorata, A. bicolor bicolor, A. b. pacifica and A. nebulosa nebulosa. A total of 129 different haplotypes were identified from this study, most of them for the first time, showing haplotype and nucleotide diversities of 0.98 and 4.57 %, respectively. A. bicolor was clearly found to be composed of two subspecies, A. b. bicolor and A. b. pacifica. The first subspecies was split into two major clades supported by a high bootstrap value, with each clade characterized by two diagnostic nucleotides. A. marmorata was also split into two clades, supported by a high bootstrap value. This first study of phylogenetic relationships and genetic diversity from all Anguilla taxa inhabiting Indonesian waters, based on 1115 specimens, is necessary for a local management and conservation of this valuable resource in terms of both biodiversity and economic development.

Www.freshwaterecology.info - An online tool that unifies, standardises and codifies more than 20,000 European freshwater organisms and their ecological preferences

Tue, 16 Jul 2019 14:20:28

How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds

Fri, 8 Jun 2018 12:14:10

Lakes and ponds are scattered on Earth’s surface as islands in the ocean. The organisms inhabiting these ecosystems have thus developed strategies to pass the barrier represented by the surrounding land, to disperse and to colonize new environments. The evidences of a high potential for passive long-range dispersal of organisms producing resting stages inspired the idea that there were no real barriers to their actual dispersal, and that their distribution was only limited by the ecological characteristics of the available habitats. The development of genetic techniques allowed to criticize this view and revealed the existence of a more complex and diverse biological scenario governed by an assortment of historical and ecological factors. In this paper, we review the literature related to the passive dispersal of organisms producing resting stages among inland lentic ecosystems, with special emphasis to temporary ponds, which represent “isolated” ecosystems both in space and in time, and are characterized by high levels of biological diversity. The existence of a sharp decoupling between “dispersal potential” and “actual establishment rates” is stressed, thus urging a definitive overcome of the so-called “Everything is Everywhere” hypothesis in order to gain a proper understanding of the biogeography and ecology of inland water organisms.

Propagule pressure, invasibility of freshwater ecosystems by macrophytes and their ecological impacts: a review of tropical freshwater ecosystems

Tue, 16 Jul 2019 14:26:11

In this review, we aim to draw parallels between the principal concepts of invasion biology, developed mainly for terrestrial plants in temperate regions, with findings for macrophytes recorded in tropical inland waters. In these ecosystems, the most important abiotic and biotic filters influencing invasion success are related to water and sediment conditions, light, disturbance, hydrology and the diversity and density of native species. The main impacts are related to direct and indirect changes in the populations and communities of native macrophytes and other associated organisms. Non-native ecosystem engineer species of macrophytes can affect ecosystems directly, and after affecting ecosystems, their effects can extend to populations and communities. High plant growth rates in the tropics could lead to rapid invasion and larger impacts compared to temperate ecosystems. Although we found many parallels between ecosystems regarding the general concepts of invasion, areas that should receive further investigation in the tropics include (i) the synergistic interaction of multiple invasive species, (ii) the effects of regime shift on invasion success and vice versa and (iii) how climate change will affect the dynamics of macrophyte invasion in tropical ecosystems.

Les zones clés pour la biodiversité d'eau douce dans le hotspot du bassin méditerranéen (2015)

Tue, 16 Jul 2019 14:25:10

Le hotspot (point chaud) de la biodiversité du bassin méditerranéen est bien connu pour l'importance que sa biodiversité revêt à l'échelle mondiale, mais l'importance de la biodiversité d'eau douce n'était pas reconnue précédemment. Dans le cadre de ce projet, les ZCB d'eau douce ont maintenant été identifées, cartographiées et validées dans une grande partie du hotspot méditerranéen. à présent, il est important de faire prendre conscience de leur statut en tant que ZCB d'eau douce validées, et de mettre en place des programmes d'actions de conservation adaptées sur ces sites.

Evaluation multiparamétrique de la qualité de l'eau et biodiversité des macro-invertébrés benthiques de quatre cours d'eau du parc national (réserve de biosphère) de Belezma (Batna, Algérie) (2015)

Wed, 21 Feb 2018 16:25:59

Ce travail a pour objectifs de mettre en évidence la qualité biologique et l’état de santé des eaux courantes du Parc National de Belezma (Réserve de biosphère) à travers une approche multiparamétrique. La biodiversité et les traits de vie des macro-invertébrés benthiques de 4 oueds du Parc (O. Hamla, O. Chaaba, O. Bouilef et O. El Ma) sont analysés en relation avec les facteurs environnementaux : 12 paramètres physico-chimiques de l’eau, caractéristiques globales de l’habitat, degré de pression humaine. La vitesse de l’écoulement de l’eau est généralement très faible à moyenne. Les habitats recensés sont dominés par les galets et les rochers (5 à 90%), les habitats à sable fin et grossier sont peu représentés et ceux à végétation sont totalement absents. L’eau est d’un pH variant entre 7,29 et 8,50, les nitrates et les nitrites ne figurent que par des teneurs infimes. L’eau est douce avec un degré de salinité (0,20% et 0,30%), elle est très faiblement salée et généralement claire (turbidité : 2,8 à 22 NTU). Nous avons recensé un total de 28 taxons de macro invertébrés benthiques répartis en 3 embranchements, 4 classes, 11 ordres et 22 familles différentes. Parmi les insectes, les groupes les plus dominants en nombre sont les diptères (36,85%), les trichoptères (20,92%) ainsi que les éphéméroptères (16,73%). C’est dans l’O. Chaaba où l’on retrouve une biodiversité élevée (richesse totale : 22 taxons ; indice de Shannon : 2,84). Le calcul de l’IBGN montre que la qualité hydrobiologique de l’eau dans les 4 cours d’eau étudiés est globalement qualifiée de moyenne (IBGN entre 9 et 10). Des analyses statistiques faisant appel aux méthodes classiques (CCA : Analyse canonique des corrélations) sont appuyées par des analyses modernes faisant appel aux réseaux de neurones (SOM : Self Organisation Model) sont effectuées afin de décrire les modalités de répartition des populations de macro invertébrés benthiques sous l’influence d’une multitude de facteurs du milieu. / This work aims to highlight the biological quality and health status of flow waters of Belezma National Park (Biosphere Reserve) through a multi-parametric approach. We describe and analyze the biodiversity and life traits of benthic macroinvertebrates of 4 rivers (wadis, Oueds) in the Park (O. Hamla, O. Chaaba, O. Bouilef and O. El Ma) in relation to environmental factors: 12 physicochemical water parameters, global habitat characteristics, degree of human pressure. The velocity of the water flow is generally very low to medium. The habitats are dominated by pebbles and stones (5-90%), fine and coarse sand habitats are poorly represented while plants habitats are completely absent. The water pH is between 7.29 and 8.50, nitrates and nitrites are represented only by trace levels. The water is soft with salinity level (0.20% and 0.30%), it is slightly salted and generally clear (turbidity: 2.8 to 22 NTU). We identified a total of 28 taxa of benthic macroinvertebrates divided into 3 embranchments, 4 classes, 11 orders and 22 different families. Among the insects, the most numerous dominant groups are Diptera (36.85%), Trichoptera (20.92%) and Ephemeroptera (16.73%). High biodiversity (total richness: 22 taxa; Shannon index: 2.84) are noted in O. Chaaba. The evaluated IBGN shows that hydrobiological quality of the water in the 4 streams studied is generally described as ‘’average’’ (IBGN between 9 and 10). Statistical analyzes using conventional methods (CCA: Canonical analysis of correlations) are supported by modern analyzes using the neural networks (SOM: Self Organization Model) are performed to describe the distribution schemes of benthic macro populations under the influence of large environmental factors.

Living Wetland Index - un indice pour mesurer l'état de santé de la biodiversité des milieux humides : son adaptation au bassin méditerranéen (2015)

Wed, 25 Oct 2017 10:51:12

Nous nous sommes intéressés à un milieu riche et fragile, les zones humides d'un des principaux points chauds de biodiversité, le bassin Méditerranéen. Nous nous sommes basés sur le Living Planet Index utilisé en 2011 pour caractériser l'évolution de la biodiversité de ces milieux. Nous avons cherché à corriger les biais déjà identifiés, en ajoutant de nouvelles séries temporelles et en adaptant le jeu de données au cas précis des zones humides. Nous avons également analysé notre jeu de données afin de savoir s'il était représentatif du peuplement complet et réel des vertébrés des zones humides méditerranéennes. Nos résultats démontrent une tendance globale à l'augmentation (60% depuis 1970) mais qui cache une diminution significative et importante des espèces en mauvais état de conservation. Nous montrons également que l'indice actuel nous renseigne surtout sur les espèces des zones humides d'eau douce et permanentes et n'est donc pas représentatif de toute la diversité méditerranéenne./ We were interested in a rich and fragile environnent, wetlands located in a major biodiversity hotspot, the Mediterranean basin. Our study was based on the Living Planet Index used in 2011 to characterize the evolution of biodiversity of these environments. We tried to correct biases previously identified by adding new time series and adapting the data set to the particular case of wetlands. We also analysed our data set to see if it was representative of the entire and real vertebrate species assemblage of Mediterranean wetlands. Our results show an overall increasing trend (60% since 1970) but actually hiding a significant and substantial decrease of threatened species. We also show that the index provides information especially on freshwater and permanents wetlands species and therefore is not representative of the entire Mediterranean wetland divers ity.

Freshwater Key Biodiversity Areas in the Mediterranean Basin Hotspot (2015)

Wed, 14 Jun 2017 15:41:02

Les espèces exotiques envahissantes dans les milieux aquatiques. Connaissances pratiques et expériences de gestion. Vol. 1 Connaissances pratiques (2015)

Mon, 26 Oct 2015 10:02:25

Les espèces exotiques envahissantes dans les milieux aquatiques. Connaissances pratiques et expériences de gestion. Vol. 2 Expériences de gestion (2015)

Mon, 26 Oct 2015 10:02:25

Horizon scanning for invasive alien species with the potential to threaten biodiversity in Great Britain

Tue, 16 Jul 2019 14:24:49

Invasive alien species (IAS) are considered one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change. Horizon scanning, the systematic examination of future potential threats and opportunities, leading to prioritization of IAS threats is seen as an essential component of IAS management. Our aim was to consider IAS that were likely to impact on native biodiversity but were not yet established in the wild in Great Britain. To achieve this, we developed an approach which coupled consensus methods (which have previously been used for collaboratively identifying priorities in other contexts) with rapid risk assessment. The process involved two distinct phases: Preliminary consultation with experts within five groups (plants, terrestrial invertebrates, freshwater invertebrates, vertebrates and marine species) to derive ranked lists of potential IAS. Consensus-building across expert groups to compile and rank the entire list of potential IAS. Five hundred and ninety-one species not native to Great Britain were considered. Ninety-three of these species were agreed to constitute at least a medium risk (based on score and consensus) with respect to them arriving, establishing and posing a threat to native biodiversity. The quagga mussel, Dreissena rostriformis bugensis, received maximum scores for risk of arrival, establishment and impact; following discussions the unanimous consensus was to rank it in the top position. A further 29 species were considered to constitute a high risk and were grouped according to their ranked risk. The remaining 63 species were considered as medium risk, and included in an unranked long list. The information collated through this novel extension of the consensus method for horizon scanning provides evidence for underpinning and prioritizing management both for the species and, perhaps more importantly, their pathways of arrival. Although our study focused on Great Britain, we suggest that the methods adopted are applicable globally.

Speciation in Freshwater Fishes

Thu, 15 Feb 2018 17:18:55

The extraordinary species richness of freshwater fishes has attracted much research on mechanisms and modes of speciation. We here review research on speciation in freshwater fishes in light of speciation theory, and place this in a context of broad-scale diversity patterns in freshwater fishes. We discuss several major repeated themes in freshwater fish speciation and the speciation mechanisms they are frequently associated with. These include transitions between marine and freshwater habitats, transitions between discrete freshwater habitats, and ecological transitions within habitats, as well as speciation without distinct niche shifts. Major research directions in the years to come include understanding the transition from extrinsic environment-dependent to intrinsic reproductive isolation and its influences on species persistence and understanding the extrinsic and intrinsic constraints to speciation and how these relate to broad-scale diversification patterns through time.

Biological and chemical responses in a temporarily open/closed estuary to variable freshwater inputs

Fri, 8 Jun 2018 12:08:54

In coastal lagoons with occasional connection to oceans, variations in physicochemical conditions and biological responses can be pronounced. To examine the influence of variable rainfall and tidal flushing, we measured, over a 4-year period, salinity, temperature and dissolved oxygen, and fish abundances, in Devereux Slough, a coastal lagoon occasionally connected to the Pacific Ocean along the California coast. We test the hypotheses that salinity is the primary influence on fish composition, and that fish density is affected by freshwater discharge and by berm breaches. During our sampled years, annual rainfall varied from 188 to 971 mm, and the sand berm separating the Slough from the ocean breached in each year except 2007, a drought period. Average yearly salinity ranged from 7.7 to 37.1 ppt. Hypoxic conditions in the near-bottom water were common each year. The best predictor of the fish composition was salinity, and an indirect correlation with fresh water discharge was responsible for much of the temporal variation in the fish assemblage. The interaction between salinity, state of the estuary mouth (open vs. closed), and precipitation significantly predicted densities of Fundulus parvipinnis (Girard 1984).

Modelling Community Structure in Freshwater Ecosystems (2014)

Wed, 15 Feb 2023 10:50:09

This volume presents approaches and methodologies for predicting the structure and diversity of key aquatic communities (namely, diatoms, benthic macroinvertebrates and fish), under natural conditions and under man-made disturbance. The intent is to offer an organized means for modeling, evaluating and restoring freshwater ecosystems.

Comparative assessment of the vulnerability and resilience of deltas (2014)

Fri, 25 Feb 2022 18:09:00

Sept siècles d'histoire hydroclimatique du Rhône d'Orange à la mer (1300-2000) (2014)

Mon, 22 Oct 2018 16:52:13

Ce numéro hors-série de la revue Méditerranée est consacré à l’histoire hydroclimatique de la basse vallée du Rhône depuis le milieu du bas Moyen Âge (1300-2000). L’étude hydrologique repose sur un millier d’événements (crues, étiages, glaces fluviales) qui mettent en valeur la violence de huit crises périodiques durant la période du Petit Âge Glaciaire. La première partie est consacrée à la dynamique fluviale à travers les inondations et les métamorphoses des lits fluviaux d’après les cartes anciennes. La deuxième partie étudie les pluies et les sécheresses, avec invasions de sauterelles et étiages exceptionnels, comme celui de 1639. Les grands hivers avec glaces flottantes et arrêtées y font également l’objet d’une étude statistique. Enfin, la troisième partie traite, par l’approche monographique, d’une dizaine d’événements hydroclimatiques extrêmes depuis le XVIe siècle dont l’étude s’en trouve ainsi renouvelée, notamment pour la crue centennale de 1856.

The status and distribution of freshwater biodiversity in the Eastern Mediterranean (2014)

Fri, 9 Jun 2017 16:43:22

This IUCN report and accompanying dataset on the status and distribution of freshwater biodiversity in the Eastern Mediterranean, and the associated report and data on the Freshwater Key Biodiversity Areas in the wider Mediterranean Basin represent major advances in provision of information to help incorporate biodiversity needs into water development planning processes within an Integrated River Basin Management framework.Nineteen per cent of all freshwater species assessed here are globally threatened. However, when only those species that are endemic to the region are considered (species which, if lost from the region, will become globally extinct) this level of threat rises to 58.2%. The highest number of threatened species are found within six distinct areas within the region: the coastal Levant and Gulf of İskenderun catchments from the Orontes to the Litani and the Upper Hula basin and Lake Kinneret/Sea of Galilee, the widerTigris and Euphrates lower plains including the Hawizah marshes up to the Diyala River in Iraq and lower Karoun in Iran, the Khabur River including the Ras al-Ain springs (Euphrates catchment) in northern Syria, the Lakes Region of Turkey (including the upper Büyük Menderes, the Köprü River, and Kırkgöz Springs), the lower Çoruh River and otherBlack Sea catchments in north-eastern Turkey, and the lower Aras/Kura River in Azerbaijan and southern Armenia This publication includes an executive summary in English, Turkish, Arabic.

Abondance et composition du phytoplancton sur les lagunes méditerranéennes oligo et mésohalines (2014)

Wed, 16 Nov 2016 17:07:32

Dans le cadre de la mise en oeuvre de la DCE sur les lagunes méditerranéennes, des travaux ont été menés depuis 2010 par Ifremer, la Tour du Valat et l’IRSTEA (financements Onema et AERM&C), visant à évaluer la pertinence des indicateurs macrophytes et macrofaune pour les lagunes oligohalines et mésohalines (salinité moyenne < 18 PSU). La question de la pertinence des métriques et seuils de l’indicateur de l’élément de qualité biologique « phytoplancton » de pose également, en particulier du fait du caractère particulièrement confiné des lagunes oligo-mésohalines. L’objectif de cette étude est de caractériser l’abondance et la composition phytoplanctonique de 5 lagunes oligo et mésohalines de la façade méditerranéenne française (Scamandre, Crey, Charnier, Bolmon et Grand-Palun). Les analyses des pigments accessoires (chlorophylliens et xanthophylles) mettent en évidence des profils de composition phytoplanctonique distincts en rapport avec les niveaux de biomasse phytoplanctonique totale observés dans les cinq lagunes. La lagune de la Grande Palun, caractérisée par une biomasse phytoplanctonique modérée, présente une diversité pigmentaire forte, avec une contribution similaire des différents groupes phytoplanctoniques identifiés. Les lagunes du complexe Scamandre-Crey-Charnier, caractérisées par des biomasses phytoplanctoniques fortes et la dominance du nanophytoplancton (Scamandre et Crey) ou du picophytoplancton (Charnier), présentent majoritairement des espèces de la lignée brune et des cyanobactéries. Enfin, la lagune de Bolmon, caractérisée par une très forte biomasse phytoplanctonique et la dominance du picophytoplancton, se distinguer par l’importance des espèces de la lignée verte (Chlorophytes et Prasinophytes) et la présence possible de cyanobactéries. Les grilles actuelles du phytoplancton et de la physico-chimie de l’eau ont été développées et consolidées sur un jeu de données de lagunes poly-euhalines. Les seuils demandent à être consolidés pour l’ensemble des lagunes oligo-mésohalines, en prenant en compte les particularités hydromorphologiques et les pressions pesant sur ces écosystèmes (confinement, faible profondeur, fort stock sédimentaire, apports continus par des canaux,…).

The World's Water Volume 8. The Biennal Report on Freshwater Resources. (2014)

Mon, 26 Oct 2015 10:02:32

Les poissons d'eau douce à l'heure du changement climatique : état des lieux et pistes pour l'adaptation (2014)

Mon, 26 Oct 2015 10:02:28

Freshwater biodiversity and conservation in mediterranean climate streams of Chile

Fri, 8 Jun 2018 12:16:21

In Chile, mediterranean climate conditions only occur in the Central Zone (ChMZ). Despite its small area, this mediterranean climate region (med-region) has been recognised as a hotspot for biodiversity. However, in contrast to the rivers of other med-regions, the rivers in the ChMZ have been studied infrequently, and knowledge of their freshwater biodiversity is scarce and fragmented. We gathered information on the freshwater biodiversity of ChMZ, and present a review of the current knowledge of the principal floral and faunal groups. Existing knowledge indicates that the ChMZ has high levels of endemism, with many primitive species being of Gondwanan origin. Although detailed information is available on most floral groups, most faunal groups remain poorly known. In addition, numerous rivers in the ChMZ remain completely unexplored. Taxonomic specialists are scarce, and the information available on freshwater biodiversity has resulted from studies with objectives that did not directly address biodiversity issues. Research funding in this med-region has a strong applied character and is not focused on the knowledge of natural systems and their biodiversity. Species conservation policies are urgently required in this highly diverse med-region, which is also the most severely impacted and most populated region of the country.

Gap analysis revealed a low efficiency of Natura 2000 network for the conservation of endemic species in Mediterranean temporary freshwater habitats

Tue, 16 Jul 2019 14:19:29

Listed and rare species are abundant in temporary freshwater habitats. Among them, the endemic contingent represents a crucial conservation target particularly in the areas characterized by abundant endemic flora for which the local administrations have a high level of responsibility. The aim of this research was to test how the endemic plants found in Mediterranean temporary ponds were represented in Natura 2000 network in a biodiversity hotspot of the Mediterranean region. The results of our research at regional scale pointed out that the existing Nature 2000 sites provide a limited degree of protection and that the gap analysis should be taken into account when conservation priorities are set.

Workbook for Managing Urban Wetlands in Australia (2013)

Mon, 5 Feb 2018 13:35:57

Section 1 - People, Politics and Wetlands Section 2 - Freshwater Wetlands: Ecology, Rehabilitation and Management Section 3 - Estuarine Wetlands: Ecology, Rehabilitation and Management Section 4 - Monitoring Wetlands Section 5 - Guidelines for preparing a Wetland Plan of Management

Distribution and reproduction of Procarambus clarkii in relation to water management, salinity and habitat type in the Camargue (2013)

Mon, 26 Oct 2015 10:02:35

Watershed land use types as drivers of freshwater phytoplankton structure

Fri, 8 Jun 2018 12:05:12

The potential importance of watershed land use types, lake/watershed morphometry/topography and geographic distance as drivers of phytoplankton community composition was evaluated by using data collected from 18 freshwaters (lakes and reservoirs) distributed around Greece. In all freshwaters, phytoplankton species composition showed a strong correlation with the composition of land uses within their watersheds but no correlation with morphometry/topography and geographic distance. Cyanobacteria were found to be associated with artificial and agricultural land use types. Chrysophytes were closely associated to forested areas whereas euglenophytes to industrial, commercial, and transport units. Phytoplankton total biomass was significantly higher in freshwaters with a cover of agricultural and artificial land use >30% in their watersheds. This rather low threshold of agricultural and artificial land use cover might be indicative of the higher sensitivity of Mediterranean freshwaters to eutrophication process. Analysis performed separately for lakes and reservoirs revealed some diverse patterns with lake morphometric/topographic variables significantly affecting similarity in species occurrence. The results demonstrate that land use types reflecting anthropogenic pressures could act as critical drivers explaining phytoplankton structure. Our research suggests that Mediterranean freshwaters could be highly sensitive to land use types within their watersheds, thus landscape structure and configuration should be taken into account toward effective conservation and management plans.

Drivers and stressors of freshwater biodiversity patterns across different ecosystems and scales: a review

Fri, 8 Jun 2018 14:50:51

The present review with focus on the last decade (2000–2010) aims to (i) collecting the major hypotheses explaining freshwater biodiversity patterns, (ii) identifying the main stressors affecting freshwater biodiversity, and (iii) revealing information gaps regarding ecosystem types, organism groups, spatial and temporal scales to highlight research needs to better propose sound conservation measures. The comparative analysis addresses six organism groups ranging from microorganisms to fish in basins, rivers, lakes, wetlands, ponds and groundwater. Short-term studies at ecoregion and catchment scale focusing on invertebrates, macrophytes and fish in Palaearctic and Nearctic regions dominated. The most frequent hypotheses tested were the landscape filter concept, the species–area relationship, the metacommunity concept. Dominating natural drivers were area, heterogeneity and disturbance. Land use, eutrophication and habitat destruction were identified as most important stressors. Generally, freshwater biodiversity declined in response to these stressors in contrast to increasing biodiversity determined by natural drivers across all ecosystems. Preferred organism groups were fish and invertebrates, most frequently studied in rivers, in contrast to smaller organisms (e.g. bacteria) and, e.g. groundwater being underrepresented. Hypotheses originating from the last century are still tested in freshwater research, while novel concepts are either missing or untested. Protection of freshwater biodiversity is the ultimate challenge since it supports valuable ecosystems services ensuring perpetuation of mankind. For that, comprehensive large-scale studies with holistic approaches are urgently needed.

The lower Danube (2012)

Mon, 26 Oct 2015 10:09:27

Habitat residence during continental life of the European eel Anguilla anguilla investigated using linear discriminant analysis applied to otolith Sr:Ca ratios (2012)

Mon, 26 Oct 2015 10:03:44

Selective consequences of catastrophes for growth rates in a stream-dwelling salmonid (2012)

Mon, 26 Oct 2015 10:02:36

Le Rhône aval en 21 questions (2012)

Mon, 26 Oct 2015 10:02:35

Processus et dynamique de la recolonisation et de la biodiversité dans les bras du Rhin et autres cours d'eau restaurés de la Plaine d'Alsace après reconnexion (2012)

Mon, 26 Oct 2015 10:02:34

Threatening processes and conservation management of endemic freshwater fish in the Mediterranean Basin: a review

Tue, 16 Jul 2019 14:09:05

Mediterranean endemic freshwater fish are among the most threatened biota in the world. The Mediterranean basin has experienced substantial reductions in precipitation and water availability, which will worsen with climate change. Current water policy is directed to increase water-supply demands, especially for agriculture, and not to improve water-use efficiency and implement integrated and sustainable water management. Illegal extractions are common, exacerbating problems for important protected areas. Management is needed to mitigate the conflicts between environmental water and human demand, and ensure availability of water to maintain ecological processes and Mediterranean freshwater biodiversity. Water availability is not the only threat, although it is exacerbated by pollution and invasive species. The uneven spatial distribution of threats across the Mediterranean basin requires different strategies to conserve freshwater biodiversity. Implementation of multi-national laws (e.g. Water Framework Directive in the European Union) will help future management of freshwater ecosystems. Management actions must be planned at whole-catchment scales, with collaboration among different countries and water-management authorities. The current reserve area is small compared with other areas in the world and driven by terrestrial interests, and should be evaluated for its effectiveness to protect the Mediterranean freshwater biodiversity.

The diversity of life in African freshwaters: underwater, under threat (2011)

Mon, 21 Aug 2017 09:47:52

In the most comprehensive assessment of its kind, 4,989 African freshwater species were assessed by close to 200 scientists over a six year period for the IUCN Red List of Threatened Species, including all described species of freshwater fish, molluscs, crabs, dragonflies and damselflies, and selected families of aquatic plants. The findings from this new study give us a unique opportunity to try to influence developers and governments when they are planning freshwater infrastructure projects, which are still in their early stages in most of Africa.

European Red List of non-marine molluscs (2011)

Mon, 26 Oct 2015 10:10:27

European Red List of freshwater fishes (2011)

Mon, 26 Oct 2015 10:09:55

Eléments de connaissance pour la gestion du transport solide en rivière (2011)

Mon, 26 Oct 2015 10:08:54

Density-dependent and inter-specific interactions affecting European eel settlement in freshwater habitats (2011)

Mon, 26 Oct 2015 10:06:47

Famille des Centrarchidae. In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:25

La perche soleil (Lepomis gibbosus Linnaeus, 1758). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:25

Ordre des Gasterosteiformes. Famille des Gasterosteidae. In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:02

L'épinoche (Gasterosteus gymnurus Cuvier, 1729). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:01

Famille des Poecilidae. La gambusie (Gambusia holbrooki Girard, 1859). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:01

La grémille (Gymnocephalus cernuus Linnaeus, 1758). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:06:01

Assessment of riparian forest vegetation of rivers supporting the Prespa trout in the Transboundary Prespa Park (2011)

Mon, 26 Oct 2015 10:04:31

La carpe commune (Cyprinus carpio Linnaeus, 1758). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:04:24

Le mulet à grosse tête (Mugil cephalus Linnaeus, 1758). In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:04:24

Orde des Mugiliformes. Famille des Mugilidae. In: Les poissons d'eau douce de France. KEITH P., PERSAT H., FEUNTEUN E. & ALLARDI J. (2011)

Mon, 26 Oct 2015 10:04:24

Innocent until proven guilty? Stable coexistence of alien rainbow trout and native marble trout in a Slovenian stream (2011)

Mon, 26 Oct 2015 10:02:47

Spatial dynamics and morphological plasticity of common reed (Phragmites australis) and cattails (Typha sp.) in freshwater marshes and roadside ditches

Tue, 16 Jul 2019 14:26:02

Over the last decades, the abundance of common reed has significantly increased in freshwater wetlands of eastern North America, and stands of this species are now commonly alternating with stands of cattails. Since these species share many characteristics, the contact zone between common reed and cattail stands may witness strong interspecific interactions. We surveyed stand dynamics in roadside ditches and freshwater marshes at these contact zones over three years, and we examined the morphological plasticity in response to neighbors. Results indicate that common reed is clearly gaining ground over time, while cattails stands are retreating. We also found annual variability in the spatial dynamics, suggesting that other factors, such as the effect of weather conditions on water level, may affect population processes. Interspecific interactions had a detrimental effect on both common reed and cattail biomass. However, common reed showed morphological plasticity in shoot height, number of nodes, and internodes length, while cattails did not. Our observations suggest that common reed has a net competitive advantage over cattails in roadside ditches and freshwater marshes.

Ecologie de la restauration et ingiénierie écologique. Enjeux, convergences, applications (2010)

Mon, 26 Oct 2015 10:10:08

Restoration of lakes, streams, floodplains, and bogs in Europe. Principles and case studies (2010)

Mon, 26 Oct 2015 10:10:07

The status and distribution of freshwater biodiversity in Northern Africa (2010)

Mon, 26 Oct 2015 10:09:52

Colonisation d'un écosystème d'eau douce hétérogène par un oiseau d'eau herbivore: le cygne tuberculé (Cygnus olor) dans les étangs piscicoles de Dombes (2010)

Mon, 26 Oct 2015 10:09:51

Manuel de gestion des plantes exotiques envahissant les milieux aquatiques et les berges du bassin Loire-Bretagne (2010)

Mon, 26 Oct 2015 10:09:33

Climate change impacts on freshwater ecosystems (2010)

Mon, 26 Oct 2015 10:09:12

Carrières, biodiversité et fonctionnement des hydrosystèmes (2010)

Mon, 26 Oct 2015 10:09:01

Fresh water. The essence of life (2010)

Mon, 26 Oct 2015 10:08:39

Gestion durable et équitable de l'eau douce en Méditerranée. Mémoire et traditions, avenir et solutions. Actes (2010)

Mon, 26 Oct 2015 10:08:07

Hydrodynamique de l'environnement (2010)

Mon, 26 Oct 2015 10:07:37

Lower Jordan River Rehabilitation Project. Transboundary Diagnostic Analysis (TDA), Jordan (2010)

Mon, 26 Oct 2015 10:07:14

Temporal variability of carbon recycling in coastal sediments influenced by rivers: assessing the impact of flood inputs in the Rhône River prodelta (2010)

Mon, 26 Oct 2015 10:06:24

Nuclear and mitochondrial DNA sequence data reveal the evolutionary history of Barbus (Cyprinidae) in the ancient lake systems of the Balkans (2010)

Mon, 26 Oct 2015 10:04:09

Status and distribution of aquatic plants. In: The status and distribution of freshwater biodiversity in Northern Africa. GARCIA N., CUTELLOD A. & ABDUL MALEK A. (2010)

Mon, 26 Oct 2015 10:03:27

Dietary breadth and trophic position of introduced European catfish Silurus glanis in the River Tarn (Garonne River basin), southwest France (2010)

Mon, 26 Oct 2015 10:03:02

Detection of density-dependent growth at two spatial scales in marble trout (Salmo marmoratus) populations (2010)

Mon, 26 Oct 2015 10:02:47

Individual growth and its implications for the recruitment dynamics of stream-dwelling marble trout (Salmo marmoratus) (2010)

Mon, 26 Oct 2015 10:02:47

The management of small, isolated salmonid populations: do we have to fix it if it ai'nt broken? (2010)

Mon, 26 Oct 2015 10:02:47

Biodiversity loss and the global water crisis. A fact book on the links between biodiversity and water security (2010)

Mon, 26 Oct 2015 10:02:42

Comparative assessment of the vulnerability resilience of 10 deltas. Synthesis report. (2010)

Mon, 26 Oct 2015 10:02:26

Élements d'hydromorphologie fluviale (2010)

Mon, 26 Oct 2015 10:02:25

Freshwater diatom and macroinvertebrate diversity of coastal permanent ponds along a gradient of human impact in a Mediterranean eco-region

Fri, 8 Jun 2018 14:52:01

Mediterranean coastal areas are characterised by heavily transformed landscapes and an ever-increasing number of ponds are subjected to strong alterations. Although benthic diatoms and macroinvertebrates are widely used as indicators in freshwater ecosystems, little is still known about the diatom communities of lowland freshwater ponds in the Mediterranean region, and, furthermore, there are few macroinvertebrate-based methods to assess their ecological quality, especially in Italy. This article undertakes an analysis of benthic diatom and macroinvertebrate communities of permanent freshwater ponds, selected along a gradient of anthropogenic pressures, to identify community indicators (taxa and/or metrics) useful to evaluate the effect of human impacts. A series of 21 ponds were sampled along Tyrrhenian coast in central Italy. Five of these ponds, in a good conservations status and surrounded by woodland were selected as 'reference sites' for macroinvertebrates and epipelic diatoms. The remaining sixteen ponds were located in an agricultural landscape subject to different levels of human impact. The total number of macroinvertebrate taxa found in each pond was significantly higher in reference sites than in both the intermediate and heavily degraded ones, whereas the diatom species richness did not result in a good community variable to evaluate the pond ecological quality. The analysis revealed a substantial difference among the compositions of diatom communities between reference ponds and degraded ponds. The former were characterised by the presence of several species belonging to genera, such as Pinnularia sp., Eunotia sp., Stauroneis sp., Neidium sp., all of which were mostly absent from degraded ponds. Furthermore, the taxonomic richnesses of some macroinvetebrate groups (Odonata, Ephemeroptera, Trichoptera, Coleoptera), and taxa composition attributes of macroinvertebrate communities (total abundance, percentages of top three dominant taxa, percentages of Pleidae, Ancylidae, Hirudinea, Hydracarina) significantly correlated with variables linked with anthropogenic pressures. The results of the investigation suggested that diatoms tended more to reflect water chemistry through changes in community structure, whereas invertebrates responded to physical habitat changes primarily through changes in taxonomic richness. The methodologies developed for the analysis of freshwater benthic diatom and macroinvertebrate communities may have a considerable potential as a tool for assessing the ecological status of this type of water body, complying with the European Union Water Framework Directive 2000/60/EC.

Larval digeneans of mammals in freshwater invertebrates as intermediate hosts

Wed, 12 Jun 2019 11:15:54

In the majority of digeneans infecting Insectivora, the larval stages are found in snails (cercaria) and terrestrial or aquatic invertebrates (metacerearia) The diets of both the Pyrenean desman Galemys pyrenaicus (Talpidae) and aquatic shrews (genus Neomys) include a wide variety of aquatic invertebrates that can acts as the second intermediate host of several species of digeneans. In 2004, sampling was performed in the Py Natural Reserve (French Pyrenees) A total of 912 Bythinella refescens (first intermediate host) and 167 non-mollusuc acquatic invertebrates (second intermediate hosts) were studied for the detection of larval stages of digenans Two species of digenean trematodes were recovered as cercariae and metacercariac. These two species were Pseudocephalotrema pyrenaica (Lecithodendriidae) and Skrjabinophusetus neomydis (Nanophyetidae). In snails their general prevalence was 20.4% and 1.97% respectively In the second intermediate hosts the corresponding prevalence rates were 22.15% and 3%, respectively. The study of larval digenenans of invertebrates can be used to detect the presence of small mammals.

Are dabbling ducks major players or merely noise in freshwater ecosystems? A European perspective, with references to population limitation and density dependence

Thu, 31 Aug 2017 13:37:38

Waterfowl ecologists consider ducks important players in patterns and processes of freshwater ecosystems. Limnologists and Fish biologists, on the other hand, historically have "a bottom-up" view of the same systems, often regarding waterbirds as "background noise" compared to other biotic influences. Evidence for and against these largely opposing views is reviewed, focussing on European dabbling duck studies. In oligo- and mesotrophic wetlands at low breeding density, their role is likely to be overshadowed by biotic interactions between fish, invertebrates and plants. Conversely, many other freshwater systems may be affected by dabbling ducks in various ways, acting as dispersers of invertebrates and plants, as predators, and as eutrophicators. It is concluded that dabbling ducks, affect freshwater systems more profoundly than has hitherto been acknowledged. In their turn, freshwater ecosystems affect the ducks' population ecology. In a less comprehensive treatment, the evidence for the major paradigms addressing population limitation in dabbling ducks is discussed briefly from a European perspective. It is concluded that top-down (predation) as well as bottom-up (food limitation) processes may both affect population size, but evidence for either is correlative, necessitating more experimental Studies based on explicit predictions from pattern-oriented studies. In a discussion of the prospects for adopting a more adaptive management approach for European dabbling ducks, it is argued that a lack of information about annual variation in recruitment and harvest rates are major obstacles to understanding population change and for adopting a more adaptive management. A compilation of European studies about density dependence in Mallard Anas platyrhynchos indicates that population regulation may be a common phenomenon in this species, with possible important ramifications for research as well as management programmes.

Prespa au coeur des Balkans. Une histoire naturelle et humaine (2009)

Mon, 26 Oct 2015 10:10:46

Guidelines pour la conduite d'un diagnostic pour l'aménagement et la gestion d'une zone humide: cas du complexe du Bas Loukkos (Maroc) (2009)

Mon, 26 Oct 2015 10:10:26

L'eau douce en France: histoire d'un long combat (2009)

Mon, 26 Oct 2015 10:09:01

The wetlands handbook (2009)

Mon, 26 Oct 2015 10:08:54

Le golfe du Lion. Un observatoire de l'environnement méditerranéen (2009)

Mon, 26 Oct 2015 10:08:38

Keeping rivers alive. A primer on environmental flows (2009)

Mon, 26 Oct 2015 10:08:27

Des rivières et des hommes en Provence-Alpes-Côte d'Azur (2009)

Mon, 26 Oct 2015 10:08:07

Le réseau des rivières sauvages. Etude de préfiguration (2009)

Mon, 26 Oct 2015 10:06:28

Truite aux oeufs d'or et rivière d'émeraude: enjeux et conflits potentiels autour de la pêche sportive dans la vallée de la Soca. In: Vie locale, ruralité, tourisme et paysages dans l'aire méditerranéo-alpine. Regards croisés franco-slovènes sur la durabilité. BARTHES A. & SANDOZ A. (2009)

Mon, 26 Oct 2015 10:04:12

Le retour attendu de la loutre dans les zones humides du littoral méditerranéen (2009)

Mon, 26 Oct 2015 10:04:07

The Rhone River Basin. In: Rivers of Europe. TOCKNER K., UEHLINGER U. & ROBINSON C.T. (2009)

Mon, 26 Oct 2015 10:03:47

Apports sédimentaires du Rhône à la mer. Variabilités séculaires et impacts des aménagements. In: Le golfe du Lion. Un observatoire de l'environnement en Méditerranée. MONACO A., LUDWIG W., PROVANSAL M. & PICON B. (2009)

Mon, 26 Oct 2015 10:03:32

Reappraisal and range extension of non-indigenous Mysidae (Crustacea, Mysida) in continental and coastal waters of eastern France (2009)

Mon, 26 Oct 2015 10:02:40

Retour aux sources: l'aventure des poissons migrateurs (2008)

Mon, 26 Oct 2015 10:11:40

Sustainable riparian zones. A management guide (2008)

Mon, 26 Oct 2015 10:11:25

Le Rhône en 100 questions (2008)

Mon, 26 Oct 2015 10:10:57

Plantes aquatiques d'eau douce: biologie, écologie et gestion (2008)

Mon, 26 Oct 2015 10:09:33

Rivers and riverine woodlands. Calm waterways and their shady banks (2008)

Mon, 26 Oct 2015 10:08:40

Conservation biology of freshwater turtles and tortoises. A compilation project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group (2008)

Mon, 26 Oct 2015 10:08:06

Wadi hydrology (2008)

Mon, 26 Oct 2015 10:07:53

Pourquoi les crues de la décennie 1993-2003 ont-elles touché surtout la Rhône aval et la Camargue? In: Le Rhône en 100 questions. BRAVARD J.P. & CLEMENS A. (2008)

Mon, 26 Oct 2015 10:06:22

Fauna i endring-spredning av dyr med eksempler fra ferskvann i Vest-Norge = Fauna changes induced by man. Examples from freshwater in south-west Norway (2008)

Mon, 26 Oct 2015 10:05:32

Macrofaunal density, biomass and composition of estuarine sediments and their relationship to the river plume of the Rhone River (NW Mediterranean) (2008)

Mon, 26 Oct 2015 10:04:58

TIMS measurements of 226Ra and 228Ra in the Gulf of Lion, an attempt to quantify submarine groundwater discharge (2008)

Mon, 26 Oct 2015 10:03:47

Poly-aromatic hydrocarbon (PAH) inputs from the Rhône River to the Mediterranean Sea in relation with the hydrological cycle: impact of floods (2008)

Mon, 26 Oct 2015 10:03:11

Dispersal of freshwater invertebrates by large terrestrial mammals: a case study with wild boar (Sus scrofa) in Mediterranean wetlands (2008)

Mon, 26 Oct 2015 10:02:49

Potential factors controlling the population viability of newly introduced endangered marble trout populations (2008)

Mon, 26 Oct 2015 10:02:47

The role of density-dependent individual growth in the persistence of freshwater salmonid populations (2008)

Mon, 26 Oct 2015 10:02:47

Total population density during the first year of life as a major determinant of lifetime body-length trajectory in marble trout (2008)

Mon, 26 Oct 2015 10:02:47

Avenir du fleuve Niger (2007)

Thu, 28 Apr 2022 10:44:53

Global diversity of aquatic macrophytes in freshwater (January 1, 2007)

Tue, 16 Jul 2019 14:24:31

Aquatic macrophytes are aquatic photosynthetic organisms, large enough to see with the naked eye, that actively grow permanently or periodically submerged below, floating on, or growing up through the water surface. Aquatic macrophytes are represented in seven plant divisions: Cyanobacteria, Chlorophyta, Rhodophyta, Xanthophyta, Bryophyta, Pteridophyta and Spermatophyta. Species composition and distribution of aquatic macrophytes in the more primitive divisions are less well known than for the vascular macrophytes (Pteridophyta and Spermatophyta), which are represented by 33 orders and 88 families with about 2,614 species in c. 412 genera. These c. 2,614 aquatic species of Pteridophyta and Spermatophyta evolved from land plants and represent only a small fraction (∼1%) of the total number of vascular plants. Our analysis of the numbers and distribution of vascular macrophytes showed that whilst many species have broad ranges, species diversity is highest in the Neotropics, intermediate in the Oriental, Nearctic and Afrotropics, lower in the Palearctic and Australasia, lower again in the Pacific Oceanic Islands, and lowest in the Antarctic region. About 39% of the c. 412 genera containing aquatic vascular macrophytes are endemic to a single biogeographic region, with 61–64% of all aquatic vascular plant species found in the Afrotropics and Neotropics being endemic to those regions. Aquatic macrophytes play an important role in the structure and function of aquatic ecosystems and certain macrophyte species (e.g., rice) are cultivated for human consumption, yet several of the worst invasive weeds in the world are aquatic plants. Many of the threats to fresh waters (e.g., climate change, eutrophication) will result in reduced macrophyte diversity and will, in turn, threaten the faunal diversity of aquatic ecosystems and favour the establishment of exotic species, at the expense of native species.

Inventory of Bulgarian wetlands and their biodiversity. Part 1: Non-lotic wetlands (2007)

Mon, 26 Oct 2015 10:08:41

Les ruisseaux de la source à la rivière (2007)

Mon, 26 Oct 2015 10:06:51

Climate change impacts on structure and diversity of fish communities in rivers (2007)

Mon, 26 Oct 2015 10:05:58

Les anciens bras fluviaux: lones, boires, noues (2007)

Mon, 26 Oct 2015 10:05:36

Hybridization mechanisms between the endangered marble trout (Salmo marmoratus) and the brown trout (Salmo trutta) as revealed by in-stream experiments (2007)

Mon, 26 Oct 2015 10:04:01

Les roselières des fleuves et des lacs (2007)

Mon, 26 Oct 2015 10:03:58

Les forêts alluviales des grands cours d'eau (2007)

Mon, 26 Oct 2015 10:03:35

Long-term changes in river temperature and the influence of climatic and hydrological factors (2007)

Mon, 26 Oct 2015 10:02:43

First ecological observations in French hydro systems of freshwater Polychaeta Hypania Invalida introduced in Western Europe

Mon, 23 Aug 2021 12:34:43

Hypania invalida is a freshwater Polychaeta from the Ponto-Caspian area recently introduced in Western Europe. The aim of this manuscript is to examine its spread in French hydrosystems, to analyse its density in colonised ecosystems and to test the occurrence of a facilitative interaction with Corbicula spp., invasive Bivalvia in many European large rivers. To date H. invalida occurred in the Moselle, the Marne, the Seine, the Rhine and the Rhone Rivers, i.e. the main French hydrosystems. It occurred also in the Meuse River near the border between France and Belgium. The densities observed varied in a broad range and could reach several thousands of individuals by square meter in the channel. At a local scale, the spatial distribution depends on the substrate type constituting the river bottom. In canalised rivers H. invalida reached the highest densities on deposit substrates with an important organic part. When deposit substrates are lacking, H. invalida was aggregated on gravels, pebbles and Corbicula shell bed. The lowest densities were observed on roots and macrophytes. In the Moselle River, the main tributary of the Rhine River, the colonisation was very fast and the resulting densities were the same as in the Belgian Meuse River or in the Rhine River. One year after its introduction on a given site the species can be the prevailing one in term of densities in the channel, with 50% of all collected benthic macro-faunal individuals. No facilitative interaction has been evidenced with Corbicula, some results even indicated that the living molluscs had a negative effect on the Polychaeta. After an explosive demography in the Marne River, the observed densities decreased to a low level varying between several tens and several hundreds of individuals by square meter. These first results suggest that H. invalida has an important ability to spread between hydrosystems but a low competitive value.

First ecological observations in French hydro systems of freshwater Polychaeta Hypania Invalida introduced in Western Europe

Fri, 7 Jun 2019 14:15:53

Diagnostic, aménagement et gestion des rivières : hydraulique et morphologie fluviales appliquèes (2006)

Mon, 26 Oct 2015 10:10:21

Landscape influences on stream habitats and biological assemblages (2006)

Mon, 26 Oct 2015 10:09:26

Gestion stratégique des écosystèmes du fleuve Sénégal. Actions et inactions publiques internationales (2006)

Mon, 26 Oct 2015 10:09:00

Recueil d'expériences du programme Loire Nature 2002-2006 (2006)

Mon, 26 Oct 2015 10:08:57

Chemical warfare in freshwater. Allelopathic effects of macrophytes on phytoplankton (2006)

Mon, 26 Oct 2015 10:08:35

The biology of temporary waters (2006)

Mon, 26 Oct 2015 10:07:19

Timing and rate of sexual maturation of European eel in brackish and freshwater environments (2006)

Mon, 26 Oct 2015 10:06:46

Contribution to the study of coastal rivers and associated prodeltas to sediment supply in Gulf of Lions (NW Mediterranean Sea) (2006)

Mon, 26 Oct 2015 10:06:37

Freshwater biodiversity: importance, threats, status and conservation challenges (2006)

Mon, 26 Oct 2015 10:05:44

Sex differentiation of the European eel in brackish and freshwater environments: a comparative analysis (2006)

Mon, 26 Oct 2015 10:04:01

Freshwaterbiodiversity. Challenges for freshwater biodiversity (2006)

Mon, 26 Oct 2015 10:03:52

The status and distribution of freshwater fish endemic to the Mediterranean Basin (2006)

Mon, 26 Oct 2015 10:02:29

Assessment and provision of environmental flows in Mediterranean watercourses. Concepts, methods and emerging practice (2005)

Mon, 26 Oct 2015 10:11:37

Historical changes in large river fish assemblages of the Americas (2005)

Mon, 26 Oct 2015 10:08:05

Monitoring stream and watershed restoration (2005)

Mon, 26 Oct 2015 10:08:02

Le Niger, une artère vitale. Gestion efficace de l'eau dans le Bassin du Haut Niger (2005)

Mon, 26 Oct 2015 10:07:14

The Niger, a lifeline. Effective management in the Upper Niger Basin (2005)

Mon, 26 Oct 2015 10:07:14

Die Kiesbänke des Tagliamento (Friaul, Italien): ein Lebensraum für Spezialisten im Tierreich (2005)

Mon, 26 Oct 2015 10:04:25

Die herausragende Stellung des Tagliamento (Friaul, Italien) im Europäischen Schutzgebietssystem Natura 2000 (2005)

Mon, 26 Oct 2015 10:03:54

The ephemeral vegetation of seasonal and semi-permanent ponds in tropical West Africa (2005)

Mon, 26 Oct 2015 10:03:54

Modelling the dispersion of radionuclides by a river plume: application to the Rhone River (2005)

Mon, 26 Oct 2015 10:03:40

Geomorphologie, Ökologie und nachhaltiges Management einer Wildflusslandschaft am Beispiel des Fiume Tagliamento: ein Modellökosystem für den Alpenraum und ein Testfall für die EU-Wasserrahmenrichtlinie (2005)

Mon, 26 Oct 2015 10:02:56

Second Discoglossus nigriventer rediscovery expedition in the Central Bekaa Valley, Lebanon (17-28 April 2005 expedition report) (2005)

Mon, 26 Oct 2015 10:02:54

Life-history traits of invasive fish in small Mediterranean streams (2005)

Mon, 26 Oct 2015 10:02:48

Vie et milieu of freshwater diatoms. Comment on current issues in diatom ecology and floristics

Fri, 7 Jun 2019 14:15:52

Some problems arising from the sampling and recording of diatoms from acidic freshwater, epiphytic habitats are discussed. This led to further study of data assemblages recorded from more general low pH sites and suggestions for more definitive clusters of diatoms related to narrow pH ranges. Finally, some brief thoughts on the identification of diatoms and the stability of diatom morphology at the species level.

Freshwater systems of the Great Lakes Basin, Mongolia: opportunities and challenges in the face of climate change (2004)

Mon, 26 Oct 2015 10:11:13

Auswirken des Hitzesommers 2003 auf die Gewässer. Dokumentation (2004)

Mon, 26 Oct 2015 10:10:52

Freshawter fishes in Britain: the species and their distribution (2004)

Mon, 26 Oct 2015 10:10:24

Assessment and provision of environmental flows in Mediterranean watercourses. Concept, methods and emergent practice (2004)

Mon, 26 Oct 2015 10:09:20

Estimation et disposition des débits environnementaux dans les cours d'eau méditerranéens. Concepts, méthodes et pratique émergente (2004)

Mon, 26 Oct 2015 10:09:20

Gestion des plantes exotiques envahissantes (2004)

Mon, 26 Oct 2015 10:08:50

The freshwater fishes of Europe. 8. Part 2: Gobiidae 2 (2004)

Mon, 26 Oct 2015 10:08:40

Fishes and forestry. Worldwide watershed interactions and management (2004)

Mon, 26 Oct 2015 10:08:29

Le domaine public fluvial, un héritage du passé qui module aujourd'hui la réflexion sur la gestion de la biodiversité. Les zones humides de la Loire sous observation. In: Fleuves et marais, une histoire au croisement de la nature et de la culture. BURNOUF J. & LEVEAU P. (2004)

Mon, 26 Oct 2015 10:04:16

Parasiten der Weseraale (1998-2003) im Vergleich mit anderen Fliessgewässern Mittel- und Westeuropas (2004)

Mon, 26 Oct 2015 10:03:28

Distribution and growth of submerged aquatic vegetation in the Piedmont section of the James River, Virginia (2004)

Mon, 26 Oct 2015 10:03:11

Selection of (bio) indicators to assess effects of freshwater use in wetlands: a case study of s'Albufera de Mallorca, Spain (2004)

Mon, 26 Oct 2015 10:02:48

Freshwater Fisheries in Central & Eastern Europe: the Challenge of Sustainability (2004)

Mon, 26 Oct 2015 10:02:33

Macro-invertebrate functional groups in freshwater and marine sediments: A common mechanistic classification

Fri, 7 Jun 2019 14:15:21

Functional group definitions in aquatic ecology vary depending on the type of ecosystem (e.g., marine compared to fresh water ecosystems, stream compared to lake ecosystems). Since the benthic environment functions as the major storage and recycling compartment for virtually all material that flows in the aquatic system, biological processes that take place there are interesting models for identification of the different invertebrate functions. The accurate species function includes the effects of an organism on the abiotic as well as the biotic properties of the habitats. Therefore, a functional group may be defined as a group of species that share common biogeochemical and interspecific attributes. The main difficulty of applying this definition in aquatic ecosystems comes from the high diversity of organism functions (compared to terrestrial systems) that potentially exist at different levels: i) interspecific diversity supported by the large morphological and behavioural diversity of organisms, reinforced by a low degree of species redundancy; ii) intraspecific functional diversity due to changes in life history strategy during the life cycle, and enhanced by optimal foraging theory. The major question remains to find accurate functional group sizes and classifications that permit the distinction of the different biological activities involved in ecosystem key processes without missing other biological functions. After reviewing some of the problems in current functional classifications of benthic invertebrates, we propose a classification system based on the mechanical activities that characterize each species rather than consideration of the multiple consequences of these activities. This sorting strategy will result in a sub-classification of classical feeding groups into more precise functional groups. Such groups as bioturbation groups or functional feeding groups may be composed of representative taxa in both marine and freshwater environments.

Atlas des poissons et des crustacés (décapodes) d'eau douce de Nouvelle-Calédonie (2003)

Mon, 4 Apr 2022 10:25:48

Les ripisylves méditerranéennes (2003)

Mon, 26 Oct 2015 10:11:22

The freshwater fishes of Europe. 5. Part 2: Cyprinidae 2/2 (Barbus) (2003)

Mon, 26 Oct 2015 10:11:17

The ecology and management of wood in world rivers (2003)

Mon, 26 Oct 2015 10:09:42

Managing rivers wisely. Lessons from WWF's work for integrated river basin management (2003)

Mon, 26 Oct 2015 10:09:16

The freshwater fishes of Europe. 8. Part 1: Mugilidae, Atherinidae, Atherinopsidae, Blenniidae, Odontobutidae, Gobiidae 1 (2003)

Mon, 26 Oct 2015 10:08:41

Mountain streams. Life running waters (2003)

Mon, 26 Oct 2015 10:07:45

Strategies for restoring river ecosystems: sources of variability and uncertainty in natural and managed systems (2003)

Mon, 26 Oct 2015 10:07:18

Spring hunting changes the regional movements of migrating greater snow geese (2003)

Mon, 26 Oct 2015 10:06:53

Les habitats de Oued El Abid. Classification selon les systèmes MedWet et CAR-ASP (2003)

Mon, 26 Oct 2015 10:05:41

Changements environnementaux, dérives écologiques et perspectives de restauration du Rhône français: bilan de 200 ans d'influences anthropiques (2003)

Mon, 26 Oct 2015 10:05:28

L'impact du ragondin sur les milieux en Saône et Loire (2003)

Mon, 26 Oct 2015 10:02:55

Freshwater Crayfish in South Tyrol (italy): Distribution and Protection Measures of Endangered Austropotamobius Pallipe

Sun, 19 Mar 2023 18:04:45

Freshwater crayfish are among the most endangered animals in Europe. Information on freshwater crayfish in the Italian province of South Tyrol was insufficient until the recent studies on their historical and present distribution, which showed the alarming facts that only 15 standing and running waters remained as freshwater crayfish habitats, carrying the native Austropotamobius pallipes and the allochthonous Astacus astacus, Orconectes limosus, and Pacifastacus leniusculus. Still ongoing alterations or degradation of water bodies have contributed to the high degree of population decline and loss. While the exotic crayfish O. limosus and P. leniusculus could develop higher densities, most of the autochthonous A. pallipes populations were weak and consisted only of a few individuals. Three populations of A. pallipes, however, remained in a good condition, representing potential sources for recovery programs. Protection measures currently carried out in South Tyrol involve breeding, restocking and reintroduction of autochthonous A. pallipes individuals in ecological intact water bodies. , Les écrevisses autochtones sont considérées comme animaux les plus en danger de nos eaux européennes. Bien que l’information soit nécessaire, celle sur les écrevisses du Tyrol du sud (Italie) était pratiquement inexistante. Récemment, plusieurs études sur leur répartition géographique historique et actuelle ont sonné l’alarme en montrant que seuls 15 cours d’eau hébergeaient les écrevisses dans cette province italienne, dont 12 avec Austropotamobius pallies, un avec Astacus astacus, un avec Pacifastacus leniusculus et un avec Orconectes limosus. Les altérations et dégradations de cours d’eau, qui continuent encore de nos jours, ont poussé plusieurs populations d’écrevisses autochtones à régresser voire même à disparaître. Tandis que les espèces exotiques P. leniusculus et O. limosus ont pu se développer assez fortement, la plupart des populations d’A. pallipes restent faibles et ne sont constituées que d’individus peu nombreux. Trois populations d’A. pallipes, néanmoins, demeurent en bonne condition, représentant donc les sources potentielles pour les programmes de réintroduction. Les mesures de protection effectuées actuellement dans le Tyrol du sud concernent surtout l’élevage et la réintroduction d’A. pallipes autochtone dans les eaux écologiquement intactes.

PRELIMINARY OBSERVATION OF OCCASIONAL MORTALITY IN THE POPULATION OF FRESHWATER CRAYFISH IN THE PICOS DE EUROPA (ASTURIAS, SPAIN)

Sun, 19 Mar 2023 18:04:45

Factors associated with mortality in a population of Austropotamobius italicus, formerly A. pallipes lusitanicus, were monitored during two years in the Natural Park of Picos de Europa. Dead crayfish were submitted to the laboratory for analysis. No mass mortalities occurred during these two years. The number of mortalities was not constant throughout the year, with highest levels observed in May-June and November-December. Over the rest of the year mortality remained low. A high proportion of dead crayfish displayed signs of predation, mainly observed during the months of November and December. Other causes associated with mortality were storms and the process of moulting, especially in June. The presence of Saprolegnia in females during the reproduction season was also observed. Symptoms of Porcelain disease, or the presence of Psorospermium, were not observed during this study. , Les facteurs associés avec la mortalité d’une population d’Austropotamobius italicus, anciennement dénommée A. pallipes lusitanicus située dans le parc naturel de Picos de l’Europe ont été étudiées durant deux ans. Les écrevisses mortes ont été analysées au laboratoire. Aucune mortalité de masse n’est apparue pendant ces deux ans. Le nombre d’écrevisses mortes n’est pas constant pendant l’année, les mois de mai-juin et de novembre-décembre présentent les chiffres les plus élevés de mortalité. Le reste de l’année, la mortalité est basse. Un haut pourcentage des animaux présente des signes de prédation. Cela peut être observé principalement pendant les mois de novembre-décembre. D’autres causes telles que les crues et la mue ont été recensées en juin principalement. La présence de Saprolegnia chez les femelles a également été montrée durant la saison de reproduction. La maladie de la porcelaine et la présence de Psorospermium n’ont pas été observées pendant cette étude.

Hazard Analysis of Exotic Pathogens of Potential Threat to European Freshwater Crayfish.

Sun, 19 Mar 2023 18:04:44

Managers, scientists, fishermen and farmers who work with freshwater crayfish understand clearly the severe affects that the introduction of an exotic pathogen can have on freshwater crayfish populations. This acute awareness is due to the severe impact on native European freshwater crayfish of the introduction of crayfish plague fungus Aphanomyces astaci. This issue has been thoroughly covered in previous reviews. The potential impact of other pathogens on European freshwater crayfish has not been addressed. This paper presents a hazard analysis of pathogens of freshwater crayfish exotic to Europe, which is the first step of import risk analysis. , Les aménageurs, les scientifiques, les pêcheurs et les éleveurs qui travaillent avec les écrevisses comprennent clairement les effets sévères que l’introduction d’un pathogène exotique peut avoir sur les populations d’écrevisses. Cette conscience aiguë est due à l’impact grave sur les écrevisses européennes indigènes de l’introduction du champignon de la peste des écrevisses (Aphanomyces astaci). Ce problème a été complètement exposé dans des revues précédentes. L’impact potentiel d’autres microbes pathogènes sur les écrevisses européennes n’a pas été examiné. Cet article présente une analyse de risque des pathogènes des écrevisses non encore présents en Europe, qui est la première étape de l’analyse de risque d’importation.

A Review of International Biosecurity Policy Development in Relation to Movements of Freshwater Crayfish

Sun, 19 Mar 2023 18:04:44

Freshwater crayfish are frequently traded, both alive (for human consumption or for fisheries/aquaculture stocking) and as processed products (e.g. fresh or frozen, cooked or uncooked). As the experience in Europe with crayfish plague has shown, there can be significant risks of translocating pathogens with such trade. Such risks can be assessed in an import risk analysis process. This paper will concentrate on describing the principles of import risk analysis (IRA) with particular reference to freshwater crayfish. , Des écrevisses sont fréquemment commercées, vivantes (pour la consommation humaine ou pour les besoins des pêches et de l’aquaculture) et en tant que produits traités (par exemple frais ou congelé, cuit ou cru). L’expérience en Europe avec la peste des écrevisses a montré qu’il peut y avoir des risques significatifs de transfert de pathogènes avec un tel commerce. De tels risques peuvent être évalués dans un processus d’analyse de risque d’importation. Cet article se concentrera sur la description des principes de l’analyse de risque d’importation (IRA), l’accent étant mis plus particulièrement sur les écrevisses d’eau douce.

Species of Branchiobdellidae (annelida) on Freshwater Crayfish in South Tyrol (northern Italy)

Sun, 19 Mar 2023 18:04:43

Twenty-eight freshwater crayfish were collected from 8 streams and one small lake in the province of South Tyrol (North Italy) from autumn 1999 to spring 2001, in order to investigate the presence of branchiobdellidans. At 6 of the streams the white clawed crayfish (Austropotamobius pallipes italicus) was collected, while the noble crayfish (Astacus astacus), the exotic species: signal crayfish (Pacifastacus leniusculus) and spiny-cheek crayfish (Orconectes limosus) were respectively caught at the other 2 streams and at the lake. Except for O. limosus, branchiobdellidans were observed on all crayfish examined. On noble crayfish, specimens of Branchiobdella italica and Branchiobdella hexodonta were found on the same host. Branchiobdella italica was largely recovered from all white clawed crayfish. The specimens of signal crayfish were found to carry only Xironogiton victoriensis. , A partir de l’automne 1999 jusqu’au printemps 2001 en Tyrol du Sud, 28 écrevisses ont été prélevées dans 8 ruisseaux et un petit lac dans le but de vérifier la présence des Branchiobdellidae. L’écrevisse à pieds blancs (Austropotamobius pallipes italicus) a été trouvée dans 6 ruisseaux, l’écrevisse à pieds rouges (Astacus astacus) et l’écrevisse de Californie (Pacifastacus leniusculus) dans deux ruisseaux et l’écrevisse américaine (Orconectes limosus) dans le lac. A l’exclusion de l’écrevisse américaine, on a trouvé chez toutes les autres espèces des Branchiobdellidae. Chez l’écrevisse à pieds rouges, Branchiobdella italica et Branchiobdella hexodonta sont présentes. Chez toutes les écrevisses à pieds blancs, on a relevé une grande quantité de B. italica alors que chez les écrevisses de Californie on a retrouvé seulement le Xironogiton victoriensis.

The Freshwater Crayfish Austropotamobius Pallipes (lereboullet, 1858) in Liguria, Nw Italy: Implications for Management at the Regional Leve

Sun, 19 Mar 2023 18:04:43

Since 1990, field surveys have been undertaken in Liguria to assess the distribution and status of Austropotamobius pallipes populations. In this region, crayfish stocks were found in three bioclimatic regions: Alpine, Mediterranean and Continental. Although epidemic diseases and invasive alien crayfish have been recorded, modifications of freshwater habitats have to be considered as the most significant threats to native crayfish stocks. Regarding management, the Regional Administration of Liguria proposed 18 Sites of Community Importance (SCI) containing crayfish populations, in the framework of the Habitats Directive (92/43/EEC). Since public managers need to take informed decisions in land-use management and conservation a numeric biodiversity map, composed by a georeferred database connected to a geographic information system (GIS), has been implemented. This regional system is composed by 22 different layers containing all the available information about the location of species and habitats of conservation interest. This system is now routinely used by regional administrators in environmental impact assessment. Finally, emphasis is placed on the need of promoting research programmes on the long-term monitoring of crayfish populations. , En Ligurie, un inventaire sur la répartition de l’écrevisse à pattes blanches Austropotamobius pallipes est en cours depuis 1990. Actuellement, les stocks astacicoles sont présents dans les régions biogéographiques alpines, continentales et méditerranéennes. La présence d’écrevisses allochtones et de maladies parasitaires a été signalée, mais la dégradation des habitats naturels est sans doute la menace la plus importante pour l’espèce. Dans le cadre de la Directive Communautaire 92/43 « Habitats et Espèces », l’Administration Régionale de la Ligurie a proposé 123 Sites d’Importance Communautaire (SIC), dont 18 contiennent des populations d’écrevisses. Du point de vue gestionnaire, tous les sites de A. pallipes ont été informatisés et inclus dans un Système Informatique Géographique (SIG) régional dans lequel les habitats et les espèces d’intérêt patrimonial sont localisés. Ce système est utilisé de façon routinière par les services techniques régionaux pour l’évaluation des projets d’aménagement du territoire. Enfin, on remarque la nécessité d’établir des protocoles scientifiques pour le suivi à long terme des populations d’écrevisses.

Effects of Bacillus thuringiensis israelensis on Black Flies and Nontarget Macroinvertebrates and Fish in a Large River

Mon, 21 Aug 2023 15:18:12

Six field experiments tested the effects of the microbial pesticide Bacillus thuringiensis israelensis (Bti) on pestiferous black flies (primarily the Simulium jenningsi group) as well as nontarget macroinvertebrates and fish in the Susquehanna River, Pennsylvania. The response of black fly drift after the Bti application was similar across all experiments. Black fly drift increased significantly within 0.5 h after application, peaked 2-3 h after application, and then remained high for several hours. Significant changes in drift were observed after Bti application for 31 of the 50 nontarget macroinvertebrate taxa examined, but none of these taxa exhibited an increase in drift density similar in magnitude and timing to that of black flies. Furthermore, none of the 31 taxa exhibited the same drift changes in all experiments, as was observed for black flies; most of the taxa exhibited a drift density change during only one posttreatment sample period within a single experiment. Most nontarget macroinvertebrates therefore appeared unaffected by Bti, including the chironomid midge Rheotanytarsus, which was previously reported as Bti sensitive. Fish species composition and abundance in riffles did not change following the Bti application. The importance of black flies in fish diets varied dramatically among individual fish, sampling periods, and years. Variation in the number of black flies in fish diets may reflect variation in discharge as well as in black fly and fish behavior. The number of black flies consumed did not increase immediately after Bti application (when black fly drift was high) or decrease later (when black fly densities were suppressed). Fish condition and short-term (7-10-d) growth rates did not change consistently across experiments. The absence of repeated responses that paralleled the magnitude of black fly responses suggests that the statistically significant changes observed for nontarget macroinvertebrates and fish were unrelated to the Bti application. Thus, we found no evidence that a single Bti application affected nontarget macroinvertebrates and fish to an ecologically significant extent.

Flux sédimentaires et morphogénèse récente dans le chenal du Rhône aval (2002)

Wed, 11 Jun 2025 14:43:17

Cette recherche, basée sur l'utilisation d'outils nouveaux dans le Rhône inférieur, a permis de mieux cerner les flux sédimentaires actuels, leur évolution et impact depuis plus de 150 ans. Dans la première partie, nous avons montré la dépendance du système deltai͏̈que aux apports liquides et solides du bassin versant. Nous avons ainsi pu déterminer les influences allochtones qui modifient l'hydrologie, la sédimentologie et la morphologie du Rhône aval. L'étude du système deltai͏̈que a permis d'établir les contraintes locales qui modifient, atténuent ou amplifient les effets des forçages externes. Nous avons notamment retenu les contraintes lithologiques, morphologiques (chenal et berges) et les équipements locaux qui ont des conséquences sur les modifications morphologiques et sur les transits sédimentaires. Dans la deuxième partie, nous avons exposé les résultats des mesures expérimentales effectuées sur les flux liquides et solides. Ces résultats, pour la plupart inédits dans le delta du Rhône, mettent en évidence l'organisation des flux liquides et sédimentaires dans les trois dimensions de l'espace. L'ensemble des données acquises permet la réévaluation des flux sédimentaires du Rhône : nous proposons un tonnage annuel moyen de MES compris entre 9 et 10 millions de tonnes. Enfin, dans la dernière partie, cette étude a permis de reconstituer l’évolution morphodynamique du Rhône inférieur depuis près de 150 ans. Après avoir montré que l'évolution morphologique du Rhône aval était précoce, nous avons mis en évidence l'impact des contraintes locales et externes sur les réponses morphodynamiques du bas Rhône. Nous avons pu montrer que les contraintes locales intervenaient à différentes échelles spatio-temporelles dans l'évolution du chenal. Il a également été démontré que le système deltai͏̈que à charge de fond sableuse développait des temps de réaction-relaxation plus courts que ceux des tronçons et organismes amont à charge de fond caillouteuse.

Atlas des poissons et des crustacés d'eau douce de la Martinique (2002)

Mon, 4 Apr 2022 10:25:48

A sourcebook for conducting biological assessments and developing biodiversity visions for eco-region conservation. 2: Freshwater regions (2002)

Mon, 26 Oct 2015 10:11:33

Limnological Reports Volume 34 (2002)

Mon, 26 Oct 2015 10:10:56

Conservation of freshwater fishes: options for the future (2002)

Mon, 26 Oct 2015 10:10:37

Management and ecology of lake and reservoir fisheries (2002)

Mon, 26 Oct 2015 10:10:29

Caractérisation de la biodiversité dans la ripisylve de l'oued Soummam: cas de la végétation et des oiseaux (2002)

Mon, 26 Oct 2015 10:10:26

Mediterranean riparian woodlands (2002)

Mon, 26 Oct 2015 10:10:21

Ripisylves méditerranéennes (2002)

Mon, 26 Oct 2015 10:10:21

The ecohydrology of South American rivers and wetlands (2002)

Mon, 26 Oct 2015 10:08:49

Aquatic ecology of the Mondego River basin. Global importance of local experience (2002)

Mon, 26 Oct 2015 10:08:23

Mécanique des fluides appliquée. Eléments incompressibles dans les circuits, canaux et rivières, autour des structures et dans l'environnement (2002)

Mon, 26 Oct 2015 10:07:26

The role of protected areas in freshwater fish conservation. In: Conservation of freshwater fishes: options for the future. COLLARES-PEREIRA M.J., COWX I.G. & COELHO M.M. (2002)

Mon, 26 Oct 2015 10:06:03

Impact of the North Atlantic oscillation on Middle Eastern climate and streamflow (2002)

Mon, 26 Oct 2015 10:06:00

Effects of agricultural runoff on native amphibians in the Lower Fraser River Valley, British Columbia, Canada (2002)

Mon, 26 Oct 2015 10:05:54

Quels objectifs de restauration pour un ancien polder de la basse vallée du Vistre? (2002)

Mon, 26 Oct 2015 10:04:06

Restoration of floodplain wetlands: opening polders along a coastal river in Mediterranean France, Vistre marshes (2002)

Mon, 26 Oct 2015 10:04:06

Medium-term changes in suspended sediment delivery to the ocean: Consequences of catchment heterogeneity and river management (Rhône River, France) (2002)

Mon, 26 Oct 2015 10:03:34

Decadal variability of the Danube River flow in the lower basin and its relation with the North Atlantic oscillation (2002)

Mon, 26 Oct 2015 10:03:25

Effects of bensulfuron-methyl and cinosulfuron on growth of four freshwater species of phytoplankton (2002)

Mon, 26 Oct 2015 10:03:20

Fluctuations of macrobenthic populations: a link between climate-driven river run-off and sole fishery yields in the Gulf of Lions (2002)

Mon, 26 Oct 2015 10:03:18

Long-term changes in a Mediterranean benthic community: relationships between the Polychaete assemblages and hydrological variations of the Rhône River (2002)

Mon, 26 Oct 2015 10:03:18

A global action plan for conservation of tortoises and freshwater turtles. Strategy and funding prospectus 2002-2007 (2002)

Mon, 26 Oct 2015 10:02:53

Atlas des poissons d'eau douce de France (2001)

Mon, 26 Oct 2015 10:11:36

Flux de matière en étangs piscicoles extensifs: rétention, sédimentation, exportation (2001)

Mon, 26 Oct 2015 10:11:17

The freshwater fishes of Europe. 5. Part 3: Cyprinidae 2/3 (Carassius to Cyprinus). Gasterosteidae (2001)

Mon, 26 Oct 2015 10:11:17

Etude préliminaire à la mise en place d'un tableau de bord anguille sur le bassin Rhône-Méditerranée-Corse (2001)

Mon, 26 Oct 2015 10:11:15

Etude préliminaire à la mise en place d'un tableau de bord anguille sur le bassin Rhône-Méditerranée-Corse. Rapport annexe: Fiches signalétiques des différents obstacles expertisés (2001)

Mon, 26 Oct 2015 10:11:15

Cartographie des renouées du Japon sur le réseau hydrographique du bassin Rhône Méditerranée Corse. 1: Méthodologie et problématique de l'étude (2001)

Mon, 26 Oct 2015 10:10:57

Cartographie des renouées du Japon sur le réseau hydrographique du bassin Rhône Méditerranée Corse. 2: Résultats cartographiques et interprétations des données (2001)

Mon, 26 Oct 2015 10:10:57

Biologie des poissons d'eau douce européens (2001)

Mon, 26 Oct 2015 10:10:53

Roselières: moins qu'hier, plus que demain. Agir sur un habitat clé des oiseaux d'eau. Inventaire et caractérisation des roselières de l'est de la France (1998-2000) (2001)

Mon, 26 Oct 2015 10:09:58

Atlas des poissons d'eau douce de France (2001)

Mon, 26 Oct 2015 10:09:12

Rapporto sullo stato delle acque dei principali fiumi in Toscana (2001)

Mon, 26 Oct 2015 10:08:49

River restoration in Europe. Practical approaches (2001)

Mon, 26 Oct 2015 10:08:29

Documento marco para la desarrollo del proyecto Donana 2005. Regeneracion hidrica de las cuencas y cauces vertientes a la marismas del Parque Nacional de Donana (2001)

Mon, 26 Oct 2015 10:07:57

Guidelines for rehabilitation and management of floodplains. Ecology and safety combined (2001)

Mon, 26 Oct 2015 10:07:17

Molecular phylogeny and evolution of the freshwater eel, genus Anguilla (2001)

Mon, 26 Oct 2015 10:07:06

Assessment of water pollution and suitability to fish life in six Italian rivers (2001)

Mon, 26 Oct 2015 10:06:57

Kinship analysis of Pacific salmon: insights into mating, homing, and timing of reproduction (2001)

Mon, 26 Oct 2015 10:06:49

Freshwater fish habitat science and management in Greece (2001)

Mon, 26 Oct 2015 10:06:40

Stream and riparian management for freshwater turtles (2001)

Mon, 26 Oct 2015 10:06:40

Famille des Centrarchidae. In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:25

La perche-soleil Lepomis gibbosus (Linné, 1758). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:25

Le carassin argenté Carassius gibelio (Bloch, 1782). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:02

L'épinoche Gasterosteus aculeatus (Linné, 1766). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:02

L'ordre des Gastérostéiformes. Famille des Gasterosteidae. Clé des espèces de Gasterosteidae présentes en France. In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:02

Famille des Poeciliidae. La gambusie Gambusia affinis holbrooki (Girard, 1859). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:01

La grémille Gymnocephalus cernuus (Linné, 1758). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:06:01

Alternative mating strategies in Atlantic salmon and brown trout (2001)

Mon, 26 Oct 2015 10:05:26

A genetic evaluation of mating system and determinants of individual reproductive success in Atlantic salmon (Salmo salar L.) (2001)

Mon, 26 Oct 2015 10:05:26

Réhabilitation de marais sur un domaine de la basse vallée du Vistre (La Musette). In: Programme national de recherche. Recréer la nature: réhabilitation, restauration et création d'écosystèmes. Principaux résultats scientifiques et opérationnels. CHAPUIS J.L., BARRE V. & BARNAUD G. (2001)

Mon, 26 Oct 2015 10:05:13

La carpe commune Cyprinus carpio (Linné, 1758). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:04:24

Le mulet à grosse tête Mugil cephalus (Linné, 1758). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:04:24

L'ordre des Mugiliformes. Famille des Mugilidae. In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:04:24

A phylogeny of freshwater eels inferred from mitochondrial genes (2001)

Mon, 26 Oct 2015 10:04:15

Fluctuations of landings and environmental conditions in the north-western Mediterranean Sea (2001)

Mon, 26 Oct 2015 10:04:14

Fish diversity in streams and rivers. In: Global biodiversity in a changing environment. Scenarios for the 21st century. CHAPIN F.S., SALA O.E. & HUBER-SANNWALD E. (2001)

Mon, 26 Oct 2015 10:03:36

Habitat use by 0+ fish in an old-engineered river reach (Lower Rhône, France): relative importance of habitat heterogeneity and hydrological variability (2001)

Mon, 26 Oct 2015 10:03:35

L'athérine Atherina boyeri (Risso, 1810). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:03:23

L'ordre des Athériniformes. In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:03:23

Le pseudorasbora Pseudorasbora parva (Schlegel, 1842). In: Atlas des poissons d'eau douce de France KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:03:23

Le goujon Gobio gobio (Linné, 1766). In: Atlas des poissons d'eau douce de France. KEITH P. & ALLARDI J. (2001)

Mon, 26 Oct 2015 10:03:22

Ecozone du Forez. Suivi du plan de gestion quinquennal (1997-2001). Chronique de l'année 2000 (2001)

Mon, 26 Oct 2015 10:02:53

Cannibalism governing mortality of juvenile brown trout, Salmo trutta, in a regulated stream (2001)

Mon, 26 Oct 2015 10:02:48

A study of a comprehensive solution to the problems of the Wloclawek dam and reservoir. Anticipated social, economic and environmental effects. An overview (2001)

Mon, 26 Oct 2015 10:02:39

Water ways and sustainable development (2001)

Mon, 26 Oct 2015 10:02:39

Limnomysis benedeni Czerniavsky: a Pontocaspian mysid new for the freshwaters of France (Crustacea, Mysidacea)

Wed, 12 Jun 2019 11:15:13

Danubian populations of the Pontocaspian mysid Limnomysis benedeni Czerniavsky, 1882, passing through the Main-Danube-Canal, rapidly expanded into waters of the Rhine system. This species is now recorded for the first time from France, where it represents the first true freshwater mysid. Temporal and spatial characteristics of this invasion point to a combination of hydrodynamic and anthropogenic modes of dispersal, which may favour a rapid colonization of the net of navigable inland waterways in France. Limnomysis appears as an omnivorous species in laboratory, but stomach contents indicate that the animals are essentially herbivorous and detritivorous in nature. From known bionomical data, no important effect is expected on the invaded freshwaters at ecosystem level.

Aménagement des milieux = Water systems arrangement (2000)

Mon, 26 Oct 2015 10:11:10

Fonctionnement des zones humides riveraines du cours moyen des rivières. Analyse et modélisation de la genèse des hétérogénéités structurales et fonctionnelles. Application à la Seine moyenne (2000)

Mon, 26 Oct 2015 10:11:10

Atti del Convegno: Zone umide d'acqua dolce. Tecniche e strategie di gestione della vegetazione palustre Ostiglia (ITA) 15/03/99 (2000)

Mon, 26 Oct 2015 10:11:08

Global perspectives on river conservation. Science, policy and practice (2000)

Mon, 26 Oct 2015 10:11:01

Hydraulique fluviale. Ecoulement et phénomènes de transport dans les canaux à géométrie simple (2000)

Mon, 26 Oct 2015 10:09:43

Recull de ponencies de les 1° Jornades sobre estrategies per la conservacio i restauracio del bosc de Ribera (2000)

Mon, 26 Oct 2015 10:09:17

The strategy for the green corridor of the Guadiamar River. Fundamentals of the strategy (2000)

Mon, 26 Oct 2015 10:08:38

Atlas niv Odry = Atlas obszarow zalewowych Odry = Oder-Auen-Atlas (2000)

Mon, 26 Oct 2015 10:08:08

Contrat de rivière Touloubre. Dossier préalable de candidature (2000)

Mon, 26 Oct 2015 10:07:41

River Cetina watershed and the adjacent coastal area. Environmental and socio-economic profile (2000)

Mon, 26 Oct 2015 10:07:33

Inland flood hazards. Human, riparian, and aquatic communities (2000)

Mon, 26 Oct 2015 10:07:18

Size-specific mortality and natural selection in freshwater turtles (2000)

Mon, 26 Oct 2015 10:06:40

Occurence and load of selected herbicides and metabolites in the lower Mississipi River (2000)

Mon, 26 Oct 2015 10:06:14

L'Anjou au naturel. Paysage, faune et flore de nos rivières (2000)

Mon, 26 Oct 2015 10:06:07

The rehabilitation of the marble trout, Salmo marmoratus in the upper Soca River basin, Slovenia (2000)

Mon, 26 Oct 2015 10:06:03

Morphological variation in hybrids between Salmo marmoratus and alien Salmo species in the Volarja stream, Soca River basin, Slovenia (2000)

Mon, 26 Oct 2015 10:05:52

Lifetime success and interactions of farm salmon invading a native population (2000)

Mon, 26 Oct 2015 10:05:32

First results on migrating shad (Alosa fallax) and mullet (Mugil cephalus) echocounting in a lock on the Rhône River (France) using a split-beam sounder, and relationships with environmental data and fish caught (2000)

Mon, 26 Oct 2015 10:05:11

Mechanisms for development and maintenance of biodiversity in neotropical floodplains. In: Biodiversity in wetlands: assessment, function and conservation. GOPAL B., JUNK W.J. & DAVIS J.A. (2000)

Mon, 26 Oct 2015 10:04:35

Effects of riparian vegetation removal on nutrient retention in a Mediterranean stream (2000)

Mon, 26 Oct 2015 10:03:20

Structure de l'habitat et biologie de reproduction du héron garde-boeuf, Bubulcus ibis, dans une colonie de la vallée de la Soummam (Petite Kabylie, Algérie) (2000)

Mon, 26 Oct 2015 10:03:12

La caractérisation de l’emplacement de 511 nids de Hérons garde-bœufs, Bubulcus ibis, implantés clans une colonie de la vallée de la Soummam (Petite Kabylie, Algérie), a permis d’établir la chronologie d’installation et les modalités du choix initial et préférentiel du site d’implantation du nid. Le suivi régulier de 58 nids préalablement marqués a permis de calculer des paramètres relatifs au succès reproducteur. La reproduction du garde-bœufs a lieu de la fin-mars à la fin-juillet, avec un pic d’installation noté en mai. La taille moyenne des pontes (2,77 ± 0,56, N = 64), le nombre moyen d’envol par nid (1,69 ±0,87, N = 64) et le succès de reproduction (57,3 %) sont relativement faibles, comparés à ceux notés dans d’autres régions méditerranéennes. Les pertes subies par les pontes et les nichées sont dues, principalement, à l’action du vent (Sirocco) qui entraîne des chutes. Les individus nicheurs installent préférentiellement leurs nids sur les arbres les plus hauts, à la hauteur la plus élevée et dans la position la plus proche du tronc principal. Ce comportement de sélection est un nouvel aspect observé pendant la nidification de l’espèce.

Redd superimposition by introduced rainbow trout, Oncorhynchus mykiss, on native charrs in a Japanese stream (2000)

Mon, 26 Oct 2015 10:03:00

Fator de condiçao e relaçao hepato e esplenossomatica em teleosteos de agua doce naturalmente parasitados (2000)

Mon, 26 Oct 2015 10:02:59

The importance of stream-wetland-systems for biodiversity: a tropical perspective. In: Biodiversity in wetlands: assessment, function and conservation. GOPAL B., JUNK W.J. & DAVIS J.A. (2000)

Mon, 26 Oct 2015 10:02:44

Plan Migrateurs Rhône-Méditerranée. Le Rhône et ses affluents retrouvent leurs grands migrateurs. (2000)

Mon, 26 Oct 2015 10:02:29

Atlas des poissons et des crustacés d'eau douce de la Réunion (1999)

Mon, 4 Apr 2022 10:25:49

Qualité des eaux du Rhône. Evolution 1969-1995 (1999)

Mon, 26 Oct 2015 10:11:31

The freshwater fishes of Europe. 5. Part 1: Cyprinidae 2/1 (Rhodeus to Capoeta) (1999)

Mon, 26 Oct 2015 10:11:17

Opération Grands Cormorans. Suivi du grand cormoran (Phalacrocorax carbo sinensis) sur les Gardons: effectif et prédation (1999)

Mon, 26 Oct 2015 10:10:02

Contrat de rivière Cadière et étang de Bolmon. Dossier préalable de candidature (1999)

Mon, 26 Oct 2015 10:09:37

Parasites of North American freswater fishes (1999)

Mon, 26 Oct 2015 10:09:29

Oiseaux piscivores et gestion piscicole dans le département du Tarn (1999)

Mon, 26 Oct 2015 10:09:15

Caractérisation taxinomique et suivi biologique de la population d'Alose feinte du Rhône (Alosa fallax rhodanensis, Roule 1924). Campagne d'études 1997 (1999)

Mon, 26 Oct 2015 10:09:03

La reproduction de l'Alose feinte du Rhône (Alosa fallax rhodanensis, Roule 1924) en aval du barrage de Vallabrègues. Campagne d'études 1997 (1999)

Mon, 26 Oct 2015 10:09:03

Suivi de la migration et de la pêcherie d'Alose feinte du Rhône (Alosa fallax rhodanensis, Roule 1924) au niveau du barrage de Vallabrègues. Campagne d'études 1997 (1999)

Mon, 26 Oct 2015 10:09:02

Suivi de la pêcherie d'Alose feinte du Rhône (Alosa fallax rhodanensis, Roule 1924) sur le bassin du Rhône. Campagne d'études 1999 (1999)

Mon, 26 Oct 2015 10:09:02

The Indus River. Biodiversity, resources, humankind (1999)

Mon, 26 Oct 2015 10:08:45

Conséquences d'une arrivée massive d'eau douce sur la communauté de gobies (Téléostéens, Poissons) d'une lagune méditerranéenne: l'exemple de l'étang du Vaccarès (Camargue, France) (1999)

Mon, 26 Oct 2015 10:08:24

Suivi de la remontée des aloses dans le Bassin du Rhône. Synthèse du suivi des pêcheries de 1996 à 1998. Campagne d'études 1998 (1999)

Mon, 26 Oct 2015 10:08:16

Assessing the sustainability and biological integrity of water resources using fish communities (1999)

Mon, 26 Oct 2015 10:07:51

The hydrology of the Nile (1999)

Mon, 26 Oct 2015 10:07:43

Lebendige Elbe . Streifzüge durch die Natur- und Kulturlandschaft Elbe (1999)

Mon, 26 Oct 2015 10:07:38

Prise en compte de la biodiversité dans l'étude, la gestion et la restauration des annexes fluviales en France et en Europe (1999)

Mon, 26 Oct 2015 10:07:19

The impact of rice pesticides on the aquatic ecosystems of the Sacramento River and Delta (California) (1999)

Mon, 26 Oct 2015 10:06:29

Délestage de la Cadière vers l'étang. Etude de faisabilité (1999)

Mon, 26 Oct 2015 10:05:58

Die Zukunft unserer Flüsse. Ausgewählte Revitalisierungsprojekte in Österreich = The future of Austrian rivers (1999)

Mon, 26 Oct 2015 10:05:41

Balance del plan de actuaciones en torno al accidente de las minas de Aznalcollar (23 abril 1999) (1999)

Mon, 26 Oct 2015 10:05:38

Contamination by Polycyclic Aromatic Hydrocarbons (PAHs) in French and European rivers (1999)

Mon, 26 Oct 2015 10:05:35

Spawning of anadromous rainbow trout, Oncorhynchus mykiss (Walbaum): a threat to sea trout, Salmo trutta L., populations? (1999)

Mon, 26 Oct 2015 10:04:23

Input, storage and distribution of large woody debris along mountain river continuum, the Drôme River, France (1999)

Mon, 26 Oct 2015 10:03:38

Groundwater and fish: insights from northern America (1999)

Mon, 26 Oct 2015 10:03:33

Flood and debris-flow effects on Virginia brook trout populations (1999)

Mon, 26 Oct 2015 10:03:07

Channel changes due to river regulation: the case of the Piave River, Italy (1999)

Mon, 26 Oct 2015 10:03:03

Microhabitat characteristics and reproductive status of male Euchordodes nigromaculatus (Nematomorpha) (1999)

Mon, 26 Oct 2015 10:02:57

Influence of streamside cover and stream features on temperature trends in forested streams of Western Oregon (1999)

Mon, 26 Oct 2015 10:02:36

La reproduction de l'Alose feinte du Rhône (Alosa fallax rhodanensis, Roule 1924) en aval du barrage de Vallabrègues. Campagne d'études 1997 (1999)

Mon, 26 Oct 2015 10:02:29

Conservation of the flora and vegetation of the freshwater oligotrophic temporary ponds in mediterranean France

Fri, 24 Mar 2023 18:42:02

In Mediterranean France, freshwater, oligotrophic, temporary ponds figure among some of the most interesting ecosystems from a biologic and biogeographic point of view. Following a definition and classification of vernal pools, the geomorphologic or anthropic origins of these formations will be discussed. A survey of areas rich in such pools has allowed us to describe 19 "hotspots" in the regions of Provence-Alpes-Cote d'Azur, Languedoc-Roussillon, and Corsica. The assessment of negative human impact and the imposing number of rare plant in rapid regression (49 taxa) reveal a great need for conservation and management efforts treating the totality of ecocomplexes containing vernal pools. Conservation measures should be undertaken at the metapopulation and landscape levels, with the eventual restoration of sites affected by eutrophisation in mind (Grammont, parts of Roque-Haute...). To better understand their evolution and succession, further analysis and refinement of the dynamics of these plant communities in regard to climatic, edaphic, and anthropic parameters, in normal and disturbed conditions, is needed. Such studies are essential for the management of these fragile ecosystems.

La gestion du littoral T.2 (1998)

Thu, 28 Apr 2022 10:44:52

Les oiseaux de l'ensemble Haut Rhône/Lac du Bourget. Bilan et évaluation patrimoniale pour un classement du site au titre de la convention de Ramsar (1998)

Mon, 26 Oct 2015 10:11:20

Ribamod. River basin modelling, management and flood mitigation concerted action (1998)

Mon, 26 Oct 2015 10:10:48

Les systèmes fluviaux anthropisés: le fonctionnement des systèmes fluviaux à l'échelle du bassin = Man and river systems: the functioning of river systems at basin scale (1998)

Mon, 26 Oct 2015 10:10:45

Etude et bilan. Les frayères potentielles d'Aloses sur les bas et les moyens Gardons (1998)

Mon, 26 Oct 2015 10:10:43

The biology of streams and rivers (1998)

Mon, 26 Oct 2015 10:09:48

Environmental biology and morphodynamics of the sofie Chondrostoma toxostoma (Cyprinidae), with emphasis on early development (1998)

Mon, 26 Oct 2015 10:09:43

The river valleys of the Maltese Islands. Environment and human impact (1998)

Mon, 26 Oct 2015 10:09:34

Patterns in freshwater fish ecology (1998)

Mon, 26 Oct 2015 10:08:50

Dernières avancées techniques en reproduction des salmonidés d'eau douce: 1. Les lignées gynogénétiques et les clones chez la truite arc-en-ciel. 2. La maîtrise de la reproduction chez les salmonidés d'eau froide (1998)

Mon, 26 Oct 2015 10:06:50

La gestion des boisements de rivières. 1: Dymamique et fonctions de la ripisylve (1998)

Mon, 26 Oct 2015 10:06:35

La gestion des boisements de rivières. 2: Définition des objectifs et conception d'un plan d'entretien (1998)

Mon, 26 Oct 2015 10:06:35

Distribution and seasonal occurrence of Anguillicola crassus (Nematoda: Dracunculoidea) in the European eel Anguilla anguilla L. from rivers of North Portugal (1998)

Mon, 26 Oct 2015 10:06:25

A wetland managed for agriculture as an interface between the Rhône river and the Vaccarès lagoon (Camargue, France): transfers of water and nutrients (1998)

Mon, 26 Oct 2015 10:06:17

A bibliography of the fishes of the Tigris-Euphrates Basin (1998)

Mon, 26 Oct 2015 10:06:13

Systematic biodiversity in the freshwater fishes of Iran (1998)

Mon, 26 Oct 2015 10:06:13

Pesticides and PCB contaminants in fish and tadpoles from the Kaweah River basin, California (1998)

Mon, 26 Oct 2015 10:05:58

El cernicalo primilla (Falco naumanni) en el valle del Ebro: poblaciones, uso del habitat, demografia y conservacion (1998)

Mon, 26 Oct 2015 10:05:46

Das Buch der Flüsse. 74 Flußstrecken von österreichweiter Bedeutung = The book of Austrian Rivers (1998)

Mon, 26 Oct 2015 10:05:41

Behavior of migratory fish passing a lock on the River Rhône, France (1998)

Mon, 26 Oct 2015 10:05:11

Estimation hydroacoustique du nombre de poissons migrateurs franchissant l'écluse de Beaucaire-Vallabrègues (Rhône) (1998)

Mon, 26 Oct 2015 10:05:11

Mollusques, crustacés, arachnides et autres petits invertébrés des eaux douces (1998)

Mon, 26 Oct 2015 10:04:30

Relationship of trout recruitment to snowmelt runoff flows and adult trout abundance in six Colorado mountains streams (1998)

Mon, 26 Oct 2015 10:04:22

Bassin Rhône Méditerranée Corse. Guide technique n°2: détermination de l'espace de liberté des cours d'eau (1998)

Mon, 26 Oct 2015 10:04:11

The input of nutrients by the Rhône river into the Mediterranean Sea: recent observations and comparison with earlier data (1998)

Mon, 26 Oct 2015 10:03:54

Distribucion y densidad de la trucha Oncorhynchus mykiss (Salmoniformes: Salmonidae) en los Andes venezolanos (1998)

Mon, 26 Oct 2015 10:03:42

Repatriace ohrozenych rostlin a zivocichu do revitalizovanych ricnich niv = Repatriation of endangered plants and animals into the restored floodplains (1998)

Mon, 26 Oct 2015 10:03:32

Scanning electron microscopy and intraspecific variation in Euchordodes nigromaculatus from New Zealand (1998)

Mon, 26 Oct 2015 10:03:15

Fluctuating asymmetry in an insect host: a big role for big parasites? (1998)

Mon, 26 Oct 2015 10:02:57

Fluctuating asymmetry in an ornamental trait in the cave weta, Pleioplectron simplex Hutton (Othoptera: Rhaphidophoridae): no role for parasites (1998)

Mon, 26 Oct 2015 10:02:57

The present statuts of freshwater crayfish in Ireland

Sun, 19 Mar 2023 18:04:48

A plan of restauration in Navarra for the native freshwater crayfish species of Spain, Austropotamobius pallipes

Sun, 19 Mar 2023 18:04:47

Allozyme diversity of european freshwater crayfish of the genius Austropotamobius

Sun, 19 Mar 2023 18:04:46

Italian freshwater decapods: Exclusion between the crayfish Austropotamobius pallipes (FAXON) and the crab Potamon fluviatile (HERBST)

Sun, 19 Mar 2023 18:04:45

Dynamics of marine sands (1997)

Fri, 24 Jun 2022 11:45:39

Introductions de poissons d'eau douce et d'écrevisses en Camargue: historique, origines et modifications des peuplements

Tue, 16 Jul 2019 14:05:53

RÉSUMÉ Treize espèces de poissons dulçaquicoles exotiques sont actuellement recensées en Camargue, dans le delta du Rhône. Parmi elles, onze sont naturalisées. Deux écrevisses américaines ont également été recensées. Pour illustrer les modifications intervenues dans les peuplements de poissons à la suite de ces introductions, nous prenons l'exemple d'un canal de drainage. Les impacts potentiels (compétition alimentaire, hybridation) sur les espèces autochtones sont identifiés et discutés. Nous avons tenté de caractériser chez Pseudorasbora parva les traits d'histoire de vie qui ont permis l'établissement rapide de cette espèce exotique dans le canal. Des suggestions sont émises en conclusion, pour une meilleure compréhension des interactions entre espèces introduites et faune autochtone. ABSTRACT Thirteen introduced freshwater fish species were recorded in the Camargue (Rhone Delta, Southern France). Eleven of them have established a population. Two American freshwater crayfishes were also introduced. The example of a drainage canal (studied between 1989 and 1995) was chosen to illustrate the changes in fish assemblages that occurred after those introductions. Depending on the year, the relative abundance (CPUE) of exotic species represented from 27% to 33% of the total catch. The potential impacts of those introductions (diet overlap, hybridization) on natural fish communities are identified and discussed. Life history traits of Pseudorasbora parva, an Asiatic species first recorded in 1993 in the canal, have been studied ; some of them might explain the successful and fast establishment of this species in the Camargue. In conclusion, suggestions and recommendations are proposed for a better understanding of the mechanisms involved in the interactions between introduced species and native communities.

Suivi de la pêcherie en aval de l'usine-écluse de Vallabrègues. Estimation des captures des pêcheurs amateurs aux engins. Campagne d'études 1996 (1997)

Mon, 26 Oct 2015 10:11:14

Suivi de la reproduction de l'Alose feinte du Rhône. Campagne 1994 (1997)

Mon, 26 Oct 2015 10:11:04

Influence des éclusées hydroélectriques sur la structure et la dynamique des populations d'invertébrés d'une rivière pyrénéenne de moyenne montagne (1997)

Mon, 26 Oct 2015 10:10:44

Inventaire des frayères potentielles d'aloses sur les Bas Gardons (1997)

Mon, 26 Oct 2015 10:10:43

Etude du réseau hydraulique des basses plaines de l'Aude rive droite. Diagnostique des périmètres gérés par les associations syndicales autorisées (1997)

Mon, 26 Oct 2015 10:10:42

Impact des aménagements hydroélectriques sur l'écosystème Rhône (1997)

Mon, 26 Oct 2015 10:10:31

Schéma de gestion et d'aménagement de la Touloubre et de son bassin versant. Phase 1: état des lieux diagnostic. Rapport d'études (1997)

Mon, 26 Oct 2015 10:10:25

Cours d'eau et indices biologiques. Pollutions. Méthodes. IBGN (1997)

Mon, 26 Oct 2015 10:09:50

Suivi de la reproduction de l'Alose feinte du Rhône. Campagne d'étude 1995 (1997)

Mon, 26 Oct 2015 10:09:50

Etude de la migration des Aloses. Utilisation des techniques acoustiques. Campagne 1997 (1997)

Mon, 26 Oct 2015 10:09:38

Suivi de la reproduction de l'Alose feinte du Rhône en aval du barrage de Beaucaire-Vallabrègues. Campagne d'études 1996 (1997)

Mon, 26 Oct 2015 10:08:49

Atlas des sites d'intérêt écologique de la vallée du Rhône. Guide méthodologique (1997)

Mon, 26 Oct 2015 10:08:41

Etudes des zones potentielles de frai des aloses sur la Cèze (1997)

Mon, 26 Oct 2015 10:08:01

Le retour des Aloses sur la Cèze: suivi de la frayère de substitution du Port de l'Ardoise, Laudun (30). Mai-juin 1997 (1997)

Mon, 26 Oct 2015 10:08:01

Atlas de l'île de Miribel-Jonage (1997)

Mon, 26 Oct 2015 10:07:42

Structured-population models in marine, terrestrial, and freshwater systems (1997)

Mon, 26 Oct 2015 10:07:34

Modelling of biogeochemical processes and spatial patterns in freshwater wetlands (1997)

Mon, 26 Oct 2015 10:07:30

Patchwork. Patch use, habitat exploitation and carrying capacity for water birds in Dutch freshwater wetlands (1997)

Mon, 26 Oct 2015 10:07:30

Evolution des paléoenvironnements fluviaux dans la plaine deltaïque du Rhône de l'Antiquité au Haut Moyen Age. In: Crau, Alpilles, Camargue. Histoire et archéologie. BAUDAT M. (1997)

Mon, 26 Oct 2015 10:07:05

Préservation et réhabilitation de population de truites sauvages de montagne (1997)

Mon, 26 Oct 2015 10:06:19

Diet of the turtle Deirochelys reticularia on the Savannah River Site, South Carolina (1997)

Mon, 26 Oct 2015 10:05:52

Development of a geography-referenced regional exposure assessment tool for European rivers - GREAT-ER contribution to GREAT-ER #1 (1997)

Mon, 26 Oct 2015 10:05:35

The precarious state of the rivers of Malta (1997)

Mon, 26 Oct 2015 10:05:01

River habitat fragmentation in Malta: A danger needing investigation (1997)

Mon, 26 Oct 2015 10:05:01

Distribution and abundance of native Bonneville cutthroat trout (Oncorhynchus clarki Utah) in southwestern Utah (1997)

Mon, 26 Oct 2015 10:04:59

Diversité des stratégies d'histoire de vie sous un régime multifactoriel de perturbations: les amphibiens de la plaine alluviale du Haut-Rhône français (1997)

Mon, 26 Oct 2015 10:04:37

Zone de Saxy, sur le bas Rhône. Projet d'arrêté de biotope. Dossier scientifique et technique (1997)

Mon, 26 Oct 2015 10:04:05

Changes in the mollusc fauna of nathal Taninim (1856-1986) (1997)

Mon, 26 Oct 2015 10:03:59

Diet of the Pelomedusid turtle Peltocephalus dumerilianus in the Venezuelan Amazon (1997)

Mon, 26 Oct 2015 10:03:40

The natural flow regime. A paradigm for river conservation and restoration (1997)

Mon, 26 Oct 2015 10:03:36

Introductions de poissons d'eau douce et d'écrevisses en Camargue: Historique, origines et modifications des peuplements (1997)

Mon, 26 Oct 2015 10:03:22

Satellite remote sensing of river inundation area, stage , and discharge: a review (1997)

Mon, 26 Oct 2015 10:03:07

Contrasting movement and activity of large brown trout and rainbow trout in Silver Creek, Idaho (1997)

Mon, 26 Oct 2015 10:02:38

Functional analysis of European wetland ecosystems phase 1 (FAEWE): the function of river marginal wetland esosystems ; improving the science base for the development of procedures of functional analysis ; final report EC DG XII STEP-CT90-0084 (1996)

Thu, 28 Apr 2022 09:50:50

Atlas des poissons d'eau douce de Guyane. T. 1 (1996)

Mon, 4 Apr 2022 10:25:49

Les méthodes biologiques d'évaluation de la qualité des milieux aquatiques (1996)

Fri, 28 Apr 2017 14:17:53

Managing aquatic vegetation with grass carp. A guide for water resource managers (1996)

Mon, 26 Oct 2015 10:10:48

[Prespa. History of man and nature] (1996)

Mon, 26 Oct 2015 10:10:46

Schéma directeur d'aménagement et de gestion des eaux SDAGE du Bassin Rhône Méditerranée Corse. 1: Orientations fondamentales. Mesures opérationnelles et modalités de mise en oeuvre (1996)

Mon, 26 Oct 2015 10:10:36

Schéma directeur d'aménagement et de gestion des eaux SDAGE du Bassin Rhône Méditerranée Corse. 2: Fiches thématiques. Réglementation et préconisations du SDAGE (1996)

Mon, 26 Oct 2015 10:10:36

Schéma directeur d'aménagement et de gestion des eaux SDAGE du Bassin Rhône Méditerranée Corse. 3: Cartographie des objectifs et des priorités (1996)

Mon, 26 Oct 2015 10:10:36

Schéma directeur d'aménagement et de gestion des eaux SDAGE du Bassin Rhône Méditerranée Corse. Mode d'emploi. Glossaire et index (1996)

Mon, 26 Oct 2015 10:10:36

Stock assessment in inland fisheries (1996)

Mon, 26 Oct 2015 10:10:30

The freshwater fish endemic to the Northern Mediterranean region. An action plan for their conservation (1996)

Mon, 26 Oct 2015 10:10:28

Les milieux naturels des Gardons. Etude bibliographique (1996)

Mon, 26 Oct 2015 10:10:26

Occupation d'un espace fluvial par les Diptères chironomidés à l'aval du Rhône: répartition des espèces selon la nature du substrat et les conditions de débit (1996)

Mon, 26 Oct 2015 10:09:55

Les chironomidés (Diptera) de l'Aude, rivière méditerranéenne des Pyrénées orientales. Impact d'une crue catastrophique (1996)

Mon, 26 Oct 2015 10:09:50

Suivi des frayères potentielles d'Aloses sur la rivière Ardèche en aval de St-Martin-d'Ardèche et le Rhône court-circuité entre le barrage de Donzère-Mondragon et l'embouchure de l'Ardèche. Campagne d'études 1996 (1996)

Mon, 26 Oct 2015 10:09:50

Etude de la migration des Aloses. Utilisation des techniques acoustiques. Campagne 1996 (1996)

Mon, 26 Oct 2015 10:09:38

Protecting the freshwater ecosystems of Southern Europe. Strategy for an integrated approach (1996)

Mon, 26 Oct 2015 10:09:33

The fishes of Champaign County, Illinois, during a century of alterations of a prairie ecosystem (1996)

Mon, 26 Oct 2015 10:09:04

Caractérisation morphologique et biologie de l'Alose feinte du Rhône. Campagne d'études 1996 (1996)

Mon, 26 Oct 2015 10:09:03

Conservation of freshwater fish (1996)

Mon, 26 Oct 2015 10:08:54

Conservation des poissons d'eau douce (1996)

Mon, 26 Oct 2015 10:08:54

Le peuplement piscicole du Bas-Rhône: occupation d'un espace fluvial aménagé et typologie des sites de nursery et de refuge (1996)

Mon, 26 Oct 2015 10:08:31

Etude de faisabilité d'une zone Ramsar dans la Bassée et la Basse Vallée de l'Aube (1996)

Mon, 26 Oct 2015 10:08:22

River restoration. Selected extracts from the rivers handbook (1996)

Mon, 26 Oct 2015 10:08:18

Atlas des poissons d'eau douce de Guyane. Tome 1 (1996)

Mon, 26 Oct 2015 10:08:16

The marble trout Salmo trutta marmoratus, Cuvier 1817 in the Soca River Basin, Slovenia. An action plan (1996)

Mon, 26 Oct 2015 10:08:13

Lifelines. The world's great rivers (1996)

Mon, 26 Oct 2015 10:07:17

Les lignes de vie.Les grands fleuves de la terre (1996)

Mon, 26 Oct 2015 10:07:17

Provence-Alpes-Côte d'Azur. Carte de la qualité des cours d'eau. Synthèse des données acquises de 1988 à 1994 (1996)

Mon, 26 Oct 2015 10:07:13

The glass eel fishery and the by-catch in the Rio Minho after one decade (1981-1982 and 1991-1992) (1996)

Mon, 26 Oct 2015 10:07:06

Assessment of ecosystem changes in response to freshwater inflow of the Kromme River Estuary, St. Francis Bay, South Africa: a network analysis approach (1996)

Mon, 26 Oct 2015 10:07:00

Distribution et flux de chrome et de mercure dans le Rhône à Arles durant la période Juin 1994-Mai 1995. In: 7° Rencontres de l'Agence Régionale pour l'Environnement Provence Alpes Côte d'Azur Digne-les-Bains 24-27/10/1995 (1996)

Mon, 26 Oct 2015 10:06:16

Quelques facteurs de la biodiversité végétale dans les prairies humides des corridors fluviaux (1996)

Mon, 26 Oct 2015 10:06:13

Saumon 2000. Etats d'avancement des projets début 1996 (1996)

Mon, 26 Oct 2015 10:06:08

Bacillariophycées, Desmidiées et Euglénophycées de la région de Kisangani (Zaïre) (1996)

Mon, 26 Oct 2015 10:05:19

River Bureau, Ministry of construction, Japan (1996)

Mon, 26 Oct 2015 10:04:41

Environmental fate of rice pesticides in California (1996)

Mon, 26 Oct 2015 10:04:12

The decline in catches of European elver 1980-1992 (1996)

Mon, 26 Oct 2015 10:03:55

Acheloos. Eternal river. Ultimate destruction (1996)

Mon, 26 Oct 2015 10:03:35

Les débits solides du Rhône à proximité de son embouchure durant l'année hydrologique 94-95. In: 7° Rencontres de l'Agence Régionale pour l'Environnement ARPE Provence Alpes Côte d'Azur Digne-les-Bains 24-27/10/1995 (1996)

Mon, 26 Oct 2015 10:03:35

Multi-scale approach to species-habitat relationships: juvenile fish in a large river section (1996)

Mon, 26 Oct 2015 10:03:35

Le suivi expérimental des charges micro-polluantes véhiculées par le Rhône. In: 6° Rencontres de l'Agence Régionale pour l'Environnement ARPE Provence Alpes Côte d'Azur Saint-Cyr-sur-Mer (FRA) 14-15/11/1995 & GAP (FRA) 16-18/11/1995 (1996)

Mon, 26 Oct 2015 10:03:35

Actions of the European Union for river and floodplain conservation (1996)

Mon, 26 Oct 2015 10:03:18

Diatomées de quelques cours d'eau des environs de Yangambi (cuvette centrale zaïroise, région du Haut-Zaïre) (1996)

Mon, 26 Oct 2015 10:03:02

Les radioéléments artificiels (émetteurs gamma et plutonium) dans le Rhône à Arles en 1994-1995. In: 7° Rencontres de l'Agence Régionale pour l'Environnement ARPE Provence Alpes Côte d'Azur Digne-les-Bains 24-27/10/1995 (1996)

Mon, 26 Oct 2015 10:02:58

Feeding relations among cyprinids in the Lozoya River (Madrid, Central Spain) (1996)

Mon, 26 Oct 2015 10:02:51

Reproduction chez nos poissons (1996)

Mon, 26 Oct 2015 10:02:33

Premiers éléments de caractérisation biologique et taxinomique de l'Alose feinte du Rhône (1994 et 1995) (1996)

Mon, 26 Oct 2015 10:02:29

A new sampling method for freshwater shrimps

Fri, 29 Apr 2022 12:03:24

Are fish introductions a threat to endemic freshwater fishes in the northern Mediterranean region?

Fri, 27 Oct 2017 15:24:09

Seventy species of exotic or transplanted fish species have been introduced into this region, 60% of them in the last 40 years. The effects of these introductions on endemic species have rarely been described. The few exceptions are: hybridization of Salmo marmoratus with Salmo trutta; the extinction of three endemic species of Phoxinellus in a Turkish lake owing to the introduction of Stizostedion lucioperca; and the spatial displacement of Aphanius in sites where Gambusia affinis occurs. A further phenomenon possibly attributable to the introduction of exotic fish is the increased turbidity in Lake Mikri Prespa following the introduction of Carassius auratus. Because of the paucity of information, the effects of introductions on endemic species remain controversial. It is therefore essential to initiate conservation action plans, for each catchment in wetland areas rich in endemic fish. An awareness campaign directed at land managers and decision-makers on the role and importance of fish in the functioning of aquatic ecosystems must also be undertaken very soon.

Mediterranean endemic freshwater fishes of Italy

Thu, 26 Oct 2017 14:44:05

In Italy, as in several other circum-Mediterranean countries, there is a unique assemblage of endemic freshwater fishes. Speciation processes, especially of endemic primary or near-primary freshwater fish, most probably occurred during the Lago Mare era of the Mediterranean (about 5 million years bp). However, the present-day distribution patterns are surely the result of events that occurred more recently, from the Pleistocene until historical times. However, natural events are now being superseded by anthropogenic interference with fish faunas. Among the various negative human factors the most harmful is the introduction of non-native species, which in Italy are responsible for the present catastrophic situation. Of the 71 species currently with natural self-sustaining populations in Italian waters, only 45 are natives. Of the latter, only 16 (or fewer) have not been subjected to deliberate human transfers. In Italy there about 28 endemic Mediterranean taxa, but most have either been deliberately or accidentally introduced to areas outside their natural range. The result of this persistent practice on a little known and unique fish fauna is zoogeographic pollution, massive cases of hybridization and loss of genetic identity by local native populations. The problem of freshwater fish conservation is not a matter of public concern in Italy. Sport fishing has a political and economic value and introductions are legally carried out and ‘welcomed’ by most fishermen; most biologists and conservationists are either unaware or unconcerned.

Conservation status of endemic freshwater fish in Spain

Thu, 26 Oct 2017 14:09:43

The present conservation status of the endemic freshwater fish of Spain is reviewed and compared with a former list made in 1986. Ten taxa (species and subspecies) are exclusively endemic to Spanish waters, 13 are Iberian endemics (Spain and Portugal), while three other species are also found in neighbouring European (France and Italy) or African (Algeria) countries. Endemic species belong to the families Clupeidae (33% of the native taxa), Cyprinidae (87%), Cobitidae (100%) and Cyprinodontidae (100%). A greater part of the endemic fish fauna is threatened, since three taxa are endangered, five vulnerable, seven rare and two insufficiently known.

Freshwater fish in Anatolia, Turkey

Thu, 26 Oct 2017 14:06:39

The southern, western and north-western regions of Anatolia have abundant freshwater resources in the form of rivers, lakes and lagoons. In the past, these aquatic habitats were unpolluted and had very rich fish populations, but some water courses have started to become polluted in the last 20 years. This is because Turkey is a country that is developing very fast, both industrially and in agricultural terms. As a result of the large numbers of major towns and various types of factory, some species have been particularly affected by industrial pollution and generally the populations of fish living in these habitats have greatly diminished in recent years. The waste waters from these sites are discharged via rivers and lakes into the Sea of Marmara, the Aegean and the Mediterranean Seas. Some factories are equipped with filtration systems or purification plants, but at present most have no form of effluent treatment. Twenty species and ten subspecies of fish are described that are endemic to Turkey and neighbouring countries. One endemic species (Tor canis) is now extinct in Turkish waters, and three species (Alosa fallax nilotica, Aphanius fasciatus and Blennius fluviatilis) are endemic to the northern Mediterranean. It is essential as a first priority that conservation measures are taken to protect certain species and subspecies.

Endangered freshwater fishes of Greece

Thu, 26 Oct 2017 14:00:09

The freshwater fish fauna of Greece includes 106 species of which 79 are native primary species. Of these 38 species are endemic to Greece and southern parts of neighbouring countries. Endangered species are divided into three groups: wholly endangered, locally endangered and rare and threatened. In the first group are eight taxa, usually found in a very restricted area (Eudontomyzon hellenicus, Alosa caspia vistonica, Pseudophoxinus beoticus, Ladigesocypris ghigii ghigii, Barbus euboicus, Barbus cyclolepis cholorematicus, Pungitius hellenicus and Knipowitschia goerneri). The second group includes five species with a wide area of distribution but some local populations which are extinct or in obvious decline (Salmo trutta, Pseudophoxinus stymphalicus, Vimba melanops, Valencia letourneuxi, Proterorhinus marmoratus). The third group comprises nine endemic taxa, mainly with a wide distribution in Greece, or widely distributed in Europe but represented in Greece by local populations, sometimes recognized as subspecies (Phoxinellus pleurobipunctatus, Barbus prespensis, Gobio kessleri banarescui, Gobio uranoscopus elimeius, Carassius carassius, Orthrias barbatulus vardarensis, Pungitius platygaster, Knipowitschia thessala, Economidichthys pygmaeus). These taxa often have rare or threatened local populations. The main reasons for the decline of fish species are: agricultural and industrial activity, overfishing, partial or total destruction of many karstic springs, public and private works abstracting water, drainage, irrigation, tourist and industrial installations, dams, mixing of fish faunas of different origin and introduction of exotic species.

The conservation of freshwater fish: Past and present experience

Thu, 26 Oct 2017 13:56:44

The conservation of fish and fish communities has received little attention relative to other vertebrates. Yet across Eurasia and North America, numerous important stocks of various fish species have been eliminated and there are now thousands of lakes and rivers which are fishless or possess only degraded communities. The main problems are caused by engineering works, industrial and domestic pollution, acidification, fishing and fishery management, and land use practices. The major conservation objective, perhaps fortified by legislation, must be habitat restoration and management, but short-term programmes can usefully involve translocations, captive breeding and cryopreservation. Fish conservation programmes are needed in every country in order to rescue endangered species and reverse the downward trends facing important fish communities by managing the lake and river systems concerned.

Conservation status of freshwater fish of Albania

Thu, 26 Oct 2017 13:19:49

Of the 67 species of freshwater fish and one species of lamprey present in Albania, 43 species are endemic to the north Mediterranean area and 13 have been introduced and have established populations. Five other species have been introduced, but do not reproduce. There are no data available on the status, distribution and ecology of the endemic fishes of Albania with the exception of the Salmonidae living in Lake Ohrid (Salmothymus ohridanus, Salmo letnica and Salmo letnica lumi). Data on the morphology and biology of these three salmonids are presented. Research on the freshwater fish of Albania is badly needed.

Status of freshwater fish in Croatian Adriatic river systems

Thu, 26 Oct 2017 11:19:54

Approximately 64 species of freshwater fish occur in Croatian Adriatic river systems. Fifty of these are native, the remainder being introduced or translocated. Of the 40 species endemic to the Mediterranean area 11 occur only in Croatia. Others are distributed mostly in the karstic area of Bosnia and Hercegovina, some in Montenegro, Macedonia, Slovenia and Italy, while a few are distributed throughout the whole northern Mediterranean. River regulation, hydroelectricity generation and industrial pollution, plus very restricted distributions, are the main causes for endemic fish being endangered. The most important Croatian endemic fish are the six species of the genus Paraphoxinus and Leuciscus ukliva, Leuciscus polylepis, Leuciscus svallize, Aulopyge hugeli, Salmothymus obtusirostris, Knipowitschia mrakovcici, and the endemic subspecies of Salmo trutta.

Legal aspects of the conservation of endemic freshwater fish in the northern Mediterranean region

Thu, 26 Oct 2017 11:10:46

Several — anthropogenic — influences are identified which cause the decline of freshwater fish, such as overfishing, introduction of alien taxa, habitat degradation and habitat loss. Whilst the problem of overfishing and introduction of alien taxa from the point of view of legislation (not implementation!) is relatively easy to handle, the conservation and protection of aquatic habitats proves to be a complex and difficult task. Aquatic habitats — being in a way the ‘vitals’ of their respective ecosystems — are extremely sensitive to harmful influences. They are affected directly or indirectly by a vast number of human activities. Therefore quite a number of different legal issues and also several administrative bodies are involved in the problem. Besides those concerning the use of aquatic resources in general, international instruments exist which aim at preserving habitats and/or their flora and fauna — including aquatic habitats. Among these, the EC Flora, Fauna and Habitat Directive and the Berne Convention explicitly include freshwater fish endemic to the northern Mediterranean region in their appendices. These instruments oblige member states — among others — to conserve these species and their habitats and/or certain sensitive aquatic habitats. They do, however, only establish general obligations which need to be implemented by more detailed provisions in national legislation. The establishment of specially protected areas for protected species (e.g. in France) or the development of recovery plans for endangered species (e.g. in Spain) are two examples. However, research on the subject of national legislation for the protection of endemic freshwater fish should be developed with the aid of local experts. To this end general information on legal and administrative means and methods at a national level is also given.

Freshwater fish and their conservation in Portugal

Thu, 26 Oct 2017 10:57:37

There are 36 species and subspecies of freshwater fish and three migratory species in Portugal. Eleven have been introduced, 13 are endemic to the Iberian Peninsula and two live exclusively in Portugal (Chondrostoma lusitanicum and Rutilus macrolepidotus). Industrica pollution and the introduction of exotic fish species are the most serious conservation problems for Portuguese endemic fish.

Conservation of native freshwater fishes in the Mediterranean-type climate of California, USA: A review

Thu, 26 Oct 2017 10:54:26

The native fish fauna of California, like the faunas of other regions of the world with Mediterranean climate, is declining rapidly: 63% of the 115 taxa are extinct or in danger of becoming extinct. The native fishes fall into three major groups: (1) diadromous fishes and their stream-resident derivatives; (2) large, long-lived freshwater dispersant fishes, mostly Cyprinidae; and (3) small freshwater dispersant fishes in isolated inland habitats, such as desert springs. In this respect, the fish fauna of California bears a closer resemblance to the fish fauna of Europe than it does to that of eastern North America. The native fish fauna is in trouble because most of the precipitation occurs in the northern half of the state or at high elevations, while most of the human need for water is in the southern half of the state, at low elevations. The result has been the construction of dams and reservoirs on every major stream in the state and thousands of kilometres of aqueducts. In addition, poor land use has devastated many drainages, introduced fishes have replaced native fishes, and fisheries have depleted some stocks. Major droughts have exacerbated these problems. Most of the extinct or endangered species are either native to small isolated habitats or to big rivers. The fishes have continued to decline despite conservation efforts using such powerful legal tools as the Endangered Species Act, the California Department of Fish and Game Code, and the Public Trust Doctrine. The poor state of California's fish fauna is a strong indication that many other endemic aquatic organisms, much more poorly known than the fishes, are in trouble as well. Protecting fishes will thus help to protect aquatic biodiversity in California. With this in mind, a general plan for protecting California's aquatic biota is presented. The plan has two main components: (1) legal protection for species in immediate danger of extinction and (2) development of a statewide system of protected waters called Aquatic Diversity Management Areas (ADMAs). For the latter component, a framework is presented that consists of (1) criteria for the design of ADMAs; (2) a system for ranking the suitability of aquatic habitats for protection of the native biota; (3) a classification system for California's waters; and (4) a long-term scheme for protecting aquatic biodiversity statewide.

Status of freshwater fishes in the Adriatic catchment of Slovenia

Thu, 26 Oct 2017 10:51:20

There are 35 species and subspecies of fish and two lamprey species in the Adriatic catchment of Slovenia. Five have been introduced and five transplanted. None of the regionally endemic fishes nor the lampreys live exclusively in Solvenia. Of these, Salmo Marmoratus, and Lethenteron zanandreai are threatened while Chondrosoma genei became extinct after the introduction of Chondrostoma nasus nasus into the area around 1960.

Future prospects for the freshwater fish fauna of the north Mediterranean region

Thu, 26 Oct 2017 10:51:18

The fresh waters of the north Mediterranean region possess a unique and diverse ichthyofauna with 229 endemic fish taxa in 13 families. With diverse threats to wetlands in the area and their increasing mismanagement many fishes are under threat and several taxa have become extinct in recent years. Following workshop discussions among specialists, a series of proposals is now put forward which is designed to reverse this trend. Within these proposals is the concept that clean water is desirable for both people and fish and that acceptable compromises must be the way to share this vital resource in the future. Managing water resources in the Mediterranean region is clearly going to be a key feature in the future development of this area and major issues must be resolved soon to avoid serious conflicts over water use in the 21st century.

Stream ecology. Structure and function of running waters (1995)

Mon, 26 Oct 2015 10:11:29

Dynamique spatio-temporelle des peuplements de poissons estuariens en Guinée. Relations avec le milieu abiotique (1995)

Mon, 26 Oct 2015 10:11:17

Zoogeography of fresh waters. 3. Distribution and dispersal of freshwater animals in Africa, Pacific areas and South America (1995)

Mon, 26 Oct 2015 10:11:17

Amélioration des modèles prédictifs d'habitat de la truite fario. Echelles d'échantillonnage. Intégration des chroniques hydrologiques (1995)

Mon, 26 Oct 2015 10:10:49

Atlas du Bassin Rhône Méditerranée Corse (1995)

Mon, 26 Oct 2015 10:10:36

Endemic freshwater fishes of the Northern Mediterranean Region (1995)

Mon, 26 Oct 2015 10:10:28

Elementi di idrobiologia. La gestione delle risorse idriche, un esempio di applicazione: l'ecosistema fluviale dell'Orco (1995)

Mon, 26 Oct 2015 10:09:58

Predictive limnology. Methods for predictive modelling (1995)

Mon, 26 Oct 2015 10:09:36

L'aménagement des écosystèmes agro-piscicoles d'eau douce en milieu tropical (1995)

Mon, 26 Oct 2015 10:07:41

Sediment in streams. Sources, biological effects, and control (1995)

Mon, 26 Oct 2015 10:07:22

Fish species and varieties introduced into portuguese inland waters (1995)

Mon, 26 Oct 2015 10:07:10

Development and intercalibration of methods in nordic freshwater fish monitoring (1995)

Mon, 26 Oct 2015 10:07:06

Faunal community change in response to flow manipulation. In: The ecological basis for river management. HARPER D.M. & FERGUSON A.J.D. (1995)

Mon, 26 Oct 2015 10:07:05

Economic valuation of the environmental impacts of the Kayraktepe dam/hydroelectric power plant in Turkey. An exercise in contingent valuation and benefit-cost analysis (1995)

Mon, 26 Oct 2015 10:06:43

Current status of the riverine fishes of the French Mediterranean Basin (1995)

Mon, 26 Oct 2015 10:06:19

Freshwater fishes of Iran (1995)

Mon, 26 Oct 2015 10:06:13

Contrat et stratégie pour le plan d'action contre les inondations (1995)

Mon, 26 Oct 2015 10:06:08

Are fish introductions a threat to endemic freshwater fishes in the Northern Mediterranean region ? (1995)

Mon, 26 Oct 2015 10:06:02

Are introduced species the right answer to declining fisheries within the Mediterranean region? In: Protection of aquatic biodiversity. PHILIPP D.P. & al. (1995)

Mon, 26 Oct 2015 10:06:02

Responses of vegetation to a rise in water level at Kerkini Reservoir (1982-1991), a Ramsar site in Northern Greece (1995)

Mon, 26 Oct 2015 10:06:02

The floodplain of the river Strymon at Kerkini (northern Greece) was transformed into an irrigation reservoir by the construction of a dam in 1932 and subsequently enlarged in 1982. The aims of this study were to quantify the changes occurring in the various habitat types following raising of the waterlevel and to assess the stability of the plant communities present at this Ramsar site. The current hydrological regime, which has been stable since 1986, is typified by an increase in mean annual reservoir level of 2.2 m and by an increase in the annual range in level of 1.3 m. Landsat (1980, 1981, 1984, 1986, and 1988) and SPOT (1990) satellite images show a decrease in the area of grassland and shallow water areas, the very rapid disappearance of reedbeds, the appearance of beds ofNymphaea and the disappearance of half the forest area. The flooded forest, dominated bySalix alba, is a key habitat contributing to the biological richness of this wetland of international importance. The decrease in the forested area will continue because of the death of standing trees, the absence of regeneration under the new regime, the felling of trees and grazing. Management could be undertaken to ensure the survival of forested habitat and reedbeds at Kerkini, but this would require that the authorities take into account nature conservation and the protected status of the site and not raise the water level again.

Endemic freshwater fishes of the Northern Mediterranean region (1995)

Mon, 26 Oct 2015 10:06:01

Future prospects for the freshwater fish fauna of the North Mediterranean region (1995)

Mon, 26 Oct 2015 10:06:01

Quality of fresh water for fish and of shellfish water. Summary report on the state of application of the Directives 78/659/EEC and 79/923/EEC (1995)

Mon, 26 Oct 2015 10:05:38

Seasonal patterns of emergence in Odonata of a permanent stream in Southwestern Europe (1995)

Mon, 26 Oct 2015 10:05:34

Environmental and macroinvertebrate dynamics in the Lower Rhône River and a lateral dike field: a study matching two functioning descriptors (1995)

Mon, 26 Oct 2015 10:05:29

Monitoring fish stocks in relation to acidification in Norwegian watersheds (1995)

Mon, 26 Oct 2015 10:04:58

Fish and cyclostome migrations between fresh water and sea water: osmoregulatory modifications (1995)

Mon, 26 Oct 2015 10:04:50

Loire Nature: Un espace de liberté pour la Loire et l'Allier (1995)

Mon, 26 Oct 2015 10:04:41

Seasonal pulses in migrations of New Zealand diadromous fish and the potential impacts of river mouth closure (1995)

Mon, 26 Oct 2015 10:04:05

[Acheloos. The past, present and future] (1995)

Mon, 26 Oct 2015 10:03:39

L'aménagement durable des zones humides: respect de l'environnement et de la diversité biologique. In: L'aménagement des écosystèmes agro-piscicoles d'eau douce en milieu tropical. SYMOENS J.J. & MICHA J.C. (1995)

Mon, 26 Oct 2015 10:03:02

Sustainable use of the wetlands: respect for environment and biodiversity. In: The management of integrated freshwater agro-piscicultural ecosystems in tropical areas. SYMOENS J.J. & MICHA J.C. (1995)

Mon, 26 Oct 2015 10:03:02

The rivers handbook. Hydrological and ecological principles. 2. (1994)

Mon, 26 Oct 2015 10:10:50

Structure des peuplements de poissons à l'échelle du bassin rhodanien. Approche régionale et organisation longitudinale. Exploitation des captures par pêche aux engins (1994)

Mon, 26 Oct 2015 10:10:42

Rehabilitation of freshwater fisheries (1994)

Mon, 26 Oct 2015 10:10:30

Ecology and management of invasive riverside plants (1994)

Mon, 26 Oct 2015 10:10:22

Guide de protection des berges de cours d'eau en techniques végétales (1994)

Mon, 26 Oct 2015 10:09:06

Suivi de la dévalaison des alosons à Caderousse. Définition d'un protocole d'évaluation des résultats (1994)

Mon, 26 Oct 2015 10:08:43

Gestion et suivi des milieux fluviaux. L'expérience des réserves naturelles (1994)

Mon, 26 Oct 2015 10:08:41

Wetlands and shallow continental water bodies. 2: Case studies (1994)

Mon, 26 Oct 2015 10:08:21

Relations entre l'habitat physique et les poissons des zones à cyprinidés rhéophiles dans trois cours d'eau du bassin rhodanien: vers une simulation de la capacité d'accueil pour les peuplements (1994)

Mon, 26 Oct 2015 10:08:13

Débits des cours d'eau. 10 ans d'observations. Synthèse sur 200 stations de mesures en France 1984-1993 (1994)

Mon, 26 Oct 2015 10:08:07

Die Wasservögel am unteren Inn. Ergebnisse von 25 Jahren Wasservogelzählung: Dynamik der Durchzugs- und Winterbestände, Trends und Usachen (1994)

Mon, 26 Oct 2015 10:08:07

Qualité des cours d'eau. 10 ans d'observation. Synthèse sur 150 stations de mesures en France 1984-1993 (1994)

Mon, 26 Oct 2015 10:08:07

Reproductibilté du franchissement par les aloses des écluses de navigation sur le Bas-Rhône (1994)

Mon, 26 Oct 2015 10:08:00

Water quality and stress indicators in marine and freshwater ecosystems: Linking levels of organisation (individuals, populations, communities) (1994)

Mon, 26 Oct 2015 10:07:43

The new rivers and wildlife handbook (1994)

Mon, 26 Oct 2015 10:07:22

Monitoring of ecological change in wetlands of Middle Europe. Proceedings of an international workshop Linz (AUT) 10/1993 (1994)

Mon, 26 Oct 2015 10:07:02

Evolution de l'organisation et de l'occupation des terres de la basse vallée du Vistre de 1830 à nos jours (1994)

Mon, 26 Oct 2015 10:06:56

La Durance. Maîtrise d'un fleuve et aménagement de sa vallée (1994)

Mon, 26 Oct 2015 10:06:42

Etude floristique des domaines départementaux de la basse vallée du Vistre (Gard) (1994)

Mon, 26 Oct 2015 10:06:40

B-carotene and retinoids in eggs of Great Blue Herons (Ardea herodias) in relation to St Lawrence River contamination (1994)

Mon, 26 Oct 2015 10:06:39

The function, evaluation and relicts of near-natural floodplains. In: Limnologie aktuell. 2: Biologie der Donau. KINZELBACH (1994)

Mon, 26 Oct 2015 10:05:47

Determination of ecologically acceptable flows in rivers with seasonal changes in the density of macrophyte (1994)

Mon, 26 Oct 2015 10:05:00

Etude pédologique et cartographique d'un domaine de la basse vallée du Vistre en Petite Camargue (1994)

Mon, 26 Oct 2015 10:04:59

Differences between marine and freshwater fish larvae: implications for recruitment (1994)

Mon, 26 Oct 2015 10:04:50

Three new species of fishes of the genera Osteochilicthys (Cyprinidae), Travancoria (Balitoridae) and Horabagrus (Bagridae) from the Chalakudy River, Kerala, India (1994)

Mon, 26 Oct 2015 10:03:40

The role of fluid motion in the dynamics of phytoplankton in lakes and rivers. In: Aquatic ecology. Scale, pattern and process. GILLER P.S., HILDREW A.G. & RAFFAELLI D.G. (1994)

Mon, 26 Oct 2015 10:03:27

Saumon 2000 (1994)

Mon, 26 Oct 2015 10:03:14

Introduction à l'étude des eaux douces: eaux naturelles, eaux usées, eaux de boisson. Qualité et santé (1993)

Mon, 26 Oct 2015 10:11:01

Colour and clarity of natural waters. Science and management of optical water quality (1993)

Mon, 26 Oct 2015 10:10:24

The Hadejia-Nguru wetlands (1993)

Mon, 26 Oct 2015 10:09:28

Expertise pour l'accès des aloses et des anguilles aux affluents du Rhône. Inventaire des sites potentiels de frai d'aloses (1993)

Mon, 26 Oct 2015 10:09:01

Echelle d'observation et variabilité des abondances de juvéniles de poissons dans un secteur aval du Rhône (1993)

Mon, 26 Oct 2015 10:08:15

La Camargue et le Rhône, hommes et milieux (1993)

Mon, 26 Oct 2015 10:08:12

Freshwater biomonitoring and benthic macroinvertebrates (1993)

Mon, 26 Oct 2015 10:08:02

Periphyton development in relation to macro-scale (geology) and micro-scale (velocity) limiters in two gravel-bed rivers, New Zealand (1993)

Mon, 26 Oct 2015 10:06:45

Zone humide de la basse vallée du Var. Synthèse ornithologique 1980-1993 (1993)

Mon, 26 Oct 2015 10:06:40

Projet de Réserve Naturelle Volontaire des Iles du Vieux Rhône (1993)

Mon, 26 Oct 2015 10:06:25

The impact of desiccation of a freshwater marsh (Garcines Nord, Camargue, France) on sediment-water-vegetation interactions. 1: The sediment chemistry (1993)

Mon, 26 Oct 2015 10:05:56

The impact of desiccation of a freshwater marsh (Garcines Nord, Camargue, France) on sediment-water-vegetation interactions. 3: The fractional composition and the phosphate adsorption characteristics of the sediment (1993)

Mon, 26 Oct 2015 10:05:56

The pattern of natural mortality throughout the life cycle in contrasting populations of brown trout, Salmo trutta L. (1993)

Mon, 26 Oct 2015 10:05:40

Physical and chemical scales of pattern in freshwater lakes and reservoirs (1993)

Mon, 26 Oct 2015 10:05:23

The sizes of salmonid spawning gravels (1993)

Mon, 26 Oct 2015 10:04:27

Determination of population-limiting critical salmonid habitats in Colorado streams using the physical habitat simulation model (1993)

Mon, 26 Oct 2015 10:03:51

Plant invasions and the role or riparian habitats: a comparison of four species alien to central Europe (1993)

Mon, 26 Oct 2015 10:03:31

Les mammifères d'eau douce: leur vie, leurs relations avec l'homme (1993)

Mon, 26 Oct 2015 10:03:19

Dynamics of upstream migration in two species of tropical freshwater snails (1993)

Mon, 26 Oct 2015 10:03:14

Les diatomées des chutes de la Tshopo (Kisangani-Zaïre) (1993)

Mon, 26 Oct 2015 10:03:02

Deposition and resuspension of fine particles in a riverine dead zone (1993)

Mon, 26 Oct 2015 10:02:56

The impact of desiccation of a freshwater marsh (Garcines Nord, Camargue, France) on sediment-water-vegetation interactions. 2: The submerged macrophyte vegetation (1993)

Mon, 26 Oct 2015 10:02:49

Atlas préliminaire des crustacés décapodes d'eau douce de France (1993)

Mon, 26 Oct 2015 10:02:48

River conservation and management (1992)

Mon, 26 Oct 2015 10:11:01

The rivers handbook. Hydrological and ecological principles. 1. (1992)

Mon, 26 Oct 2015 10:10:50

La pêche professionnelle fluviale et lacustre en France. Enquête au fil de l'eau (1992)

Mon, 26 Oct 2015 10:10:48

La basse vallée de l'Argens: environnement et gestion (1992)

Mon, 26 Oct 2015 10:09:55

Stream hydrology. An introduction for ecologists (1992)

Mon, 26 Oct 2015 10:09:44

Livre rouge des espèces menacées de poissons d'eau douce de France et bilan des introductions (1992)

Mon, 26 Oct 2015 10:09:12

River water quality ecological assessment and control (1992)

Mon, 26 Oct 2015 10:08:31

Rythmes de dérive des alevins en milieu fluvial. Suivi dans le Rhône au niveau des prises d'eau et influence des vidanges de barrages. 1: Texte. 2: Figures et annexes (1992)

Mon, 26 Oct 2015 10:08:27

Hydroclimate. The influence of water movement on freshwater ecology (1992)

Mon, 26 Oct 2015 10:07:49

The distribution of estuarine macrophytes in relation to freshwater (1992)

Mon, 26 Oct 2015 10:07:14

Effects of substrate, light, and benthic invertebrates on algal drift in small streams (1992)

Mon, 26 Oct 2015 10:06:56

Fisheries. In: Conservation and management of Greek wetlands. GERAKIS P.A. (1992)

Mon, 26 Oct 2015 10:06:02

Ökologische Forderungen an den Hochwasserschutz (1992)

Mon, 26 Oct 2015 10:05:48

Colorimetric determination of sulphate in freshwater with a chromate reagent (1992)

Mon, 26 Oct 2015 10:05:18

Source-sediment controls on the riverine transport of pesticides. In: Conference Crop protection. Pests and diseases. Brighton (GBR) 1992 (1992)

Mon, 26 Oct 2015 10:04:50

Responses of benthic algae to pulses in current and nutrients during simulations of subscouring spates (1992)

Mon, 26 Oct 2015 10:04:48

Vegetation, river management and land use in the Dutch Rhine floodplains (1992)

Mon, 26 Oct 2015 10:04:37

Biogeography of the benthic and intertidal living ostracods (Crustacea) of the Rhône River (1992)

Mon, 26 Oct 2015 10:04:09

Sorption of dissolved organic carbon by hydrous aluminium and iron oxides occurring at the confluence of Deer Creek with the Snake River, Summit County, Colorado (1992)

Mon, 26 Oct 2015 10:04:05

Temporal variation in enrichment effects during periphyton succession in a nitrogen-limited desert stream ecosystem (1992)

Mon, 26 Oct 2015 10:03:40

Control of C, N, P distribution in soils of riparian forests (1992)

Mon, 26 Oct 2015 10:03:37

Some hydrologic effects of urbanization in Catalan rivers (1992)

Mon, 26 Oct 2015 10:03:19

Assessment of habitat of wildlife communities on the Snake River, Jackson, Wyoming (1992)

Mon, 26 Oct 2015 10:03:14

Quel avenir pour la Bassée?. Un enjeu pour l'Ile de France. Une zone d'expansion des crues et un patrimoine naturel à préserver (1992)

Mon, 26 Oct 2015 10:03:12

The diversion of the Evinos River for the water supply of the Attiki Basin. Impact. Alternatives (1992)

Mon, 26 Oct 2015 10:02:49

Environmental factors influencing the prevalence of a cutaneous ulcerative disease (red spot) in the sea mullet, Mugil cephalus L. in the Clarence River, New South Wales, Australia (1992)

Mon, 26 Oct 2015 10:02:47

Levende rivieren (= Living rivers) (1992)

Mon, 26 Oct 2015 10:02:39

Zoogeography of fresh waters. 2. Distribution and dispersal of freshwater animals in North America and Eurasia (1991)

Mon, 26 Oct 2015 10:11:17

Catch effort sampling strategies (1991)

Mon, 26 Oct 2015 10:10:30

Quels fleuves pour demain? Colloque International Orléans (FRA) 23-26/09/1991. Synthèse des débats (1991)

Mon, 26 Oct 2015 10:10:21

Peces continentales espanoles. Inventario y classsificacion de zones fluviales (1991)

Mon, 26 Oct 2015 10:10:13

Etude des mécanismes de transfert de l'argent-110M en eau douce (1991)

Mon, 26 Oct 2015 10:09:52

River projects and conservation. A manual for holistic appraisal (1991)

Mon, 26 Oct 2015 10:09:52

Creating freshwater wetlands (1991)

Mon, 26 Oct 2015 10:09:36

The freshwater fishes of Europe. 2: Clupeidae, Anguillidae (1991)

Mon, 26 Oct 2015 10:09:29

The rivers of Florida (1991)

Mon, 26 Oct 2015 10:08:58

Conservation of threatened freshwater fish in Europe (1991)

Mon, 26 Oct 2015 10:08:55

Battle against extinction. Native fish management in the American West (1991)

Mon, 26 Oct 2015 10:08:40

Volatili (1991)

Mon, 26 Oct 2015 10:08:11

Artificial habitats for marine and freshwater fisheries (1991)

Mon, 26 Oct 2015 10:07:54

Historical and present day management of the River Rhine (1991)

Mon, 26 Oct 2015 10:06:33

Aquaculture in fresh waters. A list of selected reference books and monographs, 1951-1991 (1991)

Mon, 26 Oct 2015 10:06:13

Projet écologique global pour le Rhin " Saumon 2000 " (1991)

Mon, 26 Oct 2015 10:06:08

Juvenile fishes as functional describers of fluvial ecosystem dynamics: Applications on the river Rhône, France (1991)

Mon, 26 Oct 2015 10:06:06

Invertebrates on cut weed removed during weed-cutting operations along an English river, the River Frome, Dorset (1991)

Mon, 26 Oct 2015 10:05:57

Microelectrode measurement of ammonium profiles in freshwater sediments (1991)

Mon, 26 Oct 2015 10:05:57

Evolution de l'impact des retombées de Tchernobyl sur les poissons de rivières, de retenues artificielles et de lacs de montagne corses (1991)

Mon, 26 Oct 2015 10:05:51

Prélèvement et échantillonnage dans les petits bassins-versants ruraux (1991)

Mon, 26 Oct 2015 10:05:46

DNA synthesis and tritiated thymidine incorporation by heterotrophic culture freshwater bacteria in continuous culture (1991)

Mon, 26 Oct 2015 10:05:40

Interprétation d'un site de Loire. Le jardin du dragon: Miciacus (1991)

Mon, 26 Oct 2015 10:05:37

La flore diatomique de quelques cours d'eau de Kisangani (Zaïre) (1991)

Mon, 26 Oct 2015 10:05:19

River basin management in the UK (1991)

Mon, 26 Oct 2015 10:04:50

Incidence des activités de loisirs sur les oiseaux d'eau. Compilation de résultats tirés d'ouvrages spécialisés (1991)

Mon, 26 Oct 2015 10:04:46

The effect of light regime on the photosynthetic apparatus of the freshwater red alga Batrachospermum boryanum (1991)

Mon, 26 Oct 2015 10:04:35

Description of three new species of cyprinid fishes from Sri Lanka. In: Freshwater fishes of Sri Lanka. PETHIYAGODA R. (1991)

Mon, 26 Oct 2015 10:04:26

Données sur les concentrations en plutonium dans l'écosystème aquatique rhodanien en aval de l'usine de Marcoule (1991)

Mon, 26 Oct 2015 10:04:23

Vers une gestion écologique des cours d'eau. Quels enjeux, quels fondements, quels débats pour une nouvelle politique? (1991)

Mon, 26 Oct 2015 10:04:01

Modelling nutrient retention of a freshwater coastal wetland: Estimating the roles of primary productivity, sedimentation, resuspension and hydrology (1991)

Mon, 26 Oct 2015 10:03:58

River basin water quality management in Japan. An overview (1991)

Mon, 26 Oct 2015 10:03:53

Dynamics of littoral fishes and decapods along a coastal river-estuarine gradient (1991)

Mon, 26 Oct 2015 10:03:40

Odonate larvae as an indicator of pesticide contamination (1991)

Mon, 26 Oct 2015 10:03:01

The Des Plaines river wetlands demonstration project: Bibliography (1991)

Mon, 26 Oct 2015 10:02:42

Eaux de Rhône-Méditerranée-Corse (1991)

Mon, 26 Oct 2015 10:02:25

The ecology of freshwater phytoplankton (1990)

Wed, 15 Feb 2023 10:50:05

This book deals with the lifestyle of phytoplankton, the microscopic plant life living in the open waters of ponds, lakes and rivers, with frequent reference to the phytoplankton of the sea. It reviews the adaptations which organisms require to live independently of solid surfaces and the different ways in which this has been achieved.

Régimes et préférences alimentaires d'Anatidés et Scolopacidés dans le delta du Sénégal: (1990)

Fri, 27 Mar 2020 16:42:37

Zoogeography of fresh waters. 1. General distribution and dispersal of freshwater animals (1990)

Mon, 26 Oct 2015 10:11:17

La Loire en sursis. Croisade pour le dernier fleuve sauvage d'Europe (1990)

Mon, 26 Oct 2015 10:10:30

Fishing with electricity. Applications in freshwater fisheries management (1990)

Mon, 26 Oct 2015 10:10:29

River floodplains and policy. A European approach (1990)

Mon, 26 Oct 2015 10:10:23

River floodplains and policy. A European approach (Supplement with complete case studies) (1990)

Mon, 26 Oct 2015 10:10:23

Reproductive seasonality in teleosts: Environmental influences (1990)

Mon, 26 Oct 2015 10:08:34

Wetlands and shallow continental water bodies. 1. Natural and human relationships (1990)

Mon, 26 Oct 2015 10:08:21

Assessment and prediction of biological quality. A demonstration of a Brithish macroinvertebrate-based method in two Spanish rivers (1990)

Mon, 26 Oct 2015 10:07:05

Environmental stability and communities of Chironomidae (Diptera) in a regulated river (1990)

Mon, 26 Oct 2015 10:07:05

Qualita dell'acqua e macroinvertebrati in un ambiente fluviale (1990)

Mon, 26 Oct 2015 10:06:55

Avian profile of the man-modified aquatic ecosystem in the backwaters of the Ujjani dam. A conservation strategy for wetland management of an irrigation project (1990)

Mon, 26 Oct 2015 10:06:46

Ecological characterisation, classification, and modelling of New Zealand rivers: an introduction and synthesis (1990)

Mon, 26 Oct 2015 10:06:45

Trends and seasonality in the nitrate concentrations and loads of the Bere Stream (Dorset) for the period 1966-1986 (1990)

Mon, 26 Oct 2015 10:06:24

Fisheries decline in the freshwater lakes of northern Greece with special attention for Lake Mikri Prespa. In: Management of freshwater fisheries. VAN DENSEN W.L.T., STEINMETZ B. & HUGHES R.H. (1990)

Mon, 26 Oct 2015 10:06:03

Hydrocarbons, sterols, esters and fatty acids in six freshwater chlorophytes (1990)

Mon, 26 Oct 2015 10:06:03

A practical guide to pH measurement in freshwaters (1990)

Mon, 26 Oct 2015 10:05:58

Some remarks on the presence of organic phosphates in sediments (1990)

Mon, 26 Oct 2015 10:05:56

Effects of substrate relief on the distribution of periphyton in laboratory streams. 1. Hydrology (1990)

Mon, 26 Oct 2015 10:05:52

Effects of substrate relief on the distribution of periphyton in laboratory streams. 2. Interactions with irradiance (1990)

Mon, 26 Oct 2015 10:05:52

Caractéristiques physiques et chimiques de quelques cours d'eau de Kisangani (Zaïre) (1990)

Mon, 26 Oct 2015 10:05:19

Ecological classification of the climate of the Rhine catchement (1990)

Mon, 26 Oct 2015 10:04:37

The Eregli marshes (Turkey). Assessment of their biological importance and recommendations for conservation (1990)

Mon, 26 Oct 2015 10:04:29

Méthodes d'évaluation de l'impact radioécologique de l'accident de Tchernobyl sur le fleuve Rhône. In: Environmental contamination following a major nuclear accident. Proceedings of an International Symposium FAO-IAEA-UNEP-WHO Vienna (AUT) 16-20/10/1989 (1990)

Mon, 26 Oct 2015 10:04:23

On a collection of freshwater fishes from Endau-Rompin, Pahang-Johore, Peninsular Malaysia (1990)

Mon, 26 Oct 2015 10:04:15

Transfers between a eutrophic ecosystem, the river Rhône, and an oligotrophic ecosystem, the north-western Mediterranean Sea (1990)

Mon, 26 Oct 2015 10:04:14

Studies of sampling methods and of techniques for estimating populations of eels, Anguilla anguilla L. (1990)

Mon, 26 Oct 2015 10:03:52

Management problems with the differential allocation of fishing rights to sport and commercial fishermen in the Frisian lakes, The Netherlands. In: Management of freshwater fisheries. VAN DENSEN W.L.T., STEINMETZ B. & HUGHES R.H. (1990)

Mon, 26 Oct 2015 10:03:05

Abundance, growth, and diet of channel catfish, Ictalurus punctatus, in the Green and Yampa Rivers, Colorado and Utah (1990)

Mon, 26 Oct 2015 10:02:53

Influence of various exposure periods on the biomass and chlorophyll A of Cladophora glomerata (Chlorophyta) (1990)

Mon, 26 Oct 2015 10:02:51

A la rencontre de la Loire et de l'Allier (1990)

Mon, 26 Oct 2015 10:02:39

Los humedales del acuifero de Madrid. Inventario y tipologia basada en su origen y funcionamiento (1989)

Mon, 26 Oct 2015 10:09:45

The freshwater fishes of Europe. 1. Part 2: General introduction to fishes. Acipenseriformes (1989)

Mon, 26 Oct 2015 10:09:28

Structures assisting the migrations of non-salmonid fish: USSR (1989)

Mon, 26 Oct 2015 10:08:21

Historical change of large alluvial rivers: Western Europe (1989)

Mon, 26 Oct 2015 10:08:18

Biomanipulation in the Netherlands: Applications in fresh-water ecosystems and estuarine waters (1989)

Mon, 26 Oct 2015 10:07:30

Bottomland hardwood reforestation in the Lower Mississippi Valley (1989)

Mon, 26 Oct 2015 10:07:11

Regulated streamflow and warmwater stream fish: A general hypothesis and research agenda (1989)

Mon, 26 Oct 2015 10:07:00

Biomonitoring of organic pollution using periphyton, South Branch, Canterbury, New Zealand (1989)

Mon, 26 Oct 2015 10:06:45

Ecology and management of water plants in lowland streams (1989)

Mon, 26 Oct 2015 10:05:57

Die Vogelwelt der österreichischen Donau (1989)

Mon, 26 Oct 2015 10:05:49

New concept for landscape management and flood control on the Upper Rhine. In: Wetlands and river corridor management (1989)

Mon, 26 Oct 2015 10:05:48

Zur Ökologie und Gefährdung der Loire-Auen (1989)

Mon, 26 Oct 2015 10:05:48

Importance of physical variables on the seasonal dynamics of epilithic Algae in a highly shaded canyon stream (1989)

Mon, 26 Oct 2015 10:05:43

Données sur les transferts du 137 Cs et du 60 Co dans un écosystème fluvial: le Rhône (1989)

Mon, 26 Oct 2015 10:05:30

Stability of periphyton and macroinvertebrata to disturbance by flash floods in a desert stream (1989)

Mon, 26 Oct 2015 10:05:12

Freshwater macrophytes as indicators of organic pollution (1989)

Mon, 26 Oct 2015 10:04:47

Bacterial populations in freshwater sediments: Factors affecting growth and their ultimate fate. In: Recent Advances in Microbial Ecology. Proceedings of the 5th International Symposium on Microbial Ecology ISME 5 (1989)

Mon, 26 Oct 2015 10:04:37

Zoogeography of the fishes from indochinese inland waters with an annoted check-list (1989)

Mon, 26 Oct 2015 10:04:26

Functional assessment of freshwater wetlands: A manual and trainig outline (1989)

Mon, 26 Oct 2015 10:04:22

Effect of long-term flooding on root metabolic response in five freshwater marsh plant species (1989)

Mon, 26 Oct 2015 10:04:05

Etude environnementale d'un site naturel de la vallée du Rhône. Les lones et l'étang de Lamiat-l'Ile Vieille (1989)

Mon, 26 Oct 2015 10:03:59

Herbivory in freshwater fishes: A review (1989)

Mon, 26 Oct 2015 10:03:49

Bedeutung eines Wasservogelbeobachtungsnetzes für eine oberösterreichische Naturhaushalts-Vorsorgestrategie (1989)

Mon, 26 Oct 2015 10:03:39

Entre Saône et Loue, la basse vallée du Doubs (1989)

Mon, 26 Oct 2015 10:03:24

La qualité piscicole de la Semois (1989)

Mon, 26 Oct 2015 10:02:57

Waders and waterfowl in spring 1988 at Eber Golu, Turkey. The importance of freshwater lakes in the western part of Anatolia, Turkey, for migrating waders and waterfowl in spring, with special reference to ruffs (Philomachus pugnans). A case study (1989)

Mon, 26 Oct 2015 10:02:49

Proceedings of a workshop on the development and evaluation of habitat suitability criteria (Colorado state university Fort Collins (USA) 8-12/12/86) (1988)

Mon, 26 Oct 2015 10:10:58

Vegetation of inland waters (1988)

Mon, 26 Oct 2015 10:07:42

Un methodo rapido y simple para evaluar la calidad biologica de las aguas corrientes basado en el de Hellawell (1978) (1988)

Mon, 26 Oct 2015 10:07:12

A peryphyton sampler for shallow, swift rivers (1988)

Mon, 26 Oct 2015 10:06:45

Water pollution in Denmark. A review with special reference to freshwater resources (1988)

Mon, 26 Oct 2015 10:05:59

Die Modell-Auen (1988)

Mon, 26 Oct 2015 10:05:48

The inland fisheries of Israel (1988)

Mon, 26 Oct 2015 10:05:48

Ökologie der mitteleuropäischen Auenwälder (1988)

Mon, 26 Oct 2015 10:05:48

Bedrohte Tier- und Pflanzenwelt an der mittleren Save (Jugoslawien) und die Bestrebungen zu ihrer Erhaltung (1988)

Mon, 26 Oct 2015 10:05:39

Effects of cadmium exposure on feeding of freshwater planktonic crustaceans (1988)

Mon, 26 Oct 2015 10:05:09

Freshwater carbon and the weathering cycle. In: Physical and chemical weathering in geochemical cycles. LERMAN A. & MEYBECK M. (1988)

Mon, 26 Oct 2015 10:04:30

Austropotamobius pallipes and A.torrentium, with observations on their interactions with other species in Europe In: Freshwater crayfish, biology, management and exploitation. HOLDICH D.M. & LOWERY R.S. (1988)

Mon, 26 Oct 2015 10:04:21

Fluctuations in trout populations and their implications for land-use evaluation (1988)

Mon, 26 Oct 2015 10:03:36

Les plaines alluviales du Rhin superieur. Ecologie et gestion = Auen am Oberrhein. Okologie und Management (1988)

Mon, 26 Oct 2015 10:03:28

Algal communities of continental waters. In: Vegetation of inland waters. SYMOENS J.J. (1988)

Mon, 26 Oct 2015 10:03:02

Donau-Auen: Nationalpark oder Kraftwerk. Eine Informationsschrift der Nationalparkplanung Donau-Auen (1988)

Mon, 26 Oct 2015 10:02:45

Ecosystèmes d'eau courante du haut Sebou (Moyen Atlas): Etudes typologiques et analyses écologique et biogéographique des principaux peuplements entomologiques (1987)

Mon, 26 Oct 2015 10:10:26

Physical processes, ecological dynamics, and management implications. Results of research in the Atchafalaya delta region (1987)

Mon, 26 Oct 2015 10:10:24

Les éléments nutritifs du Rhône: leur devenir dans les canaux d'irrigation et les marais en Camargue (1987)

Mon, 26 Oct 2015 10:10:06

River plants of western Europe. The macrophytic vegetation of water courses of the European Economic Community (1987)

Mon, 26 Oct 2015 10:09:34

The freshwater fishes of Europe. 9: Threatened fishes of Europe (1987)

Mon, 26 Oct 2015 10:09:00

Environnement et aménagement d'un cours d'eau méditerranéen. Etude de cas: Les Gardons (1987)

Mon, 26 Oct 2015 10:08:51

Applications aux grandes rivières d'un indice de qualité biologique basé sur les macroinvertébrés benthiques (1987)

Mon, 26 Oct 2015 10:06:22

Effects of salinity and temperature on oxygen consumption in a freshwater population of Palaemonetes antennarius (Crustacea, Decapoda) (1987)

Mon, 26 Oct 2015 10:05:59

Salinity responses in brackish water populations of the freshwater shrimp Palaemonetes antennarius. 1: Oxygen consumption (1987)

Mon, 26 Oct 2015 10:05:59

Input of nutrients and suspended matter into the Golfe du Lion and the Camargue by the river Rhone = Apport par le Rhône de nutriments et de matières en suspension dans le Golfe du Lion et la Camargue (1987)

Mon, 26 Oct 2015 10:05:41

Input of nutrients and suspended matter into the Golfe du Lion by the river Rhône. In: Environmental pollution and its impact on life in the Mediterranean Region 1985. HERRMANN M., KOTZIAS D. & PARLAR H. (1987)

Mon, 26 Oct 2015 10:05:41

Le phosphate du Rhône et son déchargement dans le Golfe du Lion (1987)

Mon, 26 Oct 2015 10:05:41

Ontogeny of growth, respiration and feeding rate of the freshwater calanoid copepod Eudiaptomus graciloides (1987)

Mon, 26 Oct 2015 10:05:06

Predictability in lake ecosystems: The role of biotic interactions. In: Ecological studies vol 61. SCHULZE E.D. & ZWOLFER H. (1987)

Mon, 26 Oct 2015 10:04:23

Bird predation on hatchery reared atlantic salmon smolts, Salmo salar L., released in the River Eira, Norway (1987)

Mon, 26 Oct 2015 10:03:28

Feeding behaviour of wild atlantic salmon, Salmo salar L. parr in mid- to late summer in a Scottish river (1987)

Mon, 26 Oct 2015 10:03:04

Interaction entre les activités humaines et l'écosystème des eaux courantes à saumon atlantique; étude de deux bassins versants en Bretagne (Scorff, Morbihan et Trieux, Côtes du nord) depuis 1950 (1987)

Mon, 26 Oct 2015 10:02:58

Guidelines for determining river inputs of inorganic contaminants into estuaries (1987)

Mon, 26 Oct 2015 10:02:52

The freshwater fishes of Europe. 1. Part 1: Petromyzontiformes (1986)

Mon, 26 Oct 2015 10:09:28

Recherches sur la faunistique, l'écologie et la zoogéographie de trois réseaux hydrographiques du Liban: l'Assi, le Litani et le Beyrouth (1986)

Mon, 26 Oct 2015 10:08:36

Uber die Altersstruktur einiger ausgewahlter Fischarten und die Nahrungswahl der Asche (Thymallus thymallus L.) am mittleren Kamp (Niederösterreich) (1986)

Mon, 26 Oct 2015 10:05:49

Hochwasserschutzmassnahmen am Oberrhein (1986)

Mon, 26 Oct 2015 10:05:48

Causes of changes in river vegetation giving rise to complaints. In: Proceedings EWRS/AAB 7 Symposium on aquatic weeds 1986 (1986)

Mon, 26 Oct 2015 10:05:04

Factors controlling the secondary productivity of benthic macroinvertebrates in freshwaters: A review (1986)

Mon, 26 Oct 2015 10:04:43

Examination of the generality of eutrophication models (1986)

Mon, 26 Oct 2015 10:04:36

Validation of a prognosis based upon a eutrophication model (1986)

Mon, 26 Oct 2015 10:04:36

Aquatic plants of the Amazon system. In: The ecology of river systems. DAVIES B.R. & WALKER K.F. (1986)

Mon, 26 Oct 2015 10:04:35

Biotoxines aquatiques (eau de mer et eau douce) (1986)

Mon, 26 Oct 2015 10:03:47

Effects of experimental acidification on freshwater environments (1986)

Mon, 26 Oct 2015 10:03:29

The effects of freshwater diversion on the fisheries, flushing and health of San Francisco Bay and the Sea of Azov (1986)

Mon, 26 Oct 2015 10:03:21

Le marquage des tortues d'eau douce: Application à la cistude d'Europe Emys orbicularis (Reptilia, Chelonii) (1986)

Mon, 26 Oct 2015 10:03:13

Establishment of a bedrock epilithic community in a small stream: microbial (algal and bacterial) metabolism and physical structure (1986)

Mon, 26 Oct 2015 10:03:04

Intérêt écologique et fragilité des zones humides des Landes de Gascogne (1985)

Mon, 26 Oct 2015 10:09:40

Lake Balaton. Research and management (1985)

Mon, 26 Oct 2015 10:08:39

La biocénose aquatique et ses incidences sur le peuplement piscicole (1985)

Mon, 26 Oct 2015 10:06:58

Channel form and stream ecosystem models (1985)

Mon, 26 Oct 2015 10:06:31

Fischbestandserhebungen an zwei Fliesswasserstrecken des Kamp (Niederösterreich) unter Berücksichtigung der ökologischen Verhältnisse (1985)

Mon, 26 Oct 2015 10:05:49

Hydrogeochemistry of amazonian freshwaters along Transamazonica in Brazil (1985)

Mon, 26 Oct 2015 10:05:27

Les fluctuations dans les populations de poissons d'eau douce. Conséquences sur les études écologiques (1985)

Mon, 26 Oct 2015 10:05:22

The geochemistry of the Rhine and the Rhone. 5. Synthesis and conclusions (1985)

Mon, 26 Oct 2015 10:05:18

The geochemistry of two hard water rivers the Rhine and the Rhone. 1. Presentation and screening of the data (1985)

Mon, 26 Oct 2015 10:05:17

The geochemistry of two hard water rivers the Rhine and the Rhone. 2. The apparent solubility of calcium carbonate (1985)

Mon, 26 Oct 2015 10:05:17

The geochemistry of two hard water rivers the Rhine and the Rhone. 3. The relation between calcium, bicarbonate, sulphate and pH (1985)

Mon, 26 Oct 2015 10:05:17

The geochemistry of two hard water rivers the Rhine and the Rhone. 4. The determination of the solubility product of hydroxy-apatite (1985)

Mon, 26 Oct 2015 10:05:17

Kinetic studies of bacterial sulfate reduction in freshwater sediments by high pressure liquid chromatography and microdistillation (1985)

Mon, 26 Oct 2015 10:04:50

The physical and chemical properties of amazonian waters and their relationships with the biota. In: Key environments: Amazonia. PRANCE G.T. & LOVEJOY T.E. (1985)

Mon, 26 Oct 2015 10:04:35

La flore diatomique des rivières de la plaine de la Rusizi au Burundi (1985)

Mon, 26 Oct 2015 10:03:54

Relationships of seed banks to plant distribution patterns in a freshwater tidal wetland (1985)

Mon, 26 Oct 2015 10:03:43

Guida al riconoscimento dei ciottoli sui ghiareti del Po (1985)

Mon, 26 Oct 2015 10:03:38

Some aspects of freshwater acidification. In: International Congress Proceedings: Lakes pollution and recovery Rome (ITA) 15-18/04/1985 (1985)

Mon, 26 Oct 2015 10:03:29

Potential importance of fish predation and zooplankton grazing on natural populations of freshwater bacteria (1985)

Mon, 26 Oct 2015 10:03:25

The ecology of freshwater phytoplankton (1984)

Mon, 4 Apr 2022 10:25:47

Impact de la géochimie du Rhône sur la Camargue (Bouches du Rhône, France): étude des nutriments (phosphate, azote et carbone) dans des sols de Camargue et dans le Rhône (1984)

Mon, 26 Oct 2015 10:10:06

Environmental changes induced by stream regulation and their effect on lotic macroinvertebrate communities. In: Regulated rivers. LILLEHAMER A. & SALTVEIT S.J. (1984)

Mon, 26 Oct 2015 10:07:05

Les ressources alimentaires naturelles des poissons d'étangs (1984)

Mon, 26 Oct 2015 10:06:59

Computation of flow patterns in rivers (1984)

Mon, 26 Oct 2015 10:06:38

Variation of flow resistance through curved channel (1984)

Mon, 26 Oct 2015 10:06:19

Fleuves sources de vie (1984)

Mon, 26 Oct 2015 10:06:04

Zur ökologischen Problematik der geplanten Donau-Staustufe bei Hainburg/Niederösterreich (1984)

Mon, 26 Oct 2015 10:05:48

Denitrification associated with stream periphyton. Chamber estimates from undisrupted communities (1984)

Mon, 26 Oct 2015 10:05:44

Principles and practice of stocking streams with salmon eggs and fry (1984)

Mon, 26 Oct 2015 10:05:41

Ricerche sullo zooplancton estivo nel tratto medio del fiume Po. In: Contributi di ecologia fondamentale. MORONI A. (1984)

Mon, 26 Oct 2015 10:05:34

Comparison of three methods for sampling fishes and macroinvertebrates in a vegetated freshwater wetland (1984)

Mon, 26 Oct 2015 10:05:29

Water chemistry of the Amazon basin. The distribution of chemical elements among freshwaters. In: The Amazon. Limnology and landscape ecology of a mighty tropical river and its basin. SIOLI H. (1984)

Mon, 26 Oct 2015 10:05:27

Sediments, modifying and equilibrating factors in the chemistry of freshwaters (1984)

Mon, 26 Oct 2015 10:05:18

Periphyton colonization of rock surfaces in a boreal forest stream studied by scanning electron microscopy and track autoradiography (1984)

Mon, 26 Oct 2015 10:05:06

Relationship of young-of-the-year northern pike to aquatic vegetation types in backwaters of the Upper Mississipi River (1984)

Mon, 26 Oct 2015 10:04:52

Measure of microbial turnover of carbon in anoxic freshwater sediments: cautionary comments (1984)

Mon, 26 Oct 2015 10:04:37

The presence and activity of Desulfotomaculum spp in sulphate limited freshwater sediments (1984)

Mon, 26 Oct 2015 10:04:37

A method for measuring stream flows in rivers (1984)

Mon, 26 Oct 2015 10:04:27

Manganese chemistry in rivers and streams (1984)

Mon, 26 Oct 2015 10:04:21

Response of channel flow to roughness heterogeneity (1984)

Mon, 26 Oct 2015 10:03:52

Microbiology of Amazonian waters. In: The Amazon. Limnology and landscape ecology of a mighty tropical river and its basin. SIOLI H. (1984)

Mon, 26 Oct 2015 10:03:30

Primary production in the Amazonian aquatic ecosystem. In: The Amazon. Limnology and landscape ecology of a mighty tropical river and its basin. SIOLI H. (1984)

Mon, 26 Oct 2015 10:03:30

Cadmium in freshwater ecosystems (1984)

Mon, 26 Oct 2015 10:03:29

A model for flow in meandering flow (1984)

Mon, 26 Oct 2015 10:03:07

Conservation and resource management studies of freshwater ecosystems including river Ganga in Varanasi district. Second annual report (2 sept 1982-1 sept 1983) (1983)

Mon, 26 Oct 2015 10:07:08

The water quality and benthic biology of the Waimakariri River and tributaries. A summary (1983)

Mon, 26 Oct 2015 10:06:45

The management of river vegetation with particular reference to shading effects of marginal vegetation (1983)

Mon, 26 Oct 2015 10:05:57

Ökosystemforschung an einem Mittelgebirgsbach (Emergenzanalyse) (1983)

Mon, 26 Oct 2015 10:04:46

Stock enhancement in the management of freshwater fisheries. A european perspective (1983)

Mon, 26 Oct 2015 10:02:43

Variability in sinking rate of the freshwater diatom Asterionella formosa Hass. The influence of the excess density of colonies (1983)

Mon, 26 Oct 2015 10:02:41

Conservation of Species of Wild Flora and Vertebrate Fauna Threatened in the Community. Volume 1 (1982)

Wed, 15 Feb 2023 10:50:09

Ecologie et utilisation des eaux continentales africaines (1982)

Mon, 26 Oct 2015 10:07:41

Etude des biocénoses des mares et ruisseaux temporaires à éphémérophytes dominants en région méditerranéenne française (1982)

Mon, 26 Oct 2015 10:06:58

Diet of the Australian freshwater turtle Emydura krefftii (Chelonia: Chelidae), in an unproductive lentic environment (1982)

Mon, 26 Oct 2015 10:05:22

La géochimie du Rhin et du Rhône et l'impact humain (1982)

Mon, 26 Oct 2015 10:05:18

Le Rhin et le Rhône sont deux fleuves qui se ressemblent beaucoup en ce qui concerne leur caractéristiques géologiques, hydrologiques et géochimiques. Tous deux prennent naissance dans des glaciers contigus en Suisse, passent chacun une région calcaire, traversent un lac profond qui retient la plus grande partie de la vase glaciaire, et continuent sur environ 1 000 km, prenant de plus en plus le caractère de fleuves à régime pluvial. Originellement la chimie des eaux et de la matière en suspension était identique. Toutefois l'impact de la civilisation a été different dans les deux cas. Il est proposé qu'une description détaillée des deux systèmes fluviaux devrait aider à comprendre et réduire la pollution actuelle; probablement les deux fleuves pourront en quelque mesure fournir des données de base entre eux pour les éléments constituants différents.

The measurement of photosynthetic pigments in freshwaters and standardization of methods (1982)

Mon, 26 Oct 2015 10:05:06

Endohelminti jegulje (Anguilla anguilla Linne, 1758) skadarskog jezera i nekih pritoka = The endohelminths of eel (Anguilla anguilla Linne, 1758) of Lake Skadar and some tributaries (1982)

Mon, 26 Oct 2015 10:04:31

Zum Lebensformtypus Gammarus und dessen Indikationswert für Fliegewasserschäden (1982)

Mon, 26 Oct 2015 10:04:04

Models of the O2 and CO2 regimes in shallow ponds. In: Proceedings of the International Scientific Workshop on Ecosystems dynamics in freshwaters wetlands and shallow water bodies Moscow (SUN) 1982. SCIENTIFIC COMMITTEE ON PROBLEMS ON THE ENVIRONMENT SCOPE (1982)

Mon, 26 Oct 2015 10:03:47

The function of predatory fish in ecosystem (1982)

Mon, 26 Oct 2015 10:03:34

Thirty year of weed cutting on a chalk-stream. In: Proceedings EWRS 6th Symposium on aquatic weeds 1982 (1982)

Mon, 26 Oct 2015 10:02:42

Recherches écologiques sur les milieux aquatiques temporaires peu profonds (1981)

Wed, 19 Jun 2019 16:10:26

Définition des paramètres physiques et chimiques du milieu; caractéristiques liées a la culture, lumière et température, paramètres physiques et chimiques. La flore algale. Les facteurs du développement

Contribution à la dynamique des populations d'oiseaux : modèles mathématiques en temps discret (1981)

Wed, 16 Nov 2016 17:07:24

Les processus de ramification sous leur forme la plus generale constituent un cadre efficace de construction de modeles en dynamique des populations, aussi bien empiriques que theoriques en ce qui concerne les oiseaux. Le concept d'effectif a l'equilibre a une valeur beaucoup plus generale que celui de capacite brute du milieu. La variabilite inter-habitat et les mecanismes de dispersion qu'elle engendre constituent chez les mouettes un mecanisme important de regulation. L'etude des relations entre longevite et masse corporelle permet de distinguer une composante allometrique et une composante non-allometrique dans les strategies demographiques

Les aloses des fleuves français Alosa fallax Lacépède, 1803 et Alosa alosa Linné, 1758. Biométrie, écobiologie: anatomie des populations (1981)

Mon, 26 Oct 2015 10:10:12

Critères de qualité des eaux pour les poissons d'eau douce européens. Rapport sur les effets produits par la combinaison de toxiques dans l'eau sur les poissons d'eau douce et sur d'autres formes de vie aquatique (1981)

Mon, 26 Oct 2015 10:09:58

Le phytoplancton de l'Etang de Berre. Composition spécifique, biomasse et production; relations avec les facteurs hydrologiques, les cours d'eau afférents et le milieu marin voisin (Méditerranée nord-occidentale) (1981)

Mon, 26 Oct 2015 10:09:11

Turbellariés triclades paludicoles (planaires d'eau douce) (1981)

Mon, 26 Oct 2015 10:08:21

Travaux sur la taxonomie, la biologie et l'écologie d'insectes torrenticoles du sud-ouest de la France (Ephémèroptères et Diptères: Dixidae, Cecidomyiidae, Rhagionidae et Athericidae), avec quelques exemples de perturbations par l'homme (1981)

Mon, 26 Oct 2015 10:07:38

Le black-bass, Micropterus salmoides (Lacep.), dans les eaux italiennes. Un antagoniste du brochet ? (1981)

Mon, 26 Oct 2015 10:07:11

Osmoregulation ability and juvenile habitat preference in some penaeid prawns (1981)

Mon, 26 Oct 2015 10:05:59

The rainpool ecosystems of Israel: Geographical distribution of freshwater Anostraca (Crustacea) (1981)

Mon, 26 Oct 2015 10:05:48

The fate of fenitrothion in a stream environment and its effect of the fauna, following aerial spraying of a scottish forest (1981)

Mon, 26 Oct 2015 10:03:55

Experimental studies of decapod and fish predation on seagrass macrobenthos (1981)

Mon, 26 Oct 2015 10:03:51

The Warmwater Streams Symposium. A National Symposium on Fisheries Aspects of Warmwater Streams. Proceedings of a Symposium Held at the University of Tennessee, Knoxville 9-11 March 1980 (1981)

Mon, 26 Oct 2015 10:02:33

Guidelines for sampling fish in inland waters (1980)

Mon, 26 Oct 2015 10:11:20

Distribution and abundance of submersed aquatic vegetation in the tidal Potomac River. Implications for waterfowl (1980)

Mon, 26 Oct 2015 10:06:24

Bemerkungen zur Ökologie und soziologischen Stellung der Auenwälder am nordlichen Oberrhein (Hessische Rheinaue) (1980)

Mon, 26 Oct 2015 10:05:48

Feeding of freshwater filter-feeders at very low food concentrations: Poor evidence for "threshold feeding" and "optimal foraging" in Daphnia longispina and Eudiaptomus gracilis (1980)

Mon, 26 Oct 2015 10:03:54

Impact of water level changes on woody riparian and wetlands communities. 8: Pacific Northwest and rocky mountain regions (1980)

Mon, 26 Oct 2015 10:02:44

Production of Eudiaptomus intermedius in lake Santo Parmense (1979)

Mon, 26 Oct 2015 10:07:04

Experimental studies on macroinvertebrate predator-prey impact of pesticides. The reactions of Rhyacophila and Hydropsyche (Trichoptera) larvae to Simulium larvicides (1979)

Mon, 26 Oct 2015 10:03:54

Observations des populations aviaires et en particulier des sternes pierregarin (Sterna hirundo L.) et naine (Sterna albifrons Pall.) d'un méandre de la Loire en amont d'Orléans, en rapport avec les variations de niveau du fleuve (1979)

Mon, 26 Oct 2015 10:03:53

Une nouvelle méthode d'étude des peuplements ichtyologiques dans les grands cours d'eau par échantillonnage ponctuel d'abondance (1979)

Mon, 26 Oct 2015 10:03:51

River plants. The macrophytic vegetation of watercourses (1978)

Mon, 26 Oct 2015 10:09:34

The seasonal effects of aquatic plant growth on the flow of water in a stream. In: Proceedings EWRS 5th Symposium on Aquatic Weeds 1978 (1978)

Mon, 26 Oct 2015 10:05:57

Ricerche su fitoplancton e fitobentos in un lago di montagna, il lago Santo Parmense (1978)

Mon, 26 Oct 2015 10:05:34

Nuisance aquatic macrophyte growth (1978)

Mon, 26 Oct 2015 10:04:58

The standing crop of aquatic plants of lowland streams in Denmark and the inter-relationships of nutrients in plant, sediment and water. In: Proceedings EWRS 5th Symposium on Aquatic Weeds 1978 (1978)

Mon, 26 Oct 2015 10:04:29

An index to the publications of the staff of the Freshwater Institute, Winnipeg, 1976-77 (1978)

Mon, 26 Oct 2015 10:04:08

Regional meeting on integrated ecological research and training needs in North East Africa and in the Near and Middle East, with emphasis on the ecological effects of irrigation derived from large river basins. Final report. Alexandria (EGY) 24-27/02/1976 (1978)

Mon, 26 Oct 2015 10:02:52

Macrophytes of the river Wear: 1966-1976 (1977)

Mon, 26 Oct 2015 10:04:51

Influence sur les populations de poissons des aménagements hydrauliques de petits cours d'eau assez rapides (1976)

Thu, 14 May 2020 00:00:00

Hydrométrie pratique des cours d'eau (1976)

Mon, 26 Oct 2015 10:11:26

L'écologie contre les nuisances pour la conservation de la nature (1976)

Mon, 26 Oct 2015 10:11:21

An index to the publications of the staff of the Freshwater Institute, Winnipeg, 1974-75 (1976)

Mon, 26 Oct 2015 10:04:09

Aspects de la biologie de l'alose du Rhone, peche et difficultes croissantes de ses migrations (1976)

Mon, 26 Oct 2015 10:03:30

Evaluation models for public management of freshwater wetlands (1975)

Thu, 14 May 2020 00:00:00

Distribution of fishes in the Dolores and Yampa River systems of the Upper Colorado Basin (1975)

Mon, 26 Oct 2015 10:04:52

Macrophytes of the river Tweed (1975)

Mon, 26 Oct 2015 10:04:51

Notes on some macroscopic Algae new or seldom recorded for Britain: Nostoc parmelioides, Heribaudiella fluviatilis, Cladophora aegagropila, Monostroma bullosum, Rhodoplax schinzii (1975)

Mon, 26 Oct 2015 10:04:51

Submerged Bryophytes and Angiosperms of the river Tweed and its tributaries (1975)

Mon, 26 Oct 2015 10:04:51

Aquatic weed control policy. In: Proceedings 28th New Zealand Weed and Pest Control Conference (1975)

Mon, 26 Oct 2015 10:04:48

An index to the publications of the staff of the Freshwater Institute, Winnipeg; the Biological Station and Technological Unit, London; and the Central Biological Station, Winnipeg; 1944-1973 (1975)

Mon, 26 Oct 2015 10:04:09

Vegetation survey of the Tarawera river and environs, North Island, New Zealand (1975)

Mon, 26 Oct 2015 10:03:58

Studies of the eel Anguilla anguilla in Ireland. 4. In the Munster Blackwater river (1975)

Mon, 26 Oct 2015 10:03:55

Reproduction of the mosquitofish (Gambusia affinis affinis), a freshwater fish introduced into Japan (1974)

Mon, 11 Mar 2019 00:00:00

Taxonomic position, distribution and biology of the gobies present in the Italian freshwaters, Padogobius martensi (Günther) and Gobius nigricans Canestrini (Osteichthyes, Gobiidae) (1974)

Mon, 26 Oct 2015 10:05:26

Studies of the eel Anguilla anguilla in Ireland. 3. In the Shannon catchment (1974)

Mon, 26 Oct 2015 10:03:55

The age and growth of pike Esox lucius from four Irish trout rivers (1973)

Mon, 26 Oct 2015 10:06:35

Problems of the conservation of freshwater ecosystems (1972)

Thu, 14 May 2020 00:00:00

Some aspects of the biology of gudgeon Gobio gobio (L.) in Irish waters (1972)

Mon, 26 Oct 2015 10:04:30

Description of structure and forming of the annual cycle of water bodies located in the temperate zone. In: The lakes of the karelian isthmus: The limnological cycles of lake Krasnyi. ? (1972)

Mon, 26 Oct 2015 10:03:50

Physical factors and some river weeds. In: Proceedings Eur Weed Res Coun 3rd International Symposium on Aquatic Weeds 1971 (1971)

Mon, 26 Oct 2015 10:05:01

Contribution of young fish to total production of fish in the River Thames near Reading (1971)

Mon, 26 Oct 2015 10:04:07

Antarctic ecology. Volume 1 & 2 (1970)

Mon, 26 Oct 2015 10:09:28

Wissenschaftliche Expedition des Berner Hirnanatomischen Institutes nach Westpakistan und Assam im Jahre 1969 zur Erforschung des Gangesdelphins (Platanista gangetica) (1970)

Mon, 26 Oct 2015 10:03:37

Ecologia del plancton d'acqua dolce (1970)

Mon, 26 Oct 2015 10:03:29

Some birds of the Lower Chobe River area, Bostwana (1969)

Mon, 26 Oct 2015 10:04:45

Notes on a collection of birds from the Khwae River in Bostwana (1969)

Mon, 26 Oct 2015 10:04:43

Flora de las aguas continentales espanolas (1968)

Mon, 26 Oct 2015 10:08:03

Etude comparative de poissons téléostéens des genres Leucaspius et Phoxinellus (Pararhodeus) récoltés dans les eaux douces françaises et grecques (1967)

Mon, 26 Oct 2015 10:03:06

Emergence of Chironomidae (Diptera) from continental water bodies of different climatic zones as a factor determining the food supply of fish (1963)

Mon, 26 Oct 2015 10:06:38

Studies on freshwater Entomostraca in Greenland. localities, ecology, and geographical distribution of the species (1962)

Thu, 17 Feb 2022 09:23:45

Freswater fishes of the world (1962)

Mon, 26 Oct 2015 10:07:45

Recherches écologiques et biologiques sur les crustacés de deux mares temporaires (1961)

Thu, 14 May 2020 00:00:00

Recherches biologiques sur les populations de Gobio gobio (Linné 1758) de La Nivelle (fleuve côtier du Pays Basque) (1960)

Mon, 26 Oct 2015 10:06:48

A freshwater pond in New Zealand (1960)

Mon, 26 Oct 2015 10:06:29

Destruction and re-establishment of stream fish and invertebrates affected by drought (1959)

Mon, 26 Oct 2015 10:04:22

De l'influence, sur les algues d'eau douce, des produits de décomposition spontanée des substances organiques d'origine animale et végétale (1958-04-01)

Thu, 27 Dec 2018 00:00:00

Preliminary observations on the oxygen uptake by some freshwater zooplankters (1958)

Mon, 26 Oct 2015 10:02:46

Notes on Freshwater Algae, Mainly from Lochs in Perthshire and Sutherland (January 1, 1957)

Mon, 8 Oct 2018 00:00:00

Cinq années d'algologie d'eau douce (1950–1954)

Thu, 22 May 2025 13:42:50

Amount of mud displaced by some freshwater Oligochaeta in relation to depth (1955)

Mon, 26 Oct 2015 10:03:29

Poissons et crustacés d'eau douce acclimatés en France en eaux libres depuis le début du siècle (1951)

Mon, 26 Oct 2015 10:02:47

Methods of collecting freshwater turtles (1943)

Mon, 26 Oct 2015 10:04:24

Report of the committe on fish-passes (1942)

Mon, 26 Oct 2015 10:04:46

Particularités de la distribution de l'ichthyofaune des eaux douces de la Grèce (1935)

Mon, 26 Oct 2015 10:07:03

Studies on the ecology of rivers. On the distribution of macrophytic vegetation in the rivers of Britain (1933)

Mon, 26 Oct 2015 10:06:29

Sur quelques poissons d'eau douce d'Albanie (1930)

Mon, 26 Oct 2015 10:02:47

A preliminary account of the vegetation of the river Itchen (1927)

Mon, 26 Oct 2015 10:06:29

Jeunes stades d'eau douce et biologie de la lamproie marine (1920)

Mon, 26 Oct 2015 10:04:18

The naturalist on the river Amazons (1910)

Mon, 26 Oct 2015 10:11:13

Sur la dissémination des organismes d'eau douce par les palmipèdes (1888)

Mon, 26 Oct 2015 10:05:55

River and sea: foraging range of freshwater and marine Common Terns

Thu, 6 Mar 2025 15:53:59

The foraging ranges of breeding seabirds differ between species and colonies, depending on species locomotion traits, food availability, environmental characteristics, and social factors. The Common Tern (Sterna hirundo) is a generalist seabird that breeds and forages in a wide variety of habitats in both freshwater and marine environments. Using GPS loggers, we compared the foraging range, foraging patterns, and the colony attendance of Common Terns from freshwater and marine colonies during the incubation and chick-rearing periods. Common Terns from freshwater colonies foraged at lower distances from colonies and had higher daily colony attendance than conspecifics from marine colonies in the Adriatic Sea. Maximum distance to the colony and 50% and 95% utilisation distributions were higher during the chick-rearing phase. Colony attendance was higher during the incubation and among females. Compared to freshwater terns, marine birds foraged later in the evening. Freshwater terns mainly foraged along rivers but also visited smaller lakes. Terns from marine populations were not recorded to forage in freshwater sites within the foraging range. Tracking studies with finer temporal scale and detailed spatio-temporal data on wind and tide dynamics are needed to understand environmental factors affecting foraging dynamics of Common Terns in the Adriatic Sea.

Les cours d'eau temporaires du massif des Maures: Hydrologie, hydrochimie, communautés algales et animales

Fri, 24 Mar 2023 18:41:51

Freshwater Crayfish

Thu, 14 May 2020 11:28:20

Institute of Freshwater Research

Thu, 14 May 2020 11:27:45

La pêche du "Zompona" ; la pêche aux anguilles au lac Alaotra et au lac Itasy ([19..])

Thu, 14 May 2020 00:00:00

Extended primary moult as an adaptation of adult Wood Sandpipers Tringa glareola to their freshwater habitats in southern Africa

Wed, 13 Nov 2019 09:49:12

Migrant waders using freshwater habitats are hypothesized to have slower primary moult than waders using coastal habitats. We chose the Wood Sandpiper Tringa glareola as a representative species using the freshwater habitats and compare its moult pattern with a range of fresh-water and coastal wader species to test the habitat hypothesis. Only fragmentary descriptions of Wood Sandpipers' primary moult in their sub-Saharan non-breeding quarters had existed. We analysed the primary moult formulae of 1496 adult Wood Sandpipers obtained in southern Africa. The Underhill & Zucchini moult model was used to estimate the timing and duration of moult for all 10 primaries combined and for each primary individually. We also estimated the rate of production of feather material during moult. Adult Wood Sandpipers arrive in southern Africa between late July and November, and depart from mid-March to April. Suspension of moult was observed in 56 birds (7.5%) after two to nine primaries had been replaced. The remaining birds performed a continuous complete primary moult, with average start and completion dates of 21 August and 30 December, respectively; estimated duration was 131 days. The overall rate of production of primary feather material was uniform, achieved by growing up to five small inner primaries simultaneously at the beginning of the moult but only one or two simultaneously while the large outer primaries were growing. Primary moult of adult Wood Sandpipers took longer but ended earlier than in similar-sized waders using coastal habitats. Compared with waders using coastal habitats, Wood Sandpipers prolonged moult by shedding their primaries at longer intervals and by extending the growth period of each primary. The longer primary moult and its earlier ending compared with coastal waders are probably adaptations to Wood Sandpipers' use of freshwater habitats, which in southern Africa provide unpredictable food supplies and might require nomadic movements between ephemeral inland wetlands.

New Zealand Journal of Marine and Freshwater Research

Tue, 16 Jul 2019 14:08:26

Status, trends, and future dynamics of freshwater ecosystems in Europe and Central Asia

Tue, 29 Jan 2019 10:49:36

This review is part of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) report on Europe and Central Asia (ECA) and provides a critical assessment of issues facing decision-makers, including freshwater biodiversity and ecosystem trends as well as drivers of change. Freshwater systems are well established as the most threatened ecosystem type in the ECA region, with the quantity and quality of habitats and abundance of many species rapidly declining. Only about half (53%) of the EU's rivers and lakes achieved good ecological status in 2015 (as defined by the Water Framework Directive in terms of the quality of the biological community), and many lakes, ponds, and streams are disappearing as a consequence of agricultural intensification and inefficient irrigation and urbanisation, combined with climate change. The situation regarding freshwater biodiversity remains highly critical in ECA as many species remain threatened with extinction, including >50% of known species for some groups (e.g., molluscs, amphibians). Drivers of ECA freshwater taxa include the destruction or modification of their habitat, including water abstraction, which affects ∼89% of all amphibian threatened species and ∼26% of threatened freshwater invertebrate species. Of particular concern is the lack of data for freshwater invertebrates. Current status is available for only a minority of species, and the impact of alien invasive species is often unknown, especially in Central Asia. Based on current freshwater biodiversity trends, it is highly unlikely that ECA will achieve either the respective Aichi biodiversity targets by 2020 (i.e., targets 2 to 4, 6 to 12, and 14) or Target 1 of the Biodiversity Strategy.

History and conservation of Tunisia's largest freshwater wetland: Garâa Sejenane

Wed, 4 Jul 2018 16:08:44

Identifying priority sites for the conservation of freshwater fish biodiversity in a Mediterranean basin with a high degree of threatened endemics

Fri, 8 Jun 2018 14:51:59

The Guadiana River basin's freshwater fish species richness, endemicity and threatened status (92% of native species are threatened) highlight the need for a large-scale study to identify priority areas for their conservation. One of the most common problems in conservation planning is the assessment of a site's relative value for the conservation of regional biodiversity. Here we used a two-tiered approach, which integrates an assessment of biodiversity loss and the evaluation of conservation value through site-specific measures. These measures based on the reference condition approach introduce the ability to make objective comparisons throughout the Guadiana River basin, thus avoiding a priori target areas. We identified a set of biodiversity priority areas of special conservation significance-which contain rare taxa as well as intact fish communities-because of their outstanding contribution to the basin's biodiversity. The inclusion of complete sub-basins in these priority areas might guarantee an optimal solution in terms of spatial aggregation and connectivity. However, the high spatial fragmentation to which the Guadiana River basin is submitted due to river regulation highlights the necessity of a systematic approach to evaluate the capability of the identified priority areas to maintain the Guadiana's freshwater fish biodiversity.

Density-dependent and inter-specific interactions affecting European eel settlement in freshwater habitats

Fri, 8 Jun 2018 14:50:49

Identifying the factors influencing the settlement of European eel (Anguilla anguilla) juveniles in continental habitats is crucial to designing effective management and conservation measures for this endangered species. A long-term data series (1993-2008) of European eel and European catfish (Silurus glanis) abundance in a freshwater canal of the Camargue water system (southern France), along with parallel data on water salinity and glass eel abundance in the adjacent VaccarSs lagoon, was analysed to identify the possible causes of decline in eel abundance observed in the canal during the last two decades. A model including glass eel recruitment and catfish abundance as covariates explained 78% of the observed variation in eel settlement success. Results suggest that (1) salinity does not play a significant role in determining the fraction of eels moving from the brackish lagoon to the canal; (2) density dependence affects settlement success, possibly through a reduction of juvenile survival in the adjacent lagoon; and (3) catfish abundance is negatively correlated with eel settlement. We discuss this latter point in terms of possible predation of catfish upon eels and/or inter-specific competition between the two species.

Tyrrhenian basins of Ligury as a new peri-Mediterranean ichthyogeographic district? Population structure of Telestes muticellus (Osteichthyes, Cyprinidae), a primary freshwater fish

Fri, 8 Jun 2018 14:50:39

The phylogeographic structure of vairone (Telestes muticellus), a primary freshwater fish endangered in a large part of its distributional range, was assessed: (i) to reconstruct the complex dispersion pattern in the upper Tyrrhenian hydrographic basins of Ligury, actually not recognised as peri- Mediterranean ichthyogeographic district, and (ii) to evidence the shape of population genetic structure as useful tool for future conservation strategies. A partial fragment of mitochondrial DNA cytochrome b (497 bp) was sequenced in 109 specimens sampled from eight populations, along an east-west geographic gradient. Fourteen haplotypes were identified, confirming the evolutionary distance between the two co-generic species: T. muticellus as 'Ligurian' clade and T. souffia as 'French' clade. The Nested Clade Analysis (NCA), the population genetic variability and population structure suggested a natural colonization occurred throughout the crossing of Alpine and Apennine watershed. The hierarchical Analysis of Molecular Variance (AMOVA) confirmed a geographic distinction between the populations from western (WTL) and from eastern (ETL) Tyrrhenian basins of Ligury colonised through the river capture processes along the Maritime Alpine watershed (Padano-Venetian district) and along the Apennine watershed (Tuscano-Latium district), respectively. Our results, evidencing the lack of genetic contiguity among vairone populations of the upper Tyrrhenian hydrographic basins of Ligury, allowed to recognise the presence of two management units (MUs) for its conservation.

The ecology of European ponds: defining the characteristics of a neglected freshwater habitat

Fri, 8 Jun 2018 14:48:52

There is growing awareness in Europe of the importance of ponds, and increasing understanding of the contribution they make to aquatic biodiversity and catchment functions. Collectively, they support considerably more species, and specifically more scarce species, than other freshwater waterbody types. Ponds create links (or stepping stones) between existing aquatic habitats, but also provide ecosystem services such as nutrient interception, hydrological regulation, etc. In addition, ponds are powerful model systems for studies in ecology, evolutionary biology and conservation biology, and can be used as sentinel systems in the monitoring of global change. Ponds have begun to receive greater protection, particularly in the Mediterranean regions of Europe, as a result of the identification of Mediterranean temporary ponds as a priority in the EU Habitats Directive. Despite this, they remain excluded from the provisions of the Water Framework Directive, even though this is intended to ensure the good status of all waters. There is now a need to strengthen, develop and coordinate existing initiatives, and to build a common framework in order to establish a sound scientific and practical basis for pond conservation in Europe. The articles presented in this issue are intended to explore scientific problems to be solved in order to increase the understanding and the protection of ponds, to highlight those aspects of pond ecology that are relevant to freshwater science, and to bring out research areas which are likely to prove fruitful for further investigation.

Trace metals in marine, brackish and freshwater prawns (Crustacea, Decapoda) from northeast Algeria

Fri, 8 Jun 2018 14:48:17

The concentrations of the trace metals Zn, Cu, Fe, Cd and Pb were measured in four caridean decapods; Atyaephyra desmaresti, Palaemonetes varians, Parapenaeus longirostris and Aristeus antennatus, from freshwater , estuarine and marine habitats in northeast Algeria variably affected by anthropogenic metal contamination. The two coastal species (P. longirostris and A. antennatus) are a food source for the local population. Accumulated metal concentrations varied interspecifically, and intraspecifically between sites and between seasons, except in the case of Aristeus antennatus. The fresh and brackish water species (Atyaephyra desmaresti and Palaemonetes varians) accumulated more Cd and Pb than their marine counterparts. Results are discussed with respect to anthropogenic inputs and the environmental conditions of the regions studied.

A predictive model for freshwater bioassessment (Mondego River, Portugal)

Fri, 8 Jun 2018 14:47:09

We sampled macroinvertebrates at 75 locations in the Mondego river catchment, Central Portugal, and developed a predictive model for water quality assessment of this basin, based on the Reference Condition Approach. Sampling was done from June to September 2001. Fifty-five sites were identified as "Reference sites" and 20 sites were used as "Test sites" to test the model. At each site we also measured 40 habitat variables to characterize water physics and chemistry, habitat type, land use, stream hydrology and geographic location. Macroinvertebrates were generally identified to species or genus level; a total of 207 taxa were found. By Unweighted Pair Group Method with Arithmetic mean (UPGMA) clustering and analysis of species contribution to similarities percentage (SIMPER), two groups of reference sites were established. Using Discriminant Analysis (stepwise forward), four variables correctly predicted 78% of the reference sites to the appropriate group: stream order, pool quality, substrate quality and current velocity. Test sites' environmental quality was established from their relative distance to reference sites, in MDS ordination space, using a series of bands (BEAST methodology). The model performed well at upstream sites, but at downstream sites it was compromised by the lack of reference sites. As with the English RIVPACS predictive model, the Mondego model should be continually improved with the addition of new reference sites. The adaptation of the Mondego model methodology to the Water Framework Directive is possible and would consist mainly of the integration of the WFD typology and increasing the number of ellipses that define quality bands.

Changes in functional biodiversity in an invaded freshwater ecosystem: the Moselle River

Fri, 8 Jun 2018 14:43:03

The spread of non-indigenous species and the decline of autochthonous ones are leading to a homogenization of freshwater fauna in terms of systematic units, but the functional consequences are poorly documented. We studied the peculiar case of the lower, French section of the Moselle River where 20 invertebrate species have been introduced since 1854, with a rate increasing exponentially with time. Dredge sampling performed in 1994, 1996, 2000 and 2001 at four sampling stations allowed for an evaluation of faunal changes in terms of composition, structure and function. During this period, no structural changes were recorded in spite of multiple, new and successful introductions. The evaluation of functional modifications was based on a typology of taxa exhibiting homogeneous biological/ecological traits. Functional diversity, measured as the diversity of taxa distribution among functional groupings, revealed a significant increase between 1994/1996 and 2000/2001 because those species that were over-represented during the former period reached more equilibrated densities during the latter. The major, indirect implications of these functional. changes are discussed.

Global diversity of dobsonflies, fishflies, and alderflies (Megaloptera : Insecta) and spongillaflies, nevrorthids, and osmylids (Neuroptera : Insecta) in freshwater

Fri, 8 Jun 2018 12:21:35

The insect orders Megaloptera and Neuroptera are closely related members of the superorder Neuropterida, a relict lineage of holometabolous insects that also includes the Raphidoptera. Megaloptera, composed of the families Sialidae and Corydalidae (including subfamilies Chauliodinae and Corydalinae), has fully aquatic larvae that occur in a wide variety of lotic and lentic habitats, including temporary streams. In total, 2 of 17 families of Neuroptera have aquatic larvae: Nevrorthidae live in the benthos of fast-flowing streams and Sisyridae reside on freshwater sponges. A third family of Neuroptera, Osmylidae, contains some water-dependent species that reside under leaves and rocks along the margins of waterbodies. We recognize 328 extant, described species of Megaloptera (composed of 116 species of Chauliodinae, 131 species of Corydalinae, and 81 species of Sialidae) and 73 species of aquatic Neuroptera (composed of 12 species of Nevrorthidae and 61 species of Sisyridae). Additionally, we estimate that 45 species of Osmylidae are water-dependent, although the ecology of this group is poorly understood. Chauliodinae and Corydalidae are both found in the New World, the Oriental region, and South Africa, but are absent from Europe, the Middle East, Central Asia, tropical Africa, and boreal regions. Chauliodinae is quite speciose in Australia, whereas Corydalinae is absent. Sialidae is most speciose in temperate regions, and is absent from tropical Africa and portions of the Oriental region. Sisyridae and Osmylidae are nearly cosmopolitan, but the relict family Nevrorthidae is limited to Japan, the Mediterranean, and Australia. The discovery of many new species in recent years, particularly among Corydalidae in the Neotropics and China, suggests that our knowledge of aquatic neuropterid diversity is far from complete.

Concurrent evolution of ancient sister lakes and sister species: the freshwater gastropod genus Radix in lakes Ohrid and Prespa

Fri, 8 Jun 2018 12:19:30

Ancient sister lakes are considered to be ancient lakes lying in close geographic proximity, sharing a related origin and significant time of co-existence, usually having hydrological connection as well as a balanced degree of faunal overlap and distinctness. A paradigm for studying sister lake relationships are the ancient lakes Ohrid and Prespa in the Balkans, which are characterized by high degrees of endemicity. Three general patterns of endemic species can be distinguished for these lakes: (1) taxa that are endemic to either lake, with no close relatives in the respective sister lake, (2) closely related but distinct endemic taxa in both lakes (sister species) and (3) shared endemic taxa occurring in both lakes. In the present paper, two endemic freshwater pulmonate gastropod species, Radix relicta (Lake Ohrid) and R. pinteri (Lake Prespa), are used to study the evolution of presumed sister species based on biogeographical and comparative DNA data from world-wide Radix taxa. Phylogenetic, phylogeographical and parametric bootstrap analyses all suggest a sister group relationship of R. relicta and R. pinteri (pattern 2 of endemic diversity). Sister to these two taxa is the widespread R. ampla, which does not occur in the vicinity of lakes Ohrid and Prespa. The southern feeder spring complexes of Lake Ohrid are inhabited by another lineage (Radix sp. 1), which resembles Radix relicta in morphology/anatomy. For Lake Prespa, the widespread R. auricularia was reported in addition to the endemic R. pinteri. Comparative phylogenetic data favour a western Adriatic zoogeographical affinity of lakes Ohrid and Prespa over an Aegean-Anatolian faunal connection. The status of lakes Ohrid and Prespa as sister lakes is evaluated in the light of current knowledge on gastropod speciation and endemism in these hotspots of biodiversity.

Biota contamination by PCBs and trace metals in the freshwater estuary of the River Seine (France)

Fri, 8 Jun 2018 12:16:56

We studied the impact of urban and industrial activity upon the occurrence and the distribution of pollutants in the fresh estuary of the River Seine. Contamination was investigated under dry weather conditions, by determination of PCB and trace metal levels upstream and downstream of Rouen and the pollutant content of organisms with different positions in the trophic web. PCB contents of roach were higher downstream than upstream of Rouen. Cd levels showed a regular four fold increase from upstream to downstream of Rouen. Cyprinidae (ablet, roach) showed similar PCB or even higher trace metal levels than their predators (Percidae). This result suggests that contaminated food intake was not the main pathway for pollutant accumulation.

Freshwater goby life history in a Mediterranean stream

Fri, 8 Jun 2018 12:15:42

The Italian goby Gobius nigricans is a running-water-dwelling species inhabiting the Tuscano-Latium district and threatened by several human activities. Many aspects of its biology are currently unknown, such as the dynamic potentialities. Since age determination and dynamic assessment are considered an important tool for a correct management strategy, we aimed to investigate some aspects of the Italian goby life history by applying the fish stock assessment principles, collecting data on fertility, population structure (age-class number), growth (i.e., curvature parameter and asymptotic length), mortality (natural and due to the fishing), and longevity of a central Italian goby population to know the status and dynamic properties of the Italian goby in Mediterranean river systems and to provide a baseline for comparison with other populations. Females are subject to a strong selective pressure to quickly reach a small size to optimize reproductive output, while acquisition of a large size favored males for a more easy access to breeder females (the asymptotic length was higher in males than in females). Moreover, appreciable between-sex differences were found in both growth pattern (the growth rate was lower in females than in males) and dynamic potentialities. In particular, the mortality rate was lower in females, whereas the longevity was slightly lower in males, although the two sexes showed similar values for the two latter properties. There is considerable scope for further work on the G. nigricans growth and other freshwater gobies because information on population and dynamic properties, and assessment of factors affecting growth are still very insufficient.

Fungal parasitism in freshwater calanoid population: ecological consequences and possible mechanisms involved in the infection process

Fri, 8 Jun 2018 12:15:07

This paper reports the results of a study on a zoosporic fungus (Saprolegniaceae) parasitizing populations of Eudiaptomus intermedius (Copepoda, Calanoida) in mountain lakes located in the Northern Apennines, Italy. The dynamics of this infectious process was previously described in one of the lakes of the study area. The virulence is particularly high at the end of the calanoid reproductive phase, when the fungal hyphae penetrate the host eggs provoking their degeneration. Here new data are presented and the phenology of the host-parasite interaction is comparatively analyzed in different years and in different sites. The occurrence of the parasite was assessed at a regional scale. Possible mechanisms involved in the pathogen dispersal and in the host recognition are proposed, and the ecological impact of the fungal parasitism on the calanoid populations is discussed.

Distribution patterns of freshwater molluscs along environmental gradients in the southern Guadiana River basin (SW Iberian Peninsula)

Fri, 8 Jun 2018 12:13:58

The taxonomic status of the freshwater mollusc fauna of the Iberian Peninsula it is reasonably well known, but, unlike other benthic macroinvertebrate, its distribution and ecology has been poorly studied. In this article, I study the relationships between environmental characteristics and distribution and community structure of freshwater molluscs along climatic, hydrological, physicochemical, and heterogeneity gradients in the southwestern Iberian Peninsula. Ninety-four sampling points were analysed, in which, in addition to habitat features, the presence/absence and abundance of species were evaluated. The environmental gradients were measured by use of principal-components analysis (PAC), which orders the variables along two gradients: headwaters-mouth gradient (PC1) and water availability (PC2). According to canonical correspondence analysis (CCA), the main environmental factors related to species distribution and community structure were conductivity, permanency, channel width, turbidity, slope, and distance to the main river axis. The relationship between biodiversity (measured as species richness and the Shannon-Weiner diversity index), the ratio of the number of introduced species to the total number of species (zoogeographic integrity coefficient), and environmental variables was best explained by a regression model incorporating, basically, the permanence of water in streams as the variable that accounted for most of the variance. This study demonstrates that the distribution of freshwater molluscs along a Mediterranean gradient highly stressed by drought depends, mainly, on the hydrological stability and environmental conditions of the headwaters and estuarine sites.

Biodiversity and distribution patterns of freshwater invertebrates in farm ponds of a south-western French agricultural landscape

Fri, 8 Jun 2018 12:10:07

We assessed the importance for biodiversity of man-made farm ponds in an agricultural landscape in SW France lacking natural wetlands. The ponds were originally created to provide a variety of societal services (irrigation, visual amenity, water for cattle, etc.). We also assessed the environmental factors influencing invertebrate assemblages in these ponds. Only 18 invertebrate taxa out of 114 taxa occurring in the study area were common to ponds and rivers indicating that the contribution of farm ponds to freshwater biodiversity was potentially high. A Self-Organizing Map (SOM, neural network) was used to classify 36 farm ponds in terms of the 52 invertebrate families and genera they supported, and to specify the influence of environmental variables related to land-use and to pond characteristics on the assemblage patterns. The SOM trained with taxa occurrences showed five clusters of ponds, most taxa occurring only in 1-2 clusters of ponds. Abandoned ponds tended to support higher numbers of taxa, probably because they were allowed to undergo a natural succession. Nevertheless, abandoned ponds were also amongst the largest, so that it remained difficult to separate the effects of pond size and abandonment, although both factors were likely to interact to favour higher taxon richness. The invertebrate communities in the ponds appeared to be influenced mainly by widely acting environmental factors (e.g. area, regionalization of assemblages) with little evidence that pond use (e.g. cattle watering, amenity) generally influenced assemblage composition. Our results support the idea that agricultural landscapes containing man-made ponds make a significant contribution to freshwater biodiversity indicating that protection of farm ponds from threats such as in-filling and pollution can make a positive contribution to the maintenance of aquatic biodiversity. This added value for biodiversity should be considered when calculating the economic costs and benefits of constructing water bodies for human activities.

Colonization of freshwater habitats by an introduced crayfish, Procambarus clarkii, in Southwest Iberian Peninsula

Fri, 8 Jun 2018 12:09:58

The introduction of some crustacean species has produced alterations of freshwater environments and declines of native species worldwide. The red swamp crayfish, Procambarus clarkii Girard, was introduced in the Southwest Iberian Peninsula in the 1970's, producing severe impacts on rice agriculture and on native biota such as macrophytes, gastropods, native crayfish and amphibians. We studied the distribution of P. clarkii in two areas of SW Iberian Peninsula: the Sado River basin (SW Portugal), an area colonized by this species around 1990, and the Parque Natural del Entorno de Donana (SW Spain), colonized soon after its introduction in the Iberian Peninsula, in the 1970's. Our main goal was to determine which factors limit crayfish distribution, which could help to identify the most effective management practices to contain its spread. Procambarus clarkii was found in most types of water bodies, including small and shallow ones. Distance to a crayfish source was the single predictor variable explaining crayfish occurrence in most types of habitats and in both areas. The only exception was for the Sado permanent stream points, where crayfish presence was negatively affected by an interaction between elevation and flow velocity. Other habitat characteristics have apparently little or no importance for its successful colonization. Moreover, this study indicated that overland dispersal is apparently a frequent phenomenon in this species. Our findings can be used to determine which habitats are most likely to be colonized by the crayfish and to develop practical measures which may limit its spread and minimize its impacts.

Atlantic Island freshwater ecosystems: challenges and considerations following the EU Water Framework Directive

Fri, 8 Jun 2018 12:07:13

The Water Framework Directive or WFD constitutes a major step forward in the protection of the aquatic environment and associated habitats, since it legislates for the characterization of surface water bodies across defined ecoregions and the development of ecological monitoring systems based upon elements of the aquatic biota. The Macaronesian archipelagos include the Azores, Madeira and the Canary Islands. The peripheral situation of the Macaronesian islands has set them apart from many European initiatives concerning the implementation of the WFD, which is biased towards better known continental systems. As a result, they have been included in the same ecoregion as the Iberian Peninsula and the Balearic Islands for management purposes. However, because of their oceanic situation and volcanic origin, the freshwater systems of the Macaronesian islands differ strongly from continental systems in watershed morphology and the composition of the biotic assemblages, which merits separate identification rather than inclusion within the larger Iberic-Macaronesian ecoregion and special attention concerning regional implementation of programmes of measures under the Directive.

Global diversity of cumaceans & tanaidaceans (Crustacea : Cumacea & Tanaidacea) in freshwater

Fri, 8 Jun 2018 12:02:11

Cumacea and Tanaidacea are marginal groups in continental waters. Although many euryhaline species from both groups are found in estuaries and coastal lagoons, most occur only temporarily in non-marine habitats, appearing unable to form stable populations there. A total of 21 genuinely non-marine cumaceans are known, mostly concentrated in the Ponto-Caspian region, and only four tanaids have been reported from non-marine environments. Most non-marine cumaceans (19 species) belong in the Pseudocumatidae and appear restricted to the Caspian Sea (with salinity up to 13 parts per thousand) and its peripheral fluvial basins, including the northern, lower salinity zones of the Black Sea (Sea of Azov). There are nine Ponto-Caspian genera, all endemic to the region. Only two other taxa (in the family Nannastacidae) occur in areas free of any marine-water influence, in river basins in North and South America. Both seem able to survive in waters of raised salinity of the lower reaches of these fluvial systems; but neither has been recorded in full salinity marine environments. The only non-marine tanaidacean thus far known lives in a slightly brackish inland spring in Northern Australia. The genus includes a second species, from a brackish-water lake at the Bismarck Archipelago, tentatively included here as non-marine also. Two additional species of tanaidaceans have been reported from non-marine habitats but both also occur in the sea.

Les cours d'eau temporaires du massif des Maures : hydrologie, hydrochimie, communautés algales et animales

Thu, 7 Jun 2018 09:45:41

Importance de la dérive dans la mise en place des communautés d'invertébrés dans les cours d'eau temporaires de la Provence calcaire

Thu, 7 Jun 2018 09:44:35

Effects of changing climate on European stream invertebrate communities: A long-term data analysis

Tue, 27 Mar 2018 11:13:55

Long-term observations on riverine benthic invertebrate communities enable assessments of the potential impacts of global change on stream ecosystems. Besides increasing average temperatures, many studies predict greater temperature extremes and intense precipitation events as a consequence of climate change. In this study we examined long-term observation data (10–32years) of 26 streams and rivers from four ecoregions in the European Long-Term Ecological Research (LTER) network, to investigate invertebrate community responses to changing climatic conditions. We used functional trait and multi-taxonomic analyses and combined examinations of general long-term changes in communities with detailed analyses of the impact of different climatic drivers (i.e., various temperature and precipitation variables) by focusing on the response of communities to climatic conditions of the previous year. Taxa and ecoregions differed substantially in their response to climate change conditions. We did not observe any trend of changes in total taxonomic richness or overall abundance over time or with increasing temperatures, which reflects a compensatory turnover in the composition of communities; sensitive Plecoptera decreased in response to warmer years and Ephemeroptera increased in northern regions. Invasive species increased with an increasing number of extreme days which also caused an apparent upstream community movement. The observed changes in functional feeding group diversity indicate that climate change may be associated with changes in trophic interactions within aquatic food webs. These findings highlight the vulnerability of riverine ecosystems to climate change and emphasize the need to further explore the interactive effects of climate change variables with other local stressors to develop appropriate conservation measures.

Recruitment of the Crabs Eurypanopeus depressus, Rhithropanopeus harrisii, and Petrolisthes armatus to Oyster Reefs: the Influence of Freshwater Inflow

Thu, 15 Mar 2018 14:21:10

Oyster reefs provide structural habitat for resident crabs and fishes, most of which have planktonic larvae that are dependent upon transport/retention processes for successful settlement. High rates of freshwater inflow have the potential to disrupt these processes, creating spatial gaps between larval distribution and settlement habitat. To investigate whether inflow can impact subsequent recruitment to oyster reefs, densities of crab larvae and post-settlement juveniles and adults were compared in Estero Bay, Florida, over 22 months (2005-2006). Three species were selected for comparison: Petrolisthes armatus, Eurypanopeus depressus, and Rhithropanopeus harrisii. All are important members of oyster reef communities in Southwest Florida; all exhibit protracted spawning, with larvae present throughout the year; and each is distributed unevenly on reefs in different salinity regimes. Recruitment to oyster reefs was positively correlated with bay-wide larval supply at all five reefs examined. Species-specific larval connectivity to settlement sites was altered by inflow: where connectivity was enhanced by increased inflow, stock-recruitment curves were linear; where connectivity was reduced by high inflows, stock-recruitment curves were asymptotic at higher larval densities. Maximum recruit density varied by an order of magnitude among reefs. Although live oyster density was a good indicator of habitat quality in regard to crab density, it did not account for the high variability in recruit densities. Variation in recruit density at higher levels of larval supply may primarily be caused by inflow-induced variation in larval connectivity, creating an abiotic simulation of what has widely been regarded as density dependence in stock-recruitment curves.

Magnitude and Patterns of Change in Submerged Aquatic Vegetation of the Tidal Freshwater Hudson River

Thu, 15 Mar 2018 14:20:27

Three aerial photography inventories were used to examine change in submerged aquatic vegetation (SAV) in the tidal freshwater Hudson River over the interval 1997 to 2007. Overall, there was about a 30 % net decline in SAV coverage although there were also many individual areas of expansion. The invasive water chestnut (Trapa natans) did not change appreciably in net cover over the interval, and there was replacement of SAV by water chestnut along with slightly fewer cases of SAV replacing the exotic. A fine-scale (100 m by 100 m quadrats) analysis showed that about 30 % of quadrats that supported vegetation changed by more than 10 % in plant cover and overall SAV was quite dynamic. SAV in the Hudson is limited by light which is in turn controlled by suspended sediment. SAV was rarely found at depths > 1 m below low water, and interannual differences in clarity affected the ability of SAV beds to maintain locally supersaturated levels of dissolved oxygen. We found that location within the River channel (proximity to shore) influenced the magnitude and variability in change in SAV between census periods. The physical nature of the adjacent shoreline also affected the magnitude of change with greater declines in cover in areas next to hard-engineered shore types. SAV in the Hudson is highly dynamic, apparently quite resilient, and the control of light by suspended sediment rather than phytoplankton growth offers a contrast to eutrophication-influenced changes in other estuaries. Management and protection of SAV habitat must recognize the highly variable nature of plant cover and that absence in any particular year does not preclude future appearance of submerged plants at that location.

Comments on Buzan et al. "Positive Relationships between Freshwater Inflow and Oyster Abundance in Galveston Bay, Texas"

Thu, 15 Mar 2018 14:19:56

Buzan et al. critique Turner's (Estuaries and Coasts 29:345-352, 2006) analysis of the relationship between freshwater inflow and oyster productivity in the Gulf of Mexico, using 16 years of fisheries-independent data for Galveston Bay. They conclude that the catch-per-unit effort (CPUE; number h(-1)) of marketable oysters increase 1 to 2 years after years with increased freshwater inflows, and they express concerns that water supply managers may mis-apply the results of Turner (Estuaries and Coasts 29:345-352, 2006) to justify a reduced freshwater inflow to Galveston Bay. I find no relationship between the CPUE of oyster spat or marketable oyster density and the commercial harvest, but do find a strong inverse relationship between harvest and river discharge in Galveston Bay. There are three possible factors that may explain why the annual variations in the fisheries-independent data are not coherent with the annual variations in commercial harvest: variable levels of water quality, inconsistent fishing effort, and the fact that the fisheries-independent data are not prorated for the area of the reefs actually fished. I concur, completely, with the apprehension that reductions in freshwater inflow will be implemented without examining the full set of assumptions and consequences, and thereby compromise estuarine ecosystem quality, and perhaps permanently, before mistakes can be seen or reversed.

Defining Optimal Freshwater Flow for Oyster Production: Effects of Freshet Rate and Magnitude of Change and Duration on Eastern Oysters and Perkinsus marinus Infection

Thu, 15 Mar 2018 14:19:05

In coastal Louisiana, the development of large-scale freshwater diversion projects has led to controversy over their effects on oyster resources. Using controlled laboratory experiments in combination with a field study, we examined the effects of pulsed freshwater events (freshet) of different magnitude, duration, and rate of change on oyster resources. Laboratory and field evidence indicate that low salinity events (< 5 psu) decreased Perkinsus marinus infection intensities. Furthermore, when salinity was low (< 5 psu), parasite infection intensities continued to decrease even as temperatures exceeded 20A degrees C. At the same time, oyster growth was positively correlated with salinity. To maximize oyster production, data indicate that both low and high salinity events will be necessary.

Suspended sediment transport in the freshwater reach of the Hudson River estuary in eastern New York

Thu, 15 Mar 2018 14:19:02

Estuarine Habitat and Demographic Factors Affect Juvenile Chinook (Oncorhynchus tshawytscha) Growth Variability in a Large Freshwater Tidal Estuary

Thu, 15 Mar 2018 14:18:56

Estuarine rearing has been shown to enhance within watershed biocomplexity and support growth and survival for juvenile salmon (Oncorhynchus sp.). However, less is known about how growth varies across different types of wetland habitats and what explains this variability in growth. We focused on the estuarine habitat use of Columbia River Chinook salmon (Oncorhynchus tshawytscha), which are listed under the Endangered Species Act. We employed a generalized linear model (GLM) to test three hypotheses: (1) juvenile Chinook growth was best explained by temporal factors, (2) habitat, or (3) demographic characteristics, such as stock of origin. This study examined estuarine growth rate, incorporating otolith microstructure, individual assignment to stock of origin, GIS habitat mapping, and diet composition along similar to 130 km of the upper Columbia River estuary. Juvenile Chinook grew on average 0.23 mm/day in the freshwater tidal estuary. When compared to other studies in the basin our growth estimates from the freshwater tidal estuary were similar to estimates in the brackish estuary, but similar to 4 times slower than those in the plume and upstream reservoirs. However, previous survival studies elucidated a possible tradeoff between growth and survival in the Columbia River basin. Our GLM analysis found that variation in growth was best explained by habitat and an interaction between fork length and month of capture. Juvenile Chinook salmon captured in backwater channel habitats and later in the summer (mid-summer and late summer/fall subyearlings) grew faster than salmon from other habitats and time periods. These findings present a unique example of the complexity of understanding the influences of the many processes that generate variation in growth rate for juvenile anadromous fish inhabiting estuaries.

Preliminary Examination of How Human-driven Freshwater Flow Alteration Affects Trophic Ecology of Juvenile Snook (Centropomus undecimalis) in Estuarine Creeks

Thu, 15 Mar 2018 14:18:08

Maintaining proper freshwater and marine inputs is essential for estuarine function. Alteration of freshwater flows into small tributaries that traverse the upland-estuarine margin may be especially problematic, e.g., by impacting the nursery areas for juvenile finfish and shellfish. We used stomach contents and stable isotope analysis (delta(13)C, delta(15)N) to examine effects of freshwater flow alterations on the trophic ecology of juvenile common snook (Centropomus undecimalis) in four mangrove creeks with different freshwater flow regimes. Diet diversity in less degraded creeks was greater than in more degraded creeks, and the importance (by % mass) of the top three preys was disproportionately higher in the more degraded creeks. Stable isotope measures of trophic diversity corroborate these trends, suggesting higher intraspecific trophic diversity in less degraded creeks. The difference in diet diversity of juvenile snook may be an indicator of an overall change in ecosystem function and these shifts in food web structure may affect the rate that juveniles of this and other species with similar habitat requirements successfully join the adult population.

Loading, Transformation, and Retention of Nitrogen and Phosphorus in the Tidal Freshwater James River (Virginia)

Thu, 15 Mar 2018 14:17:33

A nutrient mass balance for the tidal freshwater segment of the James River was used to assess sources of nutrients supporting phytoplankton production and the importance of the tidal freshwater zone in mitigating nutrient transport to marine waters. Monthly mass balances for 2007-2010 were based on riverine inputs, local point sources (including sewer overflow events), ungauged inputs, riverine outputs, and tidal exchange. The tidal freshwater James River received exceptionally high areal loads (446 mg TN m(-2) day(-1) and 55 mg TP m(-2) day(-1)) compared to other estuaries in the region and elsewhere. P inputs were principally from riverine sources (84 %) whereas point sources contributed appreciably (54 %) to high N loads. Despite high loading rates and short water residence time, areal mass retention was high (143 mg TN m(-2) day(-1) and 33 mg TP m(-2) day(-1)). Retention of particulate fractions occurred during high discharge, whereas dissolved inorganic fractions were retained during low discharge when chlorophyll-a concentrations were high. On an annualized basis, P was retained more effectively (59 %) than N (32 %). P was retained by abiotic mechanisms via trapping of particulate forms, whereas N was retained through biological assimilation of dissolved inorganic forms. Results from a limited suite of stable isotope determinations suggest that DIN from point sources was preferentially retained. Combined inputs from diffuse and point sources accounted for only 20 % and 36 % (respectively) of estimated algal N and P demand, indicating that internal nutrient recycling was important to sustaining high rates of phytoplankton production in the tidal freshwater zone.

Temporal and spatial variability of freshwater plumes in a semienclosed estuarine-bay system

Thu, 15 Mar 2018 14:17:00

Changes in plankton community structure and function in response to variable freshwater flow in two tributaries of the Chesapeake Bay

Thu, 15 Mar 2018 14:16:57

The influence of phytoplankton community composition on primary productivity along the riverine to freshwater tidal continuum in the San Joaquin River, California

Thu, 15 Mar 2018 14:16:56

Low-pH Freshwater Discharges Drive Spatial and Temporal Variations in Life History Traits of Neritic Copepod Acartia tonsa

Thu, 15 Mar 2018 14:16:29

Land weathering by river runoff makes coastal oceans highly variable ecosystems in terms of seawater pH; however, its effects on biological components and, hence, on the coastal ecosystem functioning has been scarcely addressed. In this study, we determined part of the spatial and seasonal variability of the physical-chemical characteristics of seawater, and life history traits of the neritic copepod Acartia tonsa, along an estuarine-to-coastal zone geographic gradient in the southern Pacific Ocean. There, freshwater influences give rise to sharp gradients in pH, salinity, and temperature, which in turn, may affect the fitness of copepod populations inhabiting along the gradient. In fact, most of the studied copepod traits (egg size, ingestion, and egg production rates) were moderately (r (2) = 0.5, p < 0.05) to robustly (r (2) = 0.9, p < 0.05) explained by physical-chemical and biological (food abundance and composition) factors. Noteworthy was the negative relationship between low-pH waters and copepod reproductive outcomes. This effect was far evident in the estuarine area where small brood sizes and depleted egg production rates were significantly correlated with low seawater pH (r (2) = 0.6, p < 0.05). If short-term episodes of low-pH seawater constitute a significant threshold for reproduction, current findings should stimulate a better description of pH variability in coastal zones, as well as the study of biological consequences derived from the interaction between pH and others drivers on coastal marine populations.

Anaerobic Metabolism in Tidal Freshwater Wetlands: III. Temperature Regulation of Iron Cycling

Thu, 15 Mar 2018 14:16:27

Understanding the ecological processes that regulate the production and fate of methane (CH4) in wetland soils is essential for forecasting wetland CH4 emissions. Iron reduction is an important carbon mineralization pathway that is capable of suppressing CH4 production in freshwater wetlands, but our understanding of temperature regulation of iron oxide respiration and the subsequent impacts on CH4 production is limited. We tested the hypothesis that temperature regulates iron reduction rates indirectly through differential effects on Fe(II) oxidation versus Fe(III) reduction, which ultimately determines the size of the microbially labile, poorly crystalline Fe(III) pool. Our study indicates that rates of iron reduction are more sensitive to changes in temperature than rates of iron oxidation, which creates imbalance in the relative proportion of Fe(II) and Fe(III) in the poorly crystalline soil iron pool as temperatures change. Our results suggest that warmer temperatures can cause the Fe(III) oxide pool to decline, limiting the Fe(III) supply to iron reducers and relieving competition for organic carbon with methanogens.

Hydrologic Versus Biogeochemical Controls of Denitrification in Tidal Freshwater Wetlands

Thu, 15 Mar 2018 14:15:10

Tidal freshwater wetlands (TFW) alter nitrogen concentrations in river water, but the role of these processes on a river's downstream nitrogen delivery is poorly understood. We examined spatial and temporal patterns in denitrification in TFW of four rivers in North Carolina, USA and evaluated the relative importance of denitrification rate and inundation on ecosystem-scale N-2 efflux. An empirical model of TFW denitrification was developed to predict N-2 efflux using a digital topographic model of the TFW, a time series of water level measurements, and a range of denitrification rates. Additionally, a magnitude-frequency analysis was performed to investigate the relative importance of storm events on decadal patterns in N-2 efflux. Spatially, inundation patterns exerted more influence on N-2 efflux than did the range of denitrification rate used. Temporal variability in N-2 efflux was greatest in the lower half of the tidal rivers (near the saline estuary) where inundation dynamics exerted more influence on N-2 efflux than denitrification rate. N-2 efflux was highest in the upper half of the rivers following storm runoff, and under these conditions variation in denitrification rate had a larger effect on N-2 efflux than variability in inundation. The frequency-magnitude analysis predicted that most N-2 efflux occurred during low flow periods when tidal dynamics, not storm events, affected TFW inundation. Tidal hydrology and riparian topography are as important as denitrification rate in calculating nitrogen loss in TFW; we present a simple empirical model that links nitrogen transport in rivers with loss due to denitrification in TFW.

Do Juvenile White Perch Morone americana Grow Better in Freshwater Habitats of the Blackwater River Drainage (Chesapeake Bay, MD, USA)?

Thu, 15 Mar 2018 14:15:06

Increasing rates of freshwater habitat loss in the Chesapeake Bay (and elsewhere) have renewed interest in the role of freshwater in population integrity for euryhaline fishes. Freshwater habitats may be important nurseries for juveniles of anadromous species. Using length-weight residuals and scales, we determined if body condition and growth of juvenile (< 120 mm total length) white perch Morone americana (a semi-anadromous species) differed between brackish and freshwater tributaries within the Blackwater River drainage (Chesapeake Bay Watershed, U.S.A.). We then examined how monthly variation in body condition varied with monthly variation in selected environmental factors. Body condition differed between tributaries and was greater in freshwater (specific conductivity < 0.45 mS) than brackish water when water temperature was greater than 9.6A degrees C. White perch growth rates did not differ between tributaries, except for a short time during summer or early fall. Some anadromous fishes may spawn in freshwater to promote greater body condition, thereby ensuring a quality contingent of individuals for the population. With continued loss or impairment of freshwater habitat, the availability of nurseries for juvenile white perch will be reduced and reduce the number of quality juveniles recruiting to the adult population.

Influences of Salinity and Light Availability on Abundance and Distribution of Tidal Freshwater and Oligohaline Submersed Aquatic Vegetation

Thu, 15 Mar 2018 14:15:00

Submersed aquatic vegetation (SAV) communities have undergone declines worldwide, exposing them to invasions from non-native species. Over the past decade, the invasive species Hydrilla verticillata has been documented in several tributaries of the lower Chesapeake Bay, Virginia. We used annual aerial mapping surveys from 1998 to 2007, integrated with spatial analyses of water quality data, to analyze the patterns and rates of change of a H. verticillata-dominated SAV community and relate them to varying salinity and light conditions. Periods of declining SAV coverage corresponded to periods where salinities exceeded 7 and early growing season (April to May) Secchi depths were < 0.4 m. Increases were driven by the expansion of H. verticillata along with several other species into the upper estuary, where some areas experienced an 80% increase in cover. Field investigations revealed H. verticillata dominance to be limited to the upper estuary where total suspended solid concentrations during the early growing season were < 15 mg l(-1) and salinity remained < 3. The effect of poor early growing season water clarity on annual SAV growth highlights the importance of water quality during this critical life stage. Periods of low clarity combined with periodic salinity intrusions may limit the dominance of H. verticillata in these types of estuarine systems. This study shows the importance of the use of these types of biologically relevant episodic events to supplement seasonal habitat requirements and also provides evidence for the potential important role of invasive species in SAV community recovery.

Otolith Microchemistry Reveals Substantial Use of Freshwater by Southern Flounder in the Northern Gulf of Mexico

Thu, 15 Mar 2018 14:14:52

Southern flounder Paralichthys lethostigma is a recreationally and commercially important species along the western Atlantic and northern Gulf of Mexico coasts that can exhibit complex early-life habitat-use patterns. Herein, we used an otolith microchemical approach to test the conventional wisdom that juvenile southern flounder spend most of their early life in low-salinity areas of estuaries, focusing on the largely unstudied population in the Mobile-Tensaw Delta, AL. Analysis of strontium/calcium concentrations in otolith cores of age 0 juveniles demonstrated that 68% of these individuals hatched in high-salinity waters before moving into freshwater habitats, with the remaining individuals being spawned in or near freshwater habitat. Further, otolith edge Sr/Ca concentrations revealed that even juveniles used freshwater habitats, particularly during freshwater/oligohaline conditions in our study system. Otolith edge Sr/Ca ratios for fish collected during high-salinity periods differed significantly among collection regions, suggesting seasonal differences in patterns of habitat use between individuals collected upstream (i.e., freshwater habitats) vs. downstream (i.e., euryhaline habitats). These data support the hypothesis that early-life stages of a substantial portion of a coastal southern flounder population use freshwater habitat.

Organic matter sources supporting lower food web production in the tidal freshwater portion of the York River estuary, Virginia

Thu, 15 Mar 2018 14:14:29

Net aboveground primary production and soil properties of floating and attached freshwater tidal marshes in the Rio de la Plata estuary, Argentina

Thu, 15 Mar 2018 14:14:25

Phytoplankton production and nutrient distributions in a subtropical estuary: Importance of freshwater flow

Thu, 15 Mar 2018 14:14:24

Tidal Freshwater Wetlands: Variation and Changes

Thu, 15 Mar 2018 14:13:39

Tidal freshwater wetlands (TFW) are situated in the upper estuary in a zone bordered upstream by the nontidal river and downstream by the oligohaline region. Here, discharge of freshwater from the river and the daily tidal pulse from the sea combine to create conditions where TFW develop. TFW are often located where human population density is high, which has led to wetland degradation or destruction. Globally, TFW are largely restricted to the temperate zone where the magnitude of annual river discharge prevents saline waters from penetrating too far inland. The constant input of river water delivers high loads of sediments, dissolved nutrients, and other suspended matter leading to high sedimentation rates and high nutrient levels. Prominent biogeochemical processes include the transformation of nitrogen by bacteria and immobilization of phosphate. A diverse, characteristic vegetation community develops which supports a rich fauna. Biotic diversity is highest in the high marsh areas and decreases in the lower levels where tidal inundation is greatest. Benthic fauna is rather poor in diversity but high in biomass compared to other regions of the estuary. Global climate change is a threat for this system directly by sea level rise, which will cause brackish water to intrude into the fresh system, and indirectly during droughts, which reduce river discharge. Salinity will affect the presence of flora and fauna and facilitates sulfate reduction of organic matter in the soil. Increased decomposition of organic matter following saltwater intrusion can result in a lowering of wetland surface elevation. The papers assembled in this issue focus on how these tidal freshwater wetlands have changed over recent time and how they may respond to new impacts in the future.

Vegetation Dynamics in a Tidal Freshwater Wetland: A Long-Term Study at Differing Scales

Thu, 15 Mar 2018 14:13:37

Tidal freshwater wetlands are complex, species-rich ecosystems located at the interface between tidal estuaries and nontidal rivers. This study conducted on the Patuxent River estuary in Maryland was designed to assess vegetation dynamics over several decades to determine if there were directional changes in the dominant communities. Aerial photographs (1970, 1989, and 2007) documented broad-scale spatial changes in major plant communities. The coverage of areas dominated by Nuphar lutea and Phragmites australis expanded; mixed vegetation and scrub-shrub habitats were essentially unchanged; and Typha and Zizania aquatica communities fluctuated in coverage. Data collected between 1988 and 2010 from permanent plots and transects were used to examine fine-scale changes. Shifts in the importance of some species through time were observed, but there were no directional changes in community species composition. The lack of directional change as measured at a fine scale is characteristic of tidal freshwater wetlands in which variations in the abundance of individual species, especially annuals, are responsible for most short-term change in species composition. Changes in the composition of plant communities are interpreted as responses to variations in vertical accretion, stability of habitat types, invasive plant species, and herbivores. In the future, vegetation changes are likely to occur as a result of the intrusion of brackish water and increased flooding associated with global climate change and sea level rise. This long-term study establishes a baseline from which potential future changes to tidal freshwater wetlands can be better understood.

Juvenile Spotted Seatrout (Cynoscion nebulosus) Habitat Use in an Eastern Gulf of Mexico Estuary: The Effects of Seagrass Bed Architecture, Seagrass Species Composition, and Varying Degrees of Freshwater Influence

Wed, 14 Mar 2018 17:24:15

Spotted seatrout (Cynoscion nebulosus) are estuarine residents that have been extensively studied primarily due to their economic importance. Although spotted seatrout have a documented affinity for seagrass beds, there is little information on how seagrass bed architecture, seagrass species composition, and freshwater inflow affect this relationship. The objective of this study was to document patterns in spatiotemporal distribution and abundance of juvenile spotted seatrout (

Anaerobic Metabolism in Tidal Freshwater Wetlands: I. Plant Removal Effects on Iron Reduction and Methanogenesis

Wed, 14 Mar 2018 17:24:05

For energetic reasons, iron reduction suppresses methanogenesis in tidal freshwater wetlands; however, when iron reduction is limited by iron oxide availability, methanogenesis dominates anaerobic carbon mineralization. Plants can mediate this microbial competition by releasing oxygen into the rhizosphere and supplying oxidized iron for iron reducers. We utilized a plant removal experiment in two wetland sites to test the hypothesis that, in the absence of plants, rates of iron reduction would be diminished, allowing methanogenesis to dominate anaerobic metabolism. In both sites, methanogenesis was the primary anaerobic mineralization pathway, with iron reduction dominating only early and late in the growing season in the site with a less organic soil. These patterns were not influenced by the presence of plants, demonstrating that plants were not a key control of microbial metabolism. Instead, we suggest that site conditions, including soil chemistry, and temperature are important controls of the pathways of anaerobic metabolism.

Sustainability of a Tidal Freshwater Marsh Exposed to a Long-term Hydrologic Barrier and Sea Level Rise A Short-term and Decadal Analysis of Elevation Change Dynamics

Wed, 14 Mar 2018 17:24:04

A 115-year-old railroad levee bisecting a tidal freshwater marsh perpendicular to the Patuxent River (Maryland) channel has created a northern, upstream marsh and a southern, downstream marsh. The main purpose of this study was to determine how this levee may affect the ability of the marsh system to gain elevation and to determine the levee's impact on the marsh's long-term sustainability to local relative sea level rise (RSLR). Previously unpublished data from 1989 to 1992 showed that suspended solids and short-term sediment deposition were greater in the south marsh compared to the north marsh; wetland surface elevation change data (1999 to 2009) showed significantly higher elevation gain in the south marsh compared to the north (6 +/- 2 vs. 0 +/- 2 mm year(-1), respectively). However, marsh surface accretion (2007 to 2009) showed no significant differences between north and south marshes (23 +/- 8 and 26 +/- 7 mm year(-1), respectively), and showed that shallow subsidence was an important process in both marshes. A strong seasonal effect was evident for both accretion and elevation change, with significant gains during the growing season and elevation loss during the non-growing season. Sediment transport, deposition and accretion decreased along the intertidal gradient, although no clear patterns in elevation change were recorded. Given the range in local RSLR rates in the Chesapeake Bay (2.9 to 5.8 mm year(-1)), only the south marsh is keeping pace with sea level at the present time. Although one would expect the north marsh to benefit from high accretion of abundant riverine sediments, these results suggest that long-term elevation gain is a more nuanced process involving more than riverine sediments. Overall, other factors such as infrequent episodic coastal events may be important in allowing the south marsh to keep pace with sea level rise. Finally, caution should be exercised when using data sets spanning only a couple of years to estimate wetland sustainability as they may not be representative of long-term cumulative effects. Two years of data do not seem to be enough to establish long-term elevation change rates at Jug Bay, but instead a decadal time frame is more appropriate.

A Before-After-Control-Impact Analysis of the Effects of a Mississippi River Freshwater Diversion on Estuarine Nekton in Louisiana, USA

Wed, 14 Mar 2018 17:24:02

Since 1991, the Caernarvon Freshwater Diversion has been reintroducing Mississippi River water into a previously hydrologically isolated estuary in an effort to restore wetlands. To determine the effect of freshwater inflow on estuarine nekton community structure, a Before-After-Control-Impact study design was applied. As a result of the opening, salinities in the impact area decreased, and the nekton community structure in the estuary changed significantly. Species of economical or ecological importance either increased in biomass or exhibited no response to the opening of the diversion. Higher abundances of small fish were observed in the area receiving freshwater flow, which is an indication that the area serves as a refuge from large marine predators. Because a salinity gradient was established, as opposed to a uniform but lower salinity regime, aquatic habitat was available to nekton species from a wide spectrum of salinity tolerances.

Controlling Eutrophication along the Freshwater-Marine Continuum: Dual Nutrient (N and P) Reductions are Essential

Wed, 14 Mar 2018 17:23:46

Expanding human activities along the freshwater to marine continuum of coastal watersheds increasingly impact nutrient inputs, nutrient limitation of primary production, and efforts to reduce nutrient over-enrichment and eutrophication. Historically, phosphorus (P) has been the priority nutrient controlling upstream freshwater productivity, whereas nitrogen (N) limitation has characterized coastal waters. However, changing anthropogenic activities have caused imbalances in N and P loading, making it difficult to control eutrophication by reducing only one nutrient. Furthermore, upstream nutrient reduction controls can impact downstream nutrient limitation characteristics. Recently, it was suggested that only reducing P will effectively control eutrophication in both freshwater and coastal ecosystems. However, controls on production and nutrient cycling in estuarine and coastal systems are physically and chemically distinct from those in freshwater counterparts, and upstream nutrient management actions (exclusive P controls) have exacerbated N-limited downstream eutrophication. Controls on both nutrients are needed for long-term management of eutrophication along the continuum.

Positive Relationship between Freshwater Inflow and Oyster Abundance in Galveston Bay, Texas

Wed, 14 Mar 2018 17:23:43

Analysis of fisheries-independent data for Galveston Bay, Texas, USA, since 1985 shows eastern oysters (Crassostrea virginica) frequently demonstrate increased abundance of market-sized oysters 1 to 2 years after years with increased freshwater inflow and decreased salinity. These analyses are compared to Turner's (Estuaries and Coasts 29:345-352, 2006) study using 3-year running averages of oyster commercial harvest since 1950 in Galveston Bay. Turner's results indicated an inverse relationship between freshwater inflow and commercial harvest with low harvest during years of high inflow and increased harvest during low flow years. Oyster populations may experience mass mortalities during extended periods of high inflow when low salinities are sustained. Conversely, oyster populations may be decimated during prolonged episodes of low flow when conditions favor oyster predators, parasites, and diseases with higher salinity optima. Turner's (Estuaries and Coasts 29:345-352, 2006) analysis was motivated by a proposed project in a basin with abundant freshwater where the goal of the project was to substantially increase freshwater flow to the estuary in order to increase oyster harvest. We have the opposite concern that oysters will be harmed by projects that reduce flow, increase salinity, and increase the duration of higher salinity periods in a basin with increasing demand for limited freshwater. Turner's study and our analysis reflect different aspects of the complex, important relationships between freshwater inflow, salinity, and oysters.

Fine-Scale Detection of Estuarine Water Quality with Managed Freshwater Releases

Wed, 14 Mar 2018 17:23:21

Freshwater pulses to subtropical estuaries often occur on time scales less than 1 week. In particular, introduction of low-level pulses are potentially important during the dry season (November-April) when freshwater is scarce. Determining potential ecological benefits of pulses requires an innovative method of data acquisition at the appropriate spatial and temporal scales. The South Florida Water Management District conducted a pilot study to assess changes in water column attributes with pulse releases to the Caloosahatchee River Estuary (CRE) from January to April 2012. An average inflow of 450 cfs was targeted for a series of freshwater pulses. This study utilized an onboard, flow-through system to record surface water temperature, salinity (S), pH, dissolved oxygen, turbidity, and in situ chlorophyll a (in situ CHL) at 5 s intervals along the 42-km length of the estuary. On each of seven research cruises, the vessel stopped at multiple stations to conduct vertical water column profiles. Salinity increased throughout the CRE as inflow decreased during the study period. Simple correlation and partial least squares regression were used to determine that the downstream locations of the S = 10 isohaline and the maximum CHL concentration (in situ CHLmax) were positively related to inflow. While the in situ CHLmax was located 12-20 km downstream on five of the cruises, it was only a few kilometer from the estuary head on the first (1/12) and last (4/11) dates. It is possible that two circumstances related to freshwater inflow accounted for this pattern. First, water column stratification before January could have stimulated remineralization and primary production. Second, inflow ceased as water temperature increased to 26.0 A degrees C by April to promote algal growth. Further study of the relationships among inflow, water level, flushing time, and CHL is warranted. Future efforts will examine the range of wet season discharge by incorporating a sensor for colored dissolved organic matter to fully connect inflow, salinity, submarine light, and phytoplankton attributes in the CRE.

Anaerobic Metabolism in Tidal Freshwater Wetlands: II. Effects of Plant Removal on Archaeal Microbial Communities

Wed, 14 Mar 2018 17:23:14

The interaction of plant and microbial communities are known to influence the dynamics of methane emission in wetlands. Plant manipulations were conducted in an organic rich (JB-organic) and a mineral rich (JB-mineral) site in a tidal freshwater wetland to determine if plant removal impacted archaeal populations. In concert, a suite of process-based measurements also determined the effects of plant removal on rates of methanogenesis and Fe-reduction. The microbial populations were analyzed with clone libraries of the SSU ribosomal RNA (rRNA) gene from selected plots, and terminal restriction length polymorphism (tRFLP) of the SSU rRNA and the methyl-coenzyme M reductase (mcrA) gene. Overall, methanogenesis dominated anaerobic carbon mineralization at both sites during the most active growing season. A total of 114 SSU rRNA clones from four different plots revealed a diversity of Euryarchaeota including representatives of the Methanomicrobiales, Methanosarcinales and Thermoplasmatales. The clone libraries were dominated by the Thaumarchaeota, accounting for 65 % of clones, although their diversity was low. A total of 112 tRFLP profiles were generated from 56 samples from 25 subplots; the patterns for both SSU rRNA and mcrA showed little variation between sites, either with plant treatment or with the growing season. Overall these results suggest that wetland soil archaeal populations were resilient to changes in the associated surface plant communities. The work also revealed the presence of novel, mesophilic Thaumarchaeota of unknown metabolic function.

Detecting Freshwater Inputs via Groundwater Discharge to Marina Lagoon, Mediterranean Coast, Egypt

Wed, 14 Mar 2018 17:23:11

Much work in recent years has reported on the role of submarine groundwater discharge (SGD) on coastal biogeochemistry, but most of those studies have focused on temperate or tropical climates where year-round rainfall recharges surficial aquifers. The aim of this work, however, was to examine SGD behaviors in an arid setting-Marina Lagoon on the Egyptian Mediterranean coast. SGD was estimated via radon surveys and time-series measurements in lagoon waters during two campaigns (wet season in March 2009 and dry season in July 2010). Relatively higher values of radon were detected in March (maximum > 30 dpm/L) compared to July (up to 16 dpm/L), which would indicate either enhanced input rates, or lower mixing/atmospheric losses during the wet season. Lower salinity waters within Marina Lagoon were characterized by higher radon and higher concentrations of dissolved inorganic nitrogen (DIN) and silica (DISi), characteristic of groundwater inputs. Based on lagoon and groundwater radon measurements and an advection-diffusion model, SGD average rates between 0.83 to 2.4 x 10(8) L/day were estimated for both surveys. Since no seasonal pattern was detected, we suspect that either (1) SGD is derived from a regional aquifer not influenced by recharge from local rainfall or (2) local water use for irrigation and domestic purposes artificially recharges the surficial aquifer in the dry summer (tourist) months, which compensates for the lack of rainfall occurring at that time.

Ecosystem Responses of a Tidal Freshwater Marsh Experiencing Saltwater Intrusion and Altered Hydrology

Wed, 14 Mar 2018 17:22:23

Tidal freshwater marshes exist in a dynamic environment where plant productivity, subsurface biogeochemical processes, and soil elevation respond to hydrological fluctuations over tidal to multi-decadal time scales. The objective of this study was to determine ecosystem responses to elevated salinity and increased water inputs, which are likely as sea level rise accelerates and saltwater intrudes into freshwater habitats. Since June 2008, in situ manipulations in a Zizaniopsis miliacea (giant cutgrass)-dominated tidal freshwater marsh in South Carolina have raised porewater salinities from freshwater to oligohaline levels and/or subtly increased the amount of water flowing through the system. Ecosystem-level fluxes of CO2 and CH4 have been measured to quantify rates of production and respiration. During the first 20 months of the experiment, the major impact of elevated salinity was a depression of plant productivity, whereas increasing freshwater inputs had a greater effect on rates of ecosystem CO2 emissions, primarily due to changes in soil processes. Net ecosystem production, the balance between gross ecosystem production and ecosystem respiration, decreased by 55% due to elevated salinity, increased by 75% when freshwater inputs were increased, and did not change when salinity and hydrology were both manipulated. These changes in net ecosystem production may impact the ability of marshes to keep up with rising sea levels since the accumulation of organic matter is critical in allowing tidal freshwater marshes to build soil volume. Thus, it is necessary to have regional-scale predictions of saltwater intrusion and water level changes relative to the marsh surface in order to accurately forecast the long-term sustainability of tidal freshwater marshes to future environmental change.

A Hydrological Budget (2002-2008) for a Large Subtropical Wetland Ecosystem Indicates Marine Groundwater Discharge Accompanies Diminished Freshwater Flow

Wed, 14 Mar 2018 17:22:17

Water budget parameters are estimated for Shark River Slough (SRS), the main drainage within Everglades National Park (ENP) from 2002 to 2008. Inputs to the water budget include surface water inflows and precipitation while outputs consist of evapotranspiration, discharge to the Gulf of Mexico and seepage losses due to municipal wellfield extraction. The daily change in volume of SRS is equated to the difference between input and outputs yielding a residual term consisting of component errors and net groundwater exchange. Results predict significant net groundwater discharge to the SRS peaking in June and positively correlated with surface water salinity at the mangrove ecotone, lagging by 1 month. Precipitation, the largest input to the SRS, is offset by ET (the largest output); thereby highlighting the importance of increasing fresh water inflows into ENP for maintaining conditions in terrestrial, estuarine, and marine ecosystems of South Florida.

Water and boating activity as dispersal vectors for Schinus terebinthifolius (Brazilian pepper) seeds in freshwater and estuarine habitats

Wed, 14 Mar 2018 17:21:59

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977-2000 and its consequences for the assessment of eutrophication

Wed, 14 Mar 2018 17:21:54

Nutrients in the Western Wadden Sea: Freshwater Input Versus Internal Recycling

Wed, 14 Mar 2018 17:21:52

At present, phosphorus (P) is seen as the main limiting nutrient for phytoplankton growth in the western Wadden Sea. Six cruises were performed for water sampling at selected stations covering a full tidal cycle for later determination of dissolved and particulate nutrient concentrations. The major P sources were identified on a seasonal basis, by comparing the contribution of freshwater discharge and sediment release, calculated in a previous study, to the concentrations in the water column. A close relationship was found between the pelagic concentrations of dissolved inorganic nutrients and chlorophyll a, with a concomitant decrease in nutrients and increase in chlorophyll. This was observed in early spring and was followed by a later increase in the nutrient concentrations in spring-summer. The low concentrations found for the freshwater and seawater end-members for this period ruled out their importance as nutrient sources, suggesting that this increase resulted mainly from internal recycling in the Wadden Sea. Even though P limitation was observed during most of the year, a potential seasonal change in the limiting nutrient, from P to silica, was observed. The comparison between P supply to the Wadden Sea by freshwater discharge and sediment release showed a much higher contribution of the latter, especially in April-November. To our knowledge, this is the first study clearly presenting internal recycling as the main nutrient source to the western Wadden Sea in spring-autumn, instead of freshwater discharge or the North Sea.

Effects of Increased Salinity and Inundation on Inorganic Nitrogen Exchange and Phosphorus Sorption by Tidal Freshwater Floodplain Forest Soils, Georgia (USA)

Wed, 14 Mar 2018 17:21:33

We investigated the effects of increasing salinity and inundation on inorganic N exchange and P sorption/precipitation in soils of tidal freshwater floodplain forests (TFFF) of coastal Georgia, USA. Our objectives were to better understand how sea level rise, increasing inundation, and saltwater intrusion will affect the ability of TFFFs to retain nitrogen (N) and phosphorus (P). We collected soil cores (0-5 cm) from three TFFFs that do not currently experience saltwater intrusion and from one TFFF currently experiencing saltwater intrusion and measured NH4-N exchange and PO4-P removal over five simulated 6-h tidal cycles using nutrient-enriched freshwater (30 mu M NH4-N and 5 mu M PO4-P). In a second experiment, we exposed soil cores to three salinities (0, 2, and 5) and two inundation depths (5 and 10 cm) using the same nutrient enrichment. When flooded with nutrient-enriched freshwater, soils from the three TFFFs that do not experience saltwater intrusion removed inorganic N and P in amounts ranging from 5.2 to 10.7 and 2.3 to 4.4 mg/m(2), respectively, and the TFFF soils experiencing saltwater intrusion removed 2.1 to 3.8 mg P/m(2). However, TFFF soils experiencing saltwater intrusion released inorganic N to the water column in amounts ranging from 7.1 to 67.5 mg/m(2). In the second experiment, soils from TFFFs not experiencing saltwater intrusion released NH4-N to the water column when exposed to 2 and 5 salinity, and the amount of N released increased with salinity and number of tidal cycles. In contrast, the same TFFF soils sorbed two and three times more PO4-P when exposed to 2 and 5 salinity than when exposed to 0 salinity. P removal on a mass basis was greater under 10 cm of inundation, but the efficiency of removal was greater under the 5 cm flooding depth. Our findings suggest that saltwater intrusion caused by sea level rise will promote N release into the water column through organic matter mineralization and/or ion exchange and may promote P sorption, or precipitation of P with metal cations. In addition, release of N and resulting increased N/P could exacerbate eutrophication of estuaries in the future.

Projected Reorganization of Florida Bay Seagrass Communities in Response to the Increased Freshwater Inflow of Everglades Restoration

Wed, 14 Mar 2018 17:21:23

Historic changes in water-use management in the Florida Everglades have caused the quantity of freshwater inflow to Florida Bay to decline by approximately 60% while altering its timing and spatial distribution. Two consequences have been (1) increased salinity throughout the bay, including occurrences of hypersalinity, coupled with a decrease in salinity variability, and (2) change in benthic habitat structure. Restoration goals have been proposed to return the salinity climates (salinity and its variability) of Florida Bay to more estuarine conditions through changes in upstream water management, thereby returning seagrass species cover to a more historic state. To assess the potential for meeting those goals, we used two modeling approaches and long-term monitoring data. First, we applied the hydrological mass balance model FATHOM to predict salinity climate changes in sub-basins throughout the bay in response to a broad range of freshwater inflow from the Everglades. Second, because seagrass species exhibit different sensitivities to salinity climates, we used the FATHOM-modeled salinity climates as input to a statistical discriminant function model that associates eight seagrass community types with water quality variables including salinity, salinity variability, total organic carbon, total phosphorus, nitrate, and ammonium, as well as sediment depth and light reaching the benthos. Salinity climates in the western sub-basins bordering the Gulf of Mexico were insensitive to even the largest (5-fold) modeled increases in freshwater inflow. However, the north, northeastern, and eastern sub-basins were highly sensitive to freshwater inflow and responded to comparatively small increases with decreased salinity and increased salinity variability. The discriminant function model predicted increased occurrences of Halodule wrightii communities and decreased occurrences of Thalassia testudinum communities in response to the more estuarine salinity climates. The shift in community composition represents a return to the historically observed state and suggests that restoration goals for Florida Bay can be achieved through restoration of freshwater inflow from the Everglades.

Tidal nitrogen exchanges across a freshwater wetland succession gradient in the upper Cooper River, South Carolina

Wed, 14 Mar 2018 17:21:06

Rethinking the Freshwater Eel: Salt Marsh Trophic Support of the American Eel, Anguilla rostrata

Wed, 14 Mar 2018 17:20:56

Despite the fact that Anguilla rostrata (American eel) are frequently captured in salt marshes, their role in salt marsh food webs and the influence of human impacts, such as tidal restrictions, on this role remains unclear. To better understand salt marsh trophic support of A. rostrata, eels were collected from tidally restricted and unrestricted salt marsh creeks within three New England estuaries. Gut contents were examined, and eel muscle tissue was analyzed for carbon and nitrogen stable isotope values and entered into MixSir mixing models to understand if salt marsh food sources are important contributors to eel diet. Data suggest that eel prey rely heavily on salt marsh organic matter and eels utilize salt marsh secondary production as an energetic resource over time, and thus can be considered salt marsh residents. Gut contents indicate that A. rostrata function as top predators, feeding primarily on secondary consumers including other fish species, crustaceans, and polychaetes. Higher A. rostrata trophic position measured upstream of reference creeks suggests that severe tidal restrictions may result in altered food webs, but it is not clear how this impacts the overall fitness of A. rostrata populations in New England salt marshes.

Periodicity in Stem Growth and Litterfall in Tidal Freshwater Forested Wetlands: Influence of Salinity and Drought on Nitrogen Recycling

Wed, 14 Mar 2018 17:20:40

Many tidally influenced freshwater forested wetlands (tidal swamps) along the south Atlantic coast of the USA are currently undergoing dieback and decline. Salinity often drives conversion of tidal swamps to marsh, especially under conditions of regional drought. During this change, alterations in nitrogen (N) uptake from dominant vegetation or timing of N recycling from the canopy during annual litter senescence may help to facilitate marsh encroachment by providing for greater bioavailable N with small increases in salinity. To monitor these changes along with shifts in stand productivity, we established sites along two tidal swamp landscape transects on the lower reaches of the Waccamaw River (South Carolina) and Savannah River (Georgia) representing freshwater (a parts per thousand currency sign0.1 psu), low oligohaline (1.1-1.6 psu), and high oligohaline (2.6-4.1 psu) stands; the latter stands have active marsh encroachment. Aboveground tree productivity was monitored on all sites through monthly litterfall collection and dendrometer band measurements from 2005 to 2009. Litterfall samples were pooled by season and analyzed for total N and carbon (C). On average between the two rivers, freshwater, low oligohaline, and high oligohaline tidal swamps returned 8,126, 3,831, and 1,471 mg N m(-2) year(-1), respectively, to the forest floor through litterfall, with differences related to total litterfall volume rather than foliar N concentrations. High oligohaline sites were most inconsistent in patterns of foliar N concentrations and N loading from the canopy. Leaf N content generally decreased and foliar C/N generally increased with salinization (excepting one site), with all sites being fairly inefficient in resorbing N from leaves prior to senescence. Stands with higher salinity also had greater flood frequency and duration, lower basal area increments, lower tree densities, higher numbers of dead or dying trees, and much reduced leaf litter fall (103 vs. 624 g m(-2) year(-1)) over the five study years. Our data suggest that alternative processes, such as the rate of decomposition and potential for N mineralization, on tidal swamp sites undergoing salinity-induced state change may be more important for controlling N biogeochemical cycling in soils than differences among sites in N loading via litterfall.

Concentration-dependent Stable Isotope Analysis of Consumers in the Upper Reaches of a Freshwater-dominated Estuary: Apalachicola Bay, FL, USA

Wed, 14 Mar 2018 17:20:25

The goals of this study were to quantify organic matter source utilization by consumers in the freshwater-dominated region (East Bay) of a high river flow estuary and compare the results to consumers in marine-influenced sites of the same estuary to understand how organic matter utilization by consumers may be changing along the salinity gradient. We used the results from these evaluations to establish the baseline against which we isotopically determined trophic level for consumers in East Bay. Average isotope values for consumers sampled in East Bay ranged from -20.1aEuro degrees to -24.8aEuro degrees for carbon and from 8.9aEuro degrees to 14.3aEuro degrees for sulfur. These values were well-constrained by the four identified sources: plankton, benthic organic matter, macroalgae, and terrestrial detritus. Application of a concentration-corrected mixing model resulted in contributions of benthic production and detrital sources (averaged over the food web) to East Bay consumers of 41% and 33%, respectively, with the remainder made up of plankton and benthic macroalage. While benthic organic matter was an important organic matter source for consumers at both sites, we found that the influence of terrestrial detritus varied significantly throughout the bay. Terrestrial detritus contributed only 18% of average total organic matter in organisms inhabiting marine-influenced sites. Although terrestrial detritus did contribute to all consumers examined, most fish species in Apalachicola Bay reflect a greater reliance on autochthonous sources. Our results suggest that, while terrestrial detritus does appear to be a major contributor to commercially important shellfish species (most notably oysters and penaeid shrimp), it is not the major source fueling the diversity of secondary production in Apalachicola Bay. Thus, production in Apalachicola Bay is highly dependent on riverine influx in two ways: (1) economically important bivalves and crustaceans are being fueled by terrestrial organic matter supplied by river flooding and (2) secondary and above consumer fish species are supported by in situ production which, in turn, is reliant on nutrients supplied by the Apalachicola River. These findings are significant in light of decisions regarding water usage and river flow restrictions in the Apalachicola-Chattahoochee-Flint drainage basin. The results of this study confirm that in situ estuarine organic matter is the dominant source supporting secondary production in this river-dominated estuary.

Determining Spatial and Temporal Inputs of Freshwater, Including Submarine Groundwater Discharge, to a Subtropical Estuary Using Geochemical Tracers, Biscayne Bay, South Florida

Wed, 14 Mar 2018 17:20:19

Geochemical mixing models were used to decipher the dominant source of freshwater (rainfall, canal discharge, or groundwater discharge) to Biscayne Bay, an estuary in south Florida. Discrete samples of precipitation, canal water, groundwater, and bay surface water were collected monthly for 2 years and analyzed for salinity, stable isotopes of oxygen and hydrogen, and Sr2+/Ca2+ concentrations. These geochemical tracers were used in three separate mixing models and then combined to trace the magnitude and timing of the freshwater inputs to the estuary. Fresh groundwater had an isotopic signature (delta O-18 = -2.66aEuro degrees, delta D -7.60aEuro degrees) similar to rainfall (delta O-18 = -2.86aEuro degrees, delta D = -4.78aEuro degrees). Canal water had a heavy isotopic signature (delta O-18 = -0.46aEuro degrees, delta D = -2.48aEuro degrees) due to evaporation. This made it possible to use stable isotopes of oxygen and hydrogen to separate canal water from precipitation and groundwater as a source of freshwater into the bay. A second model using Sr2+/Ca2+ ratios was developed to discern fresh groundwater inputs from precipitation inputs. Groundwater had a Sr2+/Ca2+ ratio of 0.07, while precipitation had a dissimilar ratio of 0.89. When combined, these models showed a freshwater input ratio of canal/precipitation/groundwater of 37%:53%:10% in the wet season and 40%:55%:5% in the dry season with an error of +/- 25%. For a bay-wide water budget that includes saltwater and freshwater mixing, fresh groundwater accounts for 1-2% of the total fresh and saline water input.

Is the Response of Estuarine Nekton to Freshwater Flow in the San Francisco Estuary Explained by Variation in Habitat Volume?

Wed, 14 Mar 2018 17:20:18

Abundance of estuarine biota can vary with freshwater inflow through several mechanisms. One proposed mechanism is that the extent of physical habitat for an estuarine species increases with flow. We estimated the contribution of variation in habitat volume to the responses of eight species of estuarine nekton to changes in freshwater flow in the San Francisco Estuary. Resource selection functions for salinity and depth were developed for each species (and for five additional species) using five monitoring data sets. The TRIM3D hydrodynamic model was run for five steady flow scenarios to determine volume by salinity and depth, and resource selection functions were used as a weighting factor to calculate an index of total habitat for each species at each flow. The slopes of these habitat indices vs. flow were consistent with slopes of abundance vs. flow for only two of the species examined. Therefore, other mechanisms must underlie responses of abundance to flow for most species.

Spatiotemporal Variation of Trace Elements and Stable Isotopes in Subtropical Estuaries: I. Freshwater Endmembers and Mixing Curves

Wed, 14 Mar 2018 17:20:03

Understanding spatial and temporal variation in chemical constituents across salinity gradients is essential for using proxies to track riverine inflow, mixing processes, and migration of mobile fauna. We analyzed the freshwater endmembers and mixing curves of a suite of trace element concentrations (Mg, Ca, Mn, Sr, and Ba) and stable isotope ratios (delta O-18 and Sr-87/Sr-86) in tributaries and estuaries of the south Texas coastal bend region. While Sr/Ca and Sr-87/Sr-86 were consistent across tributaries due to the dominance of carbonate bedrock underlying the region, Ba/Ca showed some river-specific variation perhaps due to upstream urbanization. In contrast, both Mn/Ca and delta O-18 showed a high degree of variability between 2 years due to their sensitivity to redox conditions and net evaporation, respectively. Mixing curves for Ca and Sr were moderately curvilinear, suggesting the potential importance of alternative processes altering mixing relationships, such as submarine groundwater discharge (SGD). Mixing of Mg was linear and consistent with conservative behavior, while Ba showed a low salinity peak and there was no apparent mixing relationship for Mn. Mixing of Sr-87/Sr-86 was curvilinear as expected, although the steepness of the mixing curve was lower than expected under linear mixing assumptions, further indicating the possible influence of SGD. Unexpectedly, delta O-18 values were elevated above marine values across the entire salinity gradient, perhaps due to drought conditions during the sampling period. Together, these results point to the individualistic spatiotemporal dynamics of chemical constituents and illustrate the care that must be taken when choosing an appropriate proxy for salinity.

Nitrogen and Phosphorus Differentially Affect Annual and Perennial Plants in Tidal Freshwater and Oligohaline Wetlands

Wed, 14 Mar 2018 17:19:49

To test species composition and biomass responses to excess nutrients, herbaceous plants of tidal freshwater and oligohaline wetlands in a Chesapeake Bay subestuary were fertilized with nitrogen (N), phosphorus (P), both N and P (N + P), or not fertilized (Control) for 4 years. In marshes, the N treatment increased abundance measures of perennials but decreased those of annuals while the P treatment increased annuals and decreased perennials. In swamps, however, perennials increased in response to P. Total herbaceous aboveground biomass production was not limited by N, P, or N + P in marshes or swamps. These findings suggest that annual species are more susceptible than perennials to P limitation, possibly due to lack of a large perenniating root organ and lower susceptibility to mycorrhizal inoculation. Furthermore, eutrophication effects are likely to vary between swamp and marsh habitats and depend on whether the dominant nutrient supplied is nitrogen or phosphorus.

Comments on Lowe et al. "Otolith Microchemistry Reveals Substantial Use of Freshwater by Southern Flounder in the Northern Gulf of Mexico"

Wed, 14 Mar 2018 17:19:43

Lowe et al. (Estuaries and Coasts, 34:630-639, 2011) hypothesized that juvenile southern flounder Paralichthys lethostigma (Jordan and Gilbert 1884) would migrate from the Gulf of Mexico into the Mobile-Tensaw River Delta (AL, USA) and use low-salinity (oligohaline/freshwater) habitats during, at least, a portion of their first year of life. Thus, they analyzed the Sr/Ca ratio profiles along the sagittal otoliths of southern flounder collected in the Mobile-Tensaw River Delta and observed that one third of the flounders had low Sr/Ca levels in the otoliths' core and throughout the otolith, suggesting that these fishes hatched in freshwater or low-salinity habitats where they spend the majority of their life. The other two thirds of southern flounder showed high levels of Sr/Ca ratio in the otoliths' core following a marked decline of Sr/Ca ratio, which then maintained along the remainder of the otolith. This pattern was interpreted as larvae hatched in higher salinity waters before entering the Mobile-Tensaw River Delta; however, in this paper, I list several arguments to support an alternative interpretation for this pattern. I suggest that the high levels of Sr/Ca ratios in the otoliths' core of southern flounder does not reflect the saline conditions where larvae hatched, instead it reflects the location where the female progenitor hydrated the eggs. Thus, adding my interpretation on the data of Lowe et al. (Estuaries and Coasts, 34:630-639, 2011), it seems that southern flounder might hatch in or near freshwater habitats and the migration of southern flounder into an estuarine ecosystem to spawn might exist.

Mainstem and Backwater Fish Assemblages in the Tidal Caloosahatchee River: Implications for Freshwater Inflow Studies

Wed, 14 Mar 2018 17:19:34

Research strategies for investigating the freshwater-inflow requirements of estuarine fishes often integrate life-history information and correlative analyses of inflow and fish abundance. In tidal rivers, however, some fish have affinities for embayments, oxbows, and smaller tributaries, often referred to collectively as river "back-waters". The objective of this study was to determine whether freshwater and estuarine fish assemblages differed between backwaters and the mainstem of the tidal Caloosahatchee River, a highly managed river system located in an urban setting in southwest Florida. Nonmetric multidimensional scaling of 21.3-m seine data revealed that fish assemblages did indeed differ between the backwater and mainstem habitats in each of three river sections. Univariate analyses identified species that differed in abundance between the habitats, which included ecologically and economically important fishes in the region. For example, striped mullet Mugil cephalus and pinfish Lagodon rhomboides were more abundant along the river's mainstem; common snook Centropomus undecimalis and bluegill Lepomis macrochirus were more abundant in the river's backwaters. For those species that were more abundant along the mainstem of the river or showed no difference, studies that measure changes in the distribution and abundance of these species with varying inflow along the mainstem of the river are justified. However, for species that were more abundant in backwater areas, geomorphological features should be considered in the design of studies that assess factors affecting fish use.

Variation in the Flora and Fauna of Tidal Freshwater Forest Ecosystems Along the Columbia River Estuary Gradient: Controlling Factors in the Context of River Flow Regulation

Wed, 14 Mar 2018 17:19:07

Tidal freshwater forested wetlands are dynamic, complex ecosystems that typically occur in large, floodplain river estuaries throughout the world. The estuarine portion of the Columbia River, in the Pacific Northwest region of North America, is exceptionally large and extends from the Pacific Ocean to the head of tide at Bonneville Dam, located at river kilometer (RKm) 233. Our study focused on the freshwater portion of the estuarine gradient (RKm 40 to RKm 233) of the Columbia River estuary and the corresponding continuum of hydrologic regimes and biotic communities. Several diverse forested wetland community types occurred along this freshwater estuarine gradient with major shifts in community composition corresponding to the transition from predominantly tidal to predominantly fluvial hydrologic regimes. We quantitatively characterized the floristic structure, species composition, and species richness of these tidal wetlands. Additionally, we documented variation in the avifaunal and insect assemblages associated with the floral structure. We found that freshwater tidal forested wetlands in the lower reaches of the estuary were characterized by high vegetation species richness and complex forest and scrub-shrub ecosystems, while tidal wetlands in the upper reaches of the estuary displayed a greater diversity of wetland ecosystems (forested, scrub-shrub, emergent, and aquatic bed) but comparatively lower species richness. A transitional area in the mid-estuary contained forested wetlands that exhibited some similarities to estuarine forested wetlands in both the upper and lower reaches. Likewise, avifauna and insect assemblage composition transitioned along the tidal freshwater estuarine gradient. Differences in geomorphological and hydrological regimes along the estuarine gradient appear to be the factors controlling the variation in tidal freshwater forested wetland characteristics and species composition. A thorough understanding of this complex and understudied system is necessary for predicting the potential impacts of hydrologic regime alterations and climate change and for guiding ongoing restoration efforts in the region.

Increasing Severity of Phytoplankton Nutrient Limitation Following Reductions in Point Source Inputs to the Tidal Freshwater Segment of the James River Estuary

Wed, 14 Mar 2018 17:19:02

We conducted monthly bioassay experiments to characterize light and nutrient use efficiency of phytoplankton communities from the chlorophyll-a maximum located in the tidal freshwater region of the James River Estuary. Bioassay results were interpreted in the context of seasonal and inter-annual variation in nutrient delivery and biomass yield using recent and long-term data. Bioassay experiments suggest that nutrient limitation of phytoplankton production has increased over the past 20 years coinciding with reductions in point source inputs and estuarine dissolved nutrient concentrations. Despite increasing nutrient stress, chlorophyll concentrations have not declined due to more efficient nutrient usage. Greater CHLa yield (per unit of N and P) may be due to feedback mechanisms by which the presence of toxin-producing cyanobacteria inhibits grazing by benthic and pelagic filter-feeders. Seasonal patterns in nutrient limitation indicate that phytoplankton in the James respond to variations in inflow concentrations of dissolved nutrients. This association gives rise to an atypical pattern whereby the severity of nutrient limitation diminishes with low discharge in late summer due to minimal dilution of local point sources inputs by riverine discharge. We suggest that this may be a common feature of estuaries located in proximity to urbanized areas.

Factors Determining the Location of the Chlorophyll Maximum and the Fate of Algal Production within the Tidal Freshwater James River

Wed, 14 Mar 2018 17:18:41

Longitudinal variation in factors affecting phytoplankton production were analyzed to better understand the mechanisms that cause the formation of a chlorophyll maximum within the tidal freshwater James River. Phytoplankton production was two- to threefold higher in the region where persistent elevated chlorophyll concentrations occurred. Near this site, the morphology of the James transitions from a narrow, deep channel to a broad expanse with shallow areas adjoining the main channel. Shallower depths resulted in greater average irradiance within the water column and suggest that release from light limitation was the principal factor accounting for the location of the chlorophyll maximum. Grazing rates were low indicating that little of the algal production was directly consumed by zooplankton. Low exploitation by zooplankton was attributed to poor food quality due to high concentrations of non-algal particulate matter and potential presence of cyanobacteria. Metabolism data suggest that two thirds of net primary production was respired in the vicinity of the chlorophyll maximum and one third was exported via fluvial and tidal advection. Comparison of water column and ecosystem metabolism indicates that the bulk of respiration occurred within the sediments and that sedimentation was the dominant loss process for phytoplankton.

Sediment Accretion in Tidal Freshwater Forests and Oligohaline Marshes of the Waccamaw and Savannah Rivers, USA

Wed, 14 Mar 2018 17:18:03

Sediment accretion was measured at four sites in varying stages of forest-to-marsh succession along a fresh-to-oligohaline gradient on the Waccamaw River and its tributary Turkey Creek (Coastal Plain watersheds, South Carolina) and the Savannah River (Piedmont watershed, South Carolina and Georgia). Sites included tidal freshwater forests, moderately salt-impacted forests at the freshwater-oligohaline transition, highly salt-impacted forests, and oligohaline marshes. Sediment accretion was measured by use of feldspar marker pads for 2.5 year; accessory information on wetland inundation, canopy litterfall, herbaceous production, and soil characteristics were also collected. Sediment accretion ranged from 4.5 mm year(-1) at moderately salt-impacted forest on the Savannah River to 19.1 mm year(-1) at its relict, highly salt-impacted forest downstream. Oligohaline marsh sediment accretion was 1.5-2.5 times greater than in tidal freshwater forests. Overall, there was no significant difference in accretion rate between rivers with contrasting sediment loads. Accretion was significantly higher in hollows than on hummocks in tidal freshwater forests. Organic sediment accretion was similar to autochthonous litter production at all sites, but inorganic sediment constituted the majority of accretion at both marshes and the Savannah River highly salt-impacted forest. A strong correlation between inorganic sediment accumulation and autochthonous litter production indicated a positive feedback between herbaceous plant production and allochthonous sediment deposition. The similarity in rates of sediment accretion and sea level rise in tidal freshwater forests indicates that these habitats may become permanently inundated if the rate of sea level rise increases.

The Influence of Freshwater on Nekton Community Structure in Hydrologically Distinct Basins in Northeastern Florida Bay, FL, USA

Wed, 14 Mar 2018 17:17:55

Natural patterns of freshwater delivery to the Florida Bay estuary have been disrupted by flood-control and water-supply projects. Restoration efforts are likely to alter salinity regimes and patterns of nekton distribution and abundance. Spatial and seasonal community structure differences were analyzed for small-bodied and large-bodied nekton collected by fisheries-independent monitoring from 2006 through 2009 in the northeastern basins of Florida Bay. The small-bodied nekton community was dominated by resident fish that may be indicators of ecosystem health because they spend their lives within the bay and are not directly influenced by human harvest; the large-bodied nekton community was dominated by transient and, in some cases, economically important species. Differences in community structure revealed a gradient in similarity that was associated with freshwater influence, as determined by salinity variability over the study period. These observed changes associated with salinity regimes within and between basins underscore the importance of monitoring communities before and after alterations in freshwater inflow.

Assessment of Biotic Integrity of the Coastal Freshwater Tidal Zone of a Temperate Estuary of South America through Multiple Indicators

Wed, 14 Mar 2018 17:17:48

The aim of this study was to propose an index [Index of Biotic Integrity for the Rio de la Plata (IBIRP)] formulated from a minimum of information-rich metrics related to biological integrity for evaluation of the coastal freshwater tidal zone of the Rio de la Plata estuary. A total of 23 sites were selected along 170 km of shoreline (34A degrees 27'10aEuro(3) S, 58A degrees 30'21aEuro(3) W and 35A degrees 23'28aEuro(3) S, 57A degrees 08'50aEuro(3) W), being influenced by different land uses. We explored 36 biotic descriptors (designated candidate metrics), each of which is considered as an environmental indicator, and selected four metrics: two related to phytoplankton assemblage (planktonic cyanobacterial density and phytoplanktonic total density) and two linked to benthic assemblages, the diatoms (percent most tolerant taxa), and the invertebrates (percent Tanaidacea). The metrics that were chosen to integrate the IBIRP provide valuable information about the biotic integrity both in terms of time and space. The multimetric index can assume values between 0 (very bad status) and

Response to "Comment on 'Otolith Microchemistry Reveals Substantial Use of Freshwater by Southern Flounder in the Northern Gulf of Mexico'" by Pedro Morais

Wed, 14 Mar 2018 17:17:45

Lowe et al. (Estuar Coast 34:630-639, 2011) used Sr/Ca in the otoliths of juvenile southern flounder (Paralichthys lethostigma) to demonstrate the importance of low-salinity habitats in the northern Gulf of Mexico during early life. While otolith cores indicated that most southern flounder originated in high-salinity environments (elevated Sr/Ca in otolith core) and moved into lower salinity habitats (decreased Sr/Ca outside of the otolith core), approximately one third of the sampled individuals had otolith core chemistry that indicated spawning or hatching in or near freshwater habitats (low Sr/Ca throughout the otolith). Morais (Estuar Coast 34:630-639, 2012) proposes a different interpretation: he suggests that the high Sr/Ca found in 68 % of juvenile otolith cores (and low Sr/Ca just outside of the core region) may be due to females hydrating their eggs in offshore (high-salinity) waters, with spawning, hatching, and egg/larval development all actually occurring in low-salinity environments (his "sea-run mother" hypothesis). While there is ample literature supporting the importance of maternal contributions to otolith microchemistry during vitellogenesis, it is our contention that such contributions ultimately depend on the ecology and reproductive physiology of each species. Further, a mass inshore migration of adult southern flounder during their spawning season is counter to the well-documented life history patterns for this species throughout its range. While we appreciate Morais' perspective, we continue to stand by the conclusion of our original paper.

Nitrogen budget for low and high freshwater inflows, Nueces Estuary, Texas

Wed, 14 Mar 2018 15:58:16

Nueces Estuary is a relatively shallow, microtidal estuary which receives inputs from a significant industrial and urban area and from a semi-arid drainage basin. Nitrogen (N) loadings were compiled using FLUX model and flow X concentration calculations for four annual periods spanning a range of inflow volumes. For each annual period, N budgets were developed, supported by water and total dissolved solids budgets. Budget compilations include materials transported in tidal exchange with the Gulf of Mexico and with neighboring bays. Wastewater discharge contributes twice as much N to the bay than inflows from the Nueces River. Net flows and tidal entrainment of materials from neighboring bays contribute 24-32% of total loadings except during flood flows of the Nueces River. Atmospheric deposition to the estuary surface provides 8% of N loading. Despite low tidal amplitude and a restricted Gulf pass, tidal entrainment losses are the main vehicle of export, except during flood flows, when net flows to the Gulf become important. The system exports much more of its total N load than would be expected from its water residence time, possibly facilitated by ship channel longitudinal transport. Denitrification accounts for 30-40% of all N lost. Uncertainties in components of the budget are estimated and included in compilations of confidence bounds for N budget components.

Hydrodynamics of suspended particulate matter in the tidal freshwater zone of a macrotidal estuary (the Seine estuary, France)

Wed, 14 Mar 2018 15:58:08

The effects of fortnightly, semidiurnal, and quaterdiurnal lunar tidal cycles on suspended particle concentrations in the tidal freshwater zone of the Seine macrotidal estuary were studied during periods of medium to low freshwater flow. Long-term records of turbidity show semidiurnal:and spring-neap erosion-sedimentation cycles. During spring tide, the rise in low tide levels in the upper estuary leads to storage of water in the upper estuary. This increases residence time of water and suspended particulate matter (SPM). During spring tide periods, significant tidal pumping, measured by flux calculations, prevents SPM transit to the middle estuary which is characterized by the turbidity maximum zone. On a long-term basis, this tidal pumping allows marine particles to move upstream for several tens of kilometers into the upper estuary. At the end of the spring tide period, when the concentrations of suspended particulate matter are at their peak values and the low-tide level drops, the transport of suspended particulate matter to the middle estuary reaches its highest point. This period of maximum turbidity is of short duration because a significant amount of the SPM settles during neap tide. The particles, which settle under these conditions, are trapped in the upper estuary and cannot be moved to the zone of maximum turbidity until the next spring tide. From the upper estuary to the zone of maximum turbidity, particulate transport is generated by pulses at the start of the spring-map tide transition period.

Freshwater inundation effects on emergent vegetation of a hypersaline salt marsh

Wed, 14 Mar 2018 15:57:52

The coastal marshlands of the Nueces estuary, Texas depend upon periodic freshwater inundation to support current community structure arid promote further establishment and expansion of emergent halophytes. Decades of watershed modifications have dramatically decreased freshwater discharge into the upper estuary resulting in hypersaline and dry conditions. In an attempt to partially restore inflow, the U.S. Bureau of Reclamation excavated two overflow channels re-connecting the Nueces River to the marshlands. Freshwater-mediated (precipitation and inflow) changes in tidal creek and porewater salinity and emergent marsh vegetation were examined over a 5-yr period at three stations in the upper Nueces Marsh with the aid of a Geographical Information System (GIS). Two stations were potentially subjected to freshwater inflow through the channels, while one station experienced only precipitation. Decreased tidal creek and porewater salinity were significantly correlated with increased freshwater at all stations (R(2) = 0.37 to 0.56), although porewater salinities remained hypersaline. GIS analyses indicated the most considerable vegetation change following freshwater inundation was increased cover of the annual succulent Salicornia bigelovii. Fall inundation allowed seed germination and rapid expansion of this species into previously bare areas during the subsequent winter and following spring. The station affected by both inflow and precipitation exhibited greater S. bigelovii cover than the station affected solely by precipitation in both spring 1999 (58.7% compared to 27.9%) and 2000 (48.6% compared to 1.9%). Percent cover of the perennial Batis maritima temporarily increased after periods of consistent rainfall. The response was short term, and cover quickly returned to pre-inundation conditions within 3 mo. Prolonged inundation led to long-term (>2 yr) decreases in percent cover of B. maritima. Our results suggest that the timing and quantity of freshwater inundation strongly dictate halophyte response to precipitation and inflow. Brief periods of freshwater inundation that occur at specific times of year alleviate stress and promote seed germination and growth, but extended soil saturation can act as a disturbance that has a negative impact on species adapted to hypersaline conditions.

Productivity and biomass of the seagrass Thalassia testudinum along a gradient of freshwater influence in Charlotte Harbor, Florida

Wed, 14 Mar 2018 15:57:41

Eight meadows of the seagrass Thalassia testudinum Banks err, Konig representing a gradient of freshwater influence in Charlotte Harbor, Florida (United States), were sampled on it bimonthly basis from April 1995 to August 1996. Spatial and temporal variation in the density, biomass, productivity, and epiphyte loads of short shoots were determined. Physical factors such as water temperature, salinity, and light extinction coefficients were also measured. Areal blade production (g dw m(-2) d(-1)) of T, testudinum was not strongly associated with water temperature, salinity, or the amount of subsurface irradiance reaching the bottom at each station. Variation in production could be described by a linear combination of the independent variables water temperature and salinity. Water clarity (expressed as the percent of subsurface irradiance reaching the bottom) was positively related to salinity The lack of a clear relationship between water clarity and areal production was probably due to water clarity being highest during times of the year when water temperatures were too cold to support growth of T. testudinum. Our results suggest that seagrass light requirements determined by averaging irradiance levels measured during the growing season might be more relevant than those established by averaging light measurements collected throughout the year. The use of field studies for estimating lower salinity tolerances of seagrasses might be inappropriate for those systems where water clarity is positively associated with salinity.

Nekton use of submerged aquatic vegetation, marsh, and shallow unvegetated bottom in the Atchafalaya River Delta, a Louisiana tidal freshwater ecosystem

Wed, 14 Mar 2018 15:57:22

We sampled nekton (fishes and decapod crustaceans) in submerged aquatic vegetation (SAV) (Potamogeton nodosus, Najas guadalupensis), in emergent marsh vegetation (Sagittaria spp. and Scirpus americanus), and over unvegetated bottom associated with three islands in the Atchafalaya River Delta, Louisiana. The purpose of our study was to quantify nekton densities in these major aquatic habitat types and to document the relative importance of these areas to numerically dominant aquatic organisms. We collected a total of 33 species of fishes and 7 species of crustaceans in 298 1-m(2) throw trap samples taken over three seasons: summer (July and August 1994), fall (September and October 1994), and spring (May and June 1995). Fishes numerically accounted for > 65% of the total organisms collected. Vegetated areas generally supported much higher nekton densities than unvegetated sites, although bay anchovies Anchoa mitchilli were more abundant over unvegetated bottom than in most vegetated habitat types. Among vegetation types, most species showed no apparent preference between SAV and marsh. However, inland silversides Menidia beryllina and freshwater gobies Gobionellus shufeldti were most abundant in Scirpus marsh in summer, and blue crabs Callinectes sapidus were most abundant in SAV (Potamogeton) in spring. Several species (sheepshead minnow Cyprinodon variegatus, rainwater killifish Lucania parva, and blue crab) apparently selected the vegetated backmarsh of islands (opposite of riverside) over streamside Scirpus marsh. Freshwater gobies, in contrast, were most abundant in streamside Scirpus marsh. Densities of juvenile blue crabs were high (up to 17 m(-2)) in vegetated delta habitat types and comparable to values reported from more saline regions of Gulf Coast estuaries. Shallow vegetated habitat types of the Atchafalaya River Delta and other tidal freshwater systems of the Gulf Coast may be: important nursery areas for blue crabs and other estuarine species.

Physiological responses of transplants of the freshwater angiosperm Vallisneria americana along a salinity gradient in the Caloosahatchee Estuary (Southwestern Florida)

Wed, 14 Mar 2018 15:55:20

Fluctuations in freshwater input may affect the physiology and survival of submerged aquatic vegetation (SAV) occurring in oligoaline to mesohaline estuarine regions. Controls on the distribution of the freshwater angiosperm Vallisneria americana, were investigated by transplanting ramets. Pots (3.8-1) containing ramets were distributed among four sites (upstream site [least saline], donor site, near downstream site, and far downstream site [most saline]) in the Caloosahatchee Estuary (Southwest Florida) during wet (May-August) and dry (October-February) seasons. During 2-4 mo of each season, physiological indicators were monitored, including photosynthesis, glutamine synthetase activity, and protein content in shoots, and carbohydrates and total nitrogen and carbon in shoot and subterranean tissues. Where the physical environment (light or salinity) was suboptimal, all physiological indices, except photosynthetic rate, showed similar stress responses, which ranged from a slow decline to a rapid drop in physiological function. Levels of soluble carbohydrates decreased in response to unfavorable conditions more rapidly than did insoluble carbohydrates. Shoot protein of V. americana declined prior to transplant death, suggesting that measuring protein content may provide a rapid assessment of physiological health. V. americana transplants at the low-salinity upstream site died during both wet and dry season experiments, likely in response to light limitation and/or partial burial by sediments. At the far downstream site, death occurred within 2-4 wk, and was attributable to elevated salinities (> ca. 15 parts per thousand). Comparison of physiological responses with salinity and light regimes at the donor and near downstream sites suggest that light may ameliorate salinity stress. This study demonstrates that V: americana, nominally classed as a freshwater macrophyte, is capable of a remarkable degree of halotolerance.

Sedimentation cycles in a river-mouth tidal freshwater marsh

Wed, 14 Mar 2018 15:55:20

Tidal freshwater marshes are critical buffers that exist at the interface between watersheds and estuaries. Little is known about the physical dynamics of tidal freshwater marsh evolution. Over a 21-mo period, July 1995 to March 1997, measurements were made of biweekly sediment deposition at 23 locations in a 3.8-ha tidal freshwater marsh in the Bush River subestuary of the upper Chesapeake Bay. Biweekly accumulation showed high spatial and temporal variability, ranging from -0.28 g cm(-2) to 1.15 g cm(-2). Spatial variability is accounted for by habitat differences including plant associations, elevation, and hydrology. Temporal variability is accounted for by interannual climate variability, the growth cycles of marsh plants, stream marsh interactions, forest-marsh interactions, and animal activity.

Interactive effects of animal disturbance and elevation on vegetation of a tidal freshwater marsh

Wed, 14 Mar 2018 15:54:37

We studied interactions between animal disturbance (geese, carp, and muskrat) and elevation in a field experiment in tidal freshwater marshes of the Patuxent River, Maryland, United States. Vegetation changes were recorded in fenced and unfenced plots in high and low marsh community types for 2 yr using measurements of areal cover and within-plot frequency (which were averaged to create a dominance index), Leaf Area Index (LAI), and aboveground biomass. We related tight environment to differences in vegetation using below-canopy measurements of Photosynthetically Active Radiation (PAR). In the low marsh, total cover of all species, cover of annual species, biomass, and LAI were significantly higher in plots fenced to exclude animals (exclosures) than in unfenced plots (fenced/unfenced total cover = 76/40%, annual cover = 45/10%, biomass = 936/352 g m(-2), LAI = 3.3/1.4). PAR was significantly lower in fenced than unfenced plots (fenced/unfenced = 115/442 mumol s(-1) m(-2)). Despite the strong effect of fencing on biomass, species richness per plot (i.e., the number of species per plot, or species density) was not affected significantly by fencing in the low marsh. Most of the observed differences in cover, biomass, LAI, and PAR were due to variation in the abundance of the herbaceous annual species Bidens laevis (dominance index fenced/unfenced = 45/10%) and Zhania aquatica (30/12%). In the high marsh community, fencing had only minor effects on plant community composition and did not significantly affect species richness, cover, biomass, PAR, or LAI. Our results show that animals can dramatically affect low marsh vegetation, primarily via physical disturbance or herbivory of shallowly rooted seedlings of annual species.

The loss of native biodiversity and continuing nonindigenous species introductions in freshwater, estuarine, and wetland communities of Pearl Harbor, Oahu, Hawaiian islands

Wed, 14 Mar 2018 15:53:33

The benthic invertebrates and fishes of the estuarine, lower stream areas, and wetlands of Pearl Harbor were sampled from 1997-1998 as a companion study to marine inventories conducted in Pearl Harbor. The first comprehensive assessment of the area found that nonindigenous species comprise the dominant portion of the biota. A total of 191 aquatic species in 8 phyla were identified in the estuarine reaches of Pearl Harbor. Nonindigenous species dominated and comprised 48% of the species, whereas only 33% were native and 19% were cryptogenic. Two new nonindigenous species to Hawaii were found during this study: a species of fang-toothed blenny (Omobranchus ferox) and an estuarine hydrobiid snail (Pyrgophorus cf. coronatus) introduced from the Philippine Islands and the Caribbean, respectively. No single geographic region predominates as a source of aquatic species introductions into the Pearl Harbor area, although more species come from the Americas than other areas. Fifty-seven percent originated from the Americas, 30% from Asia and the Pacific, 5% from Australia/New Zealand, 5% show a world-wide distribution, and fewer than 3% of species originated from Africa. The majority of nonindigenous species appear to arrive from five major sources: intentional and accidental aquarium releases; intentional biocontrol releases; intentional food source releases; ballast water or hull fouling releases; and brought in with airplanes. Non-native species will likely continue to increase in the freshwater and estuarine portions Pearl Harbor because of the wide variety of sources from which introductions take place.

Macroinvertebrates of a rocky shore in the freshwater tidal Hudson River

Wed, 14 Mar 2018 15:53:23

We studied the macroinvertebrate fauna of a rocky shore in the freshwater tidal Hudson River during 1992-1994, the early years of the zebra mussel (Dreissena polymorpha) invasion. The macroinvertebrate community was numerically dominated by chironomids, nematodes, oligochaetes, gastropods, zebra mussels, and planarian flatworms. The community was a mixture of species typical of stony warm water rivers and lake shores, freshwater generalists, and semiterrestrial species. Overall marroinvertebrate densities were moderate to low (2,800-14,600 m(-2)). Density was a strong function of season and elevation, with consistently low densities in the early spring and in the intertidal zone. This pattern suggests that physical harshness (alternating submergence and desiccation; ice and low temperatures) limits the distribution of invertebrates at this site. Zebra mussels occurred at our study site chiefly below the low tide mark, but only at moderate abundance (usually

Water quality analysis of a freshwater diversion at Caernarvon, Louisiana

Wed, 14 Mar 2018 15:53:18

Since 1991, Mississippi River water has been diverted at Caernarvon, Louisiana, into Breton Sound estuary. Breton Sound estuary encompasses 1100 km(2) of fresh and brackish, rapidly subsiding wetlands. Nitrite + nitrate, total Kjeldahl nitrogen, ammonium, total phosphorus, total suspended sediments, and salinity concentrations were monitored at seven locations in Breton Sound from 1988 to 1994. Statistical analysis of the data indicated decreased total Kjeldahl nitrogen with associated decrease in total nitrogen, and decreased salinity concentrations in the estuary due to the diversion. Spring and summer water quality transects indicated rapid reduction of nitrite + nitrate and total suspended sediment concentration as diverted Mississippi River water entered the estuary, suggesting near complete assimilation of these constituents by the ecosystem. Loading rates of nitrite + nitrate (5.6-13.4 g m(-2) yr(-1)), total nitrogen (8.9-23.4 g m(-2) yr(-1)), and total phosphorus (0.9-2.0 g m(-2) yr(-1)) were calculated along with removal efficiencies for these constituents (nitrite + nitrate 88-97%; total nitrogen 32-57%; total phosphorus 0-46%). The low impact of the diversion on water quality in the Breton Sound estuary, along with assimilation of TSS over a very short distance, suggests that more water may be introduced into the estuary without detrimental affects. This would be necessary if freshwater diversions are to be used to distribute nutrients and sediments into the lower reaches of the estuary, in an effort to compensate for relative sea-level rise, and reverse the current trend of rapid loss of wetlands in coastal Louisiana.

Spatial and temporal variation of the nekton and hyperbenthos from a temperate European estuary with regulated freshwater inflow

Wed, 14 Mar 2018 15:52:58

The aquatic macrofauna of the Guadalquivir estuary were sampled (1 min mesh persiana net) at 5 sampling sites located along the entire (except the tidal freshwater region) estuarine gradient of salinity (outer 50 kin). A total of 134 fish and macroinvertebrate species was collected but only 62 were considered common or regularly present in the estuary. Univariate measures of the community structure showed statistically significant differences among sampling sites: species richness, abundance, and biomass decreased in the upstream direction, being positively correlated with the salinity. Temporal differences of these three variables were also statistically significant. While a clear seasonal pattern (minimum densities in winter and maximum in spring-summer) was observed for abundance and biomass, no such pattern existed for die number of species. Mysids was the most dominant group throughout the estuary (96% to 99% of abundance; 49% to 85% of biomass), although fish biomass was also important at the outer estuary (36% to 38%). Multivariate analyses indicated highly significant spatial variation in the macrofaunal communities observed along the salinity gradient. These analyses suggest that the underlying structure was a continuum with more or less overlapping distributions of the species dependent on their ability to tolerate different physicochemical conditions. There were also significant temporal (intermonthly + interannual) variation of the estuarine community; the relative multivariate dispersion indicated that monthly variation was more considerable (relative multivariate dispersion > 1) at the outer part of the estuary during the wet year (last 20 km) and was higher in the inner stations during the dry year (32 to 50 kin from the river mouth). Since a clear negative exponential relationship was observed between the freshwater input (from a dam located 110 km upstream) and water salinity at all sampling stations, it is concluded that the human freshwater management is probably affecting the studied estuarine communities. While the higher seasonal (long-term) stability of the salinity gradient, due to the human control of the freshwater input, may facilitate the recruitment of marine species juveniles during the meteorologically unstable early-spring, the additional (short-term) salinity fluctuations during the warm period may negatively affect species that complete their lifecycle within the estuary.

Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater Delta

Wed, 14 Mar 2018 15:52:36

Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production.

On the mixing processes in estuaries: The fractional freshwater method revisited

Wed, 14 Mar 2018 15:51:57

A mathematically transparent model for long-term solute dynamics, based on an oscillating reference frame, is applied to the analysis of the mixing process in estuaries. Classical tidally-averaged transport models for estuaries, all derived in some way from the Fractional Freshwater Method of Ketchum (1951) are reinterpreted in this framework. We demonstrate that in these models, the dispersion coefficients obtained from salinity profiles are not always a good representation of the mixing intensity of other dissolved constituents. In contrast, the hypothesis of equal coefficients is always verified in our oscillating coordinate system, which is almost devoid of tidal harmonics. The mathematical representation of the seaward boundary condition is also investigated. In the tidally-averaged Eulerian models, a fixed Dirichlet boundary condition is usually imposed, a condition that corresponds to an immediate, infinite dilution of the dissolved constituent beyond the fixed estuarine mouth. This mathematical representation of the estuarine-coastal zone interface at a fixed location is compared with the case of an oscillating location, which protrudes back and forth into the sea with the tide. Results demonstrate that the mathematical representation of the seaward boundary condition has a significant influence on the resulting mixing curves. We also show how to apply our approach to the prediction of mixing curves in real estuaries.

A conceptual model of estuarine freshwater inflow management

Wed, 14 Mar 2018 15:51:50

As humans continue to influence the quantity, timing, and quality of freshwater input to estuaries, it is becoming increasingly common for policies to be enacted that mandate the establishment of freshwater inflow criteria that will serve to preserve and protect estuarine ecosystems. This paper reviews the scientific literature describing how changes in freshwater inflow affect estuaries, proposes a conceptual model that explores the roles of scientists, citizens, politicians, and managers in the management of freshwater inflow to estuaries, and uses the model to explore the ways in which freshwater inflow is managed in a variety of estuaries. The scientific review is organized to provide an overview of the connections between freshwater inflow (in terms of the quantity, quality, and timing of water delivery), estuarine conditions (such as salinity and concentrations of dissolved and particulate material), and estuarine resources (such as the distribution and abundance of organisms), and to highlight our understanding of the causative mechanisms that underlie the relationships among these variables. The premise of the conceptual model is that the goal of estuarine freshwater inflow policy is to protect those resources and functions that we as a society value in estuaries, and that management measures use scientific information about the relationships among inflow, conditions, and resources to establish inflow standards that can meet this goal. The management approach can be inflow-based (flow is kept within some prescribed bounds under the assumption that taking too much away is bad for the resources), condition-based (inflow standards are set in order to maintain specified conditions in the estuary), or resource-based (inflow standards are set based on the requirements of specific resources), but each of these is carried out by regulating inflow. This model is used as a framework to describe the development of freshwater inflow criteria for estuaries in Texas, Florida, and California.

Freshwater requirements of a semi-arid supratidal and floodplain salt marsh

Wed, 14 Mar 2018 15:50:17

When rivers are impounded, the reduction in downstream flow can produce important and often adverse effects, especially in the estuarine environment. One or more dams have been proposed for the Olifants River system in the Western Cape, South Africa. This estuary has an extensive area of salt marsh that was examined to see whether it required occasional flooding with freshwater to wash out accumulated salts. The dominant salt marsh species, Sarcocornia pillansii, occurred in supratidal and floodplain areas where the water table was shallowest, the soil moisture highest, and the soil electrical conductivity lowest. Aerial photographs and simulated runoff data showed that no flood had covered the floodplain during the previous 80 years. The data indicate that salt marsh plants use saline groundwater during the dry months of the year in order to survive, but use the short season winter rainfall period with low salinity conditions to grow and reproduce. This study demonstrated that live roots of S. pillansii reached the water table during the dry season. Tissue and soil water potentials, the relationship between vegetation cover, depth to the water table, and electrical conductivity of the groundwater support the conclusion that saline groundwater is the only source of water during the drier months of the year. Freshwater flooding of the river in winter may be important because it covers the supratidal area with less saline water and reduces the depth to the water table on the floodplain. This makes the groundwater more accessible to the halophytes growing on the floodplain.

Response times of salinity in relation to changes in freshwater inflows in the Lower Hillsborough River, Florida

Wed, 14 Mar 2018 15:49:57

The Lower Hillsborough River, Florida is a short (16 ion) riverine estuary which has a dam located at its upstream end. Salinity below the dam is influenced by freshwater that hows over or through the structure. Depending on location in the estuary, the response of salinity to changes in upstream freshwater inflows is normally not instantaneous, but lags behind the freshwater release. An analytical approach and a laterally averaged two-dimensional hydrodynamic model were used to examine the response time of salinity in the Lower Hillsborough River to changes in freshwater inflows from the upstream reservoir. A series of case studies were conducted using the model to determine how salinity in the river within one kilometer below the dam would respond to changes in freshwater inflows. The model results suggest that the time lag of salinity in the river depends on whether the upstream freshwater inflows are increasing or decreasing, as wed as their magnitude. While the time lag for salinity is about six to eight days for decreasing inflows, it is much shorter for increasing inflows depending on the magnitude of the now release.

Phytoplankton forcing by a record freshwater discharge event into a large lagoonal estuary

Wed, 14 Mar 2018 15:49:20

We report here the response of the water column and phytoplankton biomass of a large lagoonal estuary to a record freshwater discharge event which followed from extraordinary hurricane activity. In the fall of 1999, three hurricanes passed over eastern North Carolina coast in a 7-wk period: Hurricane Dennis (August 24-September 5), Hurricane Floyd (September 14-17), and Hurricane Irene (October 13-16). The hurricanes delivered record rainfall to the watersheds of the Pamlico Sound, North Carolina, the second largest estuary in North America. Hurricane Floyd was followed by a 500-yr flood that displaced 80% of the volume of the Sound and delivered half the annual nitrogen (N)-nutrient load to this N-limited system. After Hurricane Floyd, buoyancy stratification restricted the mixed layer depth, dissolved inorganic nitrogen (DIN) in surface waters increased, and surface chdorophyll biomass increased up to 4-fold. Chlorophyll biomass did not increase to the potential indicated by residual DIN because of light-limitation attributable to suspended particulates, phytoplankton pigments, and colored dissolved organic material (CDOM). The discharge waters created hydrological conditions and supplied materials that we interpret to have both stimulated and restricted phytoplankton blooms. The effects of the discharge event on the hydrology and phytoplankton of the Pamlico Sound persisted about 6 months, after which it returned to its pre-event condition, attesting to the resilience of the system.

Freshwater inflow: Science, policy, management

Wed, 14 Mar 2018 15:49:08

The papers in this special issue were presented in a special session during the 2001 biennial conference of the Estuarine Research Federation held in St. Pete Beach, Florida. The session, "Freshwater inflow: Science, policy and management," was focused on issues related to reduced freshwater inflow to estuaries. The session brought together scientists, managers, and regulators, and included presentations on the estimation of freshwater input to estuaries, development of ecological indicators to assess changes in inflow, management strategies used to set freshwater requirements, and experiences with the reintroduction of freshwater to restore inflow.

Innate immunity environmental drivers and disease ecology of marine and freshwater invertebrates

Thu, 15 Feb 2018 17:21:07

Despite progress in the past decade, researchers struggle to evaluate the hypothesis that environmental conditions compromise immunity and facilitate new disease outbreaks. In this chapter, we review known immunological mechanisms for selected phyla and find that there are critical response pathways common to all invertebrates. These include the prophenoloxidase pathway, wandering phagocytic cells, cytotoxic effector responses, and antimicrobial compounds. To demonstrate the links between immunity and the environment, we summarize mechanisms by which immunity is compromised by environmental conditions. New environmental challenges may promote emergent disease both through compromised host immunity and introduction of new pathogens. Such challenges include changing climate, polluted environment, anthropogenically facilitated pathogen invasion, and an increase in aquaculture. The consequences of these environmental issues already manifest themselves as increased mortality on coral reefs, pathogen range expansion, and transmission of disease from aquaculture to natural populations, as we summarize in a final section on recent marine epizootics.

Nutrient cycling by animals in freshwater ecosystems

Thu, 15 Feb 2018 17:18:41

Animals are important in nutrient cycling in freshwater ecosystems. Via excretory processes, animals can supply nutrients (nitrogen and phosphorus) at rates comparable to major nutrient sources, and nutrient cycling by animals can support a substantial proportion of the nutrient demands of primary producers. In addition, animals may exert strong impacts on the species composition of primary producers via effects on nutrient supply rates and ratios. Animals can either recycle nutrients within a habitat, or translocate nutrients across habitats or ecosystems. Nutrient translocation by relatively large animals may be particularly important for stimulating new primary production and for increasing nutrient standing stocks in recipient habitats. Animals also have numerous indirect effects on nutrient fluxes via effects on their prey or by modification of the physical environment. Future studies must quantify how the importance of animal-mediated nutrient cycling varies among taxa and along environmental gradients such as ecosystem size and productivity.

Time budget of Coots wintering on flooded freshwater meadows

Thu, 15 Feb 2018 16:58:18

The daily time budget of Coots Fulica atra was calculated from 36 hours of observation during January and February 1997-1999 on flooded meadows at Lake Brabrand, eastern Jutland. Groups of 5-66 Coots were scan-sampled (Altmann 1974) every three minutes for an hour. The day was divided into three time periods, 08:00-11:00, 11:00-14:00 and 14:00-17:00. Feeding and swimming were the dominant activities (Table 1) and most birds were feeding at the water surface. No differences in activity partitioning were detected among the time periods. Feeding activity, however, increased significantly from 72% in January to 78% in February.

Impact of a toxic invasive species on freshwater crocodile (Crocodylus johnstoni) populations in upstream escarpments

Mon, 5 Feb 2018 15:37:46

Context. Spread of the invasive cane toad (Rhinella marina) across northern Australia is of concern. Predator species, including the freshwater crocodile (Crocodylus johnstoni), are susceptible to cane toad toxins when ingested. Upstream populations of freshwater crocodiles are smaller than downstream counterparts because of limited resources. We measured the impact of cane toad arrival on densities of these upstream populations. Aims. Our aim was to determine whether the influx of cane toads had a negative impact on populations of upstream 'stunted' freshwater crocodiles. Methods. Population surveys for crocodiles were conducted in three upstream creek systems, using day-and night-based survey methods, before the arrival of cane toads in the area. These surveys were repeated under similar conditions following the arrival of cane toads, to compare the distribution and densities of freshwater crocodiles and, hence, measure the impact of cane toads. Key results. There were significant declines in crocodile density at two survey sites following the arrival of cane toads, and we found dead crocodiles and cane toad carcasses with crocodile bite marks. The third site showed no change in density. There was a decline in mean density across all sites from 3.0 crocodiles km(-1) to 1.1 crocodiles km(-1) following the arrival of cane toads. Conclusions. There was an overall decrease in crocodile densities and a reduction in distribution following the arrival of cane toads into the survey area. Dead crocodiles and evidence of their having eaten cane toads strongly suggest that these declines were caused directly by the arrival of cane toads into the area. One site showed no apparent change other than an increase in wariness, which may reflect the distribution of available feeding and shelter resources among the three sites. Implications. These results suggest that upstream freshwater crocodile populations are highly susceptible to cane toad toxins, and that impacts on their population can include local extirpation. Considering their morphological and possibly genetic distinctiveness, the loss of these unique populations is of conservation concern.

Sex-ratio bias across populations of a freshwater turtle (Testudines : Chelidae) with genotypic sex determination

Mon, 5 Feb 2018 15:36:29

Adult sex ratios vary considerably among populations of single species and across years, but the best evidence is drawn from species with temperature-dependent sex determination. It is difficult to disentangle the effects of bias in the production of the sexes and the effects of a range of other factors contributing to biased adult sex ratios. In this paper, we survey sex ratios across populations of a species constrained to produce 1:1 offspring sex ratios by genotypic sex determination and show considerable variation in adult sex ratios. Raw adult sex ratios of Emydura macquarii emmottii were significantly biased in nine of the 11 populations examined. In all but one case, the bias was strongly in favour of males. Part of the bias in sex ratio was attributed to the differing ages of maturity of males and females-males mature younger than females-which leads to more male cohorts being included in the calculations of sex ratio than female cohorts. However, correcting for this effect brought the sex ratios of the populations closer to parity, as expected, and accounted for an overall 62% of the male surplus evident in the adult sex ratio. Even so, it was insufficient to explain the strong male bias (1.2-2.9) in five of the nine populations initially showing such bias. This provides support to those who advise caution in interpreting adult sex ratio data for freshwater turtles in the context of demography, sex allocation or evaluating the impact of climate change.

Changes in the distribution and abundance of saltwater crocodiles (Crocodylus porosus) in the upstream, freshwater reaches of rivers in the Northern Territory, Australia

Mon, 5 Feb 2018 15:34:37

Since they were declared a protected species in 1971, populations of saltwater crocodiles ( Crocodylus porosus) have increased in the tidal rivers, freshwater swamps and marine waters of the Northern Territory. The recovery of the C. porosus population has been accompanied by an increase in the incidence of ` problem crocodiles' that represent a threat to people in freshwater and marine habitats. Despite the implications for human safety, little is known about C. porosus populations in the freshwater reaches of rivers, well upstream of tidal influence. In this study, we examined the density and body- size structure of C. porosus populations in three freshwater rivers using a combination of data from spotlight and helicopter surveys conducted between the 1980s and 2005, and the inland extent of C. porosus using distribution records in the Northern Territory. Since the 1980s, the density of C. porosus in upstream, freshwater reaches of the Daly and Roper rivers has increased, as has the inland extent of C. porosus on the Daly River. Although C. porosus was not detected in spotlight surveys of the Victoria River, helicopter survey and anecdotal records indicate that C. porosus was present after 1989. In all, 52.1% of the crocodiles sighted in spotlight surveys were 2.1 - 3.4 m long. Distribution records show that C. porosus occurs up to 235 km inland and at elevations of up to 126 m above sea level. The potential distribution of C. porosus is likely to be similar to that of barramundi ( Lates calcarifer), a readily identifiable diadromous fish that must spawn in estuarine waters and occurs at elevations of up to 178 m above sea level. Because the density and inland extent of C. porosus in freshwater rivers is likely to increase, it is recommended that: ( 1) programs communicating crocodile awareness use the linkage between the presence of barramundi and the potential presence of C. porosus; ( 2) that crocodile warning signs be erected in upstream areas within the potential range of C. porosus; ( 3) that research be conducted on developing techniques to detect and exclude C. porosus from swimming areas; and ( 4) that widespread systematic surveys be undertaken to document the inland extent of C. porosus.

Population parameters and life-table analysis of two coexisting freshwater turtles: are the Bellinger River turtle populations threatened?

Mon, 5 Feb 2018 15:31:53

Two species of freshwater turtle coexist in the Bellinger River: Elseya georgesi is common but limited to the Bellinger River, whereas Emydura macquarii is widespread but rare in the Bellinger River. The Bellinger River population of E. macquarii has been proposed as a distinct subspecies, so it may be endangered. Survivorship, fecundity, growth, size and age were determined for El. georgesi and the finite rate of increase (lambda) was estimated by a life-table analysis using mark - recapture data from surveys between 1988 and 2004. These parameters were compared with those of well studied populations of E. macquarii to assess whether modelling the demographic parameters of El. georgesi could serve as a surrogate for estimating the influences of these demographic parameters on. in the Bellinger River population of E. macquarii. We estimated that similar to 4500 El. georgesi inhabit the study area and, despite a size distribution strongly biased towards large individuals, the population is increasing (lambda = 1.15) in the best-case scenario, or slightly decreasing (lambda = 0.96) in the worst-case scenario. Comparing El. georgesi with E. macquarii from the Bellinger River and elsewhere suggests that E. macquarii grows faster, attains greater maximum size, has a greater clutch size and a higher fecundity than El. georgesi. Hence, El. georgesi does not serve as a good surrogate to determine demographic influences on. in E. macquarii.

Dietary ecology of the Australian freshwater turtle (Elseya sp.: Chelonia : Chelidae) in the Burnett River, Queensland

Mon, 5 Feb 2018 15:31:01

The Burnett River snapping turtle (Elseya sp.) from the Burnett, Mary and Fitzroy river systems is an undescribed Australian freshwater turtle, of which very little ecological information is known. This paper describes the dietary ecology of the species in the Burnett River catchment. Stomach and faecal samples were collected from turtles and an index of relative importance was used to rank food items found in stomach samples. This index indicated that algae and aquatic ribbon weed (Vallisneria) were the dominant food items consumed. No difference in diet was found between males and females. Although the sample size was small, diet appeared to vary slightly seasonally, with Elseya sp. selectively feeding on the flower buds of the Chinese elm tree (Celtis chinensis) and the seeds of the blackbean tree (Castanospermum australe) when these food items were seasonally available. Faecal samples suggest that the most ingested foods ( algae and aquatic ribbon weed) were also the most digestible. Although predominantly herbivorous, Elseya sp. was seen to eat carrion once in the wild.

Aggressive interactions between freshwater turtle, Chelodina oblonga, hatchlings and freshwater crayfish, Cherax spp.: implications for the conservation of the critically endangered western swamp turtle, Pseudemydura umbrina

Mon, 5 Feb 2018 15:30:00

Assessing the potential impact of invasive cane toads on a commercial freshwater fishery in tropical Australia

Mon, 5 Feb 2018 15:29:33

Context. The toxins produced by cane toads (Rhinella marina) are fatal to many Australian predators that ingest these invasive anurans. To date, the potential economic impact of the cane toad invasion has attracted little attention. Toads have recently arrived at a large impoundment (Lake Argyle) in north-eastern Western Australia, that supports a commercial fishery for silver cobbler (shovel-nosed catfish, Arius midgleyi), raising concern that the toads may inflict significant economic damage by killing fish. Aims. Our research aimed to clarify the vulnerability of silver cobblers to the eggs and larvae of cane toads by determining (a) whether catfish are adversely affected if they prey on toad eggs or tadpoles, and (b) whether surviving catfish learn to avoid cane toad eggs and tadpoles in subsequent encounters. Methods. We conducted laboratory feeding trials to examine feeding responses of catfish to cane toad eggs and tadpoles in early and late developmental stages. Fish that survived exposure to toad eggs and/or tadpoles were re-tested with potential prey of the same sizes and developmental stages four days later. Key results. Our laboratory trials confirmed that some catfish eat toad eggs and die; but most catfish avoided the eggs. Catfish readily consumed toad tadpoles at both early and late developmental stages, but without experiencing mortality; and soon learned not to consume this toxic new prey type. Conclusions and implications. Despite potential frequent episodes of mortality of small numbers of catfish during the wet season, the overall impacts of cane toads on the Lake Argyle fishery likely will be minimal.

Ecological and physiological impacts of salinisation on freshwater turtles of the lower Murray River

Mon, 5 Feb 2018 15:28:43

Context. The increasing intensity and extent of anthropogenically mediated salinisation in freshwater systems has the potential to affect freshwater species through physiological and ecological processes. Determining responses to salinisation is critical to predicting impacts on fauna. Aims. We aimed to quantify the response of wild-caught turtles from freshwater lakes that had become saline in the lower Murray River catchment. Methods. Plasma electrolytes of all three species of freshwater turtle from South Australia were compared among two freshwater sites (Horseshoe Lagoon and Swan Reach), a brackish lake (Lake Bonney) and a saline lake (Lake Alexandrina). Key results. Chelodina longicollis, C. expansa and Emydura macquarii from a brackish lake had higher concentrations of plasma sodium and chloride than those from freshwater habitats. However, osmolytes known to increase under severe osmotic stress (urea and uric acid) were not elevated in brackish sites. Turtles from the highly saline lake were colonised by an invasive marine worm which encased the carapace and inhibited limb movement. Conclusions. Freshwater turtles in brackish backwaters had little response to salinity, whereas the C. longicollis in a saline lake had a significant physiological response caused by salt and further impacts from colonisation of marine worms. Implications. Short periods of high salinity are unlikely to adversely affect freshwater turtles. However, secondary ecological processes, such as immobilisation from a marine worm may cause unexpected impacts on freshwater fauna.

A method of sampling blood from Australian freshwater turtles

Mon, 5 Feb 2018 15:28:12

Blood sampling is an essential technique in many herpetological studies. This paper describes a quick and humane technique to collect blood samples from three species of Australian chelid turtles ( Order Pleurodira): Chelodina expansa, Elseya latisternum, and Emydura macquarii signata.

Factors influencing occurrence of a freshwater turtle in an urban landscape: a resilient species?

Mon, 5 Feb 2018 14:58:44

Context Species vary broadly in their ability to adapt to urbanisation. Freshwater turtles are vulnerable to the loss and degradation of terrestrial and aquatic habitat in urban environments. There have been few publications investigating impacts of urbanisation on freshwater turtles in Australia. Aims We investigated the effects of urbanisation on the distribution and abundance of the eastern long-necked turtle (Chelodina longicollis) in greater Melbourne. Methods We examined occurrence and relative abundance of C. longicollis at 55 wetlands across an urban-rural gradient in relation to site- and landscape-level factors. Occupancy was modelled using the program PRESENCE, and incorporated landscape and habitat covariates. A negative binomial regression model was used to examine the influence of landscape and habitat factors on relative abundance by using WinBUGS. Key resultsC. longicollis occupied 85% of the 55 wetlands we surveyed, and we found no evidence that wetland occupancy was influenced by the variables we measured. However, relative abundance was highest at wetlands with low water conductivity and heavy metal pollution, and in wetlands furthest from rivers. ConclusionsC. longicollis appears to be resilient to urbanisation and is likely to persist in urban landscapes, possibly because of the creation of new wetlands in Australian cities. However, long-term studies focussed on demographic parameters, or survivorship, may elucidate as yet undetected effects of urbanisation. Although no specific management recommendations may be necessary for C. longicollis in urban areas at this time, this species may be in decline in non-urban areas as a result of climatic changes and wetland drying. Implications Our findings suggest that caution is required before drawing generalised conclusions on the impacts of urbanisation on turtles, as the effects are likely to be species-specific, dependent on specific ecology and life-history requirements. Further studies are required to ascertain these relationships for a wider array of species and over longer time spans.

Freshwater turtles of the Kikori Drainage, Papua New Guinea, with special reference to the pig-nosed turtle, Carettochelys insculpta

Mon, 5 Feb 2018 14:58:16

A survey of the Kikori River drainage of the Gulf Province of Papua New Guinea identified four species of freshwater turtle. The pig-nosed turtle Carettochelys insculpta and the southern New Guinea soft-shelled turtle Pelochelys bibroni are riverine species. The New Guinea spotted turtle Elseya novaeguineae lives primarily in the tidal freshwater creeks and streams, flooded sinkholes and swamps of the lowland rainforest. The New Guinea painted turtle Emydura subglobosa resides almost exclusively in forest sinkholes and swamps. Pelochelys bibroni was the least-common species, and is probably locally endangered. Greatest turtle diversity occurred in the Karst Plains of the Kikori sub-basin, where there is a greater diversity of habitat available to turtles. Lowest diversity occurred in the highlands, where turtles were present in very low density as introduced populations, brought in from the Kikori lowlands, Mount Bosavi and the Western Province by visiting relatives. Linguistic diversity concurred with turtle diversity of the regions in which the languages were spoken. C. insculpta nests both on riverine sand beaches and on coastal beaches, sand spits and isolated sand bars where the Kikori River discharges into the Gulf of Papua. Adult females and eggs of C. insculpta are harvested heavily by local people for local consumption.

Freshwater turtles of the TransFly region of Papua New Guinea - notes on diversity, distribution, reproduction, harvest and trade

Mon, 5 Feb 2018 14:56:57

The Chelidae is a family of side-necked turtles restricted in distribution to South America and Australasia. While their biology in Australia is reasonably well known, species in New Guinea are very poorly known despite high diversity, especially in the southern lowlands. In this paper, we report on the diversity, distribution, habitat and reproductive biology of the freshwater turtles of the TransFly region of the Western Province of Papua New Guinea, with special emphasis on reproduction of Emydura subglobosa, Elseya branderhorsti and Elseya novaeguineae. Seven species were captured, with reliable records of an eighth. A key to the freshwater turtles of the TransFly region is provided. Harvest methods, consumption, and trade in turtles by the TransFly communities are documented. There is mounting pressure to take advantage of revenue opportunities afforded by the Asian turtle trade, but this is impeded by lack of transport infrastructure. There is also insufficient demographic information on any New Guinean turtle species to make a reasoned judgment on the level of harvest that would be sustainable. Nor is there sufficient information on captive rearing for most species, and where it is available it is not accessible by local villagers. These knowledge gaps need to be addressed and factored into a management plan that is implemented before local communities can capitalise on the commercial opportunities provided by the turtle fauna without risking collapse of the resource and the implications for their concurrent subsistence economy that would follow.

Declines of freshwater turtles associated with climatic drying in Australia's Murray-Darling Basin

Mon, 5 Feb 2018 14:55:58

Context. While much attention has been paid to the effects of global temperature increases on the geographical ranges and phenologies of plants and animals, less is known about the impacts of climatically driven alteration of water regimes. Aims. To assess how three species of freshwater turtle in Australia's Murray-Darling Basin have responded to long-term decline in river flow and floodplain inundation due to climatic drying and water diversions. Methods. Turtle populations were sampled in a section of the Murray River and its floodplain in 1976-82 following a wet period and in 2009-11 at the end of the most severe drought on record. Catch per unit effort, proportional abundance in different habitat types and population structure were assessed in both periods. Key results. Catch per unit effort in baited hoop nets declined by 91% for the eastern snake-necked turtle (Chelodina longicollis) and 69% for the Murray turtle (Emydura macquarii), but did not change significantly for the broad-shelled turtle (Chelodina expansa). In addition, total catches from a range of sampling methods revealed a significantly reduced proportion of juvenile C. longicollis and E. macquarii in 2009-11, suggesting a fall in recruitment. Key conclusions. The decline of C. longicollis was likely due mainly to drought-induced loss of critical floodplain habitat in the form of temporary water bodies, and that of E. macquarii to combined effects of drought and predation on recruitment. C. expansa seems to have fared better than the other two species because it is less vulnerable to nest predation than E. macquarii and better able than C. longicollis to find adequate nutrition in the permanent waters that remain during extended drought. Implications. Declining water availability may be a widespread threat to freshwater turtles given predicted global impacts of climate change and water withdrawals on river flows. Understanding how each species uses particular habitats and how climatic and non-climatic threats interact would facilitate identification of vulnerable populations and planning of conservation actions.

Juvenile invasive red-eared slider turtles negatively impact the growth of native turtles: Implications for global freshwater turtle populations

Thu, 26 Oct 2017 14:43:38

Invasive species are a significant cause of biodiversity declines on a global scale with novel species interactions often causing ecological damage through predation or competition. Red-eared slider turtles (Trachemys scripta elegans) have been introduced to wetlands throughout the world and have negatively impacted native species, particularly other species of turtles. In our controlled feeding experiments in mesocosms juvenile red-eared slider turtles negatively impacted the growth of juvenile red-bellied turtles (Pseudemys rubriventris), an IUCN near threatened species and a Pennsylvania threatened species, through exploitative competition for limited food. In mixed species experimental treatments, in which food resources were abundant, juvenile red-bellied turtles grew significantly faster and ate more food than juvenile red-eared slider turtles. In mixed species experimental treatments, in which food resources were limited, red-eared slider turtles ingested more food, gained mass faster, and maintained body condition while red-bellied turtles lost body condition. There were significant differences in growth rates seen between resource availability regimes. In treatments in which resources were abundant there were no significant differences between turtles housed in mixed species or single species groups. In limited resource treatments red-bellied turtle body condition was significantly different between single and mixed species groups while there were significant differences in mass and body condition for red-eared slider turtles. Our results suggest that one mechanism by which red-eared slider turtles detrimentally impact ecologically similar species is through competition for limited food resources. We hypothesize that growth of red-eared slider turtle populations will lead to population declines of native turtle species throughout their introduced ranges because they use limited food resources more efficiently for their growth and development than native species. (C) 2015 Elsevier Ltd. All rights reserved.

Sea-trout habitat fragmentation affects threatened freshwater pearl mussel

Thu, 26 Oct 2017 14:43:37

Habitat fragmentation is a major reason for the decline and extinction of migratory species. Many host populations for parasites are partly migratory, consisting of both migratory and resident individuals, and we asked the question whether these two subpopulations differ in parasite susceptibility. If so, barriers intercepting migration may change the parasite encystment rate and recruitment. We used the River Ljungan, Sweden, as study system, where eight hydroelectric power plants hinder access of sea-migrating trout to most tributaries. We compared the encystment of the threatened freshwater pearl mussel (Margaritifera margaritifera) larvae on sympatric tributary-resident brown trout and sea-migrating trout (Salmo trutta) as hosts for their parasitic larvae. We also compared eighteen tributary-resident brown trout populations with the sea-migrating trout as hosts for mussel larvae. Encystment decreased faster over time on the tributary-resident trout than on the sea-migrating trout. Encystment was therefore higher on the sea-migrating trout compared to the tributary-resident trout at the time of excystment of the larvae. Growth of encysted mussel larvae was higher on the sea-migrating trout than on the tributary-resident trout. The natural density of the tributary-resident trout populations was lower than that of the sea-migrating trout in the autumn, when the mussels infest the fish, and in early summer, just before the excystment of juvenile mussels from the fish. Estimations of total numbers of encysted mussel larvae per unit stream area were higher on the sea-migrating trout than the tributary-resident trout in the autumn and in the spring at the time of juvenile mussel excystment. The higher mussel larval growth and the higher encystment on the sea-migrating trout imply that even seemingly healthy tributary mussel populations are reduced because of the habitat fragmentation. As sea-migrating trout are threatened or extinct in many rivers, fragmentation may be a large-scale problem, not only for sea-migrating populations, but also indirectly for highly threatened mussel populations. Restoration activities should primarily focus on creating free pathways for original host fish populations instead of sustaining them by supplementary stocking. (C) 2015 Elsevier Ltd. All rights reserved.

Endemic freshwater invertebrates from southern France: Diversity, distribution and conservation implications

Thu, 26 Oct 2017 14:42:05

Freshwaters ecosystems continue to face pressures from pollution, flow regime alterations, habitat destruction and exotic species invasions despite their unique biodiversity. In Europe, National Parks and Special Areas of Conservation aim to provide protection of 'aggregate' biodiversity, yet inspection of priority species lists for these sites often reveals a focus towards terrestrial species. In regions such as the Alps and the Pyrenees, this is a particularly serious problem because climate change and other anthropogenic pressures (e.g. hydropower, tourism) are causing widespread hydrological modification which is likely to drive changes in aquatic species abundance, diversity and distribution. Improved understanding of the diversity of rare plants and animals is necessary so efforts can be cost-effectively targeted to conserve the maximum number of species, whilst a clearer picture of these species' distributions is a precursor to targeting conservation efforts. This paper reports results of a study into the diversity and distribution of 17 endemic mayflies, stoneflies and caddisflies from 598 rivers sites across southern France. Endemic macroinvertebrates were found only at sites in the Pyrenees mountain range with richness peaking at 1500-1800 m above sea level. Nine of these 17 species were recorded from

Freshwater crabs and the biodiversity crisis: Importance, threats, status, and conservation challenges

Thu, 26 Oct 2017 14:42:02

Freshwater ecosystems in the tropics host a diverse endemic fauna including freshwater crabs, but the rapid loss and deterioration of habitat means that many species are now under imminent threat. Studies on freshwater fish and amphibians suggest a third to half of the species in some tropical freshwaters is either extinct or endangered, but the status of the freshwater crabs is not known. Freshwater crabs, with 1280 species, represent one-fifth of all the World's brachyurans. We therefore undertook a comprehensive IUCN Red List assessment of the freshwater crabs, which was the first time that such a study had been attempted on a global scale for any group of freshwater invertebrates. The conservation status of all known species from the Americas, Africa, Europe, Asia, and Australasia revealed unexpectedly high threat levels. Here we show that about one-sixth of all freshwater crab species have an elevated risk of extinction, only one-third are not at-risk, and although none are actually extinct, almost half are too poorly known to assess. Out of 122 countries that have populations of freshwater crabs,

Large-scale estimators of threatened freshwater catchment species relative to practical conservation management

Thu, 26 Oct 2017 14:10:51

Freshwater ecosystems are among the most threatened in the world. In light of the threats to freshwater biodiversity, it is essential to map the distribution and status of species to ascertain their threat status for prioritizing conservation action. However, while there is agreement that the conservation of freshwater ecosystems depends on whole-catchment management, there are still a wide variety of large-scale mapping methods in use, the advantages and disadvantages of which have not been fully explored. This study shows that area estimation based on minimum convex polygons should not be encouraged for aquatic species. The IUCN definition of area of occupancy (AOO) is a useful term, albeit highly scale-dependent, for assessment of the total approximate area over which a species occurs. However, for aquatic fauna, and perhaps many other organisms, assessment of occurrence should be based on the more accurate point-locality presences only. The IUCN extent of occurrence (EOO), for freshwater catchment species, should be redefined as 'the sum of the smallest hydrological units identified, of presently known, inferred or projected occurrences of a taxon, excluding cases of vagrancy, that are used to estimate the threat to a taxon'. A single hydrological unit is also the conservation or management unit. Here we suggest that this unit is the quaternary catchment. This new mapping approach is more appropriate and practical for use in both management planning and conservation action. We suggest that conservation managers and decision makers facilitate co-operation in freshwater mapping efforts by working at the same spatial scale, i.e. the same hydrological unit. (C) 2009 Elsevier Ltd. All rights reserved.

Predicting shifts in the climate space of freshwater fishes in Great Britain due to climate change

Thu, 26 Oct 2017 14:06:37

The implications of climate change for terrestrial and aquatic taxa are for their dispersal pole-wards and/or to higher altitudes as they track their climate niches. Here, bioclimatic models are developed to predict how projected climate change scenarios for a northern temperate region (Great Britain) shift the climate spaces (Le. areas of suitable thermal habitat) for 12 freshwater fishes of the Salmonidae, Percidae, Esocidae and Cyprinidae families. Climate envelope models developed in Biomod2 used the current species' distributions and their relationships with current climatic variables, and projected these onto the BCC-CSM1-1 and HadGEM2-AO climate change scenarios (low and high emissions, 2050 and 2070) in full and no dispersal scenarios. Substantial contractions in climate spaces were predicted for native salmonid fishes, with decreases of up to 78% for Atlantic salmon Salmo salar, with these largely unchanged between the dispersal scenarios. Conversely, for the majority of cyprinid fishes, expansions were predicted, including into northern regions where they are current not present biogeographically. Only under the no dispersal scenarios did their predicted distributions remain the same as their current distributions. For all non-salmonid species, the most important climate variables in the model predictions related to temperature; for salmonids, they were a combination of temperature and shifts in annual mean precipitation. As these predictions suggest that there is potential for considerable alterations to the climate spaces of freshwater fishes in Great Britain during this century then regulatory and mitigation conservation actions should be undertaken to minimise these. (C) 2016 Elsevier Ltd. All rights reserved.

Long-term trends of shorebird populations in eastern Australia and impacts of freshwater extraction

Thu, 26 Oct 2017 14:04:12

Shorebirds (Charadriiformes) and their wetland habitats are under threat worldwide. While data exist for shorebird population trends for many parts of the world, two thirds of Australia's populations have not been assessed. We report the results of a large-scale aerial shorebird survey, sampling about a third of the Australian continent over a period of 24 years (1983-2006). Migratory shorebirds have declined by 73%, Australian resident shorebirds by 81%. Of the 10 wetlands supporting the highest number of shorebirds within the survey bands, eight were inland wetlands and only two coastal, emphasising the importance of inland wetlands for shorebirds. Wetland area decreased significantly at four of the 10 main sites. Annual rainfall showed no trends (1983-2005) but water extraction was substantial for four of the 10 wetlands, contributing to reduced flooding extent and frequency. Loss of wetlands due to river regulation is a significant contributor to the drastic decline in shorebird numbers in Australia, largely unrecognized in international conservation agreements in Australia. (c) 2008 Elsevier Ltd. All rights reserved.

Preserving the evolutionary history of freshwater biota in Iberian National Parks

Thu, 26 Oct 2017 14:02:24

The establishment of protected areas is one of the main strategies to reduce losses of biodiversity. While a number of studies have evaluated the effectiveness of existing reserves in preserving representative samples of ecosystem and species diversity, there has been no systematic assessment of their effectiveness in terms of conserving evolutionary history. We used comprehensive phylogenies of four lineages of aquatic Coleoptera to investigate (i) the performance of National Parks (NPs) in representing the phylogenetic diversity (PD) of the Iberian Peninsula; (ii) the representation in NPs of the species with the highest conservation priority, as identified from a combination of their evolutionary distinctiveness and vulnerability; and (iii) whether species richness may be a good surrogate of PD when selecting new conservation areas. Our results show that Iberian NPs perform poorly in the preservation of freshwater PD. In most cases PD was not different from a random expectation, but when it did differ, PD in NPs was always lower than that obtained by a random selection of the same number of species. We also found that most of the highly evolutionarily distinct and vulnerable taxa were not covered by any NP. Finally, when additional conservation areas were selected maximizing the number of unrepresented species, the variation in PD could be very high, and as a consequence, depending on the group and the number of areas added, they could preserve much less evolutionary history than when they were specifically selected to maximize PD. (C) 2013 Elsevier Ltd. All rights reserved.

Towards standardization of studies into host relationships of freshwater mussels

Thu, 26 Oct 2017 14:02:19

Identifying species at risk from climate change: Traits predict the drought vulnerability of freshwater fishes

Thu, 26 Oct 2017 13:58:58

Trait analysis has potential to identify species that are vulnerable to climate change, but its predictive strength has not been adequately examined. Conditions during the recent 'Millennium Drought' in Australia's Murray-Darling Basin resembled the projected future climate of the region and provided an opportunity to test the ability of traits to predict population responses to a warmer and drier environment. I used data from a large-scale monitoring program to assess how 14 dietary, life-history and physiological-tolerance traits related to changes in occurrence and abundance of 39 of the basin's freshwater fish species. Species that fared worse under prolonged drought were significantly more likely to have an invertivorous rather than omnivorous diet, a low age at sexual maturity, a small maximum body size, a low spawning temperature, a long spawning season, low fecundity, demersal rather than planktonic eggs, and a low upper thermal limit. Rankings of drought vulnerability of fish species derived from correlations between population changes and traits showed good agreement with a previous assessment of inter-specific variation in resistance to drought, and were corroborated by independent observations of drought responses for some species. Trait analysis should have wide application to identifying species at risk from climate change, provided that sufficient traits are assessed and that adequate consideration is given to variation in trait-vulnerability relationships among different groups of organisms, geographic regions and types of ecosystems. (C) 2013 Elsevier Ltd. All rights reserved.

Synergistic effects of regional climate patterns and local water management on freshwater mussel communities

Thu, 26 Oct 2017 13:58:06

Human alterations to aquatic ecosystems are leading to decreases in species richness and biomass and subsequent changes in community composition. In many cases species losses are non-random: species with traits poorly adapted to the new environmental conditions suffer greater losses. We used long-term data from a southern US river, the Kiamichi River, to evaluate the synergistic effects of regional climate patterns coupled with water management practices on freshwater mussel communities. Mussel communities in the river changed over the 15 year period of this study, with overall densities and species richness decreasing and community structure shifting from assemblages dominated by thermally sensitive to thermally tolerant species. These changes corresponded with a period of very low flows in the river caused by a combination of climate patterns (a regional drought) and local water management practices (decreased reservoir releases). These low flows, coupled with high summer air temperatures, changed the river in many locations from a continuously flowing river to a series of shallow, isolated pools where water temperatures sometimes exceeded 40 degrees C. Altered conditions led to higher mortality rates of thermally sensitive compared to tolerant species. We predict future shifts in river ecosystem function as mussel communities change in response to changing climate and water management. (C) 2010 Elsevier Ltd. All rights reserved.

Freshwater conservation planning in data-poor areas: An example from a remote Amazonian basin (Madre de Dios River, Peru and Bolivia)

Thu, 26 Oct 2017 13:57:10

Using the 160,000-km(2) drainage basin of the Madre de Dios and Orthon rivers in the southwest Amazon as a test case, we piloted an approach for large-scale conservation planning for freshwater systems characterized by a near-complete lack of biological and physical data. We used newly available spatial and remote sensing datasets, including spacebome optical and radar observations, and new techniques of spatial data analysis to generate subbasin (>= 100 km(2)), stream, and floodplain and wetland habitat classifications. We then generated a preliminary plan for a network of conservation areas to protect the most intact examples of representative habitat types while maximizing longitudinal and lateral connectivity. Proposed additions for freshwater conservation complement existing reserves and build on earlier conservation planning efforts for terrestrial ecosystems. In the resulting integrated plan, at least 20% of the area of each major freshwater habitat type is represented and two continuous corridors exist from the mouth of the Madre de Dios to its headwaters in the Andes. In total, we highlighted 84 currently unprotected subbasins to fulfill our representation and connectivity goals. About two-thirds of these subbasins were considered relatively undisturbed and are identified as Level I (critical management zones) or Level II (indigenous territories), whereas one-third are potentially degraded and thus were designated as Level III (threat mitigation zones). This exercise provides an example of how newly available remote-sensing datasets and analytical tools may be used to advance freshwater conservation planning, particularly in data-poor regions. (c) 2006 Elsevier Ltd. All rights reserved.

Are rare species rare or just overlooked? Assessing the distribution of the freshwater bryozoan, Lophopus crystallinus

Thu, 26 Oct 2017 13:57:09

Given the widespread degradation of freshwater habitats, assessing the distributions of species that may be negatively or positively impacted should be of general interest. However, determining distributions of freshwater organisms that are small and patchily distributed and attached or sedentary is particularly problematic, as it is time consuming, inaccurate, and nearly impossible when the focal species is rare. Here we illustrate the use of indirect sampling approaches to survey the distribution of the rare freshwater bryozoan Lophopus crystallinus, a priority species in the UK Biodiversity Action Plan [Anonymous, 1999. UK Biodiversity Group Tranche 2 Action Plans. Invertebrates, Vol. 4. Environment Agency, Peterborough, pp. 437-439.1. By utilising two complementary methods for sampling bryozoan propagules (statoblasts), namely the collection of debris samples and sediment cores, we achieved an efficient and integrative sampling of habitats across spatial and temporal scales. Analysis of 154 debris samples, encompassing 62 rivers and lakes, identified at least 16 new populations while analysis of 26 sediment cores provided evidence of current or very recent (in the last 10-20 years) occurrence in a further six localities. These results represent a more than 10-fold increase in the current recorded distribution of the species in the UK. Logistic regression analysis provided evidence that L. crystallinus is generally found in lowland sites and is tolerant of eutrophication. Our study exemplifies how integrative and indirect sampling approaches can greatly aid in assessing the conservation status of rare aquatic species and reveals, in this case, that the focal species is less rare than previously appreciated. (c) 2006 Elsevier Ltd. All rights reserved.

Prioritizing management actions for the conservation of freshwater biodiversity under changing climate and land-cover

Thu, 26 Oct 2017 13:56:27

Freshwater ecosystems are declining under climate change and land-use change. To maximize the return on investment in freshwater conservation with limited financial resources, managers must prioritize management actions that are most cost-effective. However, little is known about what these priorities may be under the combined effects of climate and land-cover change. We present a novel decision-making framework for prioritizing conservation resources to different management actions for the conservation of freshwater biodiversity. The approach is novel in that it has the ability to model interactions, rank management options for dealing with conservation threats from climate and land-cover change, and integrate empirical data with expert knowledge. We illustrate the approach using a case study in South East Queensland (SEQ), Australia under climate change, land-cover change and their combined effects. Our results show that the explicit inclusion of multiple threats and costs results in quite different priorities than when costs and interactions are ignored. When costs are not considered, stream and riparian restoration, as a single management strategy, provides the greatest overall protection of macroinvertebrate and fish richness in rural and urban areas of SEQ in response to climate change and/or urban growth. Whereas, when costs are considered, farm/land management with stream and riparian restoration are the most cost-effective strategies for macroinvertebrate and fish conservation. Our findings support riparian restoration as the most effective adaptation strategy to climate change and urban development, but because it is expensive it may often not be the most cost-efficient strategy. Our approach allows for these decisions to be evaluated explicitly. (C) 2016 Elsevier Ltd. All rights reserved.

Traffic noise masks acoustic signals of freshwater stream fish

Thu, 26 Oct 2017 13:56:09

In order for an acoustic signal to be an effective source of communication, the signal must be successfully detected and interpreted by the intended receiver. One potential barrier to acoustic communication is background noise. Lotic systems contain a wide variety of habitats including riffles, shoals and waterfalls that can become quite noisy. The increasing prevalence of road and train crossings over small streams, and increased boat traffic in navigable rivers and lentic systems also presents potential anthropogenic noise sources with which vocal fishes did not evolve. The present study investigates the relationship between vocalizations and the natural soundscape of a common fish of the Southeastern United States, the Blacktail Shiner (Cyprinella venusta), and the potential effects anthropogenic noise from bridge crossings may have on the soundscape and acoustic communication in this species. Results revealed a particularly close association of a quiet window in the natural soundscape of C. venusta and dominant frequencies of the courtship vocalization of C. venusta. Results also indicated that C. venusta's acoustic signals propagate short distances, following predictions based on the calculated cutoff frequency of the streams they inhabit, and were masked by noise generated from bridge crossings. Our calculations suggest that road traffic noise propagates to an extent that virtually entire watersheds are impacted by this noise pollution, especially in urban areas. (C) 2015 Elsevier Ltd. All rights reserved.

Heterogeneous wetland complexes, buffer zones, and travel corridors: Landscape management for freshwater reptiles

Thu, 26 Oct 2017 13:20:14

While the importance of nearby terrestrial habitats is gaining recognition in contemporary wetland management strategies, it is rarely recognized that different wetlands are often diverse in their functions of meeting the annual or life-cycle requirements of many species, and that migration between these wetlands is also critical. Using radio-telemetry, we examined terrestrial habitat use and movements of 53 eastern long-necked turtles (Chelodina longicollis) in an area of southeast Australia characterized by spatially diverse and temporally variable wetlands. Male and female C. longicollis exhibited a high degree of dependence on terrestrial habitat, the majority (95%) of individuals using sites within 375 In of the wetland. Turtles also associated with more than one wetland, using permanent lakes during droughts and moving en masse to nearby temporary wetlands after flooding. Turtles used 2.4 +/- 0.1 (range = 1-5) wetlands separated by 427 +/- 62 (range = 401470) In and moved between these wetlands 2.6 +/- 0.3 (range = 0-12) times over the course of a year. A literature review revealed that several species of reptiles from diverse taxonomic groups move between wetlands separated by a mean minimum and maximum distance of 499-1518 m. A high proportion of studies attributed movements to seasonal migrations (55%) and periodic drought (37%). In such cases we argue that the different wetlands offer complimentary resources and that managing wetlands as isolated units, even with generous terrestrial buffer zones, would not likely conserve core habitats needed to maintain local abundance or persistence of populations over the long term. Core management units should instead reflect heterogeneous groups of wetlands together with terrestrial buffer zones and travel corridors between wetlands. (c) 2006 Elsevier Ltd. All rights reserved.

Macroinvertebrate diversity in urban and rural ponds: Implications for freshwater biodiversity conservation

Thu, 26 Oct 2017 13:19:44

Ponds are among the most biodiverse freshwater ecosystems, yet face significant threats from removal, habitat degradation and a lack of legislative protection globally. Information regarding the habitat quality and biodiversity of ponds across a range of land uses is vital for the long term conservation and management of ecological resources. In this study we examine the biodiversity and conservation value of macroinvertebrates from 91 lowland ponds across 3 land use types (35 floodplain meadow, 15 arable and 41 urban ponds). A total of 224 macroinvertebrate taxa were recorded across all ponds, with urban ponds and floodplain ponds supporting a greater richness than arable ponds at the landscape scale. However, at the alpha scale, urban ponds supported lower faunal diversity (mean: 22 taxa) than floodplain (mean: 32 taxa) or arable ponds (mean: 30 taxa). Floodplain ponds were found to support taxonomically distinct communities compared to arable and urban ponds. A total of 13 macroinvertebrate taxa with a national conservation designation were recorded across the study area and 12 ponds (11 floodplain and 1 arable pond) supported assemblages of high or very high conservation value. Pond conservation currently relies on the designation of individual ponds based on very high biodiversity or the presence of taxa with specific conservation designations. However, this site specific approach fails to acknowledge the contribution of ponds to freshwater biodiversity at the landscape scale. Ponds are highly appropriate sites outside of protected areas (urban/arable), with which the general public are already familiar, for local and landscape scale conservation of freshwater habitats. Crown Copyright (C) 2016 Published by Elsevier Ltd. All rights reserved.

Terrestrial habitat requirements of nesting freshwater turtles

Thu, 26 Oct 2017 13:18:19

Because particular life history traits affect species vulnerability to development pressures, cross-species summaries of life history traits are useful for generating management guidelines. Conservation of aquatic turtles, many members of which are regionally or globally imperiled, requires knowing the extent of upland habitat used for nesting. Therefore, we compiled distances that nests and gravid females had been observed from wetlands. Based on records of > 8000 nests and gravid female records compiled for 31 species in the United States and Canada, the distances that encompass 95% of nests vary dramatically among genera and populations, from just 8 m for Malaclemys to nearly 1400 m for Trachemys. Widths of core areas to encompass varying fractions of nesting populations (based on mean maxima across all genera) were estimated as: 50% coverage = 93 m, 75% = 154 m, 90% = 198 m, 95% = 232 m, 100% = 942 m. Approximately 6-98 m is required to encompass each consecutive 10% segment of a nesting population up to 90% coverage; thereafter, ca. 424 m is required to encompass the remaining 10%. Many genera require modest terrestrial areas (

Conservation priorities for freshwater biodiversity: The Key Biodiversity Area approach refined and tested for continental Africa

Thu, 26 Oct 2017 13:18:17

Freshwater ecosystems represent one of the most threatened broad habitat types globally. Despite containing around a third of all vertebrates, area-based approaches to conservation planning rarely include freshwater species as an explicit target for conservation. Here we describe and apply a globally applicable methodology comparable to those for other groups (i.e. Important Bird Areas) to identify river and lake catchments that represent, or contain, freshwater Key Biodiversity Areas. We discuss the rationale behind the methodology and propose appropriate definitions and quantitative threshold values for the selection criteria. Thresholds are developed through spatial analysis of species information for four comprehensively assessed freshwater taxonomic groups in continental Africa, comprising 4203 species, as recently assessed for the IUCN Red List of Threatened Species (TM). To illustrate application of the methodology freshwater Key Biodiversity Areas are identified across continental Africa, and conservation planning software used to prioritise a network of catchments that captures 99% of the total species complement within catchments covering ca. 20% of the total land area. Within these prioritised catchments only 19% of river length falls within existing Protected Areas suggesting that, given the high connectivity within freshwater ecosystems and their dependence upon catchment management for effective conservation, modification or expansion of the protected area network is required to increase effective conservation of freshwater species. By applying this methodology, gaps in the coverage of freshwater species by existing Protected Areas can be identified and used to inform conservation policy and investment to ensure it is inclusive of, and effective for, freshwater biodiversity. (C) 2012 Elsevier Ltd. All rights reserved.

Underground mining can contribute to freshwater biodiversity conservation: Allogenic succession forms suitable habitats for dragonflies

Thu, 26 Oct 2017 13:18:13

Human-induced changes negatively affect all components of freshwater ecosystems and comprise the major cause of global loss of diversity and the biotic homogenization of freshwater faunas. The high diversity of dragonflies in heavily industrialized areas is therefore paradoxical, to say the least. We compared diversity of dragonflies in three main freshwater habitat types (natural and human-made) occurring in Upper Silesia (Central Europe). We used multivariate methods and diversity indices for a general analysis, comprising both species richness and the species composition of assemblages. We recorded 50 species in mine subsidence pools from the total of 54 sampled species. These included a high proportion of habitat specialists (typically threatened species). We emphasize that secondary habitats (e.g. spontaneously originated mine subsidence pools) should not a priori be regarded as ecological traps, because these often are the available habitats with highest quality. These habitats significantly outweigh ponds in species richness and proportion of habitat specialists. The conservation potential of specific secondary habitats lies in the fact that these habitats can substitute for very rare natural wetlands often restricted to higher elevations. We assume that high diversity in this type of secondary habitats is not random, but rather that it depends on environmental heterogeneity caused by a specific allogenic succession process occurring as a direct consequence of mining. (c) 2011 Elsevier Ltd. All rights reserved.

Freshwater biodiversity under climate warming pressure: Identifying the winners and losers in temperate standing waterbodies

Thu, 26 Oct 2017 13:18:05

Climate warming is affecting the biodiversity all around the world, resulting in the expansion or contraction of the geographical range of species, and leading to colonisation (winners) and extinction (losers) events in ecosystems. It is crucial for the conservation of biodiversity to identify these potential winners and losers. We focus here on small standing waterbodies in Switzerland and on five taxonomic groups: vascular plants, snails, beetles, dragonflies and amphibians. We first assessed the sensitivity of each species to climate warming through their thermal preferences, using current altitudinal and latitudinal distribution, as a surrogate for temperature. We then evaluated the resilience of species to perturbations through five ecological and biogeographical criteria applicable to the perturbation "warming": dispersal ability, degree of habitat specialisation, geographical extent in the study area, future trend in geographical extent, and future trend of habitat availability for species. Potential winners and losers of a warming climate could be quantified through their thermal preferences. The proportion of potential losers ranged from zero species for snails to 33% of the regional species pool for dragonflies. The set of potential winners was much larger, ranging from 53% for amphibians to 61% for dragonflies. A multimetric index combining the five resilience criteria enabled the further prioritisation of the species along a gradient of extinction risk. This potential threat from climate warming is not reflected by the current Red Lists of dragonflies and amphibians, suggesting that conservation management could gain from a complementary label indicating the degree of sensitivity to warming. (C) 2011 Elsevier Ltd. All rights reserved.

Endemism and evolutionary history in conflict over Madagascar's freshwater conservation priorities

Thu, 26 Oct 2017 13:18:03

Regional-scale biodiversity indicators provide important criteria for the selection of protected areas in conservation, but their application is often hindered by a lack of taxonomic knowledge. Moreover, different indicators include different types of information, sometimes leading to divergent conservation priorities. Madagascar tops the world list of biodiversity hotspots and much conservation effort has been directed toward its threatened plants and vertebrates. In contrast, its highly diverse freshwater invertebrate fauna has received comparatively little conservation attention. We conducted an inventory of Malagasy adephagan water beetles (Coleoptera, Dytiscidae, Noteridae, Gyrinidae, Haliplidae) using a combined morphological and molecular approach. In total, 2043 beetles from 153 sites were sequenced for cytochrome oxidase subunit I (cox1), and species delimitation was carried out using the coalescent-based GMYC model. Phylogenetic relationships of the resulting entities were established using cox1 combined with partial 16S rRNA and 28S rRNA sequences. Ten national parks were assessed for their species richness, phylogenetic diversity (PD) and endemism. We were particularly interested in the contribution of endemic species to PD. Congruence between molecular and taxonomic identifications was high (91%), with 69% of sampled species endemic to Madagascar. Interestingly, we found that

Life in the suburbs: Behavior and survival of a freshwater turtle in response to drought and urbanization

Thu, 26 Oct 2017 12:01:46

Urbanization fundamentally alters the abiotic and biotic components of landscapes, presenting wildlife with serious challenges to which they must respond in order to avoid excess mortality from urban dangers. In this study, we used radio-telemetry to examine the behavior and survivorship of an Australian freshwater turtle, Chelodina longicollis, in a suburban environment compared to a control group on an adjacent nature reserve. We expected turtles in the suburbs to be less mobile, but the suburban environment did not inhibit the ability of turtles to traverse large areas and make frequent movements among several different wetlands. In fact, suburban turtles were more vagile, moving distances twice as far as those on the nature reserves. Turtles on the nature reserve responded to dropping water levels during drought by estivating for several months in sheltered woodland micro-habitats. Suburban turtles did not estivate terrestrially, in part because their water bodies experienced dampened water level fluctuations and retained water during drought, though the relative unavailability of suitable estivation sites and perceived threats could also account for their avoidance of extended forays into the terrestrial environment. Annual survival rate was 95.3% in the reserves compared to 87.6% in the suburbs, but this 7.7% decrease in survival from road mortality was not significant in our survivorship models. The continued ability of suburban turtles to remain vagile without suffering from high mortality rates is likely a product of the availability of vegetated drainage lines and under-road "box" culverts that allow turtles to travel safely throughout the suburban landscape. (C) 2009 Elsevier Ltd. All rights reserved.

Invasive cane toads (Bufo marinus) cause mass mortality of freshwater crocodiles (Crocodylus johnstoni) in tropical Australia

Thu, 26 Oct 2017 12:01:25

Invasive species are frequently blamed for faunal declines, but there is little direct evidence about the pathways, magnitude and size-selectivity of mortality induced by invaders. Top predators are of particular interest in this context, because their removal can generate substantial cascades of secondary effects on community composition. Cane toads (Bufo marinus) are large South American anurans currently spreading rapidly through tropical Australia. Native predators that attempt to consume these highly toxic toads may die as a result. During surveys of the Victoria River in the semi-arid tropical region of the Northern Territory, we documented massive mortality of freshwater crocodiles (Crocodylus johnstoni) at the toad invasion front. Dead crocodiles spanned a wide size range (0.6-2.1 m long) but with significant biases; intermediate-sized animals (0.6-1.5 m long) were more likely to be found dead. Population densities of crocodiles plummeted by as much as 77% following toad invasion, and population size-structures changed. The negative impacts of toads on crocodiles appear to be greater in these hot semi-arid landscapes than in cooler, higher rainfall areas where crocodiles have access to a wider prey base, and the toads are less prone to desiccation and can rehydrate in small, scattered water bodies rather than in the main river. Hence, the impact of cane toad invasion on this top predator may increase with increasing aridity. (C) 2008 Elsevier Ltd. All rights reserved.

Regional extinction, rediscovery and rescue of a freshwater fish from a highly modified environment: The need for rapid response

Thu, 26 Oct 2017 11:19:32

There are high rates of regional and global extinctions among freshwater species and few chances for recovery. We report here on the rediscovery after 30 years of a small fish, the southern-purple spotted gudgeon (Mogurnda adspersa), once widespread in the southern Murray-Darling Basin of south-eastern Australia. The rediscovery was in a region, the Lower Murray, where temperate riverine and wetland habitats are modified by a broad spectrum of changes including intensive flow regulation and diversions. There was some doubt whether the rediscovered population was a true remnant or a recent introduction, particularly as there was a translocated population in a nearby artificial habitat. Fortunately, a non-government organisation acted to rescue into captivity about 50 specimens as the remaining wetland habitat dried completely, soon after rediscovery, as a consequence of a decade-long drought and water diversions. We describe the habitat and ecology of fish in the rediscovery site, and provide genetic data, both nuclear (50 allozyme loci) and mtDNA (1141 base pairs; two genes), to show that they were true remnants of the regional native population. This information allows clear planning for future recovery including reintroductions, and is a case study that provides strategies, and hope, for conservation and management concerning other modified habitats. Specifically, it highlights the need for a rapid response to conserve threatened species, the recognition of remnant natural values in altered environments, and the treatment of new finds as native until there is alternate evidence. (C) 2015 Elsevier Ltd. All rights reserved.

Coarse-filter surrogates do not represent freshwater fish diversity at a regional scale in Queensland, Australia

Thu, 26 Oct 2017 11:18:18

Abiotic and biologically informed classifications are often used in conservation planning as coarse-filter surrogates for species. The relationship between these surrogates and the distribution of species is commonly assumed, but rarely assessed by planners. We derived four abiotic and eight biologically informed classifications of stream reaches to serve as surrogates for biodiversity patterns in the Wet Tropics bioregion, Queensland, Australia. We used stream reaches as planning units and, as conservation targets for each surrogate, we used two percentages - 10% and 30% - of the total stream reach length occupied by each class. We then derived minimum sets of planning units to meet targets for each surrogate and tested the effectiveness of the surrogates by calculating the average achievement of the same targets for predicted distributions of 28 fish species. Our results showed that neither abiotic nor biologically informed classifications were good at representing freshwater fish species; in fact none of the surrogates led to average representation of species better than randomly selected planning units. There were two main reasons for this poor performance. First, none of the surrogates had high classification strength or informativeness about compositional change in fish species within the study region. Second, frequency distributions of probabilities of occurrence for most fish species were strongly right-skewed, with few stream reaches having high probabilities. Combined, these results meant that selection of stream reaches to achieve surrogate targets was effectively random with respect to probabilities of fish species occurrence, leading to poor representation of fish species. We conclude there is a limited basis for using coarse-filter surrogates to represent freshwater fish diversity in this region, and that there is a clear need for research in this as well as other regions if planners are to understand the limitations associated with coarse-filter surrogates for representing freshwater biodiversity more broadly. (C) 2011 Elsevier Ltd. All rights reserved.

Species loss and shifting population structure of freshwater turtles despite habitat protection

Thu, 26 Oct 2017 11:17:17

Changes to population and community structure can have important ecological consequences and raise conservation concerns when causes are anthropogenic; however, signs of stress may not always be apparent. Turtles are long-lived and presence of adults may suggest healthy populations when lack of recruitment is actually threatening persistence. We observed and captured turtles for two years in Point Pelee National Park, Ontario, Canada, and compared our results with those collected 30 years earlier to determine if (1) species relative abundance, (2) sex ratios, and (3) age structure changed over three decades. Extirpation of the spotted turtle since 1972-1973 has altered the park's species assemblage. Evidence also suggests that Blanding's turtles have declined. Sex ratios were similar between time periods for all species except for the painted turtle which has become significantly more male-biased. Size structure for Blanding's and snapping turtles shifted towards larger and presumably older age classes. Our results suggest that limited juvenile recruitment caused the size shift. Heavy predation on turtle nests from a dense raccoon population appears to be the main factor limiting recruitment. Despite protecting a sizable fragment of turtle habitat for a century, Point Pelee has lost one species and only one other species has a large healthy population. Our study illustrates that habitat protection provides no guarantee for species persistence when multiple threats exist and highlights the necessity for monitoring populations of long-lived species. (C) 2007 Elsevier Ltd. All rights reserved.

Conservation planning for freshwater ecosystems in Mexico

Thu, 26 Oct 2017 11:16:25

Freshwater ecosystems are key to maintaining biological diversity and for human well-being. Despite their importance, these ecosystems have suffered severe transformations due to anthropogenic activity. Here we present the first priority assessment of freshwater ecosystems in Mexico at the national scale. Because species' compositional and hydrological conditions vary widely across Mexico we divided the territory into seven distinct regions in order to assign different conservation targets for biodiversity surrogates and to consider specific threats according to their impact in each region. The total conservation area network identified is equal to 30% of the country's continental surface, in which more than 94% of the biodiversity surrogates meet their established conservation targets. The regions of the Tropical Pacific and Gulf of Mexico have the largest proportions of priority sites, followed by the Central Highlands, which contains the largest number of irreplaceable sites. Tropical Pacific and the Baja California Peninsula possess the largest proportion of sites with extreme importance for conservation. Nationally, the percentage of priority sites under protection is 15.8%, of which 5.6% are sites of extreme importance, 42% are sites of high importance, and 6% are sites of medium importance for conservation. Our study highlights the importance of conducting conservation prioritization assessments at higher spatial resolution using information that is up to date and doing so in a collaborative way to strengthen decision making. This analysis helps to bridge the research-implementation gap in conservation planning to improve the representation of Mexico's freshwater biodiversity in conservation areas. (C) 2015 Elsevier Ltd. AU rights reserved.

Importance of cryptic species for identifying 'representative' units of biodiversity for freshwater conservation

Thu, 26 Oct 2017 11:14:33

Nested systems of biodiversity classification are commonly used for designating protected area networks in terrestrial and marine realms. Whilst terrestrial-style protected areas are largely inappropriate for freshwater systems, the concepts of 'representative' biodiversity and 'complementarity' can be borrowed for freshwater conservation. Cryptic species are commonly found in freshwater macroinvertebrates and fish, and most have restricted distributions relative to the described conglomerate 'species'. This indicates that 'representative' and therefore 'complementary' units of freshwater biodiversity may be smaller than previously appreciated. Using recently detected cryptic species in atyid shrimps from eastern Australia (Atyidae: Paratya australiensis, Caridina mccullochi and C. indistinca), we tested predictions about regional patterns of cryptic assemblage structure, endemism and Phylogenetic Diversity (PD) at the river scale, and discussed their implications for freshwater conservation. Patterns of distribution in these cryptic shrimp species largely corresponded with published distributional patterns of cryptic species in several freshwater fish in eastern Australia, and indicated the presence of four putative ecoregions within a previously recognised freshwater fish province (Eastern Province). However, some rivers had pronounced cryptic endemism, suggesting that rivers may not be 'representative' of one another's biodiversity even within ecoregions. PD and endemism were largely correlated with one another, as endemics typically co-occurred with widespread species at the river scale. This study indicates that cryptic species can contribute to defining patterns of biodiversity at nested spatial scales that may be important for freshwater conservation. (c) 2008 Elsevier Ltd. All rights reserved.

Ship noise and cortisol secretion in European freshwater fishes

Thu, 26 Oct 2017 11:13:56

Underwater noise pollution is a growing problem in aquatic environments and as such may be a major source of stress for fish. in the present study, we addressed the effects of ship noise and continuous Gaussian noise on adrenal activity in three European freshwater species. Underwater ship noise recorded in the Danube River and two Austrian lakes was played back to fish at levels encountered in the field (153 dB re 1 mu Pa, 30 min). Post exposure cortisol secretion was compared with control situations. Cortisol was measured with enzyme immunoassay techniques (EIA, ng cortisol/l water/g fish) in extracted aquarium water with corrections for fish mass. in the first series, two hearing specialists, the common carp (Cyprinus carpio) and the gudgeon (Gobio gobio) and one hearing generalist, the European perch (Perca fluviatilis) were exposed to ship noise. The noise level was well above hearing thresholds in these species. in a second series, fish were exposed to continuous Gaussian noise at a similar level (156 dB) which is known to induce temporary hearing loss in hearing specialists. All three species responded with increased cortisol secretion when exposed to ship noise. Interestingly, no elevation was observed when fish were exposed to continuous Gaussian noise. Our results indicate that ship noise characterized by amplitude and frequency fluctuations, constitutes a potential stressor in contrast to continuous noise. Surprisingly, the data also demonstrate no apparent differences between species possessing excellent hearing abilities (hearing specialists) and species with poor hearing abilities like perch. (c) 2005 Elsevier Ltd. All rights reserved.

The rapid return of marine-derived nutrients to a freshwater food web following dam removal

Thu, 26 Oct 2017 11:13:36

Dam removal is increasingly being recognized as a viable river restoration action. Although the main beneficiaries of restored connectivity are often migratory fish populations, little is known regarding recovery of other parts of the freshwater food web, particularly terrestrial components. We measured stable isotopes in key components to the freshwater food web: salmon, freshwater macroinvertebrates and a river specialist bird, American dipper (Cinclus mexicanus), before and after removal of the Elwha Dam, WA, USA. Less than a year after dam removal, salmon returned to the system and released marine-derived nutrients (MDN). In that same year we documented an increase in stable-nitrogen and carbon isotope ratios in American dippers. These results indicate that MDN from anadromous fish, an important nutrient subsidy that crosses the aquatic-terrestrial boundary, can return rapidly to food webs after dams are removed which is an important component of ecosystem recovery. (C) 2015 Elsevier B.V. All rights reserved.

Anthropogenic refuges for freshwater biodiversity: Their ecological characteristics and management

Thu, 26 Oct 2017 11:12:57

We reviewed literature describing the potential for freshwater anthropogenic waterbodies to act as refuges from disturbance. We identified research related to the refuge potential of a wide range of waterbodies, using waterbody names as keywords along with 'artificial' and 'freshwater'. Potential freshwater anthropogenic refuges were more often standing than running waters. Agricultural ponds, rural and urban drainage ditches and transport canals were the most diverse for all aquatic taxa, whereas irrigation infrastructure was least diverse. Comparatively little is known about the refuge role of fire dams, urban artificial ponds, golf course lakes, disused industrial ponds and retaining walls. Local-scale attributes associated with high biodiversity were: presence of macrophytes (for animals), absence of fish (for amphibians, invertebrates), natural bed materials and hydroperiod (all biota). Landscape variables associated with high biodiversity were proximity to and connectivity with other waterbodies and to natural terrestrial vegetation. Moderate levels of management intervention were also associated with higher biodiversity. Many knowledge gaps about the function of anthropogenic refuges within landscapes exist and require further research. One of the most important limitations to the provision of refuges for freshwater biodiversity by anthropogenic waterbodies is the lack of recognition of their actual or potential biodiversity value. Anthropogenic waterbodies need to be recognised for their potential to support biodiversity conservation and climate change adaptation for freshwater species, while being managed to prevent the spread of invasive species. (C) 2013 Elsevier Ltd. All rights reserved.

Uncovering an obscure trade: Threatened freshwater fishes and the aquarium pet markets

Thu, 26 Oct 2017 11:12:53

While the collection of fish for the aquarium pet trade has been flagged as a major threat to wild populations, this link is tenuous for the unregulated wild collection of endemic species because of the lack of quantitative data. In this paper, we examine the extent and magnitude of collection and trade of endemic and threatened freshwater fishes from India for the pet markets, and discuss their conservation implications. Using data on aquarium fishes exported from India, we try to understand nature of the trade in terms of species composition, volume, exit points, and importing countries. Most trade in India is carried out under a generic label of "live aquarium fish"; yet despite this fact, we extracted export data for at least thirty endemic species that are listed as threatened in the IUCN Red List. Of the 1.5 million individual threatened freshwater fish exported, the major share was contributed by three species; Botia striata (Endangered), Carinotetraodon travancoricus (Vulnerable) and the Red Lined Torpedo Barbs (a species complex primarily consisting of Puntius denisonii and Puntius chalakkudiensis, both 'Endangered'). Using the endangered Red Lined Torpedo Barbs as a case study, we demonstrate how existing local regulations on aquarium fish collections and trade are poorly enforced, and are of little conservation value. In spite of the fact that several threatened and conservation concern species are routinely exported, India has yet to frame national legislation on freshwater aquarium trade. Our analysis of the trade in wild caught freshwater fishes from two global biodiversity hotspots provides a first assessment of the trade in endangered and threatened species. We suggest that the unmanaged collections of these endemic species could be a much more severe threat to freshwater biodiversity than hitherto recognized, and present realistic options for management. (C) 2013 Elsevier Ltd. All rights reserved.

Quantifying the host relationships of endangered freshwater mussels - Unio crassus demonstrates a need for unifying methodologies

Thu, 26 Oct 2017 11:12:48

Can local ecological knowledge be used to assess status and extinction drivers in a threatened freshwater cetacean?

Thu, 26 Oct 2017 11:02:26

Local ecological knowledge constitutes a potentially useful source of information for conservation, but the quality, limitations and biases of this body of knowledge remain largely untested. The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is a highly threatened freshwater cetacean found in one of the world's most densely populated human environments. The dynamics of porpoise decline remain poorly understood, and local ecological knowledge from fishing communities across its range may represent an important conservation tool for monitoring porpoise population status and quantifying levels of human-caused mortality. We used interview data from an extensive survey of fishing communities across the middle-lower Yangtze drainage to investigate spatial and temporal patterns of porpoise abundance, mortality and population change. Interview data on porpoise relative abundance and decline, especially weekly sighting frequencies, show congruent spatial patterns with data collected from boat-based Yangtze cetacean surveys, demonstrating that informant data can provide accurate quantitative information on these two key parameters of species conservation status. Interview-based collection of local ecological knowledge therefore represents a useful monitoring method for assessing population trends in freshwater cetaceans and other charismatic or distinctive aquatic species, and may be particularly appropriate in regions where resources for regular boat-based surveys are limited. Using local ecological knowledge to identify primary threats to the porpoise population is less straightforward due to probable biases in interview data on porpoise mortality. However, interview data are able to demonstrate that the number of porpoises killed annually in the Yangtze mainstem may have doubled and that the annual mortality rate may have quadrupled over the past two decades, with mortality due to vessel strikes and other factors having increased more in recent years than by-catch mortality. It seems unlikely that fisheries mortality has been the dominant driver of porpoise decline in the Yangtze mainstem, suggesting that regulating regional fisheries may not be sufficient for porpoise conservation. (C) 2012 Elsevier Ltd. All rights reserved.

Conservation planning for connectivity across marine, freshwater, and terrestrial realms

Thu, 26 Oct 2017 11:01:43

Conservation plans are usually developed for regions that encompass only one environmental realm (terrestrial, freshwater or marine) because of logistical, institutional and political constraints. This is inadequate because these realms often interact through processes that form, utilize and maintain interfaces or connections, which are essential for the persistence of some species and ecosystem functions. We present a conceptual framework for systematic conservation prioritization that explicitly accounts for the connectivity between the terrestrial, marine, and freshwater realms. We propose a classification of this connectivity that encompasses: (1) narrow interfaces, such as riparian strips; (2) broad interfaces, such as estuaries: (3) constrained connections, such as corridors of native vegetation used by amphibians to move between natal ponds and adult habitat; and (4) diffuse connections, such as the movements of animals between breeding and feeding habitats. We use this taxonomy of inter-realm connectivity to describe existing and new spatial conservation prioritization techniques that aim to promote the persistence of processes that operate between realms. (C) 2009 Elsevier Ltd. All rights reserved.

Importance of reservoirs for the conservation of freshwater molluscs in a tropical urban landscape

Thu, 26 Oct 2017 11:00:37

Freshwater species and ecosystems are gravely imperiled, particularly within urban landscapes of tropical Asia. In one of the region's most urbanized landscapes (i.e., Singapore), we determined: (1) the importance of six different habitats (i.e., catchment reservoirs, estuarine reservoirs, forest streams, rural streams, ponds and monsoon canals) for conserving the diversity of freshwater molluscs; (2) key environmental factors (e.g., pH) affecting molluscan distribution; (3) important biogeographical determinants (e.g., area) of molluscan richness within each habitat; and (4) the habitat affinities of introduced species. High sampling saturation was achieved at most study habitats with minimal sampling effort, suggesting that the utilization of molluscs as bioindicators can expedite freshwater conservation initiatives. Estuarine reservoirs (6.0 +/- 2.0) had the highest molluscan richness, vis-a-vis catchment reservoirs, forest streams, rural streams, ponds and monsoon canals (3.0 +/- 1.5; 0; 3.3 +/- 2.0; 1.8 +/- 0.5 and 3.5 +/- 0.5 respectively). Both reservoir types possessed species compositions distinct from other habitats and contained majority (76%) of the sampled species. Reservoirs therefore serve to conserve the bulk of local freshwater malacofauna, especially if they are maintained at near-neutral pH levels (i.e., similar to 7.3) and contain large substrates (i.e., rocks). Area was the best predictor of molluscan richness across all habitats, implying that larger freshwater habitats require higher conservation priorities than smaller ones. Introduced (non-native) species (e.g., Pomacea canaliculata) had high affinities for reservoirs, which are in need of monitoring to curb population expansions. The interminable growth of human settlements urgently requires a reconciliatory approach, which includes the ecologically-sound design and management of modified habitats to complement reserves in sustaining native freshwater species. (c) 2005 Elsevier Ltd. All rights reserved.

Integrating freshwater and terrestrial priorities in conservation planning

Thu, 26 Oct 2017 10:55:27

The integration of freshwater and terrestrial biodiversity priorities in systematic conservation planning is a major challenge to conservation planners. Maintaining upstream-downstream connectivity and the influence of catchments on freshwater ecological integrity are some of the issues that make it difficult to reconcile terrestrial and freshwater conservation planning. As a result most conservation assessments are often biased towards terrestrial systems without adequate incorporation of freshwater biodiversity in determining priority areas for conservation. In this paper, we propose a protocol for integrating the assessment of freshwater and terrestrial priorities in conservation planning, based on a case study from Mpumalanga Province in South Africa. The approach involves the separate assessment of freshwater priority areas, and using the outcome to influence the selection of terrestrial priority areas. This allowed both freshwater and terrestrial biodiversity to be incorporated in conservation planning without compromising their unique requirements. To test the effectiveness of this approach, we assessed percentage overlap between freshwater and terrestrial priority areas, target achievement, and the area required to achieve targets. We then compared the outcome from the proposed approach with the separate assessments of freshwater and terrestrial biodiversity priorities, and when both systems are given an equal weighting in a single assessment. The results showed that there was a noticeable improvement in the overlap of priority areas for freshwater and terrestrial biodiversity from 23% to 47%. Target achievement for freshwater biodiversity improved by 10% when terrestrial assessment was based on freshwater priority areas as opposed to terrestrial systems being assessed alone. There was negligible increase in area required, whether there was integration of freshwater and terrestrial biodiversity or no integration. We conclude that the most efficient way to achieve integration in conservation planning is to preferentially select areas where freshwater and terrestrial biodiversity priorities overlap. (C) 2009 Elsevier Ltd. All rights reserved.

How well do protected area networks support taxonomic and functional diversity in non-target taxa? The case of Iberian freshwaters

Thu, 26 Oct 2017 10:53:56

Protected area networks represent one of the mainstays of global conservation polices and are therefore central to current efforts to maintain biodiyersity. However, a major limitation of most conservation strategies is their bias towards particular taxonomic groups and ecosystems, meaning that many taxa and habitats are often only incidentally protected as a by-product of inclusion within reserves. Here we investigate how effectively protected area networks, not specifically designated for freshwaters, support aquatic biodiversity in the Iberian Peninsula (Spain and Portugal), using data for water beetles, surrogates of overall macroinvertebrate diversity in these habitats. We explore the behaviour of different measures (alpha, beta and gamma) of both taxonomic and functional diversity at different spatial scales. Overall our findings highlight the contrasting performance of reserve systems in the maintenance of either taxonomic or functional diversity, as well as the importance of spatial scale. Iberian reserves perform relatively well in supporting taxonomic diversity of water beetles at the peninsular scale, but the same protected areas poorly represent functional diversity. Such a mismatch cautions against the use of any one diversity component as a surrogate for others, and emphasizes the importance of adopting an integrative approach to biodiversity conservation in aquatic ecosystems. Furthermore, our results often show contrasting patterns at smaller spatial scales, highlighting the need to consider the influence of scale when evaluating the effectiveness of protected area networks. (C) 2015 Elsevier Ltd. All rights reserved.

Strategic Adaptive Management in freshwater protected areas and their rivers

Thu, 26 Oct 2017 10:52:51

Aquatic ecosystems are connected over large spatial scales, have varied drivers, strong and often conflicting societal interests and interacting management processes. Many of the world's protected areas (> 100,000, similar to 42% of land) include freshwater ecosystems, some specifically declared for freshwater protection, but often supplied by rivers outside their protected boundaries. Such complex socio-ecological systems have considerable challenges. We report on Strategic Adaptive Management (SAM), a management framework that should be implemented, irrespective of resourcing. in protected areas of any river system, ranging from heavily managed or regulated through to pristine rivers. We briefly outline the four stages of the SAM process for aquatic protected areas and present three case studies from South Africa and Australia in different stages of SAM implementation. Progress is incremental, reflecting gaps, problems, and socio-ecological dynamism. Real-world implementation usually means such management is passive although experimentation with environmental flows remains possible. While maturity in SAM is incremental over years or decades, it can and should be applied even if environmental problems are urgent and contentious. The stages of SAM should produce an agreed vision and/or mission among stakeholders, with an appropriate hierarchy of objectives that determines indicators to be measured, allowing ongoing reflection, learning and adaptation. There is no panacea for achieving aquatic conservation, but Strategic Adaptive Management offers hope with its interlinked processes for navigating complexity and learning. SAM in freshwater conservation is progressing because of the imperative for sustainability, history of interaction between scientists and managers and the need for transdisciplinary governance of rivers. (C) 2010 Published by Elsevier Ltd.

Choice of capture and extraction methods affect detection of freshwater biodiversity from environmental DNA

Thu, 26 Oct 2017 10:50:38

Environmental DNA (eDNA) is used to detect biodiversity by the capture, extraction, and identification of DNA shed to the environment. However, eDNA capture and extraction protocols vary widely across studies. This use of different protocols potentially biases detection results and could significantly hinder a reliable use of eDNA to detect biodiversity. We tested whether choice of eDNA capture and extraction protocols significantly influenced biodiversity detection in aquatic systems. We sampled lake and river water, captured and extracted eDNA using six combinations of different protocols with replication, and tested for the detection of four macroinvertebrate species. Additionally, using the same lake water technical replicates, we compared the effect of capture and extraction protocols on metabarcode detections of biodiversity using 16S for eubacteria and cytochrome c oxidase I (COI) for eukaryotes. Protocol combinations for capture and extraction of eDNA significantly influenced DNA yield and number of sequences obtained from next generation sequencing. We found significantly different detection rates of species ranging from zero percent to thirty-three percent. Differences in which protocol combinations produced the highest metabarcoded biodiversity were detected and demonstrate that different protocols are required for different biodiversity targets. Our results highlight that the choice of molecular protocols used for capture and extraction of eDNA from water can strongly affect biodiversity detection. Consideration of biases caused by choice of protocols should lead to a more consistent and reliable molecular workflow for repeatable and increased detection of biodiversity in aquatic communities. (C) 2014 Elsevier Ltd. All rights reserved.

Unlocking the potential of protected areas for freshwaters

Thu, 26 Oct 2017 10:47:40

Declining trends in the integrity of freshwater systems demand exploration of all possible conservation solutions. Freshwater protected areas have received little attention, despite the prominence of protected areas as conservation interventions for terrestrial and more recently marine features. We argue that a dialogue on freshwater protected areas has been neglected both because few models of good protected area design exist, and because traditional notions of protected areas translate imperfectly to the freshwater realm. Partly as a result of this conceptual disconnect, freshwaters have been largely ignored in protected area accounting schemes, even though a number of existing freshwater conservation strategies could qualify according to general protected area definitions. Rather than impose terrestrially-motivated ideas about protected areas onto freshwaters, we propose new vocabulary -freshwater focal area, critical management zone, and catchment management zone - that can be used in conjunction with IUCN protected area categories and that recognize the special ecological dynamics of freshwaters, and in particular the critical role of fluvial processes. These terms, which attempt to diffuse concerns about locking away essential ecosystem goods and services, move us toward consideration of protected areas for freshwaters. This conceptual shift, which acknowledges that freshwater conservation may occur remotely from freshwater features, opens the door for improved integration of freshwater, terrestrial, and marine concerns in protected area design and management. (c) 2006 Elsevier Ltd. All rights reserved.

Vulnerability of European freshwater catchments to climate change

Fri, 29 Sep 2017 15:18:02

Climate change is expected to exacerbate the current threats to freshwater ecosystems, yet multifaceted studies on the potential impacts of climate change on freshwater biodiversity at scales that inform management planning are lacking. The aim of this study was to fill this void through the development of a novel framework for assessing climate change vulnerability tailored to freshwater ecosystems. The three dimensions of climate change vulnerability are as follows: (i) exposure to climate change, (ii) sensitivity to altered environmental conditions and (iii) resilience potential. Our vulnerability framework includes 1685 freshwater species of plants, fishes, molluscs, odonates, amphibians, crayfish and turtles alongside key features within and between catchments, such as topography and connectivity. Several methodologies were used to combine these dimensions across a variety of future climate change models and scenarios. The resulting indices were overlaid to assess the vulnerability of European freshwater ecosystems at the catchment scale (18 783 catchments). The Balkan Lakes Ohrid and Prespa and Mediterranean islands emerge as most vulnerable to climate change. For the 2030s, we showed a consensus among the applied methods whereby up to 573 lake and river catchments are highly vulnerable to climate change. The anthropogenic disruption of hydrological habitat connectivity by dams is the major factor reducing climate change resilience. A gap analysis demonstrated that the current European protected area network covers

Long-time effect of an invasive fish on the Odonata assemblage in a Mediterranean lake and early response after rotenone treatment

Thu, 31 Aug 2017 13:36:55

Assessment of the Odonata assemblage at the Laguna de Zóñar (a Ramsar Site in Spain) to determine the effect of a rotenone treatment that was intended to control the invasive carp at the lake. The results suggest that the treatment did not harm the Gomphidae or Libellulidae at the lake

Seed dispersal distributions resulting from landscape-dependent daily movement behaviour of a key vector species, Anas platyrhynchos

Tue, 29 Aug 2017 15:58:34

* Dispersal via animals (zoochory) is a primary mechanism for seed exchange between habitat patches. Recent studies have established that many plant species can survive waterbird gut passage. To quantify the patterns and consequences of waterbird-mediated dispersal, information on ingestion and gut passage must be combined with bird movement data. Such analysis has recently revealed seed dispersal kernels by migrating waterbirds. However, since many waterbird populations are largely resident, and migrating populations spend only a minor part of the main dispersal season (autumn–winter) on active migration, daily regional-scale movements probably cause more frequent dispersal. * We synthesized high-resolution empirical data on landscape-scale movements and seed gut passage times in a key disperser species, the mallard (Anas platyrhynchos), using a spatially explicit, mechanistic model to quantify dispersal distributions resulting from daily autumn–winter movements. We evaluated how landscape composition and seed traits affect these dispersal patterns. * The model indicates that mallards generate highly clumped seed deposition patterns, dispersing seeds primarily between core areas used for foraging and resting. Approximately 34% of all dispersed seeds are transported to communal roost areas, which may function as reservoirs for mallard-dispersed species, and 7% are transported between foraging areas. Landscape-dependent movement patterns strongly affect the dispersal distributions, resulting in multi-modal dispersal kernels, with dispersal distances increasing with fragmentation of freshwater foraging habitat. Seed size-related gut retention times determine the proportion of seeds being dispersed away from the ingestion area, with larger seeds (20 mm3) having a 8–10% higher potential for long-distance dispersal than smaller seeds (0·2 mm3), if surviving gut passage. However, twice as many small seeds will finally accomplish long-distance dispersal due to their higher gut passage survival. * Synthesis. Firstly, this study reveals how seed dispersal patterns resulting from daily waterfowl movements are shaped by landscape-dependent differences in movement patterns. Secondly, seed survival appears more important than retention time in determining the scale of long-distance dispersal by non-migrating mallards. We conclude that the frequent flights of staging waterbirds result in directed dispersal over distances inversely related to wetland availability, indicating that they maintain landscape connectivity across a range from wet to increasingly dry landscapes.

The importance of population genetic information in formulating ex situ conservation strategies for the freshwater pearl mussel (Margaritifera margaritifera L.) in Northern Ireland

Tue, 29 Aug 2017 11:31:20

Captive breeding is the last resort to protect a species that will become extinct because it is incapable of surviving in the wild without human intervention. The freshwater pearl mussel Margaritifera margaritifera is a prime candidate for such action: the species has experienced a recent range-wide decline, particularly in Europe. In Northern Ireland, M.?margaritifera is now only found in six rivers and, because of a lack of natural recruitment in the wild, it has been predicted that these populations will become extinct within 80 years. Consequently, an ex situ breeding program was established with the aim of using a semi-natural method to propagate mussels for restocking. In the present study, we analysed the levels and patterns of genetic diversity in the captive-bred mussels, as well as their parent broodstock and remnant populations from their natal and other rivers in Northern Ireland where M.?margaritifera is still found, to help develop best practice for the captive breeding program. Levels of genetic diversity were high, although there was a strong correlation between genetic diversity and census population sizes, as well as evidence of inbreeding in all populations. Small but significant levels of genetic differentiation were observed between both the captive-bred juveniles and their parent broodstock, and the samples from their source river, indicating a possible founder effect. In addition, three groups of genetically distinct clusters were observed among the remaining natural populations that could be used as the basis for defining conservation units. These findings allow us to make recommendations for efficient management of the captive breeding program, including rotation of the ex situ broodstock on a regular basis to avoid prolonged inbreeding, and the establishment of captive breeding of other populations to reflect genetic differences between putative conservation units in Northern Ireland and elsewhere.

Population genetic analysis of Arapaima gigas, one of the largest freshwater fishes of the Amazon basin: implications for its conservation

Tue, 29 Aug 2017 11:30:57

The present study reports the first population genetic analysis of Arapaima gigas, an important but critically over-exploited fish species of the Amazon basin. We sequenced two discontinuous mitochondrial DNA regions of 1204 base-pairs (bp) (NADH1 segment) and 1143 bp (ATPase segment) from 139 individuals of A. gigas representing eight localities spanning the Amazon basin from Iquitos, Peru to Macap, Brazil. We discovered 34 haplotypes separated by 44 segregating sites. The two most common haplotypes are shared among all populations and isolation-by-distance appears to be the most important population dynamic, although there is no significant association between geographical distance and genetic differentiation. Observed patterns of differentiation appear to be attributable largely to anthropogenic factors associated with over-exploitation. Greatest haplotypic diversity exists upstream of Manaus and in areas away from large centres of population. The female variance and inbreeding effective population sizes are approximately 150000 individuals and localities in the Amazon basin are connected by gene flow. Naturally low levels of population differentiation and relatively high between-population connectivity is encouraging for the conservation and management of A. gigas. If strategically placed biological reserves were created throughout the Amazon basin to act as sources of emigrants within a source-sink metapopulation model, we believe locally depleted populations can be re-populated and maintained by individuals immigrating from these reserves.

Spatial variation in egg size and egg number reflects trade-offs and bet-hedging in a freshwater fish

Fri, 25 Aug 2017 17:43:56

1. Maternal reproductive investment is thought to reflect a trade-off between offspring size and fecundity, and models generally predict that mothers inhabiting adverse environments will produce fewer, larger offspring. More recently, the importance of environmental unpredictability in influencing maternal investment has been considered, with some models predicting that mothers should adopt a diversified bet-hedging strategy whilst others a conservative bet-hedging strategy. 2. We explore spatial egg size and fecundity patterns in the freshwater fish southern pygmy perch (Nannoperca australis) that inhabits a diversity of streams along gradients of environmental quality, variability and predictability. 3. Contrary to some predictions, N. australis populations inhabiting increasingly harsh streams produced more numerous and smaller eggs. Furthermore, within-female egg size variability increased as environments became more unpredictable. 4. We argue that in harsh environments or those prone to physical disturbance, sources of mortality are size independent with offspring size having only a minor influence on offspring fitness. Instead, maternal fitness is maximized by producing many small eggs, increasing the likelihood that some offspring will disperse to permanent water. We also provide empirical support for diversified bet-hedging as an adaptive strategy when future environmental quality is uncertain and suggest egg size may be a more appropriate fitness measure in stable environments characterized by size-dependent fitness. These results likely reflect spatial patterns of adaptive plasticity and bet-hedging in response to both predictable and unpredictable environmental variance and highlight the importance of considering both trait averages and variance. 5. Reproductive life-history traits can vary predictably along environmental gradients. Human activity, such as the hydrological modification of natural flow regimes, alters the form and magnitude of these gradients, and this can have both ecological and evolutionary implications for biota adapted to now non-existent natural environmental heterogeneity.

Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish

Fri, 25 Aug 2017 17:39:55

Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body morphology can be explained by variation in migratory strategy within a species. We address this question in roach Rutilus rutilus, a partially migratory freshwater fish that migrates from lakes into streams during winter. We both compare body shape between populations that differ in migratory opportunity (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow-bodied morphology than fish from closed lakes and all-year residents. Our data suggest that a shallow body morphology is beneficial to migratory individuals and our study is one of the first to link migratory strategy and intraspecific variation in body shape.

Drivers of parasite sharing among Neotropical freshwater fishes

Fri, 25 Aug 2017 17:39:35

1. Because host-parasite interactions are so ubiquitous, it is of primary interest for ecologists to understand the factors that generate, maintain and constrain these associations. Phylogenetic comparative studies have found abundant evidence for host-switching to relatively unrelated hosts, sometimes related to diversification events, in a variety of host-parasite systems. For Monogenoidea (Platyhelminthes) parasites, it has been suggested that the co-speciation model alone cannot explain host occurrences, hence host-switching and/or non-vicariant modes of speciation should be associated with the origins and diversification of several monogenoid taxa. The factors that shape broad patterns of parasite sharing were investigated using path analysis as a way to generate hypotheses about the origins of host-parasite interactions between monogenoid gill parasites and Neotropical freshwater fishes. Parasite sharing was assessed from an interaction matrix, and explanatory variables included phylogenetic relationships, environmental preferences, biological traits and geographic distribution for each host species. Although geographic distribution of hosts and host ecology are important factors to understand host-parasite interactions, especially within host lineages that share a relatively recent evolutionary history, phylogeny had the strongest overall direct effect on parasite sharing. Phylogenetic contiguity of host communities may allow a stepping-stone' mode of host-switching, which increases parasite sharing. Our results reinforce the importance of including evolutionary history in the study of ecological associations, including emerging infectious diseases risk assessment.

Special issue: Effects of climate change of flux of nitrogen and carbon: Air-land-freshwater-marine links

Thu, 24 Aug 2017 09:19:53

Historical changes in Arctic freshwater ecosystems

Thu, 24 Aug 2017 09:19:49

Various types of ecosystem-based climate proxies have been used to assess past arctic change. Although lotic records are relatively poor because of the constant reworking of riverine material, high-quality lentic data have been assembled back to the end of the Pleistocene and deglaciation of the circumpolar Arctic. In general, climatic variations in the Holocene, partly due to changes in the shrinking effect of glacier coverage, produced significant temporal and spatial variations in arctic hydrology and freshwater ecosystems. Of particular note were the vast expansions of northern peatlands during major protracted periods of wetting. More recent lake biota and sedimentiological data reflect the general warming trend that has occurred over the last one to two centuries and indicate major changes to freshwater characteristics such as ice-cover duration and thermal stratification. Such data provide an excellent baseline against which future effects of climate change can be both projected and measured.

Effect of climate change on flux of N and C: Air-land-freshwater-marine links: Synthesis

Thu, 24 Aug 2017 09:19:19

Projected climate change might increase the deposition of nitrogen by about 10% to seminatural ecosystems in southern Norway. At Storgama, increased precipitation in the growing season increased the fluxes of total organic carbon (TOC) and total organic nitrogen (TON) in proportion to the water flux. In winter, soil temperatures near 0 degrees C, common under a snowpack, induced higher runoff of inorganic nitrogen (N) and lower runoff of TOC. By contrast, soil temperatures below freezing, caused by little snow accumulation (expected in a warmer world), reduced runoff of inorganic N, TON, and TOC. Long-term monitoring data showed that reduced snowpack can cause either decreased or increased N leaching, depending on interactions with N deposition, soil temperature regime, and winter discharge. Seasonal variation in TOC was mainly climatically controlled, whereas deposition of sulfate and nitrate (NO(3)) explained the long-term TOC increase. Upscaling to the river basin scale showed that the annual flux of NO(3) will remain unchanged in response to climate change projections.

Climate change effects on hydroecology of Arctic freshwater ecosystems

Thu, 24 Aug 2017 09:19:13

In general, the arctic freshwater-terrestrial system will warm more rapidly than the global average, particularly during the autumn and winter season. The decline or loss of many cryospheric components and a shift from a nival to an increasingly pluvial system will produce numerous physical effects on freshwater ecosystems. Of particular note will be reductions in the dominance of the spring freshet and changes in the intensity of river-ice breakup. Increased evaporation/evapotranspiration due to longer ice-free seasons, higher air/water temperatures and greater transpiring vegetation along with increase infiltration because of permafrost thaw will decrease surface water levels and coverage. Loss of ice and permafrost, increased water temperatures and vegetation shifts will alter water chemistry, the general result being an increase in lotic and lentic productivity. Changes in ice and water flow/levels will lead to regime-specific increases and decreases in habitat availability/quality across the circumpolar Arctic.

Cumulative effects of climate warming and other human activities on freshwaters of Arctic and subarctic North America

Thu, 24 Aug 2017 09:19:13

Despite their generally isolated geographic locations, the freshwaters of the north are subjected to a wide spectrum of environmental stressors. High-latitude regions are especially sensitive to the effects of recent climatic warming, which have already resulted in marked regime shifts in the biological communities of many Arctic lakes and ponds. Important drivers of these limnological changes have included changes in the amount and duration of snow and ice cover, and, for rivers and lakes in their deltas, the frequency and extent of spring floods. Other important climate-related shifts include alterations in evaporation and precipitation ratios, marked changes in the quality and quantity of lake and river water inflows due to accelerated glacier and permafrost melting, and declining percentages of precipitation that falls as snow. The depletion of stratospheric ozone over the north, together with the clarity of many Arctic lakes, renders them especially susceptible to damage from ultraviolet radiation. In addition, the long-range atmospheric transport of pollutants, coupled with the focusing effects of contaminant transport from biological vectors to some local ecosystems (e.g., salmon nursery lakes, ponds draining seabird colonies) and biomagnification in long food chains, have led to elevated concentrations of many persistent organic pollutants (e.g., insecticides, which have never been used in Arctic regions) and other pollutants (e.g., mercury). Rapid development of gas and oil pipelines, mining for diamonds and metals, increases in human populations, and the development of all-season roads, seaports, and hydroelectric dams will stress northern aquatic ecosystems. The cumulative effects of these stresses will be far more serious than those caused by changing climate alone.

An overview of effects of climate change on selected Arctic freshwater and anadromous fishes

Thu, 24 Aug 2017 09:18:41

Arctic freshwater and diadromous fish species will respond to the various effects of climate change in many ways. For wide-ranging species, many of which are key components of northern aquatic ecosystems and fisheries, there is a large range of possible responses due to inter- and intra-specific variation, differences in the effects of climate drivers within ACIA regions, and differences in drivers among regions. All this diversity, coupled with limited understanding of fish responses to climate parameters generally, permits enumeration only of a range of possible responses which are developed here for selected important fishes. Accordingly, in-depth examination is required of possible effects within species within ACIA regions, as well as comparative studies across regions. Two particularly important species (Arctic char and Atlantic salmon) are examined as case studies to provide background for such studies.

Amazonian freshwater habitats experiencing environmental and socioeconomic threats affecting subsistence fisheries

Thu, 24 Aug 2017 09:18:35

Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon's aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study's objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.

Effects of ultraviolet radiation and contaminant-related stressors on Arctic freshwater ecosystems

Thu, 24 Aug 2017 09:18:05

Climate change is likely to act as a multiple stressor, leading to cumulative and/or synergistic impacts on aquatic systems. Projected increases in temperature and corresponding alterations in precipitation regimes will enhance contaminant influxes to aquatic systems, and independently increase the susceptibility of aquatic organisms to contaminant exposure and effects. The consequences for the biota will in most cases be additive (cumulative) and multiplicative (synergistic). The overall result will be higher contaminant loads and biomagnification in aquatic ecosystems. Changes in stratospheric ozone and corresponding ultraviolet radiation regimes are also expected to produce cumulative and/or synergistic effects on aquatic ecosystem structure and function. Reduced ice cover is likely to have a much greater effect on underwater

Implications of Climate Change for Northern Canada: Freshwater, Marine, and Terrestrial Ecosystems

Thu, 24 Aug 2017 09:16:29

Climate variability and change is projected to have significant effects on the physical, chemical, and biological components of northern Canadian marine, terrestrial, and freshwater systems. As the climate continues to change, there will be consequences for biodiversity shifts and for the ranges and distribution of many species with resulting effects on availability, accessibility, and quality of resources upon which human populations rely. This will have implications for the protection and management of wildlife, fish, and fisheries resources; protected areas; and forests. The northward migration of species and the disruption and competition from invading species are already occurring and will continue to affect marine, terrestrial, and freshwater communities. Shifting environmental conditions will likely introduce new animal-transmitted diseases and redistribute some existing diseases, affecting key economic resources and some human populations. Stress on populations of iconic wildlife species, such as the polar bear, ringed seals, and whales, will continue as a result of changes in critical sea-ice habitat interactions. Where these stresses affect economically and culturally important species, they will have significant effects on people and regional economies. Further integrated, field-based monitoring and research programs, and the development of predictive models are required to allow for more detailed and comprehensive projections of change to be made, and to inform the development and implementation of appropriate adaptation, wildlife, and habitat conservation and protection strategies.

The Quadruple Squeeze: Defining the safe operating space for freshwater use to achieve a triply green revolution in the Anthropocene

Thu, 24 Aug 2017 09:15:21

Humanity has entered a new phase of sustainability challenges, the Anthropocene, in which human development has reached a scale where it affects vital planetary processes. Under the pressure from a quadruple squeeze-from population and development pressures, the anthropogenic climate crisis, the anthropogenic ecosystem crisis, and the risk of deleterious tipping points in the Earth system-the degrees of freedom for sustainable human exploitation of planet Earth are severely restrained. It is in this reality that a new green revolution in world food production needs to occur, to attain food security and human development over the coming decades. Global freshwater resources are, and will increasingly be, a fundamental limiting factor in feeding the world. Current water vulnerabilities in the regions in most need of large agricultural productivity improvements are projected to increase under the pressure from global environmental change. The sustainability challenge for world agriculture has to be set within the new global sustainability context. We present new proposed sustainability criteria for world agriculture, where world food production systems are transformed in order to allow humanity to stay within the safe operating space of planetary boundaries. In order to secure global resilience and thereby raise the chances of planet Earth to remain in the current desired state, conducive for human development on the long-term, these planetary boundaries need to be respected. This calls for a triply green revolution, which not only more than doubles food production in many regions of the world, but which also is environmentally sustainable, and invests in the untapped opportunities to use green water in rainfed agriculture as a key source of future productivity enhancement. To achieve such a global transformation of agriculture, there is a need for more innovative options for water interventions at the landscape scale, accounting for both green and blue water, as well as a new focus on cross-scale interactions, feed-backs and risks for unwanted regime shifts in the agro-ecological landscape.

Arctic Freshwater Ice and Its Climatic Role

Thu, 24 Aug 2017 09:14:06

Freshwater ice dominates the Arctic terrestrial environment and significantly impacts bio-physical and socio-economic systems. Unlike other major cryospheric components that either blanket large expanses (e.g., snow, permafrost, sea ice) or are concentrated in specific locations, lake and river ice are interwoven into the terrestrial landscape through major flow and storage networks. For instance, the headwaters of large ice-covered rivers extend well beyond the Arctic while many northern lakes owe their genesis to broader cryospheric changes. The effects of freshwater ice on climate mostly occur at the local/regional scale, with the degree of influence dependent on the magnitude, timing, location, and duration of ice cover, and the size of the water body. Freshwater-ice formation, growth, decay, and break-up are influenced by climatic variables that control surface heat fluxes, but these differ markedly between lakes and rivers. Despite the importance of freshwater ice, there has been a recent reduction in observational recordings.

Climate impacts on Arctic freshwater ecosystems and fisheries: Background, rationale and approach of the Arctic Climate Impact Assessment (ACIA)

Thu, 24 Aug 2017 09:13:04

Changes in climate and ultraviolet radiation levels in the Arctic will have far-reaching impacts, affecting aquatic species at various trophic levels, the physical and chemical environment that makes up their habitat, and the processes that act on and within freshwater ecosystems. Interactions of climatic variables, such as temperature and precipitation, with freshwater ecosystems are highly complex and can propagate through the ecosystem in ways that are difficult to project. This is partly due to a poor understanding of arctic freshwater systems and their basic interrelationships with climate and other environmental variables, and partly due to a paucity of long-term freshwater monitoring sites and integrated hydro-ecological research programs in the Arctic. The papers in this special issue are an abstraction of the analyses performed by 25 international experts and their associated networks on Arctic freshwater hydrology and related aquatic ecosystems that was initially published by the Arctic Climate Impact Assessment (ACIA) in 2005 as "Chapter 8 - Freshwater Ecosystems and Fisheries". The papers provide a broad overview of the general hydrological and ecological features of the various freshwater ecosystems in the Arctic, including descriptions of each ACIA region, followed by a review of historical changes in freshwater systems during the Holocene. This is followed by an assessment of the effects of climate change on broad-scale hydro-ecology; aquatic biota and ecosystem structure and function; and arctic fish and fisheries. Potential synergistic and cumulative effects are also discussed, as are the roles of ultraviolet radiation and contaminants. The nature and complexity of many of the effects are illustrated using case studies from around the circumpolar north, together with a discussion of important threshold responses (i.e., those that produce stepwise and/or nonlinear effects). The issue concludes with summary the key findings, a list of gaps in scientific understanding, and policy-related recommendations.

Half a century of changing mercury levels in Swedish freshwater fish

Thu, 24 Aug 2017 09:12:06

The variability of mercury (Hg) levels in Swedish freshwater fish during almost 50 years was assessed based on a compilation of 44 927 observations from 2881 waters. To obtain comparable values, individual Hg concentrations of fish from any species and of any size were normalized to correspond to a standard 1-kg pike [median: 0.69 mg kg(-1) wet weight (ww), mean +/- SD: 0.84 +/- 0.67 mg kg(-1) ww]. The EU Environmental Quality Standard of 0.02 mg kg(-1) was exceeded in all waters, while the guideline set by FAO/WHO for Hg levels in fish used for human consumption (0.5-1.0 mg kg(-1)) was exceeded in 52.5 % of Swedish waters after 2000. Different trend analysis approaches indicated an overall long-term decline of at least 20 % during 1965-2012 but trends did not follow any consistent regional pattern. During the latest decade (2003-2012), however, a spatial gradient has emerged with decreasing trends predominating in southwestern Sweden.

Declining populations of freshwater pearl mussels (Margaritifera margaritifera) are burdened with heavy metals and DDT/DDE

Thu, 24 Aug 2017 09:11:37

Many aquatic mollusks, such as the freshwater pearl mussel (Margaritifera margaritifera), are in decline throughout Europe. The reasons are largely unknown; factors that have been suggested to contribute are river bed compaction due to agricultural practices, eutrophication, or pollutants of various natures. Brittle shells of recently deceased pearl mussels from northern Bavaria with weak calcium incrustations point to the possibility that calcium metabolism is affected. It is known that certain persistent organic pollutants and some heavy metals may induce calcium deficiency in wildlife. Elevated levels of the organochlorine insecticide DD and Its metabolite DDE, as well as of cadmium and some other heavy metals, have been found in pearl mussels. Both classes of environmental pollutants are known to potentially interfere with calcium homeostasis.

Effects of climate change and UV radiation on fisheries for Arctic freshwater and anadromous species

Thu, 24 Aug 2017 09:11:33

Fisheries for arctic freshwater and diadromous fish species contribute significantly to northern economies. Climate change, and to a lesser extent increased ultraviolet radiation, effects in freshwaters will have profound effects on fisheries from three perspectives: quantity of fish available, quality of fish available, and success of the fishers. Accordingly, substantive adaptation will very likely be required to conduct fisheries sustainably in the future as these effects take hold. A shift to flexible and rapidly responsive 'adaptive management' of commercial fisheries will be necessary; local land- and resource-use patterns for subsistence fisheries will change; and, the nature, management and place for many recreational fisheries will change. Overall, given the complexity and uncertainty associated with climate change and related effects on arctic freshwaters and their biota, a much more conservative approach to all aspects of fishery management will be required to ensure ecosystems and key fished species retain sufficient resiliency and capacity to meet future changes.

Spatio-temporal trends of PCBs in the Swedish freshwater environment 1981-2012

Thu, 24 Aug 2017 09:11:19

Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and species. Perch has comparatively low PCB concentrations relative to suggested target levels, but individual congener concentrations in some lakes are concerningly high. No temporal trend is seen for CB-118 and CB-153 in perch, but significant decreasing trends exist for Arctic char and pike, for which monitoring started earlier than for perch. The lower/higher chlorinated congener ratio decreased over time in most lakes, indicating fewer new emissions. CB-118 and CB-153 concentrations in perch show spatial gradients across Sweden, with higher concentrations found near urban/industrial areas.

Assessing and managing freshwater ecosystems vulnerable to environmental change

Thu, 24 Aug 2017 09:11:18

Freshwater ecosystems are important for global biodiversity and provide essential ecosystem services. There is consensus in the scientific literature that freshwater ecosystems are vulnerable to the impacts of environmental change, which may trigger irreversible regime shifts upon which biodiversity and ecosystem services may be lost. There are profound uncertainties regarding the management and assessment of the vulnerability of freshwater ecosystems to environmental change. Quantitative approaches are needed to reduce this uncertainty. We describe available statistical and modeling approaches along with case studies that demonstrate how resilience theory can be applied to aid decision-making in natural resources management. We highlight especially how long-term monitoring efforts combined with ecological theory can provide a novel nexus between ecological impact assessment and management, and the quantification of systemic vulnerability and thus the resilience of ecosystems to environmental change.

Past, current and future Swedish freshwater monitoring from an authority perspective

Thu, 24 Aug 2017 09:11:18

Special issue - Climate change inpacts on Arctic freshwater ecosystems and fisheries

Thu, 24 Aug 2017 09:10:32

Effects of Atmospheric Nitrogen Deposition on Remote Freshwater Ecosystems

Thu, 24 Aug 2017 09:09:44

We review known and hypothesized effects of nitrogen (N) deposition owing to human activities on the chemistry, organisms, and ecosystem processes of remote oligotrophic freshwaters. Acidification is the best-known effect of N deposition on water chemistry, but additional effects include increased nutrient availability and alteration of the balance between N and other nutrients. Our synthesis of the literature, framed in a comprehensive model for the effects of N deposition on natural ecosystems, shows that all these effects can reduce biological diversity and alter ecosystem processes in remote freshwaters. N deposition is projected to grow worldwide in the near future and will interact with other global changes. Present effects on these fragile ecosystems may be only early signs of more radical impacts ahead.

General features of the Arctic relevant to climate change in freshwater ecosystems

Thu, 24 Aug 2017 09:08:59

Large variations exist in the size, abundance and biota of the two principal categories of freshwater ecosystems, lotic (flowing water; e.g., rivers, streams, deltas and estuaries) and lentic (standing water; lakes, ponds and wetlands) found across the circumpolar Arctic. Arctic climate, many components of which exhibit strong variations along latitudinal gradients, directly affects a range of physical, chemical and biological processes in these aquatic systems. Furthermore, arctic climate creates additional indirect ecological effects through the control of terrestrial hydrologic systems and processes, particularly those associated with cryospheric components such as permafrost, freshwater ice and snow accumulation/ablation. The ecological structure and function of arctic freshwater systems are also controlled by external processes and conditions, particularly. those in the headwaters of the major arctic rivers and in the adjacent marine environment. The movement of physical, chemical and biotic components through the interlinked lentic and lotic freshwater systems are major determinants of arctic freshwater ecology.

Assessing the sustainability of freshwater systems: A critical review of composite indicators

Wed, 23 Aug 2017 16:35:13

Quantitative indicators are a common means of assessing the complex dimensions of a sustainable freshwater system, and framing scientific knowledge for policy and decision makers. There is an abundance of indicators in use, but considerable variation in terms of what is being measured and how indicators are applied, making it difficult for end-users to identify suitable assessment methods. We review 95 water-related indices and analyze them along their normative, procedural, and systemic dimensions to better understand how problems are being defined, highlight overlaps and differences, and identify the context(s) in which a particular index is useful. We also analyze the intended use, end-users, and geographic scale of application for each index. We find that risk assessment is the most common application (n = 25), with indices in this group typically focusing either on hazard identification (biophysical assessments) or vulnerability of human populations. Indices that measure freshwater ecological health are not explicitly linking these indicators to ecosystem services, and in fact the concept of ecosystem services is rarely (n = 3) used for indicator selection. Resource managers are the most common group of intended end-users (n = 25), but while 28 indices involved consultation with potential end-users, 11 did not specify an intended use. We conclude that indices can be applied as solution-oriented tools, evaluating scenarios and identifying tradeoffs among services and beneficiaries, rather than only assessing and monitoring existing conditions. Finally, earlier engagement of end-users is recommended to help researchers find the right balance among indices' salience, legitimacy, and credibility and thus improve their decision relevance.

Beyond taxonomy: a review of macroinvertebrate trait-based community descriptors as tools for freshwater biomonitoring

Wed, 23 Aug 2017 15:29:11

Species traits have been frequently used in ecological studies in an attempt to develop a general ecological framework linking biological communities to habitat pressures. The trait approach offers a mechanistic alternative to traditional taxonomy-based descriptors. This review focuses on research employing traits as biomonitoring tools for freshwater ecosystems, although the lessons learned have wider application in the assessment of other ecosystem types. 2. We review the support from ecological theory to employ species traits for biomonitoring purposes (e.g. the habitat templet concept, landscape filtering hypothesis), and the subsequent studies that test the hypotheses arising from these theories, and apply this knowledge under real freshwater biomonitoring scenarios. We also include studies that deal with more specific issues such as trait trade-offs and trait syndromes. 3. We highlight the functional trait approach as one of the most promising tools emerging for biomonitoring freshwater ecosystems. Several technical issues are addressed and solutions are proposed. We discuss the need for: a broader unified trait biomonitoring tool; a more accurate understanding of the natural variation of community patterns of trait expression; approaches to diminish the effects of trait trade-offs and trait syndromes; additional life history and ecological requirement studies; and the detection of specific impacts under multiple stressor scenarios. 4. Synthesis and applications. This review provides biologists with the conceptual underpinning for the use of species traits as community descriptors and for freshwater biomonitoring and management. We expect that the functional trait approach will ultimately improve communication to managers and legislators of the importance of protecting freshwater ecosystem functions.

Catchment zoning for freshwater conservation: refining plans to enhance action on the ground

Wed, 23 Aug 2017 15:27:07

Recent advances in freshwater conservation planning allow addressing some of the specific needs of these systems. These include spatial connectivity or propagation of threats along stream networks, essential to ensure the maintenance of ecosystem processes and the biodiversity they sustain. However, these peculiarities make conservation recommendations difficult to implement as they often require considering large areas that cannot be managed under conventional conservation schemes (e.g. strict protection). To facilitate the implementation of conservation in freshwater systems, a multizoning approach with different management zones subject to different management regimes was proposed. So far, this approach has only been used in post hoc exercises where zones were allocated using expert criteria. This might undermine the cost-effectiveness of conservation recommendations, because both the allocation and extent of these zones have never been optimized using the principles of systematic planning. Here, we demonstrate how to create a catchment multizone plan by using a commonly applied tool in marine and terrestrial realms. We first test the capability of Marxan with Zones to address problems in rivers by using a simulated example and then apply the findings to a real case in the Daly River catchment, northern Australia. We also demonstrate how to address common conservation planning issues, such as accounting for threats or species-specific connectivity needs in this multizone framework, and evaluate their effects on the spatial distribution and extent of different zones. We found that by prioritizing the allocation of zones subject to different management regimes, we could minimize the total area in need of strict conservation by a twofold factor. This reduction can be further reduced (threefold) when considering species' connectivity needs. The integration of threats helped reduce the average threats of areas selected by a twofold factor.Synthesis and applications. Catchment zoning can help refine conservation recommendations and enhance cost-effectiveness by prescribing different management regimes informed by ecological needs or distribution of threats. Reliable information on these factors is a key to ensure soundness of planning. Freely available software can be used to implement the approach we demonstrate here. Catchment zoning can help refine conservation recommendations and enhance cost-effectiveness by prescribing different management regimes informed by ecological needs or distribution of threats. Reliable information on these factors is a key to ensure soundness of planning. Freely available software can be used to implement the approach we demonstrate here.

Invertebrate herbivory during the regeneration phase: experiments with a freshwater angiosperm

Wed, 23 Aug 2017 13:57:20

1 Invertebrate grazing during the regeneration phase is well known to exert a strong structuring effect in terrestrial plant communities. However, very few studies have investigated the effect of invertebrate herbivores on regenerating freshwater angiosperms, despite the obvious benefits for the development of general theories in plant community ecology. 2 Our study investigated the parameters that determine the sensitivity of the freshwater macrophyte Potamogeton pectinatus L. to herbivory by the pond snail Lymnaea stagnalis (L.). P. pectinatus was raised from winter-collected tubers in aquatic microcosms and submitted to grazing by snails at various densities and starvation levels. 3 Newly sprouted P. pectinatus was much more sensitive to snail grazing than mature plants: survival of newly sprouted plants decreased as snail density increased, whereas the survival rate of mature plants was unaffected by snail density. Moreover, the sensitivity of newly sprouted P. pectinatus to herbivory decreased as its initial tuber mass increased. The damage to newly sprouted P. pectinatus by herbivory increased with snail starvation. However, the presence of an alternative, highly palatable, food (i.e. benthic algae) deflected feeding on P. pectinatus, even by extremely hungry snails. 4 These results demonstrate the potential structuring role exerted by gastropods during the regeneration of freshwater macrophytes, supporting results from terrestrial systems. They also suggest that regenerating plants may avoid invertebrate herbivory by modulating their intrinsic characteristics (e.g. increasing propagule size) or by emerging under favourable environmental conditions (e.g. low invertebrate density, presence of alternative food). Herbivory during the regeneration phase is therefore pivotal to our understanding of plant dynamics in aquatic as well as terrestrial ecosystems, and should be integrated into explicative models of vegetation patterns across various environments.

Indirect facilitation promotes macrophyte survival and growth in freshwater ecosystems threatened by eutrophication

Wed, 23 Aug 2017 13:56:58

1. Eutrophication is a major threat for freshwater ecosystems. Submerged aquatic plants (macrophytes) can maintain clear water conditions in eutrophic lakes by competing with phytoplankton for light and nutrients. The interactions between macrophytes and phytoplankton may lead to indirect facilitation among plants and the maintenance of high macrophyte diversities in eutrophic conditions. Nonetheless, the role of indirect facilitation in promoting macrophyte-dominated clear water states under eutrophication has never been demonstrated experimentally despite important implications for these ecosystems. 2. We predicted that (i) submerged aquatic plants buffer negative consequences of eutrophication by strongly affecting biotic (phytoplankton) and environmental conditions (light, nutrients) in the water column, (ii) competition with phytoplankton results in indirect facilitation among submerged aquatic plants, and (iii) the response to indirect facilitation depends on the tolerance of submerged aquatic plants to light attenuation by phytoplankton. 3. We experimentally simulated eutrophication through fertilization and manipulated the presence of neighbouring plants in a mesocosm. By manipulating the presence of neighbours with and without fertilization, we were able to test whether competitive or facilitative interactions occur during the eutrophication of lakes. 4. Fertilization caused turbid water states by increasing phytoplankton content and light attenuation. The presence of neighbouring plants reduced phytoplankton growth and promoted survival and biomass production of macrophytes under eutrophication. 5. Synthesis. Indirect facilitation among plants can buffer the direct negative interactions between aquatic plants and phytoplankton. Indirect facilitation may prevent the decline in aquatic plant diversity of freshwater ecosystems threatened by eutrophication. Because the experimental design used here is comparable to the manipulations frequently carried out across a wide range of terrestrial ecosystems, this study may contribute to the comparison of patterns and processes in aquatic and terrestrial environments.

Greater Anis (Crotophaga major) commensal foraging with freshwater fish in the Pantanal Floodplain, Brazil

Tue, 22 Aug 2017 16:22:01

Integrating multi-scale data to model the relationship between food resources, waterbird distribution and human activities in freshwater systems: preliminary findings and potential uses

Thu, 10 Aug 2017 14:49:04

Understanding and predicting the likely consequences of anthropogenic disturbance on species and ecosystems is a major prerequisite of achieving the sustainable use of natural resources. It is also a key element in the management of sites with statutory designation. During planning and decision-making processes involving potential disturbance issues, land managers and responsible authorities are often required to take account of the needs and views of a diversity of site user groups. The effects and impacts of disturbance can occur over a range of spatial and temporal scales, and research into these consequences must address this problem. This paper provides (1) an overview of the field and analytical methodologies contributing to the development of an integrated method for collecting multi-scale bird, resource and disturbance data in freshwater systems, and (2) an overview of the drivers and need for such data in sustainable resource management. Whilst the results of the bird-habitat-disturbance modelling arising from these data will be published elsewhere, the types of information that will be generated are illustrated and their potential use within planning and decision-making processes discussed.

Marine moult migration of the freshwater Scaly-sided Merganser Mergus squamatus revealed by stable isotopes and geolocators

Thu, 29 Jun 2017 11:04:18

Scaly-sided Mergansers Mergus squamatus breed on freshwater rivers in far eastern Russia, Korea and China, wintering in similar habitats in China and Korea, but nothing was known of their moulting habitat. To investigate the moult strategies of this species, we combined wing feather stable isotope ratios (males and females) with geolocator data (nesting females) to establish major habitat types (freshwater, brackish or saltwater) used by both sexes during wing moult. Although most Scaly-sided Mergansers of both sexes probably moult on freshwater, some males and non-breeding and failed breeding females appeared to undertake moult migration to brackish and marine waters. Given the previous lack of any surveys of coastal or estuarine waters for this species during the moult period, these findings suggest important survey needs for the effective conservation of the species during the flightless moult period.

God's fishes: religion, culture and freshwater fish conservation in India

Tue, 31 Jan 2017 10:18:36

Indigenous communities worldwide have long relied on their environment for survival. Religious and customary beliefs that foster community conservation have not only bound these communities to ecosystems but also assisted in the conservation of species. We provide an example of how religion fosters the conservation of freshwater fishes in India. Since ancient times rural communities in India have revered fish species as symbols of divine power, and offered them protection in pools associated with temples. Such voluntary, informal institutions and arrangements continue to help conserve several freshwater fish species that are otherwise subjected to anthropogenic pressure in open-access areas. However, religious beliefs in India are waning as a result of increased urbanization, modernization of societies and disintegration of rural communities, and the sustainability of existing temple and community fish sanctuaries is questionable. We discuss the role of temple sanctuaries as an informal conservation strategy for freshwater fishes, and discuss the knowledge and policy gaps that need to be addressed for ensuring their future.

Catch-and-release angling as a management tool for freshwater fish conservation in India

Mon, 30 Jan 2017 12:57:53

Mahseer are popularly regarded by anglers as the king of freshwater fishes, and are valued across the Himalayan and South-east Asian regions. In India, mahseer are important game fish. Mahseer populations and their habitats face a range of anthropogenic threats, however, including unregulated fishing and habitat fragmentation as a result of hydro-development projects. Catch-and-release angling for mahseer attracts both national and international anglers and could provide information about rivers while generating revenue for regional economies. In this context, we evaluated catch-and-release angling records from rivers that flow within two Indian reserves (the Ramganga and Jia Bharali Rivers in Corbett and Nameri Tiger Reserves, respectively). Golden mahseer Tor putitora in the Ramganga and golden and chocolate mahseer Neolissochilus hexagonolepis in the Jia Bharali were the most frequently caught fish species. Catch data suggested these game fish populations are probably not negatively affected by angling activities. Interviews with stakeholders highlighted support for catch-and-release angling, mainly because of its perceived economic benefits. The data obtained in this research could potentially assist with both fish conservation and the protection of associated aquatic ecosystems.

Spatial and temporal patterns of modern (similar to 100 yr) sedimentation in a tidal freshwater marsh: Implications for future sustainability

Mon, 30 Jan 2017 12:05:33

To maintain their position within the tidal frame, tidal marshes must accrete upward at approximately the same rate as relative sea-level rise (RSLR), typically accomplished through accumulation of mineral (from fluvial, estuarine, and/or coastal waters) and/or organic (plant-derived) sediments. However, accelerating RSLR and declining fluvial suspended-sediment supplies, along with other direct anthropogenic disturbances, may limit the ability of many marshes to keep pace. This study tests hypotheses addressing the relationship of marsh surface elevation and channel influence to marsh accretion and evaluating marsh response to historic mining disturbance and long-term environmental change, using Dyke Marsh Preserve, a tidal freshwater marsh located along the Potomac River estuary (Chesapeake Bay watershed) as a model system. Variability in sediment characteristics (grain size, organic content, bulk density) and decadal-scale accretion rates (using Pb-210) across the marsh platform is related to ecogeomorphic setting, anthropogenic activities (mining), and long-term changes in river sediment supply and RSLR. In general, sediment on river/tidal-channel banks accumulates faster and is more influenced by fluvially derived sediment than in the marsh interior. Accumulation rates on the banks can be predicted using proxies for sediment supply and availability most of the time; however, these relationships do not hold for the marsh interior, highlighting the role of sediment redistribution and/or complex sediment-vegetation interactions. Development of temporally variable sediment rating curves reveals that suspended-sediment loads of the Potomac River have decreased since the late 1970s, although current loads appear adequate to support accretion on the marsh platform, if net onshore sediment-transport mechanisms exist.

Conservation challenges and action for the Critically Endangered Singapore freshwater crab Johora singaporensis

Mon, 30 Jan 2017 10:20:41

The Singapore freshwater crab Johora singaporensis is known only from three streams in Singapore and is among the top 100 most threatened species in the world. It is the only member of the genus Johora, endemic to the Malay Peninsula, to be categorized as Critically Endangered on the IUCN Red List. Extensive surveys conducted over 1 year to determine the extent of the species' distribution revealed that the population has declined significantly at its type locality in Bukit Timah Nature Reserve, Singapore Island's oldest protected forest area. The species remains extant in two unprotected streams in Bukit Batok and Bukit Gombak, which are located outside the nature reserve. Acidification of streams as a result of acid precipitation may be a factor in the decline of the species. If so, this will be the first documented instance of a species being affected negatively by anthropogenic acidification of a tropical freshwater system. The occurrence of this threatened species in a protected area has not, therefore, guaranteed its survival. There is a need for long-term and continuous monitoring of species of high conservation value, together with other measures that focus on habitat protection. Conservation efforts by the National Parks Board of Singapore in collaboration with other government agencies are ongoing in an effort to ensure the survival of this important species.

Nordic Journal of Freshwater Research

Thu, 24 Nov 2016 09:37:44

Journal of Freshwater Ecology

Thu, 24 Nov 2016 09:37:37

Ichthyological Exploration of Freshwaters

Thu, 24 Nov 2016 09:37:34

Freshwater Biological Association Annual Report

Thu, 24 Nov 2016 09:37:31

Freshwater Forum

Thu, 24 Nov 2016 09:37:31

Freshwater Laboratory Biennial Review

Thu, 24 Nov 2016 09:37:31

Aquatic Conservation

Thu, 24 Nov 2016 09:37:17

Marine and Freshwater Research

Wed, 9 Nov 2016 14:05:02

Freshwater Biology

Fri, 14 Oct 2016 14:38:41

Ecology of Freshwater Fish

Fri, 7 Oct 2016 16:49:59