| Titre : | Seasonal freshening of NW Mediterranean surface water impacts microbial heterotrophic activity and dissolved organic matter (2019) |
| Auteurs : | Maria-Lorena Gonzalez, Auteur ; Stéphane Blain, Auteur ; Ingrid Obernosterer, Auteur |
| Type de document : | Article |
| Dans : | Estuarine, Coastal and Shelf Science (230 December, 2019) |
| Article en page(s) : | 106448 |
| Langues: | Anglais |
| Mots-clés : | France ; Rhône ; Mer Méditerranée ; eau douce ; Matière organique ; Salinité |
| Mots-clés: | Dissolved organic matter ; Low salinity waters ; Microbial heterotrophic activity ; NW Mediterranean Sea |
| Résumé : | 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. |
| En ligne : | https://hal.archives-ouvertes.fr/hal-02383544/file/Gonzalez_ECSS_2019.pdf |



