La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Food Web Structure and Trophic Control in Central Puget Sound
Auteurs :	Chris J. Harvey, Auteur ; Gregory D. Williams, Auteur ; Phillip S. Levin, Auteur
Type de document :	Article
Dans :	Estuaries and Coasts (35(3) MAY 2012)
Article en page(s) :	821-838
Résumé :	We developed a food web model of central Puget Sound to provide science-based support for ecosystem-based management and to refine our understanding of bottom-up and top-down trophic forcing. Phytoplankton accounted for a large fraction of total biomass, total throughput, and caused considerable bottom-up effects in most functional groups in a dynamic simulation fit to time series data from 1981 to 2000. Top-down control was most apparent in the case of bald eagles (Haliaeetus leucocephalus), which exhibited keystone tendencies and appeared capable of causing trophic cascades. Increasing top-down control in several predator-prey relationships improved model fits to time series data from 1981 to 2000, but not as much as introducing non-equilibrium dynamics (biomass accumulation terms) to several key vertebrates. Fishing had little effect on system dynamics. Our model appears well-suited for addressing strategic, scenario-based questions of how the community as a whole will respond to management actions.

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