Etudes sur la structure des populations de poissons, leurs interactions trophiques et leur gestion dans le lac d'Annecy

The thesis focuses on different aspects of management and ecology of commercially important fish species in Lake Annecy: an oligotrophic lake situated in Rhône-Alpes region of France. The main objectives of the study were to evaluate the fisheries data, growth of whitefish and Arctic char in Lake Annecy, study the trophic interactions in food web and to propose a trophic model for the lake using Ecopath with Ecosim (EwE) software using data collected mostly during the last 10 years from commercial and recreational fisheries monitoring . Fish monitoring data was found to be effective for management purpose. Growth of whitefish was found to be fluctuating during last 20 years. Food resources appeared to be partitioned among the Lake Annecy fish community during summer possibly limiting competitive interactions. The results from Lake Annecy trophic analysis including showed that fishery in Lake Annecy is sustainable at the present exploitation rate. Few conclusions were proposed for the fisheries management based on the results.CHAMBERY -BU Bourget (730512101) / SudocSudocFranceF