Details

Autor(en) / Beteiligte

• GUILLARD, J.
• PERGA, M. E.
• COLON, M.
• ANGELI, N.

Titel

Hydroacoustic assessment of young-of-year perch, Perca fluviatilis, population dynamics in an oligotrophic lake (Lake Annecy, France)

Ist Teil von

• Fisheries management and ecology, 2006-10, Vol.13 (5), p.319-327

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2006

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• A cohort of perch, Perca fluviatilis (L.) was monitored from hatching to first winter in the oligotrophic Lake Annecy, France, by combining hydroacoustic and direct capture methods (fish plankton net and pelagic trawl). The total stock of pelagic fish increased by a factor of 10 during the season, reaching a maximum in August and decreasing in autumn. Juvenile perch were mainly pelagic, being aggregated into schools in the daytime and dispersed at night. Migration of young‐of‐year (Y‐O‐Y) perch to the pelagic zone of Lake Annecy in late spring did not significantly affect zooplankton population abundance. It did, however, result in changes in zooplankton vertical distribution, with Daphnia remaining deeper in the water column. The increase in Y‐O‐Y biomass during summer was possibly associated with collapse of the Daphnia population by late July, and copepods one month later.