Diel vertical and horizontal distribution of crustacean zooplankton and young of the year fish in a sub-alpine lake: an approach based on high frequency sampling |
| |
Authors: | Masson Stephane; Angeli Nadine; Guillard Jean; Pinel-Alloul Bernadette |
| |
Affiliation: | 1 Groupe De Recherche Interuniversitaire En Limnologie Et En Environnement Aquatique (G.R.I.L.), Département De Sciences Biologiques, Université De Montréal, C.P. 6128, Succursale Centre-Ville, Montréal (québec), Canada, H3c-3j7;
2 Institut National De La Recherche Agronomique (inra), Station D'hydrobiologie Lacustre, B.P. 511, 75 Avenue De Corzent, 74203 Thonon Cedex, France |
| |
Abstract: | Understanding the spatial dynamics of predators and their preyis one of the most important goals in aquatic ecology. We studiedspatial and temporal onshoreoffshore distribution patternsin young of the year (YOY) Eurasian perch (Perca fluviatilis)and crustacean zooplankton (Daphnia hyalina, Cyclops prealpinus)along a transect in Lake Annecy (France). Our study representsa first attempt at coupling hydroacoustic fish survey and highfrequency zooplankton recording to assess simultaneously thelarge-scale distribution patterns of YOY fish and their zooplanktonprey over a diel cycle (day, dusk and night sampling). We hypothesizedthat the spatial distribution of zooplankton could be shapedby both anti-predator behaviour (horizontal and vertical migrations)and predation losses. Fish biomass, size structure and dietwere assessed from split-beam echosounding and net trawlingsamples, whereas crustacean abundances were estimated with asmall modified LonghurstHardy continuous plankton recorder.We evaluated the diel changes in the spatial distribution patternsof fish and zooplankton and determined the overlap between theirdistributions. Fish biomass was dominated by YOY perch in upperwarmer layers and salmonids (Coregonus lavaretus and Salvelinusalpinus) in the colder and oxygenated deep layers. YOY perchwere aggregated in dense schools in the epilimnion during theday and dispersed at night. Fish biomass was distributed alonga strong increasing onshoreoffshore gradient at night,whereas crustacean prey showed a decreasing gradient. This onshoreoffshorenegative gradient in crustacean distribution, expressed on ashorter scale during the day, shifted toward the surface watersat night. A distinct kinetic of diel vertical migration (DVM)patterns was exhibited by daphnid and cyclopoid populationsand resulted in distinct vulnerability to perch predation. Spatio-temporaldistribution of crustaceans in Lake Annecy during the diel cyclestudy was probably shaped both by predation loss to YOY perchand by anti-predator behaviour (DVM, DHM) by zooplankton. Theimplications for fine-scale studies of fish-zooplankton interactionsare discussed. |
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|