The influence of diel period on fish assemblage in the unstructured littoral of reservoirs

Milan Říha, Jan Kubečka, Marie Prchalová, Tomáš Mrkvička, Martin Čech, Vladislav Draštík, Jaroslava Frouzová, Eva Hohausová, Tomáš Jůza, Michal Kratochvíl, Jiří Peterka, Michal Tušer, Mojmír Vašek
Fisheries Management and Ecology, 2011, 18(4): 339-347
DOI: 10.1111/j.1365-2400.2011.00790.x
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Diel changes in littoral fish assemblage were studied in four reservoirs in the Czech Republic (Central Europe). The sampling was performed by beach seining in an unstructured littoral zone. Perch, Perca fluviatilis L., roach, Rutilus rutilus (L.), bream, Abramis brama (L.), carp, Cyprinus carpio L., ruffe, Gymnocephalus cernua (L.), pikeperch, Sander lucioperca (L.), eel, Anguilla anguilla (L.) and A. brama × R. rutilus hybrids exhibited higher densities at night. Only bleak, Alburnus alburnus (L.) exhibited higher densities during the day. The number of species was higher in night hauls, and mean body size of roach and bleak was also higher at night. Diel changes in fish densities resulted in the change in species composition between day and night. The study has implication for the sampling design to assess littoral fish assemblages using beach seine netting and recommends night sampling for a representative assessment or sampling during both diel periods for a robust assessment.

Keywords: beach seining; diel migration; Římov Reservoir; sampling; species composition