Cyprinid predation on zooplankton along the longitudinal profile of a canyon-shaped reservoir

0150525 - HBU-Z 20033012 RIV DE eng J - Journal Article
Vašek, Mojmír - Kubečka, Jan - Seďa, Jaromír
Cyprinid predation on zooplankton along the longitudinal profile of a canyon-shaped reservoir.
Archiv für Hydrobiologie. Roč. 156, č. 4 (2003), s. 535-550. ISSN 0003-9136
R&D Projects: GA AV ČR IAA6017201; GA ČR GA206/02/0520
Grant - others:GA FRVŠ(CZ) 346/2000
Institutional research plan: CEZ:AV0Z6017912
Keywords : fish predation * spatial heterogeneity * zooplankton
Subject RIV: EH - Ecology, Behaviour
Impact factor: 1.261, year: 2003

In the elongated Římov Reservoir, the diet composition of the three cyprinid species, as well as the fish and zooplankton distribution, were investigated at three sites along the longitudinal transect and during two months. The studied fish were roach (Rutilus rutilus), bream (Abramis brama) and bleak (Alburnus alburnus). Their diets along the entire longitudinal transect constituted almost exclusively crustacean zooplankton. Zooplankton density declined gradually downstream in the reservoir. A relatively higher total fish catch per unit effort was found at the upstream end and a decreasing size of Daphnia in zooplankton was observed towards upstream. Such results indicated stronger fish predation pressure in the upstream part of the reservoir during growing season. Moreover, lower diet overlaps within the cyprinid assemblage at the upstream end than within the cyprinid assemblages at the downstream locations suggested intense competition for food at the upstream end of the reservoir.
Permanent Link: http://hdl.handle.net/11104/0048057