Winter diet of great cormorant (Phalacrocorax carbo) on the River Vltava: estimate of size and species composition and potential for fish stock losses

0360692 - BC 2012 RIV CZ eng J - Journal Article
Čech, Martin - Vejřík, Lukáš
Winter diet of great cormorant (Phalacrocorax carbo) on the River Vltava: estimate of size and species composition and potential for fish stock losses.
Folia zoologica. Roč. 60, č. 2 (2011), 129–142. ISSN 0139-7893. E-ISSN 1573-1189.
[Czech Ichthyological Conference /XII./. Vodňany, 19.05.2010-20.05.2010]
R&D Projects: GA ČR(CZ) GA206/06/1371; GA ČR(CZ) GP206/09/P266; GA AV ČR(CZ) 1QS600170504
Institutional research plan: CEZ:AV0Z60170517
Keywords : diagnostic bones * fish withdrawal * regurgitated pellets * European chub * European perch * grayling * roach * ruffe * Slapy Reservoir * trout spp.
Subject RIV: EG - Zoology
Impact factor: 0.554, year: 2011

The winter diet of the great cormorant was studied in three sites on the River Vltava in Vyšší Brod, in Prague and at Slapy Reservoir, Czech Republic. At all three sites, roach (Rutilus rutilus), bream (Abramis brama), bleak (Alburnus alburnus), European chub (Squalius cephalus), European perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) made up at least 74.2 % of the cormorants’ diet. A great potential for fish stock losses was identified for the River Vltava at Vyšší Brod and in Prague where the loss of fish due to overwintering great cormorants was estimated to be 22 kg ha–1 and up to 79 kg ha–1 respectively, i.e. belonging among the highest ever published figures for fish withdrawal caused by great cormorants from any inland waters (carp fishponds excluded). Most probably, both great cormorants and anglers are responsible for the decrease in catches of brown trout (Salmo trutta m. fario) and grayling (Thymallus thymallus) from the River Vltava in Vyšší Brod.
Permanent Link: http://hdl.handle.net/11104/0198183