Pelagic underyearling communities in a canyon-shaped reservoir in late summer

0328078 - BC 2010 RIV IT eng J - Journal Article
Jůza, Tomáš - Vašek, Mojmír - Kubečka, Jan - Seďa, Jaromír - Matěna, Josef - Prchalová, Marie - Peterka, Jiří - Říha, Milan - Jarolím, Oldřich - Tušer, Michal - Kratochvíl, Michal - Čech, Martin - Draštík, Vladislav - Frouzová, Jaroslava - Hohausová, Eva - Žaloudík, Jiří
Pelagic underyearling communities in a canyon-shaped reservoir in late summer.
Journal of Limnology. Roč. 68, č. 2 (2009), s. 304-314. ISSN 1129-5767. E-ISSN 1723-8633
R&D Projects: GA AV ČR(CZ) 1QS600170504; GA ČR(CZ) GA206/07/1392; GA ČR(CZ) GA206/06/1371; GA ČR(CZ) GP206/06/P418
Institutional research plan: CEZ:AV0Z60170517
Keywords : fry community * spatial distribution * fry trawling * environmental factors * reservoir morphology
Subject RIV: DA - Hydrology ; Limnology
Impact factor: 0.932, year: 2009

The community of pelagic fish fry present during late summer was studied in the canyon-shaped and eutrophic Římov Reservoir, using nighttime trawling over seven years. A pronounced spatial gradient in the distribution of fry was observed in the reservoir in all years, with the highest densities in the upstream area and the lowest densities near the dam. Occurrence of cyprinids was highest in the upper area, while percid fry were distributed more regularly throughout the horizontal gradient from the lower to upper areas of the reservoir. Vertically, the cyprinids were confined almost entirely to the near-surface water layer, whereas the percids dominated in the deeper strata (3-6 m depth) in all years investigated. Catches in the deepest layer sampled (between 6 and 9 meters) were only sporadic. The longitudinal gradient of fry density seems to be a result of reservoir morphology (a gradient of the relative volume of the littoral) rather than other limiting biotic or abiotic factors.
Permanent Link: http://hdl.handle.net/11104/0174478