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Species composition along the vertical gradietn in canyon-shaped reservoirs
Prchalová, Marie ; Kubečka, Jan
During years 2004 and 2005, vertical gradients of fish distribution within two canyon-shaped Czech water supply reservoirs (Římov, Švihov) were examined by Nordic multimesh gillnets in both pelagic and benthic habitats. In the open water, most fish were found in the upper 5 m of depth. Below this depth nearly no fish occurred. The community was represented mainly by bleak. Towards deeper parts the portion of perch increased. In benthic areas, most fish were in the upper 3 m of depth. Abundance declined to 10 m and below this depth nearly no fish were present. Perch and roach dominated the littoral community. Ruffe preferred the deeper habitats. With respect to biomanipulative removal catches, it is sufficient to fish in the upper 5 m of the open water and in the upper 3 m in the littoral of the reservoir. For getting a rough but adequate assessment of fish community, it is satisfactory to sample the upper 5 m of the open water and the upper 10 m in the benthic part of the reservoir.
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Complex assessment of the fish assemblage of the Želivka reservoir, the biggest water supply reservoir in the ČR, in years 2004 and 2005
Prchalová, Marie ; Kubečka, Jan ; Jůza, Tomáš ; Říha, Milan ; Jarolím, Oldřich ; Tušer, Michal ; Peterka, Jiří ; Vašek, Mojmír
In the summer 2004 and 2005, the complex assessment of the fish assemblage of the Želivka reservoir (1432 ha) was carried out by gillnetting, adult and fry seining, adult and fry pelagic trawls and hydroacoustic sampling. Detailed picture of the fish assemblage was composed from every fishing gear from every depth strata of the open water as well as from the littoral zone. During two-years survey, 40.168 fish of 19 species and one hybrid were captured. The fish assemblage was dominated by cyprinid species in both years – bleak prevailed in the open water together with roach and bream; perch was abundant in the littoral zone. The assemblage of the Želivka reservoir was found to be in the stable cyprinid phase. The average abundance was 1.700 ind/ha and average biomass was 110 kg/ha. In the fish spatial distribution, the general gradients could be found – higher abundance and number of species in the tributary area and in the epilimnion and littoral.
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Long-term monitoring of the populations of Eudontomyzon mariae in the Račí potok brook (1998-2006)
Hanel, L. ; Lusk, Stanislav
The occurrence of the Ukrainian lamprey (Eudontomyzon mariae) in the Račí potok Brook is the only known population of this lamprey in the Czech republic. The status of the locality and population numbers of this species was followed up in 1998 through 2006. It is evident that the population size (as shown by the results of electro-fishings using invariably the same technique) is slightly increasing. Compared to 16 larvae.ha-1 in 1998, their number increased to 327 larvae.ha-1 in 2006. The abundance data were converted to the bottom surface, not only to that of suitable fine sediment deposits. In 2006, the same stream section was experimentally fished twice, and it has appeared that additional larvae were present in the second run (the increase in abundance being ca 38 %). In our opinion, the gradual increase in the population size of the Ukrainian lamprey in the Račí potok Brook is due to the recent revitalisation modifications of the brook bed.
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Fish assemblage and stone loach (Barbatula barbatula) population in the river Haná
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan ; Koubková, B. ; Gelnar, M.
Ecological parameters of the fish assemblage and stone loach population are presented. In total, 25 fish species from 7 families in the river Haná (23 species), including its sources Velká Haná (5 species) and Malá Haná (7 species), were found. Index of species diversity (H') ranged from 0.00 to 1.96, abundance was 89.0 - 22754.8 (mean = 3874.5) exx.ha-1 and biomass was 1.87 - 599.1 (mean = 115.07) kg.ha-1. In five localities in middle and lower parts of the Haná of total 20 localities, no fish was found. Stone loach occured in the whole longitudinal profile within the trout and cyprinid assemblages in abundance of 12.7 - 18260.7 (mean = 2452.8) exx.ha-1 and in biomass of 0.04 - 58.8 (mean = 10.27) kg.ha-1. Species weight dominance (D) was 0.31 - 15.00% (mean = 4.96%). Population of stone loach is a suitable in the stream for investigations of the fish metazoan parasite biology and ecology.
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Fish fauna of artificial wetland within the Chomoutovské jezero nature reserve, PLA Litovelské Pomoraví
Horák, Václav ; Lusk, Stanislav ; Lusková, Věra ; Halačka, Karel ; Mendel, Jan
The Chomoutov wetland was inhabited naturaly during extreme flood in 1997. During the research period, 2001-2003, 15 fish species were found in total. Most numerous within the fish community were populations of the species Rutilus rutilus, Scardinius erythropthalmus, Carassius auratus and Perca fluviatilis.
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