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Ellimination of unwanted fish species from dam reservoirs - Possibilities, efficiency and economic evaluation.
Jůza, Tomáš ; Blabolil, Petr ; Čech, Martin ; Draštík, Vladislav ; Holubová, Michaela ; Hůda, J. ; Kočvara, Luboš ; Kolařík, Tomáš ; Muška, Milan ; Peterka, Jiří ; Prchalová, Marie ; Říha, Milan ; Sajdlová, Zuzana ; Tušer, Michal ; Vašek, Mojmír ; Vejřík, Lukáš ; Kubečka, Jan
spontaneous development of populations and the influence of human interventions. For situations where a certain part of the fish population needs to be caught, within the project 'Biomanipulation as a tool for improving the water quality of reservoirs', we tested the available approaches in terms of their effectiveness and difficulty. The target species of catches were mainly cyprinid fish (bream, bleak, roach, rudd, white bream), which feed mainly\non zooplankton and tend to form very large populations. Among the most effective methods of catch during spawning are catches using electrofishing boats and fyke nets. In the non-spawning period, it is possible to carry out mass catches using trawl nets. Catches are effective both before spawning (in April) and during the summer. However, with repeated catches in the same places, their effectiveness decreases as a result of the fish being spooked. The efficiency of the catches partially improves again if the catches are repeated with a break of approximately 1–2 weeks. Catches also vary according to the stocking density of a given water body. With effective catches, the cost of catching 1 kg of fish is in the range of CZK 15–50.
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Populace pstruhů obecných v tocích jezer Čertova a Laka
HŮDA, Jan
In this thesis, almost ten years after the last large ichtyological survey, the populations of Brown trout (Salmo trutta L.) in two Šumava lakes (Laka and Čertovo) and adjacent streams were studied during spring and autumn electrofishing. The chemical parameters of local water were also sampled and compared with the past. The recovery of the studied area after an era of acidification was observed.
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Results of extended research of the ichthyofauna of lakes Laka and Čertovo, including adjacent streams.
Blabolil, Petr ; Hlaváč, J. ; Hůda, J. ; Kolařík, Tomáš ; Kortan, D. ; Muška, Milan ; Peterka, Jiří ; Vrba, Jaroslav
The report describes the results of an ichthyofauna survey in two areas of the Šumava National Park, where catches were made by an electric generator in the spring of 2021. This is the first direct evidence of natural reproduction of brown trout in the parts previously heavily affected by acidification.
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Results of the autumn extended research of the ichthyofauna of the lakes Laka and Čertovo, including the adjacent streams.
Blabolil, Petr ; Bartoň, Daniel ; Draštík, Vladislav ; Jůza, Tomáš ; Hladík, Milan ; Holubová, Michaela ; Hůda, J. ; Kočvara, Luboš ; Muška, Milan ; Peterka, Jiří ; Vrba, Jaroslav
The report describes the results of a unique survey of the ichthyofauna in two areas of the Šumava National Park, where catches were made by an electric generator in the autumn of 2021.
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