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Vliv biomanipulací s účelovou rybí obsádkou na vývoj kvality vody vodárenské nádrže Hamry
Jurek, Lukáš
I have dealt in my thesis with biomanipulation on the water reservoir Hamry. The reservoir is located near the village Hamry in the Bohemian-Moravian Highlands, it is meso-eutrofního character and its size (about 42 ha of water surface) and an average depth of 2 m is ranked among the smaller, shallow tank. Biomanipulation measures are there implementation and monitored in the long term (since 2008).Biomanipulation implemented in 2015, which mainly consist of removing unwanted species of fish from the reservoir were implemented by different methods at all ontogenetic levels of fish. That means collecting eggs perch Perca fluviatilis, L., seinings of juvenile stages panktivorous species of fish, as well as seinings and elimination of adult unwanted fish species. Part of the seinings were catching spawning shoals of bream Abramis brama, L. and roach Rutilus rutilus, L. With those biomanipalition actions was carried collection and evaluation of samples of zooplankton, phytoplankton, hydrochemical analyzes and physico-chemical parameters of water. Also were investigated phosphorus content in sediments. Some of the data I obtained and evaluated actively (especially zooplankton), other data were evaluated by specialists from ÚBO AV ČR Brno, or employees of the Department of Fisheries and Hydrobiology at the Institute of Zoology, Fisheries, Hydrobiology and Apiculture MENDELU Brno and I have only used this data to compare the efficiency of the imlpemented biomanipulation.
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Growth of aquatic vegetation in fish ponds used for recreation - Bolevecká soustava near Plzeň.
Pták, Martin ; Duras, Jindřich (advisor) ; Potužák, Jan (referee)
The aim of this diploma thesis was to clarify the differences among three different ponds (Bolevecký, Třemošenský, Šídlovský) situated in Pilsen. All of the above mentioned ponds are recreational areas where Bolevecký pond is best known for his water quality improvements since 2006 (after application of Fe and Al - colagulants and also fish - stock changes). The main difference was based on the growth of submersed water plants. The macrophytes were growing slowly or not at all in Bolevecký pond. There was a huge expansion of macrophytes (mainly Myriophyllum spicatum species) in Třemošenský and Šídlovský ponds therefore the water plants must be regulated during summer seasons by mechanical harvesting. The water in all three ponds proves the same qualities but the differences may be found in the nutrient composition of sediments. The fractionation analysis (the founders Psenner and Puczsko) confirmed the fact that all localities are poor in phosphorus however the differences were found in content of iron. The increased content of iron was observed in sediments of Šídlovksý and Třemošenský ponds (mainly in BD fraction - the iron was unstable under redox potential changes). The result of this analysis proves that phosphorus is potentially more available for macrophytes in sediments of Třemošenský and Šídlovský...
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DEVELOPMENT OF ICHTIOFAUNA IN THE NEW FILED POND CHABAŘOVICE
ŤUK, Josef
The Chabarovice coal mining pit arose by flooding the former strip mine area for brown coal. After filling, the pit area should reach about 225 hectare, total volume of water 34.4 mil. m3, average depth 15,6 meters with maximum of 23,3meters. It is assumed that the pond and adjacent areas will be used for recreation usage after completion of recultivation and ground shaping. I have performed the investigations in June and in August 2004 - 2005, using basic ichthyological methods. The data about recruitment were collected by the littoral seine net and adult fish (older than one year) were investigated by gillnets nets. Fish was determinated to genus, individually measured by slide caliper (fry) and by measuring plate (adult fish). The lenght of fish body (SL-standart lenght) was measured in millimeters and fish were weighted separately (W v g). In the year 2005, also scales were taken from individual fish for the age assesment. Obtained data were processed with regard to performed biomanipulation measures in individual sectores. Nine fish species and one hybrid were recorded by the monitoring with gillnets nets. The most numerous fish were juveniles and adults of rudd with SL 74 {--} 300 mm and the weight up to 618 g. The fish species with the strongest impact upon the pit ecosystem function is conitnuously the perch with the dominance of individuals with SL 46 to 337 mm and weight zup to 850 g.
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Food of predatory fish during the flooding of the Chabařovice coal mining pit
KABILKA, Petr
The Chabařovice coal mining pit is currently still under the process of continuous flooding and its area increased up to 174 ha since 2001.Adult perch (Perca fluviatilis) have been the most numerous fish of the lake until 2004. Fish were collected during the ichtyological survey sampling campaigns in June and September.Diet composition was expressed as percent weight, which was calculated for each prey taxon.
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