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Populačně genetická struktura pstruha obecného jako základ úspěšného obhospodařování lososových vod ve střední Evropě
KOHOUT, Jan
The genetic structure of 25 wild populations and five hatchery stocks from Czech Republic and Slovakia were analysed using mitochondrial (control region) and nuclear DNA (microsatellites, LDH-C1*) markers to elucidate the impact of stocking on central European populations of brown trout and to outline further management strategies. It seems that stocking practices have caused massive hybridisation between the Atlantic and Danube brown trout populations in the middle Danube basin and have led to a loss of among-population genetic variability in Slovakia and Moravia. Certain effect of stocking was detected also in the upper Danube, Vistula, Oder and Elbe River basins. However, the populations from the Elbe River basin keep certain level of among-population variability and seem to be less affected by stocking in comparison with the Danube River basin populations. There are some indications of late or post-Pleistocene penetration of the Atlantic basin trout to the Danube River basin. However, it is not clear to which extent the natural contact participated to the present distribution of Atlantic haplotypes and alleles in the Danube River basin. Samples from lower parts of the Danube River basin were therefore analysed using the same mitochondrial and microsatellite markers. Samples from Aegean Sea basin were included in order to reveal genetic variability of eastern Balkan populations and to estimate an impact of stocking in this area. Very low levels of introgression from Atlantic and other non-indigenous trout were found in the eastern Balkan populations. The genetic differentiation among the populations is substantially higher in this area compared to the central European populations. The populations in headwaters of the Otava River (Elbe River basin) were analysed using microsatellites in order to reveal origin of these populations and evaluate the current management strategies of brown trout in Šumava National Park and Protected Landscape Area. The analysed populations were substantially differentiated from the remaining Elbe River basin populations and there was also certain level of genetic structure within trout from the headwaters of the Otava River associated with isolation by a migration barrier and geographic distance. However, stocking with hatchery trout also contributed to the pattern of genetic variability. The population of Borová Lada hatchery, which is used for stocking in Šumava exhibited higher genetic variability compared to the wild populations and it seems to be of heterogeneous origin. Comparisons of the analysed populations with populations from other areas and results from other studies indicated that mtDNA haplotypes from the lower Danube River and southern Black Sea basins differ considerably from a subclade of the Danubian lineage consisting of haplotypes found so far in the most of the Danube River basin and in the Caspian and Aral Sea basins. The results thus evidence a complex evolutionary history of brown trout in the southern and western parts of the Black Sea basin.
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Food competition between stocked hatchery reared rainbow trout and native brown trout and grayling
BLASZCZOK, Roman
The aim of the work will be based on the diet composition monitoring of the introduced rainbow trout and wild brown trout and grayling in defined time intervals, and assessing the degree of the food competition among the monitored species. The experiment was held in the second half of September 2010 in the river Blanice in the protected fish areas close to the village Těšovice, where several dozens of rainbow trout were stocked. In a predefined several - day interval of were caught 30 pieces of the rainbow trout (SL = 266 ? 14 mm, m = 347 ? 54 g), 33 brown trout (SL = 244 ? 19 mm, m = 219 ? 51 g), 14 graylings (SL = 256 ? 27 mm, m = 240 ? 91 g) and 12 resident rainbow trout (SL = 255 ? 13 mm, m = 280 ? 47 g) originated from the last plant. Within these groups a fish stomach content and consequently food selectivity was examined by using of the Ivlev's selectivity index (1961), a food competition was examined by using of the Schoener's index food overlap (1970) and the importance of various food components was examined by using of the index of preponderance according to Natarajan (1961). Rainbow trout began to ingest food immediately after the stocking into the stream and its occurrence was seen in all fish crop caught during the period. The insect (Insecta) was given as a preferential food of the rainbow trout and according to the index of preponderance (IP), it formed 54%, Trichoptera (IP) 24% and Ephemeroptera (IP) 19% orders belonged to the most preferable kinds of the food. According to the index of preponderance, gastropod (Gastropoda) formed (IP) 25% of a secondary food. The rainbow trout was accepting the same dietary components as well as the original sorts of salmonoid fish within the river. According to the index of a food overlap (S), the food competition between rainbow trout and brown trout was equal to the value of (S = 0.566) during the whole monitored period and the grayling was equal to (S = 0.520). Even though both of these values are slightly below the significant food overlap (S = 0.6), we can still say that the food competition is relatively high among these kinds.
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Effect of the revitalization adjustments of small stream on fish society
ANTONÍN, Petr
The objective of my work was to consider the effect of the Mlýnský potok revitalization on its fish society. My work is based on the ichtyological researches made before and after the revitalization. The brook is situated at the Šumava mountain between the Lipno reservoir and the border with Austria. The revitalisation had a positive effect on biodiversity, abundance and fish biomass. At the same time are here described individual requirements for successful revitalization water stream and in particular fisches, to the these streams. In my work compare achieved results of postponements fishes of the three tracked brooks Horský, Bukový and Mlýnský
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Species variability of bentic organisms in Dračice river classicifed by PERLA system
KOUTNIK, Dalibor
Examination ecological size selected part of river (from village Františkov to border with Austria) on the basis of field watching. Observed results are analysed by system PERLA. Method is based on analysing biodiversity makrozoobenthos sample from fordables running water. Sampling can be apply in running water, where water column not exceed 1 m and speed of water stream to 1 m/s. Taking is made by normal or low water stage.
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Fish Management in the Locations with Occurence of Freshwater Pearl Mussel (Margaritifera margaritifera) in the Czech Republic
JIRUŠKOVÁ, Lenka
Quality of populations of brown trout (Salmo trutta m. fario) influence of occurence of freshwater pearl mussel (Margaritifera margaritifera) in river in the Czech Republic. Freshwater pearl mussel is a critically endangered species of animals. It does not have a very specific requirements only on environment but mainly on a specific host for holding glochidia (larval stage of pearl mussel). Thus fish management and migratory permeability of flow for support of existing populations is very important. Basic and essential precondition to support populations of freshwater pearl mussels is the presence of viable populations of brown trout, which represents the only suitable host glochidia. There are five locations with the biggest occurrence of pearl mussel in the Czech Republic - river basins the Blanice, the Teplá Vltava, the Malše, the Rokytnice and the Jankovský potok. The management of these flows is under local organizations of Czech Fishing Union, the National Park and Protected Landscape Area of the Šumava, the Secondary School of Fisheries in Vodňany and Faculty of Fisheries and Protection of Waters. The present management was found in the questionnaire for representatives of farming organizations. According to the answers in the questionnaire, the change of plans of restocking was recommended in the river basins of the Teplá Vltava and the Jankovský potok. There is the cooperation with the Germany was recommended in the river basin of the Rokytnice. The restoration of fish nursery is suitable in the river basin of the Malše. There is the first-rate population of brown trout in the river basin of Blanice, thus the continue in the present fish management for next support of this population in sequence on the populations of freshwater pearl mussel was recommended
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Fish husbandry in the mountains conditions at Borová Lada fish - hatchery in Šumava
PLIČKA, Vítězslav
Central parts of the Šumava national park has specific nature conditions which we must respect when fish farming is carry out . In 1998 fish {--} hatchery near Borová Lada was established. The fish hatchery exists more than 10 years and we still have no professional report about exploitation this object. (using assorted technologies of rearing, rearing under controlled conditions). The aim of this graduation thesis is evaluation results of trout culture and make proposition new improved technologic process in fish farming on this site. The thesis also includes experiments with initial feeding of fry of brown trout (Salmo trutta morpha fario) carryed out during the spring 2008. The main observed values were survivance, specific growth rate (SGR) and feed conversion ratio (FCR). After 17 weeks of initial feeding fry of brown trout the observed values were achieved: survival of fish 38,2 % , average length SL = 69,0 mm, average weight 4,9 g. Experiments showed that initial feeding of fry of brown trout (Salmo trutta morpha fario) with using feeding mixtures in the Borová Lada fish {--} hatchery is possible and effective.
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