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Je vysazování rychleného plůdku lipana podhorního vhodným postupem pro podporu tohoto druhu ve volných vodách?
PASTEJŘÍK, Jan
This thesis focuses on the possibilities of supporting or restoring populations of the brown trout in Czech streams. Due to the effects of many negative factors, the populations of brown trout in our streams have significantly decreased, and the artificial introduction of reared individuals has so far proven to be ineffective. The aim of the thesis was to assess the possibility of strengthening or restoring the population of brown trout in selected sections of streams by introducing quick-growing fry reared in pond conditions. A significant number of recaptured individuals in all monitored locations indicates that the fish are capable of surviving and prospering in a new environment. During recaptures, it was found that the introduced fish formed a significant proportion of the fish communities present in the experimental sections. Successful overwintering of some of the introduced individuals was demonstrated in all locations. The use of alizarin solution as a bath for marking brown trout fry is an appropriate method for the efficient marking of a large number of small individuals with the possibility of detecting marks in the field without the need to kill identified individuals. The production and introduction of quick-growing fry of brown trout appear to be a promising approach for restoring and supporting their populations in free waters.
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Hydrochemical characteristics of selected fishponds in the current conditions in relation to the basin management.
PERGLOVÁ, Veronika
Fishponds and their ecosystems perform a number of important functions. Except to their economic importance, ponds contribute to the formation of the landscape, the local climate, increase biodiversity and affect the retention of water and its quality. Rod Pond is in a protected nature reserve, and therefore it is in a modified economic regime, compared to other ponds in the Třeboň region. Due to the limitations of the semi-intensive economic farming system in recent years, the pond and its shores are an important home for waterfowl, amphibians and other organisms. Rod Pond is also very importance in the retention and conversion of various forms of phosphorus and nitrogen, thereby it reduce eutrophication and it contributes to improvement of the water quality. In this work was evaluated the seasonal (2019) and long-term development (se-lected years in the period from 1992 to 2019) of physicochemical indicators of water quality in the Rod pond in relation to fisheries management and river basins. It was evaluated impact of the water chemistry in depend on the sampling profile on this fishpond Rod, including the analysis of sediments from these various sampling locali-ties. Concentrations of the main nutrients of the sediments were compared with the analysis of the sediment from 2015, which showed that the sediment is still increas-ing the concentrations of nitrogen and phosphorus. Overall, the fishpond Rod shows itself like dynamic ecosystem. Despite the above-mentioned precautions in the fish management, fishpond is still hypertrophy, although it shows much lower levels of total phosphorus and chloro-phyll than it flows from the fishpond Naděje. To improve the quality of water in the fishpond and in the whole catchment area, it is important to limit the high inputs of nutrients into catchments basin and to reduce its own internal nutrient load by using the method of differentiated removal of part of the sediment.
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Long-term trends in water quality of pond Světin relation to fish management
Altmann, Martin ; Duras, Jindřich (advisor) ; Vrba, Jaroslav (referee)
Fishpond ecosystems provide many other services besides fish production. One of them is the retention of nutrients and thus ability to change the quality of the through flowing water, thereby ability to influence the overall quality of surface waters. In the case of the fishpond Svět in Třeboň it is also recreation, as the pond is an integral part of the tourism of the town. Water quality in the fishpond and its retention capacity of phosphorus is connected with the fish management and the inflow of nutrients from the catchment basis, especially within a cascade of ponds and densely populated or agricultural regions. This thesis evaluates seasonal (2013, 2015) and long term (2007-2015) trend of water quality of pond Svět in Třeboň in relation to fish management. Furthermore, mass balance was calculated for 2015 and estimated for 2013. The years 2015 and 2013 (the first years of production cycle) varied considerably in amount of annual rainfall. The year 2015 was extremely dry and 2013 very aqueous. Different hydrological conditions caused different seasonal courses in hydrochemistry parameters and its concentrations. The water quality of fishpond Svět is in the most of parameters better in comparison with other production fishponds in the Třeboň region and also the intensity of fish management is...
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Inpact of fishery management on the structure and dynamics food sources and environmental conditions in selected fispond areas.
BAXA, Marek
The observation was carried out in twenty fishponds in the surrounding of Vodňany and seven fisponds in the surrounding of Třeboň. The aim of the work was to evaluete the quality and quantity of the zooplankton depending on fish production. The samples were obtained and the observations were realized during the 4 years in Vodňany fishponds area and during the 2 years in Třeboň fishponds area. At first the samples were collected and data about the observed localities were organized. These data should explain changes in the aquatic ecosystems of these fishponds areas during the last decades.
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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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