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The design of the multipurpose small water reservoir
Šejnoha, Petr ; Menšík, Pavel (referee) ; Doležal, Petr (advisor)
The bachelor thesis deals with the simplified design of a small water reservoir in selected place near the village of Kadov. If serves to improve the countryside, fish farming and recreation. Part of the thesis is a discussion about the type and function of a small water reservoir and its water management solution. The design of the damis evaluated. A water balance is drawn up for the particular considered profile of the dam, which evaluates the specific drainage from the river basins, the evaporation and the leakage of water by the body of the simplified designed dam. This gives rise to a basis idea of the possibility of handling water in the tank. Terminology is based on the valid ČSN (Czech State Standart) and TNV (Technical standart water management). The current state of the countryside and the requirements of the Mayor were taken into account.
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Factors influencing the ecological stability of the Novozamecky rybnik Reserve
Hanzelka, Jan ; Reif, Jiří (referee) ; Čihař, Martin (advisor)
Fishponds and their surroundings are affected by many factors disrupting their ecological stability. In this thesis, influences of selected factors are evaluated. Particularly it is discussed excessive overgrowing of shoreline by plants, pond siltation by allochthonous material from catchment area, eutrophication process and intensive fish farming. It is presented the impact of these factors on local avifauna in Novozámecký fishpond National Nature Reserve and Special Protection Area and compared with Třeboňsko Special Protection Area. Birds use the ponds especially as nesting habitat and food source. Therefore, it is necessary to describe the influences disrupting this habitat. The frugal interference with mentioned processes is needed in terms of dynamics of the ecological stability. Thereby the requested fishpond parameters and ecological and economic values will be maintained. Fisheries management and lack of historical management in the form of reasonably performing mowing and grazing in the vicinity of the ponds has the greatest impact on the habitat of birds upon Třeboň fishponds. Novozámecký pond also suffers from the lack of historical management, but the unsatisfactory state of the pond is rather due to the overall eutrophication of the environment.
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Vliv zvolené strategie na efekt počátečního odchovu jesetera malého (Acipenser ruthenus) v kontrolovaných podmínkách
Dostál, Jan
The thesis summarizes findings from the field of initial rearing of sterlet (Acipenser ruthenus) that are currently available. The results of experimental rearing, which took place in 2014 and consisted of two parts, are included. In the first part, the impact of the exchange rate of the water in the tanks on change of hydrochemical parameters. For the experiment three variants in duplicate were prepared, with different flow rate for each one. The volume of water in the tanks was set to 100 liters and the number of fish was 150 fish/tank. Water change rate within the first variant was set for 1/3 of volume per hour, within the second variant for 1/3 of volume per hour and within the third variant for 3/3 of volume per hour. Each day was measured oxygen content, water temperature and pH, and samples for laboratory analysis were being taken. The results were analyzed by analysis of variance. No statistically significant difference has been found between monitored parameters, therefore these flow rates had no impact on the change of hydrochemical parameters for each variant. In the second part of the experiment was compared the effect of three different feed mixtures on growth parameters and development of fish. The same conditions of the rearing environment were maintained, but stocking density was reduced to 50 fish/gutter and a uniform water change rate of 3/3 volume per hour was set. The first variant was presented feed Aller Bronze 2 mm, the second variant Aller Silver 2 mm and the third variant Biomar Inicio 918 2 mm. At the beginning of the experiment, the fish reached an average piece weight of 29.00 g and FWC 0.44 within the first variant, 29.70 g and FWC 0.43 within the second variant and 29.31 g and FWC 0.41 within the third variant. At the end of the experiment the fish reached monitored parameters with following values: the first variant had the average piece weight of 37.99 g, FWC 0.41, SWGR 0.90 %.d-1, FCR 2.12 kg.kg-1 and PER 1,01; within the second variant, the average piece weight was 40.38 g, FWC 0.41, SWGR 1.02 %.d-1, FCR 1.82 kg.kg-1 and PER 1.18; within the third variant, the average piece weight was 43.51 g, FWC 0.40, SWGR 1.44 %.d-1, FCR 1.44 kg.kg-1 and PER 1.46.
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Ověření možnosti použití netradičních chovatelských postupů v chovu kapra obecného (Cyprinus carpio L.)
Kukačka, Vladimír
A series of four experiments has been made with the aim of monitoring the dynamic of change in the spectrum of fatty acids of common carp (Cyprinus carpio L.). In addition, the experiments also focused on the possibility of targeting changes in order to achieve a better dietary value of carp meat for human consumption. The changes in fatty acid spectrum of carp have been achieved by feeding of linseed and fish oil additions in a short interval, and by relaying fish with progressively decreasing temperature of water environment. From dietary point of view, the submission of feed containing 6 % linseed oil improved the FA spectrum of carp muscle when compared to the standard carp farming technology of cereal feed. The FA muscle fish spectrum, obtained due to the feed starting in early September 2008, endured without any considerable change through early January 2009. The application of fish oil is limited to qualitative composition. Through the addition of oils rich in EPA and DHA in the feed can effectively increase the content of the FA in muscle of carp.
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Effect of temperature, fish size and feeding on oxygen consumption and ammonia excretion in the Nile tilapia (Oreochromis niloticus)
DENKOVÁ, Adéla
Aim of this work were to assessed the impact of feeding, temperature, stocking density, fish size and water temperature on ammonia excretion and oxygen consumption of Nile tilapia (Oreochromis niloticus) in recirculating system. Concentration (saturation) of oxygen, water temperature and pH were measured using multimeter and concentration of ammonia was assessed by direct Nessler method. For assessing of effect of fish size, three groups of tilapias weighed 25, 65 and 140 g were established, each group in four replicates. For assessing of effect of feeding was tilapias (body weight 65g) divided into groups fed continuously, two meals per day and four meals per day, each group in four replicates. For assessing of effect of stocking density was tilapias (body weight 65g) divided into groups of 20, 50 and 80 kg.m-3, each group in four replicates. All experiments were performed for water temperature of 23, 27 and 31 °C and for fed and starved fish. Mean daily oxygen consumption was higher for smaller fish categories than for bigger ones and grow rapidly after feeding. The kind of feeding had impact on diurnal fluctuation of oxygen consumption. It was also confirmed that tilapia can survive low level of oxygen concentration for a quite long period.
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