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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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Spatiotemporal distribution and shoaling behaviour of fish (Časoprostorová distribuce a hejnové chování ryb)
SAJDLOVÁ, Zuzana
The dissertation thesis is focused on pelagic fish distribution in the large freshwater bodies and the main factors affecting it. Paper 1 describes fish behaviour in a mouth of a midwater trawl during different day time periods as fish activity may importantly affect abundance estimates of the sampled fish stock. Acoustically recorded avoidance behaviour in a vertical direction is described. The second part of the thesis refers to the diel distribution and behaviour of the pelagic fry communities with a particular focus on the vertically migrating bathypelagic percid fry that occupy open water during early ontogeny. Paper 2 shows that the vertically migrating community can create a dominant part of fry assemblages in the reservoir, which is in contrast to many previous observations of an usually prevailing non-migrating epipelagic community. At their day refuge, bathypelagic percid fry (BPF) created dense shoals whose physical parameters are described. Paper 3 for the first time demonstrates that vertical shifts of BPF were under direct light control, hence were not a genetically fixed behaviour. A unique large-scale field experiment with the simultaneously operating up-looking and down looking transducers was carried out under artificially controlled light regime. Moreover effect of predation as the main ultimate cause of vertical shifts is discussed. The introductory part of the thesis opens with the current possibilities of assessing distribution and behaviour of fish in the open water. Benefits of shoaling/schooling behaviour during defence against predators, foraging and learning abilities of fish are mentioned and some implications of fish behaviour on the fish capture process are pointed out. The second chapter deals with the diel shifts between habitats that belong among the most common activities of fish. However, distribution of fish varies also over the long temporal scale and currently has been strongly affected by changing climate. Therefore, the main affects of climate change on the world´s fish populations are introduced using examples from both freshwater and marine environment.
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Permanent Vascular Access for Haemodialysis with Regard to Diabetes Mellitus Diagnosis
Sajdlová, Zuzana ; Eislerová, Iva (advisor) ; Hocková, Jana (referee)
This bachelor thesis deals with the issue of permanent vascular access for hemodialysis with regard to presence of diabetes mellitus (hereinafter DM). It focuses on peripheral hemodialysis vascular access, which include the arteriovenous fistula (AVF) and arteriovenous fistula created using synthetic material, such as graft (hereinafter AVG). The main objective is to highlight the fact that the vascular system is often affacted by systemic diseases like diabetes or atherosclerosis and creating AVF in such patients is often a complicated matter. By intensive postoperative monitoring imminent complications may be detected and prevented. The research is focused on peripheral HCP (AVF, AVG) and on detecting differences in dependance on their individual representation and their functional characteristics at 40 patients treated in Department of Internal Medicine Strahov, General Teaching Hospital Prague. The average age was 70 years. The first group consisted of 21 patients with DM and a the second group 19 non-diabetic paients. AVF is preferable to AVG even in patients with DM. The actual values of blood flow were measured by a team of nurse and clinical engineer and calculated using special formulas from reagular measurements in both groups of respondents. The obtained values of acutal blood flow have...
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Ichthyological surveys of the Nýrsko and Karhov reservoirs and investigations of abundance, age composition and spawning dynamics of asp population in the Želivka Reservoir in 2015.
Vašek, Mojmír ; Soukalová, Kateřina ; Kočvara, Luboš ; Blabolil, Petr ; Baran, Roman ; Frouzová, Jaroslava ; Koliada, Ievgen ; Muška, Milan ; Šmejkal, Marek ; Draštík, Vladislav ; Kolařík, T. ; Prachař, Zdeněk ; Sajdlová, Zuzana ; Vebrová, L. ; Vejřík, Lukáš ; Kubečka, Jan
The species composition and the relative abundance and biomass of fish communities in the Nýrsko and Karhov reservoirs were evaluated by means of standardised multimesh gillnets. The spawning stock of asp in the Želivka Reservoir was individually marked using PIT tags and the density and behaviour of tagged fish at the main spawning grounds were examined through the whole spawning season. The total number of reproducing individuals in the asp population was estimated. The sex-specific length and weight growth rates of adult asp in the Želivka Reservoir were also calculated. \n\n
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The report on the asp and spined loach populations’ status in SCI – valley reservoirs.
Blabolil, Petr ; Šmejkal, Marek ; Bartoň, Daniel ; Baran, Roman ; Draštík, Vladislav ; Jůza, Tomáš ; Kočvara, Luboš ; Koliada, Ievgen ; Kolařík, T. ; Matějíčková, Ivana ; Prachař, Zdeněk ; Sajdlová, Zuzana ; Soukalová, Kateřina ; Vebrová, Lucie ; Vejřík, Lukáš ; Kubečka, Jan
The aim of the ichthyological survey was to assess the status of reproductively active population of asp (Leuciscus aspius) in the SCI (site of community importance) Želivka (Švihov Reservoir) and spined loach (Cobitis elongatoides) in the SCI Nová Říše (Nová Říše Reservoir).
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