National Repository of Grey Literature 28 records found  beginprevious13 - 22next  jump to record: Search took 0.00 seconds. 
Report on the status of the burbot populations in the Karhov, Lučina, Nýrsko and Zhejral reservoirs and Obecník Pond in 2016
Blabolil, Petr ; Jůza, Tomáš ; Matěna, Josef ; Muška, Milan ; Peterka, Jiří ; Říha, Milan ; Vejřík, Lukáš
The aim of the study was to monitor the burbot populations in four reservoirs and in a pond with previous stocking. The monitoring was carried out during the spring season 2016 and, in the case of the Nýrsko Reservoir, during winter and summer as well. The combination of harmless methods (traps of two types, visual survay, electrofishing, hydroacoustic), a method simulating fishing pressure (long-lines) and a fix-frame trawl were used to detect burbot. A novel monitoring scheme was developet and validated and burbot populatin characteristics described.
Importance and species composition of non-fish prey in the diet of fish-eating predators
Mach, Jakub ; Čech, Martin (advisor) ; Vejřík, Lukáš (referee)
Piscivorous birds are usually considered to be exclusive fish eaters which are responsible for signifiant numerical and economical losses to fish populations. With a method of literary research the importace and species composition of non-fish prey is determine in the diet of selected fifteen species of piscivorous birds. The aim of this work is to determine the extent of non-fish part of the diet of particular piscivorous predators and categorize them on the grounds of differences between size of this part in their diet. Another goal is to determine any effects which can influence amount and species composition of non-fish part of nourishment, and also factors, which can influence obtained results based on the chosen method of analysis. According to the data found, diet of five bird species was composed almost exclusively with fish. Eight other bird species also showed preference for fish prey, but in most of these cases was present also important part of non-fish prey. Two bird species seems to be very oportunistic in case of composition their diet. As factors that can affect the extent of non-fish part in the diet was established especially the prey availability in environment, used method for diet composition analysis, insufficient attention for parts of prey other than fish, or also less...
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
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).
A new tool for improvement the quality of water ecosystems
Blabolil, Petr ; Říha, Milan ; Peterka, Jiří ; Prchalová, Marie ; Vašek, Mojmír ; Frouzová, Jaroslava ; Jůza, Tomáš ; Muška, Milan ; Tušer, Michal ; Draštík, Vladislav ; Ricard, Daniel ; Sajdlová, Zuzana ; Šmejkal, Marek ; Vejřík, Lukáš ; Matěna, Josef ; Borovec, Jakub ; Kubečka, Jan
The Czech multimetric fish based index (CZ-FBI) was developed recently. The aim of CZ-FBI is to assess the ecological potential of heavily modified and artificial water bodies and to detect ecosystems, particularly their specific components, in unsatisfactory conditions. This article describes steps of CZ-FBI development. Since the philosophy used, particular events presenting the results, to recent stage. CZ-FBI is a part of certified methodology of the Ministry of the Environment of the Czech Republic and the comparison with other assessment methodologies within a geographical intercalibration group is in process.
Investigation of Cladophora sp. distribution in the Brno reservoir, conducted under the project “The implementation of management measures at the Brno reservoir, phase II 2013-2017
Borovec, Jakub ; Matějíčková, Ivana ; Vejřík, Lukáš ; Kočvara, Luboš ; Hauer, T.
The occurrence of the green alga Cladophora and other macrophytes in the Brno reservoir was confirmed. The distribution of Cladophora stands was assessed as not dramatic, despite of the temporary occurrence of a mass of surface-floating filaments. This increase in buoyancy of the Cladophora colonies was caused by excessive oxygen production in the co-growing algal species (Tetraspora sp.).
Research on reproductive biology of asp Leuciscus aspius and its sampling during 2008 and 2014 in Švihov reservoir
Vejřík, Lukáš ; Bouše, Eduard ; Matějíčková, Ivana ; Ricard, Daniel ; Kubečka, Jan
Based on electrofishing for asp in main tributaries of Švihov reservoir and subsequent tagging of captured fish, size and age composition of asp spawning stock together with the importance of primary and secondary tributaries for spawning and asp growth was evaluated in years 2013 and 2014. Survival of fish tagged in previous years 2008-2012 was estimated as well.
Hydrobiological monitoring of Medard lake in 2011
Kubečka, Jan ; Blabolil, Petr ; Borovec, Jakub ; Čech, Martin ; Draštík, Vladislav ; Hejzlar, Josef ; Nedoma, Jiří ; Peterka, Jiří ; Prachař, Zdeněk ; Rychtecký, Pavel ; Seďa, Jaromír ; Vejřík, Lukáš ; Znachor, Petr
The report summarizes results of research on limnological components of lake Medard (former opencast mine Medard-Libík) achieved in 2011, and suggests recommendations for further monitoring of the lake.
What do the fish say about the quality of aquatic ecosystems
Blabolil, Petr ; Říha, Milan ; Peterka, Jiří ; Prchalová, Marie ; Vašek, Mojmír ; Jůza, Tomáš ; Čech, Martin ; Draštík, Vladislav ; Kratochvíl, Michal ; Muška, Milan ; Tušer, Michal ; Frouzová, Jaroslava ; Ricard, Daniel ; Mrkvička, Tomáš ; Sajdlová, Zuzana ; Vejřík, Lukáš ; Šmejkal, Marek ; Borovec, Jakub ; Matěna, Josef ; Boukal, David S. ; Kubečka, Jan
The first Czech methodology for the assessment of ecological potential of heavily modified water bodies and artificial water bodies based on fish communities was developed. The first step of developing the methodology was preparing the typology of water bodies. The typology distinguishes between water bodies of different altitudes and with and without thermal stratification. Fish were sampled by multimesh gillnets following European standard procedures. The selection of fish metrics was based on statistical analyses in which metrics (fish community indicators) were correlated with the most common stressor – eutrophication. The analysis detected several sensitive metrics (metrics showing the best correlation with the stressor) in which ecological class boundaries were set. Afterwards, combination of sensitive metrics was used for calculation of the ecological quality ratio (EQR) for each of the reservoir sampled. The EQR expresses the deviation between a reservoir’s current ecological status and its maximum potential. The next step consisted of validating the EQR with an independent pressure index and verifying the time stability of ecological potential assessment. The metrics used in the methodology fulfill all the obligations set forth in the Water Framework Directive (2000/60/EC), which include assessment of the composition, abundance and age structure of fish fauna.

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12 VEJŘÍK, Lukáš
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