National Repository of Grey Literature 45 records found  1 - 10nextend  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.
Age structure and growth of wild brown trout in relation to population density and habitat quality
Závorka, Libor ; Slavík, Ondřej (advisor) ; Matěna, Josef (referee) ; Reichard, Martin (referee)
Brown trout Salmo trutta L. is a fish species with high socio-economic value, which is favourable among anglers and a successful invader worldwide. The aim of this thesis is to explore environmental factors affecting body growth and survival of brown trout with emphasis on density dependent selection in juvenile life stages. This thesis is specifically focused on: (1) effect of population density on growth and survival with respect to a dynamic of a local group of individuals (papers I and II); (2) effect of inter-individual differences in behaviour on the relationship between individuals life-history traits and available resources (papers III and IV); (3) link between demo-genetic structure of population and growth and mortality rates of individuals (papers V, VI and VII). Datasets for this thesis were collected during a long-term mark-recapture study on wild brown trout population (2005-2011) in the catchment of the Otava River in Šumava National Park (Czech Republic) and a set of field and laboratory studies conducted on wild populations in streams on west coast of Sweden. In accordance with some previous studies, this thesis showed that growth of juvenile brown trout is negatively affected by population density. Nonetheless, this thesis reveals that the negative effect of density dependent...
Freshwater macroinvertebrates and their use for assessment of environmental changes in running waters
Kolaříková, Kateřina ; Stuchlík, Evžen (advisor) ; Matěna, Josef (referee) ; Porcal, Petr (referee)
The dissertation thesis consists of five articles, bringing together results from investigations of macroinvertebrates in running waters. The use of freshwater macroinvertebrate organisms to assess environmental changes was based on the following facts: a) the presence/absence of taxa provide information about abiotic factors and/or about the pollution status of the site, b) they are indigenous and sedentary species, so that the environmental implications can be related to the site they live on, c) the organisms accumulate xenobiotic elements or compounds, thus reflecting the contaminant level in the environment. Localization of the sampling sites was related to the "hot-spots" of environmental problems. The particular investigations were carried out in the Elbe River catchment and in the Czech mountains on the selected headwater streams of the GEOMON network of the Czech Geological Survey. The Elbe was considered one of the most polluted rivers across Europe in the second half of the past century until the socio-economic transformation after 1989. The headwater streams in the Czech Republic were chosen with respect to the problem of acidification. The ability of bioaccumulation of xenobiotics in macroinvertebrate organisms was used to assess the long-term load of the Elbe ecosystem with trace...
Factors influencing movement and behaviour of animals in riverine environment
Horká, Petra ; Petrusek, Adam (advisor) ; Matěna, Josef (referee) ; Kováč, Vladimír (referee)
Animals living in riverine environments are influenced by various abiotic and biotic factors which shape their behaviour. Among the most distinctive behavioural traits by which animals react and adapt to environmental variability is movement behaviour. In my study I focused on movement and distribution of several species and their response to environmental and anthropogenic factors. The thesis consists of two parts: the first part synthesizes studies on behaviour of European grayling Thymallus thymallus, ide Leuciscus idus and an invasive crustacean Hemimysis anomala; the objectives of individual projects were to determine which environmental factors influence the species' behaviour and how. The first two chapters present extensive radio-telemetry studies which examined diel movements and migration of ide (one year observation in the River Elbe) and European grayling (study conducted in autumn-winter periods of three consecutive years in the River Blanice, focusing on differences between juveniles of wild and hatchery origin). The third study was also conducted in the Elbe and evaluated the diurnal behavioural patterns and spread of the Pontocaspian mysid shrimp Hemimysis anomala. The second part of the thesis consists of two chapters focusing on young-of-the-year (YOY) fish assemblages: the first...
Distribution patterns and habitat requirements of the species of the family Cobitidae in Slovakia
Pekárik, Ladislav ; Švátora, Miroslav (advisor) ; Ráb, Petr (referee) ; Matěna, Josef (referee)
Distribution patterns and major environmental correlations of the species of the family Cobitidae are presented here. All three species are still relativem widely distributed in Slovakia. Comparing with the past, no rapid ganges have been found. However, river regulation, pollution and the lowland amelioration affected the distribution of these species. Following the results of the occurrence of Balkan spined loach (Sabanejewia balcanica) within the mesohabitat scale, distance from source, slope, water depth and vegetation cover are the most influential variables in the proposed model. All these variables that contribute to our model explanation determine the stream morphology that affects the consequences of local temperature conditions and other abiotic factors as oxygen amount. Switching to microhabitat spatial scale, several microhabitat variables significantly influence the spatial distribution of analysed species. Depth more than 40 cm, refuges stones and point near bank (<15% of river width) are the most influential ones supplemented with substratum sand, substratum cobbles, substratum boulders, no refuges, refuges woody, depth 0-10 cm and maximum velocity none. Balkan spined loach occurs in the microhabitats occupied also by young-of-the-year (YOY) individuals and common minnow (Phoxinus...
Influence of environmental factors on fish assemblages in streams of the Elbe and Oder basins
Kůra, Luboš ; Švátora, Miroslav (advisor) ; Matěna, Josef (referee)
ABSTRACT The effects of environmental parameters on changes in the structure of fish assemblages were studied in the Elbe and the Odra river basin. Research was done at 819 sites that were surveyed in the field during the period between 1993 and 2007. The impact of 46 factors derived from the maps through a geographic information system was tested as well as the impact of 10 factors recognized in the field. To evaluate the influence of these factors the indirect (Detrended Correspondence Analysis, DCA) and direct (Canonical Correspondence Analysis, CCA) multivariate cluster analysis were used. Analyses were performed with data on presence-absence and relative abundance of each species. DCA well reflects changes in assemblages in the longitudinal profile of streams. CCA refers to a significant influence of regional and temporal variability and influence of individual factors. The fish assemblages are best characterized by the analyzed factors of distance from the source location, stream slope, altitude of locality, representation of arable land in the basin, number of ponds in the sub-basin above the locality, type of waters (salmonid or cyprinid), and water temperature (the only of the parameters of the field). The analyzed factors better reflect the variability in fish assemblages of the Odra...

National Repository of Grey Literature : 45 records found   1 - 10nextend  jump to record:
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1 Matěna, Jakub
1 Matěna, Jiří
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