National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Seasonal dynamics and vertical distribution of Crustacea in the deep stratified reservoir Josefův Důl (the Jizera Mountains, Czech Republic)
Adámek, Radek ; Hořická, Zuzana (advisor) ; Vrba, Jaroslav (referee)
The zooplankton of Josefův Důl, a large and deep drinking water reservoir recovering from acidification, develop in relation to the improving water chemistry but also predation by salmonid fish re-stocked at the end of the 1990s. Crustacea are represented by small numbers of several species only, and nothing is known about their distribution in the water column. Recently, picocyanobacteria Merismopedia sp. became dominant in the phytoplankton, which hampers substantially the treatability of the raw water. The aim of the thesis is to describe the seasonal dynamics and vertical distribution of Crustacea in the Josefův Důl reservoir, together with parameters of the environment, and to study their possible diurnal vertical migrations in the summer period.
Changes in spatial distribution of gelatinous zooplankton: causes and consequences
Krylová, Pavla ; Petrusek, Adam (advisor) ; Rulík, Martin (referee)
During the day, changes in the spatial distributions of organisms in the water column occur repeatedly, especially in diurnal vertical migrations, which affect abiotic and biotic components of ecosystems. The migratory behaviour occurs worldwide in the oceans and in fresh water, in different habitats and under different physical conditions. The main migrants are gelatinous zooplankton, which are a heterogeneous group of invertebrate animals, although phytoplankton, nekton and other representatives of zooplankton also migrate. The main focus of the study of diurnal vertical migrations is proximate and ultimate factors that influence the migration. Furthermore, occurrence and density of organisms are examined. To study vertical migrations of gelatinous zooplankton, it is the easiest to study jellyfish because of their size. The distribution behaviour might also be observed in freshwater zooplankton. Two university studies of diurnal vertical migration of freshwater jellyfish were executed in previous years. This work aims to: summarise the current knowledge about spatial distribution - especially of diurnal vertical migration, describe in detail proximate and ultimate factors and compare them between freshwater jellyfish, gelatinous zooplankton and jellyfish. Key words: gelatinous zooplankton,...
Diurnal vertical migrations of zooplankton in a stratified mountain reservoir
Adámek, Radek ; Hořická, Zuzana (advisor) ; Stuchlík, Evžen (referee)
The thesis - a literature review - was aimed at the phenomenon of diurnal vertical migration (DVM) of zooplankton, in relation to particular conditions in the Josefův Důl reservoir in the Jizera Mountains (northern Bohemia, Czech Republic). The area of the Jizera Mts has a very sensitive geology, and thus suffered a strong anthropogenic acidification in the second half of the 20th century. The consequence was a long-term degradation of chemistry and biology of soils and surface waters. The waters in the upper plateau of the mountains were fishless, with a low diversity and biomass of both the phytoplankton and zooplankton. Recovery from acidification is slowest in the deepest reservoir, Josefův Důl. Due to its morphology, thermal stratification, newly re-stocked brook charr population, and invertebrate predators' occurrence, the zooplankton distribution in the vertical profile is expected to be irregular, with DVM. The following diploma project, oriented to seasonal changes and vertical distribution of the zooplankton in the Josefův Důl reservoir, should contribute to long-term data on biological recovery of the reservoirs from acidification, and explain the role of biotic parameters in zooplankton succession.