Among the most common endoparasites who infected small crustacean Daphnia pulex include microsporidia. These intracellular parasites appear to look like a simple single- celled organisms, but their cell structure and lifecycle prove the opposite. Microsporidia are species-specific. Although they infected most organisms of the animal kingdom, they are not yet sufficiently understood. This theses is inderectly followed up to the studies of waterflea Daphnia longispina and microsporidia Berwaldia schaefernai from the dam reservoirs The aim was to analyze closer microsporidian infection on host Daphnia pulex in a forest pool with simple enviroment, which included monitoring time dynamics of Daphnia population and identification infection caused by microsporidia Berwaldia singularis and yet unknown microsporidia labor-marked "HVH". Laboratory work included determination of zooplankton and parasites, calculation of prevalence, laboratory experiments with transmission of microsporidian infection between healthy and infected flea culture or by isolated spores. Genetic analysis of aquatic invertebrates from the forest pool, especially larvae of mite and mosquitos, helped make closer microsporidian life cycle and hypothesis about secondary hosts, for the presence of pathogen DNA using specific DNA...

This work involves the study of the effects of land use on the chemical composition of urban stormwater runoff, and its subsequent acute toxicity to the aquatic invertebrate Daphnia pulex. Samples were obtained from the Brunette drainage basin of Burnaby, British Columbia, from a variety of sites in the land use classifications commercial (C), industrial (I), residential (R) and open/greenspace (0). Results indicate that the toxicity to D. pulex and the chemical composition of the stormwater (measured by such parameters as COD, alkalinity, hardness, hydrocarbons and trace metals) were influenced by land use and the interval between rainfall events. The industrial and commercial land use sites were the major source of those trace metals most often considered toxic to aquatic organisms, with runoff from the commercial sites proving most toxic to the test organism (toxicity followed the sequence C>I>R»0). Bioassays with synthetic stormwater (Cu, Fe, Pb and Zn, at concentrations observed from field samples) demonstrated that pH and suspended solids helped to regulate the toxicity of the trace metals, and implicated the importance of these elements in natural stormwater toxicity. Statistical comparison between synthetic and natural stormwater runoff toxicity yielded poor correlation; however, this was expected due to the inherent differences between the laboratory and field environments. A detailed study of a single storm event indicated that while the "first-flush" of the storm may be contributing to toxicity through the physical scouring of insoluble pollutants, the soluble pollutants proved to be more toxic and were washed out of the area over the entire duration of the event. This prompted the author to propose the complete treatment of all stormwater runoff, and not simply the slug load of the first hour. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate