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Progressive degradation of water ecosystems may contribute to the propagation of fungi pathogenic to humans and animals. The aim of this study was a quantitative evaluation and identification of species of potentially pathogenic fungi in the littoral zone of the Sulejów Reservoir used as recreation site. We studied samples of surface water and sediments collected from 6 sampling sites of the reservoir in the years 2000 and 2001. In 2000, fungi were isolated from 82.7% of samples, while in 2001 from as many as 95.4%. There were 28 species representing genera: Candida, Cryptococcus, Geotrichum, Kloeckera, Rhodotorula, Saccharomyces, and Trichosporon. The most common species were Rhodotorula glutinis and Candida guilliermondii. The density of the population of identified species depended on the season and sampling site and ranged from 80 to 328000 cells/dm³ (also uncountable growth). The waters of the Sulejów Reservoir may be a covenient place of anamorphic developmental forms, for the 15 cultured species which can also propagate in humans and other mammals.
The work aimed at the analysis of the structure and abundance of mollusc communities and their connection with environmental factors, especially the influence of Dreissena polymorpha. Molluscs were collected at 21 sampling stations within the Sulejów Reservoir in July 1999 and 2000 using Ekman-Birge's grab and bottom dredge. Generally fauna of molluscs was dominated by D. polymorpha, however in the upper part of the reservoir relative abundance of this species was low. The effect of zebra mussel on malacocenoses resulted in significant differences in species richness and densities between the habitats where this mollusc occurred in lower and higher abundance.
The aim of this research was estimation and comparison of denitrification rate in the Sulejów Reservoir using two methods: 1). the in situ chamber method – the denitrification rate was calculated from the total N2 flux out of the sediment, measured directly by gas chromatography and ranged from 0 to 677 μmoll N2 m-2 h-1. 2). occurrence of denitrifying bacteria – determined by means of the most probable number (MPN) and plate counting (PC). Environmental conditions determining denitrification process in the Sulejow Reservoir was also identified. The positive correlation between the content of organic carbon in the sediments and the amount of denitrifying bacteria (r=0.86) and denitrification rate (r=0.84) was indicated. The number of denitrifying bacteria in the sediment was estimated at 0.05% to 15.8% of total microflora by MPN, and at 4.6% to 26% using PC. The most frequently isolated bacteria were identified as members of the genera Pseudomonas, Alcaligenes and Bacillus. About 50% of the bacterial strains isolated accumulated nitrite during nitrate reduction.
Proper multidimensional management of perch, common and one of the most abundant species in European freshwaters, is a challenge both from ecological and commercial perspective. However, all activity relating to the management of the perch must be based on good genetic knowledge in order to ensure a purity of species and further conservation of biodiversity. Therefore, in the present study, the mtDNA cytb and D–loop restriction analysis was applied in order to estimate genetic diversity within and among three perch (Perca fluviatilis L.) populations in reservoirs of Central Poland: Sulejów, Próba and Jeziorsko. Two out of nine, and two out of eight restriction enzymes were polymorphic for cytb and D–loop, respectively. Five different haplotypes were detected with the simultaneous occurrence of haplotype 1 in all three populations. Nucleotide diversity values within investigated populations were low (0.003 to 0.02). No significant differentiation (P = 0.248) among populations representing two different catchments of Pilica and Vistula rivers, was observed. The lack of genetic differentiation of perch populations is the first important element for the development of a strategy to regulate the perch in Polish river systems, with simultaneous reduction of fish in eutrophic reservoirs and increase in amount of perch, in sites favorable for fishing and aquaculture.
The roach preferred branches of spruce and juniper as artificial spawning substratum rather than pine and birch. Perch preferred birch over conifers. Thus altering the availability of spawning substrata in the littoral zone should be effective in controlling the density and structure of juvenile roach and perch communities in reservoirs. Density dependent processes affects the early life history of fishes. Surveys in the Sulejow Reservoir in 1994 and 1997 provide an example of how increased availability of prey fish in the littoral zone may influence a predator population. During early summer age-0 pikeperch formed two discrete groups, one in the littoral and the other in the pelagic zone. In the littoral pikeperch became piscivorous at c. 3 cm on the numerous juvenile cyprinids, and grew relatively fast (5.2->9 cm by mid-July 1994). Those in the pelagic where prey fish were scarcer fed chiefly on zooplankton and grew relatively slowly (4.2-6.6 cm by mid-July 1994). From the resulting bimodal length distribution the upper modal group (littoral) had a higher probability of surviving their first winter. These data suggest a critical role for the ecotonal habitats in the dynamics of the trophic cascade, and show possibilities for controlling symptoms of eutrophication.
Excessive eutrophication causes the growth of microcystin-producing Cyanobacteria and leads to an increased human health risk. This paper reports the analyses of Cyanobacteria toxigenicity (the degree of potential toxicity) in lowland dam reservoir (Sulejów Reservoir, Central Poland) by the use of PCR-based methods. The reservoir (area 22 km², mean depth 3.3 m) is very eutrophic water body permanently blooming with blue-green algae (mainly Microcystis aeruginosa). For identification of cyanobacterial genus the 16S rRNA region was used. Cyanobacterial genus was detected during the whole monitoring period in summer 2003. The potential toxicity of cyanobacteria was determined by amplification of selected mcyA,B,E genes in the microcystin biosynthesis pathway. All of the analyzed genes were detected at the beginning of the growing season during low cyanobacterial biomass (0.67 mg l⁻¹). 89% of the samples were found to be positive for mcyA detection. Early detection of mcy genes at the beginning of summer preceded a period of the highest microcystins concentration (2.91 µg l⁻¹ in maximum) and toxicity established by ELISA (enzyme-linked immunosorbent assay – enables determination of microcystins concentration) and PPIA (protein phosphatase inhibition assay – enables estimation of microcystins toxicity). We show that toxigenic (potentially toxic) strains of cyanobacteria occurred in Sulejów Reservoir throughout the summer and genetic markers were effective in early identification of microcystin-producing genera. Application of molecular methods in parallel with toxicity testes can provide complete information to prevent any human health risk.
The eutrophication of the Sulejów reservoir dam in Poland is connected with the problem of toxicity of cyanobacterial blooming (blue-green algal blooming). The main species responsible for hepatotoxic ”algal bloom” formation is Microcystis aeruginosa. The aim of this study is to evaluate the influence of the toxic cyanobacterial extract containing microcystins on the growth and morphology of a water plant (Spirodela oligorrhiza) and animal cells (rat hepatocytes). A higher concentration of cyanobacterial extract (MC-LR = 343 µg/dm3) reduced the number of fronds by about 50% in comparison with the control. The extract affected the reduction mass of fronds and the concentration of chlorophyll. The activity of the constitutive acid phosphatase decreased. The first morphological changes in rat hepatocytes typical of apoptosis were observed after 30 minutes of incubation with the cyanobacterial extract. The hepatocytes underwent cell membrane blebbing (MC-LR = 100 µg/dm3). The next 30 minutes of incubation caused an increase in the percentage of deforming cells of more than 50% (MC-LR = 100 µg/dm3). High chromatin condensation and apoptotic bodes were observed in 90% of cells after 120 minutes (MC-LR . 500 µg/dm3). The results of studies confirm the high toxic and cytotoxic effect of blue-green algal blooming from Sulejów reservoir on both plants and animals.
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