Динаміка фітопланктону у міських водоймах з різним ступенем антропогенного навантаження

Abstract

У роботі наведено особливості динаміки фітопланктону водойм міста Житомир з різним ступенем антропогенного навантаження, представлено результати дослідження таксономічного складу та кількісних показників розвитку фітопланктону, подано характеристику екологічного стану водойм.

В работе приведены особенности фитопланктона водоемов города с разной степенью антропогенной нагрузки (на примере прудов г. Житомира), представлены результаты исследования таксономического состава и количественных показателей развития фитопланктона, дана характеристика экологического состояния водоемов.

Water bodies which are located in urban areas are exposed to severe human pressure. This leads to disruption of the structure and functioning of aquatic ecosystems in general and phytoplankton in particular. The paper deals with the phytoplankton peculiarities of urban water bodies with differing degrees of human pressure (evidence from the ponds of Zhytomyr, Ukraine). The pond in Kroshnianskyi Arboretum Park and Sokolovskyi pond (under a higher anthropogenic load) were examined here. The spring-autumn phytoplankton samples of ponds were taken as material for the research. Phytoplankton samples were studied by general hydrobiological methods. Some indicators of hydrochemical and hydrophysical regime in reservoirs were determined. Bioindication analysis of algae list was made. 109 species of algae, represented by 112 intraspecific taxa including those containing the nomenclature type species, were found in phytoplankton of Kroshnianskyi Arboretum Park and 146 intraspecific taxa in Sokolovskyi pond over the research period. Diatoms, green algae, euglena algae and dinophyta comprised the core of biodiversity of both water bodies. The most significant proportion of Chlorophyta and Bacillariophyta was in the formation of abundance and biomass of phytoplankton. However, Cyanoprocaryota prevailed in the pond with a higher degree of anthropogenic load. Cyanoprocaryota also dominated in summer and caused water bloom. Comparative analysis of species content of phytoplankton in the given water bodies with the help of Sorensen coefficient showed low similarity. Inverse correlation with the water transparence and dynamics of quantitative diversity and numbers of phytoplankton was observed in ponds with higher anthropogenic load. Phytoplankton peaks, different in structure and duration, were detected, mainly due to the dominance of green and blue-green algae. Decrease in the index of species diversity of vegetation due to intensive growth of monodominant groups, higher mean values of some hydrochemical parameters were observed in the water body with a higher degree of anthropogenic load. Bioindication analysis of algae list established dominance of benthic and planktonic species, indifferent in relation to temperature, pH and salinity-standing and flowing forms in water plankton. There was an increase of saprobic indices in both water bodies from spring to summer. Saprobic indices demonstrated that both water bodies belong to β-mezosaprobic zone, but the index was higher in Sokolovskyi pond. To conclude, the analysis of the data proves higher saprobic indices in Sokolovskiy pond as compared to the pond in the arboretum park, monodominance of algae groups testifies to the more profound human impact on the former water body due to its use in fisheries management. The results of the research can be used for monitoring freshwater ecosystems in urban areas.