ASSESSMENT OF THE ECOLOGICAL STATE OF WATERS BY THE SPECIES COMPOSITION OF ZOOPLANKTON AND PHYTOPLANKTON

Abstract

Presented the results of studies of macrophytes, zooplankton and phytoplankton and the chemical composition of water polluted by sewage from a livestock enterprise and a conditionally clean pond. It was established that changes in the chemical composition of water after entering the reservoir of wastewater from a livestock enterprise due to an increase in the concentration of mineral and ammonium nitrogen, sodium ions, a decrease in the content of calcium and magnesium ions and hydrogen carbonate ions, at constant values of the pH indicator, total mineralization, potas-sium ions, chlorides and sulfates. Compared to a conditionally clean reservoir, it became polluted with sewage and was characterized by the intensive development of higher aquatic plants, a smaller number of zooplankton species, and its abundance and biomass underwent changes due to a decrease in the number of rotifers (Rotatoria) and an increase in the number of spiny (Sladocera) and copepods (Copepoda) crustaceans. Studies of the species composi-tion, number and biomass of phytoplankton in a pond polluted with wastewater from a livestock enterprise estab-lished the predominance of euglena algae over other species in the reservoir, a significant increase in the number of blue-green (Cyanophyta) and diatom (Bacillariophyta) algae in biomass, the presence of small-celled flagellates with department of cryptophytic and bacterial-fungal accumulations, in contrast to a conditionally clean water body. A conclusion was drawn on the expediency of using the species composition of phytoplankton and zooplankton, as well as individual indicators of the chemical composition of water as criteria for assessing the ecological state of ponds located in the area of activity of livestock enterprises when polluted by sewage.