Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 6

Like most of the northern rivers, the Vychegda river, the second largest water system of the Komi Republic and the main tributary of the Northern Dvina river, is experienced intense anthropogenic load. Agricultural, domestic and industrial, at a greater extent, waste waters are currently the main polluting sources of river waters. The largest pulp and paper enterprise in Russia, Mondi Syktyvkar JSC, is located on the Vychegda riverbanks among the numerous enterprises operating here. The composition and structure of the zooplankton communities were investigated in the Vychegda river area, where effect of waste waters from the pulp and paper enterprise is observed. The research aim is to find out there is a negative impact of the conditionally treated waste waters on the aquatic biota. As a result, a rich species composition and quantitative development of zooplankton communities were established for the investigated river area. Rotifera was the dominant group on species abundance, number and biomass. This is characteristic feature of zooplankton communities in the watercourse as a whole. The indicator species of waters with a high level of pollution were registered both at points located in the area of waste waters influence and at the background plots of the river. The species which are not peculiar to the natural waters of the river were found in points of waste water discharge. The dominant complexes are represented by 9-15 species лучше. Their composition differs at background, waste waters and downstream points. According to the state of zooplankton communities, the river waters in the studied area are conditionally clean, except the points located downstream of waste waters discharge, where they are qualified as eutrophic.