THE CURRENT STATE OF PLANKTON COMMUNITIES OF THE NIKOLSKY ESTUARY OF THE SEVERNAYA DVINA RIVER IN 2022

The work is part of the environmental monitoring of the Nikolskaya estuary. Severnaya Dvina, carried out in 2022, with the aim of comprehensive research of aquatic biological resources and their environment. Information was obtained on the species diversity and structure of plankton communities of the studied object belonging to the drainage basin of the Severnaya Dvina River. The taxonomic composition of phytoplankton and zooplankton in the navigation period of 2022 is shown. Species diversity was assessed using the Shannon index, based on the relative abundance of species, the Menhinik, index, which determines species richness, the average abundance and biomass of phytoplankton of the Nikolsky Estuary were determined. The Pantle-Bukka saprobity index was calculated to assess the pollution of natural waters. According to observations, 53 algae taxa with a rank below the genus and 21 zooplankton organisms have been registered. It was found that the basis of algoflora was diatoms. Copepoda copepods formed the basis of the zooplankton community. New data on the state of phytoplankton and zooplankton communities can serve as an informational and methodological basis for the development of environmental monitoring programs for aquatic ecosystems in the region.