The Structure of Communities of Hydrobionts in the Eastern Compartment of the Proletarskoe Reservoir (Don River Basin) under Conditions of Different Water Mineralization

In October 2022, the hydrological and hydrochemical parameters and structural characteristics of phyto-, zooplankton, and macrozoobenthos were studied in the western part of the eastern compartment of the Proletarskoe Reservoir, which has a specific thermohaline structure. In the water area under investigation, three regions were identified based on water mineralization values (from 1.1 to 81 g/L): eastern, lake (highly mineralized up to 81 g/L); central (mixing zone); and western (fresh). Among aquatic organisms, euryhaline and halophilic species predominated. In the conditions of a mineralization wide range in these areas, differences in the structure of communities and their quantitative indicators were noted, which are associated with the presence of an unstable lateral gradient of water mineralization, depending on the strength, direction of the wind, and amount of fresh water entering through the Novo-Manychskaya Dam.