For 8 years (2011–2018) macrozoobenthos samples were taken at the permanent stations in the reservoir-cooler of Balakovo NPP. Sampling stations were located in a highly heated part of the reservoir-cooler of the Balakovo NPP, and poorly heated part, in the adjacent water area of the Saratov reservoir. Differences were revealed: species richness and diversity; numbers and biomass; saprobity indices of the areas of these reservoirs; a positive or negative trend of long-term dynamics of the studied indicators macrozoobenthos.
