Changes in the Structure of Macrozoobenthos in the Rybinsk Reservoir under Conditions of Rising Temperature

Abstract

An analysis of the results of long-term observations has demonstrated changes in the species structure and a significant increase in the abundance of macrozoobenthos in the deepwater part of the Rybinsk Reservoir in extremely warm years at the beginning of 21st century. After the anomalously hot summer of 2010, the species richness and diversity decreased to their minimum values. In the following years, a peak in the abundance and biomass of macrozoobenthos, due to the mass development of chironomid larvae (g. Chironomus) and polysaprobic species of oligochaetes, has been observed. Presumably, this peak is determined by the increased rates of eutrophication.