Taxonomic composition and abundance of macrozoobenthos in the Rybinsk Reservoir at the beginning of the 21st century

The structure of macrozoobenthos has been studied in the deep-water part of the Rybinsk Reservoir. A total of 73 species of bottom macroinvertebrates have been recorded, the majority of which are mollusks, oligochaetes, and chironomids. The macrozoobenthos on gray silts of channel parts of the reservoir was the richest in taxonomic composition and quantitative abundance. The maximum number of species has been recorded in the former mouth of the Mologa River, and the highest abundance of macrozoobenthos has been recorded near the village of Breitovo in June. Most of the macrozoobenthos is made up of oligochaetes and chironomid larvae; midge larvae dominate by biomass. Compared to the end of the 20th century, changes in the taxonomic composition and in dominating species of macrozoobenthos are observed.