Characteristics of the Vertical Distribution of Chlorophyll in Reservoirs of the Middle and Lower Volga

The results of the study on the vertical distribution of abiotic characteristics and chlorophyll (Chl a ) in the Gorky, Cheboksary, Kuibyshev, Saratov, and Volgograd reservoirs in the summer of 2021 are presented. The content of Chl a varied from 5.5–8.5 to >100 μg/L in the Middle Volga to 22 and 47 μg/L in the Lower Volga, and was typical for the summer maximum of phytoplankton in the Volga reservoirs. In the absence of density stratification for most stations, a uniform Chl a distribution in the water column was revealed with variation coefficients of no more than 20%.