Integrated Assessment of the Ecotoxicological Status of Reservoirs in the Middle and Lower Volga Using Biodiagnostics and the Analysis of Heavy Metals in Bottom Sediments

A comprehensive assessment of the ecotoxicological status of reservoirs of the Middle and Lower Volga has been performed using biodiagnostics (biomarking and biotesting) and an analysis of the content of heavy metals in bottom sediments. The spatial variability of the content of heavy metals in bottom sediments and of the values of biomarkers of the status of oxidative stress in the liver of bream from different reservoirs is established. The toxicity of bottom sediments is determined. According to the results of the study, the reservoirs may be arranged in the following sequence according to the degree of deterioration of the ecotoxicological status: Gorky > Volgograd = Saratov > Kuibyshev > Cheboksary. The Rybinsk Reservoir in the area of station 1 (Koprino) can be taken as a background area in terms of anthropogenic load.