Scientific publications

The results of bioassay and physicochemical analysis of bottom sediments from large water bodies in Northwestern Russia are presented. The water bodies under consideration include Lake Onega, Vygozerskoe Reservoir, and freshwater part of the Neva Estuary (the Eastern Gulf of Finland), which are locally subject to eutrophication and toxic pollution. The potential toxicity of bottom sediments, evaluated by the survival rate of two crustacean species (Gmelinoides fasciatus and Ceriodaphnia affinis) in 7-day tests, varied from high to low values, characterizing 5 quality classes: high, good, moderate, poor, and heavy, with appropriate degrees of toxic pollution from no to very high pollution. Bad zones were identified in the Kondopoga and Petrozavodsk bays of Onega Lake, the northern and southern parts of the Vygozerskoe Reservoir, and the southern part of the Neva Bay near the dam. Bottom sediments were found to have high quality in the open central areas of Lake Onega and the Vygozerskoe Reservoir and in the western part of Neva Estuary.