Ecological and sanitary condition of the Voronezh water reservoir under “blooming” conditions based on materials from 2016–2022

The aim. Study of the ecological state of the Voronezh reservoir under conditions of “blooming” of water by cyanobacteria. Materials and Methods. EEvaluating water quality data of hydrochemical analysis, assessment of suspended solids distribution and temperature in the water area, materials of hydrobiological study (phytoplankton), microcystin content in water have been taken into account. Results and Discussion. The direction of anthropogenic changes occurring in the ecological state of the reservoir has been traced for 2016–2022. The irreversible effects associated with water quality deterioration were clearly evident under the influence of abnormally high summer air temperatures in 2010–2012, accompanied by the massive development of water “blooms”. This has had irreversible consequences, as an ecological regression has finally taken shape in most of the water area. At present, including 2022, there is a prolonged summer-autumn “bloom” of waters, the associated with it an increase in the volume of organic matter, formation of aquatic toxicity due to cyanotoxins produced by cyanobacteria. For this period we have evaluated the distribution of the relative content of suspended solids and water temperature. Conclusion. The prognosis ofwater quality transformation is unfavourable, as it is accompanied by a directed ecologicalregression of the reservoir ecosystem, and is emphasized by intensive “blooming” of waters. For their rehabilitation, a biotechnological method of algolisation can be recommended.