Transformation of Natural Water Bodies as a Standard of the State of Water Ecosystems of Specially Protected and Urbanized Territories

Abstract

Purpose – Transformations of natural reservoirs of the state reserve “Voroninsky” are considered in order to obtain criteria for identifying the direction of anthropogenic changes in the ecological state of surface waters. Materials and methods. When assessing the ecological state of water bodies, methods of calculating the saprobity index and comparing the taxonomic composition of the phytoplankton community were used. Results and discussion. Global climatic changes are manifested in the shallowing and overgrowing of water bodies, in an increase in the volume of organic matter formed in bottom sediments. The formation of new biotopes is taking place, and the taxonomic and ecological composition of communities of microalgae and cyanobacteria is transformed accordingly. The influence of air temperature anomalies in 2010-2012 manifested itself in the invasion of the reserve's lakes and the mass development of thermophilic cyanobacteria species alien to the region. There is no “blooming” of water bodies due to the equilibrium state of the processes of formation, accumulation and mineralization of organic matter. The Voronezh Reservoir is a water body located in an anthropogenically loaded territory. “Bloom” of waters, represented by cyanobacteria of the genus Microcystis (Ku & & tz. ) Elenk. The temperature stress of 2010-2012 found a response in the ecological state of the reservoir: the “bloom” of water in 2013-2020 gained a greater areal distribution over the water area, and became more prolonged during the growing season, recorded practically from June to October. The general tendency in the formation of the ecological quality of waters is associated with their widespread pollution, including those caused by the proliferation of cyanobacterial species, which often release cyanotoxins in the process of metabolism. Conclusions. The forecast of transformation of surface water quality is unfavorable and emphasizes the severity of the current ecological situation.