[in Russian with English abstract: ] The paper summarizes the data obtained by analyzing the reaction of the coastal epilithic lichen cover tothe chemical parameters of water in reservoirs of different types and uses. The study was carried out on the shores of freshwater bodies (Lake Onega, Lake Ladoga, Lososinka, Suna rivers) with different anthropogenic pressures in the Republicof Karelia. At each place of study, the lichen cover was described at the survey sites (frame 10 x 20 cm) along the transectand water samples were taken for chemical analysis. The aim of the work is to identify indicators of the coastal epilithic lichen cover to indicate the quality of the aquatic environment and assess the state of coastal ecosystems. The lichen flora ofthe surveyed coasts of fresh water bodies has 53 species, the highest species diversity of lichens is characterized by placeswithout obvious sources of pollution – the Kivach reserve (29 species), the shores of Lake Ladoga (27 species) and the Botanical Garden of PetrSU (16 species), and in urban conditions ( Petrozavodsk), a large settlement (Yanishpole) and nearthe pulp and paper industry (Kondopoga), the number of lichen species is much lower (8, 5 and 4). Regression analysisshowed the dependence of the number of lichen species on the registration site on the concentration of phosphorus compounds in water (p