Monitoring of hydrochemical parameters of Lake Pit’evoe on Bolshoy Solovetsky Island

We conducted five-year hydrological studies (from 2020 to 2024) of a small freshwater lake on Bolshoy Solovetsky Island during the summer low water period, obtained hydrochemical data and compiled a bathymetric mapparameters of . This glaciotectonic body of water was classified as a small deep lake receiving waters of the western lake-canal system. It does not experience direct anthropogenic impact, with the exception of recreational load. Air temperature and precipitation fluctuations led to changes in temperature and water level in the water body studied . The combination of these variations influenced the hydrochemical parameters. Color, electrical conductivity, increase of dissolved iron and pH, lower mineralization (sum of main ions) largely depended on the amount of precipitation. Water temperature affected the concentration of oxygen and anoxic conditions were created in the bottom layers of the lake. The occurrence of anaerobic processes in the bottom layers of the lake was accompanied by an increase in the products of organic matter destruction, in particular, hydrocarbonates. At the same time, no increase in the content of hydrogen sulfide was noted, its concentrations did not exceed 5 μg/l over the period of research. The results obtained indicate the need to conduct annual monitoring of drinking water sources, even though present fluctuations in the hydrochemical indicators are mainly associated with climatic changes.