On hydrological and hydrochemical features of lakes of the Bolshezemelskaya tundra

Researches of hydrological and hydrochemical features of lakes of four river watersheds of the Bolshezemelskaya Tundra (Ortina, Neruta, Kolva and More-U) have been carried out. The oil and gas exploration and production are intensively conducted on the Bolshezemelskaya Tundra territory. According to the origin of hollows three types of lakes have been distinguished - glacial, flood-land and thermokarst. Thermokarst lakes are characterized by the minimal average values of water pH, mineralization and contents of the basic ions (except for Na+ and Сl-), and also the maximal average concentration of nutrients, organic material and almost all microelements. Contents of Fe, Cu, Mn, Al, and oil hydrocarbons in water of practically all the investigated lakes have exceeded values of maximum permissible fishery limits, that is basically connected with the development of the oil-and-gas industry in this region.