Impact of airborne pollution on the drainage area of subarctic lakes and fish

Within the period from 1989 to 1993, the impact of heavy metals and acid ox ides on lakes, more than 100 km distant from the nearest source of pollutio n (enterprises of the copper-nickel industry), has been investigated. On th e basis of complex investigations (chemical composition of snowpack and lak e sediments, stale of fish organisms and populations), it was discovered th at there is intensive precipitation of heavy metals and acid oxides within the catchment of the lake Kochejavr. The catchment is characterized by a na tural buffer capacity to neutralize acid precipitation. Active accumulation of heavy metals is observed in lake sediments. Metal accumulation causes s ubtoxic effects on the lake fish. The levels of precipitation of nickel and copper of 0.9 mg/m(2) per year over long periods was found to be dangerous for biological systems of freshwater catchments. (C) 2000 Elsevier Science Ltd. All rights reserved.