Global Change in Respect to Tendency to Acidification of Subarctic Mountain Lakes

Abstract

The Kola Peninsula mountain lakes reflect a real situation not only of the local polluted airborne transfer but also polluted transborder emissions from Europe to Arctic. Despite of two monitoring mountain lakes (the Chuna and Chibiny lakes) are close to smelters of the Severonickel Company, local emissions very slightly affect the mountain lakes, because heavily polluted air masses do not rise high altitude. Sulphur depositions on the Chuna and Chibiny lakes catchments are 0.4 and 0.6 g/cm², respectively, in comparison with area at the foot of the mountain, where the deposition is 1.0–1.5 g/cm². The water quality of the lakes is consistent with an average value for the region: SO ^2-₄ <80 μeq/l, Ni<l μg/l. In the Chibiny lake there is observed a moderate water buffer capacity. The analysis of sediments showed, that heavy metal concentrations exceeded in the upper of 4–5 cm layers of the Chuna lake sediments are accounted by local atmospheric emissions of smelters (as regards Ni and Cu), and general increase of Pb contamination in the atmosphere of the northern hemisphere. Diatom investigations in the sediment cores of the lakes have ascertained a tendency to acidification process. In the originally weakly acidified and sensitive Chuna lake the pH reconstructed has dropped from 6.7 to 6.2. Diatoms from the Chuna lake reflect also the toxic load- in the upper layers there occur the ugly pathological forms.