Response of algal communities to anthropogenic changes in mineralization

A relatively new type of impact of human activities on lake-river system has resulted from mining operations in the Kostomuksha iron deposit, Karelia, NW Russia. Lake Kostumus was isolated by a dam and has since acted as a waste accumulator for ore-dressing production. The total mineral content of the water has reached 400 mg l-1. Comparative analysis of the structural organization and functioning of phytoperiphyton and phytoplankton in the Kenti lake-river system and subject to anthropogenic load resulting from urbanization is presented. The algal communities influenced by mineralized mining mill wastes were analysed in terms of species richness, species diversity, species ecology values, biomass and chlorophyll a concentration. When the anthropogenic load is minimized, the natural structure of algal assemblages quickly restores. This is most typical of lake-river systems with alternations of lakes and rivers, rapids and pools, playing the role of natural water treatment facilities. The possibility of using algal assemblages as an indicator of the ecological state of lake-river ecosystems is analysed.