Zooplankton as indicator of lake Kamennoe ecosystem condition

Research results of zooplankton studies of the Lake Kamennoe are presented in the article. The research was carried out in the frames of an integrated program of biological monitoring of water bodies of the Republic of Karelia in 2010-2012. The lake is located in the specially protected area of Nature Reserve "Kostomukshskiy". Conducted studies have shown that the zooplankton community of the Lake Kamennoe is represented by conventional species of Karelian water bodies with wide geographic distribution. Altogether, 41 species of planktonic rotifers and crustaceans have been registered. Among the dominant species are Asplanchna priodonta Gosse, Holopedium gibberum Zaddach, Daphnia cristata Sars, Bosmina coregoni Baird, Eudiaptomus gracilis Sars. According to the level of quantitative development of planktonic fauna, the Lake Kamennoe belongs to the oligotrophic type with an average biomass up to 1 g/cub.m. By saprobity index value, which is calculated by the indicator of organisms' biomass, the Lake Kamennoe can be attributed to oligosaprobic class of water bodies (2nd quality class - pure natural water). Comparison of the results with the studies conducted in the 70s and 90s of the twentieth century confirms that the lake's ecosystem retains its natural state and does not experience additional human impact.