Sandimirov S.S. Catalogue of lakes in the Russian, Finnish and Norwegian Border Area. Finland, Jyvaskyla: Kopijyva Oy, 2008.

3.4.2. Lake bottom sediments Fig. 70. Vertical distribution of the concentrations of Ni, Cu, As, Cd and Pb (цд/д, dry weight) in the sediment core from Lake Meiialompolo. Table 46. The organic matter contents (LOI, %) and heavy metal concentrations (цд/д, dry weight) in the surface (0-1 cm) and pre­ industrial (28-30 cm) sediment layers. Cfand Cdrefer to the contamination factor and degree of contamination values, respectively. The sediments in Lake Meiialompolo are characterized by organic matter contents (LOI %) in the uppermost 1 cm layer of more than 36% (Table 46). Although the lake is located at a distance of 54 km from the “Pechenganickel” smelter, emissions from the smelter do have an effect on pollution in the lake; in the uppermost 10 cm sedi­ ment layer there is a clear gradient in the Ni and Cu concentrations (Fig. 70), as well as of Co and Zn (Table 46). The lake is also subjected to airborne pollution by chalcophile elements (Pb, As and Cd). The uppermost 10 cm sediment layer has elevated concen­ trations of these elements (Fig. 70): the maximum concentrations of Pb and Cd occur at depths of 3-4 and 4-5 cm, respectively. The contamination factor values for these elements range from 1.1 to 4.2 (Table 46), i.e. the values correspond to moderate and considerable contamination. Pb has the highest Cfvalue. The degree of contamination value (17.2) for this lake corresponds to considerable contamination. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As c. Meiialompolo 0-1 36.68 90 60 140 7 0.41 37.0 4.2 28-30 31.31 43 17 86 5 0.37 8.9 1.3 c, 2.1 3.5 1.6 1.4 1.1 4.2 3.2 17.2 3.4.3. Hydrobiological studies Ichthyofauna. Studies on the fish community in Lake Meiialompolo were conducted in 2005. The ichthyofauna of the lake consists of seven species belonging to six fish fami­ 126 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea