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

The low micronutrient concentra­ tions of the water entering the water body reflect the low level of chemical weathering of the minerals present in the watershed area. Although the water­ shed of Lake Njasjukkajarvi is relatively distant from the Pechenganikel smelter (20 km), it is subjected to anthropogenic impacts.The main pollutants are sulphur compounds and heavy metals (Ni, Cu, Co etc.) In spite of the fact that emis­ sions from the smelter have been re­ duced to approximately one third of the peak levels in the late 1970s, the deposi­ tion of pollutants still has an impact on the water body. The average Cu and Ni concentrations are 3.8 |ig/l and 12 |_ig/l, respectively 1.8.2. Lake bottom sediments The sediments of Lake Njasjukkajarvi have relatively low organic matter contents: the LOI value in the surface 1 cm layer is less than 20% (Table 8). The lake is located at a distance of 20 km from the smelter, and is subjected to airborne pollution from the smelter that primarily consists of heavy metals (Ni, Cu, Co) and chalcophile elements (mainly Cd, As and Hg). The contamination factor values for these toxic elements range from 1.6 to 3.9 (Table 8), i.e. the values correspond to moderate and consider­ able contamination. Copper has the highest Cfvalue. The degree of contamination value (16.5) for this lake corresponds to considerable contamination. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As Hg cd Njasjukkajarvi 0-1 14-15 18.23 8.34 131 33 141 41 101 101 37.0 16.3 0.11 0.07 3.0 3.2 7.26 4.57 0.023 0.014 cf 3.9 3.4 1.0 2.3 1.7 0.9 1.6 1.7 16.5 1.8.3. Hydrobiological studies No direct hydrobiological investigations have been carried out in this lake. The fish fauna in Lake Njasjukkajarvi is characterised by species such as trout ( Salmo trutta ), whitefish ( C oregonu s lavaretus), grayling ( Thumallus thumallus), pike (Esox lucius), perch ( Perea £uviatilis), burbot ( Lota lota), minnow ( Phoxinus phoxinus ) and nine- spine stickleback ( Pungitius pungitius). Watercolour, deg. 15 14-15 NH4, |ig/l 7 4-10 N03, |ag/l z 7-7 Total N, цд/І 102 91-114 P04, цд/І 1 1-1 Total P, цд/І 4 4-4 Fe, цд/І 31 24-39 Cu, цд/І M 3.4-4.3 Ni, цд/І 12.2 12.2-12.2 Al, цд/І 21 25-28 Pb, цд/І 0.17 0.15-0.20 Table 8. The organic matter con­ tents (LOI, % ) and heavy metal concentrations (pg/g, dry weight) in the surface (0-1cm) and pre-industrial (14-15 cm) sediment layers. Cfand Cdare contamination factor and degree of contamination values, respectively. Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea 31