Catalogue of Lakes in the Russian, Finnish and Norwegian Border Area = [Каталог озер в приграничном районе России, Финляндии и Норвегии] / Nikolay A. Kashulin, Vladimir A. Dauvalter, Sergey S. Sandimirov etc. - Apatity : Institute of the North Industrial Ecology Problems KSC RAS etc., 2008.

Water colour, deg. 19 10-32 nh 4, pg/1 7 1-22 N03, цд/І 16 1-98 Total N, ng/l 192 100-597 P04, цд/І 1 1-2 Total P, цд/І 4 2-6 Fe, ng/1 123 5-1571 covered with a thick layer of silt, com prising undecomposed zooplankton de bris and organic matter. This feature is of primary importance for the feeding of ichthyofauna. The conditions for the growth of organisms are obviously high ly favourable. Due to the fact that most of the lake is not deep, the circulation of mineral nutrients in the water is faster in the summer; this also increases the production capacity of the water body. During high water periods and high precipitation episodes in the autumn, the concentrations of species of mineral nutrients (P 0 43_ and N 0 3') that deter mine the lake productivity are low. The watershed of Lake Shuonijaur is subjected to the impact of pollutants emitted by the “Pechenganikel” smelter. The main pollutants are sulphur com pounds and heavy metals (Ni, Cu etc.). Maximum concentrations of Cu (up to 7.5 pg/1) and Ni (17 pg/1) were recorded in the water in the 1990s. At the present time, due to the reduction in the airborne pollution load, higher Cu (up to 11 pg/1) concen trations occur during the flood period when the snow melts in the watershed, and of Ni (up to 182 pg/1) during flood periods and the autumn low-water periods. Cu, ng/l 47 2.0-11.0 7.4 Ni, ng/l 4.7-17.0 40 Al, цд/І 14-194 0.22 Pb, ng/l 0.10-0.56 1.18.2. Lake bottom sediments Table 20. The organic matter contents (LOI, %) and heavy metal concentra tions (цд/д, dry weight) in the surface (0-1 cm) and pre-industrial (14-15 cm) sediment layers. Cf and Cdare contamina tion factor and degree of contamination values, respectively. The sediments of Lake Shuonijaur have somewhat lower organic matter contents: the LOI value in the uppermost 1 cm layer is slightly less than 30% (Table 20). The lake is located at a distance of 20 km from the Pechenganikel smelter, and is subjected to airborne pollution by heavy metals (Ni, Cu, Co) and chalcophile elements (Pb, As, Cd and Hg).The top 3-4 cm layer of the lake sediments is the most polluted by Ni, Cu and Co. Pollution by chalcophile elements started earlier: these elements are present in the top 6-7 cm layer especially (Fig. 25). Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As Hg Cd Shuonijaur 0-1 29.76 100 117 63 7.8 0.47 12.1 2.03 0.040 14-15 21.97 14 13 47 1.7 0.06 0.8 0.74 0.013 cf 7.3 9.3 1.3 4.6 8.5 14.9 2.7 3.1 51.7 62 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea