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

Fig. 87. Mercury concentrations in the muscle ofsparsely rakered whitefish in the studied lakes. Mercury. The Hg concentrations in whitefish muscle in the Finnish lakes (Meiialom­ polo, Aittojarvi, Kantojarvi and Suovaselkajarvi lakes) were the highest (Fig. 87). Concentration of Hg in muscle (цд/д dry weight) 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 0,0 - 0,2 : "Kin I LSJ р*п —г—o ; j L™ rX ^? T LflJ 4*0*" £ £ £ .а а Й с< £ £ 2, --i» .-=» :ro CU :=> The Cu, Ni, Cd and Pb concentra­ tions in fish muscle do not exceed the established standard values. However, the Hg concentrations in perch (Lake Kochejaur) and pike (lakes Kochejaur, Aittojarvi and Kantojarvi) muscle are higher than the maximum permissi­ ble concentration. Overall, the metal concentrations of (pg/g dry weight) in other fish organs are much higher than those in the muscles. Further assessment and monitoring of the small lake ecosystems in the region are required. This should primarily be based on the characteristics of the whitefish, perch and pike populations and on parameters of the phyto-, zooplankton and benthic communities. In some lakes populated by trout and char these species are more reliable as quality indicators of the aquatic ecosystems. Metal concentrations in fish reflect the level of anthropogenic pollution in the water bodies. These indices can therefore be employed in assessing the impact and extent of airborne industrial pollution. The permanent monitoring of ichthyofauna is needed to control the air borne pollution of water bodies. 140 Catalogue o f Lakes in the Russian, Finnish and Norwegian Border Area