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

Environmental pollution problems in the far north of Europe The region has always been famous for its large number of lakes and rivers, with pure fresh water populated by valuable species of fish and invertebrates. The water resources in the north play an important role in the life of the indigenous people and the econ­ omy of the whole region. However, major changes at the global scale during the past century have set serious threats on the quality of northern water bodies. The intensive development of industrial production during the 20thcentury has resulted in the spread of environmental pollutants throughout most parts of the globe. Pollutants that can accumulate and be cycled within ecosystems over a long period of time constitute a considerable threat to the environment. The Murmansk region is one of the most industrialized areas in the Arctic. Long-range, trans-border pollution, carried by air masses from industrial areas in Europe, America and Asia, and the active develop­ ment of local sources of pollution (mining and ore processing, metallurgical industry, power plants, transport etc.) has brought about a sharp increase in the discharge and deposition of airborne pollutants directly into surface waters, as well as throughout the catchment areas. Pollution accumulates specifically in the water bodies Most of the pollutants deposited in the catchment areas finally end up in the aquatic ecosystems; even though they are partly incorporated into the biogeochemical cycles of terrestrial ecosystems, this usually only means a relatively short time delay. Heavy metal contamination Heavy metals belong to the most toxic group of pollutants. They pass into the envi­ ronment from a wide range of sources, and they can accumulate and be cycled within ecosystems for a long period of time, resulting in a constant increase in their concen­ trations in natural environments, and have severe toxic effects on biological systems at different trophic levels. Heavy metals have always been present at varying concentrations in natural envi­ ronments. They occur in the bedrock, soil, natural water, and in plants and animals. The role of these elements in the complex interactions between the biota and environment is relatively unclear. On the one hand, with rare exceptions, they are essential at low concentrations for the growth and development of all living organisms. A deficit of a specific metal may, for instance, result in functional disturbances in an organism. On the other hand, they are usually highly toxic at elevated concentrations. Mercury (Hg) and cadmium (Cd) play the most important role in pollution of the Arctic region and they constitute a major threat to ecosystems in the region. They do not have any known biological function, but they can be bioaccumulated and are toxic even in very small amounts. They are present in big quantities even in the regions, dis­ tant from anthropogenic sources. The next metal of considerable concern is lead (Pb), which is also highly toxic. Other metals, such as copper (Cu) and nickel (Ni), have a relatively more restricted distribution and are concentrated in the impact areas of the metallurgical plants. Acidification of water bodies Together with heavy metal pollution, the acidification of surface water and catchment areas is intensifying and it has become one of the most urgent problems in recent dec­ Catalogue ofLakes in the Russian, Finnish and Norwegian BorderArea