HEAVY-METAL CONTAMINATION IN FRESH-WATER FISH FROM THE BORDER REGION BETWEEN NORWAY AND RUSSIA

The contents of Cd, Cu, Cr, Hg, Ni and Zn in muscle, liver and gills w ere studied in whitefish, perch, pike, brown trout, burbot and vendace from three lake localities in a watercourse in the border region betw een Norway and Russia, in the vicinity of mining activity and several metallurgic smelters. The contents of Cd and Ni in fish tissue increas ed with increasing proximity to the smelters, whereas the other elemen ts showed similar concentrations at the three localities. The recorded heavy metal concentrations appeared to be within the ranges reported for fish from other metal-contaminated lakes, and higher than comparab le observations from unpolluted systems. The heavy metal concentration s were usually lowest in muscle and highest in the liver or the gills. Significant differences in metal concentration levels were found betw een different fish species, but Hg was the only metal where these spec ies differences were possibly related to biomagnification. For the oth er elements, the concentrations generally appeared to be inversely rel ated to the trophic level of the fish species. (C) 1997 Elsevier Scien ce B.V.