Vandysh O. Assessment of copper-nickel industry impact on a subarctic lake ecosystem. The Science of the Total Environment. 2003, T. 306, № 1-3, c. 78-83

80 A. Lukin et al. / The Science of the Total Environment 306 (2003) 73-83 Cu in liver 120 и 100 - О 80 40 20 - 0 -I------------------- ■------------------- ,------------------- ,--------------------,--------------------,------------------- ,------------------- , 0 0.5 1 1.5 2 2.5 3 3.5 In Cf Fig. 7. Dependence of Cu concentrations in fish liver (mg g -1 dry wt.) on the natural log of contamination factor for Ni in sediments (Cf). Values of Cf increased with proximity to the smelter effluent. in the liver, and the lowest in the muscles. No direct correlation was found between Cu accumu­ lation in fish and the Cf for Cu (Fig. 7). It should be noted that in Lake Kuetsjarvi, close to the source of pollution, Cu concentrations in fish were lower or equal to the control or to the values found in fish captured from more remote areas. Generally, the concentration of Cu was below the control levels despite the fact that the concentration in the sediments exceeded the background level. Zn concentrations in the organs and tissues of the fish examined were highly variable. This metal was accumulated in higher concentrations com­ pared to the others, despite its relatively low concentration in the water. However, Zn concen­ tration in the liver was lower than in the control fish. Zn concentrations in liver declined with increasing ln Cf and were lowest at the sample sites nearest the source of pollution (Fig. 8). The concentrations of Zn in gills and kidneys of white- fish captured near the pollution source were higher than in the control fish, but lower than in fish from the upper reaches of the Pasvik River (Fig. 8). The lowest Zn concentrations were found in the muscles. 4. Discussion Deeper sediments, according to earlier estimated sedimentation rates (Rognerud et al., 1993), were deposited more than two centuries ago, i.e. before the industrial development of the Kola Peninsula. Background concentrations of heavy metals in sediment samples taken from the deepest parts of the cores (usually more than 20 cm) of Lake Kuetsjarvi are almost the same as the values (Table 1) typical for the Kola Peninsula (Dauvalter, 1994, 1997). Atmospheric emissions of Ni, Cu, Co, Zn, Cd and Hg from the smelters, as well as waste water discharges from tailings dumps and mines are likely to be the main sources for the increased concentrations in the water column and recent lake sediments (Moiseenko et al., 1994, 1995; Dauval­ ter, 1992, 1994, 1997). The highest sediment contamination factors were noted for Ni, Cu, Hg and Co (Table 1), which had very high Cf values according to Hakanson (1980) classification. Other heavy metals (Zn, Cd, Pb and Mn) had moderate Cf values according to Hakanson’s classification. The calculated sedimentation rate is estimated at approximately 3 mm year-1, which coincides with the sedimentation rate suggested above for Lake Kuetsjarvi (Dauvalter, 1994). Comparison of the total phytoplankton volume in Lake Kuetsjarvi with other lakes of the region demonstrates its increased productivity. Average annual values of the total volume change in a wide range from 2000 up to 5000 mm3 m -3, whereas these parameters in other lakes of the region, which are not exposed to anthropogenic loadings, are 200-1000 mm3 m -3 . Extraordinarily high levels were due to mass development of the diatom species Fragilaria capucina (6232 mm3 m -3) and Asterionella formosa (4057 mm3 m -3) (Moiseen- Zn in liver 0 1 2 3 4 In Cf Fig. 8. Dependence of Zn concentrations in fish liver (mg -1g dry wt.) on the natural log of contamination factor for Ni in sediments (Cf). Values of Cf increased with proximity to the smelter effluent.