Sandimirov S. Specific Features of Accumulation of Cu, Ni, Zn, Cd and Hg in Two Whitefish Coregonus lavaretus (L.). Morphs Inhabiting the Inari-Pasvik Lacustrine-Riverine System. Inland Water Biology. 2011, Vol. 4, №, p. 383-392.

SPECIFIC FEATURES OF ACCUMULATION OF Cu, Ni, Zn, Cd, AND Hg 391 Fig. 4. Content of Hg in the organs of (A) sparsely rakered and (B) medium-rakered whitefish in the Pasvik Riverbasinwaterbod­ ies. Other legends are the same as in Fig. 2. 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 ♦ 1 ■ 2 _• 3 a 4 %_ 5 Fig. 5. Relation between contents of Cu, Ni, Zn, Cd, and Hg (^g/g) in the indicator organs ofwhitefish and the technogenic load on the studied waterbodies (natural logarithm of Ni concentration in the surface layer of BSs): (a) Cu, Ni, Cd (left Yaxis); (b) Hg (right y axis); (1) Cu (liver), (2) Ni (kidney), (3) Cd (kidney), (4) Zn (gill), (5) Hg (muscles). (x axis) Intensity of load. were found in Lake Kuetsjarvi. The concentrations of Cu, Ni, and Cd in the fish from this lake were highly variable, and the differences in the metal contents between two morphs of whitefish were the most pro ­ nounced: the contents of some HMs were higher in the planktivorous morph than in the sparsely rakered one. It is known that these morphs differ both in terms of preferred habitats and in the intensity and direction of metabolic processes [2, 3, 9]. However in the studied basin, an increase in the share of benthic organisms in the diet of typical planktivorous whitefish and an increase in their occurrence in the profundal zone were noted. Such modifications are related to the competitive relations with nonindigenous species introduced in the Pasvik River (vendace). This species was intentionally introduced to Lake Inari and further spread over the whole river basin. Presumably the changes in the living conditions in combination with the differences in metabolic processes determine the higher levels of HM accumulation in the organism of medium-rakered whitefish. Despite the pronounced gradient pattern of con­ centrations o f priority pollutants, the water chemical parameters are subject to considerable seasonal and spatial variations within the Pasvik River basin, which is especially clear for the elements of global pollution [22]. The characteristics of BS contam ination are more representative indices for assessing the anthro­ pogenic impact in conditions o f gradient load. At the same time, it is necessary to bear in mind that BSs accumulate insoluble forms of metals while the soluble forms and the metals included in the organisms of food items possess the highest biological activity. The con­ centration o f Ni in BS was chosen as a conventional index of the level of technogenic load on a waterbody because Ni is largely a priority pollutant in the region under study that determines the accumulation o f other HMs [1, 22]. The accumulation o f this chemical ele­ ment in a fish’s organism is directly proportional to the anthropogenic load within the studied basin. The accumulations of Cu and Zn by fish demonstrate a more complicated pattern and are determined both by the environmental levels of these elements and by Ni in combination with a set of various environmental factors and the state o f the organism. The processes of Hg accumulation in whitefish muscles demonstrate a reverse Ni-dependence which may reflect their “neg­ ative” interelemental interrelation. CONCLUSIONS The highest levels of HM accumulated in fish were revealed in the 30-km zone near the smelter. Outside this zone, the levels of Ni and Cd decrease sharply. The benthivorous whitefish has the highest body burden o f Ni. Despite the naturally higher HM loads on the organism, their concentrations (Ni, Zn, and Hg) in fish may be lower than in the medium-rakered white- fish, which is determined by the partial switch of this morph to the benthic mode of feeding. The concentra­ tions of chemical elements in the organism of plank­ tivorous whitefish exhibited a clearer gradient depen­ dence on the air-technogenic and direct contam ina­ tion of the Pasvik River waters by Cu, Ni, and Cd. Presumably, the HM load on the benthivorous white- fish is more intense owing to the considerable pollu­ tion of the BSs and near-bottom water layers. In this case the gradient dependence is less pronounced. It INLAND WATER BIOLOGY Vol. 4 No. 3 2011