Ecosystem and human health assessment to define environmental management strategies: the case of long-term human impacts on an Arctic lake / Moiseenko T. I., Gashkina N. A., Voinov A. A. [et al.] // The Science of the Total Environment. - 2006. - Т. 369, № 1-3. - С. 1-20.

8 TI. Moiseenko et al. /Science o f the Total Environment 369 (2006) 1-20 Table 4 Whitefish disease, % from number of the surveyed individuals (n) in Lake Imandra in various years Main symptoms of fish diseases 1981 n = 788 1986 n =721 1991 n =453 1996 n =462 2003 n = 235 Nephrocalcitoses 52 47 45 14 - Fibroelastos 48 53 55 48 39 Lipoid degeneration of 100 89 78 48 39 liver and cirrhosis Anomalies of gonad 34 27 8 - - structure Scoliosis and 6 4 2 - - osteoporosis (see Table 3 ). In 2003 the total biomass of phytoplank­ ton decreased, but a more uniform distribution was observed unlike the period of high pollution. In 1998 and 2003 the number of species in zooplankton community decreased (up to 70,000 spec/m3); biomass also decreased. Certain zooplankton species that were usual in the lake before, but missing during the period of maximal pollution, were again found, such as the valuable forage crustacean Holopedium gibberum, Daphnia sp., L. Kindtii. However the most vulnerable to pollution Leptodora kindtii, Polyphemus pediculus, Eudiaptomus graciloides, and Heterocope appendicu- lata still can be found only in small quantities. Rotiferan Bipalpus hudsoni, Kellicottia longispina, Notholca sp. were still predominant. Data gathered in 1998 indicate that in Bol’shaya Imandra the conditions for benthic organisms were still quite extreme (Iliaschuk, 2002a) . Sediments of the lake have accumulated large amounts of metals and organic material, making it hard for the benthic communities to come back. Benthic biocenoses are still characterized by low values of biodiversity index (0.95-1.05 bit/ind). Here still most predominant are the Oligochaetae class, T. tubifex and L. hoffmeisteri (Iliaschuk, 2002a) . At the same time, in recent years in the profundal zone the maximal abundance of amphipod M. affinis has sharply increased. In comparison with 1968 it has almost doubled: from 36 up to 60%; at the same time the influence of this crustacean on the Chiromonidae family has also increased, which is also an evidence of the on­ going eutrophication (Iliyaschuk, 2002b) . These results correspond to data from Marzolf (1965). The amount of Arctic char and salmon trout are still low, and still in the shallow Bays there are high numbers of minnows. Note that during the period of economic crisis unorganized fishing (poaching) was on the rise. This, together with eutrophication, could substantially affect the structure of fish communities, in particular, the whitefish population, which forage base has increased. That is why it is difficult to determine the main factor of Fig. 2. Long term results for Ni and Cu accumulation in whitefish organs and tissues.