Koroleva I.M. The status of whitefish population from Chuna Lake in the Lapland Biosphere Reserve Russia. International Journal of Environmental Research. 2008, V.2, №2, p. 111-124.

The status o f whitefish population 1949-1950 2000-2001 2000-2001 Fig. 5. Comparative average size-and-weight values of the matured whitefish population □ - Mean, d — ±SE, I - ±SD, o- Outliers, *- Extremes Table 6.The number of non-spawning individuals (% of the number of fish in the age group, n=303) age, yrs non-spawning individuals, % 5+ 34 6+ 36 7+ 55 8+ 40 9+ 50 Compared to kidney and liver, the Cu concentrations in gills were the least (liver>kidney>gills). Nevertheless, the distribution of Cu concentration in gills and kidney exhibited some common trends. The highest Cu concentrations in liver, kidneys and gills of whitefish fell on October (Fig. 8). During the following months the concentrations decreased, which is likely due to the end of the feeding period before spawning and due to work of detoxication mechanisms, which decrease Cu concentrations in the organism. In winter, however, the Cu concentrations in liver increased (Fig. 8). Besides, seasonal dynamics of the Cu concentrations in liver showed considerable variations. The Cu concentrations in liver o f whitefish were the highest in October and January, accounting for 102.80 and 94.92 mkg/g dry weight, respectively (Fig. 8). The mean Cu concentrations in gills and kidneys were more than 10 times less (Fig. 8). It should be noted that the Cu concentrations in water during the year have not practically changed, being equal to 2 mkg/L. The differences in the Cu concentrations in whitefish organs in autumn were often statistically more reliable compared to other months. On the whole, during the year, the differences ofminimum and maximum values of the Cu concentrations in liver, kidneys and gills were statistically reliable (p<0.05). Nickel is one of the major pollutants of aquatic ecosystems of the Kola North, which is discharged by mining enterprises. As a rule, the highest values of Ni concentrations in fish were recorded in kidneys. The concentrations in other organs were lower, being d istribu ted as follows: kidney>gills>liver (Table 7). The Ni concentrations in whitefish gills were at least 4 times less compared to that in kidneys. The highest mean Ni concentrations in kidneys accounted for 6.7 mkg/ g diyweight (Fig. 9). The maximum value accounted for 16.5 mkg/g dryweight in September. Then, after the two-fold reduction ofthe Ni content in October, its concentrations slowly increased till July. In summer, however, the Ni concentration in kidneys of whitefish lowered against that recorded in the beginning of autumn. The metal concentration distribution differed reliably through months — the same as it has been observed for the Ni distribution in gills. During the year, the maximum and minimum values differed reliably only for liver and kidneys (p<0.05). The distribution of heavy metals in whitefish organs was characterized by two peaks of their concentrations, as a rule, twice a year. The peaks o f Cu concentrations fell on autumn-winter and summer periods. The levels of copper concentrations in fish organs show a non-uniform character o f its intake into the organism with food and via contact surfaces (gills and skin). 118