Sandimirov S.S. Catalogue of lakes in the Russian, Finnish and Norwegian Border Area. Finland, Jyvaskyla: Kopijyva Oy, 2008.

Table 44. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As C„ Kivijarvi 0-1 - 17 12 87 14 0.46 16 5.90 38-40 - 27 12 84 16 0.28 1.9 0.93 c, 0.6 1.0 1.0 0.9 1.6 8.4 6.3 19.9 3.3.3. Hydrobiological studies Ichthyofauna.. No direct hydrobiological investigations have been carried out in this lake. Lake Kivijarvi is a typical reservoir for such species as trout ( Salmo trutta), white- fish ( C oregonu s lavaretus), grayling ( Thumallus thumallus), pike (Esox lucius), perch ( Perea Ruviatilis), burbot ( Lota lota), minnow ( Phoxinus phoxinus ) and nine-spine stickleback ( Pungitius pungitius). Fish samples obtained from the lake are not numerous. Whitefish is represented by individuals with an average length of 24.5 cm and weight 207 g. The size of the largest specimens is 32.6 cm and 580 g, respectively. The age limit of the whitefish is apparently 8 years, 3- to 6-year-old specimens constituting the bulk of the population. Males are predominant over females (1.9:1). The mean length and weight of the pike are 45.4 cm and 687 g, respectively, 7-year-old individuals have a weight of 900 g and length of 50.0 cm. H eavy m eta ls in fish The heavy metals concentrations (Cu, Ni, Pb, Cd and Hg) in fish muscle do not exceed the standard values (Table. 45). The Cu concentrations in the liver of whitefish and pike (pg/g dry weight) are up to 37.4 and 9.6 pg/g, respectively, and Ni in the kidneys of whitefish up to 2.8 pg/g. Cd accumulation in fish kidneys is higher than that in muscle, while the corresponding Hg concentrations are double thay in muscle. Analysis of the heavy metal accumulation in different fish species show that Ni (in kidneys) and Cu (in liver) accumulate the most strongly in whitefish (Fig. 69). There are no significant differences in Pb accumulation between the muscular tissue of whitefish and pike, whereas the Hg concentration in pike muscle is higher than that in perch (Fig. 69). Standard value (pg/g wet weight)* Concentration in muscle (pg/g wet weight) Concentration in muscle (pg/g of dry weight) Whitefish Hg 0.5 0.08 0.35 Ni 0.5 0.13 0.60 Cu 20 0.18 0.83 Cd 0.1 0.002 0.01 Pb 1 0.02 0.08 Pike Hg 0.5 0.24 1.22 Ni 0.5 0.16 0.82 Cu 20 0.22 1.10 Cd 0.1 0.002 0.01 Pb 1 0.02 0.08 * Source: Sanitary..., 1986. The organic matter con­ tents (LOI, %) and heavy metal concnetrations (цд/д, dry weight) in the surface (0-1 cm) and pre-industrial (38-40 cm) sediment layers. Cfand Cdrefer to the contami­ nation factor and degree ofcontamination values, respectively. Table 45. The standard values for heavy metal concentra­ tions in foodstuffs and in fish muscle in Lake Kivijarvi (in цд/д wet and dry weight). Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea 123