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

Table 15. The organic matter contents (LOI, %) and heavy metal concentra­ tions (pg/g, dry weight) in the surface (О-1cm) and pre-industrial (26-27 cm) sediment layers. Cfand Cdare con­ tamination factor and degree of contamination values, respectively. Lake Layer, cm LOI Cu Ni Zn Co Cd Pb As Hg Cd Alla-Akkajarvi 0-1 26-27 35.20 29.48 112 12 321 12 95 103 23.0 9.0 0.36 0.05 28.2 2.6 3.83 1.86 0.134 0.010 cf 9.4 27.0 0.9 2.5 6.6 10.7 2.1 13.5 72.7 Fig. 12. Vertical distribution of the concentrations of Ni, Cu, Pb, Cd and Hg (pg/g, dry weight) in the sediment core of Lake Alla-Akkajarvi. 1.15.3. Hydrobiological studies No direct hydrobiological investigations have been carried out in this lake. The typi­ cal fish fauna in Lake Alla-Akkajarvi are trout ( Salmo trutta), whitefish ( C oregonu s lavaretus), grayling (Thumallus thumallus ), pike (Esoxlucius), perch (Perea fluviatilis), burbot ( Lota lota), minnow ( Phoxinus phoxinus) and nine-spine stickleback ( Pun gi­ tius pungitius). 1.16. LAKE KOCHEJAUR Lake Kochejaur (watershed of the River Madsash - tributary of the River Lotta) is located 6 km from the Russian-Finnish border, 110 km to the south-west of the town of Nikel, and 15 km to the north of the “Lotta”border crossing point. It is a small (area of the lake 3.2 km2), shallow-water (average depth 2 m, maximum depth 8 m), elongated (north to south) oval lake of glacial origin. The maximum length is 5.6 km and maximum width 1 km. The point ofmaximum depth (8 m) is located in the central part of the lake. In the northern and southern parts of the lake the maximum depths are small - only down to 4 m. The lake bay, adjoining the lake in the south, contains shallow water (1-2 m). The lake belongs to the lake-river system of the River Madsash, which flows into and out of a small shallow-water stretch in the southern part of Lake Kochejaur. Ac­ cording to the landscape type, the watershed consists of a combination of flat low-ly- ing areas of glaciolacustrine flatland, with denudation and denudation-tectonic massifs with abrupt outcrops of quaternary deposits reaching to a height of 187 m. The lake shores are high and covered with pine forest. Waterlogged shores with protrusions of 48 Catalogue ofLakes in the Russian, Finnish and Norwegian Border Area