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

1.12.3. Hydrobiological studies No direct hydrobiological investigations have been carried out in this lake. Lake Poro­ jarvi is typically populated by fish species such as trout (Salmo fruffa), whitefish ( C ore­ g o n u s lavaretus), grayling ( Thumallus thumallus ), pike (Esox lucius), perch ( Perea £u- viatilis), burbot ( Lota lota), minnow ( Phoxinus phoxinus ), and nine-spine stickleback {Pungitius pungitius). 1.13. LAKE SARIJARVI Lake Sarijarvi (watershed of the River Pechenga) is located 15 km to the east of the town ofNikel and 7 km to the west of the town of Zapolyarny. It is a small (area of the lake 0.14 km2), shallow-water (maximum depth 2 m) almost oval lake of glacial origin with an indented coastline The maximum length is 0.7 km and maximum width 0.3 km. The point of maximum depth (2 m) is located in the southern part of the lake. The Kola Ultra-deep Well is located 1.5 km from the lake. According to the landscape type, the watershed area belongs to the tundra zone with heights ofup to 517.5 m (Vil- giskoddeoajvi fell). The lake shores are not high, and are rocky and covered with grass and shrub vegetation. The water of the lake is colourless. Boulder beds occur in almost parts of the littoral zone. The gaps between the boulders are filled with pebbles. Physico-geographical characteristics Watershed River Namajoki— River Pechenga Latitude 69°24.590' Longitude 30°37.484' Height above sea level, m 318.0 Maximum length, km 0.7 Maximum width, km 0.3 Maximum depth, m 2 Area, m2 0.14 Watershed area, km2 12.5 Study period 2004-2005 1.13.1. Hydrochemistry The lake is one of the most polluted lakes in the Pechenga area, due to its close proximity to the Pechenganikel smelter. Airborne pollution has a major impact on the water quality. The water of the lake is neutral, and the mean total mineralization is 31.2 mg/l and mean alkalinity 151 [ieq/1. The lake has relatively low concentrations of base cations and anions, with calcium (average 4.66 mg/l) and sulphate (aver­ age 11.3 mg/l) predominating. Based on the concentrations of min­ eral nutrients, the lake is classified as mezotrophic. The concentration of total P in the surface horizon is 20 [ig/1 and Hydrochemical properties pH 6.92 6.80-7.04 Electrical conductivity, mS/cm 50 49-50 Ca, mg/l 4.66 4.62-4.70 Mg, mg/l 1.19 1.16-1.22 Na, mg/l 2.14 2.08-2.21 K, mg/l 0.23 0.22-0.23 HC03, mg/l 92 8.7-9Я S04, mg/l 11.3 11.0-11.7 Cl, mg/l 2.39 2.29-2.48 Total mineralization, mg/l 31.2 30.7-31.6 Alkalinity, цед/І 151 142-160 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea