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

Fig. 48. Vertical distribution of the concentrations of Co, Pb and As (цд/д, dry weight) in the sediment core ofLake Samettivatn. 2.11.3. Hydrobiology investigations No direct hydrobiological investigations have been carried out in this lake. 2.12. LAKE SKRUKKEVATN Lake Skrukkevatn (watershed of the River Paz) is located 18 km to the north of the town of Nickel. The lake is not large (the area of the lake is 0.91 km2), the maximum depth is 15 m, has a close to oval shape, and is of glacial origin. The maximum length is 2.0 km and maximum width 0.7 km. The points of maximum depth are located in the cen­ tral part of the lake. The lake is used by inland water transport. The lake forms part of a lake-river system. According to the landscape type, the watershed belongs to the forest-tundra zone, with heights of up to 152 m. Boulder beds occur in almost all parts of the lit­ toral zone. The lake shores are high, and covered by grass and shrub vegetation and pine forests.The northern shore falls abruptly to the waterline. A road passes along the northern shore. The water of the lake is colourless. Physico-geographical characteristics Watershed River Paz (Skrukkebukta) Latitude 69°34.183' Longitude 30°03.023' Height above sea level, m 56.0 Maximum length, km 2.0 Maximum width, km 0.7 Maximum depth, m 15 Area, km 2 0.91 Watershed area, km 2 4.68 Study period 2004-2005 2.12.1. Hydrochemistry The pH of the water in the lake is close to neutral, and the water has a low total min­ eralization (average 19.8 mg/l) and alkalinity (average 82 |ieq/l). During flood periods the pH falls slightly, i.e. oxidation processes do not develop due to the buffering ca­ pacity of the water. The lake has low concentrations of base cations and anions, with sodium (average 2.80 mg/l) and bicarbonate (average 5.0 mg/l) predominating. The annual chemical cycle of the lake is characterized by a slight reduction in the oxidizability, mineralization and pH of the water during flood periods when the amount of precipitation and inflow of humic water increase. 100 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea