Ecological state of aquatic biocenoses in the streams of the Kola basin, Barents Sea

Abstract

The ecological state of freshwater ecosystems is essential because they are actively used in human economic activities. As the habitats of valuable commercial fish species deteriorate, their population decreases rapidly. Therefore, environmental monitoring of water bodies, markedly affected by human activities, contributes to efficient natural resources management. Thus, analysis of recent data on the state of river ecosystems in the Kola Bay basin is of great interest. It shows the current state of biocenoses in some of the streams flowing into Kola Bay of the Barents Sea, an environmentally unsafe area on the Kola Peninsula. Studies have shown that in spite of ongoing human activities in the Kola Bay watershed, the state of the ecosystems in local streams generally remains satisfactory. The distribution density of Atlantic salmon juveniles in the tributaries of the Nizhnetulomsky Reservoir varies from 20 to 70 juv./100 m2. The distribution indices of trout in the River Bolshaya Lavna vary from 5 to 65 fish/100 m2 and those in streams from 10 fish/100 m2 (Goryachev Brook) to 18 fish/100 m2 (Tretiy Brook). The main factor which negatively affects the reproduction of diadromous fish species is hydrolic construction which results in the decrease of the Atlantic salmon, sea trout and whitefish stock. To efficiently maintain the ecosystems of the streams, the construction of fish-screening structures, the river channels should be recultivated and the artificial reproduction of valuable fish species should be launched.