Changes in aquatic ecosystems under the influence of gas pipeline «Bovanenkovo-Ukhta» construction and operation (the Kara river basin, Polar Urals and Bolshezemelskaya tundra)

Data on the impact of gas pipelines on the ecosystems of the Extreme North is scarce. The data on the condition of water currents of the Kara river basin in the zone of impact of gas pipeline route is presented. The Kara river and its tributaries Bolshaya Lyadgei-Yakha and Nyarma-Yakha are surveyed. The comparative analysis of background and impact areas in the zone of technogenic impact on the basis of algae species diversity, chemical composition of water and bottom sediments was carried out, signs of their technogenic pollution by oil products and heavy metals were also noted. The quality of the aquatic environment with use of indicator group of diatoms sensitive to various changes in ecological conditions was defined. The specific characteristics of algocenose diversity and structure in watercourses under the influence of pollutants are shown. Significant reorganization of aquatic ecosystems in natural complexes of the Polar Urals and Bolshezemelskaya tundra is established. Prevalence of species-indicators of water pollution by easily oxidized organic matter in parts of the rivers being under the anthropogenic impact, and decrease of the role of indicators of pure water is revealed. The main impact factors on aquatic ecosysyems at construction and operation of linear constructions in the zone of gas pipeline route are established. For preservation of territories of high nature conservation value it is necessary to work out nature-conservative measures on reduction of negative impact of economic activities and establishment of specially protected territories in lowland and mountain tundra areas.