Phytobenthic communities of the Barents Sea arctic zone and climate change

The study of species structure of benthic seaweeds populations in plant communities of the coastal Arctic zone of Arctic archipelagoes of the Barents Sea on the basis of expeditionary works' materials has been carried out. The use of benthic phytocoenoses occupying a certain biotope with characteristics of ground features, currents, ice conditions while assessing the ecological state of marine coastal Arctic ecosystems has been substantiated. The species composition of phytocoenoses of open and ice-covered areas of the sea is different. It has been established that in extreme Arctic conditions the open areas are characterized by relatively high species diversity. On the contrary at ice-covered areas the reduction of species diversity, the belt distribution of algae and simplification of the community structure as a result of reducing the links between algal populations take place. Algae in such communities are related to each other and to other benthic organisms by topical, trophic and mediative connections. The use of plant communities, rather than individual species of algae as biological indicators and monitors, allows obtaining more complete information about the ecological state of coastal biocoenozes and the ecosystem as a whole. The results of the study can also be used in forecasting the state of the biotic community under climate change in the Arctic zone of the Barents Sea. The similarity of the species composition of the phytocoenozes of the Arctic zone with those living in the boreal zone of the sea, including the Murmansk coast, with a high coefficient of floristic similarity, allows us to conclude that a possible warming will lead to formation of benthic plant communities with characteristics typical for the southern regions of the Barents Sea.