Features of the biology of the bivalve mollusk Macoma calcarea (Gmelin, 1791) in the fjords of the island of Western Svalbard

The features of distribution and biology of the bivalve mollusk Macoma calcarea in the fjords of Western Svalbard in 2015 were established. Due to the high water temperature, the most favorable conditions for the formation of settlements with a diverse size and age structure of Macoma calcarea are characteristic of shallower fjords (for example, the Grenfjord). The least favorable conditions are typical for isolated fjords with negative water temperatures. The settlements of Macoma calcarea in the fjords of Svalbard can be considered unstable due to the abundance of juveniles in their composition. The predominance of females over males is noted everywhere, and reproduction begins at a smaller size than in the east of the Barents Sea.