Patterns of spatial and temporal dynamics of mixed Mytilus edulis and M. trossulus populations in a small subarctic inlet (Tyuva Inlet, Barents Sea)

Subarctic populations of “cryptic” blue mussel species Mytilus edulis ( ME ) and M. trossulus MT are less studied than Arctic boreal populations. Ecological features in sympatry poorly known everywhere. We the habitat segregation interannual dynamics their mixed settlements at Murman coast Barents Sea, northeastern boundary Atlantic littoral communities. Previous data on mussels from this area 50-100 years old. The 3-km-long Tyuva Inlet (Kola Bay) was used as study site. Mussels were found sublittoral down to a depth 4 m. Their characteristic habitats sandbanks, rocks, kelp forests “the bed” freshened top inlet. main spatial gradients explaining variability demographics (abundance, age structure, size) associated with distance inlet top. partially segregated by depth: dominated , littoral. In addition, throughout bed. ratio varied over time: between 2004 2010 proportions decreased everywhere, 22% average. distribution apparently changed we that abundant forests, where they had rarely been observed 20th century. suggest temporal subarctic can be partly explained competition differing sensitivity environmental factors.