Ecology and distribution of the Iceland scallop Chlamys islandica (O. F. Muller, 1776) in the Kola bay (the Barents Sea)

Assessment of the current state (distribution, allocation features, size structure, habitat conditions) of the Iceland scallop Chlamys islandica settlements in the Kola Bay has been carried out. Material for the study was collected in the upper subtidal zone by scuba divers at 12 research areas. It has been established that at present in the bay the scallop is widespread. This species occurrence is higher on the hard bottom and shell rock than on the soft bottom. The scallop numbers increases from the inner to the outer region of the bay. The weight-average density varies from 0.01 to 5.56 ind/m2 and the biomass varies from 0.5 to 225.0 g/m2. The scallops can form the local aggregations with density of 15 ind/m2. The mollusks settlement density is comparable with that in other bays of the more environmentally friendly areas. The size structure of mass aggregations has a monomodal character that demonstrates a weak replenishment of shallow-water settlements by juveniles. The Iceland scallop inhabits the upper subtidal zone of the Kola Bay with the water temperature equal to 2.8-11.8 °C and the salinity - 31.4-35.6 ‰. The abundance and size composition of scallop in the middle of the bay is under the influence of illegal non-commercial fishing. The received data on distribution and dimensional structure of the Iceland scallops can form a basis for monitoring conditions of bottom fauna of the Kola Bay and also for monitoring the possible changes in the Arctic ecosystem caused by climatic fluctuations or anthropogenic influence.