全球变化知识资源中心

Ichthyological studies are an important part of the research effort on the water ecosystems of the Arctic. However, data on the changes in the ichthyofauna of the Arctic seas are scarce and contradictory. We studied species composition of trawl catches made in 1980-2015 in the coastal and the open part of the Pechora Sea (south-eastern Barents Sea). We determined the relative abundance (individuals per hour of trawling) of the dominant fish species in the coastal and the open zone and described the taxonomic status of fish and their ecological grouping by distribution area and predominant type of feeding. Cluster analysis revealed four groups of study years similar in respect of the proportion of dominant fish species in trawl catches. The species diversity of the ichthyofauna increased over the study period and so did the number of predominantly Arctic species in the catches. On the contrary, the proportion of Arctic species such as polar cod decreased. In our opinion, this was caused by the changes in the mean water temperature, which showed a tendency to increase over the study period. A comparative analysis of the ichthyofauna of the Pechora Sea and the Baydaratskaya Bay of the Kara Sea revealed differences in the dominance of Arctic and boreal fishes, which might have been associated with the differences in the mean annual temperature in these water bodies. Our results can be used as background data for further monitoring of climate change.