State of the Arctic Marine Biodiversity Report: chapter 3.4: Marine fishes

Fishes chapter of the State of the Arctic Marine Biodiversity Report covering three Focal Ecosystem Components: Greenland halibut, polar cod and capelin.

Arctic marine fish communities are changing as the result of altered environmental conditions. Elevated ocean temperatures and altered stratification, wave action and the availability of ice habitats are driving changes in habitat use patterns. Changes in habitat allow the northward expansion of bordering species, often altering competitive and predator-prey interactions. For example, the northward movement of capelin (a complex of Mallotus species) in Canadian Arctic waters represents the appearance of a competitor for current keystone forage fishes such as polar cod (Boreogadus saida), whereas the expansion of Atlantic cod (Gadus morhua) has led to greater predation pressure on polar cod in the northern Barents Sea.