Black guillemots breeding in an Arctic Alaska colony feed their chicks on polar cod. 
These small fish are associated with the polar pack ice, and therefore may become in short supply for breeding guillemots as local sea-ice extent retreats.
Black guillemots breeding in an Arctic Alaska colony feed their chicks on polar cod. These small fish are associated with the polar pack ice, and therefore may become in short supply for breeding guillemots as local sea-ice extent retreats.