Prog. Oceanogr. (2015)


The black guillemot is an ice-associated bird, spending winters in the Arctic pack ice and breeding close to the edge of the ice in summer. As a result of recent Arctic sea-ice loss, surface temperature in open waters has increased, causing a decrease in abundance of polar cod, the primary food source for black guillemot chicks.

George Divoky, of the Friends of Cooper Island, and colleagues combined monitoring records from a black guillemot colony in Alaska gathered from 1975 to 2012 with satellite records of sea-ice extent to examine the effect of recent ice loss on chick diet and condition.

They found that at the beginning of the records, the sea-ice edge was located approximately 100 km from the colony at the end of the breeding season. But in the past decade this distance has increased to 500 km, resulting in higher sea surface temperatures in foraging areas. At the same time, polar cod decreased from being the major food source for chicks (making up 95% of their diet) to comprising less than 5%, coinciding with a fivefold increase in chick starvation. ET