Polar bears' diet moves to 1 with higher contaminant loads

A diet change for the East Greenlandic polar bear population in recent years has exposed the bruins to more contaminants, an international study indicated. The East Greenlandic polar bears live in an area where the decline in the ice sheet occurs at a rate of almost 1 percent a year, one of the highest rates measured in the entire arctic region, Aarhus University in Denmark said Tuesday in a release. Researchers at the Danish university, the Greenland Institute of Natural Resources and a number of Canadian institutions examined how the shrinking ice sheet affects the prey of the polar bears and the bears' intake of contaminants. The researchers studied the fatty acid profiles in the adipose tissue extracted from 310 polar bears hunted by East Greenland Inuits from the Scoresbysund area from 1984 to 2011, the university said. The composition of fatty acids in the bears' fat reflects the profile of fatty acids in their diet. Over the past 30 years, polar bears increasingly swapped out ringed seal with harp seal and hooded seal in their diet, exposing the polar bears to more contaminants, the study indicated. "The problem is that the sub-arctic seals that the polar bear has switched to have a higher content of contaminants because they live closer to the industrialized world and are higher up in the food chain," Professor Rune Dietz of Aarhus University said. Long term, researchers said, the polar bear may lose access to sub-arctic seals that depend on packed ice to give birth to their cubs and to be exposed to sunlight to form vital vitamin D.