Climate changes have forced the Arctic polar bears to alter their diet from ringed seal to harp and hooded seals. But these seals are highly contaminated.
The Arctic is going to witness a significant rise in temperatures and warmer climatic conditions in the future. Therefore, a team of researchers from the Greenland Institute of Natural Resources, Aarhus University (Denmark) and a number of Canadian institutions conducted a study to see how these climatic changes will affect the Arctic polar bear in the future.
For the study, they examined the fatty acid profiles in a unique material collected from over 310 polar bears that were hunted by East Greenland Inuits from the Scoresbysund area in the years 1984 to 2011.
The analysis confirmed that polar bears feed on three species of seals including ringed seals, harp seals and hooded seals. Researchers also found that the diet of these bears had changed dramatically over the 30 years during which the samples were collected. During this period, the consumption of ringed seals decreased by 42 percent while the consumption of the other two sub-Arctic seals increased.
Researchers also observed that though at first glance, these polar bears appear to be in a better condition now, the contamination levels in their food has increased by quite a big margin.
"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, Aarhus University said in a press release. "Therefore, climate change undermines the improvements that you would otherwise have obtained owing to international regulations in the use of environmental use of persistent organic pollutants (POPs). We can see that the content of the POPs after year 2000 decreases slower in the polar bear than in, the ringed seal."
Researchers also worry that over time, polar bears may lose their access to these sub-Arctic seals too as they require packed ice to give birth to their cubs and the rapid melting of ice sheets may make this difficult.
