Polar bears in eastern Greenland have taken to dining on the unhealthy table scraps of climate change. Melting Arctic sea ice has depleted the population of ringed seals that once formed the main course of the bears' buffet. As the bears switched to harp and hooded seals, the predators received a side order of pollution.
"The problem is that the sub-Arctic seals 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," said Rune Dietz of Aarhus University in a press release.
Polar bears, like orcas and humans in the Arctic, collect high levels of pollutants because these top predators acquire all the toxins that their prey (and their prey's prey) built-up over the years.
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The polar bears harbored chemicals like the pesticide DDT, polychlorinated biphenyls (PCBs), and other materials, known as persistent organic pollutants (POPs), according to research by Dietz and an international team of environmental scientists. Although regulation in the industrialized world limits the production and release of these chemicals, the toxins remain in the polar bears' systems. "We can see that the content of the POPs after year 2000 decreases slower in the polar bear than in the ringed seal," Dietz added.