for National Geographic News
The Arctic's killer whales are highly contaminated with man-made chemicals and are now considered to be the region's most toxic creatures, a new study reports.
The marine mammals carry distressingly high levels of polychlorinated biphenyls (PCBs), pesticides, and brominated flame-retardants.
"This new killer whale research reconfirms that the Arctic is now a toxic sink," said Brettania Walker, toxics officer with the World Wildlife Fund (WWF) International Arctic Programme.
"Chemicals in everyday products are contaminating Arctic wildlife."
WWF helped fund Hans Wolkers, a toxicologist with the Norwegian Polar Institute (NPI), who sampled blubber from killer whales, or orcas (Orcinus orca), in Tysfjord, Norway.
Wolkers hunted the elusive whales and darted them with a special gun that removes a sample of tissue to test the level of toxins retained in their blubber.
"It's difficult to get close, and we had some problems with the equipment, because it was not designed for these huge beasts," he reported. "It was designed for dolphins, and these killer whales are as big as elephants."
Wolkers found that the whales retained even more toxins than polar bears, which had been believed to be the region's most toxic animals.
The finding raises the question: How did one of the planet's most untrammeled corners become a repository for these toxins?
"Most of these chemicals are not produced or widely used in the Arctic," WWF's Walker said. "But air and ocean currents are going [predominately] northward.
"So the final destination of these pollutants, which are used in developed and increasingly in developing countries, is the Arctic."
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