Bird Droppings Pollute Arctic

Area 1002, a section inside the Arctic National Wildlife Refuge in Alaska, proposed to be used for oil exploration by the Bush administration, is shown in this undated file photo. (Arctic National Wildlife Refuge)
A major source of chemical contamination in the Arctic turns out to be bird droppings.

Wind currents and human activities long have been blamed for fouling the pristine Arctic. But a study by a group of Canadian researchers found that the chemical pollution in areas frequented by seabirds can be many times higher than in nearby regions.

Researchers led by Jules Blais of the University of Ottawa studied several ponds below the cliffs at Cape Vera on Devon Island in the Canadian Arctic.

Scientists report in Friday's issue of the journal Science that the ponds, which receive falling guano from a colony of northern fulmars that nest on the cliffs, have highly elevated amounts of chemicals.

"If long-range transport was the only thing bringing these chemicals north, we would expect to see a very even distribution," Blais said in a telephone interview.

But the chemicals are concentrated in some places, he said, "and we have found a reason ... they can follow biological connections."

Blais calls it the boomerang effect.

"These contaminants had been washed into the ocean, where we generally assumed they were no longer affecting terrestrial ecosystems. Our study shows that sea birds, which feed in the ocean but then come back to land, are returning not only with food for their young but with contaminants as well. The contaminants accumulate in their bodies and are released on land," Blais said.