October 21st, 2010
By: David Gutierrez
The excrement of Arctic seabirds is a cocktail of dangerous pollutants, according to studies conducted by the Canadian Wildlife Service and Queen’s University in Kingston, Ont.
Because nearly all pollution emitted by industrial societies ends up in the ocean eventually, sea creatures are among the most contaminated organisms on the planet. Sea birds such as terns, eiders and fulmars eat these organisms, thereby creating a “boomerang effect” and bringing many of the toxins back to land.
“At the end of the day, it’s a sad tale, that the oceans are polluted no matter where you are — that’s the bottom line,” said researcher Mark Mallory.
In the most recent study, published in the Proceedings of the National Academy of Science, researchers identified one pond used by terns and another used by eiders on Tern Island off the coast of Cornwallis Island. They sampled the sediment from the bottom of each pond and tested them for contaminants. They found significantly elevated levels of cadmium and mercury in the pond used by terns, which eat mostly fish. In the excrement of eiders, which eat mostly shellfish, they found elevated levels of lead, manganese and aluminum.
A prior study, also conducted by Mallory, found elevated levels of PCBs and DDT in the excrement of fulmars on Devon Island, one of the most isolated locations in the world. Concentrations of the chemicals were as much as 60 times higher in ponds used by the birds than in other ponds nearby.
“The birds are like a funnel and they’re concentrating these contaminants, ” researcher John Smol said.
Although researchers say the contaminants found are not concentrated enough to pose a health threat to the indigenous Nunavummiut who eat eiders and the eggs of eiders and terns, they do pose a threat to birds themselves, and to the wider Arctic ecosystem.