- TORONTO (Canadian Press)
-- Seabird droppings are leaving more than a foul mess in the Arctic they
are contaminating northern lakes and ponds with extremely high levels of
mercury and DDT, Canadian researchers have found.
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- Concentrations of the chemicals were found to be as much
as 60 times higher in bodies of water on Devon Island, Nunavut, than in
other Arctic areas, a study to be published Friday in the journal Science
says.
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- Inland layers of sediment less than one centimetre thick
were analyzed last summer at Cape Vera, 1,800 kilometres north of Iqaluit
on the island's north shore, where 20,000 northern fulmars nest annually.
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- The samples revealed that their guano, laden with mercury,
DDT, PCBs and pesticides, gradually oozed down fortress-like cliffs 250
metres high and into surrounding shallow freshwater lakes and ponds.
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- The fulmars, which look like the common gull and dine
on zooplankton, squid and fish in the Atlantic Ocean, are picking up the
pollutants from their aquatic feast and funnelling the waste back into
relatively untouched ecosystems, said John Smol, a biology professor at
Queen's University in Kingston, Ont.
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- "One can easily say, 'So what? You've got these
ponds up in the high Arctic that have higher DDT and higher mercury,'"
Mr. Smol said via satellite phone from Resolute Bay, Nunavut.
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- The birds are creating a "boomerang effect,"
however, whereby industrial pollutants thought to be forever lost in the
ocean hundreds of kilometres away are returning to the continent and threatening
land species, he said.
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- "(Water) insects are eaten by the birds, the birds
are eaten by the foxes," Mr. Smol said. "It's quite possible
we have a whole new mechanism of (pollutants) going back in to the terrestrial
ecosystem."
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- The birds are the dominant species in the region and
are single-handedly responsible for biological activity in the area, said
Jules Blais, an environmental toxicology professor at the University of
Ottawa.
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- That makes their impact on the local environment more
pronounced, said Mr. Blais, who suspects that the phenomenon is not limited
to Devon Island, the largest uninhabited island in the world.
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- "There are other seabird colonies distributed throughout
the Arctic that would have this kind of effect because they nest in large
densities together," said Mr. Blais, who led the study.
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- "These chemicals don't observe international borders,
obviously."
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- There are about 10 million seabirds that colonize the
Canadian Arctic, creating a risk that humans could be exposed to dangerously
elevated levels of the pollutants.
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- Northern Canadian populations are already among the most
mercury and PCB-exposed people on the planet, and their diets, largely
derived from Arctic freshwater systems, put them at greater risk, researchers
say.
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- The study highlights the need for industries to be more
environmentally sound in their practices, Mr. Blais said.
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- "Really, the only thing that can be done is to gradually
phase these chemicals out. There's no way you can stop these processes
by trying to intervene, you can't extinguish (them)."
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