With rising levels of toxins in the Arctic threatening wildlife and humans alike, scientists are on the hunt for what's behind the pollution boom. Wind currents carrying pollutants from industrialized countries are known to be largely responsible for toxins in the Arctic seas. But on the coasts birds are the key culprits, a new study says.
Researchers who studied a large seabird colony in the Canadian Arctic found that ponds below the birds' breeding cliffs are laced with persistent organic pollutants, or POPs.
The birds, it seems, are eating carrion, squid, and other marine animals from POP-contaminated seas. The flyers then return to their coastal home and deposit their contaminated prey—in the form of excrement—in local ponds, which see their POP levels skyrocket as a result.
Experts say the study adds to concerns over the impact of toxic substances on the health of the Arctic's wildlife and people.
"What's unique about this study is that it identifies a new method of bio-transmission that's potentially causing contamination to the local environment," said Russel Shearer. Shearer is the manager of the Canadian government's Northern Contaminants Program, based in Hull, Quebec. The program investigates the risks and impacts of chemical pollutants to remote communities in northern Canada.
"Such contamination should be taken more seriously," Shearer added.
The researchers' findings are based on observations of a colony of more than 20,000 northern fulmars at Cape Vera on Devon Island in the Canadian province of Nunavut. The study will be reported tomorrow in the journal Science.
"This mode of chemical movement can lead to surprisingly high levels of contaminants, because the contaminants are first accumulated in the food chain and then funneled into relatively small areas where the birds nest," said the study's lead author, Jules M. Blais. Blais is a biogeochemistry professor at the University of Ottawa, Ontario.
Northern fulmars are a keystone Arctic species, providing vital nutrients to an otherwise desolate landscape.
"We have a unique ecological situation, where birds that feed over the ocean are nourishing an entire ecosystem under their cliffs," Blais said. "If the seabird colony left, mosses, lichen, insects, and small birds like snow buntings—and even small carnivores like foxes and jaegers [a type of large bird]—would probably be displaced or disappear altogether."
But the "biological pump" provided by seabirds is now also transporting industrially produced contaminants.
Polluted Ponds
|
SOURCES AND RELATED WEB SITES
|
