Research: Bird Droppings Major Source of Arctic Pollution
JENNIFER LUDDEN, host:
Researchers have long known that winds carry pollutants north from warmer climates to above the Arctic Circle. Now a letter in the latest issue of Science magazine confirms there is another carrier for these pollutants: seabirds. NPR's John Nielsen has more.
JOHN NIELSEN reporting:
Devon Island is an isolated set of rocks in the Canadian arctic. People who have been there say most of the island is not only devoid of wildlife but of any kind of life.
Mr. JULES BLAIS (University of Ottawa): Hardly any vegetation at all. This is the most nutrient-impoverished environment I've ever seen.
NIELSEN: Jules Blais is an environmental toxicologist with the University of Ottawa. He says the only green spots on Devon Island are the ones near the ponds found below the rocky cliffs, where as many as 20,000 seabirds called arctic fulmars breed.
Mr. BLAIS: There is lush moss and lichen growth happening just below them. And there are ponds that are green with algae, and these algae are supporting insects, which in turn support birds, like snow buntings. So there's an entire ecosystem that is built under these seabird colonies that are nesting up on these cliffs.
NIELSEN: Blais says these are ecosystems based on bird poop, and he means that literally. Giant mounts of nutrient-rich guano have been building up here for centuries. Now you and I might choose to avoid a giant mound of nutrient-rich guano, but to Blais they're scientific gold mines. Recently they helped him answer a question that's been dogging toxicologists since the late 1960s: How do pollutants, like PCBs and mercury, get from warmer climates up to the arctic?
Mr. BLAIS: What we are seeing is that some of the aboriginal people in the far north are among the most PCB- and mercury-exposed people on Earth. And so why would this be happening?
NIELSEN: Blais says it's happening partly because winds and clouds bring pollutants north. Other pollutants build up in the bodies of fish, squid and plankton. They get to places like Devon Island in the stomachs of the seabirds that eat them.
Mr. BLAIS: The seabirds are effectively acting like funnels that take this mass that is widely distributed over a large area and concentrating it into a small area. So this has the effect of producing hot spots of contaminants.
NIELSEN: Blais says his analyses of samples of guana from Devon Island have turned up high levels of long-banned chemicals like DDT and PCBs. They've also turned up very high levels of toxic mercury, a pollutant produced by coal-fired power plants all over the world. Blais doesn't know whether the pollutants he's identified are building up or disappearing, but he has drilled a lot of cores through the guano deposits that should allow him to find out. Robert Risebrough, a toxicologist with the Bodega Bay Institute in Berkeley, California, says those cores will make for interesting reading.
Mr. ROBERT RISEBROUGH (Bodega Bay Institute): We have very few data on what the long-term trends actually have been, and it'll be extremely worthwhile to look at the cores.
NIELSEN: So far there's no evidence that the toxins in the mounds on Devon Island have been hurting birds or wildlife. But if mercury levels turn out to be rising, Jules Blais thinks it won't be long before these levels exceed health standards and the Canadian government is forced to ban fishing near the island.
Mr. BLAIS: In the places that are adjacent to these seabirds, that are closest to these seabird colonies, we are starting to approach and exceed those guidelines. So that is our first indication that these chemicals could be causing harm.
NIELSEN: Blais says he's planning to look at other arctic seabird colonies in the area soon. John Nielsen, NPR News, Washington.
LUDDEN: This is NPR News.
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