Poisoned Killer Whales? Blame Salmon
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- jefftego
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more from News:
http://www.sciam.com/article.cfm?id=salmon-to-blame-for-poisoned-kill...
The most contaminated wildlife on Earth—killer whales in the Pacific Northwest—are picking up nearly all their chemicals from Chinook salmon in polluted ocean waters off the West Coast, according to a new scientific study.The whales, which feed in coastal waters from British Columbia's Queen Charlotte Islands to the San Francisco area, were declared an endangered species in the United States and Canada after their numbers shrank.
Their summer habitat around Puget Sound is "a hot spot for PCBs" as well as "lots of other contaminants," including dioxins and chlorinated pesticides, Ross said. The Chinook salmon they eat inhabit ocean waters and rivers polluted by agriculture, pulp mills, other industries, military bases and urban runoff.
Ross and his colleagues discovered that 97 percent to 99 percent of contaminants in the Chinook eaten by these whales originated from the salmon's time at sea, in the near-shore waters of the Pacific. Only a small amount came from the time the salmon spent in rivers, although many of the rivers are contaminated, too, Ross said.
"Salmon are telling us something about what is happening in the Pacific Ocean," Ross said. "They are going out to sea and by the time they come back, they have accumulated contaminants over their entire time in the Pacific Ocean."
Killer whales are perched at the very top of the food web, which makes them susceptible to pollutants in the ocean. Industrial compounds and pesticides such as PCBs, DDT and brominated flame retardants build up in food chains, their concentrations multiplying each step up from prey to predator.
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read more in article. It is really sad how immediately threatened killer whales are from pollution and other threats.
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