- ANCHORAGE, Alaska (Reuters) - A study of pink salmon, still ailing a decade
after the Exxon Valdez oil spill off the coast of Alaska, suggests that
oil is 100 times more toxic to developing fish than previously believed
and that dangerous oil pollutants linger years longer than had been believed.
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- National Marine Fisheries Service (NMFS)
scientists began the study in 1993 after Alaska Department of Fish and
Game biologists were stumped by a mystery: Why were pink salmon spawned
in streams oiled by the disastrous 1989 Exxon Valdez spill still suffering
years later?
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- To find the answer, scientists in the
NMFS laboratory in Auke Bay, Alaska, simulated the salmon's spawning conditions.
They raised salmon in the laboratory in old, weathered oil like that persisting
on many beaches along Alaska's Prince William Sound years after the huge
tanker spill.
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- The result: juvenile fry with gross deformities
such as extra fins, retarded development or other problems that create
poor prospects for survival through adulthood.
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- "Think of fetal-alcohol syndrome
in humans," said Stanley Rice, an NMFS toxicologist and one of the
authors of the studies, which were presented at an Anchorage conference
in March. "In the wild environment, that's kind of what we're having
with the pink salmon fry."
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- The results contradict previous assumptions
that the light elements of oil, which cause acute effects on marine life
but evaporate within days, are the most toxic, he said.
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- "Back in the '70s we were thinking
mostly of the short-term toxicity. We really didn't think there would be
that many long-term effects."
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- Rice said the studies have caused scientists
to rethink water-quality standards. Even Alaska's standards, which are
the nation's toughest and restrict hydrocarbon pollution to 15 parts per
billion, may not be strict enough, he said.
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- The Auke Bay scientists found that weathered
oil even at the minute levels of 5 to 20 parts per billion caused salmon
to return as adults at rates 40 percent lower than normal.
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- "That's a pretty significant result
at the parts-per-billion level," Rice said.
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- Exxon scientists dispute the findings.
The company has long maintained that Prince William Sound was full of hydrocarbons
even before the 1989 disaster, the result of natural oil seeps, and marine
life there was accustomed to oil exposure.
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- But the Auke Bay scientists and researchers
from the U.S. Geological Survey have concluded that any background, non-spill
hydrocarbons in the sound came from coal, which sinks to the sound's bottom
and is locked in a crystalline structure unavailable to marine life.
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- The important source of oil in Prince
William Sound before 1989 was a spill of fuel from Valdez storage tanks
that were ruptured and toppled in a powerful earthquake that struck the
area in 1964, according to a study by Keith Kvenvolden of the U.S. Geological
Survey.
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- Rice said the scenic area, with only
a few thousand residents, will eventually heal from the 1989 disaster.
"Unless it has another Exxon Valdez, Prince William Sound is going
to do well from a wildlife perspective," he said.
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- But the outlook is much gloomier for
marine life in waterways near major cities like New York, San Francisco
and Philadelphia, where a constant flow of spilled oil and other pollution
is washed from streets and parking lots, he said.
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- "It's just the chronic input. These
are places where improvement is going to be very poor over the long run."
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