3 Pesticides Singled Out
by Robert McClure
From Los Angeles to the Canadian border, three pesticides synthesized in the 1950s and '60s are increasing the chance of extinction for more than two dozen imperiled salmon stocks, says a draft study by federal fisheries experts.
"Overwhelming evidence" suggests the pesticides are interfering with the ability of salmon to swim, find food, reproduce and escape bigger fish trying to eat them, says the evaluation issued by the National Marine Fisheries Service.
The fish in question, all protected under the Endangered Species Act, include threatened Puget Sound chinook.
If the pesticides are used as currently authorized by regulations, "all (threatened salmon) populations will likely show reductions in viability," the 377- page study concludes.
The report came in response to a suit filed by environmentalists in federal court in Seattle, where U.S. District Judge John Coughenour ordered the Fisheries Service to conduct the study.
It is intended as advice to the Environmental Protection Agency, which governs use of pesticides. EPA has long allowed use of the pesticides in what the fisheries service now says are applications dangerous to fish.
"It seems to be a very thoughtful and fair opinion," said Joshua Osborne-Klein, a lawyer with the Earthjustice law firm in Seattle who represented the Northwest Coalition For Alternatives to Pesticides, Pacific Coast Federation of Fishermen's Associations and the Institute for Fisheries Resources.
The release of the Fisheries Service evaluation of the three pesticides comes as the Bush administration moves to curtail how often federal agencies including the EPA have to check with federal wildlife scientists on actions that affect endangered species. In this case, it was EPA's approval of the pesticides.
Environmentalists said the study provides a compelling argument against cutting back on such advice.
"These are pesticides that EPA has swept under the rug for years," Osborne-Klein said. "These are three that stood out as the nastiest of the (pesticides) that are still in widespread use."
The fish scientists will soon review 34 other, newer pesticides to see how they affect salmon as part of a settlement with environmental groups. The first three pesticides considered were:
Heather Hansen, director of the pro-pesticide Washington Friends of Farms and Forests, questioned some of the assumptions used by Fisheries Service scientists. In one exercise, for example, fisheries scientists said concentrations of chloripyrifos as low as 3 parts per billion could kill half the fish exposed over a four-day period.
"That's what happens if you hold them in that concentration for four days. That never happens in the real world," Hansen said. "It tends to be a pulse, and then it's gone."
She said measurements in the field by the Washington Ecology Department are finding "very, very, very low levels - levels that are far, far below what have ever been considered cause for concern."
However, the Fisheries Service study said at the concentrations expected in the wild, "population abundance likely would decline and recovery efforts would be slowed ... risk of extinction would increase substantially."
Small side channels where salmon are most likely to hang out when they are young are the part of the streams where pesticide concentrations tend to be highest, the study says.
For fish not killed outright, the study says, the pesticides' tamping down of the salmon's sense of smell is particularly important, because young salmon learn to avoid predators when they smell the blood of other young fish in the water. If they fail to pick up the scent, they get chomped, too.
The insecticides also impair the salmon's ability to swim.
And insecticides harm salmon in another way, the study says: They kill off the insects that young fish eat. So the young fish are hungry as well as hit by toxins.
Adult salmon are affected, too. If their sense of smell is diminished, it can interfere with reproduction, because female salmon use a special odor to signal males that it's time to excrete their sperm.
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