Three Common Pesticides Toxic to Salmon

All three of the pesticides assessed are neurotoxins. Exposure either immediately kills salmon or impairs their feeding, predator avoidance, spawning, homing, and migration capabilities.

Recent research has found that these pesticides can have "synergistic effects" on salmon, which means that exposure to mixtures of carbamates and other chemicals is more dangerous than exposure to the carbamates alone.

The 609-page document prescribes measures to keep these pesticides out of waters inhabited by salmon and steelhead in Washington, Oregon, California, and Idaho.

"Salmon runs all along the west coast are collapsing, and our rivers becoming a toxic soup of pesticides is surely one of the causes," said Glen Spain of the Pacific Coast Federation of Fishermen's Associations.

"This new NMFS decision will help keep pesticides out of salmon-bearing streams and is a step toward protecting these economically valuable salmon runs and the tens of thousands of jobs they support," he said.

Dead fish in a polluted stream (Photo courtesy MorgueFile)

Carbaryl is the second most frequently detected pesticide in U.S. surface waters. EPA has classified carbaryl as moderately toxic to most fish and highly toxic to aquatic invertebrates that serve as food sources for salmon and steelhead.

About 1.4 million pounds of carbaryl are used annually in the United States to kill pests on fruit, nut, vegetable, and grain crops and in oyster farming and lawn care. EPA has listed carbaryl as a likely carcinogen that poses significant health risks to farmworkers.

EPA classifies carbofuran as highly toxic to freshwater fish and very highly toxic to marine fish. Roughly one million pounds of carbofuran are used annually in the United States, primarily on corn, alfalfa, potatoes, pine seedlings, bananas grown in Hawaii, and spinach grown for seed.

EPA has classified methomyl as moderately to highly toxic to fish, and very highly toxic to freshwater invertebrates that serve as food sources for salmon and steelhead.

Some 2.5 to 3.5 million pounds of methomyl are used annually in the United States on apples, barley, blueberries, corn, grapes, oranges, potatoes, tomatoes, and wheat.

In accordance with the NMFS biological opinion, within one year, aerial applications of the three pesticides will be prohibited within 600 to 1,000 feet of salmon waters.

Ground applications of the three pesticides will be banned within 50 to 600 feet of salmon waters, and any application of the three pesticides will be forbidden when wind speeds are greater than or equal to 10 miles per hour.

"The federal government has a duty to protect imperiled salmon from these deadly pesticides," said Joshua Osborne-Klein, an attorney for Earthjustice, the environmental law firm that represented the salmon advocates. "It's high time we reduce or eliminate the use of deadly pesticides in order to protect salmon, an icon of the Pacific Northwest's natural heritage."

This biological opinion is the second issued in the last six months under a court settlement with fishermen and conservationists. The previous biological opinion covered three organophosphate pesticides.

Over the next three years, National Marine Fisheries Service will assess a total of 37 pesticides.

NMFS has now determined that current uses of all six of the pesticides it has reviewed so far are jeopardizing the existence of west coast salmon and steelhead.

The Environmental Protection Agency, the federal agency charged with regulating pesticide use, had earlier determined that many salmon runs were not at risk from these six pesticides.

The National Marine Fisheries Service review found serious flaws with EPA's analytical methods and conclusions, and determined that EPA underestimated the risk that the pesticides pose to salmon.

"Today's findings are an example of why it's so important for the fish and wildlife scientists at NMFS to provide an independent check on other agencies' findings about endangered species," said Osborne-Klein.

But in the final days of the Bush administration, the federal government weakened the protections provided by the consultation process between the two federal agencies that produced Monday's biological opinion.

"The Bush administration's warped interpretation of the law removed the voices of scientific experts responsible for protecting salmon," said Osborne-Klein. Those last-minute regulations are currently being reconsidered by the Obama administration.

Under the court order, the next biological opinion, reviewing 12 pesticides, is due on June 30, 2010.

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