Salmon Advocates Challenge Weak Pesticide Controls in California’s Central Valley

Proposed plan to limit pesticide pollution not strong enough to protect salmon


Erin Tobin, Earthjustice, (415) 217-2000

Michael Coats, Golden Gate Salmon Association, (707) 935-6203

Fishing groups acted Monday to strengthen regulation in California of two widely used pesticides known to harm salmon. More than one million pounds of the two pesticides are used annually to kill insects on a variety of crops in California and much of it washes off fields or drifts from the air into salmon-bearing streams.

Chinook salmon.  (CA DWR)

The Golden Gate Salmon Association (GGSA) and GGSA coalition members Pacific Coast Federation of Fishermen’s Associations and Golden Gate Fishermen’s Association submitted formal comments asking the Central Valley Regional Water Quality Control Board to strengthen a draft plan to regulate the two poisons, diazinon and chlorpyrifos.

The fishing groups are represented by public interest law firm Earthjustice, which sent the comment letter late Monday in response to the Central Valley Water Quality Control Board’s draft plan controlling diazinon and chlorpyrifos.

“Salmon have a tough enough time surviving in California with the chronic manmade water shortage; we need to stop poisoning the rivers and streams where they reproduce,” said John McManus, executive director of the Golden Gate Salmon Association. “No one should be surprised that highly toxic agricultural poisons are damaging salmon.”

The National Marine Fisheries Service (NMFS) has determined that chlorpyrifos, diazinon, and a third widely used agricultural poison, malathion, are likely to jeopardize the continued existence of 27 species of endangered or threatened salmon and steelhead. NMFS found that current uses were likely reducing the number of salmon returning to spawn. In 1989, the U.S. Fish and Wildlife Service determined that diazinon jeopardized 84 threatened and endangered aquatic species and four listed avian species.

“Our salmon are our livelihood. Agriculture needs to find ways to live lighter on the land so California’s native wildlife, including salmon, thrive,” said Zeke Grader of PCFFA and GGSA.

“Agriculture needs to be responsible for the tons of poisons they dump on their lands that end up in the state’s rivers and streams used by the rest of us.”

Both diazinon and chlorpyrofos are broad spectrum organophosphate pesticides that originate from nerve gases developed during World War II. In addition to harming wildlife, they are highly toxic to humans, poisoning workers and communities in agricultural areas when the pesticides drift from fields.

“The U.S. Geological Survey has found that both diazinon and chlorpyrofos contaminate rivers throughout the west at levels harmful to fish or their food sources, which most people would agree is unacceptable,” said Roger Thomas of GGFA and GGSA. “We know that both poisons have been detected at levels harmful to salmon in the San Joaquin and Tulare basins, among other places.”

“These are some of the most toxic pesticide chemicals on the market, harming wildlife, people and the environment,” said Earthjustice attorney Erin Tobin. “The law requires a sound plan to control pesticide use and clean up our rivers so the ecosystem can thrive.”

Salmon. Both diazinon and chlorpyrofos are broad spectrum organophosphate pesticides that originate from nerve gases developed during World War II.  (Thomas B. Dunklin)

Chlorpyrofos is "very highly toxic" to fish according to U.S. EPA. It impairs fish reproduction by reducing egg production in fish. It inhibits juvenile salmon feeding behavior and swimming speed and harms the survival and reproduction of salmon food sources.

Diazinon impairs feeding, predator avoidance, spawning, homing and migration capabilities by impeding salmon sense of smell and leads to weakened swimming activity in juvenile trout. It’s also known to be acutely toxic to salmon food sources. Diazinon is used on a wide variety of crops including apples, blueberries, broccoli, cherries, cranberries, pears, spinach, and tomatoes. In 2004, EPA cancelled home uses of diazinon due to the extreme risks that it poses to children, but EPA has continued to allow farm uses of the pesticide.

Chlorpyrifos is one of the most widely used pesticides in the United States. The Environmental Protection Agency estimates that every year farmers apply more than 10 million pounds of chlorpyrifos on dozens of crops, ranging from apples and broccoli to walnuts and wheat. Most residential uses of chlorpyrifos were phased out or cancelled in 2000.

The fishing groups contend the draft plan is incomplete and inaccurate and urge the Central Valley Board to revise it. Among other deficiencies, the draft plan fails to include legally required provisions needed to control unhealthy levels of pesticides in Central Valley waters, including managing pesticide drift and providing a margin of safety to ensure the applicable water quality standards will be attained. It also fails to include reasonable assurances that proposed limits on the poisons will be achieved and therefore is unlikely to achieve the goals of clean water.

The plan will apply to an area encompassing 60,000 square miles, or about 40 percent of the state’s total area. The Central Valley Regional Water Quality Board is responsible for ensuring protection of water quality in the Sacramento and San Joaquin Rivers, along with their tributaries, the inland Delta, and the Tulare Lake Basin.

The draft plan estimates that agricultural sources will need to reduce chlorpyrifos discharges by between 57 percent and 99 percent. It envisions reductions required for diazinon of between 35 percent and 43 percent.

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