Pesticides pollute salmon streams

Nationwide, pesticides pollute every single river and stream tested by the U.S. Geological Survey (Circular 1291). Many of the rivers and streams that support Pacific salmon and steelhead have been evaluated for pesticide contamination.

The most recent reports from U.S.G.S. found:

• Fifty pesticides in the Willamette River and its tributaries (Circular 1161)
• Thirty-eight pesticides in the Sacramento River and its tributaries (Circular 1215)
• Forty-nine pesticides in the San Joaquin-Tulare Basins (Circular 1159)
• Thirty-seven pesticides in the Puget Sound and its tributaries (Circular 1216)

Pesticides harm salmon and other wildlife

• In Willamette Valley rivers and streams eleven pesticides were found at levels harmful to fish and wildlife (Circular 1161)
• In Sacramento Valley rivers and streams four pesticides were found at levels harmful to fish and wildlife (Circular 1215)
• In the San Joaquin and Tulare basin nine pesticides were found at levels harmful to fish and wildlife (Circular 1159)
• Puget Sound rivers and streams had five pesticides found at levels harmful to fish and wildlife (Circular 1216, 097-99)

Concerns associated with some of the pesticides found in west coast watersheds.

• Carbaryl, an insecticide, reduces egg production and fertilization (Arunachalam, 1982); and reduces swimming speed in fish (Weis, 1974). At very low levels it can kill insects salmon eat (Burdick, 1960). Carbaryl, with the common product name of Sevin, is used both in and around homes as well as in agriculture.
• Diazinon, an insecticide, reduces sperm production in male salmon at extremely low levels (Scholz, 2000). Diazinon is used mostly in agriculture. (Household uses were phased out after concern for children's health arose).
• Triclopyr BEE, an herbicide, causes flared gills and disoriented swimming behavior in fish (Morgan, 1991). It is used to kill a variety of weeds in agricultural, ditch banks, along roads and many other settings. Common product names that include triclopyr BEE are Crossbow and Brush-B-Gone.
• Trifluralin, an herbicide, is rated as highly toxic to fish by the U.S. Environmental Protection Agency. It is used to kill unwanted grasses both around the home and in agricultural settings. A common product name that includes trifluralin is Gordon's Weed Preventer Granules.

Well Designed Protections Can Make a Difference

In the late 1970s the levels of molinate and other rice pesticides in the Sacramento River and its tributaries were found to be acutely toxic to fish. By the mid-1980s, after complaints of objectionable taste in drinking water, a management program was adopted to contain the pesticide-contaminated waters for a period of time to allow some of the pesticide residues to volatilize. The plan led to significant drop in water contamination.