PANNA: Pesticides Threaten Birds and Fish in California


Pesticide Action Network Updates Service (PANUPS)

Pesticides Threaten Birds and Fish in California

June 4, 1999

Pesticides continue to be a pervasive threat to California’s ecosystems according to a report released by Pesticide Action Network North America (PANNA) and Californians for Pesticide Reform (CPR). The report, Disrupting the Balance: Ecological Impacts of Pesticides in California, calls on the California Environmental Protection Agency and the federal government to ban three pesticides–the organophosphate insecticides diazinon and chlorpyrifos, and the carbamate insecticide carbofuran.

Over the last 30 years, the agrochemical industry has turned from organochlorines such as DDT to these neurotoxic organophosphate and carbamate pesticides. Use of these toxic nerve poisons continues to grow, with an 18% increase in California between 1991 and 1995. In California, some 17 million pounds of organophosphate and carbamate pesticides are applied annually in urban and agricultural settings.

The report’s specific findings include:

* Multiple pesticides are often found in California waters and sediments at concentrations that exceed levels that are lethal to zooplankton, the main food source of young fish.

* Most species of fish and zooplankton in the San Francisco Bay-Delta estuary have experienced dramatic population declines in the last 25 years. Toxic contaminants, especially pesticides, are known to be one of the factors contributing to these declines.

* Toxic pulses of two organophosphate insecticides, diazinon and chlorpyrifos, occur routinely in California streams and rivers during critical stages in fish development. The Sacramento and San Joaquin rivers as well as many creeks and sloughs in the San Francisco Bay-Delta estuary are specific areas with this problem. Urban creeks are also affected by these two chemicals, as pesticides applied around homes and gardens run off into creeks with irrigation water or storm water.

* The pesticides carbofuran and diazinon are responsible for the majority of bird kills in California, affecting many species of songbirds, waterfowl and raptors. Controlled studies have shown that when carbofuran is applied to crops, as many as 17 birds die for every five acres treated.

* Studies have shown that the frequency and number of bird kills in California closely parallels the agricultural activities that use pesticides most toxic to birds.

* Carbofuran applications to alfalfa, grapes and rice cause the majority of reported bird poisonings.

The report also reveals that pesticides are used routinely in national wildlife refuges, despite laws mandating that protection of wildlife and the environment take highest priority in these areas. In the Klamath Basin National Wildlife Refuge, pesticides that are toxic to wildlife are routinely used on potatoes, sugar beets, and onions grown within the refuge. In 1992, five bald eagles died from secondary exposure when the organophosphate terbufos was applied to sugar beets in the refuge. A new integrated pest management plan developed for the refuge still permits the use of a number of neurotoxic or endocrine-disrupting pesticides.

Some bird and fish species are already being impacted by pressures such as habitat loss. Disrupting the Balance warns that the deaths of even a few individuals from pesticides can push the entire species that much closer to extinction or prevent their recovery.

The report concludes with a chapter called “Restoring the Balance,” which provides a brief overview of ecologically-based pest management strategies that represent a long-term, sustainable solution to controlling pests without using toxic chemicals.

The report is available at

Hardcopies of the report are free to California residents and US$10 for all others.

Source/contact: Pesticide Action Network North America, 49 Powell Street #500, San Francisco, CA 94102; phone (415) 981-1771; fax (415) 981-1991; email; Web site



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