CETOS' Critical Habitat Project Focuses on the Effects of Chemicals to California Salmon Populations

By Britt Bailey

One of the primary goals of the newly formed Critical Habitat Project of the Center for Ethics and Toxics is to assess the risks to endangered species, specifically salmon, from the impacts of pesticide applications in intensive farming areas. The project momentum is the result of prior consulting assignments where we established that a significant amount of pesticides exceeded the protective levels accepted for vulnerable aquatic species, such as endangered salmon.

One of CETOS' consulting assignments involved a partnership assignment with Smith River Project (www.smithriverproject.org). The Smith River, including its sloughs and estuaries, are home to perhaps the healthiest populations of salmon in the State of California. In fact, the Smith River is considered a State Reference Stream for salmonid populations due to these relatively healthy fish stocks. It is home to Central Coast Coho, northern California Steelhead, and the California Coastal Chinook. The Upper and Middle Smith River subwatersheds have been targeted as high priorities for watershed restoration. These areas (the Upper and Middle Smith River) comprise a “key watershed,” meaning it is an area important for maintaining and recovering habitat for at risk fish stocks, specifically salmonid populations and other resident species.

The Smith River estuary is especially important to the recovery efforts of salmon. Estuaries generally afford rearing, refuge, and feeding grounds for salmon. Juvenile salmon experience the highest growth rates of their lives while in estuaries and near-shore waters. Juvenile salmon move to estuaries for weeks or months to grow and adapt to salt water before moving out to sea. The estuary is the location where salmon transform from a freshwater to a saltwater fish. This adaptation, called smoltification, is especially sensitive to chemical disruption. Smoltification involves alterations and developmental changes to body chemistry, appearance, and behavior that are easily disrupted by toxic chemicals.

Degradation to the quality of water within the estuary is a significant barrier for the continued survival and recovery of salmon. Studies involving the effects of pesticides on salmon show that juvenile salmon may suffer adverse effects from passing through polluted estuaries and near-shore areas. Human-produced pollutants can cause immune dysfunction, increased susceptibility to disease and impaired growth and development in fish. Ecological impacts of some pesticides to non-target organisms, such as the effect of the carbamate pesticide carbofuron in male salmon, can lead to a significantly reduced ability to respond to priming pheromones, a scent released when a female is ovulating. Low level concentrations of fungicides have also been shown to cause death in juvenile salmon.

Although, the Smith River is recognized for its rich biological diversity, nearly 200,000 pounds of pesticides are used near the banks of the river’s estuary. As with estuaries generally, the Smith estuary acts as a nursery where salmon complete their maturation and ready themselves for life in the ocean. We assessed 5 chemicals used within the surrounding land intensively cultivated for lily bulbs—90% of the lily bulbs grown in the United States come from this small 11 square mile area. We discovered that of the five pesticides examined, 4 exceeded the levels of protection set by the EPA for endangered aquatic organisms.

More recently, CETOS in partnership with Californians for Alternatives to Toxics (www.alternatives2toxics.org) examined the levels of three pesticides (active ingredients only) used for 10 crops surrounding endangered and threatened salmon populations.

The four California salmon populations include Southern Oregon/Northern California Coho, Central Valley California Steelhead, South Central California Coast Steelhead, California Coast Chinook, and Southern CA Steelhead. Of the three chemicals (chlorpyrifos, carbaryl, and diazinon) used in 10 crops, nine of the ten crop areas exceeded the threshold of protection for salmon. What does It all Mean?

Our “findings” coupled with research on the policy and scientific data available from government agencies, point to shortfalls in the level of protection provided to the recovery efforts of salmon populations in California. In our view, the EPA has failed to consider key factors such as the effects small doses of pesticides can have on an organism’s behavior. Research on pesticides has shown low doses of pesticides can affect an animal’s ability to smell. For salmon, this sense is integrally linked to homing and alarm responses. Pesticides can also impact an animal’s reproductive capacity. For example, some pesticides can disrupt the swimming behavior of salmon, which in turn affects their ability to reach spawning areas.

The indirect effects of pesticides are also less than adequately understood. Pesticides can wipe out food sources creating alterations and indirect effects to habitat. An additional concern in addressing the effects of pesticides to endangered species is the extent to which a chemical can be assessed in a site-specific manner and in isolation of other activities.

CETOS' Critical Habitat Project is prepared to take a refined look at these and related pesticide endpoints. We have developed a way to estimate environmental risk concentrations of pesticides using site-specific data within actual established boundaries of the species population. The resulting assessments take into account the actual rate of use within a habitat. The so-called risk quotients provide an accurate way to estimate the potential risk to endangered populations from the active pesticide ingredient. Once an estimation of risk is established, we are determined to develop educational and policy programs that can assist in the recovery efforts of endangered and threatened species.