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
One of CETOS' consulting assignments involved a partnership assignment
with Smith River Project
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
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
Although, the Smith River is recognized for its rich biological diversity,
nearly 200,000 pounds of pesticides are used near the banks of the rivers
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 bulbs90% 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
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
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 organisms behavior. Research on
pesticides has shown low doses of pesticides can affect an animals
ability to smell. For salmon, this sense is integrally linked to homing and
alarm responses. Pesticides can also impact an animals 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.