Clean Water for Salmon: An Elusive Goal


While we often hear that we are an over-regulated nation, the truth is that thousands of miles of salmon and steelhead streams continue to be subjected to contamination by hazardous pesticides, even though the National Marine Fisheries Service has determined that the legal use of these pesticides jeopardizes the survival of multiple runs.

(Featured in the January 2015 issue of The Osprey, A Journal Published by the Steelhead Committee & International Federation of Fly Fishers)

Despite years of effort to recover endangered and threatened Pacific salmon and steelhead, some of the most toxic pesticides still legal in America continue to enter their habitat.  Common-sense efforts to keep these pesticides out of streams, including stream buffers and foregoing application when soils are saturated, have been ordered by the foremost fish agency in the country - the National Marine Fisheries Service - but the Environmental Protection Agency (EPA) has yet to act on these recommendations.

Pesticides are ubiquitous in our modern world, with nearly a billion pounds of pesticides applied each year in the U.S., the majority in agriculture. Pesticides are designed to kill. Once these chemicals escape into the nation's rivers, they are nothing more than poisons to both fish and humans.

And escape into the waters they do.  According to the U.S. Geological Survey, which monitors surface waters nationwide as part of the National Water Quality Assessment Program (NAWQA), pesticides occur frequently at harmful levels in the nation’s rivers and streams.  Data gathered between 2002-2011 show that:

●      in agricultural areas, more than 60% of sampled streams contained pesticides that exceeded at least one chronic aquatic-life benchmark,

●      in urban areas 90% of streams contained pesticides exceeding at least one chronic aquatic life benchmark.[i]

In the Pacific Northwest and California, the unfortunate and unintended creatures at the receiving end include 17 runs[1] of salmon and 11 runs of steelhead listed as endangered or threatened under the Endangered Species Act (ESA).   Fish and other aquatic organisms are particularly vulnerable to pesticide contamination of water, since pesticides can be carried far downstream and aquatic organisms are immersed throughout their lives

What Harm Can Pesticides Cause to Fish or Their Prey? While the intended effect for the pesticide application may be eliminating fruit-boring insects in apples or preventing weeds in new fields of wheat, the toxicity inherent in pesticides (which includes herbicides as well as insecticides, fungicides, rodenticides, and wood preservatives) can pose direct harm to non-target organisms.  Even if aquatic areas are intentionally avoided, runoff, leaching, and even atmospheric deposition of pesticides from use sites can carry repeated doses of pesticides into streams. 

Fish and aquatic animals are exposed to pesticides in three ways (1) dermally, with direct absorption through the skin by swimming in pesticide-contaminated waters, (2) through breathing, by direct uptake of pesticides through the gills during respiration, and (3) orally, by drinking pesticide-contaminated water or feeding on pesticide-contaminated prey.

 Any of these routes of exposure can cause direct mortality in short time frames (acute toxicity).   This is the kind of poisoning that occurs with spills, which sometimes results in large fish kills.  Some of the most acutely toxic pesticides to fish or aquatic invertebrates include organophosphate pesticides (such as diazinon, malathion, and chlorpyrifos) and carbamate pesticides (such as carbaryl).  These are nerve poisons and act by disrupting nervous signals in animals.  Pyrethroid chemicals are also highly toxic to fish.  Pyrethroids mimic the mode of action of the plant-derived pesticide pyrethrin, but are much more toxic and persistent in the environment. They attach to soil particles and are washed into waterways on sediment.

Thankfully, the majority of pesticide contamination in salmon streams does not result in the immediate death of fish.  This does not mean, however, that salmon and steelhead are safe from pesticide effects.  Small "sublethal" doses of some pesticides can lead to changes in behavior, weight loss, impaired reproduction, inability to avoid predators, and lowered tolerance to extreme temperatures. Indirect effects can include changes in habitat, including a reduction in the abundance of prey species.  The overall consequences of sublethal doses of pesticides can be reduced adult survival and lowered populations.  This is a risky outcome especially for populations already depleted and stressed by other factors such as passage issues, warm temperatures, and presence of exotic fish.

Is Our Government Doing its Job to Keep the Water Clean?  It is the EPA’s responsibility to ensure that pesticide use doesn’t harm endangered species (see sidebar).  But unfortunately for salmon and steelhead, the EPA has failed the public trust.  In fact, EPA only began evaluating pesticide effects to listed Pacific salmon and steelhead after being sued in 2001 by a coalition of environmental and fishing groups, including the Washington Toxics Coalition, Northwest Center for Alternatives to Pesticides,[2] Pacific Coast Federation of Fishermen’s Associations, and Institute for Fisheries Resources.

The suit focused solely on 54 broad-spectrum and highly toxic pesticides, all of which had been found at levels higher than EPA’s own “aquatic life standards” in rivers on the west coast.   These 54 compounds were toxic to more than fish; many were documented as highly toxic to humans, bioaccumulative in human tissue, human endocrine disrupters, and/or known carcinogens or mutagens.

In 2002, the U.S. District Court ruled for the salmon, ordering EPA to initiate the Endangered Species Act evaluation process.  Interim no-spray buffers for the 54 chemicals along salmon-bearing streams (300 feet for aerial sprays, 60 feet for ground sprays) were ordered by the Court in 2004, at least until permanent protection measures could be devised through the consultation process. 

The Consultation Results

EPA’s initial assessment determined that 37 of the 54 pesticides “may effect” listed salmonids (a term that includes both salmon and steelhead). These 37 pesticides were submitted to NMFS for formal consultation under the ESA.

Since 2008, NMFS has been releasing Biological Opinions (“Biops”) for these 37 active ingredients in a series of “batch” consultations (pesticides are grouped where they have a common mode of action).  Of the 28 pesticides reviewed in completed Biological Opinions so far, a dismal picture has emerged, with the following results[ii]:

-       19 pesticides were determined to pose jeopardy (likelihood of extinction) to one or more salmon or steelhead runs.

-       21 pesticides were determined to pose adverse modification to the critical habitat of one or more runs 

-       The ESUs with the highest number of jeopardy calls are Chinook Salmon (Sacramento River winter and Central Valley spring runs) and Steelhead (Central Valley California, Central California Coast, and Southern California runs). 

Figure 1 shows the number of jeopardy and adverse modification calls for each chemical that has so far completed the consultation process.[3] 


Figure 2 shows the number of jeopardy and adverse modification calls by run. 


For each Biop with a jeopardy or adverse modification call, NMFS has included mitigation measures known as the Reasonable and Prudent Alternative (RPA) to prevent or mitigate pesticide harm, as required (see sidebar).  Interestingly, rather than recommend cancellation of these pesticides, these RPAs include more moderate measures such as:

➢      Drift and runoff buffers

➢      Application limitations when wind speeds exceed 10 mph

➢      Application prohibitions when soil moistures are already saturated or a storm event is likely in 48 hours following the application

➢      Reporting of all incidents of fish mortality

After 12 years of Analysis and Regulation, Aren’t Salmon Better Protected Now?

A citizen might expect that EPA would have followed the recommendations from NMFS, as the law requires.  In fact, EPA has NOT used its power under FIFRA to implement the RPAs or equivalent measures.  This not only bodes ill for salmonids but throws into question the whole meaning and purpose of federal endangered species law.

Much to the disappointment of the coalition of groups involved in the litigation, the buffers that were mandated while EPA completed the consultation process were eliminated once the Biological Opinions were complete.  The buffers were eliminated, even though the logical conclusion of the Biological Opinions – implementation of permanent protective measures as outlined in the RPAs – was never acted on by EPA.   

In addition, the process has unleashed pushback from the chemical industry.  The first Biop was challenged in court by Dow Chemical, and has been remanded to the NMFS for re-evaluation.

Other pushback has been in the form of proposed waivers from pesticide review in Congressional legislation.  For instance, in 2011, one version of the federal Farm Bill included a provision that would have prevented the EPA from taking actions to protect endangered species from harmful pesticides under the ESA, without the voluntary agreement of pesticide manufacturers. The same Farm Bill draft also included a clause that would have eliminated Clean Water Act protections as they apply to pesticides. 

The Good News

Thankfully, environmental and fishing groups have been monitoring the EPA and Congress and working steadily to uphold sensible pesticide policy.

For example, the Northwest Center for Alternatives to Pesticides and other groups[4] noticed EPA’s lack of action on the RPAs, and filed a complaint in federal court (through environmental law firm Earthjustice) asserting that this lack of action and the remand of the first organophosphate Biop amounted to illegal take of listed salmonids.  This action resulted in a settlement agreement in 2014, which reinstates the buffers where chlorpyrifos, diazinon, malathion, carbaryl, and methomyl are used adjacent to salmon-supporting waters.  These reinstated buffers will be in place until permanent protective measures are in place (or unless the new consultation process determines no adverse effect). 

Fighting back against chemical industry influence in the Farm Bill, the Pacific Coast Federation of Fishermen’s Associations submitted testimony warning that inclusion of these waivers would allow corporations a de facto veto over a federal environmental law and would substantially change existing laws “to elevate financial considerations above environmental protections… making future species recovery that much more difficult for other industries, including farming.”  The letter also pointed out that environmental protections for rivers and estuaries help protect fishing industry jobs and benefit the multi-billion dollar fishing industry.  This monitoring paid off; the bill passed without the damaging inclusions.[iii]

Other good news is that, since 2001, eight chemicals that were a part of the set of 37 pesticides submitted for consultation have been wholly cancelled, and an additional eight chemicals have had some uses cancelled or restricted.[5]  Most of these cancellations and restrictions have occurred in the organophosphate group, a particularly hazardous group of pesticides.  While some of these actions have occurred due to farmworker or drinking water concerns, salmonids benefit from the cancellations.

In Oregon, some members of the state Legislature are signaling their desire to move ahead in 2015 with a bill to increase buffer zones between spraying areas and drinking water and to increase the notification requirements for nearby residents.  This action follows on the widely reported incidents of overspray of rural residents and their water sources last year, involving some of the same compounds that NMFS analyzed in their biological opinions, such as 2,4-D and triclopyr.

Also in Oregon, a task force appointed by the Governor recently recommended reactivation of the state’s pesticide use reporting system (which has been defunded since 2009).  This system helps facilitate better understanding of pesticide use and assists with logical, sensible approaches for mitigating use risks.

What’s Next for Salmonids and Pesticides?

Under request by NMFS, EPA, and other federal agencies, the National Academy of Sciences (NAS) convened a committee to review the scientific and technical issues related to determining risks posed to listed species by pesticides.  The salmonid issue is not the only driver for this; EPA has been hit by a number of lawsuits related to its inadequate assessment of endangered species in its pesticide registrations.  In April 2013, the NAS Committee published their review of the risk assessment process and provided recommendations to EPA and the Services. 

A major conclusion of the committee was that the Services and EPA need a common approach to risk assessment.  Heartening to endangered species proponents, the NAS panel urged reliance on probability models in evaluating potential effects on threatened and endangered species, rather than the “risk quotient” approach EPA uses in the rest of its registration program. [iv]

In the short run, EPA will prepare a new biological evaluation on the effects of three organophosphate pesticides (chlorpyrifos, diazinon, and malathion) to ALL listed species nationwide.  A separate evaluation will address two carbamate pesticides (carbaryl and methomyl).  These biological evaluations are expected to be prepared over the next 12-24 months, with formal consultation with the Services (as needed) to follow.

What You Can Do

Ultimately, the process has revealed that it is foolhardy to assume that pesticide use in accordance with current pesticide labeling is sufficient to avoid impacts to listed species, including listed salmonids.  Over the long run, eliminating use of toxic pesticides, using them in ways that are proven to minimize impacts, and/or adoption of alternative, less-toxic means to manage pest problems will most protect salmon from toxic runoff. 

The Northwest Center for Alternatives to Pesticides (NCAP) and its partner organizations continue to watchdog the federal and state agencies and Congress on pesticide issues, and to advocate for effective pesticide regulation for protection of both community and environmental health. NCAP works with farmers and researchers to develop alternatives to the pesticides that are affecting salmon populations. Please refer to our website at for more information.

Consumers, farmers, and fish advocates can contribute to this work in many ways. 

1)    Practice low-impact approaches and seek alternatives to pesticides on your own properties as much as possible. 

2)    Support organic agriculture in your food buying habits. 

3)    Observe the legally mandated buffers adjacent to salmon-supporting waters (60 feet for ground applications, 300 feet for aerial applications) if you do apply chlorpyrifos, diazinon, malathion, carbaryl, and methomyl.  See the Salmon Mapper at

4)    Even if salmonids aren’t in your local water body, utilize effective buffers around streams, rivers, wetlands, and ditches to avoid the likelihood of pesticides reaching salmon streams. 

5)    Engage with the issues by joining NCAP’s advocacy efforts.  During public comment periods on federal actions lend your voice to the process by providing comments to the EPA, Congress, your associates, or the media.  NCAP posts actions you can take on our website at - check regularly for opportunities to take action.  Join NCAP’s email list. 


[1] Salmon and steelhead runs are also described as Evolutionarily Significant Units (ESUs).

[2] Formerly known as the Northwest Coalition for Alternatives to Pesticides

[3] The first Biop covering three chemicals (chlorpyrifos, diazinon, and malathion) was remanded back to NMFS for re-evaluation  after a successful suit by Dow Chemical.

[4] Other plaintiffs included the Pacific Coast Federation of Fishermen’s Associations, Institute for Fisheries Resources, Defenders of Wildlife, Joel Kawahara, Edward Deryckx, Northern California Council of the Federation of Fly Fishers, and Turtle Island Restoration Network

[5] Wholly cancelled active ingredients include:  carbofuran, molinate, methyl parathion, methidathion, disulfoton, methamidophos, fenamiphos, azinphos-methyl.  Partially cancelled active ingredients include:   chlorpyrifos, malathion, methomyl, diazinon, phosmet, ethoprop, dimethoate, and pendimethalin).


[i] Stone, W.W., Gilliom, R.J., and Martin, J.D., 2014, An overview comparing results from two decades of monitoring for pesticides in the Nation’s streams and rivers, 1992–2001 and 2002–2011: U.S. Geological Survey Scientific Investigations Report 2014–5154, 23 p.,


[ii] NOAA Fisheries.  Pesticide Consultations Summary and Schedule.


[iii] Pacific Coast Federation of Fishermen’s Associations.  Protecting Salmon from Pesticides, by Zeke Grader and Glen Spain.


[iv] National Research Council, 2013.  Assessing Risks to Endangered and Threatened Species from Pesticides.  National Academy of Sciences.  The National Academies Press:  Washington D.C.

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