Using Rotenone to restore endangered fish may be endangering people

Gila topminnow

Using Rotenone to restore endangered fish may be endangering people…

But you won’t find out because some folks don’t want its use in Arizona waters — or any waters — subjected to review.

All that anyone is asking is, that before  dumping of this poison in public waters, human health impacts of Rotenone be carefully evaluated by credible, independent scientists  and  a public participation process be allowed.

There is strong opposition to reviewing the use of Rotenone in Arizona from state agencies and some individuals who will be paid to carry out these poisoning plans. They are joined by environmentalists and water projects with a vested interest in continuing the use of Rotenone.



For decades fish and game agencies have attempted to restore native fish and get rid of non-native fish in targeted streams and lakes. One common method is to use fish poisons – called piscicides – primarily Rotenone and Antimycin A. In many cases the same non-native fish being targeted for removal were originally stocked by fish and game agencies decades earlier.

Fisheries managers say Rotenone and Antimycin A have been used successfully to restore native, sometimes endangered, fish to their traditional habitats. They say without the poisons it would be impossible to reclaim streams for natives.

Opponents say fisheries managers don’t fully evaluate the risk of the piscicides to non-target aquatic species such as amphibians, reptiles, insects and macroinvertebrates, some of which may also be endangered. Using piscicides in pristine, headwater steams is especially troubling, and there are many who fear the cumulative impact the poisons may have on water quality and human health.

In most cases the repeated use of poisons hasn’t stopped non-natives and hybrids from reappearing in previously poisoned systems, either due to incomplete poisoning, natural migration, game department mistakes in stocking, and/or re-introduction of non-natives by citizens.

Kill all the exotic species so the native species can be restored….the Patagonia story:

Patagonia residents have had a very consciousness raising experience with this issue:



The situation started when the Coronado Forest Service made a “finding of no significant impact” (FONSI) on a proposal to dump Rotenone into a stream above the town of Patagonia’s water supply. The stated purposed was to kill all the “exotic species” in the stream such as mosquitofish so endangered native fish such as the Gila topminnow could be reintroduced.

According to 210 scientific studies, Rotenone is strongly suspected of triggering the onset of Parkinsons disease in people with a genetic propensity for Parkinsons.

Rotenone  is directly linked to the onset of Parkinson’s in those with a history of long-term exposure by recently released National Institute of Health Study (February, 2011).   Antimycin A, which is no longer manufactured in the United States and is banned from use in California because of human health concerns, has also been proven to be particularly destructive of macroinvertebrate populations and communities.

Patagonia derives its water from shallow wells and the potential for the Rotenone to get into the town’s water supply is extremely high.

Patagonia’s wells are only four miles downstream of the area slated for poisoning and because water moves rather quickly by subflow downstream from that area — especially after major precipitation events — when it takes as little as 6 hours to do so– the town wells are directly threatened. –

Back in 1997 when the California Game and Fish Department dumped Rotenone into Lake Davis, that actions polluted the town of Portola’s water source. The state of California ended up paying $9.2 million to replace Portola’s water supply.

But neither the Forest Service nor the Arizona Game and Fish Department, which is implementing the program to kill exotic fish and frogs,  gave due consideration to the growing body of scientific evidence pointing to the potential risk of Rotenone to the people of Patagonia.

The Patagonians organized a campaign to stop the Rotenone use that threatened the town’s water supply and  managed to get a bill introduced  by Senator Gail Griffin, who understands the moral and financial risk created by the application of this poison. The bill was quickly passed by the State Senate  (SB 1294). SB 1294 took the first step to stopping the poisoning of the streams  and water supplies in the state until there was a process to evaluate potential endangerment  of  human health.

The issue was raised to the state legislature: Do you want to risk the state having to replace Patagonia’s water supply? Do you want the moral or financial liability for triggering serious illness in Patagonia or in any other town impacted by Rotenone?

Arizona Game and Fish backed off its plan to poison the stream above Patagonia… for the moment.

Arizona Game and Fish has treated this  as an issue limitied to Patagonia. It is not. Plans exist to continue poisoning streams all over the state with Rotenone. Other communities’ water supplies are at risk.

This was the second  attempt  to poison the town’s water source  to exterminate the “exotic species” in the stream above Patagonia and the second time the town had to fight off the feds and the state and stop this  precipitous action.

But the advocates of Rotenone use have managed to stall the progress of SB 1294 in the State House of Representatives claiming Rotenone is not a threat and that Arizona’s sport fisheries are at risk .if this project is not carried out

“We had to burn the village to save it”

Remember that little gem from the Viet Nam war?

The most stunning fact that struck me about this fight was the idea that alleged “environmentalists” were eager to kill all the “exotic species” in the streams all over Arizona. Every mosquito fish, every bullfrog, every carp, bass, sunfish and whatever else  was living in the stream…dead.

I always though environmentalism was about protecting life.

So how could all these environmentalists  justify exterminating every living thing in a stream in the name of the environment?

This missive from Sally Stefferud, a long-time environmental activist, summarized her opposition to SB 1294:

The most urgent fish management problem in Arizona is incompatibility of native and nonnative fishes. Nonnatives have been introduced for a variety of reasons, and now threaten even the smallest and most remote remaining native populations. Control or removal of nonnative fish is a challenging problem with, at present, a very limited array of feasible tools. Innovative methods are being investigated at many levels of academia and government, but development is lengthy, technically difficult, and expensive (hundreds of millions of dollars). The most invaluable tools presently available are the piscicides rotenone and antimycin A. These safe chemicals have been effectively used for decades throughout the United States and other countries to manage fish populations.


A “calming” assertion, if you don’t take into consideration  this news dated February 15, 2011 from the Science News web site:  Two Pesticides — Rotenone and Paraquat — Linked to Parkinson’s Disease, Study Suggests

So maybe Rotenone isn’t all that safe as some claim….

The political and philosophical agendabehind the poisoning plan became obvious upon reading the defense of the stream poisoning scheme by the environmentalists involved. They make a sharp value  distinction between native species that naturally live in a place, and anything else that manages to co-habit with the native life.

There is “good” life and “bad” life.  Environmentalists want to kill all the “bad” (exotic) life so the “good” (native) life can be restored to some “pure” prior condition .

Even though there is growing evidence that dumping Rotenone into streams may endanger people downstream, the advocates of killing all the “exotic” life are really determined to get their way.

That raised an interesting question…why?

Turns out there is a complex relationship going on involving the Endangered Species Act, US Fish & Wildlife, litigious environmental groups such as the Center for Biological Diversity and state and federal agencies  involved in water projects or game management.

CAP , SRP and Arizona Game and Fish held hostage by Gila topminnow

The story starts in 1994 or 1995 when  US Fish & Wildlife and  environmentalists claimed fish could escape from the Central Arizona Project canals, swim upstream, and eat up and displace  native species (mostly minnows)  living in the headwaters of Arizona’s streams.

A “Biological Opinion” was issued by the feds (re-issued in 2008), claiming the native species were endangered by the water project. The Central Arizona Project was the crowning achievement of pioneer Senators and visionaries who saw a secure water supply as the lifeblood of Arizona. The environmentalists’ contrary view forced  the Central Arizona Project into an agreement with US Fish & Wildlife to mitigate the impacts of the  themuch needed water delivery system. 

Now, pursuant to the Biological Opinion, money from the CAP is generously dished out every year  to US Fish & Wildlife and others to poison Arizona’s streams to kill “exotic” species and replace them with endangered varieties of fish and frogs.

Millions of dollars have been spent and millions more are projected to be spent in this effort.

A lot of jobs are funded in the stream poisoning effort because the Arizona Game and Fish Department has a historic commitment to stocking lakes and streams with sport fish such as bass, trout, and catfish.  These edible fish, which are deemed by purists “exotic” problem species, so the Department finds itself obligated to “renovate” (poison) many miles of Arizona waters as expiation for its sportfish program.

US Fish and Wildlife and litigious environmental groups have the Department “over a fish barrel” with the CAP Biological Opinion. They are effectively prevented from continuing their stocking work unless they lead the poisoning and reintroduction efforts.

By Activists Rotenone is viewed as the only effective way to “renovate” the streams and restore the endangered species.

Sportsmen’s groups seem unaware that  environmental purists are just waiting for their chance to wipe out all stocking of “exotic” fish in lakes and streams…and even demolishing the dams that create the recreational lakes.  (Huge billboards in the Phoenix area once advertised their “blow up the dams” goal.)

One suspects that the Salt River Project’s behind-the-scenes opposition to SB1294 arises  from SRP’s fears that if the killing of exotic species in Arizona’s streams is halted…radical environmental groups could demand blowing up Roosevelt Dam and making the Salt River flow natural and free again (Note: radical environmental groups have repeatedly voiced their determination to see Glen Canyon Dam blown up).

The public needs to insist loudly that long-term effects of this poison be carefully analyzed before more people and aquatic species become experimental subjects in an increasingly questionable and clearly risky program.

The poisoning proponents dismiss concerns by stating that the poisons will be applied far from cities: oops, what about the rural residents? What about the effect on wildlife that drinks from those poisoned streams?

They want to keep poisoning our waters so they can “restore” native fishes….even if this approach doesn’t work, even if the poison has a record of frequently escaping from the targeted stream reaches, and even if there is a growing body of research suggesting substantial risk to people.

Some interesting articles:

From Scientific American’s website:

The Pesticide Rotenone: On the Shelf Instead of Shelved

According to the National Institutes of Health, pesticides are linked to Parkinson’s disease but not to worry. Really?

From Environmental Health News:

Health, ecosystem effects of rotenone ignored.

….Rotenone is a powerful neurotoxin that kills fish and other aquatic organisms by shutting down energy production in cells. Lab studies show that at low doses over time, rotenone selectively kills dopamine-producing nerve cells grown in petri dishes. Loss of these cells leads to Parkinson’s disease, and researchers routinely use rotenone to induce Parkinson’s disease in research animals. 

A few human studies have linked Parkinson’s disease with exposure to rotenone and other neurotoxic pesticides.  One study that looked at people living in Texas found significantly increased risk of Parkinson’s disease with any occupational or environmental use of rotenone in the prior year as well as an increased risk from using pesticides, including rotenone, during the last year while gardening.  

However, more studies in humans are needed to fully understand the health risks of rotenone exposure and to evaluate the sources of exposure after a waterway is doused.  At risk for exposure are people applying rotenone, anyone who may use treated water recreationally, and the general public if drinking water is contaminated following rotenone applications.

When the U.S. Environmental Protection Agency reviewed rotenone in 2007, it noted that, “using the existing database, EPA cannot quantitatively assess a potentially critical effect (neurotoxicity) at doses to which rotenone users could be exposed.” Essentially, neurological impacts of rotenone were not considered in EPA’s assessment, despite the fact that neurological impacts are the main issue of concern with rotenone. To account for this lack of information, EPA added a 10 times uncertainty factor to set approved concentrations for rotenone.

Importantly, rotenone has not been evaluated for effects on fetal development, although studies with other neurotoxins show that fetal exposure can increase a person’s risk for neurodegenerative disease, like Parkinson’s, later in life.

In his article, Jensen noted that there are “concerns about rotenone’s effect on invertebrates and whether the pesticide will persist in the creek beyond the few days a year projected by Fish and Game.” Hood writes, “Biologists have used rotenone for decades to eradicate fish and control their movement, and they say it is not believed to be dangerous to humans or wildlife.”

But when rotenone is applied to a river or lake with the intention of eradicating a target fish species, all fish, amphibians and invertebrates are vulnerable to extermination. Rotenone is not selective. Therefore, it is extremely dangerous to wildlife. Moreover, the loss of aquatic species eradicates the food supply for birds and other near-shore animals. This can interrupt bird diversity, nesting and reproduction for several years.

In addition to leaving out the health and ecosystem impacts of rotenone, neither journalist reported on whether or not rotenone actually works to achieve the fish eradication objectives set forth by water managers. 

In 1997, the California Department of Fish and Game applied rotenone to Lake Davis to control northern pike. Initially, the treatment worked, but two years later the pike returned.  

After the 1997 poisoning, the town of Portola had to switch its water supply from Lake Davis to wells due  to rotenone poisoning in the lake.  The debacle led to a $9.2 million settlement between California and Portola. Today, California continues to use rotenone against northern pike, despite the dramatic costs and ineffectiveness of this approach.

From the New York Times:

Calfironia Officials Tackle a Toothy Lake Predator 

PORTOLA, Calif., Sept. 11 – The poison didn’t work, and neither did the hook and bobber. The electrical probes were somewhat effective, but don’t even ask about the explosives.

The New York Times by Sara Bensinger

In support of the state’s eradication effort, residents in the Lake Davis area recently burned a 13-foot-long effigy of the pesky northern pike, made of papier-mâché with nails for teeth.

For the last decade, the state of California has waged a Sisyphean battle against the northern pike, a fish and a voracious eating machine. In the mid-1990s, when pike were first found in Lake Davis, a Sierra Nevada reservoir about four miles north of here, the discovery set off a panic over the potential impact on the local trout-fishing and tourist industries as well as the possibility of the fish migrating to fragile ecosystems downstream. Since then, millions of dollars and thousands of man-hours have been spent trying to spike the pike.

But while the methods, including poison, electro-fishing, explosives and decidedly low-tech nets, have varied, the results have remained the same.

“We’ve taken 65,000 pike out of the lake,” said Steve Martarano, a spokesman for the State Department of Fish and Game. “And we haven’t made a dent.”

But like Captain Ahab or perhaps Wile E. Coyote, the state has not let a little adversity stop it. On Monday, more than 500 fish and game personnel began a last-ditch, $16 million effort to rid the lake of pike, the most expensive ever undertaken against an “invasive species” in California. “This is a top-of-the-line predator,” said Ed Pert, the project manager. “If we don’t get it this time, we may need to rethink things.”

The lake was closed after Labor Day to prepare for the watery assault. The plan is simple: poison the fish with 17,000 gallons of rotenone, a commonly used pesticide that is absorbed through the gills and blocks the ability to process oxygen. Rotenone is widely considered safe for mammals and other nongilled animals, though some concerns have been raised about links to Parkinson’s disease and some types of cancer.

But Gerald Sipe, the director of environmental health for the Plumas County Public Health Agency, said his office had determined that the treatment plan would not adversely affect the public.

It is not the first time the state has used rotenone in Lake Davis. In 1997, officials used a powdered form of the poison, which fouled the lake, Portola’s longtime water supply. (The town now primarily draws its water from wells.) The state later approved a $9.2 million settlement with the city and the county for businesses, homeowners and local residents. And, two years later, the pike were back.


Senate Bill 1294 as passed by the State Senate:

Amending title 49, chapter 2, article 6, Arizona Revised Statutes, by adding section 49-311; relating to pesticide contamination prevention. 

 Be it enacted by the Legislature of the State of Arizona:

 Section 1.  Title 49, chapter 2, article 6, Arizona Revised Statutes, is amended by adding section 49-311, to read:

 49-311.  Application of aquatic poison

 A.  A person shall not apply Rotenone or antimycin A to any spring, seep, stream, river, stock pond, irrigation water delivery system, lake or any other body of standing or running water in this state, until submitting to the director a full impact analysis of any risks posed to the environment and downstream potable water supply or livestock water supply and receiving approval from the director for the application.

 B.  On receipt and review of the analysis, the director shall issue either a written approval if the director finds the application will not endanger the health of the environment, humans or livestock or a written disapproval of the analysis.

 C.  A person who violates this section is guilty of endangerment as prescribed in Section 13-1201.  


Note: Hugh Holub represents the town of Patagonia in this matter.

About Hugh Holub

Attorney and writer.
This entry was posted in endangered species act, environment, water and tagged , , . Bookmark the permalink.

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