EPA’s Biological Evaluation of Rodenticides is Green Wash for Island Eradications

The Endangered Species Act requires that the Environmental Protection Agency (EPA) conduct biological evaluations (BE) of the impact of pesticides on threatened and endangered species protected by the ESA.  For example, when the EPA published its final evaluation of glyphosate in 2021, it informed us that glyphosate is “likely to adversely affect” 93% of legally protected endangered and threatened plants and animals.

Source: EPA Biological Evaluation for Glyphosate

The EPA published a draft of a biological evaluation (BE) of 11 rodenticides in November 2023, which is a free gift to the island eradication industry.  The deadline for making comment on this draft is February 13, 2024.  Public comment can be made HERE

The EPA’s biological evaluation for rodenticides reached the conclusion that rodenticides used in island eradications have “no effect” on any aquatic plant or animal, including birds in the aquatic food web and amphibians with a fully aquatic lifestyle.  They made this “no effect” determination without evaluating any of those species, based on their claim that the Product Label for the rodenticide used in island eradications prohibits its use in water, which is not true.  EPA also extended this “no effect” determination to all species under the jurisdiction of National Marine Fisheries Services.  (1)

In fact, the standard Product Label for brodifacoum does not explicitly prohibit the use of the product in water.  It merely warns of the deadly consequences for aquatic species if used in water:  “This product is extremely toxic to birds, mammals, and aquatic organisms.  Predatory and scavenging mammals and birds might be poisoned if they feed upon animals that have eaten bait. Runoff may be hazardous to aquatic organisms in water adjacent to treated areas.  DO NOT contaminate water when disposing of equipment wash water or rinsafe.”  The standard Product Label also explicitly allows aerial broadcast of rodenticides for island eradications.  (2)  In other words, it’s dangerous to apply rodenticides to water, but, in fact, it often happens during island eradications.  The biological evaluation asks the public to believe the EPA’s claim that rodenticides are not used in water despite ample evidence that rodenticides land in water during aerial broadcasts on islands.

Although the standard Product Label acknowledges the potential that rodenticide runoff “may be hazardous to aquatic organisms in water adjacent to treated areas,” EPA’s biological evaluation dismisses that possibility by claiming that “use patterns preclude spray drift and runoff exposure.”  EPA’s biological evaluation provides no evidence in support of that claim and that claim is explicitly contradicted by the EPA in its evaluation of the proposed island eradication on the Farallon Islands as well as the considerable record of contamination of the aquatic food web during completed island eradications, as explained below.

Supplemental Product Labels are required for island eradications because they require greater quantities of rodenticide bait than allowed by standard Product Labels and modifications in application methods. The Supplemental Product Label required for island eradications explicitly permits the use of brodifacoum on water (3):

  • Elevated and floating bait stations are allowed in intertidal zones above the mean low tide mark and below the mean high tide water mark.
  • Broadcast applications are allowed in coastal areas above the mean high tide water mark.  Conversely broadcast applications are prohibited below the mean high tide water mark. 

The cited Supplemental Product Label for Wake Island was recently published in preparation for a second attempt to eradicate rats on Wake and 2 adjacent islands.  The first attempt in 2012 was a failure.  Here is a photo of this complex of islands:

Wake Island. Source: NASA

As you can see, Wake Island is a narrow strip of land surrounding a lagoon that is open to the ocean.  Two-thirds of the island is surrounded by sandy, tidal beaches.  Scrub vegetation is in the intertidal zone.  A portion of the island’s vegetation is wetland.  It defies belief that it is possible to aerial broadcast rodenticide from helicopters (or float bait boxes in the intertidal zone) on Wake Island without getting rodenticide in the water. 

The published study about the failure of the first attempt to eradicate rats on Wake Island was written by the organizations that conducted the project.  It reports that rats were found on the island less than a year after the aerial broadcast and supplemental hand-applications were done. The study makes no mention of non-target deaths of any animals.  The study speculates that the failure of the attempt was the result of not applying the rodenticide everywhere rats were living.  They will soon try again, using the same methods.  Rodenticide bait will surely end up in the water.  More non-target animals will undoubtedly be killed.  But the public will not learn about either of those issues, because the monitoring and reporting is entirely controlled by the perpetrators of these projects. (4)

Keep in mind that there are 239 taxa living in the intertidal zone around the Farallon Islands, according to Appendix J of the Final Draft of the Environmental Impact Statement for the proposed Farallon Islands.  No Supplemental Product Label has been granted yet for the proposed island eradication on the Farallon Islands, but the Farallones are included on the list of 29 island eradications (below) in the EPA’s biological evaluation, which the BE says will be done within the next 5-7 years.

Source: EPA Biological Evaluation of Rodenticides

Contamination of the aquatic food web during island eradications is inevitable

EPA made a public record of its concerns about contaminating the aquatic food web during island eradications in its letter of December 9, 2013 regarding “EPA comments on the Revised Draft Environmental Impact Statement for the South Farallon Islands Invasive House Mouse Eradication Project.” (5)  In response to the claims of the DEIS for the proposed island eradication that “the bait deflector will minimize, and in several places, prevent bait drift into the marine environment,” the EPA said, “The EIS should be clear that bait drift would occur.”

The EPA’s letter of December 9, 2013, goes on to report previous experience with aerial broadcast applications on Palmyra Island and states:  “For future operations, the potential for bait to enter the marine environment must be a factor in the aquatic risk assessment and further methods to minimize the amount of bait entering the marine environment should be fully explored. The amount of bait that enters the aquatic environment from an aerial broadcast depends on shoreline configuration, island topography, overhanging vegetation, bird activity affecting flight lines, wind strength and direction, weather conditions, and pilot experience. On islands where these factors increase the potential for bait to enter marine environments, additional mitigation measures may be needed to protect sensitive marine environments.” (5)

Based on those concerns about contamination of the marine food web, the EPA’s letter of December 9, 2013 expresses these specific concerns about the proposed aerial broadcast application on the Farallon Islands:  “Discuss and consider the factors that increase the potential for bait to enter marine environments that are identified above. Especially relevant are the irregular shoreline, the excessive bird activity from gulls, and the proposal to fly steep areas a second time (shorelines on the Farallones are steep) to increase the application rate in these areas.” (5)

Given the EPA’s explicit admission that aerial broadcast of rodenticides on islands have contaminated the marine food web in the past and are likely to do so in the future, the EPA is not in a position to now categorically deny that “use patterns preclude spray drift and runoff exposure,” as it attempts to do in the draft biological evaluation.  Nor is the EPA in a position to categorically deny that aquatic species will be adversely affected by rodenticide bait that will inevitably land in the water surrounding the Farallon Islands, as it attempts to do in the draft biological evaluation.

Farallon Islands, NOAA

The deadly track record of island eradications

The aerial application of rodenticide to kill rats on Anacapa Island in 2001-2002 was the first of its kind in North America. The project was complicated by the need to spare a population of endemic native mice on Anacapa.  Over 1,000 native mice were captured before the aerial application of rodenticide and released back on the island after the poison was no longer effective. Clearly, mice aren’t considered a problem on islands, unless they have the bad luck of being non-native.  Whether native or non-native, they are prey for many bird species.

Most of the raptors on Anacapa were removed before the rodenticide drop.  Of those that were left behind, 3 barn owls, 6 burrowing owls, and a kestrel likely died from rodenticide bait or eating poisoned mice.  94 seed-eating birds were also found dead after the poison drop.  The study says that these collateral kills were consistent with other similar projects.

Bird scavengers such as gulls, vultures, and condors are also vulnerable to secondary poisoning by poisoned rodents.  Shortly after the Anacapa poison drop, dead seabirds washed up on the shore near the Santa Barbara harbor.  UC Santa Barbara’s daily newspaper said“…a strong correlation exists between the National Park Service’s most recent airdrop of pesticide on Anacapa Island and the dead birds.”  These deaths weren’t reported by the study of the success of the poison drop.  As usual, the study was done by supporters of the project, with little interest in finding more collateral death from the drop.  The public is not allowed to observe island eradications.  Therefore, the public’s only source of information is those who are directly involved in the aerial application of rodenticides. 

“In October 2008, two helicopters dropped approximately 46 metric tons of Brodifacoum 25-W bait on Rat Island’s 2800 hectares, supplemented by hand application of bait around the island’s freshwater lakes. This rodenticide is known to be highly toxic to birds. Some nontarget mortality was expected, but the actual mortality exceeded the predicted mortality. Forty six Bald Eagles died (exceeding the known population of 22 Bald Eagles on the island); toxicological analysis revealed lethal levels of brodifacoum in 12 of the sixteen carcasses tested. Of the 320 Glaucous winged Gull carcasses, toxicology tests implicated brodifacoum in 24 of the 34 tested. Carcasses of another 25 bird species were found; of these 54 individuals, three were determined by necropsy to have died of brodifacoum poisoning.” (6)

Palmyra Atoll was aerially broadcasted twice with brodifacoum rodenticide in 2011 as well as a follow-up hand broadcast application.  The study of that project reported:  “We documented brodifacoum residues in soil, water, and biota, and documented mortality of non-target organisms. Some bait (14–19% of the target application rate) entered the marine environment to distances 7 m from the shore. After the application commenced, carcasses of 84 animals representing 15 species of birds, fish, reptiles and invertebrates were collected opportunistically as potential non-target mortalities. In addition, fish, reptiles, and invertebrates were systematically collected for residue analysis. Brodifacoum residues were detected in most (84.3%) of the animal samples analyzed. Although detection of residues in samples was anticipated, the extent and concentrations in many parts of the food web were greater than expected.”

These published studies are helpful to understand the scale of water contamination and collateral deaths of non-target animals, including aquatic animals.  However, they are just the tip of the toxic iceberg because little monitoring and testing is done on the many marine animals that have been killed in proximity of these projects.  Robert Boesch is a retired pesticide regulator for the EPA and the Hawaii Department of Agriculture.  Presently, he is Visiting Colleague at University of Hawaii at Manoa.  He has written an unpublished discussion paper (7) that reports:

  • Strandings of whales, some hemorrhaging, occurred within 60 days following anticoagulant bombardment.
  • Unusual mass strandings of hemorrhaging dolphins occurred in San Diego and Hawaii years after anticoagulant bombardment.
  • There is very little known about the fate of anticoagulant residues in the oceans.
Source:  Robert Boesch discussion paper available HERE
.

The documented deaths of non-target animals caused by island eradications are direct poisonings by eating bait on the ground or by secondary poisoning by eating poisoned rodents.  The EPA biological evaluation attempts to dismiss the potential for secondary poisonings by citing a study (Baldwin 2021) that claims most rodents die in their burrows after eating the poison, making them unavailable to be eaten by other animals.  This study is not relevant to island eradications because it was conducted on ground squirrels (not rats or mice), it used a first generation rodenticide (diaphacinone) which is not used in island eradications, and most applications were burrow baits, rather than aerial broadcast. 

What’s at stake?

About 1,200 island eradications have been done all over the world over the last 30 years, with mixed success. The EPA’s biological evaluation announces the intention to approve 29 new island eradications in US waters within the next 5-7 years, including the Farallones.  In the case of Hawaii, the list says “all islands.”  Many of the listed islands are actually a complex of islands, such as those in Boston Harbor. Many of the islands are residential communities, such as Nantucket and Martha’s Vineyard. As presently drafted, the biological evaluation will make it possible to approve those projects without addressing the considerable evidence that these projects are killing thousands of birds and animals and contaminating the ocean surrounding island eradications.

The Bottom Line

The draft biological evaluation is unacceptable because it gives the public the false impression that island eradications with rodenticides are harmless, when they clearly are not. It confers EPA’s blessing on island eradications by refusing to evaluate endangered species that may be harmed by island eradications.  It ignores the evidence that rodenticide applications have killed many terrestrial and aquatic animals and contaminated the water.

The biological evaluation must be revised to correct these flaws in the present draft:

  • Exposure to rodenticides during island eradications must be based on Supplemental Product Labels for island eradications, not standard Product Labels that do not apply to island eradications. 
  • The revised biological evaluation must evaluate all legally protected animals exposed to rodenticides during island eradications, including aquatic animals.  Both bioconcentration and bioaccumulation must be considered in the determination of exposure to rodenticides.  “No effect” cannot be assumed without such evaluation.
  • The revision must provide evidence in support of the claim that there is no drift or run-off of pesticide from aerial broadcasts done on islands or delete that claim, which is contradicted by actual experience with island eradications. 
  • The revision must remove the claim that rodents die in their burrows after eating rodenticide bait (Baldwin 2021) because the study was done on a different animal, using a different rodenticide, and a different application method. 

Update:  The final version of the EPA biological evaluation of rodenticides is unchanged from the draft.  It continues to make “no effect” determinations for all aquatic species and critical habitats under the jurisdiction of the National Marine Fisheries Service.  It continues to list the same off-shore islands (including the Farallons) where “APHIS is planning to conduct rodent eradication projects for the benefit of seabirds and other wildlife on these islands in the next five to seven years.”

The only changes it acknowledges making are the removal of some of the mitigation measures from the draft.  December 9, 2024


  1. EPA Biological Evaluation of Rodenticide
  2. Label Amendment for Brodifacoum -25W Conservation, November 12, 2019
  3. Supplemental Label for second attempt to eradicate Polynesian rates on Wake Atoll following previous attempt in 2012, December 6, 2021
  4. “The Wake Island Rodent Eradication: Part Success, Part Failure, but Wholly Instructive,” Island Conservation, et.al., Proc. 26th Vertebr. Pest Conf. Published at Univ. of Calif., Davis. 2014
  5. “EPA comments on the Revised Draft Environmental Impact Statement for the South Farallon Islands Invasive House Mouse Eradication Project.” December 9, 2013
  6. “The rat island rat eradication project:  A critical evaluation of nontarget mortality,”  prepared by The Ornithological Council, December 2010 
  7. See attached file:

Deadly Dogma:  Revisiting the Farallon Islands Unnecessary Eradication Project

“The more we know about plans to eradicate harmless mice on the Farallon Islands with rodenticide, the less sense it makes.” – Conservation Sense and Nonsense

Plans to eradicate mice on the Farallon Islands with rodenticide were approved by the California Coastal Commission (CCC) two years ago, on December 16, 2021.  Although CCC approval was contingent on a few conditions intended to reduce the inevitable death of non-target birds and marine animals, it is unclear if CCC will be able to enforce the conditions. Plans seem to be moving forward behind closed doors, so Conservation Sense and Nonsense continues to be concerned about this project. 

First a brief reminder of the project and our objections to it.  House mice were introduced to the Farallon Islands over 100 years ago by ships visiting the island.  There is no evidence that mice harm birds on the Farallons.  The mice are an integral part of the food web, eating primarily vegetation and supplementing that diet with insects during summer months when vegetation is sparse.  The mice are also the prey of hundreds of thousands of birds that live on the islands as well as birds that stop over on their migratory routes.  The mouse population varies throughout the year, dwindling during winter months and increasing in the fall.  When the mouse population declines, food sources for their predators also decline.  That’s when burrowing owls are said to prey on the nestlings of ashy storm petrels.  Though the mice are blameless, the project proposes to kill them all based on the assumption that burrowing owls will not overstay their migratory stop over if food sources are significantly reduced.  The project is expected to kill hundreds—perhaps thousands—of non-target birds who will eat poisoned pellets directly and/or poisoned mice.

The project has always seemed absurd and nothing we’ve learned about it in the past 2 years has made it seem otherwise.  Our last article of 2023 will report new information learned since the project was approved.

Contamination of the food web

Robert Boesch is a retired Pesticide Regulator for the Environmental Protection Agency, region 9 and the Hawaii Department of Agriculture.  Presently, he is Visiting Colleague at University of Hawaii at Manoa.  Based on his research and experience, he has written a discussion paper about island eradications using rodenticides, which he has shared with the California Coastal Commission and many other agencies and organizations.  This entire discussion document is available below as a footnote and this is his summary of “Eradication Programs Eliminating Invasives and their Predators and Scavengers!”

  • Eradication programs for mice and Polynesian Rats are planned for the Farallon Islands, Midway and Wake Island.
  • Brodifacoum, a potent, persistent and bioaccumulative anticoagulant poison is the toxicant. [This is the rodenticide that will be used on the Farallon Islands to kill mice. There are no rats on the Farallons.]
  • Brodifacoum residues have been detected in almost all fish that were collected following treatment of Palmyra, and trace levels were found in 10 percent of the fish after treatment of Wake.
  • Brodifacoum residues in fish caught at Wake increased from trace levels to detectable residues over 3 years.
  • Diphacinone is a greater threat of secondary poisoning to mammals than brodifacoum.
  • Strandings of whales, some hemorrhaging, occurred within 60 days following anticoagulant bombardment.
  • Unusual mass strandings of hemorrhaging dolphins occurred in San Diego and Hawaii years after anticoagulant bombardment.
  • There is very little known about the fate of anticoagulant residues in the oceans.

Our knowledge of contamination of the food web caused by rodenticide drops on islands is limited because monitoring is usually short-term and frequently done by the same contractors who implemented the project, with little motivation to report the extent or persistence of contamination.  For the same reasons, we have limited knowledge of how successful the projects are.

Track record of island eradications

About 1,200 island eradications have been done all over the world over the last 30 years.  Our evaluation of the proposed project on the Farallon Islands is based on the success or failure of those projects.

The aerial application of rodenticide to kill rats on Anacapa Island in 2001-2002 was the first of its kind in North America.  The project was also unique because it was complicated by the need to spare a population of endemic native deer mice on Anacapa.  Over 1,000 native mice were captured before the aerial application of rodenticide and released back on the island after the poison was no longer effective.  Although post-project monitoring reported successful eradication of rats, they were not confident that all of the mice that were left on the island had been killed. (1)

Attempts to eradicate mice have been consistently less successful than attempts to eradicate rats.  A study of 139 attempted eradications of animals on 107 Mediterranean islands in eight countries found that eradication projects targeted 13 mammal species. The black rat was the target of over 75% of the known attempted eradications in the Mediterranean Basin. The most widely used technique was poisoning (77% of all eradications), followed by trapping (15%) and hunting (4%).  Techniques were largely target-specific.

The average failure rate of the projects was about 11%, but success was defined only as the death of animals living on the islands at the time of the project. However, this percentage varied according to species. The failure rate of house mouse eradication was 75%. Reinvasion occurred after 15% of eradications initially considered successful. (2)

Island eradications considered initially successful, are often failures in the long run.  A recent visitor to Anacapa Island has reported seeing two dead rodents as her escorted group was leaving the island. One was identified as a deer mouse. The other rodent was not identified. Have rats returned to Anacapa?  Are native deer mice still being killed by residues of rodenticide? (3)

The eradication of rats on Anacapa Island is relevant to the planned project on the Farallon Islands because rats were killed, but mice were saved.  Although the Anacapa project considered rats a threat to birds, it did not consider mice a problem.  Rats were killed, but mice were saved by trapping and removing them from the island before the rodenticide was dropped.  Mice on the Farallon Islands are not a threat to birds.  They will be killed only because they are non-native.

Mice are members of the food web

Mice on the Farallon Islands are as much a part of the food web as they are on Anacapa Island.  They are prey of the birds and they are mainly predators of vegetation.  On the Farallon Islands, mouse predation of vegetation is considered a problem, but on Anacapa Island it is not considered a problem.  On the Farallon Islands, the study of the diet of mice reports that mice also eat insects when vegetation becomes scarce in the fall.  (4)

The study of the mouse diet on the Farallons also reports that 63%-80% of the vegetation on the Farallons is non-native.  That’s why Roundup (glyphosate) has been used on the Farallon Islands every year since 1988.  Between 2001-2005, an average of 226 gallons of herbicide were used annually (5.4 gallons per acre per year), according to the annual report of the Farallon National Wildlife Refuge. (5)

I took this photo on Santa Cruz Island in 2010, while visiting with an escorted group.

The Farallon Islands have never been inhabited and there has been no public access to the islands for over 100 years.  Non-native plants were not brought to the Farallons by humans.  Their seeds were brought by birds in their stomachs, in their feathers, on their feet and by wind and ocean currents.  Non-native plants dominate vegetation on the Farallons partly because non-native plants are eaten by birds.  The plants are members of the food web and their eradication is depriving birds and other animals in the ecosystem of food.  If non-native plants were not being eradicated with herbicides, it probably would not be necessary for mice to eat insects, which are not their preferred food.  We can safely assume that herbicides are harmful to the animals that consume plants that have been sprayed. (6)

Consequences of fiddling with the food web

There were also feral cats on the Farallons before they were killed.  Predictably, the population of mice increased after the cats were killed.  When 6,000 feral pigs were killed by sharp shooters on Santa Cruz Island, Golden Eagles substituted for that plentiful food source by preying on the rare, native Channel Island Fox.  Golden Eagles were captured and relocated to the mainland.  The fox population was restored to the island by a captive breeding problem.  The same could be done on the Farallons to eliminate the only known threat to ashy storm petrels.  The small population (approximately 6-10) of burrowing owls that are the only known predators of the petrels could be trapped and removed to the mainland as the Golden Eagles were on Santa Cruz Island.

Restoration plans for any ecosystem should begin with a thorough analysis of the food web.  Plucking single species of plants and animals out of complex ecosystems without understanding their role in the food web results in unintended and harmful consequences.

The Farallons project is based on mistaken assumptions

The Farallons project is based on the mistaken assumptions of invasion biology.  Most of the vegetation on the island is being killed with herbicide because it is non-native.  The vegetation is clearly essential to all the animals living on the island, but invasion biology asks us to believe that it is not, solely because it is non-native.  If the mice are killed on the island, it is only because they are non-native, not because they are harmful to birds.  They are an important source of food for the birds, but invasion biology asks us to believe they are not, solely because they are not native.  These assumptions are wrong, yet 50 years of nativist ideology still has a death grip on our public lands. 

This deadly dogma is losing its grip, but apparently too slowly to prevent the destruction of the food web on the Farallon Islands.  I always attend the conferences of the California Invasive Plant Council (Cal-IPC) and the California Native Plant Society (CNPS) to give native plant advocates every opportunity to convince me of their ideology.  Consistently, I find more support for my contrarian viewpoint than I do for invasion biology.  A presentation about the salt marsh harvest mouse at the Cal-IPC conference in October 2023, is an example.

California Department of Fish and Wildlife collaborated with UC Davis to study the food preferences of salt marsh harvest mouse (SMHM), an endangered native animal that lives in the wetlands of the San Francisco Bay. It has always been presumed to be entirely dependent on native pickleweed for food and habitat. The legally mandated recovery plan is based on that mistaken assumption.

Presentation to California Invasive Plant Council conference in October 2023

The study reported to Cal-IPC shows clearly that SMHM is NOT dependent on pickleweed for either food or habitat. SMHM is an extreme omnivore. SMHM ate 39 species of native and non-native plants as well as insects in empirical trials. In fact, it ate EVERY plant it was offered. A fecal study of SMHM living in the wild confirmed that finding. Fecal analysis found SMHM had eaten 48 native and non-native plant genera as well as some insects.

Presentation to California Invasive Plant Council conference in October 2023

SMHM have no preference for native plants for either food or nesting habitat. The most SMHM’s captured in the study were found where there was less than 10% pickleweed.

This was an absurdly simple experiment in which SMHM were captured and fed a variety of plants. It could have been done by anyone with little knowledge or fancy equipment. Why does this foolish mistake, caused by nativist bias, matter? Because “restoration” projects all around the San Francisco Bay have been eradicating non-native plants, claiming it would benefit the endangered SMHM.

For example, the spartina eradication project has been hunting for and poisoning hybrid spartina marsh grass for nearly 20 years, as well as planting pickleweed for SMHM. Since herbicides are used to kill non-native plants before pickleweed is planted, there’s little doubt that SMHM populations were harmed by the eradication of their food and shelter, if not directly harmed by the pesticides that are used.

Nativism in the natural world is not benefiting wildlife. Rather it seems to benefit only the army of “restorationists” who earn their living killing harmless plants and animals.  As long as they continue to receive public funding for their projects, they have job security because they have spent over 20 years trying to do something that cannot be done. Evolution moves inexorably forward. The puny efforts of humans to regress landscapes to arbitrarily selected historical standards cannot change the forward trajectory.

There were two presentations about difficulties with native plant restorations on Anacapa and Santa Rosa Islands at the CNPS conference in October 2022.  More than 20 years after non-native iceplant, rabbits, and rats were killed on Anacapa, native flora and fauna are still described as degraded, “Due to the cumulative and severe impacts to the soil and native seedbank, native vegetation communities have not recovered on their own…”  On Santa Rosa Island the “restoration” community has installed artificial fog fences to replicate a historical cloud forest to improve survival of native chaparral plants. (7)

Alternatives to rodenticide drop on Farallon Islands

It is not necessary to kill mice on the Farallon Islands because they are not harmful to birds.  If non-native vegetation weren’t killed with herbicides, there would probably be enough vegetation for omnivorous house mice as well as birds.  Both mice and vegetation are being killed only because they are non-native.  If the nativist ideology were removed from the agenda, dumping rodenticides on mice and herbicides on non-native vegetation would not be necessary.

If the protection of ashy storm petrels really were the goal of the proposed project on the Farallon Islands, the most obvious solution would be to remove the small population of burrowing owls that are the only known predators of the petrels.  Keep in mind that ashy storm petrels are not considered threatened or endangered and that two applications for protected status have been denied. (8)

There is a non-lethal alternative to reducing populations of rodents using rodenticides that kill non-target birds and other animals.  Academic scientists at Arizona State University have developed birth control for rodents that can be used on the Farallons to reduce the population of mice.  (WISDOM Good Works)

In Summary

Killing house mice on the Farallon Islands with rodenticide is unnecessary and will be harmful to the ecosystem and its inhabitants because:

  • Aerial dropping 1.5 tons of rodenticide will poison the entire ecosystem, killing hundreds of non-target birds and marine animals.
  • House mice on the Farallon Islands do not need to be killed because they are food for birds and they are harmless.
  • If burrowing owls are killing nestlings of ashy storm petrels, they could be removed and relocated.
  • The nearly 40-year attempt to kill non-native vegetation with herbicide should be stopped because the vegetation is a vital element in the food web of the Farallon Islands.

Happy Holidays and thank you for your readership.



  1. https://www.cambridge.org/core/journals/oryx/article/eradication-of-black-rats-rattus-rattus-from-anacapa-island/F1E46767D0EEC9A6357D414DD84ABE28
  2. https://onlinelibrary.wiley.com/doi/abs/10.1111/mam.12190
  3. https://myricopia.com/2023/11/21/anacapa-island-conservation/
  4. https://www.biorxiv.org/content/10.1101/2022.02.23.481645v1.full
  5. https://drive.google.com/file/d/1XoPcS104SeOUIyfbPT_NbardctNyWAgs/view
  6. https://www.nrdc.org/sites/default/files/opinion-glyphosate-20220617.pdf “As to ecological risk, it finds potential risks to animals and plants and ‘requires’ mitigation in light of those risks, laying out specific language for glyphosate product labels.”
  7. https://www.nps.gov/chis/learn/nature/cloud-forest.htm
  8. https://www.endangeredspecieslawandpolicy.com/u-s-fish-and-wildlife-service-denies-endangered-species-act-protection-for-ashy-storm-petrel

https://wisdomgoodworks.org/2023/10/611/

It’s time to comment on the deadly project on the Farallon Islands

US Fish and Wildlife proposes to aerial bomb 1.5 tons of rodenticide on the Farallon Islands to kill mice that do not harm birds, as explained in articles published earlier by Conservation Sense and Nonsense.  The California Coastal Commission declined to approve the project in 2019.  At the request of US Fish and Wildlife, the California Coastal Commission will reconsider the Farallon Islands project at their meeting on December 16, 2021.  It’s time to make your opinion of this project known to the Coastal Commission.  The Environmental Impact Statement for the project explains the project and its anticipated impacts. 

Click on this pictures of the Farallon Islands to see a video prepared by the Ocean Foundation about the islands and the proposed project.

Below is my message to the Coastal Commission. Beyond Pesticides has also provided a sample comment letter that is available HERE.   Please consider sending your own comment to the Commission here: EORFC@coastal.ca.gov. The deadline to send a written comment is 5 pm, Friday, December 10, 2021.  You can also submit a request to speak on agenda item 11b at the meeting HERE.   The deadline to request to speak is 5 pm, Wednesday, December 15, 2021. 


Update:  The project on the Farallon Islands that will aerial drop 1.5 tons of rodenticide to kill mice that have lived there for over 200 years was approved by the California Coastal Commission on December 16, 2021.  Speakers in opposition to the project did an outstanding job.  Jane Goodall recorded a message against the project.  The vote was 5-3.  Doubtful Commissioners asked some excellent questions and did not receive clear answers from US Fish & Wildlife.  As the meeting wore on over 7 hours, the project made less and less sense.  https://www.sfchronicle.com/climate/article/California-Coastal-Commission-approves-mouse-16709056.php


Dear California Coastal Commission, 

Please take my comments into consideration when evaluating the proposed project on the Farallon Islands.  I hope the Coastal Commission will confirm their lack of support of the project at your December 2021 meeting.

Thank you for your consideration.

Public Comment on Farallon Islands project

I am opposed to the plans to aerial bomb rodenticides on the Farallon Islands to eradicate mice for several reasons:

  • The project admits that hundreds of non-target birds will be killed by the rodenticide, either directly or by eating poisoned mice.  In September 2020, California banned the use of the rodenticide that will be used by this project because of the deadly impact on non-target wildlife, yet an exemption was created that will enable its use by this project.  The promoters of this project cannot deny that hundreds, if not thousands of non-target animals will be killed by this project.  That outcome is now confirmed by California State Law and by similar projects elsewhere in the world.   
  • The EIS clearly states that mice are not harming birds or chicks, the claimed beneficiaries of this project.  The EIS clearly states that a small population of burrowing owls is blamed for eating birds and chicks of other bird species. Removing the owls from the Farallon Islands is the non-toxic solution to the perceived problem. Yet, “…translocation of burrowing owls in lieu of eradicating mice was not considered as an alternative.” (pg 47)  The EIS then contradicts itself by offering translocation as mitigation for anticipated collateral bird mortality: “Migrant species including burrowing owls would be transported off the island released into suitable habitat on the mainland.” (pg 73)  Translocation is possible, but eradicating non-native mice is clearly the objective, not protecting bird species.  The mice are prey to many bird species.  Their loss will harm birds, not help them.
  • The food web on the Farallon Islands has not been adequately studied.  The project plan reports that the mice are a source of food for burrowing owls.  However, the project plan has not identified all of the predators of the mice.  Therefore, the project has not evaluated the extent to which the entire food web would be disrupted by the elimination of a major source of prey for birds of prey.  All predators of the mice are at risk of eating the poisoned mice and being killed by the poison.  Details on that issue are provided below.

These are the inadequacies of the EIS for this project:

Resident Burrowing Owls should be removed from Farallon Islands

The owls are the predators of the ashy storm petrel, not the mice.  Therefore, the owls are the obvious target for removal.  Given their small number relative to the large population of mice, their removal would be easier and less deadly to every animal living on the islands. 

This strategy was successfully used by the National Park Service to save the endangered Channel Island Fox on the Channel Islands.  Golden Eagles were not considered “native” to the Channel Islands.  They arrived in the 1990s because of feral pigs and goats that had been introduced to the islands.  When NPS took over management of the islands, they removed the feral pigs and goats, but not the Golden Eagles.  Deprived of the food the eagles came for, the eagles turned to preying on the Channel Island Fox, nearly driving it to extinction.  From 1999 to 2006, the eagles were trapped and moved off the island: “In order to mitigate golden eagle predation on island foxes, The Santa Cruz Predatory Bird Research Group, with the support of the Park Service and The Nature Conservancy, relocated golden eagles to distant sites on the California mainland. A total of 44 golden eagles, including 10 eaglets born on the islands, were trapped and relocated, and monitoring indicates that none have returned.” NPS considers the removal of eagles the primary factor in saving the Channel Island Fox from extinction.  The 44 birds that were removed were more than 4 times more numerous than the 8-10 burrowing owls on the Farallon Islands.  They are enormous carnivorous birds, compared to the pint-sized, ground-dwelling burrowing owls. 

Please note that the threat to the fox posed by Golden Eagles was created by the removal of the prey of the Golden Eagles without adequate analysis and understanding of the food web.  NPS should have predicted that the loss of the preferred prey of Golden Eagles would disrupt the food web in ways that could have been predicted.  Now other “experts” are poised to make a similar mistake at the expense of thousands of rare birds and marine mammals on the Farallons.

The Madrone Chapter of Audubon Society in Santa Rosa opposes this project and agrees that relocation of burrowing owls is “feasible and could be planned and carried out.”

Disrupting the Food Web

The EIS has not adequately analyzed the food web on the Farallon Islands and has therefore not identified the environmental impact of eradicating an important source of food for the animals that live on the island. 

This depiction of a fresh-water aquatic food web is an example of the complexity of food webs.  The food web on the Farallon Islands is probably very different, but remains largely unknown because the EIS does not analyze it or describe it.  Source:  Creative Commons-Share Alike

According to the EIS, there are many birds of prey on the Farallon Islands, most migrating, but some resident:  falcons, hawks, kites, eagles, owls, and kestrels. Most of the migrating raptors are on the island in the fall, when the mouse population is at its peak.  The EIS acknowledges that the raptors probably eat mice on the island, but dismisses that as a significant issue. However, it would be a significant factor in evaluating environmental impact if migrating raptors compensate for the loss of mice as their prey by preying on birds or salamanders.  The EIS does not address the important question of what birds of prey will eat if mice are eradicated. 

Given that mice are expected to survive for 21 days after being poisoned, and the poison is expected to be effective for over 100 days, it is more likely that many birds of prey will be killed by eating poisoned dead or dying mice. The number of days the rodenticide is expected to be effective exceeds the known limits of hazing effectiveness. For that reason, the EIS says the project will “attempt” to capture raptors present on the island prior to and during bait application.  An unsuccessful “attempt” will result in the death of raptors.

There are also many animals living on the Farallons that could eat the poison or the poisoned mice, but not killed by the poison, such as invertebrates and Dungeness crabs.  Although they are not killed, they would be contaminated by the poison they eat and become killers of the animals that eat them, such as birds and marine mammals. 

The EIS states that many of the insects that live on the Farallons are detritivores that feed on decomposing carcasses, such as the poisoned mice.  Then they become killers of the warm-blooded animals that eat them.  The Farallon Islands are located within the Dungeness crab fishery.  If they are contaminated by poison pellets or fish, they could become killers throughout the fishery.  According to the EIS, “Adult crabs are opportunistic feeders, but prefer clams, fish, isopods and amphipods. Cannibalism is common. Several species of predators feed on Dungeness crabs, especially the pelagic larvae and small juveniles, including octopuses, larger crabs and predatory fish such as salmon, flatfishes, lingcod, cabezon and various rockfishes. They are numerous in offshore areas of the Gulf of the Farallones, and support one of the most productive fisheries in California.”

A similar mistake was made by a rat eradication project on the Palmyra atoll.  The first attempt to eradicate the rats in 2002 failed partly because Palmyra’s abundant land crabs outcompeted the rodents for the poisonous bait. The crabs’ physiology allowed them to eat the poison—the anticoagulant brodifacoum—without ill effect.  The reason why this attempt failed was that the “experts” who designed this poison drop did not realize that the rats lived in the coconut palms and didn’t spend much time on the ground.  In other words, the poison wasn’t dropped where the rats lived.  The second drop was delivered to the crowns of the palms:  “The crowns became a convenient platform for stashing cotton gauze sacks of poison bait, delivered by workers firing slingshots or dangling from helicopters.”  This project is now focused on eradicating 30,000 adult palms and over 2 million juvenile palms from Palmyra using herbicide.  These island eradications have repeatedly demonstrated that they are not successful and they ultimately put land managers on a perpetual pesticide treadmill.   The result is a poisoned environment that is dangerous to every living plant and animal on the island.

Ironically, the explosion of the mouse population on the Farallons was the unintended consequence of inadequate understanding of the food web:  “House mice and other animals such as cats and rabbits were introduced to the island when ships landed there in the 19th century. While the cats and rabbits have been removed, the mice population has exploded to an estimated 60,000, or about 500 mice per acre.”  One of the primary predators of the mice was removed, which resulted in increased population of their prey, the mice.  Now USFWS proposes to eradicate the prey, which will have unintended consequences, such as the death of the predators who will eat the poisoned mice, or the predators of the mice eating bird eggs and chicks instead, or predators not having adequate food, or all of the above.   

Rodenticides are known killers of birds of prey

This article published by Beyond Pesticides explains how birds of prey are killed by rodenticides:  “While a rodent is likely to die from this poison, ingesting it also turns it into a sort of poison Trojan horse for any predator that may take advantage of its slow decline. An eagle that eats a poisoned rodent at the edge of death will be the next to succumb to the anticoagulant effects ‘Humans need to understand that when those compounds get into the environment, they cause horrible damage to many species, including our national symbol, the bald eagle,’” said the scientist who conducted a study of eagle deaths that found: “‘The vast majority of bald and golden eagles in the United States are contaminated with toxic anticoagulant rodenticides, according to research published earlier this month.’” We know that 46 bald eagles and over 420 seabirds were killed by the rat eradication attempt on Rat Island in Alaska, but we don’t know how many more were contaminated with rodenticide and are handicapped by sub-lethal effects. 

Source: Beyond Pesticides

Temporary Results

One of many reasons the mouse eradication project on the Farallon Islands is controversial is that similar projects all over the world are not successful.  Some are not successful in the short run and are immediately done again. Lehua is one of the Hawaiian Islands on which extermination was attempted and failed.  An evaluation of that attempt was published in 2011 to determine the cause of the failure so that a subsequent attempt would be more successful.  That evaluation included this report on the success of similar attempts all over the world:  “An analysis of 206 previous eradication attempts against five species of rodents on islands using brodifacoum or diphacinone is presented in an appendix to this report. For all methods, 19.6% of 184 attempts using brodifacoum failed, while 31.8% of 22 attempts using diphacinone failed. The Farallons project plans to use brodifacoum. 

Some are not successful in the long run.  Rodenticides were aerial bombed on the Lord Howe Islands in Australia in 2019 at a cost of $16 million. Two years later, two rats (one male and one pregnant female) have been found.  Genetic tests will determine if they arrived from elsewhere or are descendants of the original population. An article in The Guardian explains the elaborate effort on Lord Howe to find new rats and exterminate them.  This strategy might work on an inhabited island, such as Lord Howe, but it is not an effective strategy on the Farallons because it is not inhabited, has only occasional visitors, and its steep, rocky terrain is not easily monitored.  New mice or rats could be undetected on the Farallons long before anyone would know it. 

This is an example of one of the fundamental truths of the “restoration” industry:  The work is NEVER done.  It must be done repeatedly.  The cost is daunting, the collateral damage to non-target animals often unacceptable, the results only temporary.  The cost-benefit ratio is unfavorable.

Ethical considerations

For the record, I would like to clearly state my objection to the Farallons project.  I consider it unethical to kill one species of animal based on a presumed benefit to another animal species.  In this case, the chosen scapegoat is considered a non-native animal that has lived on the Farallon Islands for nearly 200 years and is therefore fully integrated into the food web.  There are hundreds of thousands of sea birds and mammals living on the Farallons.  They are the best testament to the fact that mice have not been harmful to birds and other animals on the Farallons.

Hundreds of non-target animals will be killed by this project because of the toxicity of the rodenticide and the random manner in which it will be applied on the island.  The project will clearly do a great deal of harm to all life on the Farallons and its benefits are obscure at best. Please do not endorse this pointless, deadly project.   


“The mouse eradication project on the Farallon Islands: The ‘con’ in conservation”

We are republishing the following article published by Huffington Post on January 7, 2013, with permission of the author, Maggie Sergio.  Maggie has done some impressive research about the appalling project to aerial bomb the Farallon Islands with rodenticides to kill mice.  We shudder to think about how many other animals will be killed by this project.  Please sign the petition to US Fish and Wildlife to abandon this horrible plan.  The petition is available HERE.

*************************************************

I first heard the term “island eradication” back in 2011, when a colleague sent me an email that contained a project scoping notice from U.S. Fish & Wildlife (USFWS), San Francisco Bay National Wildlife Refuge Complex. This public notice announced a non-native mouse eradication project for the Farallon Islands, which are located 27 miles off the coast of San Francisco. The solemn tone of his words — “Have you seen this?” — quickly caught my attention.

As I read the document I couldn’t believe what was being contemplated. USFWS wants to use helicopters to drop 1.3 metric tons of brodifacoum (in the form of loose rat poison pellets) over the Farallon Islands, an area that has been designated as a National Wildlife Refuge. Nonnative mice are the issue. The ashy storm-petrel, a seabird that is considered a species of special concern, is being indirectly impacted by the presence of mice.

Photo of ashy storm-petrel courtesy of Wikipedia images. Photo taken by Duncan Wright
2014-01-04-ASPDWrightresize.jpeg

It is Fish and Wildlife’s assumption that the population of the ashy storm-petrel, a bird that is naturally a slow breeder, would recover if the mice could be eliminated. The rationale being used is that the mice are the food source that attracts an average of six burrowing owls–which also eat petrels–to the Farallon Islands every year. USFWS scientists believe the burrowing owls are staying longer than they normally would if the mice were not there. It is believed that the owls show up to feast on the mice when the mouse population spikes during the fall and early winter. The burrowing owl is also a species of special concern.

Photo of burrowing owl courtesy of Wikipedia images. Photo taken by Dori Merr
2014-01-04-BurrOwlresiz.jpg
When the mouse population dips during the winter months, the few burrowing owls that remain on the island can, and do, turn to eating the chicks of the ashy storm-petrel. In reading the data provided by USFWS, I found it very interesting that out of 1,618 prey items analyzed in 679 owl pellets, only 82 storm-petrels were found. Based on the data from USFWS the majority of the owls’ diet appears to be invertebrates and mice.

It is important to add that the owls are not the only animals consuming the ashy storm-petrel chicks. Western gulls, one of the most opportunistic birds I have ever worked with as a wildlife rehabilitator, also consume ashy storm-petrel chicks. I can’t help but wonder when the Western gulls or any other species on the Farallones will be targeted next by USFWS in this unsettling fable of environmental ethics that pitches one species of animal against another.

If this 1.3 metric ton poison drop is allowed to move forward, thousands of wild animals will be inhumanely poisoned, and in turn, those killed become a poisoned food source for other animals. This is how the food web becomes contaminated. Since USFWS is chartered with the mission to protect ALL living resources within the public trust, the casual tone conveyed by this agency regarding collateral damage and “non-target species” is deplorable and unacceptable. I reached out to USFWS and asked for a comment with respect to that mission and how this project is contradictory. I have yet to receive a response.

There is also the potential for long term damage to the environment. Sub lethal impacts of anticoagulant rodenticides on wildlife are a threat that has the potential to impact future generations of birds, fish, sea lions, elephant seals, raptors, sharks, insects, crabs and other marine life. If the poison does not kill them outright, it can affect their behavior, reproduction, and survivability. Information on sub lethal poisoning was completely bypassed in the revised draft environmental impact statement (RDEIS) released this past October. Page 139 contains the statement that “Adverse effects as a result of possible sub-lethal exposure are unknown for brodifacoum or diphacinone.” The EPA also makes mention of this omission on page 11 of their 18 page comment letter found here

Information on sub lethal impacts of anticoagulants is readily available to anyone with access to the internet and web browser. This report tells the story of a dog exposed to brodifacoum at one point in her life, though her owners don’t know when, as this dog never displayed any acute symptoms of exposure. This dog was bred and the result was eight of her eleven puppies died soon after birth. Three were necropsied. Two of the puppies were found to be bleeding internally and brodifacoum was detected in the livers of two of the dead puppies. This is how brodifacoum and other anticoagulant rodenticides work. After animals ingest the poison, the animal bleeds to death because the active ingredient interferes with the blood’s natural ability to clot. This is the type of scientific documentation that is required to be disclosed in an environmental impact statement. The exclusion of this critical information equates to “cherry picking” of science. What happened to this dog has the potential to be replicated by a number of species that live in, or close to the fragile ecosystem of the Farallon Islands, if brodifacoum or other anticoagulants were to be aerially broadcast across the terrain.

Here’s the really scary thing. If this same event were to occur in nature as the result of brodifacoum permeating the food chain, the public and scientific community would not even be aware of it since the post project monitoring does not include monitoring for the presence of rodenticides or residues in the environment, except for intertidal invertebrates and then ONLY ‘If greater than negligible bait drift into the marine environment is detected.” (pg. 72 of the DEIS)

I started researching island eradication projects over two years ago and quickly learned of what happened on Rat Island in Alaska, a previous rodent eradication project that resulted in the poisoning of at least 46 bald eagles and over 420 seabirds. I found this highly critical report written by the Ornithological Council of USFWS and Island Conservation, and this story by Nature magazine.

I also received several emails urging me to investigate what was happening with the eradication project at Palmyra Atoll, which is located about 1000 miles from Hawaii. I have since learned that the eradication attempt at Palmyra Atoll resulted in bait getting into the water and fish becoming a contaminated food supply. The final report is available here.

first wrote about this topic for the Huffington Post back in 2011, after members of the public were denied the opportunity to make public comments at the first public scoping meeting held in Fort Mason, San Francisco in May of 2011. We were given a presentation by the officials about the problem of non-native mice on the island, and the indirect impact these mice were having on the ashy storm-petrel, the farallon arboreal salamander, and the caramel cricket. We learned that an environmental impact statement was underway and that USFWS had engaged with two partners for this project; Island Conservation and PRBO (now Point Blue Conservation Science). After a presentation on how these projects are carried out and why one is needed at the Farallon Islands, we were divided into groups and sent to separate corners of the large room. Without a doubt, this was a technique for crowd control. There was a healthy turnout of concerned citizens and most were shocked and opposed at the prospect of using helicopters to carpet bomb the Farallones with a type of rat poison (brodifacoum) that has come under heavy scrutiny from the EPA and the California Dept of Pesticide Regulation.

In each of the room corners were representatives from USFWS, Island Conservation and Point Blue Bird Science. They had flip charts and wrote down questions, concerns and suggestions. In speaking with one representative from USFWS, I raised the question of other animals being poisoned in the process, something continually referred to as “non-target species.” The response was casual and dismissive. “Nobody likes it, but it happens” one USFWS employee shrugged.

Conflict of Interest
Fast forward to the fall of 2013 and a 741 page Revised Draft Environmental Impact Statement (RDEIS) is released. Written by Island Conservation under two Cooperative Agreements found here, and here. The creation of the environmental impact statement netted the Santa Cruz based nonprofit a total of $481,883. Island Conservation is also the contractor that will get the eradication business if the decision is made to move forward with this project. And since Island Conservation is a registered 501c3, income earned from eradication projects is tax free. Details surrounding the financial relationship between Island Conservation and USFWS didn’t surface until I asked Gerry McChesney, USFWS Refuge Manager for the Farallon Islands, how much Island Conservation has been paid to write the environmental impact statement. My request was handled under the Freedom of Information Act.

The blatant conflict of interest is disturbing, but what angers me is that it took my questioning before this information became public knowledge. Island Conservation has been paid $481,883 by USFWS to write the environmental impact statement for an eradication project they will be awarded worth approximately 1.3 million dollars. This explains the end result of a highly biased and misleading environmental impact statement.

According to NEPA’s (National Environmental Policy Act) rules of engagement, financial interests of parties involved need to be disclosed in the environmental impact statement. This is something the EPA pointed out in their lengthy comment letter dated 12/09/13.

” In our scoping comments, we raised potential conflict of interest issues if Island Conservation were to prepare the impact assessment and also carry out the eradication project. Since the DEIS does not include the disclosure statement, required by 40 CFR 1506.5(c), specifying that Island Conservation has no financial or other interest in the outcome of the project, it is unclear whether this issue has been addressed.” ~ EPA comment letter on the Farallones mouse eradication project, 12/09/13

Speaking of the EPA…..When they write an 18 Page Comment Letter with Concerns, We Need to Listen

This letter dated 12/09/13 from the EPA identified the numerous issues the EPA has with the draft environmental impact statement. What is unfortunate is that the EPA has no jurisdiction to stop this project. Only to give opinion and point out any potential NEPA violations, such as the conflict of interest issue.

The tone of the EPA’s letter was serious and expressed great concern about this project moving forward. Points raised by the EPA include the fact that the amount of bait proposed for use violates federal law, that predictions with respect to the success of hazing of wildlife are overly optimistic and do not mention how hazing activities would affect the mice, and fails to include any information about the failures of several previous island eradication projects.

“Much information can be obtained from previous rodent eradication attempts and it is not clear that lessons learned from these projects have been integrated into the planning for the proposed project. We are aware that three recent rodent eradication attempts – Wake Atoll, Henderson Island, and Desecheo Island – have failed. These efforts all attempted to eradicate rat species. The Wake Atoll Rat Eradication Review concluded that planning and associated research did not seem to adequately address some of the key issues and the general complexities of the project, and that the number of information gaps noted during the planning process should have led to serious consideration of postponing the project until those issues were more fully addressed. This is our main concern for the Farallon project.” ~ EPA comment letter, 12/09/13

Retired USFWS Biologist Weighs In
Biologist Sonce DeVries recently retired from USFWS after 22 years. During her tenure as Acting IPM Coordinator from 2010-2012, she reviewed proposals for a number of island eradication projects. While she fully agrees that invasive species are an issue that need to be addressed, she feels strongly that the approach that has been used in the past by USFWS and Island Conservation is not the way to do it. Her six page comment letter found herereflects many of the same concerns I have regarding the inaccurate and misleading science behind this proposed project.

“My review of the references cited in this DEIS shows that some significant misinterpretations of the original references have occurred. The authors of this environmental impact statement must accurately quote the scientific literature and not insert words or phrases that imply or state a different conclusion from that of the original reference being cited. While the DEIS states that no choice of alternatives has been made, the text clearly indicates that the reader is being strongly encouraged to select Alternative B, the use of Brodifacoum as the preferred alternative. Well written EISs go to great lengths to present a completely neutral discussion of the facts and allow the reviewer to reach their own conclusions. The DEIS does not meet that requirement.” ~ Sonce DeVries, retired biologist and former Acting IPM Coordinator, USFWS.

The Ocean Foundation
Richard Charter is a Senior Fellow with The Ocean Foundation and Vice Chair of the Gulf of the Farallones National Marine Sanctuary Advisory Council. When it comes to protecting our oceans and marine life, Richard is a seasoned advocate on issues such as marine spatial planning and the prevention and mitigating of industrial impacts on ocean ecosystems. His environmental work has helped to create the Gulf of the Farallones, Cordell BankChannel Islands and the Monterey Bay National Marine Sanctuaries.

Richard has many concerns about the proposed project that he outlined in this four page comment letter here from the Ocean Foundation. Richard has a wealth of experience surrounding Natural Resource Damages Assessments (NRDA) and has requested that USFWS and/or Island Conservation post a surety bond in the event of accidental rat poison spills into the ocean (which occurred during a New Zealand project) and the inevitable deaths of non-target animals due to exposure to brodifacoum.

“The Revised DEIS is inadequate in reflecting a casual and dismissive attitude throughout the document regarding the inevitable mortality of public trust living resources, such as numerous non-target species, including birds and marine life, in a manner which hardly presents a fairly-considered cost-benefit analysis. Throughout the DEIS the document instead attempts to rationalize the unnecessary killing of a lot of innocuous wildlife in the process of eradication of one species – the mice – but the document provides no conclusive evidence that the Ashy Storm Petrel will benefit over the long term from all of this collateral damage throughout the overall ecosystem.” ~ Richard Charter, Senior Fellow, The Ocean Foundation.

American Bird Conservancy
American Bird Conservancy is the only bird conservation organization that hasn’t been drinking the USFWS/Island Conservation Kool-Aid about this proposed project. I think they are the only birding group that took the time to read and think critically about what USFWS wants to do. Below is a quote from the ten page comment letter submitted last month.

“American Bird Conservancy is concerned about the tenuous and indirect connection between the stated goals of the Project and the proposed means of achieving them. The conclusions in the RDEIS are founded on what we deem to be a faulty and incomplete analysis. We are concerned about poisoning the Farallon food web, including migrating raptors, sea birds, native terrestrial species, and marine mammals, and about what we consider an unacceptable level of projected incidental mortality of Western Gulls. We are also worried about the potential to cause long-term damage to the very practice of eradication of non-native mammals from islands. Related concerns include, but are not limited to, the inflated projection of effectiveness of gull hazing operations, the inadequate consideration of alternative methods of bait delivery, the biased selection of modeling assumptions, the exclusion of data from Rat Island, the under-estimation of brodifacoum toxicity, and the unorthodox and potentially biased risk assessment assumptions for diphacinone.” ~ George H. Fenwick, PhD, American Bird Conservancy

Dolphins and Penguins Die Following Drops in New Zealand
To better understand what happens with island eradication projects, watch this news report which tells what happened on two islands in New Zealand after brodifacoum was aerially dropped over two islands. Notice how Richard Griffiths with the New Zealand Department of Conservation dances around the repeated question with respect to the testing of dead dolphins and penguins for exposure to brodifacoum. Richard is now employed by Island Conservation.


Despite the critical data and the many voices of opposition, USFWS may still decide to move forward. My plea to USFWS is to remember the work of one of their own most influential biologists, Rachel Carson. Her revolutionary book, Silent Spring, published in 1962, sounded the alarm about the environmental impacts of pesticides and the penetrating influence the chemical industry has on commercial agriculture. Fifty two years later, the dominion of the pesticide industry continues and has now expanded beyond the confines of agriculture to include invasive species as another market opportunity to exploit. With respect to the South Farallon Islands Mouse Eradication Project, this is the “con” in conservation.


Update:  The Final Environmental Impact Statement for the mouse eradication project on the Farallon Islands was published on March 15, 2019.  The Final Environmental Impact Statement recommends the original plan as the “preferred alternative.”  In other words, despite intense opposition to this plan, its implementation is now eminent. 

No public comments are allowed on a Final Environmental Impact Statement, so there’s nothing further we can say about what seems to be an unnatural disaster in the making.  At this stage of a project, lawsuits are the only way to stop it.  I don’t know if anyone is willing and able to sue.