On December 16, 2021, the Coastal Commission (“the Commission”) reviewed the U.S. Fish & Wildlife Service’s (“FWS”) proposed plan to disperse approximately 3,500 lbs (1.45 tons) of Brodifacoum-infused bait (rat poison) at the Farallon Islands - a globally significant and extraordinarily diverse marine ecosystem designated as both a Marine Protected Area and National Marine Sanctuary.

If permitted to proceed, bioaccumulation and the death of hundreds of animals, from birds and mammals to invertebrates, is anticipated to occur even if the project goes exactly as planned.

Recognizing uncertainty around the scope of the project’s risks, operative specifics, and mitigation plans, the Commission issued a Conditional Concurrence affirming the Project’s consistency with the California Coastal Management Program (“CCMP”) and its enforceable policies so long as certain conditions are met. However, these conditions have not been made public.

In a Public Letter highlighting an array of significantly understated risks, as well as serious omissions and inadequacies in the FWS’ prior studies, environmental and animal welfare advocacy groups are urging the Commission to re-open and revoke its Conditional Concurrence so that a more productive and transparent discussion prioritizing protection of California’s coastal resources can take place.

ISLAND ERADICATION: WHAT “SUCCESS” REALLY LOOKS LIKE

Mass animal casualties in the aftermath of island eradication projects have been reported around the globe (Video: Brodifacoum drops on Rangitoto and Motutapu Islands, 2009). In 2009, a similar project on Alaska’s Rat Island led to the reported deaths of more than 420 birds, including 46 bald eagles (Ornithological Council Report, 2009). During the Alaska Rat Island project, Island Conservation—the same organization involved in the proposed Farallon Island project at issue—dropped an amount of poison that was “in excess of that recommended by an advisory panel and probably above the legal limit approved by the US Environmental Protection Agency (EPA),” according to a 2011 Nature article.

Impacts on non-target species were similarly underestimated on Lehua Island, Hawaii, where invasive rodents were not eradicated after an initial aerial application, necessitating “mop-up” efforts of additional poison drops to effectively complete the project and ultimately resulting in the death of over 400 birds. Despite the unintended deaths, both projects were declared to be “success” stories as rodent eradication and rebounded population of the chosen island birds was accomplished.

While research regarding the accumulation and impact of rodenticides on marine species is limited, exposure through aquatic pathways is known to occur and residues have been detected in fish, mussels, and limpets up to three years after application. Such accumulations pose risks to species across the food web as well as to human health.

THE FARALLON ISLAND ECOSYSTEM

The Farallon Islands are located approximately 28 miles west of San Francisco in the Greater Farallones National Marine Sanctuary—a complex mega diversity hotspot nationally recognized as important breeding and feeding areas and home to at least 25 endangered or threatened species, 36 marine mammal species, including blue, gray, and humpback whales, harbor seals, elephant seals, Pacific white-sided dolphins, over a quarter-million breeding seabirds, and one of the most significant white shark populations on the planet. Positioned within the California Current, the area is one of the world’s four major upwelling regions known to host uniquely productive marine ecosystems driven by a combination of geological features, cold ocean currents, and surface winds.  

Considering the ecological complexity and regional importance of the Farallon Islands, the danger and potential widespread effects of poisoning are extremely concerning.

RISKS UNDERSTATED OR IGNORED BY FWS

The biological contents, movement, and/or stagnation of waters in the intertidal regions of the Farallon Islands were not properly assessed.

Intertidal ecosystems are an ever-evolving complex of plant, animal and micro-organism communities existing where ocean meets land (Mooney, H. & Zevaleta, E., 2016). These areas serve as haul-out areas for marine mammals as well as a source of food for a broad spectrum of species utilizing low and high tides. For example, fish move inshore to forage with higher waters, followed by seabirds arriving to hunt as tides recede (Intertidal, p. 343). Western Gulls, considered the most at-risk species to non-target poisoning are known to roost and feed in the intertidal zone during the fall when the proposed project is to take place (Consistency Determination, p. 47).

Wave-cut surge channels and sea caves in highly fractured and jointed granite rock are "major features of the intertidal zone on all sides of the Farallon Islands” (California State Water Resource Control Board (CSWRCB) p.16). The presence of these features is known to prolong exposure risks to grazing intertidal invertebrates (Primus et. al, 2004, p. 18).

Failure to consider the challenges that the complexities of the intertidal landscape pose to successful project implementation could lead to irreversible consequences with regional implications.

The Final Environmental Impact Statement (FEIS) wrongly concludes that there are no land crabs or similar species on the South Farallon Islands (FEIS p.155).

Despite reporting that no land crabs or similar species were found on the islands, the Striped Shore Crab, a semi terrestrial, grapsid species was found in the upper intertidal zone and has been recorded on multiple occasions: Point Blue Monthly Report, July 2021; Los Farallones blog, February, 2021; and several monitoring surveys (Roletto, 2014, SWRCB, 1979).

Land crabs have been identified as a risk factor in eradication projects because they are known to consume and collect large amounts of rodenticide bait pellets (Griffiths, R., and Miller, A., 2011; Samaniego-Herrera, et al., 2019). While direct effects of rodenticide consumption are uncertain, they may be secondary sources of exposure for other species (Griffiths, R., et. al., 2015). Burrowing crabs are also known to take and cache bait in their burrows (Samaniego-Herrera, et al., 2019).

Failure to consider the impact of land crab species on bait uptake and secondary poisoning could impact the probability of success, leading to demands for more poisons - and more risks - in subsequent rodenticide drops.

The size, length, conditions, and biological contents of the Farallon Islands’ caves are not described in the FEIS, nor any other publicly available project document.

The integrity of subterranean ecosystems involves an interactive relationship between land, water and air. Interference is likely to have undesirable impacts, and should be subjected to thorough environmental assessment. Considering the anticipated need for hand-baiting and/or traps within caves and areas of human habitation totaling up to 12 acres (FEIS p. 65 and 68), these details are essential to the public’s understanding of risks, collateral consequences, and the project’s likelihood of success.

The absence of information regarding caves and their possible interconnectivity, especially those with submerged or partially submerged entrances is alarming to say the least.

The Farallon Camel Cricket: Discrepancies in population data and trends for the Farallon Camel Cricket (Farallonophilus cavernicolus), a known consumer of bait pellets, raise serious concerns regarding risks associated with this species ingesting rodenticides.

As conduits that move nutrients from the surface of caves to the interior in the form of guano, Cave Crickets (members of the Rhaphidophoridae family) are considered to be a keystone species and essential components of a subsurface ecosystem. The Farallon Camel Cricket is found only in this single location. Because of its singular location, if the population size of this Cricket is as small as initially counted in 2010, the loss of even a few individuals could be detrimental to the species’ global population, as well as many organisms dependent on the organic subsidies they provide. If population numbers are higher, as subsequent counts seem to suggest, there may be a higher likelihood of other species - including the endemic Farallon Arboreal Salamander - ingesting this cricket as part of their natural diet and therefore increasing the risk of secondary poisoning.

Considering the endemicity of the Farallon Camel Cricket to this single, isolated location, and their essential function in the understudied subterranean ecosystems at the Farallon Islands, arthropod/island predator interactions and the biological characteristics of this species must be better understood before this Project is permitted to proceed.

The Farallon Arboreal Salamander: Specific data regarding the current population size and trends for the Farallon Island Arboreal Salamander (Aneides lugubris farallonensis)—a rare subspecies known only to occur on the Farallon Islands—are not found within the FEIS, nor any other published source.

As a lungless amphibian, salamanders breathe through their permeable skin and membranes, making them particularly sensitive to chemical contaminants (USGS). The well-being of the Farallon Island Arboreal Salamander is of particular concern considering the essential role amphibians play in the ecosystem, their susceptibility to chemicals and disease, and endemicity to this single, isolated location (Bralower, T. and Brice, D., n.d.) (Amphibia Web).

FWS claims that the potential for impact to the Farallon Arboreal Salamander population is “not significant” (FEIS 4.5.6.1.4, p. 191, and p. 257). However, results of study conducted as a part of the current project proposal suggest otherwise (FEIS 2.8.12 p. 150).

The FWS further insists that the project will benefit the Farallon Islands Arboreal Salamander by removing predation pressure from mice and by reducing competition for invertebrate prey (FEIS Section 1.3.4). If this is the case, it is hard to understand why House Mouse management efforts by Point Blue, the sole Farallon partner of FWS, have been so minimal. According to Point Blue’s 2019 Farallon Islands Ecosystem Report, trapping sessions have only been conducted in monthly 3-6 day sessions from August until trapping success is less than 10% for two consecutive sessions. Mitigative and/or preventative measures beyond these efforts are never mentioned and appear to be considered unnecessary as further demonstrated by suspension of trapping after March 2019. This was justified by a lack of need for further monitoring since data from previous years was “sufficient to characterize the annual cycle and interannual differences in overall abundance.” (p.16)

Failure to effectively reduce, manage, and prevent a rodent infestation on the Farallon Islands over Point Blue’s 50-year tenure suggest that protecting these species, and this ecosystem, are not the primary priority of this organization. While it appears that Point Blue has conducted meaningful observations and analyses over these years, an unwillingness to share its data, including basic population statistics, is concerning.

The long-term use of toxic chemicals at the Farallon Islands has been downplayed in documents provided to the public and the California Coastal Commission.

The use of toxic chemicals at the Farallon Islands has been underway for decades despite years of research demonstrating detrimental effects on plant, animal, human health, and aquatic resources. According to a FWS presentation delivered to the California Invasive Plant Council in 2017, herbicides—primarily glyphosate, i.e., RoundUp—are applied to the entire island 2-3 times per year. In fact, a 2005 narrative report boasted 17 years of RoundUp spraying. According to the report, approximately 538 gallons were applied in that year.

Given the persistence of glyphosate in soils (up to 428 days), the extended use of RoundUp at the Farallon Islands, and the quantity of rodenticides proposed for this project, failure to consider possible interactions and adverse outcomes demonstrates the inadequacy of the EIS and the risks it purports to assess.

DTA and its partners stand behind the biodiversity in danger at the Farallon Islands and implore the Coastal Commission to reject the proposed eradication project so that more humane, effective solutions can be explored and implemented. The known and unknown risks of this project are substantial and should not be ignored given the regional importance of this ecosystem and its surrounding waters. Join us by signing the Petition in support of our Public Letter to the California Coastal Commission

Our work would not be possible without the generous donations we receive. Help us continue defending ecosystems like the Farallon Islands and their inhabitants for generations to come. Please consider giving today.