Aerial rodenticide drop on California’s Farallon Islands threatens ecosystem, comments expected

0

(Beyond pesticides, November 29, 2021) The US Fish and Wildlife Service (FWS) is re-launching its proposal to apply the toxic rodenticide brodifacoum by air (helicopter) to kill house mice on the Farallon Islands National Wildlife Reserve off the northern California coast. Globally significant wildlife populations inhabit the Farallones, including hundreds of thousands of seabirds and thousands of seals and sea lions. According to the FWS, these are: thirteen species of seabirds that nest on the islands, including Leach’s Oceanite, Ashfish, Fork-tailed Oceanite, Double-crested Cormorant, Brandt, Pelagic Cormorant, Black Oystercatcher, Western Gull, Common Murre, Common Murre, Cassin Starique, Rhinoceros Starique and Tufted Puffin; pinnipeds, including northern fur seals, Steller’s sea lions, California sea lions, harbor seals, and northern elephant seals that breed or strand at Farallon Sanctuary; and endemic species, including white sharks, greylag bats and arboreal salamanders.

Tell the California Coastal Commission to refuse the proposed aerial dispersal of the highly toxic brodifacoum rodenticide to the Farallon Islands.

Brodifacoum is a “second generation anticoagulant rodenticide” (SGAR) highly toxic to birds, mammals and fish. It also poses a risk of secondary poisoning to predators. The California Department of Pesticide Regulation quotes the FWS: “Secondary exposure to SGARs is particularly problematic due to the high toxicity of the compounds and their long persistence in body tissues. For example, brodifacoum, a common RAS, is persistent in tissues, bioaccumulates and appears to interfere with reproduction … Even in cases where the immediate cause of death has been identified as a car strike, predation or disease, toxicologists and pathologists have reached a sufficient toxicological level. evidence to conclude that rodenticide-induced blood loss increased animals‘ vulnerability to the immediate cause of death. The threat of secondary poisoning has led the State of California to prohibit the use of brodifacoum for almost all uses. Although this particular use is an exception, the risks of use are extremely high.

Aerial spraying of brodifacoum endangers the mammal and avian fauna of the Farallon Islands, as well as marine life which can be exposed when the poison washes or settles in the ocean. There is no way to limit the impact on the targeted house mouse. A 2015 study carried out after an airdrop of rodenticides on the island of Palmyra off the coast of Hawaii reported: “We have documented brodifacoum [rodenticide] residues in soil, water and biota; and documented mortality of non-target organisms. Some baits (14-19% of the target application rate) have entered the marine environment at distances of 7 m from the shore. After the start of the application, carcasses of 84 animals representing 15 species of birds, fish, reptiles and invertebrates were opportunistically collected as potential non-target mortalities. In addition, fish, reptiles and invertebrates were systematically collected for residue analysis. Residues of brodifacoum were detected in most (84.3%) of the animal samples analyzed. Although the detection of residues in samples was anticipated, the extent and concentrations in many parts of the food web were greater than expected.

Home to rare and endemic seabirds such as the Cinderella, the Farallon Islands certainly have a serious mouse problem – 59,000 rodents inhabit the rocky islands. Mice compete with native species for resources and attract an average of six burrowing owls per year. Owls prey on gray petrels when mouse populations decline during the winter, killing hundreds of petrels each year. The world’s population of Gray Oceanite is small (10,000-20,000), but it is not considered endangered.

As important as native ecosystems are, the application of a poison is a toxic and simplified solution to a complex problem that requires the wisdom of nature itself, as species evolve and adapt to new conditions. SEIS should investigate the possibility of controlling mice through intensified controlled predation by providing nesting boxes for barn owls and / or kestrels.

Tell the California Coastal Commission to refuse the proposed aerial dispersal of the highly toxic brodifacoum rodenticide to the Farallon Islands.

Letter to the California Coast Commission:

I ask you to reject the proposal to apply the toxic rodenticide brodifacoum by air (helicopter) to kill house mice at the Farallon Islands National Wildlife Refuge. Globally significant wildlife populations inhabit the Farallones, including hundreds of thousands of seabirds and thousands of seals and sea lions. These include: thirteen species of seabirds that nest on the islands; pinnipeds, including northern fur seals, Steller sea lions, California sea lions, harbor seals and northern elephant seals; and endemic species, including white sharks, greylag bats and arboreal salamanders.

Brodifacoum is a “second generation anticoagulant rodenticide” (SGAR) that is highly toxic to birds, mammals and fish. It also presents a risk of secondary poisoning to predators. The California Department of Pesticide Regulation quotes the FWS: “Secondary exposure to SGARs is particularly problematic due to the compounds’ high toxicity and their long persistence in body tissues. For example, brodifacoum, a common RAS, is persistent in tissues, bioaccumulates and appears to interfere with reproduction … Even in cases where the immediate cause of death has been identified as a car strike, predation or disease, toxicologists and pathologists have reached a sufficient toxicological level. evidence to conclude that rodenticide-induced blood loss increased animals’ vulnerability to the immediate cause of death. The threat of secondary poisoning has led the state of California to ban the use of brodifacoum for almost all uses. Although this particular use is an exception, the risks of use are extremely high.

Aerial application of brodifacoum endangers the mammal and avian fauna of the Farallon Islands, as well as marine life that may be exposed when the poison washes or settles in the ocean. There is no way to limit the impact on the targeted house mouse. A study conducted in 2015 after an aerial drop of rodenticides on the island of Palmyra off the coast of Hawaii reported: “We have documented brodifacoum [rodenticide] residues in soil, water and biota; and documented mortality of non-target organisms. Some baits (14-19% of the target application rate) have entered the marine environment at distances of 7 m from the shore. After the start of the application, carcasses of 84 animals representing 15 species of birds, fish, reptiles and invertebrates were opportunistically collected as potential non-target mortalities. In addition, fish, reptiles and invertebrates were systematically collected for residue analysis. Residues of brodifacoum were detected in most (84.3%) of the animal samples analyzed. Although the detection of residues in samples was anticipated, the extent and concentrations in many parts of the food web were greater than expected.

Home to rare and endemic seabirds such as the Cinderella, the Farallon Islands certainly have a serious mouse problem – 59,000 rodents inhabit the rocky islands. Mice compete with native species for resources and attract an average of six burrowing owls per year. Owls prey on gray petrels when mouse populations decline during the winter, killing hundreds of petrels each year. The world’s population of Gray Oceanite is small (10,000-20,000), but it is not considered endangered.

As important as native ecosystems are, the application of a poison is a toxic and simplified solution to a complex problem that requires the wisdom of nature itself, as species evolve and adapt to new conditions.

Please reject a conclusion of consistency of the proposed aerial dispersal of the highly toxic brodifacoum rodenticide on the Farallon Islands and demand that an additional environmental impact assessment (SEIS) be carried out by an independent body examining the alternatives, including the non-hazardous alternative. integrated non-toxic action and control methods. SEIS should investigate the possibility of controlling mice through intensified controlled predation by providing nesting boxes for barn owls and / or kestrels.

Thank you for considering this request.


Source link

Share.

Comments are closed.