California's Farallon Islands--home to what scientists believe is the world's densest rodent population--may soon be showered with poison in an effort to eradicate the mice boom and restore the islands' suffering ecosystem. But the proposal from the U.S. Fish and Wildlife Service has already raised some concern and opposition.
The islands, known as "California's Galapagos," sit 27 miles west of San Francisco and serve as "an ideal breeding and resting location for wildlife, especially seabirds and marine mammals" explains a report. But in recent years, pressure has increased to address the islands' infestation of invasive house mice that were likely introduced by seal-hunting ships in the 19th century.
According to the report, the mice are a potential vector for disease transmission. They also feed on the islands' native invertebrates and seeds, while providing a food resource to migratory owls that prey upon the island's rare birds.
The U.S. Fish and Wildlife Service analyzed 49 ways to tackle the mice infestation and concluded that the only viable alternative to not taking any action is to drop rodenticide pellets from a helicopter. Some critics fear that action will do just as much harm.
"Part of the concern is that rodenticides will get into the water," Kelle Kacmarcik, wildlife solutions manager at animal advocacy group WildCare, told the Marin Independent Journal. The island's surrounding waters are also home to elephant seals and great white sharks.
"I don't want to see the suffering of countless other species, especially when we don't know what the long-term impact will be," former WildCare environmentalist Maggie Sergio told the San Francisco Chronicle.
The proposal details plans to protect the islands' other species by minimizing poison drift into the water, timing the poison drops as to avoid sensitive breeding periods, shooing away birds during the poison drops and removing the mice carcasses.
There will be a public hearing on the proposal on August 29 at Fort Mason.