Conserving the Nature of America

News Release

Lehua Island Ecosystem Restoration Plan Available for Public Review

July 8, 2008


Division of Public Affairs
External Affairs
Telephone: 703-358-2220

Public Meeting to be Held on Kauai

The U.S. Fish and Wildlife Service and the Hawai?i Department of Land and Natural Resources Division of Forestry and Wildlife are seeking public comments on the Draft Supplemental Environmental Assessment for the Lehua Ecosystem Restoration Project.

The document available for public review is a supplement to the original Final Environmental Assessment approved in September 2005. That document determined a finding of no significant impact for proposed actions to protect and promote native Hawaiian species on Lehua. In addition to the comment period, a public meeting will be held on Kauai at the Waimea Neighborhood Center, 4556 Makeke Road, Waimea, HI 96796 on Thursday, July 24th from 7 to 9 p.m.

The U.S. Fish and Wildlife Service and the Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, working with USDA - APHIS - Wildlife Services, propose to eradicate introduced rats from Lehua via aerial application of the rodenticide diphacinone.

Bait pellets containing 50 parts per million of diphacinone (99.995% inert grain-based material) will be evenly deposited on Lehua using a bait hopper carried under a helicopter. The helicopter pilot will control the application and use a global positioning system (GPS) to track distribution of the bait and ensure even coverage.

Diphacinone was prescribed for many years (marketed as Dipaxin) as a blood thinner (anti-coagulant) for heart patients, but use of this drug was discontinued because more effective anti-coagulants were found (including Heparin and Coumadin).

Since the early 1990s, 57 islands worldwide have been cleared of rats using a similar method of aerial bait distribution. This method was used in February 2008 to control rats on Mokapu islet off the north shore of Molokai, and monitoring is being conducted to insure that all the rats are gone.

The proposed project will protect and restore native seabirds, plants and other wildlife on Lehua by eradicating rats, a nonnative species damaging the islands ecosystem. Once the rats are removed, a plant restoration project will follow. The Service and State anticipate that the proposed project would have no significant negative environmental impact, but rather provide a net benefit to native species and their habitats on Lehua.

Since the original environmental assessment was approved, several important modifications to the rat eradication operation have been determined to be more effective while also minimizing and/or avoiding adverse impacts to nontarget species such as birds.

Therefore, the USFWS and DLNR, as joint lead agencies, have determined that the original 2005 EA should be supplemented to evaluate the impacts associated with these modifications. The purpose of this supplement is to describe the rat eradication operation for Lehua in detail as modified and evaluate the effectiveness and impacts associated with the entire operation, including the modifications.

The primary changes to the original environmental assessment are:

  • The operation will be conducted only during the winter months (December through February) when rat populations and the presence of dependent juvenile rats are lowest and native nontarget migratory species are present in the lowest numbers. In addition, Lehua is rarely used during this time by fisherman, tourists, and opihi pickers.
  • If the application of rodenticide pellets happens after albatross chicks hatch, then all pellets within 6 feet of each nest will be manually removed so chicks cannot play with or accidentally eat the pellets.
  • Aerial application is more effective for distributing the pellets over very rough and unsafe terrain, this also results in fewer disturbances to birds and monk seals and is safer on Lehua for all involved, and therefore no bait stations, hand broadcast or burrow baiting will be used.

The National Marine Fisheries Service has concluded that the modifications to the operation will not harm Hawaiian monk seal and sea turtles.

Lehua is uninhabited and located less than a mile north of Niihau and approximately 20 miles west of Kauai. The 290-acre State Seabird Sanctuary provides habitat for at least 16 species of seabirds, as well as monk seals, native coastal plants and insects. The U.S. Coast Guard administers the island, and also maintains a navigational light on the island.

Rats are known to have eliminated many seabird species from islands around the world. They also feed on native plants and insects, suppressing or eliminating populations of these species as well.

On many islands, rabbits have also decimated the vegetation and competed with seabirds for use of ground burrows. Rabbits were successfully eradicated from Lehua through intensive hunting efforts in 2005 and 2006.

Diphacinone has been shown to be an effective toxicant for rats in Hawaii and throughout the world. Diphacinone is preferred because it is less toxic to nontarget species (such as birds) than other rodenticides used for rodent eradication projects on islands.

Seawater, invertebrates and fish will be sampled after the rodenticide application to test for rodenticide residues. Test results will be published in the newspaper. The agencies recently conducted a similar operation on Mokapu Island, located off the north coast of Molokai, in which sampling of seawater, opihi and fish detected no diphacinone residues.

The Draft Environmental Assessment was prepared jointly by the Service and DLNR in accordance with the National Environmental Policy Act of 1969, as amended, and Chapter 343, Hawaii Revised Statues.

Copies of the Draft EA may be obtained via the Services website at, or by contacting the Pacific Islands Fish and Wildlife Office at 808 792 9400. A public notice of the comment period will also be published on July 8, 2008, in the State of Hawaii Office of Environmental Quality Control bulletin, The Environmental Notice.

The Service and DLNR are requesting written comments regarding the proposed action from interested individuals, organizations, and agencies. The public comment period is from July 8, 2008, to August 7, 2008. Written comments should be addressed to Chris Swenson, U.S. Fish and Wildlife Service, 300 Ala Moana Boulevard, Room 3-122, Honolulu, Hawaii 96850, or faxed to 808 792 9580. All written comments must be postmarked by August 7, 2008.

Information contained in older news items may be outdated. These materials are made available as historical archival information only. Individual contacts have been replaced with general External Affairs office information. No other updates have been made to the information and we do not guarantee current accuracy or completeness.

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