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South Farallon Islands Invasive House Mouse Eradication Project; Farallon National Wildlife Refuge, California; Environmental Impact Statement

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Fish and Wildlife Service, Interior.


Notice of availability; request for public comment.


We, the U.S. Fish and Wildlife Service (Service), announce the availability of a draft environmental impact statement (EIS) for a proposed project to eradicate non-native, invasive house mice from the South Farallon Islands, part of the Farallon National Wildlife Refuge off the coast of California. The draft EIS, which we prepared in accordance with the National Environmental Policy Act of 1969 (NEPA), describes the alternatives identified to address the problem of invasive house mice on the South Farallon Islands.


We will accept comments received or postmarked on or before September 30, 2013. Comments submitted electronically using the Federal eRulemaking Portal (see ADDRESSES section, below) must be received by 11:59 p.m. Eastern Time on the closing date.


Document Availability: You may obtain copies of the documents in the following places:

○ San Francisco Bay National Wildlife Refuge Complex Headquarters, 1 Marshlands Road, Fremont, CA 94555.

○ The following library:

San Francisco Public Library, 100 Larkin Street, San Francisco, CA 94102.

Submitting Comments: You may submit written comments by one of the following methods:

  • Electronically: Go to the Federal eRulemaking Portal: In the Search box, enter FWS-R8-NWRS-2013-0036, which is the docket number for this notice. Then, on the left side of the screen, under the Document Type heading, click on the Notices link to locate this document and submit a comment.
  • By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS-R8-NWRS-2013-0036; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.

We request that you send comments only by the methods described above. We will post all information received on This generally means that we will post any personal information you provide us (see the Public Comments section below for more information).

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Gerry McChesney, Refuge Manager, 510-792-0222, ext. 222 (phone).

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In 2009, the Service completed a Comprehensive Conservation Plan (CCP) and Environmental Assessment/Finding of No Significant Impact to guide the management of the Farallon National Wildlife Refuge (Refuge) over a 15-year period (75 FR 5102, February 1, 2010). The wildlife management goal of the selected management alternative in the CCP is to protect, inventory, and monitor, as well as to restore to historic levels, breeding populations of 12 seabird species, 5 marine mammal species, and other native wildlife. One of the strategies identified to meet this goal is the eradication of the non-native, invasive house mouse (Mus musculus) from the South Farallon Islands, and the prevention of future human introduction of mice.

We now propose to eradicate invasive house mice from the South Farallon Islands. The purpose of this project is to benefit native seabirds, amphibians, invertebrates, and plants, as well as to enhance ecosystem processes on the islands. The South Farallon Islands have sustained ecological damage over many decades from the presence of invasive mice. Eradicating house mice would eliminate the last remaining invasive vertebrate species on the Refuge, thereby enhancing the recovery of sensitive seabird populations on the islands.

In 1909, President Theodore Roosevelt established the Farallon National Wildlife Refuge (Refuge) as a preserve and breeding ground for marine birds under Executive Order 1043. The Refuge originally encompassed only the North and Middle Farallon Islands and Noonday Rock. In 1969 the Refuge was expanded to include the South Farallon Islands, and is still managed with the same basic purpose today. Several areas are designated wilderness as regulated by the Wilderness Act of 1964 (PL 88-577). Wilderness areas include all islands and islets in the Refuge except for Southeast Farallon Island. The isolated nature, varied and extensive habitats, and adjacent productive marine environment make the Farallon Islands an ideal breeding and resting location for wildlife, especially seabirds and marine mammals. The Refuge comprises the largest continental U.S. seabird breeding colony south of Alaska, and supports the world's largest breeding colonies of ashy storm-petrel (Oceanodroma homochroa), Brandt's cormorant (Phalacrocorax penicillatus), and western gull (Larus occidentalis). Prior to the introduction of non-native mammals, the wildlife of the Farallon Islands were nearly devoid of land-based predatory threats. Introduced European rabbits and cats, which were later removed, and mice, which remain on the South Farallon Islands today, have had noticeable negative impacts on native species.

Invasive house mice directly and indirectly cause negative impacts to the populations of small, crevice-nesting seabirds on the South Farallones, particularly storm-petrels. In order to reduce this impact, the Service has identified mouse eradication as a critical step in fulfilling its main purpose to protect and restore the native ecosystem of the South Farallon Islands. Eradicating mice would increase the survivorship and local population sizes of at least two seabird species, the ashy storm-petrel and Leach's storm-petrel (Oceanodroma leucorhoa). The eradication project would also benefit native amphibians, invertebrates, and plants, including the endemic Farallon arboreal salamander (Aneides lugubris farallonensis) and endemic Farallon camel cricket (Farallonophilus cavernicolus).


In 2011, we published a notice of intent (NOI) to prepare an EIS (76 FR 20706, April 13, 2011). We then developed a range of alternatives to focus on the primary issues identified by resource specialists within the Service, national and international experts in island rodent eradication, public comments received after the NOI to prepare the EIS was released, and government regulatory agencies that have a stake in the decision-making process. To decide which action alternatives to fully analyze in the Draft EIS, we used a structured decision-making approach, by which we assessed and compared a total of 49 potential mouse-removal methods. The Start Printed Page 50083development of alternatives was also informed by Service policies regarding the use of pesticides and the minimum requirements analysis process under the Wilderness Act. Three alternatives are analyzed in the draft EIS:

Alternative 1: No-Action Alternative

Under this alternative, we would not take any action to eradicate mice from the South Farallon Islands, maintaining the status quo. Native species would continue to be impacted by invasive mice. However, other ongoing invasive species management programs on the South Farallones would continue based on previous agency decisions. Low-intensity mouse control, primarily snap-trapping, currently occurs within and around the residences and other buildings on Southeast Farallon Island. These localized control efforts would continue under the no-action alternative, but the mouse population on the rest of the South Farallones would not be subject to control efforts.

Under this alternative, we would also continue management activities focused on protecting storm-petrels and their habitat on the islands, including invasive plant control and nest habitat construction. The current biosecurity measures would likely continue under this alternative, which could leave the Farallones at risk of additional invasions by non-native animal species.

Alternative 2: Eradicate invasive house mice from the South Farallon Islands by aerial broadcast of Brodifacoum 25D-Conservation as the primary method of bait delivery

Under this alternative, the project area would be treated with the rodenticide Brodifacoum 25D Conservation. The primary delivery of the bait would be through two aerial applications, with hand baiting and bait stations as a secondary means of bait delivery in selected areas. Bait applications would be separated by 10 to 21 days. The applications would take place between October and December. A comprehensive gull hazing program would be implemented as part of the action to minimize the exposure of gulls to bait. Mitigation measures in this alternative include minimizing activities in wilderness areas, protecting cultural resources, minimizing wildlife disturbances, minimizing bait drift into the marine environment, raptor capture and hold/relocation, use of bait stations in certain areas with high numbers of roosting gulls, and the removal of carcasses of mice and non-target species, and covering the water catchment pad.

Monitoring of operational, mitigation, and ecosystem restoration objectives would be conducted before, during, and after the proposed mouse eradication. In addition, in order to mitigate the risk of future rodent reinvasion, a biosecurity plan would be implemented prior to the proposed eradication to prevent and detect future rodent incursions.

Alternative 3: Eradicate invasive house mice from the South Farallon Islands by aerial broadcast of Diphacinone D50-Conservation as the primary method of bait delivery

Under this alternative, the project area would be treated with the rodenticide Diphacinone D50-Conservation. Alternative 3 differs from Alternative 2 in the type of rodenticide used for the proposed eradication and the number of applications that may be necessary. A comprehensive gull hazing program would be implemented to minimize the exposure of gulls to bait. Alternative 3 would include the same mitigation measures described under Alternative 2, as well as the monitoring program and the biosecurity plan. Under Alternative 3, Diphacinone D50-Conservation would be broadcast primarily by helicopter, with some hand baiting and bait stations used in selected areas. However, under Alternative 3 we would need to broadcast a portion of the total amount of bait required during up to three or four applications, each separated by approximately 7 days. The number of applications will be determined partly by mouse uptake of bait and degradation of bait by rainfall. The bait application would take place between October and December.

NEPA Compliance

We are conducting environmental review in accordance with the requirements of NEPA, as amended (42 U.S.C. 4321 et seq.), its implementing regulations (40 CFR parts 1500-1508), other applicable regulations, and our procedures for compliance with those regulations. The draft EIS discusses the direct, indirect, and cumulative impacts of the alternatives on biological resources, cultural resources, wilderness, water quality, and other environmental resources. Measures to minimize adverse environmental effects are identified and discussed in the draft EIS.

Public Comments

We request that you send comments only by one of the methods described in ADDRESSES. If you submit a comment via, your entire comment—including any personal identifying information—will be posted on the Web site. We will post all hardcopy comments on as well. If you submit a hardcopy comment that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. Comments and materials we receive, as well as documents associated with the notice, will be available for public inspection on at Docket No. FWS-R8-NWRS-2013-0036.

We will hold one public meeting to solicit comments on the draft EIS. We will mail a separate announcement to the public with the exact date, time, and location of the public meeting. We will also post the time, date, and location of the public meeting on our refuge Web site at:​refuge/​farallon. We will accept both oral and written comments at the public meeting.

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Alexandra Pitts,

Acting Regional Director, Pacific Southwest Region.

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[FR Doc. 2013-19939 Filed 8-15-13; 8:45 am]