Restoring Wildlife Habitat on Rat Island: Environmental Assessment
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University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln US Fish & Wildlife Publications US Fish & Wildlife Service 12-2007 Restoring Wildlife Habitat on Rat Island: Environmental Assessment Follow this and additional works at: https://digitalcommons.unl.edu/usfwspubs Part of the Aquaculture and Fisheries Commons "Restoring Wildlife Habitat on Rat Island: Environmental Assessment" (2007). US Fish & Wildlife Publications. 77. https://digitalcommons.unl.edu/usfwspubs/77 This Article is brought to you for free and open access by the US Fish & Wildlife Service at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in US Fish & Wildlife Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Restoring Wildlife Habitat on Rat Island Alaska Maritime National Wildlife Refuge Aleutian Islands Unit Environmental Assessment U.S. Fish and Wildlife Service Alaska Maritime National Wildlife Refuge December 2007 Executive Summary Restoration of natural ecosystem function on Rat Island promises to re-establish native seabirds and other native species, thus returning this wilderness island to a healthy natural community. This restoration cannot occur until the island is cleared of the invasive non-native rats that now dominate the living community. Introduced non-native species are a leading cause of extinctions in island communities worldwide. Increasingly, land managers are removing introduced species to aid in the restoration of native ecosystems. Rats are responsible for 40-60% of all recorded bird and reptile extinctions worldwide. Given their widespread successful colonization on islands and the resulting impact to native species, introduced rats are identified as key species for eradication. Most of the Aleutian Islands lying within the Alaska Maritime National Wildlife Refuge (NWR) provide important breeding habitat for seabirds, including many for which the Aleutians provide a substantial portion of their worldwide range. Norway rats are established on at least 10 Aleutian islands or island groups, and the diversity and numbers of breeding seabirds occurring on those islands are now conspicuously low. Rat-caused modifications to other components of the island ecosystems (e.g., other birds, plants, and invertebrates) are also evident. The restoration of Aleutian ecosystems through introduced predator eradications has long been identified as a priority for Alaska Maritime NWR, and the initial efforts have been directed to removing introduced foxes. The focus now has turned to rats. This Environmental Assessment evaluates the environmental effects of eradicating introduced non-native rats from Rat Island, located in the central Aleutians within Alaska Maritime NWR. The consequences of the No Action alternative are addressed along with the Preferred Alternative (Proposed Action hereafter) which is to eradicate rats from Rat Island employing an aerial broadcast of rodenticide, and subsequently maintaining the island in rodent-free status. The intent of the Proposed Action is to facilitate the restoration of the natural island ecosystem by improving habitat quality for native species. Figure 1. Rat Island is located in the central Aleutian Islands. ii Public Comment Period: December 12, 2007 through January 11, 2008 The Alaska Maritime National Wildlife Refuge is seeking public comment on this Environmental Assessment which proposes the restoration of native species and natural ecosystem function on Rat Island through the eradication of invasive rats. A 30 day comment period opens December 12, 2007. Written comments via fax, mail or email are requested by the close of business January 11, 2008. The document is available online at http://alaskamaritime.fws.gov/news.htm. Reading copies have been placed in the public libraries of the communities of Unalaska, Homer and at the US Fish and Wildlife Service Alaska Regional Office reception desk located at 1011 E. Tudor Road in midtown Anchorage. If you need a paper copy please contact the Refuge. Following the closing of the comment period, the Service will examine the comments and determine whether the Environmental Assessment action warrants a “Finding of No Significant Impact”. If a Finding of No Significant Impact is warranted, plans will proceed for rat eradication on Rat Island. Contact Person: Will Meeks, Deputy Refuge Manager Alaska Maritime National Wildlife Refuge 95 Sterling Highway, Suite 1. Homer, AK 99603 FAX: (907) 235-7783 email: [email protected] iii Table of Contents Executive Summary........................................................................................................................ ii Public Comment Period:................................................................................................................iii Table of Contents........................................................................................................................... iv 1. Purpose & Need .......................................................................................................................... 1 1.1. Introduction.............................................................................................................................. 1 1.2. Purpose of Action .................................................................................................................... 1 1.3. Need for Action........................................................................................................................ 1 1.3.1. Introduced Rats on the Alaska Maritime National Wildlife Refuge............................. 2 1.3.2. Impacts of Introduced Rats on Island Ecosystems in General...................................... 3 1.3.3. Eradication of Rats from Islands................................................................................... 5 1.4. Scope of Analysis .................................................................................................................... 5 1.5. Authority for Action & Regulations Governing Action .......................................................... 6 1.5.1. Authorities for Taking Action....................................................................................... 6 1.5.1.1. U.S. Fish and Wildlife Service statutes, policies, and plans.................................. 6 1.5.1.2. Executive Orders.................................................................................................... 7 1.5.2. Regulatory Framework ................................................................................................. 7 1.5.2.1. Federal laws ........................................................................................................... 8 1.5.2.2 Alaska state laws and policies................................................................................. 8 1.5.2.2.1 Alaska Board of Game..................................................................................... 8 1.5.2.2.2. Alaska Department of Fish and Game (ADF&G) .......................................... 9 1.5.2.2.3. Alaska Department of Health and Social Services, Division of Public Health, Section of Epidemiology............................................................................................... 10 1.5.2.2.4. Alaska pesticide-related laws and responsible entities ................................. 10 1.6. Purpose of This Analysis ....................................................................................................... 11 2. Alternatives............................................................................................................................... 12 2.1. Alternative A: No Action....................................................................................................... 12 2.2. Alternative B (Proposed Action): Introduced Rat Eradication from Rat Island, Aerial Bait Broadcast Technique..................................................................................................................... 12 2.2.1. Summary of Actions ................................................................................................... 12 2.2.2. Description of Action Operations ............................................................................... 13 2.2.2..1 Timing.................................................................................................................. 13 2.2.2.2. Project staging...................................................................................................... 15 2.2.2.3. Introduction to broadcast bait application............................................................ 16 2.2.2.4. Bait pellet composition ........................................................................................ 17 2.2.2.5. Determining application rate................................................................................ 18 2.2.2.6. Number of bait applications................................................................................. 18 2.2.2.7. Bait hopper........................................................................................................... 18 2.2.2.8. Equipment calibration.......................................................................................... 19 2.2.2.9. Flight plan ............................................................................................................ 19 2.2.2.10. Monitoring bait application...............................................................................