E8-13786. Incidental Takes of Marine Mammals During Specified Activities; Rat Population Eradication at Rat Island, AK

AGENCY:

National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.

ACTION:

Notice; proposed incidental take authorization; request for comments.

SUMMARY:

NMFS has received an application from the U.S. Fish and Wildlife Service (USFWS) for an Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by harassment, incidental to the eradication of rat populations at Rat Island, AK. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposed IHA for these activities.

DATES:

Comments and information must be received no later than July 18, 2008.

ADDRESSES:

Comments on the application should be addressed to Michael Payne, Chief, Permits, Conservation and Education Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225. The mailbox address for providing email comments is PR1. [e-mail]. Comments sent via e-mail, including all attachments, must not exceed a 10-megabyte file size.

A copy of the application containing a list of the references used in this document may be obtained by writing to the address specified above, telephoning the contact listed below (see FOR FURTHER INFORMATION CONTACT), or visiting the internet at: http://www.nmfs.noaa.gov/​pr/​permits/​incidental.htm.

Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT:

Howard Goldstein or Ken Hollingshead, NMFS, [phone].

SUPPLEMENTARY INFORMATION:

Background

Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

Authorization shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for certain subsistence uses, and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as ”...an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.”

Section 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the United States can apply for an authorization to incidentally take small numbers of marine mammals by harassment. Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as:

any act of pursuit, torment, or annoyance which (I) has the potential to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering [Level B harassment].

Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of an application followed by a 30-day public notice and comment period on any proposed authorizations for the incidental harassment of marine mammals. Within 45 days of the close of the comment period, NMFS must either issue or deny issuance of the authorization.

Summary of Request

On February 29, 2008, NMFS received a letter from the USFWS, requesting issuance of a proposed IHA. The requested IHA would authorize the take, by harassment, of small numbers of Steller sea lions (Eumetopias jubatus), and Pacific harbor seals (Phoca vitulina richardsi), incidental to rat population eradication and bait application operations. Operations will be conducted on foot, by watercraft (boat), and by aircraft (helicopter) by a field crew.

Additional information on the eradication operations is contained in the application and Environmental Assessment (EA), which is available upon request (see ADDRESSES).

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 Norway 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 (AMNWR) 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 AMNWR, and the initial efforts have been directed to removing introduced Arctic foxes. The focus now has turned to rats. The intent of the proposed operations is to facilitate the restoration of the natural island ecosystem by improving habitat quality for native species.

Proposed Rat Eradication Project Description

Rats were first introduced to Alaska over 200 years ago at Rat Island in the western Aleutian Island archipelago. Prior to this introduction, the island likely supported significant populations of breeding seabirds and other ground nesting birds which evolved in the absence of mammalian predators. Since their introduction, rats and foxes have extirpated breeding seabirds and had detrimental impacts on vegetation and intertidal life on the island. AMNWR personnel eradicated foxes on Rat Island in 1984. Working with others, the USFWS proposes to eradicate rats from the island using removal techniques based on successful island rat eradications elsewhere in the U.S. and globally.

The purpose of eradicating rats from Rat Island is to conserve, protect and enhance habitat for native wildlife species, especially nesting habitat for seabirds, and to restore the biotic integrity of the island. The overarching goal in a successful eradication is to ensure the delivery of a lethal dose of toxicant to every rodent on the island. The primary method for eradicating rats from Rat Island is delivery of compressed-grain bait pellets containing rodenticide to every rat territory on the island through aerial broadcast. The bait pellets will contain 25 ppm brodifacoum and will be applied according to Environmental Protection Agency (EPA) approved label directions.

The need for caution near the marine and freshwater environments, due to the chemical composition of the bait pellets and potential for contamination of the water column (bait pellets disintegrate and dissolve quickly in water), requires a buffer when broadcasting the rodenticide. As a result, some areas may not receive the optimal bait coverage with helicopter broadcast. In cases where it is evident or suspected that any land area on Rat Island or offshore islets did not receive full coverage, there will be supplemental systematic hand broadcast either by foot, boat, helicopter, or any combination of the above. All bait application activities will be conducted by, or under the supervision of, a Pesticide Applicator certified by the State of Alaska.

Proposed Staging and Preparation

Field crews will visit Rat Island in the summer prior to the rat eradication to install temporary infrastructure and storage sites. These will include: 1) a camp site capable of supporting 20 people for up to seven weeks; 2) three bait staging areas, where bait will be contained in up to 200 storage units at each staging area; and 3) a fuel storage site that will comply with all appropriate safety standards and regulations.

Additional material may be brought to the island at that time and staged for the fall application of bait. Helicopters will deliver most of the necessary materials to each site on the island from a vessel anchored nearby. Staging procedures in summer will be conducted using a helicopter capable of lifting a 700 kg (1,543 lbs) payload. Helicopter operations during project staging will be localized to discrete flight paths and landing sites servicing the camp, three bait staging locations, and a fuel storage site.

It is possible that some of the material needed for eradication will not be available in the summer. In this case, that material will be staged on the island during the week prior to the fall application of bait.

Proposed Bait Application

Proposed bait application operations will be conducted using two single-primary-rotor/single tail-rotor helicopters. Bait will be applied from specialized bait hoppers slung 15-20 m (49-66 ft) beneath the helicopter. Helicopter operations for the bait application will necessitate low-altitude overflights of the entire land area of Rat Island and adjacent vegetated islets. The helicopter will fly at a speed ranging from 25-50 knots (46-93 km/hr or 29-58 mph) at an average altitude of approximately 50 m (164 ft) above the ground.

To make bait available to all possible rat home ranges on the island, bait will need to be applied evenly across emergent land area, with every reasonable effort made to prevent bait spread into the marine environment. The baiting regime will follow common practice in which parallel, overlapping flight swaths are flown across the interior island area and overlapping swaths with a deflector attached to the hopper (to prevent bait spread into the marine environment) flown around the coastal perimeter. Flight swaths will be defined by the uniform distance of bait broadcast from the hopper, ranging from 50-75 m (164-246 ft). Flight swaths will be flown in a parallel pattern, with subsequent flight swaths overlapping the previous by approximately 25-50% to ensure no gaps in bait coverage.

Proposed Special Treatment of the Islet off Ayugadak Point

The islet located 1.6 km (1 mi) off Ayugadak Point is a Steller sea lion rookery, designated as Critical Habitat under the Endangered Species Act (ESA). The islet is also potential rat habitat and the thick kelp beds between the main island and this islet make rat migration to and from the islet possible. Bait will be delivered to the islet off Ayugadak Point with an adaptive alternative-baiting strategy designed to minimize disturbance of Steller sea lions from helicopters.

During the month of August, project crews will attempt to access the islet by boat, landing on a beach that is out of view of the Steller sea lion rookery. Personnel will install multiple enclosed bait stations on the islet, which will be designed to provide easy access to the bait inside for rats while minimizing bait access by non-target species that may be present on the islet, including song sparrows. Stations will be anchored securely in place, and filled with enough bait to ensure that any rats on the island will have bait available for many weeks.

During the major bait application operation in the fall, project crews will attempt to access the islet by boat again, although the sea state during this season may make access more difficult than earlier in the season. If personnel can access the island by boat, they will check the bait stations installed earlier for signs of bait consumption or other rat activity. Bait stations will be refilled as necessary during this visit. If rats are detected or suspected, personnel may additionally hand-broadcast bait pellets on the islet according to label instructions.

If project field crews are unable to access the islet by boat at any time during fall operations it will be necessary to aerially treat the island.

Proposed Demobilization

Once eradication has been completed operational demobilization and clean-up will commence. A charter vessel will be employed to transport all crew and equipment off the island. Demobilization and clean-up will include deconstructing and removing: 1) field camp; 2) garbage and human waste; 3) staging areas; and 4) fuel. All tents, weatherports, and other field camp equipment will be disassembled, packed, and returned to the vessel by helicopter. All equipment will be removed from bait staging areas and transported off the island. The wooden storage boxes will be disassembled, bound, and transported by helicopter back to the vessel. Excess fuel will also be transported back to the vessel by helicopter.

Additional details regarding the proposed rat eradication operations can be found in the Environmental Assessment (EA): “Restoring Wildlife Habitat on Rat Island” USFWS 2007 (EA). The EA can also be found online at: http://alaskamaritime.fws.gov/​news.htm

Proposed Dates, Duration, and Region of Activities

Rat Island is located in the western Aleutian Islands approximately 51° 80′ North, 178° 30′ West, approximately 1,931 km (1200 mi) west of Anchorage, Alaska. The Ayugadak Point rookery is located on an islet approximately one mile southeast of Rat Island at 51° 45.5′ North, 178deg; 24.5′ East.

Proposed Staging and Preparation at Rat Island

The summer staging and preparation activities for Rat Island are expected to take 5 days during the week of July 7-11. Helicopter support during this period is estimated to take two days. Wooden storage boxes and platform construction materials will be staged at three areas, as indicated in Figure 1 in USFWS' IHA application. Fuel and all other camp materials will be delivered to the Gunner's Cove field camp location.

All materials not available during the summer staging and preparation periods will be transported to Rat Island during the week of September 22-27, 2008. Helicopter support during this period is estimated to take two days.

Proposed Bait Application at Rat Island

Bait application will commence once staging and preparation have been accomplished as planned. The application will occur during a 45-day time period from September 28-November 11, 2008 (except on the islet off Ayugadak Point). The bait application is estimated to take approximately 35 hours total flight time; however, the implementation will likely be interrupted by typical fall weather patterns in the central Aleutians, which are notoriously unsettled. Therefore, a maximum of 45 days will be allotted to achieve the 35 hour operation window.

Proposed Demobilization at Rat Island

During the first week of August, a project crew will attempt to access the islet by boat to install bait stations containing rodenticide. The installation will take approximately four hours.

If weather and sea conditions allow the installation of bait stations in August, a project crew will attempt to access the islet by boat again during the major bait application operations in October. Sea state during this season may make access more difficult than the August attempt. If personnel can access the island by boat, they will check the bait stations installed earlier for signs of bait consumption or other rat activity and refill stations as necessary. Personnel may also hand-broadcast bait pellets on the islet if rats are detected or suspected. This work is estimated to take between four and six hours.

If project crews are not able to access the islet in August or during the Rat Island bait application in October, it will be treated by aerial broadcast. This would take place during the October 1-November 11, 2008 time frame and require approximately 15 minutes of helicopter flight time.

Proposed Bait Application at Ayugadak Point Rookery

During the first week of August, a project crew will attempt to access the islet by boat to install bait stations containing rodenticide. The installation will take approximately four hours.

If weather and sea conditions allow the installation of bait stations in August, a project crew will attempt to access the islet by boat again during the major bait application operations in October. Sea state during this season may make access more difficult than the August attempt. If personnel can access the island by boat, they will check the bait stations installed earlier for signs of bait consumption or other rat activity and refill stations as necessary. Personnel may also hand-broadcast bait pellets on the islet if rats are detected or suspected. This work is estimated to take between four and six hours.

If project crews are not able to access the islet in August or during Rat Island bait application in October, it will be treated by aerial broadcast. This would take place during the October1-November 11 time frame and require approximately 15 minutes of helicopter flight time.

Status and Distribution of Affected Species

Table 1. Recent survey results for pinnipeds in the Rat Island area.

Species	Number	Year	Source	Comments
Harbor Seal	93 “Fairly common”	1999 2007	Small et al. in press Buckelew et al. 2007	Aerial survey Often seen in water, not seen hauled out
Steller sea lion	45 254	2004 2005	NMFS database NMFS database	Aerial survey for Rat Is.(adults and juveniles) Aerial survey for Ayugadak Point Rookery (includes 83 pups)
	present	2007	Bucklew 2007	Seen from boat offshore at Rat Is. And Ayugadak Pt.

Steller Sea Lion

Steller sea lions range along the North Pacific Rim from northern Japan to California. They are most abundant in the Gulf of Alaska and Aleutian Islands (NMFS, 2006). Two separate stocks of Steller sea lions are recognized in U.S. waters; an eastern U.S. stock that includes animals east of Cape Suckling, Alaska (144° West), and a western U.S. stock which includes animals west of Cape Suckling. The western Distinct Population Segment (DPS) of Steller sea lions has experienced a major decline of 75% over the past 20 years (Calkins et al., 1999; USFWS, 1997; NMFS, 2007). Consequently the western DPS of Steller sea lions were listed as Endangered under the ESA in 1997. The reasons for this decline are not entirely known and are currently under investigation.

Aerial survey data from 2004-2005 were used to calculate a minimum population estimate of 39,988 animals for the western U.S. waters stock. The Bering Sea/Aleutian Islands area population estimate for the same period is 20,578 (NMFS, 2006).

Steller sea lions are considered non-migratory with dispersal generally limited to juveniles and adult males. In the Aleutian Islands, Steller sea lions generally breed and give birth from late May to early July (Pitcher and Calkins, 1981), and pups remain at rookeries until about early to mid-September (Calkins et al., 1999). Non-reproductive animals congregate at haul out sites.

At Rat Island, a persistent haul-out side is known at the west end of the island near Krysi Point and a rookery is known from the islet off Ayugadak Point. Both sites were active in 2007 (Buckelew et al., 2007).

Pacific Harbor Seal

In the Pacific Ocean, harbor seals occur in coastal waters and estuaries from Baja California north along the west coast of the U.S. and Canada to Alaska including the Aleutian Islands, southern Bristol Bay and the Pribilof Islands. Harbor seals living in the Aleutian Islands are part of the Gulf of Alaska stock. The Gulf of Alaska stock has experienced significant declines ranging from 50-85% over the past 30 years (NMFS, 2006). Limited information suggests some modest recovery from initial declines and the stock has not been listed under the ESA. The current statewide population estimate for Alaska harbor seals is 180,017 (NMFS, 2006).

Harbor seals are generally non-migratory with some local movements related to season, weather, and food availability (NMFS, 2006). In Alaska, harbor seals typically give birth to a single pup between May and mid-July. Pups are generally weaned within one month and separate from their mother. Harbor seals in the Gulf of Alaska undergo an annual molt which peaks between the first week in August and the first week in September (Daniel et al., 2003). Harbor seals are found in scattered locations along the shores of Rat Island and some offshore islets.

Incidental Taking Authorization Requested

The proposed rat eradication effort and associated operations may result in the taking of marine mammals by Level B incidental harassment only. As a result, the USFWS has requested an IHA for Level B harassment. An incidental take of Level B harassment occurs if an animal moves away any distance in response to the presence of field crew personnel, watercraft, and/or aircraft, or if the animal was already moving and changed direction. Animals that raise their head and look at field crew personnel and/or operated vehicle without moving are not considered disturbed. Most incidental takings would be related to harassment from the noise and visual presence/ movement of helicopter operations during the bait application period. A small number of takes could also occur as a result of human presence and boat operations during the course of the project.

The use of a rodenticide is not expected to result in any Level A harassment (i.e., injury) or death of marine mammals. Marine mammals are unlikely to ingest bait pellets of rodenticide opportunistically or accidentally. The rodenticide is retained at low levels in body tissues and numerous large exposures would have to occur in order to ingest an injurious or lethal amount. Steller sea lions and harbor seals diet does not include either bait pellets or rat carcasses that have succumbed to the rodenticide application.

Further information on the biology and distribution of these species and others in the region can be found in USFWS' application and EA, which is available upon request (see ADDRESSES), and the Marine Mammal Stock Assessment Reports, which are available online at http://www.nmfs.noaa.gov/​prot_​res/​PR2/​Stock_​Assessment_​Program/​individual_​sars.html.

Potential Impact and Effects of the Proposed Activity on the Marine Mammals

Steller Sea Lions

The response of pinnipeds, like Steller sea lions, to aircraft overflights varies from no discernable reaction to completely vacating haul outs after a single overflight (Calkins, 1979; Efroymson and Suter, 2001). Approaching aircraft generally flush animals into the water. In one case, Withrow et al. (1985 in Richardson et al., 1995) reported Steller sea lions left a beach in response to a Bell 205 helicopter >1.6 km away, but the noise from a helicopter is typically directed down in a “cone” underneath (Richardson et al., 1995) so disturbance at such great distance is probably uncommon.

At Rat Island, known persistent haul out sites will be avoided during proposed staging operations as will any other haul out sites discovered prior to helicopter operations. In spite of these precautions, sea lions encountered unexpectedly during proposed helicopter operations could be flushed from land temporarily. An individual sea lion's exposure to peak noise from the helicopter will be limited to animals that remain ashore, and is likely to be of short duration, as the elevation and speed of the helicopter will limit the time that any single location is exposed to maximum noise.

It will be more difficult to avoid known haul sites on Rat Island with the helicopter during bait application because of the need for thorough coverage. No pups are expected on Rat Island. The impacts of disturbance to sea lions during molting (a sensitive period to disturbance, Richardson et al., 1995) will be minimized by timing overflights after the peak molting period is over.

Proposed installation of bait stations on the islet off Ayugadak Point in August is likely to result in short-term displacement of some non-breeding animals from the islet. This disturbance is likely to be limited to the few-hour period when personnel are present on the island. Sea lion pups will likely be present on the islet during installation of bait stations. To prevent disturbance to the rookery, the islet will be approached slowly in a small boat, from the side of the island opposite and out of sight of the rookery. While on the islet, personnel will remain out of sight of the rookery.

In October, the bait stations on the islet will need to be replenished. Again, the approach to the island will be slow, and opposite the rookery. This may result in displacing a few non-breeding animals for a few hours when personnel are present on the islet. If it is not possible to land a skiff on the islet, the island will be baited with the helicopter as described in the EA, in the fall after the pupping and primary molting season. This is likely to result in flushing sea lions from the islet resulting in short-term displacement. However, as helicopter baiting will be a very short process (approximately 15 minutes), disturbance to Steller sea lions is likely to be very short-term.

Risks to Steller's sea lions from personnel camps on Rat Island will be minimal as camps and storage sites will be located well inland away from possible Steller sea lion haul out areas.

Overall, the effects of the operations described in the EA on Steller's sea lions will vary depending on the number of disturbance events. However, the short-term displacement from haul-outs that is likely to occur as a result of helicopter noise and personnel is not anticipated to have any effect on overall energy balance or fitness of any individual animals.

It is not likely that any Steller sea lions will suffer injury or the potential for injury as a result of the activities described in the EA. The potential disturbance associated with the project would result in Steller sea lions entering the water; which they do as part of their normal pattern of behavior, and possibly flushing of groups of animals at pinniped haul-outs. This analysis concludes that implementation of rat eradication activities as described in the EA is not likely to adversely affect individual Steller sea lions on an individual or population level.

Pacific Harbor Seals

The response of pinnipeds to proposed aircraft overflights varies from no discernable reaction to completely vacating haul outs after a single overflight (Calkins, 1979; Efroymson and Suter, 2001). Approaching aircraft generally flush animals into the water.

During proposed staging operations, project managers will plan helicopter flight lines and boat travel to minimize the potential for disturbance to harbor seal haul-outs known from existing databases and surveys conducted prior to operations. However, in spite of these precautions, seals encountered unexpectedly during helicopter operations could be flushed from land temporarily. An individual seal's exposure to peak noise from the helicopter will be limited to animals that remain ashore, and is likely to be of short duration, as the elevation and speed of the helicopter (see Description of Activities, above) will limit the time that any single location is exposed to maximum noise.

It will be more difficult to avoid known haul-out sites of Rat Island with the helicopter during proposed bait application because of the need for through coverage of the entire island. No young pups are expected on Rat Island during the fall. The impacts of disturbance to seals during molting (another sensitive period) will be minimized by timing overflights after the peak molting period is over.

The sporadic personnel presence and temporary infrastructure installations that may be necessary near seal haul-outs during both proposed staging and bait application operations may result in localized disturbances, although this is much less likely to disturb animals than helicopter overflights. The camps and staging areas themselves will be well inland and will have negligible impacts on seals hauled out on the coastline.

Overall, the short-term displacement from haul-out sites that is likely to occur as a result of helicopter noise and personnel activities is not anticipated to have any significant effect on overall energy balance or fitness of any individual animals.

It is not likely that any harbor seals will suffer injury or the potential for injury as a result of project activities. Therefore, this analysis concludes that implementation of rat eradication activities is not likely to result in significant effects to harbor seals at an individual or population level.

Variable numbers of sea lions and harbor seals typically haul out near bait application sites used for proposed eradication operations, with breeding activity occurring at one known site. Pinnipeds likely to be affected by rat eradication activity are those that are hauled out on land at or near bait application sites.

Incidental harassment may result if hauled animals move away from the field crew personnel, watercraft, and aircraft. For the purpose of estimating the potential numbers of pinnipeds taken by these proposed activities, NMFS assumes that pinnipeds that move or change the direction of their movement in response to the presence of field crew personnel are taken by Level B Harassment. Although marine mammals will not be deliberately approached by field crew personnel during proposed operations, approach may be unavoidable if pinnipeds are hauled out directly upon the bait application sites. If disturbed, hauled-out animals may move toward the water without risk of encountering significant hazards. In these circumstances, the risk of injury or death to hauled animals is very low.

The risk of marine mammal injury or mortality associated with rat eradication operations increases somewhat if disturbances occur during breeding season, as it is possible that mothers and dependent pups could become separated. If separated pairs don't reunite fairly quickly, risks of mortality to pups (through starvation) may increase. Also, adult Steller sea lions may trample sea lion pups if disturbed, which could potentially result in the injury or death of pups. However, to mitigate this risk, NMFS and USFWS proposes to include time of year restrictions to limit the presence of field crew personnel activities to months that Steller sea lion and harbor seal dependent pups are not present at the bait application sites. Last, field crew personnel are to use great care approaching sites with pinnipeds and will leave as soon as possible to minimize effects. Because of the circumstances and the proposed IHA requirements discussed above, NMFS believes it highly unlikely that the proposed activities would result in the injury or mortality of pinnipeds.

For the purposes of estimating take in the IHA, NMFS estimates take as the total of all three categories of disturbed behavior recorded (discussed in the Proposed Monitoring and Reporting section below).

Number of Marine Mammals That May Be Affected

Rat Island

Most of the disturbance associated with the Rat Island eradication will be a result of aircraft noise. The helicopters used to apply bait to the island will make two passes across most of the island to ensure success of the project. This could result in two harassment incidents of Steller sea lions and harbor seals that are hauled out at that time. The area surrounding a known Steller sea lion haul out at Krysi Point will be avoided by all activities other than bait application. Harbor seals use many parts of Rat Island shoreline and could also be affected by boat operations and personnel movements. Thus the number of takes was estimated at 2.5 for each individual of this species.

Steller sea lions at Rat Island were counted during an aerial survey in 2004. The number of animals during that survey was increased to allow for potential population growth and then used to calculate the total take in Table 2 (below).

The composition of Steller sea lions, which haul out away from rookeries, shifts between seasons and is not well understood. Although no pups are expected at Rat Island, determining the age and sex ratio of animals using the known haul out near Krysi Point in October is difficult at best. For this reason the number is calculated as adult and sub-adult animals without reference to the sex of these animals.

Harbor seals at Rat Island were counted by an aerial survey in 1999. The number of animals recorded during that survey was increased to allow for potential population growth and then used to calculate the total take in Table 2 (below). Information regarding the demographics of harbor seals on Rat Island is not available. The number of animals recorded in the 1999 survey was used to calculate a total number of harbor seal takes.

Table 2. Estimated number of marine mammals affected by aircraft operations on Rat Island.

M= male, F= female

Species	# of Animals	# of take events per animal	Pups	Pups	Subadults M F	Subadults M F	Adults M F	Adults M F	Total # of Takes
Steller sea lion	65	2	0	0	?	?	?	?	130
Pacific harbor seal	100	2.5	?	?	?	?	?	?	250

Ayugadak Point Rookery

Project crews will attempt to access the Ayugadak Point islet by boat in early August. Landing will be attempted on a beach that is out of view of the rookery. The topography of the islet will allow bait stations to be installed without detection by animals on the rookery. The installation of bait stations will be conducted in a manner that will not disturb animals (adults and pups) on the rookery itself. Previous surveys at the islet have sometimes encountered one or two non-breeding bulls outside of the rookery area near the landing area. These were young or old bulls unable to hold a territory at the rookery. If weather allows a visit in August, a follow-up visit will be attempted in October and could result in a similar take event. A female with a dependent pup has not been encountered outside the rookery area on the islet. However, marine mammals can be unpredictable and this remote possibility cannot be completely discounted. A survey of Steller sea lions was conducted by NMFS in 2005. This survey data was increased to allow for potential population growth and then used to calculate the number of animals anticipated to be affected by this proposed operation plan in the table below. The numbers in the table below also reflect the remote possibility of encountering a female with a dependent pup outside the rookery area.

There are no location-specific population estimates available for harbor seals on the islet off Ayugadak Point. However, the total take estimate of harbor seals in Table 2 (above) already takes proposed personnel activities, such as boat operation and bait station installation, into account. The harbor seal take estimate from Table 2 (above) includes any harbor seals also present on the islet.

Table 3. Estimated number of Steller sea lions affected by bait station installation visits to the islet near Ayugadak Point, August and October.

Species	# of Animals	# of take events per animal	Pups	Subadults	Subadults	Adults	Adults	Total # of Takes
Steller sea lion	320	2	1	10	0	9	1	42

If project crews are not able to visit the islet off Ayugadak Point during either of the proposed planned visits in August and October, the islet would be aerially treated at the same time at Rat Island in October. The aerial broadcast would require approximately 15 minutes of flight time, but would likely disturb all animals present at the time. Survey numbers from the NMFS survey in 2005 indicate the presence of 83 pups. By October, the pups will be of an adequate size to avoid being trampled by other animals and largely independent of their mothers. NMFS survey data was increased to allow for potential population growth and then used to calculate the number of animals affected by an aerial treatment of the islet in the table below.

Table 4. Estimated number of Steller sea lions affected by possible aerial broadcast of the islet near Ayugadak Point, October.

Species	# of Animals	# of take events per animal	Pups	Subadults	Adults	Total # of Takes
Steller sea lion	320	1	100	0	220	320

The distribution of pinnipeds hauled-out along the shorelines is not even between sites or at different times of the year. The number of marine mammals disturbed will vary by month and location, and, compared to animals hauled-out on the shoreline farther away from proposed operations, only those animals hauled-out closest to the actual proposed operation sites are likely to be disturbed by the presence of field crew personnel activities and alter their behavior or attempt to move out of the way.

As discussed earlier, the take estimates consider an animal to have been harassed if it moves away any distance in response to the presence of field crew personnel, watercraft, and/or aircraft, or if the animal is already moving and changed direction. Based on past observations and assuming a maximum level of incidental harassment of marine mammals at each site during periods of visitation, NMFS estimates that the maximum total possible numbers of individuals that will be incidentally harassed during the effective dates of the proposed IHA would be 385 Steller sea lions, and 100 Pacific harbor seals may be taken by incidental harassment as a result of this activity.

The population size of the U.S. western stock of Steller sea lions is estimated to be 44,780, with a minimum population estimate of 38,988 animals (Angliss and Outlaw, 2007). Population estimates for the U.S. Gulf of Alaska stock of Pacific harbor seals range from a minimum of 44,453 to an average of 45,975 animals (Angliss and Outlaw, 2007). The estimated total possible number of individuals that will be incidentally harassed during the proposed project is 0.009 and 0.002 percent of the respective Steller sea lion and harbor seal U.S. stock populations for these species. NMFS has determined that these are small numbers, relative to population estimates, of Steller sea lions and Pacific harbor seals.

Anticipated Impacts to Subsistence Users

In the Aleutian Islands, rural residents harvest Steller sea lions and Pacific harbor seals for subsistence purposes. The proposed rat eradication operations described in the EA should have no effect on those subsistence uses. Rat Island is uninhabited and is located more than 322 km (200 mi) from the nearest rural community of Adak, Alaska. The subsistence resources used by rural residents in the Aleutian Islands are harvested near the islands where the communities are located. Rat Island is not known to have been used for subsistence purposes since the 1800's.

Anticipated Impact of the Proposed Activity upon Marine Mammal Habitat

NMFS anticipates the proposed rat eradication operations described in the IHA application and this document will result in no impacts to the habitat of marine mammals in the Rat Island area beyond rendering the areas immediately around each of the baiting application and broadcasting sites less desirable as haul-out sites for a short time period during the length of the action. Helicopter and field crew operations will occasionally need to occur within the Steller sea lion “no-entry zones” established by 50 CFR 223.202. Although Level B harassment is expected to occur in some instances, these proposed activities will not result in the physical alteration of habitat or lead to any effects on the prey base of Steller's sea lions or harbor seals. The proposed rat eradication project should not result in the loss or modification of marine mammal habitat and the application of rodenticide bait is not likely to affect marine mammals during the described operations.

Proposed Mitigation

Several mitigation measures to reduce the potential for harassment from rat population eradication operations would be (or are proposed to be implemented) implemented as part of the proposed USFWS activities. The risk of injury or mortality would be avoided with the following proposed measures.

Timing

The proposed rat eradication program will include all measures possible to minimize marine mammal disturbance. This will be especially critical during periods when Steller sea lions and harbor seals are giving birth, mating, rearing young, and molting. Disturbances to females with dependent pups (in the cases of Steller sea lions and Pacific harbor seals) will be mitigated to the greatest extent practicable by avoiding visits to baiting sites with resident pinnipeds during periods of breeding, lactation, and molting. During this period, proposed rat eradication operations would be limited to sites where pinniped breeding, post-partum nursing, and molting does not occur.

The reproductive period for Steller sea lions is generally late May through early July, with a peak in the second and third weeks of June (Pitcher and Calkins, 1981; Gisiner, 1985). Pups stay on land for about two weeks, after which they spend increasing time in nearshore waters until they begin to disperse from rookeries to haul-outs with females at about 2.5 months of age (Raum-Suryan et al., 2004; Maniscalco et al., 2002, 2006). In the Aleutian Island area, most pupping is complete by the last week of June and dispersal should occur by mid-September. Molting in Steller sea lions varies by age and sex and is known to last about 45 days. Juveniles molt first, followed by adult females, bulls and pups (Daniel, 2003). The molt should be nearly completed during the proposed planned bait application period.

Harbor seals typically give birth during May and June. Pups are usually weaned within a month and no longer need to be close to their mothers. The peak molting period occurs between August and September (Jemison and Kelly, 2001; Daniel et al., 2003).

Conducting proposed bait application operations after marine mammal breeding and molting is complete reduces the potential for disturbances to these species during the sensitive periods of breeding, pup rearing, and molting. Limiting visits to the breeding, lactation, and molting sites to periods when these activities do not occur will reduce the possibility of incidental harassment and the potential for injury or mortality of dependent Steller sea lion pups and Pacific harbor seals to near zero.

Proposed Operations

Mitigation of the impacts on affected pinnipeds requires that field crew personnel are judicious in the route of approach to haul-out sites and/or rookeries, avoiding close contact with pinnipeds hauled-out on shore. In no case will marine mammals be deliberately approached by field crew personnel, and in all cases every possible measure will be taken to select a pathway of approach to baiting sites that minimizes the number of marine mammals harassed. After each visit to a given baiting site, the site will be vacated as soon as possible so that it can be re-occupied by hauled-out marine mammals that may have been disturbed by the presence of field crew personnel.

Steller sea lions have a persistent haul-out at Krysi Point at the west end of Rat Island and a rookery on the islet off Ayugadak Point. Steller sea lions are likely to haul-out at other locations on Rat Island as well. During staging operations, helicopter flight lines will avoid the rookery, the known haul-out sites discovered prior to helicopter operations. Unlike during staging, it will be more difficult to avoid known haul-out sites on Rat Island with the helicopter during bait application because of the need for thorough coverage of the island.

Disturbance from installation of bait stations on the islet off Ayugadak Point is likely to be limited to the few-hour period when field crew personnel are present on the island. To prevent disturbance to the rookery, the islet will be approached slowly in a small boat, from the side of the island opposite and out of site of the rookery. This will prevent any possibility of stampede. While on the islet, personnel will remain out of sight of the rookery and conduct the installation as quickly as possible.

If a successful installation is completed in August, the bait stations on the islet will need to be replenished in October. Again, the approach to the island will be slow, and opposite the rookery. A few non-breeding animals could be displaced during the bait station check. If it is not possible to land a skiff of the islet, the island will be baited with the helicopter as described in the EA and IHA application. The helicopter baiting will likely be completed in approximately 15 minutes and disturbance to Steller sea lions is likely to be very short term.

Harbor seals will also be avoided to the greatest extent possible during helicopter operations. During staging operations, project managers will plan helicopter flight lines and boat travel to minimize the potential for disturbance to harbor seal haul-outs known from existing databases and surveys conducted prior to the operations. Unlike during staging it will be more difficult to avoid known haul sites on Rat Island with the helicopter during bait application because of the need for thorough coverage of the entire island.

Field Crew Personnel

The Steller sea lion haul-out at Krysi Point on Rat Island will be avoided by personnel involved with this proposed project. The sporadic personnel presence and temporary infrastructure installations that may be necessary near harbor seal haul-outs during both staging and bait application operations may result in localized disturbances, although this is much less likely to disturb animals than proposed helicopter overflights. The camps and staging areas themselves will be well inland and will have negligible impacts on Steller sea lions and harbor seals hauled out on the coastline.

Proposed Monitoring and Reporting

When marine mammals are encountered during the project, personnel will record information regarding species, distribution, behavior, and number of animals. When conditions permit, information regarding sex, age (pup, sub-adult, adult) and any marked animals will also be recorded. As part of the proposed monitoring, USFWS will record the numbers of disturbed animals that flush into the water, the number that move more than 1 m (3.3 ft), but do not enter the water, and the number that become alert and move, but do not move more than 1 m. Upon completion of the project, this information will be compiled and provided to NMFS.

Aircraft and personnel activities related to the proposed project will be coordinated to reduce potential take. The staff of AMNWR and their partners will evaluate incidental take and stop any operations should the potential for incidental take be too great.

Proposed monitoring requirements in relation to USFWS rat eradication operations will include observations made by the applicant and field crew personnel associated with the action. Information recorded will include species counts (with numbers of pups), numbers of observed disturbances, and descriptions of the disturbance behaviors during the proposed rat eradication operations. Observations of unusual behaviors, numbers, or distributions of pinnipeds on Rat Island will be reported to NMFS during and after the project, so that any potential follow-up observations can be conducted by the appropriate personnel. In addition, observations of tag-bearing pinniped carcasses as well as any rare or unusual species of marine mammals will be reported to NMFS.

If at any time injury or death of any marine mammal occurs that may be a result of the proposed rat population eradication operations, USFWS will suspend baiting application and broadcasting activities and contact NMFS immediately to determine how best to proceed to ensure that another injury or death does not occur, and to ensure that the applicant remains in compliance with the MMPA.

A draft final report must be submitted to NMFS within 90 days after the conclusion of the field season. The report will include a summary of the information gathered pursuant to the monitoring requirements set forth in the IHA. A final report must be submitted to the Regional Administrator within 30 days after receiving comments from NMFS on the draft final report. If no comments are received from NMFS, the draft final report will be considered to be the final report.

ESA

For the reasons already described in this Federal Register Notice, NMFS has determined that the described rat population extermination operations and the accompanying IHA may have an effect on species or critical habitat protected under the ESA (specifically, the Steller sea lion). Therefore, consultation under Section 7 is required and will be concluded prior to issuance of an IHA.

National Environmental Policy Act (NEPA)

USFWS prepared an Environmental Assessment (EA) of Restoring Wildlife Habitat on Rat Island, AK, and a Finding of No Significant Impact (FONSI), which analyzed the proposed issuance of an IHA for these activities and operations. A copy of the EA and FONSI are available upon request (see ADDRESSES). NMFS is reviewing this EA and will either adopt it or prepare its own NEPA document before making a determination on the issuance of an IHA to the USFWS on this activity.

Conclusions

Based on the USFWS' application, as well as the analysis contained herein, NMFS has preliminarily determined that the impact of the described rat extermination at Rat Island will result, at most, in a temporary modification in behavior by small numbers of Steller sea lions and Pacific harbor seals, in the form of head alerts, movement away from personnel, watercraft and aircraft, and/or flushing from the beach. In addition, no take by injury or death is anticipated, and take by harassment will be at the lowest level practicable due to incorporation of the mitigation measures mentioned previously in this document. NMFS has further preliminarily determined that the anticipated takes will have a negligible impact on the affected species and not have an unmitigable adverse impact on subsistence uses of marine mammals.

Proposed Authorization

NMFS proposes to issue an IHA to the USFWS for the harassment of Steller sea lions and Pacific harbor seals incidental to non-native rat population extermination operations, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.

Dated: June 12, 2008.

Tammy C. Adams,

Acting Chief, Permits, Conservation, and Education Division, Office of Protected Resources, National Marine Fisheries Service.