ENDANGERED SPECIES ACT

- SECTION 7 CONSULTATION

BIOLOGICAL OPINION

AGENCY: Minerals Management Service

National Marine Fisheries Service

ACTIVITY: Oil and Gas Leasing and Exploration Activities in the U.S. Beaufort and Chukchi
Seas, Alaska; and Authorization of Small Takes Under the Marine Mammal Protection Act

CONSULTATION CONDUCTED BY: National Marine Fisheries Service

APPROVED BY:

DATE ISSUED:Biological Opinion

The U.S. Minerals Management Service (MMS ) and NOAA Fisheries, Office of Protected Resources, have formally consulted National Ma rine Fisheries Service, Alaska Region, on the potential effects of oil and gas leasing and exploration in the U. S. Beaufort Sea and Chukchi Seas, and authorization of “sma ll take” permits under section 101 (a)(5) of the Marine Mammal Protection Act, as amended. This opinion consid ers the effects of these actions on threatened and endangered species under the jurisdiction of NOAA Fisherie s. In formulating this Biological Opinion, NOAA Fisher ies used information pres ented in the MMS’s 2008 Supplement to the 2006 Biological Evaluation of the Potential Effects of Oiland Gas Leasing and Exploration in the Alaska OCS Beaufo rt Sea and Chukchi Sea Planning Areas on Endangered Bowhead Whales (Balaena mysticetus) , Fin Whales ( Balaenoptera physalus) , and Humpback Whales ( Megaptera novaeangliae) , NMFS’s 2006 Draft Recovery Plan for Fin

Whales , NMFS’s 1991 Recovery Plan for Humpback Whales , NMFS’s 2008 Marine Mammal Stock Assessment Reports , reports from the International Whaling Commission along with other research relating to bowhead whal es and information provided by NOAA

= s National Marine Mammal Laboratory, the North Slope Borough, th e Alaska Eskimo Whaling Commission, and the traditional knowledge of th e Alaskan Eskimo community.

Consultation History Pursuant to requirements under the Endangere d Species Act of 1973, as amended (ESA), Minerals Management Service (MMS) has prev iously consulted with the National Marine Fisheries Service (NMFS) on the potential effects of oil and gas leasing and exploration in the Arctic, including activities in the Beaufort S ea and Chukchi Sea Planning Areas. Between 1980 and 1987, inclusive, MMS and NMFS repeatedly consulted on lease sales in the Beaufort Sea, Chukchi Sea, and Hope Basin Planning Areas. Between 1982 and 1987, inclusive, NMFS issued seven Biological Opinions related to Outer Continental Shelf (OCS) lease sales. In November 1988, NMFS concluded an incremental step consultation; the Arctic Regional Biological Opinion (ARBO), which concerned leas ing and exploration activities in the Arctic Region (Beaufort Sea, Chukchi Sea, and Hope Basin OCS Pla nning Areas). Because of the removal of the gray whale from the list of threat ened and endangered specie s, the availability of new information on the potential impacts of o il and gas-related noise on bowhead whales, the use of new seismic survey technology in the Arct ic, and trends in OCS activities in the Arctic Region, this consultation was re-i nitiated in 1999. Due to lack of industry interest in the Chukchi Sea and Hope Basin Plan ning Areas at that time this consultation concerned leasing and exploration activities only in the Beaufort S ea Planning Area. A revi sed Biological Opinion for Oil and Gas Leasing and Exploration Activi ties in the Beaufort Sea was issued May 25, 2001. The action area for that opinion was defined as the Alaskan Beaufort Sea Planning Area, extending from the Canadian border to the Barrow area. The 2001 Biological Opinion concluded that oil and gas leas ing and exploration in the Be aufort Sea was not likely to jeopardize the continued existence of bowhead whales.

Due to industry response to MMS’ recent Beaufort Sea lease sale s and call for information and nominations in the Chukchi Sea, and based on discussions with industry, MMS requested reinitiation of consultation in 2006 so that the area of coverage would included OCS planning

areas in both the Beaufort and Chukchi Seas. A revised opinion was issued in March 2006.

1Recently, monitoring by industry has indicated the presence of humpback and, possibly, fin whales in the action area. Responding to this new information, MMS requested re-initiation of consultation on May 8, 2008, and provided a Biological Evaluation of the potential consequences of their actions to these species.

I. DESCRIPTION OF THE PROPOSED ACTION This opinion will address oil and gas leasing and exploration by the U.S. Department of the Interior, MMS, on the Outer Continental Shelf (OCS ) waters of the Chukchi and Beaufort Seas. Its purpose is to provide an assessment of t hose actions on the continued existence of the bowhead whale, humpback whale, and fin whale, as well as to provide meas ures to conserve the species and mitigate impact. Federal oil and gas leasing consists of several stages, or increments; 1) leasing and expl oration, 2) developmen t, production, and transportation, and 3)

abandonment. The MMS offers leases on th e OCS through periodic sales. Exploration activities may occur prior to or after such sales, while later phases of leasing would all be postlease actions. Various actions may be associat ed with each phase of the leasing process.

Leasing and Exploration * Seismic geophysical surveys * High-resolution and shallow hazard surveys * Exploratory drilling using various platforms * Boat and aircraft activity

Development, production, and transportation * Drilling from artificial islands, drilling platforms, or drill ships * Pipelines * Tankering

Abandonment * Rig demobilization

* Platform removal

* Site restoration

This consultation as it relates to the MMS actio ns will address the first of these incremental steps: leasing and exploration. Subseque nt phases of OCS development (production, transportation, and abandonment) will require add itional consultation. This is due in part to uncertainty at this time and the many variables associated with individua l tract development. There is, in fact, considerable chance that economic quantities of recoverable oil may not be discovered, and no subsequent phases would occur. However, some information on the later phases is presented and assessed in this opinion in order to provide an adequate evaluation regarding the reasonable likelihood of the entire action viol ating section 7(a)(2) of the Endangered Species Act, as amended. Should commercially producible quantities of oil be discovered and development and production be proposed, MMS would initiate new formal

consultation. Further consultation would also occu r if additional species were listed or critical habitat designated, if the proposed action were substantially modified, or if significant new

2effects-related information were developed. This Biological Opinion incorporates much of the information presented within the Biological Evaluation (BE) prepared by MMS, as well as pertinent research on bowhead, hu mpback, and fin whales and matte rs related to oil exploration. Traditional knowledge and the observations of Inupiat hunters are presented, along with information gained through sc ientific research. This knowledge contributes, along with scientific information, to a more complete understanding of these issues. A reasonable assessment of potential effects can only be made by considering both these systems of knowledge.

This opinion will also address authorization of the incidental and unintentional taking of fin, humpback, and bowhead whales due to certain oil and gas explorati on activities by NMFS. Section 101 (a)(5) of the Marine Mammal Protection Act (MMPA) , directs the Secretary of Commerce to allow, upon request by U.S. citizen s engaged in a specific activity (other than commercial fishing) in a specifi ed geographical region, the incide ntal but not intentional taking

of small numbers of marine mamm als if certain findings are made . Such authorization may be accomplished through regulations and issuance of letters of authorization under those regulations, or through issuance of an incidental harassment authorization (IHA). These authorizations may be granted only if an activit y would have no more than a negligible effect on the species (or stock) in question, would not have an unmitigable adverse impact on the availability of the marine mammal for subsiste nce uses, and that the permissible method of taking and requirements pert aining to the monitoring and reporti ng of such taking are set forth to ensure the activity will have the least practicable adverse effect on the sp ecies or stock and its

habitat. These authorizations are often re quested for oil and gas activities which produce underwater noise capable of harassing or harmi ng marine mammals. Harassment is a form of taking otherwise prohibited by the MMPA and ES A. While MMS permits issued under the Outer Continental Shelf Lands Act are necessarily confined to Federal waters of the U.S. Outer Continental Shelf, MMPA authorizations may be i ssued for work within State of Alaska waters

of the Chukchi and Beaufort Seas.

The actions, consequence, and environmental e ffects of these MMPA au thorizations are the same as those described here for the oil and ga s leasing and explorati on activities (i.e., the

activities for which an MMPA authorization would be issued). However, the actual consequence of these incidental take authorizations are likely to be less overall than that associated with leasing and exploration, because 1) not all actions may be authorized, 2) these authorizations only apply to uninten tional and incidental takes, 3) illegal activity such as an oil spill cannot be authorized under this program, and 4) the level of authorized take may not result in more than a negligible impact to marine mammals, including these endangered whales.

Term of this Opinion This opinion will be valid upon issuance and rema in in force until re-initiation may become necessary. Consultation will be re-initiated if there are significant changes in the type of exploratory activities occurring, if new information indicates these actions are impacting the bowhead stock or other listed sp ecies/critical habitats to a degr ee or in a manner not previously considered, or if new species ar e listed or critical ha bitat are designated or revised become under

the Act.

3Action Area The action area for purposes of th is Biological Opinion is define d as the Alaskan Beaufort and

Chukchi Seas. The direct and indirect effect s of this action on the endangered fin, humpback, and bowhead whale are expected to be confined to the action area.

Leasing and Exploration Activities The opinion provides an explorati on scenario based on a composite of feasible options that could be developed. The options are the result of discussions within MMS, the State of Alaska, other government agencies, and with industry. Th e locations of existing infrastructure, sites with potential as support facilities, area-resource estimates, and scenarios developed for previous

OCS sales in these waters were all considered in developing this scenar io. A summary of the major exploration assumptions follows:

Exploration Activities in the Beaufort Sea A detailed description of all exploratory activity associated with this action cannot be made at this time, as it will depend on the interests of the oil and gas industr y, oil prices and other economic considerations, and other factors. Ho wever, for purposes of analyses MMS assumes that a maximum of two drilling ri gs would operate at any time, w ith a total of six exploration and six delineation wells expect ed to be drilled over the 8-year exploration period. Exploration activity (seismic su rveys and drilling) will begin w ith seismic surveying in summer of 2006 and continue through 2013, with delinea tion wells drilled through 2014. The type of units that might be used in e xploration drilling would depend on water depth, sea-ice conditions, ice-resistance of the units, and availability of drilling units. Artificial ice islands grounded on the seabed have been used as drilling platforms in shallow water (less than 10 meters [m]), and nearshore operations would be s upported by ice roads over the landf ast ice. Gravel islands are not likely to be constructed for e xploration drilling in OCS waters (generally deeper than 10 m), although older artificial islands or natural shoals c ould be used as a base for temporary gravel or ice islands. Movable platforms resting on the s eafloor likely would be used for exploration drilling. These platforms are designed to with stand winter ice forces , and drilling could be conducted year-round. Bottom-founde d platforms (set on the seafloor) could be used to drill prospects in water depths of 10-20 m, and drills hips or other types of floating platforms would be used in deeper water. These floating syst ems can operate only in open-water and broken-ice conditions and not in midwinter pack-ice conditions . Because mobile ice conditions in deeper water make ice roads unfeasible, deeper water (Far Zone) operations would take place during the summer open-water season and would be supporte d by icebreakers and supply boats. They would be stored in protected inshore areas when not in use.

Based on geologic studies, MMS assumes that exploration and delineation wells generally would test prospects from 3,000-15,000 feet (ft) (914-4,572 m), and a representative exploration-well depth of 7,000 ft (2,133 m). At this depth, each explorator y or delineation well would require 425 short tons of drilling muds (dry weight) an d produce approximately 525 short tons of dry rock cuttings. MMS assumes that 80% of the drilling muds would be recycled, leaving 85 tons of “spent mud” to be discha rged along with all the drill cuttings at each exploration site or disposed of onshore. MMS estimates that 935-1,040 s hort tons (dry weight)

4of drilling muds and 5,775-6,300 short tons (dry we ight) of bore cuttings would need to be disposed of for the exploration and delineation ac tivities for each sale. These materials would be disposed of primarily at the drill site unde r conditions prescribed by the Environmental Protection Agency’s National Pollution Discharg e Elimination System (NPDES) (Clean Water Act of 1977, as amended (33 U.S.C. 1251 et seq.).

High-resolution seismic survey is the preferre d method used by the oil and gas industry to provide required information on shallow hazards, archaeological re sources, and potential benthic communities in support of propos ed exploration and development plans. Typical highresolution seismic survey operations are described in Section IV.

MMS also estimates that no more than seve n 2D/3D seismic surveys would occur in the Chukchi and Beaufort Sea planning areas each year.

Offshore exploration-drilling op erations in the Beaufort Sea may require onshore support facilities such as the following:

• a staging area for construction equipment, drilling equipment, and supplies;

• a transfer point for drilling and construction personnel;

• a harbor to serve as a base for vessels required to support offshore operations; and

• an airfield for fixed-wing aircraft and helicopters.

Typically, a mobile drilling platform used for exploration drilling woul d enter its area of operation fully supplied for the drilling season. Th e level of support-boat traffic would vary by distance from shore and/or support base and wh ether or not the facility can be supported by vehicles using ice roads in the winter.

Ice roads are assumed to be the principal route fo r transporting routine supplies and materials to ice islands and/or nearshore grav el islands. For drilling platform s farther offshore in the brokenice zone, material and supplies would be transp orted by support/supply bo ats (with icebreaking capacity, if necessary) during the open-water season and by helicop ter at all other times. For both types of drilling structures , it is probable that most pe rsonnel would be transported by helicopters. The number of helicopter trips flow n in support of exploration and delineation well drilling is assumed to range from about 90-270 each year, depending on the number of wells (1- 3) that are drilled. For each drilling operation, we assume there would be one flight per day of drilling. The time required to drill an d test a well is about 90 days.

Exploration Activities in the Chukchi Sea Approximately 100,000 line-miles of 2D seismic su rveys have been collected to-date in the Chukchi Planning Area. Add itional 3D surveys have occu rred in 2006, 2007, and are planned for 2008. The number of high energy seismic survey s is expected to decr ease over time as data is collected over most prospects. 3D seismi c surveys can only be conducted during open water (approximately June to November)

. Seismic surveys in the Chukchi will probably be coordinated with surveys in the Beaufort Sea to employ the same vessels. An icebreaker may be used as a support boat and this w ould ensure that the large seismi c vessel could exit the area at

the end of the season. The rate of seismic su rvey may average 20-30 da ys (with downtime) to

5cover a 200-mi 2 area. At normal vessel speeds, the airgun array would produce a sound signal every 10-15 seconds. One or more seismic surveys may be conducted (with down time) during the entire open water period as compatible with mitigation requirements. Each permit may authorize multiple surveys in a planning area. So, surveys in different parts of a planning area may overlap in time.

Based on mapping of the subsurface structures using 3D seismic data, several well locations will be proposed. Prior to drilling deep test wells, high-resolution site-clearance seismic surveys and geotechnical studies will examine the proposed ex ploration drilling loca tions for geologic hazards, archeological features, and biological populations. Site clearance and studies required for exploration will be conducted during the open wa ter season before the drill rig is mobilized

to the site. Such activities are expected to begin in 2008.

Considering water depth and the remoteness of this area, drilling operations are likely to employ drillships with icebreaker support vessels. Wate r depths greater than 100 ft and possible packice incursions during the open water season wi ll preclude the use of bottom-founded drilling platforms. Using drillships allows the operator to temporarily move off th e drill site, if sea or ice conditions require it, and the suspended well is controlled by so-called blow-out-prevention equipment installed on wellheads on the seabed. Bottom-founded platforms that are more permanently installed are better choices for production platforms. Drilling operations are expected to range between 30 and 90 days at di fferent well sites, depe nding on the depth to the target formation, difficulties during drilling, a nd logging/testing operations. Considering the relatively short open water season in the Chukchi (June-November), only 1-2 wells are expected per drilling season. MMS assumes that one well could be drilled, test ed, and abandoned and another well could be started each summer season. Five exploration wells have been drilled todate on the Chukchi shelf and MMS assumes th at 7-14 additional wells will be needed to

discover and delineate the first commercial field.

Seismic geophysical operations will occur durin g exploration phases of leasing for both the Chukchi and Beaufort Seas. The MMS anticipates a maximum of seven (7) 2D/3D marine streamer seismic operations to be conducted an nually in the Chukchi and Beaufort Seas.

In addition to high energy/low resolution seismic work (2D/3D), there will be need for highresolution seismic and other exploratory activitie s which look for shallow hazards, bottom depth and contours, or are otherwise necessary for si te preparation work prior to drilling. These devices use lower energy and sound than 2D/3D se ismic and sound would be less likely to travel

as far.

II. STATUS OF THE SPECIES (RANGEWIDE)

NMFS has determined that the described actions may affect the following species provided protection under the Endangered Species Act of 1973 (16 U.S.C. 1531 et seq .; ESA):

Marine Mammals Fin whale ( Balaenoptera physalus) Endangered Bowhead whale ( Balaena mysticetus ) Endangered

6Humpback whale ( Megaptera novaeangliae) Endangered

This opinion will consider the potential effects of these actions on these species. However, we believe the bowhead whale is most likely to be affected by oil and gas leasing and exploration, and that this species is likely more sensitive to noise and disturbance than are humpback and fin whales. Additionally, there now exists a consid erable database on the Western Arctic bowhead stock and the potential and meas ured impacts to these whales due to oil exploration in the Arctic. Much of this information will be generally applicable to other large balenopterid whales, notably fin and humpback whales. Therefore, the bowhead whale often receives the most attention under this opinion.

Bowhead Whale

ESA Listing History and Status

The bowhead whale was listed as a Federal e ndangered species on June 2, 1970 (35 FR 8495). While five stocks are recognize d, the Western Arctic population of the bowhead whale is the only one known to occur in the act ion area. All further references to the bowhead whale in this document concern only the Western Arctic populati on. No critical habitat has been designated for the species.

Population and Stock Structure The bowhead whale was historically found in all arctic waters of the northern hemisphere. Five populations are currently recognized by the IWC (1992). Three of these populations are found

in the North Atlantic and two in the North Pacific, some or all of which may be reproductively isolated (Shelden and Rugh, 1995). The Spitsbe rgen population is found in the North Atlantic east of Greenland in the Greenland, Kara, and Ba rents Seas. Thought to have been the most numerous of bowhead populations, Woodby and Bodkin (1993) estimate the unexploited population at 24,000 animals. The Spitsbergen bow head is now severely depleted, possibly in the tens of animals (Shelden and Rugh, 1995).

The Davis Strait population is found in Davis Stra it, Baffin Bay, and along the Canadian Arctic Archipelago. This population is separated from the Bering Sea population by the heavy ice found along the Northwest Passage (Moore and R eeves, 1993). The population was estimated to have originally numbered over 11,700 (Woodby and Botkin, 1993) but was significantly reduced by commercial whaling between 1719 a nd 1915. The population is today estimated at 350 animals (Zeh et al. , 1993) and recovery is described as “at best, exceedingly slow” (Davis and Koski, 1980).

The Hudson Bay population, also found in Foxe Ba sin, is differentiated from the Davis Strait population by their summer distribution, rather than genetic or morphological differences (Reeves et al., 1983). No reliable estimate exists fo r this population; however, Mitchell (1977) places a conservative estimate at 100 or less. More recently, estimates of 256-284 whales have been presented for the number of whales within Foxe Basin (Cosens et al. , 1997). There has been no appreciable recove ry of this population.

7The Okhotsk Sea population occurs in the North Pacific off the west ern coast of Siberia near the Kamchatka Peninsula. The pre- exploitation size of this popul ation may have been 3,000 to 6,500 animals (Shelden and Rugh, 1995), and ma y now number somewhere in the 300-400 range, although reliable population estimates are not currently avai lable. It is possible this population has mixed with the Bering Sea population, although the availa ble evidence indicates the two populations are essentially separate (Moore and Reeves, 1993).

Of the five stocks of bowheads whales cu rrently recognizes by th e IWC for management purposes (IWC, 1992), the Western Arctic stock is th e largest, and the only stock to inhabit U.S. waters. All of the stocks except for the Wester n Arctic are “comprised of only a few tens to a few hundreds of individuals” (A ngliss and Outlaw, 2008). Thus, the Western Arctic stock of bowheads is the most robust and viable of surviving bowhead populations. The viability of

bowheads in the Western Arctic stock is critical to the long-term future of the biological species

as a whole.

The Scientific Committee of the IWC previously concluded that the West ern Arctic stock of bowheads comprise a single stock (DeMaster et al., 2000). However, after an in-depth evaluation of available data, the Scientific Committee (IWC, 2004a) concluded that there is temporal and spatial heterogeneity among these bow heads, but analyses do not necessarily imply the existence of subpopulations with limited interbre eding; it was prematur e to draw conclusions about the relative plausibility of any hypotheses about stock structur e or to reject any of them. Subsequently, NMFS and the North Slope Bor ough created a set of fi ve stock-structure hypotheses, modified this set, and currently r ecommends testing of the following hypotheses: (1) a single stock; (2) spatial se gregation; (3) temporal ; (4) feeding; and (5) immigration. After more recent information provided to the IWC Su bcommittee on bowhead, right and gray whales (IWC, 2005b), the subcommittee agree that what is termed the “Oslo Bump” (a significant increase in genetic difference between pairs of whales sampled approximately 1 week apart at Barrow during the fall migration) appears to be a real pattern within the data that are available. However, additional data are needed to determine if these data actually typify the bowhead population, and there is no single hy pothesis adequate to explain th e pattern. Stock structure is unclear at the time of this writing. The IW C will be conducting an Implementation Review focusing on the stock structure of the Western Arctic stock of bowhead with the goal of completing this at the 2007 annual meeting (IWC, 2005a). Two related intersessional workshops, one that occurred in 2005 and one th at will occur in spring 2006, are focusing on this topic (IWC, 2005a,b).

Taylor et al. (2007) examined the plausibility of multiple bowhead whale stocks in the Western Arctic population. They synthesi sed four lines of evidence that related to understanding stock structure: (1) movement and distribution, (2) basic biology, (3) history of commercial whaling, and (4) interpretation of geneti c patterns. The paper reviewed 30 years of research plus contributions from traditional ecological knowle dge. In terms of bowhead biology, bowhead whales have adapted to living in an arctic ecosy stem where ice coverage and food resources vary through time. Taylor et al. ( 2007) concluded that this varying environment makes both the evolutionary reason for multiple breeding stocks within the Bering Sea and the biological feasibility of maintaining separa tion within a relatively small pe lagic area unlikely. There is variability in the timing that indi vidual bowhead whales migrate, in the timing of the peak of the

8migration itself, and in the location of both su mmering and wintering grounds. The variation is a result of both changing environmental cond itions and changes in the whales’ age and reproductive state. Furthermore, the available ar ea for any potential segregation of feeding or breeding groups is well within the ability of individual whales to travel in a few days time. No evidence was found that a small discrete stock, like the Okhotsk Sea stock, is present and killed in any numbers during the spring or autumn migr ation of Western Arctic bowhead whales. No data were found to support risk to a separate feeding group. Ot her insights using genetic data were weak, but nearly all results were consistent with a single stock that is out of equilibrium following commercial depletion. Bowhead whal es being out of genetic equilibrium was supported by differences found between age cohorts, both in empirical data and simulated data. The only significant genetic findings worth furthe r consideration were differences involving St. Lawrence Island. However, the comparisons that were significant involved small sample sizes and could just as well result from genetic pa tterns found between different age cohorts.

At the 2007 IWC meeting in Anchorage, Alaska , the IWC Scientific Committee Sub-committee on Bowhead, Right and Gray Whales concluded after a three year investigation of the stock structure of the Bering-Chukchi-Beaufort popula tion of bowhead whales (as summarized in Taylor et al. (2007)) that th e available evidence best suppor ts a single-stock hypothesis for Western Arctic bowhead whales (IWC 2007).

Woody and Botkin (1993) estimated that the hi storic population abundance of bowheads in the Western Arctic stock was between 10,400 and 23,000 whales in 1848 before the advent of commercial whaling, which severely depleted bo whead whales. They estimated that between 1,000 and 3,000 animals remained in 1914 near the end of the commercial-whaling period. Based on both survey data and the incorporation of acoustic data, the a bundance of the Western

Arctic stock of bowhead whales was estim ated between 7,200 and 9,400 individuals in 1993 (Zeh, Raftery, and Schaffner, 1995), with 8,200 as the best population estimate. An alternative method produced an estimate of 7,800 individuals, with a 95% confid ence interval of 6,800- 8,900 individuals. Data indicate th at the Western Arctic stock increased at an estimated rate of about 3.1% (Raftery, Zeh, and Givens, 1995) to 3.2% (Zeh, Raftery, an d Schaffner, 1995) per year from 1978-1993. The estimated increase in the population size most likely is due to a combination of improved data and better census t echniques, along with an actual increase in the population.

George et al. (2004) estimated abundance in2001 to be 10,470 (SE = 1,351) with a 95% confidence interval of 8,100-13,500. This estimate indicates a substantial increase in population abundance since 1993 and suggests that populati on abundance may have reached the lower limits of the historical population estimate. Ze h and Punt (2004, cited in Angliss and Outlaw, 2005) provided a slightly revised population estimate of 10,545 CV(N) =0.128 to the IWC in 2004. This is the best estimate currently us ed by NMFS in the 2008 Stock Assessment Reports (Angliss and Outlaw 2008). George et al. (2004) estimated that the annual rate of increase (ROI) of the population from 1978-2001 was 3.4% (95% CI 1.7%-5%) and Brandon and Wade (2004) estimate an ROI of 3.5% (95% CI 2.2-4.9%). The number of calves (121) counted in 2001 was the highest ever recorded for this popu lation and this fact, when coupled with the estimated rate of increase, suggests a steady r ecovery of this populati on (George et al., 2004).

9This steady recovery is likely due to low anthropogenic mortality, a relatively pristine habitat, and a well-managed subsisten ce hunt (George et al., 2004).

Reproduction, Survival and Non- Human Sources of Mortality Information gained from the various approaches at aging the Western Arctic stock of bowhead whales and estimating survival rates all sugges t that bowheads are slow -growing, late-maturing, long-lived animals with survival rates that are currently high (Zeh et al., 1993; see below). Female bowheads probably become sexually mature at an age exceeding 15 years, from their late teens to mid-20’s (Koski et al., 1993) ( Schell and Saupe, 1993: about 20 years). Their size at sexual maturity is about 12.5-14.0 meters (m ) long, probably at an age exceeding 15 years (17-29 years: Lubetkin et al., 2004 (cited in IWC, 2004b). Most males probably become sexually mature at about 17-27 years (Lubetkin et al., 2004 cited in IWC, 2004b). Schell and Saupe (1993) looked at baleen pl ates as a means to determine the age of bowhead whales and

concluded that bowheads are slow -growing, taking about 20 years to reach breeding size. Based on population structure and dynamics , Zeh et al. (1993) also conc luded that the bowhead is a late-maturing, long-lived animal (George et al., 1999) with fairly low mortality. Photographic recaptures by Koski et al. (1993) also suggested a dvanced age at sexual maturity of late teens to

mid-twenties.

Mating may start as early as Janua ry and February, when most of the population is in the Bering Sea but has also been reported as late as September and earl y October (Koski et al., 1993). Mating probably peaks in March-April (IWC, 20 04b). Gestation has been estimated to range between 13 and 14 months (Nerini et al., 1984; Reese et al., 2001) and between 12 and 16 months by Koski et al. (1993) (see also informa tion and discussion in IWC, 2004b). Reese et al. (2001) developed a nonlinear model for fetal grow th in bowhead whales to estimate the length of gestation, with the model indicating an average length of gestation of 13.9 months. Data indicate most calving occurs duri ng the spring migration when whal es are in the Chukchi Sea. Koski et al. (1993) reported that calving occu rs from March to early August, with the peak probably occurring between early April and the e nd of May (Koski et al., 1993). The model by Reese et al. (2001) also indicated that conception likely occurs in early March to early April, suggesting that breeding occurs in the Bering Sea. The concepti on date and length of gestation suggests that calving is likely to occur in mid-May to mid-June, when whales are between the Bering Strait and Point Barrow (in the Chukchi Sea). Reese et al. (2001) said this is consistent

with other observations in the region, including: (a) relativel y few neonate-cow pairs reported by whalers at St. Lawrence Island; (b) many neonates seen during the whale census in late May; (c) relatively few term females taken at Barrow; (d) taken females with term pregnancies appeared close to parturition; a nd (e) most of the herd believed to have migrated past Barrow by late May. Females give birth to a si ngle calf probably every 3-4 years.

Discussion during the in-depth as sessment by the IWC (2004b) also indicated that differences in lipid content between females of the same length and size are attributable to pregnant versus nonpregnant females. This may imply a high bi ological cost of reproduc tion, a fact noteworthy in considering the potential imp act of excluding females from f eeding areas. George et al. (2004) estimated pregnancy rates of 0.333/year and an estimated in terbirth interval of 3.0 years using data from postmortem examinations of whales landed at Barrow and Kaktovik in the

winter.

10There is little information regarding causes of natural mortality for Western Arctic bowhead whales. Bowhead whales have no known pred ators except, perhaps, killer whales and subsistence whalers. The frequency of attacks by killer whales probably is low (George et al., 1994). A relatively small number of whales likely di e as a result of entrapment in ice (Philo et al., 1993). Little is known about the effects of microbial or vi ral agents on natural mortality.

The discovery of traditional whaling tools recovered from five bowheads landed since 1981 (George et al., 1995) and estimates of age using aspartic-acid racemization techniques (George et al., 1999) both suggest bowheads can live a very long time, in some instances more than 100 years. The oldest harvested females whose ages were estimated using corpora albicans accumulation to estimate female age were more than 100 years old (George et al., 2004, cited in IWC, 2004b). Discussion in the IWC (2004b) indi cated that neither lifespan nor age at sexual maturity is certain. Lifespan may be greater than the largest estimates.

Using aerial photographs of naturally marked bowheads collected between 1981 and 1998, Zeh et al. (2002:832) estimated “the posterior mean for bowhead survival rate...is 0.984, and 95% of the posterior probability lies between 0.948 and 1.” They noted that a high estimated survival

rate is consistent with ot her bowhead life-history data.

Distribution and Habitat Use The Western Arctic stock of bowheads generally occur north of 60° N. and south of 75° N. (Angliss and Outlaw, 2005) in the Bering, Chukchi, and Beaufort seas. They have an affinity for ice and are associated with relatively heavy ice cover and shallow continental shelf waters for much of the year. Bowhead whales of the We stern Arctic stock overwinter in the central and western Bering Sea. Most mating probably occurs in the Bering Sea. The amount of feeding in the Bering Sea in the winter is unknown as is the amount of feeding in the Bering Strait in the fall (Richardson and Thomson, 2002). In the Beri ng Sea, bowheads frequent the marginal ice zone, regardless of where the z one is, and polynyas. Important winter areas in the Bering Sea include polynyas along the northern Gulf of Anadyr, south of St . Matthew Island, and near St. Lawrence Island. Bowheads congregate in these polynyas before migrating (Moore and Reeves, 1993).

Observations by Mel’nikov, Zelensky, and Aina na (1997) from shore-ba sed observations of waters adjacent to the Chukotka Peninsula in 1994-1995 indicate th at bowheads winter in the Bering Sea along leads and polynyas adjacent to th e Asian coastline. Mel’nikov, Zelensky, and Ainana (1997) summarized that in years when there is little winter i ce, bowheads inhabit the Bering Strait and potentially inhabit southern portions of the Chukchi Sea.

During their southward migration in the autumn, bowheads pass through the Bering Strait in late October through early November on their way to ove rwintering areas in the Bering Sea. Large

numbers of bowheads were taken in June a nd July during commercial whaling over large portions of the northwestern and northcentral Bering Sea (Figure 1b in Dahlheim et al., 1980, from Townsend, 1935).

11Some, or nearly all of the bowheads that winter in the Bering Sea migrate northward through the Bering Strait to the Chukchi Sea and through the Alaskan Beaufort Sea to summer feeding grounds in the Canadian Beaufort Sea. The bowhead northward spring migration appears to coincide with ice breakup and probably begins most years in April (possibly late March depending on ice conditions) and early May. It is thought to occur after the peak of breeding,

which is believed to occur in March- April (C. George, cited in IWC, 2004b).

Bowheads congregate in the polynyas before migrating (Moore and Reeves, 1993; Mel’nikov, Zelensky, and Ainana, 1997). Large numbers of bow heads were taken in June and July during commercial whaling over large por tions of the northwestern and northcentral Bering Sea (Figure 1b in Dahlheim et al., 1980, from Townsend, 1935) . Bowheads migrate up both the eastern and western sides of the Bering Strait in th e spring (Mel’nikov, Zele nsky, and Ainana, 1997; Mel’nikov et al., 2004). They pass through the Beri ng Strait and eastern C hukchi Sea from late March to mid-June through newly opened leads in the shear zone between the shorefast ice and the offshore pack ice. During spring aerial surveys in the late 1980’s, bowheads were documented to be migrating in shorefast leads and polynyas up the coast of northwestern Alaska (see Figures 4 and 5 in Mel’ni kov, Zelensky, and Ainana, 1997).

Based on shore-based surveys in 1999-2001, Mel’ni kov et al. (2004) observe d that the start of spring migration from the Gulf of Anadyr varies between cold and mild years by up to 30 days, but in both instances, continues at least until June 20. Mel’nikov et al. (2004) also reported that weather influenced migration, with migration se eming to stop when there were storms or high winds in the western Bering Strait or at the exit from the Gulf of Anadyr.

The migration past Barrow takes place in pulses in some years (e.g., in 2004) but not in others (e.g., 2003) (Koski et al., 2004, cite d in IWC, 2004b). At Barrow, the first migratory pulse is typically dominated by juveniles. This patter n gradually reverses and by the end of the migration, there are almost no juveniles. Curren tly, the whales are first seen at Barrow around April 9-10. In later May (May 15-June), large wh ales and cow/calf pairs ar e seen (H. Brower, in USDOC, NOAA and NSB, 2005; IWC, 2004b). Koski et al. (2004b) found that females and

calves constituted 31-68% of the total number of whales seen during the last few days of the migration. Their rate of spring migration was slow er and more circuitous than other bowheads. Calves had shorter dive duration, surface duration, and blow interval than their mothers. Calf blow rate was nearly 3 times that of their mother s. Most calving probabl y occurs in the Chukchi

Sea. Some individuals or subset of the population may summer in the Chukchi Sea.

Several studies of acoustical a nd visual comparisons of the bowhead’s spring migration off

Barrow indicate that bowheads al so may migrate under ice within several kilometers of the

leads. Data from several observers indicate th at bowheads migrate underneath ice and can break through ice 14-18 centimeters [cm] (5.5-7 inches [in]) thick to breathe (George et al., 1989; Clark, Ellison, and Beeman, 1986). Bowheads ma y use cues from ambient light and echoes from their calls to navigate under ice and to dist inguish thin ice from multiyear floes (thick ice). After passing through Barrow from April through mid-June, they move easterly through or near offshore leads. East of Point Barrow, the lead systems divide into many branches that vary in location and extent from year to year. The sp ring-migration route is offshore of the barrier

islands in the central Alaskan Beaufort Sea.

12Bowheads arrive on their summer feeding groun ds near Banks Island from mid-May through June (July: IWC, 2005b) and remain in the Cana dian Beaufort Sea and Amundsen Gulf until late August or early September (Moore and Reeves, 1993). Bowhead whales are seen also in the central Chukchi Sea and along the Chukotka coast in July and August. They may occupy the northeastern Chukchi Sea in late summer more regularly than commonly believed (Moore, 1992; USDOC, NOAA, and NSB, 2005), but it is unclear if these are “early-a utumn” migrants or

whales that have summered ne arby (Moore et al., 1995) or else where. Bowhead whales have been observed near Barrow in the mid-summer (e.g., Brower, as cited in USDOI, MMS, 1995). Eight bowheads were observed near Barrow on July 25, 1999, 2 at 71° 30’ N., 155° 40’W. to 155° 54’ W. from a helicopter during a search, and six at 71° 26’ N., 156° 23’ W. from the bridge of the icebreaker Sir Wilfrid Laurier (M oore and DeMaster, 2000) . Moore and DeMaster (2000:61) noted that these observations are consis tent with Russian scie ntist suggestions that

“... Barrow Canyon is a focal feeding area for bowhead s and that they ‘move on’ from there only when zooplankton concentrations disperse (Mel’nikov et al. 1998) ” and consistent with the time frame of earlier observations summarized by Moore (1992.)

Some biologists conclude that almost the entire Bering Sea bowhead population migrates to the Beaufort Sea each spring and that few whales, if any, summer in the Chukchi Sea. Incidental sightings suggest that bowhead whales may occupy the Chukchi Sea in the summer more regularly than commonly believed. Moore (1992) summarized obs ervations of bowheads in the

northeastern Chukchi in late su mmer. Other scientists maintain that a few bowheads swim northwest along the Chukotka coast in late spring and summer in the Chukchi Sea. Observation by numerous Russian authors (cited in Mel’nikov , Zelensky, and Ainana [1997:8]) indicates that

bowheads occur in waters of the Chukchi S ea off the coast of Chukotka in the summer.

Harry Brower, Jr. observed whales in the Ba rrow area in the middle of the summer, when hunters were hunting bearded seals on the ice ed ge (Brower, as cited in USDOI, MMS, 1995). The monitoring program conducted while towing the single steel drilling caisson to the McCovey location in 2002 reco rded five bowhead whales off Point Barrow on July 21.

Recent systematic data about bowhead distri bution and abundance in the Chukchi Sea OCS Planning Area are lacking. The MMS funded large-scale surveys in this area when there was oil and gas leasing and exploration, but while surveys in the Beaufort Sea have continued, the last surveys in the Chukchi Sea were about 15 years ago.

Bowheads found in the Bering and Chukchi Seas in the summer may be part of the expanding Western Arctic stock (Rugh et al. 2004), as refe renced in Angliss, DeMaster, and Lopez, 2001).

Evidence indicates that the number of bowheads in the Western Arctic stock has increased substantially since the time of the surveys (Brandon and Wade, 2004, cited in IWC, 2004b). Temporal and spatial patterns of distributi on also may be modified. Conversely, earlier information may have inferred less variability in distribution than actually existed.

Those bowheads that have been summer feedi ng in the Canadian Beaufort Sea begin moving westward into Alaskan waters in August and September. While few bowheads generally are seen in Alaskan waters until the major porti on of the migration takes place (typically mid13September to mid-October), in some years bowhead s are present in substantial numbers in early September (Greene and McLennan, 2001; Treac y, 1998). In 1997, Treacy (1998) reported sighting 170 bowheads, including 6 calves, betw een Cross Island and Kaktovik on September 3 during the first flight of the survey that year . In 1997, Treacy (1998) observed large numbers of bowheads between Barrow and Cape Halkett in mid-September. Large numbers were still present between Dease Inlet and Barrow in early October (although they may not have been the same individuals).

There is some indication that the fall migrati on, just as the spring migration, takes place in pulses or aggregations of whales (Moore and Reeves, 1993). Eskimo whalers report that smaller whales precede large adults and cow-calf pair s on the fall migration (Braham et al., 1984, as reported in Moore and Reeves, 1993). During th e autumn migration Koski and Miller (2004, cited in IWC, 2004b) found decreasing proportions of small whales and increasing proportions of large whales as one moved offshore. “Mothe rs and calves tended to avoid water depths less than (<) 20 m.” (Koski and Miller, cited in IW C, 2004b:14). These authors also found that in the Central Beaufort Sea in late August, the vast majority of the whales were subadults and this percentage declined thro ughout the autumn to about 35% by early October. They reported that mother/calf pairs “arrived in September and were common until early October” (Koski and Miller, 2004, cited in IWC, 2004b).

Inupiat whalers estimate that bowheads take abou t 2 days to travel from Kaktovik to Cross Island, reaching the Prudhoe Bay area in the central Beaufort Sea by late September, and 5 days

to travel from Cross Island to Point Barro w (T. Napageak, 1996, as cited in NMFS, 1999).

Individual movements and aver age speeds (approximately 1.1-5.8 kilometers per hour [km/h]) vary widely (Wartzog et al., 1990; Mate, Krutzikowsky, and Winsor, 2000). Much faster speeds (e.g., up to 9.8 + 4.0 km/h) were estimated for bo wheads migrating out of the Gulf of Anadyr during the northward spring migration (Mel’nikov et al., 2004).

Wartzog et al. (1989) placed radio tags on bowheads and tracked the tagged whales in 1988. One tagged whale was tracked for 915 km as it migr ated west at an average speed of 2.9 km/h in ice-free waters. It traveled at an average speed of 3.7 km/h in relatively ice-free waters and at an average speed of 2.7 km/h through eight-tenths ice cover and great er. Another whale traveled 1,291 km at an average speed of 5.13 km in ice- free waters but showed no directed migratory movement, staying within 81 km of the tagging site . Additional tagged whales in 1989 migrated 954-1,347 km at average speeds of 1.5-2.5 km/h (Wartzog et al., 1990). Mate, Krutzikowsky, and Winsor (2000) tagged 12 juvenile bowhead whal es with satellite-monito red radio tags in the

Canadian Beaufort Sea. The whale with th e longest record traveled about 3,886 km from

Canada across the Alaskan Beaufort Sea to the Chukchi Sea off Russia and averaged 5.0 km/h. This whale’s speed was faster, t hough not significantly faster, in heavy ice than in open water.

Oceanographic conditions can vary during the fall migration from open water to more than ninetenths ice coverage. The extent of ice cover may influence the timing or duration of the fall migration. Miller, Elliot, and Richardson (1996 ) observed that whales within the Northstar region (long. 147 ° -150 ° W.) migrate closer to shore in light and moderate ice years and farther offshore in heavy ice years, with median distances offshore of 30-40 km (19-25 miles [mi]) in

14both light and moderate ice years and 60-70 km (37-43 mi) in heavy ice years. Moore (2000)

looked at bowhead distribution and habitat selecti on in heavy, moderate, and light ice conditions in data collected during the autumn from 1982-1991. This study concluded that bowhead

whales select shallow inner-shelf waters duri ng moderate and light i ce conditions and deeper slope habitat in heavy ice conditions. During th e summer, bowheads selected continental slope

waters and moderate ice condi tions (Moore, DeMaster, and Da yton, 2000). Interseasonal depth and ice-cover habitats were sign ificantly different for bowhead whales. Ljungblad et al. (1987) observed during the years from 1979-1986 that the fall migration extended over a longer period, that higher whale densities were estimated, and that daily sighti ng rates were higher and peaked later in the season in light ice year s as compared to heavy ice years.

Fall aerial surveys of bowhead whales in the Alaskan Beaufort Sea have been conducted since 1979 by the Bureau of Land Management and th e MMS (Ljungblad et al., 1987; Treacy, 1988- 1998, 2000). Over a 19-year period (1982-2000), th ere were 15 years with some level of offshore seismic exploration and/or drilling activity and 4 years (1994, 1995, 1999, and 2000) in which neither offshore activity took place during Se ptember or October. The parametric Tukey HSD test was applied to MMS fa ll aerial-transect data (1982-2000) to compar e the distances of

bowhead whales north of a normalized coastline in two analysis regions of the Alaskan Beaufort

Sea from 140-156 ° W. longitude (see USDOI, MMS, 2003). While the Tukey HSD indicates significant differences between individual years, it does not compare actual levels of human activity in those years nor does it test for potential effects of sea ice and other oceanographic conditions on bowhead migrations (Treacy, 2000) . Treacy (2000) showed in a year-to-year comparison that the mean migration regionwide in fall 1998 was significantly closer to shore in both the East and West Regions than in 1999, a year with no offshore seismic or drilling activity during the fall season in th e Alaskan Beaufort Sea.

While other factors may have dom inating effects on site-specific distributions, such as prey concentrations, seismic activities, and localized vessel traffic, broad-ar ea fall distributions of bowhead whale sightings in the central Alaskan Beaufort Sea may be driven by overall sea-ice severity (Treacy, 2001). Treacy (2002) concluded that:

Bowhead whales occur farther offshore in heav y-ice years during fall migrations across the Central Alaskan Beaufort Sea (142° W to 155° W longitudes). Bowheads generally occupy nearshore waters in years of light sea-ice severity, somewhat more offshore waters in moderate ice years, and are even farther offshore in he avy ice years. While other factors...may have localized effects on site-specific distributions , broad-area distributions of bowhead whale sightings in the central Alaskan Beaufort S ea are related to overall sea-ice severity.

Further evidence that bowhead whales migrate at varying distances from shore in different years also is provided by site-specific studies monitori ng whale distribution relative to local seismic exploration in nearshore waters of the central Beaufort Sea (Miller et al., 1997; Miller, Elliot, and Richardson, 1998; Miller et al., 1999). In 1996, bowhead si ghtings were fairly broadly distributed between the 10-m and 50-m depth contours. In 1997, bowhead sightings were fairly broadly distributed between the 10-m and 40-m depth contours, unus ually close to shore. In 1998, the bowhead migration corrid or generally was farther offs hore than in either 1996 or 1997, between the 10-m and 100-m depth contours and approximately 10-60 km from shore.

15Aerial surveys near the proposed Liberty de velopment project in 1997 (BPXA, 1998) showed that the primary fall-migration route was offshor e of the barrier island s, outside the proposed development area. However, a few bowheads were observed in lagoon entrances between the barrier islands and in the lagoons immediately inside the barrier is lands, as shown in Figures 4-4 and 4-5 of the Environmental Report submitted by BPXA for the Liberty development project (BPXA, 1998). Because survey coverage in the nearshore area s was more intensive than in offshore areas, maps and tabulations of raw sigh tings overestimate the importance of nearshore areas relative to offshore areas. Transects ge nerally did not extend south of the middle of Stefansson Sound. Nevertheless, these data prov ide information on the presence of bowhead whales near the then-proposed Liberty devel opment area during the fall migration. Probably only a small number of bowheads, if any, came within 10 km (6 mi) of the area.

Some bowheads may swim inside the barrier is lands during the fall migration. For example Frank Long, Jr. reported that whales are seen inside the barrier is lands near Cross Island nearly every year and are sometimes seen between Seal Island and West Dock (U.S. Army Corps of Engineers, 1999). Crews from the commercial -whaling ships looked for the whales near the

barrier islands in the Beaufort Sea and in the lagoons inside th e barrier islands (Brower, 1980). Whales have been known to migrate south of Cross Island, Reindeer Island, and Argo Island during years when fall storms push ice against the barrier islands (Brower, 1980). Inupiat whaling crews from Nuiqsut also have noticed that the whale migration appears to be influenced by wind, with whales stopping when the winds ar e light and, when the wind starts blowing, the whales started moving through Captain Bay toward s Cross Island (Tuckle, as cited in USDOI, MMS, 1986). Some bowhead whales have been observed swimming about 25 yards from the beach shoreline near Point Barrow during the fall migration (Rexford, as cited in USDOI, MMS, 1996). A comment received from the Alaska Es kimo Whaling Commission on the Liberty draft EIS indicated that Inupiat work ers at Endicott have, on occasion, sighted bowheads on the north side of Tern Island. No specific information wa s provided regarding the location of the whale.

Data are limited on the bowhead fall migration th rough the Chukchi Sea before the whales move south into the Bering Sea. Bowhead whales co mmonly are seen from the coast to about 150 km (93 mi) offshore between Point Barrow and Icy Cape, suggesting that most bowheads disperse southwest after passing Point Barrow and cross th e central Chukchi Sea near Herald Shoal to the

northern coast of the Chukotka Peninsul a. However, sightings north of 72 ° N. latitude suggest that at least some whales migrate across the Chukchi Sea farther to the north. Mel’nikov, Zelensky, and Ainana (1997) argued that data su ggest that after rounding Point Barrow, some

bowheads head for the northwestern coast of the Chukotka Peninsula and others proceed primarily in the direction of the Bering Stra it and into the Bering Sea. Mel’nikov (in USDOC, NOAA, and NSB, 2005) reported that abundan ce increases along nor thern Chukotka in September as whales come from the north. Mo re whales are seen along the Chukotka coast in October. J.C. George (cited in IWC, 2004b) not ed that bowheads pass through the Bering Strait into the Bering Sea between October and Novemb er on their way to overwintering areas in the Bering Sea.

The timing, duration, and location of the fall migr ation along the Chukotka Peninsula are highly variable and are linked to the timing of freezeup (Mel’nikov, Zelensky, and Ainana, 1997).

16Whales migrate in “one short pulse over a mont h” in years with early freezeup, but when ice formation is late, whales migrate over a pe riod of 1.5-2 months in 2 pulses (Mel’nikov, Zelensky, and Ainana, 1997:13.

Feeding Bowheads are filter feeders, filtering prey from the water through baleen fibers in their mouth. They apparently feed throughout the water column, including bo ttomfeeding as well as surface skim feeding (Würsig et al., 1989). Skim f eeding can occur when animals are alone and conversely may occur in coordinated echelons of over a dozen animals (Würsig et al., 1989). Food items most commonly found in the stomachs of harvested bowheads include euphausiids, copepods, mysids, and amphipods. Euphausiids and copepods are thought to be their primary prey. Lowry, Sheffield, and George (2004) documented that other crustaceans and fish also were eaten but were minor components in samples consisting mostly of copepods or euphausiids.

Available data indicate that bowhead whales feed in both the Chukc hi and Beaufort Sea Planning Areas and that this use varies in degree among years, among individuals, and among areas. It is likely that bowh eads continue to feed opportunisti cally where food is available as they move through or about the Alaskan Beaufort Sea, similar to what they are thought to do during the spring migration. Observations fr om the 1980’s documented that some feeding occurs in the spring in the north eastern Chukchi Sea, but this f eeding was not consistently seen (e.g., Ljungblad et al., 1987; Carro ll et al., 1987). Stomach contents from bowheads harvested between St. Lawrence Island and Point Barrow during Ap ril into June also indicated it is likely that some whales feed during the spring migr ation (Carroll et al., 1987; Shelden and Rugh, 1995, 2002). Carroll et al. (1987) re ported that the region west of Point Barrow seems to be of particular importance for feeding, at least in so me years, but whales may feed opportunistically

at other locations in the lead system where oceanographic conditions produce locally abundant food. Lowry (1993) reported that the stomach s of 13 out of 36 spring-migrating bowheads

harvested near Point Barrow between 1979 thro ugh 1988 contained food. Lowry estimated total volumes of contents in stomachs ranged from less th an 1 to 60 liters (L), with an average of 12.2 L in eight specimens. Shelden and Rugh (1995) concluded that “In year s when oceanographic conditions are favorable, the lead system near Barrow may serve as an important feeding ground in the spring (Carroll et al., 1997).” Rich ardson and Thomson (2002) concluded that some, probably limited, feeding occurs in the spring.

It is known that bowhead whales feed in the Canadian Beaufort in the summer and early fall (e.g., Würsig et al, 1985), and in the Alaskan Be aufort in late summer/early fall (Lowry and Frost, 1984; Ljungblad et al., 1986; Schell a nd Saupe, 1993; Lowry, Sheffield, and George, 2004; summarized in Richardson and Thomson, 2002) . Available information indicates it is likely there is considerable inter-annual variabil ity in the locations where feeding occurs during the summer and fall in the Alaska Beaufort Sea, in the length of time i ndividuals spend feeding, and in the number of individuals feeding in various areas in the Beaufort Sea.

In at least some years, some bowheads apparently take their time returning westward during the fall migration, sometimes barely moving at all, w ith some localities being used as staging areas due to abundant food resources or social reasons (Akootchook, 1995, as reported in NMFS, 1).

17The Inupiat believe that whales follow th e ocean currents carrying food organisms (e.g., Napageak, 1996, as reported in NMFS, 2001). Bo wheads have been observed feeding not more than 1,500 feet (ft) offshore in about 15-20 ft of water (Rexford, 1979, as reported in NMFS, 2001). Nuiqsut Mayor Nukapigak testified at the Nuiqsut Public Hearing on March 19, 2001,

that he and others saw a hundred or so bowhead whales and gray whales feeding near Northstar Island (USDOI, MMS, 2002). Some bowheads appear to feed east of Barter Island as they migrate westward (Thomson and Richardson, 1987).

Interannual variability in the use of areas of the Beaufort Sea by bowheads for feeding also has been observed during aerial surveys by MMS and ot hers. Ljungblad et al. (1986) reported that feeding bowheads comprised approximately 25% of the total bowheads observed during aerial surveys conducted in the Beaufort Sea from 1979 through 1985. Miller, Elliott, and Richardson (1998) reported observing many aggr egations of feeding whales in nearshore waters near or just offshore of the 10-m depth contour during late summer/autumn 1997. In some years (e.g., 1997) (Miller, Elliot, and Richardson, 1998; Treacy, 2002) , many aggregations have been seen feeding (e.g., between Point Barrow and Smith Bay), wher eas in other years very little feeding was observed. Bowheads occasionally have been observed feeding north of Flaxman Island.

Based on stomach content data supplemented by beha vioral evidence, far more than 10% of the bowheads that passes through the eastern Alaskan Beaufort Sea during late summer and autumn

feed there. Based on examination of the stomach contents of whales harvested in the autumn between 1969-2000, Lowry, Sheffield, and George (2004) found that there were no significant difference in the percentages of bowheads that had been feeding between those harvested near Kaktovik (83%), Barrow (75%), or between subadu lts (78%) versus adults (73%). Twenty-four out of 32 whales taken during the fall at Kaktovik from 1979-2000 and included in this analysis were considered to have been feeding (Lowry and Sheffield, 2002).

Length-girth relationships show that subadult bowheads, and possi bly adults, gain weight while in the Beaufort Sea in summer and lose weight wh ile elsewhere. Lipid content of blubber, at least in subadults, is higher when they leave the Beaufort in fall than when they return in spring. This evidence suggests the importance of feeding in the Beaufort Sea during summer and early autumn. They do not show what fraction of the annual feeding occurs in the eastern and central Beaufort Sea. Lowry, Sheffield, a nd George (2004:221) concluded that:

... Bowhead whales feed regularly in the nearshor e waters of the eastern, central and western Alaskan Beaufort Sea during September and Oct ober...this entire region should be considered an integral part of the summer-autumn feeding range of bowhead whales. Results of stomach contents analysis, aerial obser vations, and traditional knowledge suggest that reference to the passage of bowhead whales through this regi on as a ‘westward autumn migration’ is misleading...it is a very incomplete description of their activities in the region. Second, feeding near Barrow during the spring migration is not just occasional, but rather a relatively common event...However, the amount of food in the st omachs tends to be lower in spring than in

autumn

....

However, examination of stomach contents only showed whether or not bowhead whales had fed and what prey were eaten, a nd it does not directly address the relative significan ce of feeding

18in various regions...This unresol ved issue remains important in the evaluation of possible cumulative effects of oil and gas development on bowhead whales

.....

Richardson and Thomson (2002) point ed out that bowhead activity throughout the year needs to be considered when evaluating the importance of feeding in the eastern Alaskan Beaufort Sea in late summer and autumn. Although numerous observations have been made of bowheads feeding during both the spring migr ation north to the Beaufort S ea and the fall migration west across the Alaskan Beaufort Sea, quantitative data showing how food consumed in the Alaskan

Beaufort Sea contributes to the bowhead whal e population’s overall annual energy needs is fairly limited. A study by Richardson (1987) concluded that food consumed in the eastern

Beaufort Sea contributed little to the bowhead whale population’s annual energy needs, although the area may be important to some individual whales. The study area for this 1985-1986 study extended from eastern Camden Bay to the Alaska /Canada border from shore to the 200-m depth contour for the intensive study area, and beyond this contour only for aerial survey data (Richardson and Thomson, 2002). The conclusion was controversial. The NSB’s Science Advisory Committee (1987) believed the study was too short in duration (two field seasons, one of which was limited by ice cover), suboptimal sa mpling designs, and difficulties in estimating food availability and consumption. The Committ ee did not accept the conclusion that the study area is unimportant as a feed ing area for bowhead whales.

Richardson and Thomson (2002) finalized th e report from the MMS -funded feeding study entitled Bowhead Whale Feeding in the Eastern Alas kan Beaufort Sea: Update of Scientific and Traditional Information, which compiled and in tegrated existing trad itional and scientific knowledge about the importance of the eastern Alaskan Beaufort Sea for feeding by bowhead whales. The project was an extension, with additional fieldwork (mainly in September of 1998, 1999, and 2000), of the previous study conducted in 1985 and 1986. The primary study area for this study extended the westward boundary about 1° longitude from that of the 1985-1986 study. Thus the boundary for the latter study was near the middle of Camden Bay (145° W. longitude).

With the concurrence of the NSB Scientific Revi ew Board, efforts in deep offshore areas were de-emphasized in this latter study so as to conc entrate efforts in shallo w areas of particular concern to Kaktovik hunters and, potentially, to oil industry. Boat-based zooplankton sampling

in 1998-2000 was limited to areas seaward of the 50- m contour. Aerial surveys extended to the 200-m contour, and MMS surveys extended further.

Baleen from bowhead whales provides a multiyear record of isotope ratios in prey species consumed during different seasons, including inform ation about the occurrenc e of feeding in the Bering Sea and Chukchi Sea system. The isotopic composition of the whale is compared with the isotope ratios of its prey from various ge ographic locations to make estimates of the importance of the habitat as a feeding area. Carbon-isotope analysis of bowhead baleen has indicated that a significant amount of feeding ma y occur in wintering areas (Schell, Saupe, and Haubenstock, 1987). Carbon-isotope analysis of zooplankton, bowhead tissues, and bowhead baleen indicates that a signifi cant amount of feeding may occur in areas west of the eastern Alaskan Beaufort Sea, at least by subadult whal es (Schell, Saupe, and Haubenstock, 1987).

19Recently, Lee at al. (2005) published data from is otope ratio analyses of bowhead baleen from whales all except one of whom had been harves ted in the autumn of 1997. Results of these samples were compared to data from baleen collected in past studies from both spring (predominantly) and autumn whales in 1986-1988 (s ee Table 1 in Lee et al., 2005:274). Lee et al. (2005:285) concluded that the new data con tinue to indicate that the “bowhead whale population acquires the bulk of its annual food intake from the Bering-Chukchi system.... Our data indicate that they acquire only a minority of thei r annual diet from the eastern and central Beaufort Sea...although subadult bowheads apparent ly feed there somewhat more often than do

adults. ”

Thomson, Koski, and Richardson (2002) concluded th at bowheads fed for an average of 47% of

their time in the eastern Alaskan Beaufort Sea during late summer and autumn. A substantial portion of the feeding occurred during travel. Am ong traveling whales, feeding as well as travel was occurring during a substa ntial percentage of the ti me, on the order of 43%.

The amount of feeding in the Chukchi Sea and Bering Strait in the fall is unknown, as is the amount of feeding in the Bering Sea in th e winter (Richardson and Thomson, 2002).

Vocalizations and hearing

Bowhead whales are believed to be most se nsitive to lower frequency sound. It may be reasonable that whales are most sensitive to noise at the frequencies at which they vocalize.

Most bowhead calls are at 50- 400 Hz, although components may reach as low as 35 Hz or as high as 5 kHz (Burns et al. 1993). Bowhead pr oduce various types of vocalizations, described as frequency modulated tonal ca lls in the 50-300 Hz range, comp lex calls which include pulsed sounds, squeals, growl-type sounds with abunda nt harmonic content, and call sequences. Bowhead vocalizations and hearing remain poorly understood, a lthough call duration, frequency, and type appear dependent on life hist ory, age, sex, behavior, time of year, and

outside stimuli such as industrial noise. No st udies have directly measured the sound sensitivity of bowhead whales. In a study of the morphology of the mysticete audito ry apparatus, Ketten (1997) hypothesized that large mysticet es have acute infrasonic hearing.

Bowhead whales are also known to sing during sp ring migrations. Source levels for bowhead calls have been estimated as high as 180-189 dB (Wursig and Clark, 1993). In addition to functioning with regard to communicating with others, bowheads may utilize vocalizations to maintain cohesion in migrations or to locate ice in order to migrate through the spring leads in

the Chukchi and Beaufort Seas.

Fin whale

ESA Listing History and Status The fin whale was listed as an endangered spec ies on June 2, 1970 (35 FR 8495). No critical habitat has been designat ed for the species.

Population and Stock Structure

20The fin whale is considered one of the more abundant large whale species, with a worldwide population estimate of 120,000. Three stocks are curre ntly recognized in U.S. waters: 1) Alaska (North Pacific), 2) California/Washington/Orego n, and 3) Hawaii. Prior to exploitation by whaling vessels, the North Pacific populati on consisted of an estimated 42,000 to 45,000 fin whales (Ohsumi and Wada 1974). Between 1914 and 1975, over 26,040 fin whales were harvested throughout the North Pacific (in Perry and others 1999). Annual catches in the North Pacific and Bering Sea range between 1,000 a nd 1,500 fin whales during the 1950's and 1960's. However, not all Soviet catches were reported. No reliable current popu lation estimate exists, but Angliss and Outlaw (2007) report a minimu m estimate of 5,700 for the North Pacific stock based on incomplete surveys over a portion of their range.

The distinctness of North Pacific and North Atla ntic fin whales has been supported by recent genetic analysis and by differences in vocaliza tions (NMFS 2006). At present, there are two named subspecies, B. p. physalus (Linnaeus 1758) in the North Atlantic and B. p

. quoyi (Fischer 1829) in the southern oceans. Most experts cons ider the North Pacific fin whales a separate unnamed subspecies. On a global scale, populations in the North Atlantic, North Pacific, and Southern Ocean probably mix rare ly (if at all), and there are geographica l populations within these ocean basins. Hatch (2004) reported differe nces in fin whale vocalizations between the North Atlantic and North Pacific, as well as regi onal differences within the North Atlantic. In addition there are morphological distinctions betw een these three groups. A dults in the Antarctic can be more than 23 m long and weigh more than 70,000 kg. In general, fin whales in the Northern Hemisphere attain a smaller maximum body length (by up to 3 m) than Antarctic fin whales, and those in the North Atlantic are leaner than their Antarctic counterparts (Lockyer and Waters 1986).

Reproduction, Survival and Non- Human Sources of Mortality The gestation period is probably somewhat less than a year, and fin whale calves are nursed for 6-7 months (NMFS 2006). The average calving interval has been estimated at about two years, based on whaling data. Natural sources and rates of mortal ity are largely unknow n, but Aguilar and Lockyer (1987) suggest annual natural morta lity rates may range between 0.04 and 0.06 (based on studies of northeast Atlantic fin whales).

Little is known about the natural causes of mort ality of fin whales. Ice entrapment is known to have injured or killed some fin whales in the North Atlantic, particular ly in the Gulf of St. Lawrence (NMFS 2006), and killer whales may attack fin whales, as has been reported for gray whales Disease presumably plays a major role in natural mortality as well, and shark attacks on weak or young individuals are pr obably common, but have not been documented. Lambertsen (in NMFS 2006) contended that cras sicaudiosis in the urinary trac t, was the primary cause of natural mortality in North Atlantic fin whales. Ra tes of natural mortality in fin whales generally are thought to range between 0.04 and 0.06.

Distribution and Habitat Use

The distribution of fin whales ca n be understood only in light of their feeding ecology (Mizroch et al. 2001). Fin whales are known to migrate between high la titude summer feeding grounds and lower-latitude wintering areas, although some individuals and even local populations do not.

21Rice (1974) reported that the summer distributi on of fin whales included immediate offshore waters throughout the North Pacific from central Ba ja California to Japan, and as far north as the Chukchi Sea. They occurred in high densities inthe northern Gulf of Alaska and southeastern Bering Sea from May to October, with some mo vement through the Aleutian passes into and out of the Bering Sea (NMFS 2006). Fin whales were observed and taken by Japanese and Soviet whalers off eastern Kamchatka and Cape Navarin, both north and south of the eastern Aleutians, and in the northern Bering and southern Chukc hi Seas (NMFS 2006). They were also taken by

whalers off central Californ ia throughout the year.

NMFS (2006) reports that fin whales have been observed year-round off central and southern California, with peak numbers in summer and fa ll, in summer off Oregon, and in summer and fall in the Gulf of Alaska (inc luding Shelikof Strait), and the southeastern Bering Sea. Their regular summer occurrence has also been noted in recent years around the Pribilof Islands in the northern Bering Sea. Data suggest that, as in th e North Atlantic, the migr atory behavior of fin whales in the eastern North Pacific is comple x: whales can occur in any one season at many different latitudes, perhaps depending on their ag e or reproductive state as well as their stock affinity. Movements can be either inshore/offs hore or north/south. Some individuals remain at high latitudes through the winter. Fin whale concen trations in the northern North Pacific and Bering Sea generally form along frontal boundari es, or mixing zones between coastal and oceanic waters, which themselves correspond ro ughly to the 200-m isobath (shelf edge) (NMFS 2006).

Fin whales may occur seasonally in the southweste rn Chukchi Sea, north of the Bering Strait along the coast of the Russian C hukotka (also referenced as th e Chukchi) Peninsula. Their known current summer feeding habitat incl udes the southern por tion, especially the southwestern portion, of the Chukchi Sea along the Asian coast. This species’ current use of parts of its historic range probably is modified due to serious population reduction during commercial hunting. However, there is no indicati on that fin whales typically occur within the

Chukchi Sea or Beaufort Sea Planni ng Areas or in areas directly adjacent. There have been only

rare observations of fin whales into the eastern half of the Chukchi Sea. In the southeast Chukchi Sea on September 23, 2006, three adult fin whales were seen from a vessel by marine mammal observers (Patterson, et al., 2007). In 1981, three fin whales (two adults, one calf) were observed (Ljungblad, et al., 1982) in the extr eme southern Chukchi Sea associated with the aerial surveys of endangered whales in the Beaufo rt Sea, Chukchi Sea, and northern Bering Sea. These represent the only conf irmed observations since 1979 in or near the planning areas (neither of these occurrences o ccurred within the pla nning areas). No other sightings of fin whales were reported during aerial surveys of e ndangered whales in summer (July) and autumn (August, September, and October) of 1979-1987 in the northern Bering Sea (from north of St. Lawrence Island), the Chukchi Sea nor th of lat. 66o N. and east of the International Date Line, and the Alaskan Beaufort Sea from long. 157o01’ W. east to long. 140o W. and offshore to lat. 72o N. (Ljungblad et al., 1988). Fin whales have not been observ ed during annual aerial surveys of the Beaufort Sea conducted in Septem ber and October from 1982-2007 (e.g., Monnett and Treacy, 2005; Moore et al., 2000; Treacy, 2002; Monnett, 2008, pers. commun.). During a

research cruise in the Chukchi and Beaufort seas (from July 5-August 18, 2003), in which all marine mammals observed were recorded, no fin whales were observed (Bengtson and Cameron, 2003).

22Thus, for the purposes of our analyses, we assume that:

• Fin whales are uncommon to the eastern Chukchi Sea and the Chukchi OCS Planning

Area in which lease sales are held.

• Fin whales do occur south and west of th e Chukchi Sea Planning Areas, and may expand

northward in the future. Continued arctic warming could result in change s in oceanographic condit ions favorable to the

distribution and abundance of fin whale prey species, and the ex tended distribution into waters of the Chukchi and possibly Beaufort Sea.

Feeding Fin whales feed primarily on euphausiids, or “kri ll”, but also consume su bstantial quantities of fish. In the North Pacific overall, fin wh ales apparently prefer euphausiids (mainly Euphausia pacifica

, Thysanoessa longipes

, T. spinifera , and T. inermis ) and large copepods (mainly

Calanus cristatus ), followed by schooling fish such as herring, walleye pollock ( Theragra chalcogramma ), and capelin (Nemoto 1970; Kawamura 1982). Fin whales killed off central California in the early twentieth century were de scribed as having either plankton (assumed to have been mainly or entirely euphausiids) or sardines (assumed to have been anchovies, Engraulis mordax ) in their stomachs (Clapham et al. 1997). A larger sample of fin whales taken

off California in the 1950s and 1960s were feeding mainly on krill ( Euphausia pacifica ), with only about 10% of the individuals ha ving anchovies in their stomachs.

Mizroch et al. 2001 report Thyanoessa raschii is the only species of euphausiid taken by fin whales In the northern Bering Sea, while fishes consumed by fin whales in Arctic and Subarctic waters are mainly capelin, Alaska Pollock, herrin g, and saffron cod. Fish is the main food for fin whales north of 58 degreees in the Bering Sea, and consists mainly of capelin, Pollock, and herring.

Foraging areas tend to occur along continental shelves with productive upwellings or thermal

fronts. Fin whales tend to avoi d tropical and pack ice waters (NMFS 2006) with the northern limit set by ice and the southern limit by wa rm water of approximately 15°C (60°F.

Vocalizations and hearing

Underwater sounds of the fin whale ar e one of the most studied of the Balaenopteras . Fin whales produce a variety of low-frequency sounds in the 10 to 200 Hz band (NMFS 2005). The most typical signals are long, pa tterned sequences of short duration (0.5 to 2 seconds) infrasonic pulses in the 18 to 35 Hz range (Patterson and Hamilton 1964). Estimated source levels are as high as 190 dB re 1 μ Pa (McDonald and others 1995a; Patterson and Hamilton 1964; Thompson and others 1992; Watkins and others 1987), but Ch arif and others (2002) estimated source levels

at 159 to 184 dB re 1 μ Pa after correcting for the Lloyd Mi rror effect. In temperate waters intense bouts of long patterned s ounds are very common from fall through spring, but also occur to a lesser extent during the su mmer in high latitude feeding areas (Clark and Charif 1998). Short sequences of rapid pulses in the 20 to 70 Hz band are associated with animals in social groups (McDonald and others 1995a). Each pulse lasts on the order of one second and contains twenty cycles (Tyack 1999).

23Particularly in the breeding season, fin whales pr oduce series of pulses in a regularly repeating pattern. These bouts of pulsing may last for longe r than one day (Tyack 1999). The seasonality and stereotype of the bouts of patterned sounds suggest that these sounds are male reproductive displays (Watkins and others 1987), while the in dividual counter-calling da ta of McDonald and others (1995a) suggest that the more variable calls are contact calls. As with other mysticete sounds, the function of vocalizations produced by fin whales is unknown. As with blue whales, the low-frequency sounds produced by fin whales have the potential to travel over long distances, and it is possible th at long-distance co mmunication occurs (Edds-Walton 1997; Payne and Webb 1971).

No studies have directly measured the sound sensitivity of fin whales. In a study of the morphology of the mysticete auditory appara tus, Ketten (1997) hypot hesized that large mysticetes have acute infrasonic hearing.

Humpback Whale

ESA Listing History and Current Status The humpback whale was listed as an endangere d species on June 2, 1970 (35 FR 8495). No critical habitat has been designated for the species.

Distribution Humpback whales are found primarily in coastal and continental shelf wa ters, but are known to migrate through deep waters betw een tropical/sub-tropical breedi ng and calving habitats during the winter and temperate/polar feeding habitats during the summer. Known breeding areas in the Pacific Ocean include Japan, th e Hawaiian Islands, coastal Central America and Mexico, and Revillagigedo Archipelago. Humpback whales summer throughout the central and western portions of the Gulf of Alaska, includi ng Prince William Sound, around Kodiak Island (including Shelikof Strait and the Barren Islands), and along the southern coastline of the Alaska Peninsula, as well as the coast of California. It is believed that minimal feeding occurs in wintering grounds (Salden 1987).

NMFS (1991a) (citing Nikulin, 1946 and Berzin and Rovnin, both in Russian), summarized that the northern Bering Sea, Bering Strait, and southern Chukchi Sea along the Chukchi Peninsula are the northern extreme of the range of the humpback. Figure 38 of the most recent (Angliss and Outlaw, 2008) stock assessment for the Western North Pacific Stoc k (WNPS) depicts the southwestern Chukchi Sea as part of the “approxi mate distribution” of humpback whales in the

North Pacific. Other references indicate that both the histori cal and current summer feeding habitat of the humpback include d, and at least sometimes in cludes, the southern portion, especially the southwestern por tion, of the Chukchi Sea. Mizr och et al. (In prep.) cited Zenkovich, a Russian biologist who wrote that in the 1930’s (quote in Mizroch et al., In prep.): “The Polar Sea, in areas near Cape Dezhne v...is frequented by large schools (literally hundreds...) of fin whales, humpbacks, a nd grays.” Mel’nikov (2000) wrote:

In the fall, humpback whales formed aggreg ations in the most southern part of the Chukchi Sea, in the Senyavin Strait, and in th e northern part of the Gulf of Anadyr. The

24whales left the area of the survey prior to th e start of ice formation. Both in the past and at present, these waters are the summer feeding ground of humpback whales. The regular character of the encounters with th e humpback whales points to signs of the

restoration in their numbers in th e waters off Chukchi Peninsula.

Until 2007, historic and recent information did not indicate humpback whales inhabit northern portions of the Chukchi Sea or enter the Beaufort Sea. No sightings of humpback whales were reported during aerial surveys of endangered whal es in summer (July) and autumn (August, September, and October) of 1979-1987 in the Nort hern Bering Sea (from north of St. Lawrence Island), the Chukchi Sea north of lat. 66o N. and east of the In ternational Date Line, and the Alaskan Beaufort Sea from long. 157o01’ W. east to long. 140o W. and offshore to lat. 72o N. (Ljungblad et al., 1988). They have not been observed during annual aerial surveys of the Beaufort Sea conducted in September and Oc tober from 1982-2007 (e.g., Monnett and Treacy, 2005; Moore et al., 2000; Treacy, 2002; Monnett, 2008, pers. commun.). During a 2003

research cruise in which all ma rine mammals observed were reco rded from July 5 to August 18 in the Chukchi and Beaufort seas, no humpback whales were observed (Bengtson and Cameron, 2003). One observation of one humpback wh ale was recorded in 2006 by marine mammal

observers aboard a vessel in the southern Chukc hi Sea outside of the Chukchi Sea Planning Area (Patterson et al., 2007; unpublished MMS mari ne mammal-observer reports, 2006). During summer 2007 between August 1 and October 16, hum pback whales were observed during seven observation sequence events in the western Alaska Beaufort Sea (1) and eastern and southeastern Chukchi Sea (6) (unpublished MM S marine mammal-observer reports, 2007) and

one other observation in the southern Chukc hi Sea in 2007 (Sekiguchi, In prep.).

Thus, for the purposes of our analyses, we assume that:

• Humpback whales recently have been obser ved in the western Alaskan Beaufort Sea (2007) and southern and eastern Chukchi Sea (2006, 2007). We assume these areas are a portion of the potentially expanding summer distribution or summer feeding grounds for this species.

• We assume that the humpback whales recently encountered in the Chukchi and Beaufort seas most likely would be long to the WNPS, but indivi dual photo-identification and genetic data are needed to confirm stock origin.

• We assume it is unlikely that humpback wh ales from the Central North Pacific Stock (CNPS) would be present in the norther nmost Bering Sea near Bering Strait or seasonally be present within the southwester n, southeastern, or eastern Chukchi Sea or

the western Beaufort Sea.

• Humpback whales do not tend to occur fart her north but can and do occur within the

Chukchi Sea and western Beaufort Sea Planni ng Areas, and may continue to do so in the

future.

• Continued arctic warming could result in ch anges in oceanographic conditions favorable to the distribution and abundance of humpb ack whale prey species, and the seasonal distribution and movements of humpback whales.

Observations by Mel’nikov (2000) of humpback whales adjacent to the Chukotka Peninsula indicate that humpbacks whales are present and feeding in the most northerly portions of the northwestern Bering Sea in the summer and autumn prior to ice formation. Thus, for purposes

25of analyses, we assume that humpbacks do occur seasonally just south of the Bering Strait and

that these whales are the source of those observe d in the U. S. Beaufort and Chukchi Seas in 2006-2007 and likely to be of the WNPS. In 2007 hu mpbacks did occur in the western Beaufort Sea (one documented sighting sequence) and, in 2006 and 2007, were observed in the southern and eastern Chukchi Sea (seven documented si ghting sequences); they transit between the Chukchi and Bering seas through the Be ring Strait in summer and autumn.

Population status and trends Three management units (populations) of humpb ack whales currently ar e recognized in the North Pacific. The following units migrate be tween their respective summer/fall feeding areas to winter/spring calving and mati ng areas in the North Pacific (Calambokidis et al. 1997, Baker et al. 1998):

1) the California/Oregon/Washington and Mexico population, which are found winter/spring in coastal Central America and Mexico and migrate to the coast of

California to southern British Columbia in summer/fall (Calambokidis et al. 1989, Steiger et al. 1991, Ca lambokidis et al. 1993);

2) the Central North Pacific population, which are found winter/spring in the Hawaiian Islands and migrate to norther n British Columbia/southeast Alaska (including Glacier Bay) and Prince Willia m Sound west to Kodiak in summer/fall (Baker et al. 1990, Perry et al. 1990, Calambokidis et al. 1997); and

3) the Western North Pacific population, wh ich occurs in winter/spring off Japan and, based on Discovery Tag information, pr obably migrate to waters west of the Kodiak Archipelago (the Be ring Sea and Aleutian Islands) in summer/fall (Berzin and Rovnin 1966, Nishiwaki 1966, Darling 1991).

For the purposes of this Opinion, the effects of the proposed action on humpback whales will be assessed for two of these three management un its based on the known and suspected ranges of these populations, which would place only the Ce ntral North Pacific popu lation and the Western North Pacific population within this area.

Western North Pacific Population

The continental shelf of the Aleutian Islands and Alaska Peninsula were once considered the center of the North Pacific humpback whale population (Berzin and Rovnin 1966; Nishiwaki 1966). The northern Bering Sea, Bering Strait, a nd the southern Chukchi Sea along the Chukchi Peninsula appear to form the northern extreme of the Western North Pacific population’s range (Nikulin 1946, Berzin and Rovnin 1966). However, sightings of humpback whales in the Bering Sea were most frequent south of Nunivak Island and east of the Pribilof Islands (Berzin and Rovnin 1966; Braham et al. 1977; Nemoto 1978; Braham et al. 1982; Leatherwood et al . 1983).

Surveys in the central-eastern and southeastern Bering Sea in 1999 and 2000 resulted in new

information about the distribution of humpback whales in these areas (Moore et al. 2002). The only sightings of humpback whal es in the central-eastern Beri ng Sea were southwest of St.

26Lawrence Island; animals co-occurred with a group of killer whales and a large aggregation of Arctic cod. A few sightings occu rred in the southeast Bering S ea, primarily outside Bristol Bay and north of the eastern Aleutian Islands (Moore et al. 2002). In a NMFS survey cruise in 2001

and 2002 of the central and eastern Aleutian Is lands, humpback whales were most common in the area between Samalga and Unimak Islands (S inclair et al. 2005). Of the 259 individuals seen, only 3 were west of Samalga. These recen t sightings clearly demonstrate that the Aleutian Islands and Bering Sea remain important feed ing areas (NMFS 2006a). In addition, a NOAA survey conducted in 2005 found numerous humpb ack whales north of the central Aleutian Islands, reinforcing the idea that the Bering Sea is an important foraging habitat (Angliss and Outlaw 2008).

New information from a variety of sources indi cates that humpback whales from the western

and central North Pacific stocks mix on summer f eeding grounds in the ce ntral Gulf of Alaska and perhaps the Bering Sea. A major research e ffort, SPLASH (Structure of Populations, Levels of Abundance and Status of Humpb ack Whale Stocks), was initiated in 2002 in order to better

delineate stock structure of hum pback whales in the North Pacifi c using a variety of techniques, and it is expected that this effort will assist in resolving stock structure in the near future (Angliss and Outlaw 2008).

Central North Pacific Population Humpback whales in the Cent ral North Pacific population su mmer throughout southeast Alaska, the central and western portions of the GOA, including Prince W illiam Sound, around Kodiak Island (including Shelikof Strait and the Barren Islands), and along the southern coastline of the Alaska Peninsula. In Prince William Sound, duri ng recent years [i.e., prior to 1991], humpback whales have congregated near Naked Islands, in Perry Passage, near Chenega Island, in Jackpot, Icy and Whale Bays, in Port Bainbridge and nor th of Montague Islands between Green Island and the Needle (Hall 1979, 1982; von Ziegesar 1 984; von Ziegesar and Matkin 1986). The few sightings of humpback whales in offshore waters of the central GOA are usually attributed to animals migrating into coastal waters (Morri s et al. 1983), although use of offshore banks for feeding is also suggested.

Humpback whales of the Central North Pacific population spend the winter months in the waters off Hawaii where they breed, give birth to and nurse their calv es. The whales undertake the northward migration to Alaska wa ters in late winter and genera lly arrive on the feeding grounds in May, remaining into November before returni ng to the waters off Hawaii. Some animals, however, remain on the feeding grounds year-r ound. Humpback whales do not feed while on the wintering grounds off Hawaii.

Impacts of human activities Humpback whale populations were severely depleted from commer cial whaling (see Forney and others 2000). With the prohibition on whaling, inci dental entanglements in fisheries gear and ship strikes are the primary th reats to humpback whales. A ngliss and Outlaw (2008) report 54 incidents of human-related mortalities between 2001 and 2005, of which 40 involved commercial fishing gear. On the Pacific coast, a humpback whale is killed about every other year by ship strikes (Barlow et al. 997). On the Atlantic coast, six out of 20 humpback whales stranded along the mid- Atlantic coast showed signs of major ship strike injuries (Wiley et al.

271995). Almost no information is av ailable on the number of humpback whales killed or injured by entanglement in fishing gear or ship strikes outside of U.S. waters.

Life history Humpback whale reproductive activities occur prim arily in winter. The ag e distribution of the humpback whale population is unknown, but the propor tion of calves in va rious populations has been estimated at 4 to 12% (Bauer 19 86; Clapham and Mayo 1987; Whitehead 1982). Humpback whales exhibit a wide range of foragi ng behaviors, and feed on a range of prey types including small schooling fishes, euphausiids, a nd other large zooplankton. Fish prey in the North Pacific include herring, an chovy, capelin, pollock, Atka mackerel, eulachon, sand lance, pollock, Pacific cod, saffron cod, arctic cod, juve nile salmon, and rockfish. Invertebrate prey include euphausiids, mysids, amphipods, shrimps, and copepods.

Diving and social behavior Maximum diving depths for humpbacks are approxi mately 150 m (492 ft) (but usually <60 m or 197 ft), with a very deep dive (240 m or 787 ft) recorded off Bermuda (Hamilton and others 1997). They may remain submerged for up to 21 min (Dolphin 1987). In southeast Alaska average dive times were 2.8 min for feeding whales, 3.0 min for non-feeding whales, and 4.3 min for resting whales (Dolphin 1987). In the Gu lf of California humpback whale dive times averaged 3.5 min (Strong 1990). Because most humpback prey is likely found in waters shallower than 300 m most humpback dives are probably relatively sh allow. Clapham (1996) reviewed the social behavior of humpback whal es. They form small unstable groups during the breeding season. During the feeding season they fo rm small groups that occasionally aggregate on concentrations of food. Feeding groups are some times stable for long periods of times. There is good evidence of some territoriality on feeding grounds (Clapham 1994; 1996), and on wintering grounds (Tyack 1981). On the breedi ng grounds males sing long complex songs directed towards females, other males or both.

Vocalizations and hearing Humpbacks produce a wide variety of sounds . During the breeding season males sing long, complex songs, with frequencies in the 25 to 5000 Hz range and intensit ies as high as 181 dB (Payne 1970; Thompson et al 1986). Source levels average 155 dB and range from 144 to 174 dB (Thompson et al. 1979). The songs appear to have an effective range of approximately 10 to 20 km (six to 12 mi). Animals in mating groups produce a variety of sounds (Silber 1986; Tyack 1981; Tyack and Whitehead 1983). Sounds are produced less frequently on the summer feeding grounds. Feeding groups produce dis tinctive sounds ranging from 20 Hz to 2 kHz, with median

durations of 0.2 to 0.8 sec and source levels of 175 to 192 dB (Thompson and others 1986). No studies have directly measured the sound sens itivity of humpback whales. In a study of the morphology of the mysticete auditory appara tus, Ketten (1997) hypot hesized that large mysticetes have acute infrasonic hearing.

III. ENVIRONMENTAL BASELINE For the purposes of interagency consultations un der Section 7 of the ESA, the environmental baseline is defined to include the past and present impacts of all Federal, State, or private actions and other human activities in an action area, the anticipated impacts of all proposed Federal

28projects in an action area that have already undergone formal or early Section 7 consultation, and the impact of State or private actions that are contemporaneous with the consultation in process [50 CFR §402.02].

The following factors, other than the proposed acti on, have had or are having potential effects on

all or some of these enda ngered species of whales:

historic commercial whaling; subsistence hunting; oil- and gas-related activity; non-oil and gas industrial development w ithin the range of these whales; research activities; marine vessel-traffic and commercial-fishing; pollution and contaminants baseline; and climate change.

There are no data available that indicate that , other than historic commercial whaling, any previous human activity has had a significant population-level advers e impact on the current status of fin whales, the West ern Arctic stock of bowheads, the Central North Pacific and

Western North Pacific stocks of humpback whales, or the recovery of any of these species. Currently available information indicates that at the population level, bowheads using the

Beaufort and Chukchi Sea Planni ng Areas are resilient at least to the level of human-caused mortality and disturbance that currently exists within their range, and has existed since the cessation of commercial whaling. Although da ta on such impacts to humpback and fin populations in the Beaufort and Chukchi Sea Planning Areas are curre ntly lacking, it is reasonable to assume that effects may be similar and that these species are also resilient to the current level of human-caused mortality and distur bance in these areas. Given that these whales have not previously been detected in the action ar ea, it is likely that only a small portion of the population is using this habitat a nd thus impacts would not rise to a population level effect.

Data indicate that at least some bowheads are extremely long-lived (100+ years or more). Thus, many of the individuals in this population may al ready have been exposed to a high number of

disturbance events in their lifetimes. Th e primary known current human-related cause of mortality is a regulated subsiste nce hunt by Alaska Natives, which occurs at different times of the year in many of the coastal por tions of their range. No subsiste nce hunt occurs on either fin whales or humpback whales.

The existence of the bowhead hunt has focused Nativ e, local, state, federal, international, and industry research and monitoring attention on th is stock and the development of mitigations intended to ensure its continued availability for s ubsistence take adequate to meet the needs of bowhead-hunting Native communities. Since the level of take is directly linked to the population abundance and status of this population, protection of the availability of whales for subsistence take is linked to protection needed to ensure the long-term viability of the population. Whether there are long- lasting behavioral effects from this activity is unknown, but overall habitat use appears to be relatively unaffected.

Historical Commercial Whaling

29It is clear that commercial whaling between 1848 and 1915 was th e human activity that had the greatest adverse effect on the bowhead whale population. Woody and Bo tkin (1993) estimated

that the historic abundance of bowheads in this population was between 10,400 and 23,000 whales in 1848, before the advent of commerc ial whaling. Woody and Botkin (1993) estimated between 1,000 and 3,000 animals remained in 1914, near the end of the commercial-whaling period. Commercial whaling also may have cau sed the extinction of some subpopulations and some temporary changes in distribution. Follo wing protection from whaling, this population (but not some other bowhead populations) has sh own marked progress toward recovery. As

noted in the affected environment secti on, bowhead population estimates for 2001 range between 10,470 (SE = 1,351) with a 95% confid ence interval of 8,100–13,500 (George et al., 2004) and 10,545 CV(N) =0,128 (Zeh and Punt, 2004, cited in Angliss and Outlaw, 2005. Thus estimated bowhead population size is within th e lower bounds of estimates of the historic population size. Recently, Shelden et al. (2001, 2 003) concluded that this population should be removed from the list of species desi gnated as endangered under the ESA.

Significant commercial whali ng harvest also reduced the size of the humpback whale population. At the time of its listing as endangered under th e ESA in 1973, the population was considered to be in danger of extinction in all or a portion of its range. Historically, both aboriginal and early commercia l harpoon whalers harvested anunknown number of humpback whales. Much greater harvest pressure occurred in the 20 th century when these animals were subject to heavy commercial exploitation during modern wha ling operations. Prior to 1905, there were an estimated 15,000 humpback whales in the entire North Pacific; by 1966, following commercial harvest, the population was estimat ed to be between 1,000 and 1,200 animals. Measures to protect the humpback whales in the North Atlantic were first taken in 1946 with the establishment of the regulatory Interna tional Whaling Commission (IWC), and a ban on nonsubsistence hunting followed in 1955. In 1965, the IWC banned the commercial hunting of humpback whales in the Pacific Ocean

. Soviet whalers, however, continued to harvest humpback whales until 1980 (Perry et al.1999). Currently, some illegal whaling continues although actual harvest levels are unknown.

Fin whales were hunted occasionally by the saili ng-vessel whalers of the 19th century (e.g., see Scammon 1874; Mitchell and Reeves 1983). The in troduction of steam powe r in the second half of that century made it possible for boats to overtake the large, fast-swimming rorquals, including fin whales, and the use of harpoon-gun technology resulted in a high loss rate (Schmitt et al. 1980; Reeves and Barto 1985). The eventual introduction of deck-mounted harpoon cannons made it possible to kill and secure blue , fin, and sei whales on an industrial scale (Tønnessen and Johnsen 1982). Fin whales were hunt ed, often intensively, in all the world's oceans for the first three-quarters of the twentieth century. The total reported catch of fin whales in the Southern Hemisphere from 1904 through 1979 was close to three-quarters of a million, making them numerically dominant, by far, among the commercially expl oited baleen whales (see IWC 1995:129 B 30).

Under the 1946 International Convention for the Regulation of Whaling, a minimum size limit of 55 ft (16.8 m) was in effect for fin whales taken by commercial whaling in the North Pacific, and two fin whales were calculated as equivalent to one A blue whale unit @ under the initial production quota scheme (Allen 1980). The Intern ational Whaling Comm ission (IWC) did not begin managing commercial whaling for fin whal es on a species basis until 1969 in the North Pacific (Allen 1980) and 1976 in the North Atla ntic (Sigurjónsson 1988). The fin whale was given full protection from co mmercial whaling in the Anta rctic beginning in the 1976/77 whaling season, the North Pacific in the 1976 seas on, and the North Atlantic in the 1987 season.

30Since 1987, the only area in th e Northern Hemisphere where fin whales have been hunted legally is Greenland. There, a take of about 20 fi n whales per year has been authorized under the
IWC

= s aboriginal subsistence whaling sc heme (Gambell 1993; Caulfield 1993).

Subsistence Hunting Indigenous peoples of the arctic and subarctic of what is now Alaska have been hunting bowhead whales for at least 2,000 years (Stoke r and Krupnik, 1993). Thus, subsistence hunting

is not a new contributor to cu mulative effects on this population. There is no indication that, prior to commercial whaling, subsistence wha ling caused significant adverse effects at the population level. However, modern technology ha s changed the potential for any lethal hunting of this whale to cause population- level adverse effects if unregulat ed. Under the authority of the IWC, the subsistence take from this population has been regula ted by a quota system since 1977. Federal authority for cooperative management of the Eskimo subsistence hunt is shared with the Alaska Eskimo Whaling Commission (AEWC) through a cooperative agreement between the AEWC and the United States Department of Commerce, National Oceanic and Atmospheric Administration (NOAA).

The sustainable take of bowhead whales by in digenous hunters represen ts the largest known human-related cause of mortality in this population at the present time. Available information suggests that it is likely to remain so for the foreseeable future. While other potential effectors primarily have the potential to cause , or to be related to, behavior al or sublethal adverse effects to this population, or to cause the deaths of a small number of individuals, little or no evidence

exists of other common human-related causes of mo rtality. Subsistence ta ke, which all available evidence indicates is sustainable, monitored, managed, and regulated, helps to determine the resilience of the population to other impacts that could potentially cause lethal takes. Currently, Alaskan Native hunters from 10 villages harvest bowheads for subsistence and cultural purposes under a quota authorized by the IW C. Chukotkan Native whalers from Russia

also are authorized to harvest bowhead whales un der the same authorized quota. The status of the population is closely monitore d, and these activities are closel y regulated. Strike limits are established by the IWC and set at a 5-year quota of 280 landings. The sustained growth of the Western Arctic bowhead population indicates thatthe level of subsistence take has been sustainable. Because the quota for the hunt is tied to the population size and population parameters, it is unlikely this source of mortality will contribute to a significant adverse effect on the recovery and long-term viability of this population.

There are adverse impacts of the hunting to bowhead whales in addition to the death of animals that are successfully hunted and th e serious injury of animals that are struck but not immediately

killed. Available evidence indicates that subs istence hunting causes dist urbance to the other whales, changes in their behavior, and sometimes temporary effects on habitat use, including migration paths. Modern subsistence hunting repr esents a source of noise and disturbance to the whales. Whales in the vicinity of a struck whale could be disturbed by the sound of the explosive used in the hunt, th e boat motors, and any sounds made by the injured whale. NMFS (2003a) pointed out that whales that are not struck or kill ed may be disturbed by noise associated with the approaching hunters, their vessels, and the sound of bombs detonating:

“...the sound of one or more bombs detonations dur ing a strike is audible for some distance. Acousticians, listening to bowhead whale calls as part of the cen sus, report that calling rates drop after such a strike ...” (NMFS, 2003). We are not aware of data indicating how far

31hunting-related sounds (for example, the sounds of vessels and/or bombs) can propagate in areas where hunting typically occurs, but th is is likely to vary with envi ronmental conditions. It is not

known if whales issue an “alarm call” or a “distress call” after they, or another whale, are struck.

NMFS (2003) reported that: ...whales may act skittish” and wary after a bom b detonates, or may be displaced further offshore (E. Brower, pers. com.). However, disturba nces to migration as a result of a strike are temporary (J. George, 1996), as evidenced when several whales may be landed at Barrow in a single day. There is some potential that migrati ng whales, particularly calves, could be forced

into thicker offshore ice as th ey avoid these noise sources. The experience of Native hunters suggests that the whales would be more likely to temporarily halt th eir migrations, turn 180 degrees away...(i.e., move back th rough the lead systems), or become highly sensitized as they continue moving (E. Brower, pers. com .).

Because evidence indicates that bowhead whales are long-lived, some bowhead whales may have been in the vicinity where hunting wa s occurring on multiple, perhaps dozens or more, occasions. Thus, some whales may have cumulativ e exposure to hunting activities. This form

of noise and disturbance adds to noise and disturbance from othe r sources, such as shipping and oil and gas-related activities. To the extent such activities occur in the same habitats during the period of whale migration, even if the activities (e.g., hunting a nd shipping) themselves do not occur simultaneously, cumulative effects from all noise and disturbance could affect whale habitat use. However, we are not aware of information indica ting long-term habitat avoidance has occurred with present levels of activity. Additionall y, if whales become more “skittish” and more highly sensitized following a hunt, it may be that their subsequent reactions, over the short-term, to other forms of noise and disturbance are heightened by such activity. Data are not available that permit evaluation of this possible, speculative interaction.

There is currently no subsistence hunt for humpback whales or fin whales in U.S. waters. Fin whales, however, are presently hunted legally in the Northern Hemisphere in Greenland under the IWC’s procedure for abor iginal subsistence whaling.

Commercial-Fishing, Marine Vessel-Tra ffic, and Research Activities

Bowhead Whales Based on available data, previous incidental take of bowhead whales apparently has occurred only rarely. The bowhead’s association with s ea ice limits the amount of fisheries activity occurring in bowhead habitat. However, the freq uency of such interactions in the future would be expected to increase if co mmercial-fishing activities expand northward. There is some uncertainty about whether such expansion will o ccur. Increases in spatial overlap alone could

result in increased interactions between bowhead s and derelict fishing gear. In a discussion of population climate warming impacts on bowhead s at the meeting of the Subcommittee on Bowheads, Right Whales and Gray Whales at th e IWC’s annual meeting, P. Wade (referred to in IWC, 2005b) reported that that th e commercial crab fishery exte nded further north the previous winter (winter 2004-2005) than in previous years.

Between 1989 and 1994, logbook data on incidental ta ke of bowheads are available, but after that time, the requirement is for fishers to self report. Angliss and L odge (2002) reported that

32“the records are considered incomplete and es timates of mortality based on them represent

minimums .” There are no observer program records of bowhead whale mortality incidental to commercial fisheries in Alaska (Angliss and Lo dge, 2002). New information on entanglements

of bowhead whales indicates that bowheads do have interactions with crab- pot gear. There have

been two confirmed occurrences of entanglement in crab-pot gear, one in 1993 and one in 1999 (Angliss and Lodge, 2008). Table 41 in Angliss a nd Lodge (2008) details reports of scarring of bowhead whales attributed to entanglement in ropes. Citing a personal communication from Craig George of the NSB, Department of W ildlife Management, Angliss and Lodge (2008 report a preliminary result from reexamination of bowh ead harvest records suggest that there may be more than 20 cases indicating entanglements or scarring attributable to ropes in the bowhead harvest records. Angliss and Lodge (2008) reported that the annua l rate of bowhead entanglement in marine debris /gear for the period 2003-2008 is 0.4.

Potential effects on bowhead whales from commerci al-fishing activities include incidental take in the fisheries and/or entanglement in derelict fishing gear resulting in death, injury, or effects

on the behavior of individual whal es; disturbance resulting in tem porary avoidance of areas; and whales being struck and injured or killed by ve ssels. Bowheads have been entangled in ropes from crab pots, harpoon lines, or fishing nets ; however, the frequency of occurrence is not

known.

Marine vessel traffic, in general, can pose a th reat to bowheads because of the risk of ship strikes. Shipping and vessel traffi c is expected to increase in th e arctic if warming continues. Additionally, noise associated wi th ships or other boats potenti ally could cause bowheads to alter their movement patterns or make other chan ges in habitat use. Pollution from marine vessel traffic, especially from large vessels su ch as large cruise ships, also could cause degradation of the marine environment and in crease the risk of the whales’ exposure to contaminants and disease vectors. The frequenc y of observations of vessel-inflicted injuries suggests that the incidence of ship collisions with bowhead whales is low but may be increasing. Between 1976 and 1992, only three ship -strike injuries were docum ented out of a total of 236

bowhead whales examined from the Alaskan subs istence harvest (George et al. 1994). The low

number of observations of sh ip-strike injuries suggests that bowheads either do not often encounter vessels, or they avoid interactions with vessels, or that interactions usually result in

the animals’ death.

Increased use of vessels for ice management asso ciated with oil and gas exploration may present concerns for bowhead whales. During icebreaki ng, extremely variable increases in broad-band (10-10,000 Hz) noise levels of 5-10 dB are cause d by propeller cavitation. Richardson et al. (1995a) reported estimated source levels fo r icebreakers to range from 177-191 db re 1 μ Pa-m. Based on previous studies of bowhead response to noise, such sound could result in temporary

avoidance of animals from the areas where the ic ebreakers were operating and potentially cause temporary deflection of the migration corridor, depending of the location of the icebreakers. Richardson et al. (1995) concluded that: “Ships and larger boats routinely use fathometers, and powerful side-looking sonars are common on many military, fishing, and bottom-survey

vessels.... Sounds from these sources must often be audible to marine mammals and apparently

cause disturbances in some situations .”

33Active sonars were used in commercial wh aling after World War II, and whaling boats sometimes tracked whales underwater using active sonar. Ash (1962), cited in Richardson et al., 1995a) reported that this ofte n caused strong avoidance by baleen whales. Reeves (1992) reported that ultrasonic pulses were used to sc are baleen whales to the surface. Maybaum (1990, 1993) reported that humpback whales on the winter ing grounds moved away from 3.3 kHz sonar pulses and increased their swimming speed and sw im-track linearity in response to 3.1- to 3.6- kHz sonar sweeps. We have no information that active sonar is currently an issue within the

action area.

Large research ships that are ac tive in the range of the bowhead s during periods when they are present have the potential to cause noise and disturbance to the wh ales, potentiall y altering their movement patterns or other behavior. Howeve r, available evidence does not indicate such disturbance will have a significant effect on th is population over the a pproximate life of the project, even when added to the effects of ot her effectors. The West ern Arctic bowhead has

been the focus of research activities that c ould, in some instances, cause minor temporary disturbance of the whales. During research on the whales themselves, the reactions of the whales generally are closely monitored to mini mize potential adverse eff ects. Additionally, research conducted primarily for reasons other than the study of the bowhead has also occurred within the range of the bowhead. In some cases, such research has the potential to adversely affect the whales through the in troduction of additional noise, di sturbance, and low levels of pollution into their environment.

Some of the research projects discussed here are continuing in the future, but have already been

initiated. Previous research on bowheads has in cluded aerial surveys, ship-based observations, acoustic studies, shore-based censuses, studies involving samples and examination of carcasses of animals killed in the subsistence hunt, and satellite tracking. NM FS recently initiated photoidentification studies. MMS will be procuring a large study aimed at better understanding the importance of feeding areas in the western Alaskan B eaufort Sea. In these fu ture activities, as in the past, the primary result of ship-based activi ties could be temporary di sturbance of individual whales from a highly localized ar ea. Whales might slightly and temporarily alter their habitat use to avoid large vessels. Whales also coul d be temporarily harasse d or disturbed by lowflying airplanes during photo-iden tification work. These effects would be as described for lowflying aircraft. All such effects are expected to be of short du ration. Aerial surveys generally are flown at a height such that they do not cause harassment.

Submarines are highly valued platforms for a variet y of oceanic research in part because they are relatively quiet, enabling the use of active and passive acoustic technologies for a variety of studies. U.S. Navy submarines are likely to conti nue to be used as platforms in the future. In recent years, there also have been scientific fiel d operations in the Arctic Ocean that have used U.S. Navy submarines as platforms. Other ship s have made numerous research trips into the range of the bowhead. For example, in 1995, the NRC reported that the Alpha Helix had performed numerous research cruises in the No rth Pacific, Bering Sea, Chukchi Sea, and Alaskan coastal waters over the past 15 years (NRC, 1995). Operation of this vessel is primarily limited to open water. The R/V Alpha Helix has modest ice-strengthen ing characteristics but no icebreaking capability.

34Humpback Whales Humpback whales are killed in cidentally in federal groundfish and longline fisheries and state managed-commercial salmon fisheries. The primar y source for data on incidental mortalities of humpback whales in commercial fisheries is from the North Pacific Groundfish Observer Program database (NMFS GOP) and Alaska Ma rine Mammal Observer Program. Data on entanglements and other interact ions with fishing gear is al so reported through NMFS’ Alaska Marine Mammal Stranding Network.

Until 2004, there were four different federally-re gulated commercial fisheries in Alaska that occurred within the range of the Central No rth Pacific humpback whale stock that were monitored for incidental mortality by fish ery observers: BSAI groundfish trawl, GOA groundfish trawl, longline, and pot fisheries. Average annual mortality from the observed fisheries was 1.5 (CV = 0.47) humpback whales fr om this population. As of 2004, changes in fishery definitions in the List of Fisheries have resulted in separating these four fisheries into 17 fisheries (69 FR 70094, 2 December 2004). This change does not represent a change in fishing effort, but provides managers with better informa tion on the component of each fishery that is responsible for the incidental serious injury or mortality of marine mammal stocks in Alaska. Between 2001 and 2005, there were incidental seri ous injuries and mortal ities of Central North Pacific humpback whales in the Bering Sea/Aleutia n Islands sablefish pot fishery. Estimates of marine mammal serious injury/mortality in obs erved fisheries can be found in Perez (2006).

Within the range of the Western North Paci fic humpback whale popul ation, there were six different federally-regulated comm ercial fisheries in Alaska that were monitored for incidental mortality by fishery observers unti l 2004. At that time, changes in fishery definitions in the List

of Fisheries have resulted in separating these six fisheries into 22 fisheries (69 FR 70094, 2 December 2004). Between 2000 and 2004, there were in cidental serious inju ries and mortalities of Western North Pacific humpback whales in the Bering Sea/Aleutian Islands sablefish pot fishery. Average annual mortality from observed fisheries was 0.20 humpbacks from this stock. Note, however, that the stock identification is uncertain and the mortality may have involved a

whale from the Central North Pacific stock of humpback whales. Thus, this mortality is assigned to both the Centra l and Western stocks.

No strandings or sightings of entangled hum pback whales from the Western North Pacific population were reported between 1999 and 2003; however, observing effort in western Alaska is low (Angliss and Outlaw 2006). The wester n population of humpback whales may be impacted by takes in other countries’ fisheries. Brownell et al. (2000) compiled records of bycatch of humpback whales in Japanese and Korean commercial fisheries between 1993 and 2000 and found that, during 1995-99, six humpback whal es were taken as bycatch. In addition, two strandings were reported by the Japanese or Korean during th is period. Analysis of four samples from meat found in Japanese markets in dicated that humpback whales are being sold (Angliss and Outlaw 2006). Where these animal s are taken, however, and whether they are taken intentionally or as by catch, is unknown (NMFS 2006a).

In recent years, an increasing number of entangl ed humpback whales have been reported to NMFS Alaska Region stranding program. Ninety -seven humpback whales were reported entangled in Alaska from 1997-2007; the majo rity of these involved southeast Alaska

35humpbacks (NMFS Alaska Region stranding data). For some of these reports, it remains unclear whether they represent distinct events or re-sights of the same entangled animal. For many of these reports, it is not possible to identi fy the gear involved in the entanglement to a specific fishery. This is based on a general lack of data in reports received, the difficulty in accurately describing gear at a distance, and the f act that most entanglements are not re-sighted for follow-up analysis. The majority of gear re ported in Alaska humpback whale entanglements involves crab, shrimp, and unidentified pot gear.

Ship strikes are also a human-caused source of injury and mortality for humpback whales. A compilation of available vessel co llision records to large whal es from 1975 to 2002 indicated that humpback whales are one of the most freque ntly hit species worldw ide (Jensen and Silber 2003). Of the database containing 292 records, humpback whales (44 records) were the second most commonly hit species after fin whales (75 records). In Alaska , numerous incidents of

vessel collisions have been docum ented, although there is no offici al reporting system for ship strikes. Fifty-four reports from 1986 to 2007 representing confirmed, unconfirmed and suspected ship strikes with humpback whales exis t in the NMFS stranding database. This is a minimum estimate, as not all whales struck are reported and not all whales struck are identified to species or cause of mortality. The fate of struck animals is al so not always determined unless the whale dies immediately upon impact or is disc overed as a carcass on the bow of a ship and it

can be determined that the strike was the cause of death.

Records of vessel collisions with large whales in Alaska indicate that strikes have involved cruise ships, recreational cruisers, whale watchi ng catamarans, fishing vessels, and skiffs. Vessel lengths associated with th ese records ranged from approxima tely 20 feet to over 250 feet, indicating that all types and sizes of watercraft pose a threat of collision for whales (Jensen and Silber 2003). This includes large commercial vesse ls such as cruise ship s, large tug and barge transport vessels, and oil transport tankers. Crui se ships are of particular concern, as they operate at considerably high speeds and frequent the inside waters of southeast Alaska with routes passing through areas of humpback whale abundance such as Glacier Bay National Park and Preserve, Point Adolphus and Lynn Canal. Oil transport tankers ar e generally operating

farther offshore where there are presumably fewer concentrations of humpback whales, except for transit through Prince William Sound. In additi on to large ships, which are most likely to cause significant injury or deat h to humpback whales, smaller t our, charter and private vessels also significantly overlap with inshore humpback whale distributi on in Alaska waters and also have the potential to cause disturbance, serious injury, and possibly mortality. Collisions in Alaska can occur throughout the regi on, peaking during the summer season.

No humpback whale stranding, entanglement or ship strike reports exist on file with NMFS for

the action area of the Chukchi and Beaufort Seas. At the time of this opinion, the number of entanglements in other parts of the state that might result in serious injury or mortality for humpback whales is not known to be at a level to have population level effects for the species. Although fishing effort in the Chukchi and Beaufo rt is currently minimal, with melting sea ice the industry may gradually move northward. Like wise, if warming continues, vessel traffic and shipping are expected to increase in the Arctic which may pose a gr eater threat of ship strike for humpback whales. In addition, the range of hum pback whales in the North Pacific may expand as conditions shift, resulting in a greater proba bility of interaction. Noise and pollution from

36vessels could also cause humpback whales to alter their movement patterns or make other changes in habitat use.

Fin Whales

Fin whales are killed and injured at least occasionally by inshore fishing gear (e.g., gillnets and lobster lines) off eastern Cana da and the United States (Read 1994; Lien 1994; Waring et al. 1997). Although the mortality from entanglement is thought to be much less for fin whales in proportion to population abundance than it is for many other species of baleen whales, more information is needed to evaluate this supposition. Prior to 1999, there were no observed or reported mortalities of fin whales incidental to commercial fishing operations within their North Pacific range. However, in 1999, one fin whale wa s killed incidental to the Gulf of Alaska pollock trawl fishery (Angliss and Outlaw 2008). There have been no records of fin whale fishery interactions or entanglem ents within the action area of the Chukchi and Beaufort Seas.

Ship strikes have injured or ki lled fin whales off both the U.S. east coast (Waring et al. 1997) and west coast. At least one, and probably more, fin whales were killed by collisions with ships off California in the early 1990s (Barlow et al. 1 997). In a report by Je nsen and Silber (2003) compiling large whale ship strikes world-wide, fin whales were th e species most often reported as victims of ship strike out of the eleven species evaluated. Seventy-five reports were compiled for fin whales, from locations along the U.S. eas t coast and Canada, Wash ington and California. Internationally, a number of ship strikes with fin whales have been reported from the Mediterranean Sea, France and Engl and (Jensen and Silber 2003).

According to Schevill et al. (1964), fin whales A seems somewhat to avoid ships. @ In Cape Cod waters, fin whales were notably wary of vessels before the mid-1970s, but since then they have become much less responsive to vessels (W atkins 1986). Edds a nd Macfarlane (1987) documented that a fin whale observed from an elevated site on the north shore of the St. Lawrence River significantly reduced its mean di ve time while it was being pursued by a ferry carrying whale watchers. Also in the St. La wrence, Michaud and Giard (1998) documented short-term changes in dive behavior of fin wh ales approached by vessels. Fin whales observed from a lighthouse in Maine responded to the pr esence of vessels by decreasing dive times, surface times, and number of blows per surfacing (Stone et al. 1992).

Fourteen stranding records exist for fin whales in Alaska between 1981-2006 in the Alaska Region marine mammal stranding database. For mo st of these cases, the cause of death could not be determined. However, two records of fi n whale ship strike exist; one in Uyak Bay in Kodiak in 2000, and one in Resurrection Bay near Seward in 2006.

Fin whales may also be subject to disturbance from human activities. The species attracts many whale-watching enterprises in eastern Canada a nd the northeastern Unit ed States (Hoyt 1984; Beach and Weinrich 1989). As a result, they ar e regularly subjected to close and persistent following by vessels in these areas. However, gi ven that fin whales are much less often subject to whale watching in the North Pacific than in th e North Atlantic, disturbance in the Pacific is more likely to come from the abundant industr ial, military, and fishing vessel traffic off the Mexican, U.S., and Canadian coasts than from the deliberate approaches of whale-watching vessels. The low-frequency sounds used by fin whales for communication and (possibly) in courtship displays (Watkins 1981) could be masked or interrupt ed by loud noise from ships, seismic testing, explosives, and other sources. In a study off Oregon, however, fin whales continued to produce their normal sounds desp ite the presence of seismic air gun pulses (McDonald et al. 1993).

37No evidence is available to indicate that m ilitary activities have had an impact on fin whale populations. However, concern about the potentia l for injury or disturbance to cetaceans influenced the siting and timing of ship-shock tr ials on the Scotian Shelf in November 1994 (see Reeves and Brown 1994), and off the California coast in June 1994. Recent military activities are not known to have had impacts on fin whales in the North Pacific. However, the large scale and diverse nature of military activ ities in this ocean basin mean that there is always potential for disturbing, injuring, or killing these and other whales (NMFS 2000).

No fin whale stranding, entanglem ent or ship strike reports ex ist on file with NMFS for the

action area of the Chukchi and Beaufort Seas. Currently, human impacts that might result in serious injury or mortality for fin whales in Alaska is not kn own to be at a level to have population level effects for the spec ies. Although fishing effort in the Chukchi and Beaufort is currently minimal, with melting sea ice the indus try may gradually move northward. Likewise, if warming continues, vessel traffic and shipping are expected to increase in the Arctic which may pose a greater threat of ship strike for fin whales. In additi on, the range of fin whales in the North Pacific may expand as conditions shift, re sulting in a greater probab ility of interaction. Noise and pollution from vessels could also cause fin whales to alter their movement patterns or make other changes in habitat use.

Pollution and Contaminants

Initial studies of bowhead tissues collected from whales landed at Barrow in 1992 (Becker et al., 1995) indicate that bowhead whales have very low levels of mercury, PCB’s, and chlorinated hydrocarbons, but they have fairly high concentra tions of cadmium in th eir liver and kidneys. The study concluded that the high concentration of cadmium in the liver and kidney tissues of bowheads warrants further investigation. Becker (2000) noted that conc entration levels of chlorinated hydrocarbons in bowhead whale blubbe r generally are an order of magnitude less than what has been reported for beluga whal es in the arctic. This probably reflects the difference in the trophic levels of these two species; the bowhead being a baleen whale feeding on copepods and euphausiids, while the beluga wh ale being a toothed whale feeding at a level higher in the food web. The concentration of tota l mercury in the liver also is much higher in beluga whales than in bowhead whales.

Bratton et al. (1993) measured organic arsenic in the liver tissue of one bowhead whale and

found that about 98% of the total arsenic was ar senobetaine. Bratton et al. (1997) looked at eight metals (arsenic, cadmium, copper, iron, mercury, lead, sele nium, and zinc) in the kidneys, liver, muscle, blubber, and visceral fat fr om bowheads harvested from 1983-1990. They

observed considerable variation in tissue metal concentration am ong the whales tested. Metal

concentrations evaluated did not appear to increase over time between 1983 and 1990. Based on metal levels reported in the literature for other baleen whales, the metal levels observed in all

tissues of the bowhead are similar to levels in other baleen whales. The bowhead whale has little metal contamination as compared to other arctic marine mammals, except for cadmium, which requires further investiga tion as to its role in human and bowhead whale health. The study recommended limiting the consumption of kidney from large bowhead whales pending

further evaluation.

Cooper et al. (2000) analyzed anthropogenic radi oisotopes in the epidermis, blubber, muscle, kidney, and liver of marine mammals harvested for subsistence food in nor thern Alaska and in

38the Resolute, Canada region. The majority of samples analyzed had detectable levels of 137 Cs. Among tissues of all species of marine mammals analyzed, 137 Cs was almost always undetectable in the blubber and significantly high er in epidermis and musc le tissue than in the liver and kidney tissue. The levels of anthr opogenic radioisotopes measured were orders of magnitude below levels that would merit public health concern. The st udy noted there were no obvious geographical differences in 137 Cs levels between marine mammals harvested in Resolute, Canada and those from Alaska. However, the 137 Cs levels in marine mammals were two to three orders of magnitude lower than the levels reported in caribou in northern Canada

and Alaska.

Based on the use of autometallogr aphy (AMG) to localize inorganic mercury in kidney and liver tissues for five bowhead whales, Woshner et al . (2002) reported that “A MG granules were not evident in bowhead tissues, confirming nominal mercury (Hg) concentr ations.” Detected concentrations ranged from 0.011-0.038 micrograms per gram (μg/g) wet weight for total mercury. Mössner and Ballschmiter (1997) reported that total levels of 310 nanograms per gram (ng/g) polychlorinated biphenyls and chlorinated pesticides in bowhead blubber from the North Pacific/Arctic Ocean, an overall level many times lower than that of other species from the North Pacific or Arctic Ocean (beluga whales [2,226 ng/g]; northern fu r seals [4,730 ng/g]) and than that of species from the North Atla ntic (pilot whale [6,997 ng/g]; common dolphin [39,131 ng/g]; and harbor seal [70,380 ng/g]). However, wh ile total levels were low, the combined level of 3 isomers of the hexachlorocyclohexanes was higher in the bowhead blubber (160 ng/g) tested than in either the pilot whale (47 ng/g) , the common dolphin (130 ng/g), and the harbor seal (140 ng/g). These results confirmed results expected due to the lower trophic level of the

bowhead relative to the other marine mammals tested.

In the Beaufort Sea multiple-sale EIS in 2003, MMS concluded that the levels of metals and other contaminants measured in bowhead whales appear to be relatively low, with the exception of cadmium. Since the finalization of the multiple-sale EIS, additional information (included in the review presented above) on contaminants in Western Arctic bowheads has become available. This information supports this same general conclusion.

In contrast to the available data on contamin ants in bowhead tissues, little information is available on contaminant levels for humpback a nd fin whales. Because these are not species which are subsistence hunted for consumption, fr esh tissue samples are fa r less readily available and must be collected through necropsies performed by the st randing network. Although little

data is available to form conclusions about contam inant levels in the tissues of these species, it is reasonable to assume that fin and humpback wh ales, as large mammals at a high trophic level, are susceptible to the bioaccumulation of orga nochlorine and metal contaminants through their regular diet of fish and euphausiids.

Offshore Oil- and Gas-Related Activities and other Industrial Activities Offshore petroleum exploration, development, a nd production activities have been conducted in

Alaska State waters or on the Alaska OCS in the Beaufort and Chukchi seas as a result of previous lease sales since 1979. Extensive 2D se ismic surveying has occu rred in both program areas. The MMS-permitted seismic surveys have been conducted in the Chukchi and Beaufort seas since the late 1960’s and early 1970’s. Mu ch more seismic activity has occurred in the

39Beaufort Sea OCS than in the Chukchi Sea OC S. The 2D marine seismic surveys in the Beaufort Sea began with two exploration geophy sical permits issued in 1968 and 4 in 1969. Both over-ice (29 permits) and marine 2D (43 permits) seismic surveys were conducted in the 1970’s. With one exception, all 80 marine and 43 over-ice surveys permitted in the Beaufort Sea OCS by MMS in the 1980’s were 2D. In the Beaufort Sea, 23 MMS G&G permits were issued in 1982 (11 marine and 12 over-ice 2D su rveys) and 24 MMS G&G permits were issued in 1983 (1, 3D over-ice survey; 14, 2-D over-ice survey s; and, 9, 2D marine surveys). The first 3-D on-ice survey occurred in the Beaufort S ea OCS in 1983. In the 1990’s, both 2D (2 on-ice and 21 marine) and 3D (11 over-ice and 7 marine OBC) seismic surveys were conducted in the Beaufort Sea. The first marine 3D seismic survey in the Beaufort Sea OCS occurred in 1996.

Thirty exploratory wells have been drilled in the Federal Beaufort over a 20+ year period between 1981 and 2002. This drilling occurred fr om a variety of drilling platforms (e.g., gravel islands, SSDC, drillships, etc.) and, during diffe rent seasons of the year, including the open water period. The last exploration well drilled in the Beaufort Sea OCS was drilled in the winter of 2002 at the McCovey prospect.

Compared to the North Slope/Beaufort Sea, there has been little oil- and gas-related activity in the Chukchi Sea. There is no existing OCS offs hore development or pr oduction in the Chukchi

Sea. Outer Continental Shelf Lease Sale 193 (Chukchi Sea OCS planning area) was held on February 6, 2008. Sale 193 offered approximately 12 million acres for leasing, and bids were received for over 1,100,000 acres. Fi ve exploratory wells have been drilled in the Chukchi Sea from past lease sales, all using drillships . These wells were drilled between 1989 and 1991,

inclusive. The last Chukchi Sea well was dr illed in 1991 at the Diamond Prospect. Recently several companies have conducted 2D/3D seismic work in the Chukchi, leading to Sale 193. Seismic work is expected to continue post-lease as prospect s are explored.

Many offshore activities also require ice manage ment (icebreaking), heli copter traffic, fixed wing monitoring, other support vessels, a nd, in some cases stand-by barges.

Available information does not indicate that oil- and gas-related activity (or any recent activity) has had detectable long-term adverse populati on-level effects on the overall health, current status, or recovery of the We stern Arctic bowhead whale popula tion. Data indicate that the Western Arctic population has continued to in crease over the timeframe that oil and gas

activities have occurred. There is no eviden ce of long-term displacement from habitat. However, there are no long-term oil and gas deve lopments in the offshore within bowhead high

use areas. Northstar is at the southern end of the migratory corridor a nd Endicott is within the

barrier islands. Past behavior al (primarily, but not exclusivel y, avoidance) effects on bowhead whales from oil and gas activity have been doc umented in many studies. Inupiat whalers have stated that noise from seismic surveys and some other activities at least temporarily displaces whales farther offshore, especially if the ope rations are conducted inthe main migration corridor. As noted in the section on effects, r ecent monitoring studies indicated that most fall migrating whales avoid an area with a radius about 20-30 km around a seismic vessel operating

in nearshore waters. We are not aware of data that indicate that such avoidance is long-lasting after cessation of the activity.

40Likewise, available information doe s not indicate that oil- and gas -related activity (or any recent activity) in the Chukchi and Beaufort has had detectable long-term adverse population-level

effects on the overall health, current status, or recovery of humpback and fin whales. At this time, we would expect little overlap of th ese activities with fin and humpback whale populations, given that the distribution of these sp ecies is limited in the Arctic and individuals have only been rarely sighted in this region. However, any reac tions to noise by these species would be expected to be similar to that of bowheads, given their common low frequency hearing range as baleen whales.

The MMS study 2002-071 titled GIS Geospatial Data Base of Oil-Industry and Other Human Activity (1979-1999) in the Alaskan Beaufort Sea provided a compilation of available data on the location, timing, and nature of oil- and gas-related activities from 1979-1999. It was intended to provide a “...databa se to address concerns expr essed by subsistence hunters and others living within ...villages of the Beaufort Sea about the possible e ffects that oil and gas activity, particularly seismic ac tivity, drilling, and oil and gas s upport vessel activ ities may have on the behavior of...especially the bowhead whale. ” However, “(S)uch an analysis requires an adequate level of detail...”, “...there are signifi cant gaps in the data for the period 1979-1989” (Wainwright, 2002) and “(V)ery limited info rmation was obtained on ice management” (Wainwright, 2002). For all but 2 years, 1985-1986, during the period 1979-1989, inclusive, Wainwright (2002) assessed th e availability of information about 2D/3D seismic surveys conducted under OCS permit as a 0 out of a possible 3. This score of 0 indicates: “Significant data sets are missing. These data are not suited for statistical analysis .” During this same period, they also provide a rank of 0 out of 3 to categorize the comple teness and adequacy of information on seismic surveys under state MLUP permit. For the entire period of study (1979- 1998), they rate the completeness and adequacy of information on seismic and acoustic surveys in State waters without permits, ice management, and other vessel activity all as 0. Thus, while

data on the bowhead status ar e adequate to determine that the Western Arctic population apparently continued to recover during the periods when past a nd current levels of oil and gas activities were occurring, we cannot adequately assess potenti al effects on patterns or durations

of bowhead habitat use. Wain wright (2002) summarized that “...it was not possible to compile adequate data on seismic activity prior to 1990.” Because of the inadequacy of the data on activities, and because of the limitations inhe rent in studying large baleen whales, we also

cannot assess whether there were any adverse health effects to individuals during the period of relatively intensive seismic surv ey activity in the 1980’s.

Data for the 1990s are better, and the levels of activity are more comparable to those anticipated in the near future. There were no geohazard (h igh-resolution seismic) surveys during the fall migration period in the 1990s (Wainwright 2002 ). Table 4 of Wainwright (2002) gives

information about the kinds and levels of seis mic and acoustic activity in the 1990s. Except in 1990 and 1998, seismic surveying activity was completed by September 30 th and most of the activity was between September 1-15. During 3 of the years, there was no seismic surveying activity during the fall migration period.

Data on past drilling in both fe deral and state waters is relati vely complete, especially since 1990. Data on other activities, such as hunting activity, barge traffic, and shipping noise are incomplete. Thus, while it is clear there have be en multiple noise and disturbance sources in the

41Beaufort Sea over the past 30 years, because of the incompleteness of data, even for the 1990s, for many types of activities, we cannot evaluate the totality of past effects on fin, humpback, or bowhead whales resulting from multiple noise and disturbance sources (e.g., 2D seismic in state and federal waters, drilling, ice-management, high -resolution acoustic surveys, vessel traffic, construction, geotechnical bore-hole drilling, aircra ft surveys, and hunting). Because data are also incomplete for the Chukchi Sea, we reach the same general conclusions.

Climate Change There is now widespread consensus within the scientific community that atmospheric temperatures on earth are increasing (warming) and that this will continue for at least the next several decades. There is also consensus within the scientific community that this warming trend will alter current weather patterns. The strongest warming is expected in the north, exceeding the estimate for mean global warming by a factor or 3, due in part to the “ice-albedo feedback”, whereby as the reflective areas of arc tic ice and snow retreat, the earth absorbs more heat, accentuating the warming (NRC 2003). The pr oximate effects of climate change in the arctic are being expressed as increased average winter and spring temper atures and changes in precipitation amount, timing, and type (Serreze et al. 2000). These changes in turn result in physical changes such as reduced sea ice, increased coastal er osion, changes in hydrology, depth to permafrost, and carbon availability (ACIA 2005).

The IPCC (2001b) also highlights uncertainty and inconsistencies in loca l and regional model projections and the ability to predict quantitative changes at th ese scales due to the capabilities of regional scale models (espec ially regarding precipitation).

The IPCC (2001b) concluded that:

Human activities have increased the atmosphe ric concentrations of greenhouse gases and aerosols since the preindustrial era. An increasing body of observations gives a co llective picture of a warming world and other changes in the climate system. On a global basis, it is very likely that 1998 was the warmest year and the 1990’s was the warmest decade in instrumented history (1861-2000) (IPCC, 2001a,b). There is new and stronger evidence that mo st of the warming observed over the last 50 years is attributable to human activiti es.... The best agr eement between model

simulations and observations over the last 140 years has been found when all...anthropogenic and natural forcing fact ors are combined” (see Figure SPM-2 of IPCC, 2001b).

Changes in sea level, snow cover, ice extent, and precipitation are cons istent with a warming climate near the Earth’s surface. The IPCC ( 2001b) noted “Examples include...increases in sea level and ocean-heat content, and decreases in sn ow cover and sea-ice extent and thickness” and

consider their statement that “rise in sea leve l during the 21st century that will continue for

further centuries” to also be a “robust finding.” However, they highlight the uncertainty of understanding the probability di stribution associated with bo th temperature and sea-level projections.

42The 4th Assessment Report of the Intergovernme ntal Panel on Climate Change (IPCC 2007) reports that warming will be greatest over land an d at most high northern latitudes. They also predict the continuation of recent observed trends such as contraction of snow cover area, increases in thaw depth over most permafrost regi ons, and decrease in sea ice extent. Projected surface temperature changes along the North Slop e of Alaska may increase by 6.0-6.5 degrees C for the late 21st century (2090-2099), relative to the period 1980-1999 (IPCC 2007)

The IPCC’s projections using the Special Repor ts on Emissions Scenarios (SRES) emissions scenarios in a range of climate models result in an increase in globally averaged surface temperature of 1.4-5.8 oC over the period 1990-2100. Th is is about 2-10 times larger than the

central value of observe d warming over the 20 th century, and the projecte d rate of warming is very likely to be without precedent during at least the last 10,000 years, based on paleoclimate data. For the periods 1990-2025 and 1990-2050, th e projected increases are 0.4-1.1 oC and 0.8- 2.6 oC, respectively (IPCC, 2001b).

At the request of the White H ouse, the NRC (NRC, 2001) identif ied areas in the science of climate change where there are the greatest cert ainties and uncertainties. In answer to the question of whether climate change is occurr ing and, if so, how, the NRC (2001) wrote that:

Weather station records and ship -based observations indicate that global mean surface air temperature warmed between about 0.4 and 0.8 C...during the 20 th century...the warming trend is spatially widespread and is consistent with an array of other evidence...in this report. The ocean....has warmed by about 0.05 C...averaged over the layer extending from the surface down to 10,000 feet, since the 1950s.

The NRC concluded:

The IPCC’s conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accu rately reflects the current thinking of the scientific community on this issue. The stated degree of confidence in the IPCC assessment is higher today than it was 10, or even 5 years ago, but uncertainty remains....

The NRC (2001) also concluded that: “The predicted warming is larger over higher latitudes than over low latitudes, especia lly during winter and spring, and la rger over land than over sea.”

A general summary of the changes at tributed to the current trends of arctic warming indicate sea ice in the Arctic is undergoing ra pid changes. There are report ed changes in sea-ice extent, thickness, distribution, age, and me lt duration. In general, the s ea-ice extent is becoming much less in the arctic summer and slig htly less in winter. The thickness of arctic ice is decreasing.

The distribution of ice is changing, and its age is decreasing. The melt duration is increasing.

These factors lead to a decreasing perennial arctic ice pack. It is generally thought that the Arctic will become ice free in summer, but at th is time there is consider able uncertainty about when that will happen.

43Predictions of future sea-ice ex tent, using several climate models and taking the mean of all the models, estimate that the Arctic will be ice free during summer in the latter part of the 21 st
century (IPCC, 2007). There is considerable uncerta inty in the estimates of summer sea ice in these climate models, with some predicting 40-60% summer ice loss by the middle of the 21 st
century (Holland, 2006). Using a su ite of models, a 40% loss is estimated for the Beaufort and Chukchi seas (Overland and Wang, 2007). Some investigators, citi ng the current rate of decline of the summer sea-ice extent believe it may be sooner than predicted by the models, and may be as soon as 2013 (Stroeve et al., 2007). Other inve stigators suggest that va riability at the local and regional level is very important fo r making estimates of future changes.

The sea ice was gone; there’s no main ice pack anymore. All of its just floating ice. There are just small pieces of ice. When I first went out whaling, I saw big icebergs, but

not now. The ice is too far out to see it. In the 1970s and 1980s the ice was close. You didn’t have to go far to see it. Now you don’t see any glacier ice at all.” (Footnote 8, personal interview, October 5, 2004, as cited by McBeath and Shepro, 2007).

The extent of winter sea ice, generally measur ed at the maximum in March, began changing in

the late 1990’s and has declin ed through 2006 (Comiso, 2006; Stro eve et al., 2007; Francis and Hunter, 2007). Comiso (2006) attributed the cha nges to corresponding changes in increasing surface temperature and wind-driven ice motion. The factors causing the reduction in the winter

sea-ice extent are different from those in the su mmer. The reduction of the winter sea-ice extent in the Bering Sea preconditions the environmen t during the melt season for the Chukchi Sea. The end-of-winter perennial sea- ice extent was the smallest on record in March 2007 (Nghiem et al., 2007). The arctic sea ice reached its maximum on March 10, 2008. Although the maximum in 2008 was greater than in 2007, it was below aver age and was thinner than normal (Martin and Comiso, 2008; University of Colorado, NSDIC, 2008).

While changes in the reduction of summer sea-ice ex tent are apparent, the cause(s) of change are not fully established. The evidence suggests that it may be a combination of oceanic and atmospheric conditions that are causing the change . Incremental solar h eating and ocean heat flux, longwave radiation fluxes, changes in surf ace circulation, and less multiyear sea ice all may play a role.

These changes are resulting, or are expected to re sult, in changes to the biological environment, causing shifts, expansion, or retr action of home range, changes in behavior, and changes in population parameters of plant and animal species. Much research in recent years has focused on the effects of naturally-occurri ng or man-induced global climate re gime shifts and the potential for these shifts to cause changes in habitat struct ure over large areas. Although many of the forces driving global climate regime shifts ma y originate outside the Arctic, the impacts of global climate change are exacerbated in the Ar ctic (ACIA 2005). Temperatures in the Arctic

have risen faster than in othe r areas of the world as evidence d by glacial retreat and melting of sea ice. Threats posed by the direct and indirect effects of global climatic change are or will be common to Northern species. These threats wi ll be most pronounced for ice-obligate species such as the polar bear, walrus, and ringed seal.

44However, not all arctic species are likely to be adversely influenced by global climate change. Conceptual models by Moore and Laidre (2006) suggested that, overall, reductions in sea ice cover should increase the Bering-Chukchi-B eaufort Sea stock of bowhead whale prey availability.

This theory may be substantiated by the st eady increase in the BCBS population during the nearly 20 years of sea ice reductions (Walsh 2008). Moore and H untington (2008) anticipate that bowhead whales will alter migration routes and occupy new feeding areas in response to climate related environmental change. Sheldon et al. (2003) notes that there is a high probability that bowhead abundance will increase under a warming global climate.

The recent observations of humpback and fin whal es in the Beaufort and Chukchi seas may be indicative of seasonal habitat expa nsion in response to receding sea ice or increases in prey availability which these whales now exploit. Range expansions in response to habitat change

are not uncommon among cetaceans. Gray whales in Alaska have shown pronounced change over the last several decades; overwintering at hi gher latitudes and occupying previously lesserused feeding areas in the Beaufort Sea. Concentrations of th e rare North Pacific right whale

were first observed in the southeast Beri ng Sea in 1996 and have continued until recently, possibly reflecting changes in z ooplankton distribution due to la rge-scale oceanographic change within the Bering Sea. Since humpback and fi n whales are not ice-obligate or ice-associated species, it is unknown how long this ha bitat will remain viable for the species. However, it is logical to assume these whales will continue to utilize these waters as long as the availability of prey remains.

IV. EFFECTS OF THE ACTION One of the greatest concerns associated with the impacts of oil and ga s exploration on marine mammals has to do with potential impacts of noise. During OCS oil and gas exploration, human-caused noise is transmitted through the air a nd through marine waters from a variety of sources including, but not limited to: 2D/3D seismic surveys; pi peline, platform, and related shore-based construction; drilling; icebreakers and other ships, barge transit; high-resolution seismic surveys; and helicopter and fixed-winged aircraft traffic. Because of the importance of this issue, we provide two background sections. The first provides very general information relevant to understanding the fate of noise in the marine environment. The second provides general background about potential types of effects of noise on marine mammals.

Background on Noise in the Marine Environment Properties of sound that influence how far that sound is transmitted, what species hear it, and what physical and behavioral e ffects it can have include the fo llowing: its intensity, frequency, amplitude, wavelength, and duration; distan ce between the sound source and the animal; whether the sound source is moving or stationary ; the level and type of background noise; and the auditory and behavioral sensitivity of the species (Richardson et al., 1995a). The frequency of the sound is usually measured in hertz (Hz), pressure level in micropascals (μP) (Gausland, 1998), and intensity levels in decibels (dB) (Ric hardson et al., 1995a; Mc Cauley et al., 2000). McCauley et al. (2000) and others (see references in McCauley et al., 2000) express this in terms of its equivalent energy decibels re 1 μPa 2

. The perceived loudness of any given sound is influenced by many factors including both the frequency and pressure of the sound (Gausland,

451998), the hearing ability of th e listener, the leve l of background noise, and the physical environment through which the sound traveled before reaching the animal. Based on summaries in key references (e.g., Richardson et al, 1995a ; Gausland, 1998; and Ketten, 1998), and other references as noted, the following informati on about sound transmission is relevant to understanding potential impacts of sound on marine mammals:

1. Sound travels faster and with less atte nuation in water th an it does in air.

2. The fate of sound in water can vary greatly, depending on characteristics of the sound itself,

characteristics of the location where it is released, characteristics of the environment through which it travels (Richardson et al., 1995a; McCauley et al., 2000) , and the characteristics (for example, depth, orientation) of the recei ver (Richardson et al., 1995a; Gausland, 1998).

3. Sound propagation can vary seasona lly in the same environment.

4. Extrapolation about the likely impacts of a given type of sound source in a given location

within the Chukchi Sea or Beau fort Sea OCS Planning Areas on a particular marine mammal, based on published studies conducted elsewh ere, are somewhat speculative because

characteristics of the marine environment such as bathymetry, sound-source depth, and seabed properties greatly impact the propagation of s ound horizontally from the source (McCauley et al., 2000; see also Chapter 4 in Richardson et al., 1995a and references provided therein). Richardson et al. (1995a:425) su mmarized that: “...a site-speci fic model of sound propagation is needed to predict received sound levels in relation to dist ance from a noise source.” Especially within the Chukchi S ea Planning Area, differences in si te characteristics in different parts of the planning area make predictions about sound propagation relatively difficult.

5. There is a great deal of natu rally occurring noise in the oc ean from volcanic, earthquake, wind, ice, and biotic sources (see Richardson et al., 1995). Ambient noise levels affect whether a given sound can be detectable by a receiver, including a living receiver, such as a whale. Ambient noise levels can change greatly throughout the course of a season at a particular site, and vary from site to site.

6. Because the air-water interface acts as a good reflector, sound generated underwater generally will not pass to the air (Gausland, 1998).

General Background on Potential Effects of Noise and Disturbance on Cetaceans In this section, we provide background about pot ential effects of impact s of OCS oil- and gasrelated noise and disturbance. This section shoul d not be interpreted as indicating effects that are likely to occur due to the proposed actions on the bowhead whale, humpback or fin whale. Hearing (auditory) systems and perception are speci es specific and habitat dependent. As noted in the previous section, and elsewh ere in this evaluation, the fate of sound after it is produced is also site (especially in the ar ctic), season, and weathe r specific. Because of these fundamental facts, the potential for a given s ound to cause adverse effects to an animal also is species specific and habitat dependent. Because of differences in bathymetry and seabed characteristics of sites throughout the Chukchi Sea and Be aufort Sea Planning Areas, th e distances that sounds of

46various frequencies, intensities, and pressures will propagate, and the resulting effects such sounds could have, also are expected to differ greatly among specific sites (for example, among specific leasing blocks that di ffer in seabed properties, bath ymetry, and the amount of wave action). Thus, the exact location of any sound s ource will determine the fate of sound released at that site and, therefore, will affect the possi bility of impact on threatened and endangered species in or near the area. The time of year su ch sound is released will determine whether there is potential for individuals of a speci es to be exposed to that sound.

Many marine mammals rely primarily on hearin g for orientation and communication (e.g., Erbe and Farmer, 1998; NRC, 2003, 2005). The scientific community generally agrees that hearing is an important sense used by cetaceans (for ex ample see Richardson et al., 1995; NRC, 2003, 2005; National Resources Defense Council (NRD C), 1999, 2005; Marine Mammal Commission Sound Advisory Panel Minutes from meetings, MMC website). Marine mammals rely on sound to communicate, to find mates, to navigate, to or ient (Erbe et al. 1999), to detect predators, and to gain other information about their environment. Because of their reliance on hearing, there is an increasing concern about th e impacts of proliferation of anthropogenic noise on marine mammals, especially cetaceans. NMFS (Carretta et al. 2001) summarized that a habitat concern for all whales, and especially for baleen whales, is the increasing level of human-caused noise in

the world’s oceans. Increased noise levels could interfere with communication among whales, mask important natural sound, cau se physiological damage, or alter normal behavior, such as causing avoidance behavior that keeps animals fr om an important area or displace a migration

route farther from shore. Noise from various sources has been shown to affect many marine mammals (e.g. Richardson et al. 1995; Kraus et al. 1997; NRC 2003; 2005) in ways ranging from subtle behavioral and physiolo gical impacts to fatal effects.

Several important documents that summarize info rmation on this topic in clude: Richardson et al. (1995a); Hoffman (2002); Tasker et al. (1998); NRC (2003, 2005) ; National Resources Defense Council (NRDC) (1999, 2005); IWC (2004a). Two pa rticularly relevant summaries by the NRC have occurred within the last few years: Ocean Noise and Marine Mammals (NRC, 2003) and

Marine Mammal Populations and Ocean Noise, Dete rmining when Noise Causes Biologically Significant Effects (NRC 2005). The IWC (2004) Scien tific Committee Standing Working Group on Environmental Concerns held a mini sy mposium on acoustics w ith a section of the report dealing with seismic surveying. Lastly, the Marine Ma mmal Commission (MMC) convened an Advisory Committee on Acoustic Im pacts on Marine Mammals which is producing summaries of areas of agreement and disagreeme nt concerning the impacts of noise on marine mammals as well as a summary from a subcommittee on mitigation and management of anthropogenic noise.

Results from several experimental studies have been published regarding sound exposure metrics incorporating sound pressure leve l and exposure duration. Recently, several investigators have examined noise-induced tempor ary threshold shift (TTS) in hearing in some odontocetes and pinnipeds exposed to moderate levels of underwater noise of various bandwidths and durations. Kastak et al. (2005) summarized that “Because exposure to...noise in the marine environment is sporadic and inte rrupted, it is necessary to examine variables associated with varying noise sound pressure levels, intermittence of exposure, and total acoustic energy of exposure, in order to accura tely predict the effects of noise on marine

47mammal hearing. ” However, while there is scientific acknowledgement of this statement, there

are few instances where data are sufficient to evaluate the total ener gy exposure of a marine mammal from a given source. We acknowledge that evaluation of total energy could change our analyses. However, at present, we do not have th e data necessary to make such a determination.

Despite the increasing concern and attention noted above, there is still uncertainty about the potential impacts of sound on marine mammals , on the factors that determine response and effects, and especially, on the long-term cumu lative consequences of increasing noise in the world’s oceans from multiple sources (e .g., NRC, 2003, 2005). The NRC (2005) Committee on Characterizing Biologically Significant Marine Mammal Behavior conc luded that it is unknown how or in what cases responses of marine mammals to anthropogeni c sound rise to the levels of biologically significant eff ects. This group also developed an approach of injury and behavioral “Take equivalents”. These take equivalents use a Severity Index that estimates the fraction of a take experienced by an individual animal. This severity index is higher if the activity could be causing harassment at a critical lo cation or during a cri tical time (e.g., calving habitat). Because we have uncertainty about exactly where and how much activity will occur in a given year, we incorporate recommendations from the NRC (2005) qualitatively. Available evidence indicates that reaction to sound, even within a species, may depend on the listener’s sex and reproductive status, possibly age and/or accumulated hearing da mage, type of activity engaged in at the time or, in some cases, group size. For example, reaction to sound may vary depending on whether females have calves accompanying them, or whethe r individuals are feedi ng or migrating. It may depend on whether, how often, and in what context, the individual animal has heard the sound before. All of this specificity greatly co mplicates our ability, in a given situation, to predict the impacts of sound on a species or on classe s of individuals within a species. Because of this, and following recommendations in McCa uley et al. (2000), we attempt to take a conservative approach in our analyses and base conclusions about potential impacts on potential effects on the most sensitive members of a population. In addition, we make assumptions that sound will travel the maximums observed elsewhere, rather than minimums. While there is some general information available, evaluation of the impacts of noise on marine mammal species, particularly on cetaceans, is greatly hampered by a considerable uncertainty about their hearing capabilities and the range of sounds used by the whales for different functions (Richardson et al., 1995a; Gordon et al., 1998; NRC, 2003, 2005). This is particularly true for baleen whales. Very

little is known about the actual hearing capabilities of the la rge whales or the impacts of sound on them, especially physical effects. While research in this area is increasing, it is likely that we will continue to have great uncertainty about ph ysiological effects on bale en whales because of the difficulties in studying them. Baleen whale h earing has not been studied directly. There are no specific data on sensitivity, frequency or intensity discrimination, or localization (Richardson et al., 1995a). Thus, predictions about probable impact on baleen whales generally are based on assumptions about their hearing ra ther than actual studies of th eir hearing (Richardson et al., 1995a; Gordon et al., 1998; Ketten, 1998). Ketten (1998) summarized that the vocalizations of most animals are tightly linked to their peak hear ing sensitivity. Hence, it is generally assumed

that baleen whales hear in th e same range as their typical voc alizations, even though there are no direct data from hearing tests on any baleen whal e. Most baleen whale sounds are concentrated at frequencies less than 1 kHz, but the fre quency range in bowhead songs can approach 4,000 Hz (Richardson et al., 1995a). Most calls em itted by bowheads are in the frequency range of 50- 400 Hz, with a few extending to 1,200 Hz. Based on indirect evidence, at least some baleen

48whales are quite sensitive to frequencies below 1 kHz but can hear sounds up to a considerably higher but unknown frequency. Most of the manmad e sounds that elicited reactions by baleen whales were at frequencies below 1 kHz (Richards on et al., 1995a). Some or all baleen whales may hear infrasounds, sounds at frequencies well below those detectable by humans. Functional

models indicate that the functiona l hearing of baleen whales ex tends to 20 Hz, with an upper range of 30 Hz. Even if the range of sensit ive hearing does not extend below 20-50 Hz, whales may hear strong infrasounds at considerably lo wer frequencies. Based on work with other marine mammals, if hearing sensitivity is good at 50 Hz, strong infrasounds at 5 Hz might be detected (Richardson et al., 1995a). Bowhead wh ales, as well as blue and fin whales, are predicted to hear at frequencies as low as 10-15 Hertz. McDonald, Hildebrand, and Webb (1995) summarize that many baleen whales pr oduce loud low-frequency sounds underwater a significant part of the time. T hus, species that are likely to be impacted by low-frequency sound include baleen whales such as fin, humpback, and bowhead whales.

Most species also have the abil ity to hear beyond their peak range. This broader range of hearing probably is related to their need to detect other important environmental phenomena, such as the locations of predator s or prey. Ketten ( 1998:2) summarized that, “The consensus of the data is that virtually a ll marine mammal species are potentially impacted by sound sources with a frequency of 500 Hertz or higher. This st atement refers solely to the probable potential for marine mammal species to hear sounds of various frequencies. If a species cannot hear a sound, or hears it poorly, then the sound is unlikel y to have a significant effect. Other factors, such as sound intensity, will determine whether the specific sound reaches the ears of any given

marine mammal. ” Considerable variation exists among marine mammals in hearing sensitivity and absolute hearing range (R ichardson et al., 1995; Ketten, 1998). Because of suspected differences in hearing sensitivity, it is likely that baleen whales and pinnipeds are more likely to be harmed by direct acoustic impact from low- to mid-sonic range devices than odontocetes. Conversely, odontocetes are more likely to be harmed by high-frequency sounds.

Little data are available about how most marine mammal species, especially large cetaceans, respond either behaviorally or phys ically to intense sound and to long-term increases in ambient noise levels, especially over the long term. Large cetaceans cannot be easily examined after exposure to a particular sound source.

Whales often continue a certain activity (for ex ample, feeding) even in the presence of airgun, drilling, or vessel sounds. Such continuation of activity does not confirm that the sound is not harmful to the cetacean. In many or all cases, this may be true: it may not be harmful. However, this type of interpretation is specula tive. Whales, other mari ne mammals, and even humans, sometimes continue with important beha viors even in the presence of noise or other potentially harmful factors. Whales often fast for long lengths of time during the winter. The need to feed or to transit to feeding areas, for example, is possibly so great that they continue with the activity despite being harmed or bot hered by the noise. For example, Native hunters reported to Huntington (2000) that beluga whales often ignore the approach of hunters when feeding, but at other times will a ttempt to avoid boats of hunters.

Potential damage to hearing Ketten (1998) reported that hearing loss can be caused by exposure to sound that exceeds an ear’s tolerance (i.e., exhaustion or overextension of one or more ear components). Hearing loss

49to a marine mammal could result in an inabilit y to communicate effectively with other members of its species, detect approaching predators or ve ssels, or echolocate (in the case of the toothed whales). Hearing loss resulting from exposure to s ound often is referred to as a threshold shift. Some studies have shown that following expos ure to a sufficiently intense sound, marine mammals may exhibit an increased hearing thre shold, a threshold shift, after the sound has ceased (for example, Nachtigall et al., 2004; Ka stak et al., 1999; Schl undt et al., 2000; Finneran et al., 2002). Thus, a threshol d shift indicates that the sound exposure resulted in hearing loss causing decreased sensitivity. This type of hearing loss is called a temporary threshold shift if the individual recovers its pr e-exposure sensitivity of hearing over time, or a permanent

threshold shift if it does not.

Ketten (1998) reported that whethe r or not a temporary threshold shift or a permanent threshold shift occurs will be determined primarily based on the extent of inner ear damage the received sound and the received sound level causes. In ge neral, whether a given species will tend to be damaged by a given sound depends on the frequenc y sensitivity of the species. Long-lasting increases in hearing thresholds, which also can be described as long-lasting impairment of hearing ability, could impair th e ability of the affected marine mammal to hear important communication signals or to interp ret auditory signals. Most experiments have looked at the characteristics (for example, intensity, frequenc y) of sounds at which temporary threshold shift and permanent threshold shift occurred. However, while research on this issue is occurring, it is still uncertain what the impacts may be of rep eated exposure to such sounds and whether the

marine mammals would avoid such sounds after exposure even if the exposure was causing temporary or permanent hearing damage if they were sufficiently motivated to remain in the area (for example, because of a concentrated f ood resource). There are not data on which to

determine the kinds or intensi ties of sound that could cause a TTS in a baleen whale. Permanent threshold shifts are less species depe ndent and more dependent on the length of time the peak pressure lasts and the signal rise time. Usually if exposure time is short, hearing sensitivity is recoverable. If exposure to th e sound is long, or if th e sound is broadband in higher frequencies and has intense sudden onset, loss might be permanent. Repeated long exposures to intense sound or sudden onset of intense sounds ge nerally characterize sounds that cause permanent threshold shift in humans. Ketten (1998) stated th at age-related hearing loss in humans is related to the accumulation of perm anent-threshold-shift and temporary-thresholdshift damage to the ear. The NRC (2005) concl uded that: “...there is evidence of age-related hearing loss ” in marine mammals. A very powerful s ound at close range can cause death due to rupture and hemorrhage of tissues in lungs, ears, or other parts of the body. At greater distance, that same sound can cause temporary or permanen t hearing loss. Noise can cause modification of an animal s behavior (for example, appr oach or avoidance behavior, or startle).

Long-term impacts of OCS seismic survey noise on the hearing abilities of individual marine

mammals are unknown. Information about the hear ing capabilities of larg e baleen whales is mostly lacking. As noted previously, the assump tion is made that the area of greatest hearing sensitivity are at frequencies known to be us ed for intraspecific communication. However, because real knowledge of sound sensitivity is lacking, we assume in our analyses that sensitivities shown by one species of baleen whale also could appl y to another. This assumption is conservative, especially when using studies on a species such as the humpback, which uses a

50large sound repertoire in intraspecific communi cation, to infer possible impacts on other species

such as the fin whale.

Masking When noise interferes with sounds used by the ma rine mammals (for exam ple, interferes with their communication or echolocation), it is said to “mask” the sound (for example, a call to another whale might be masked by an icebreaker operating at a certain distance away). Noises can cause the masking of sounds that marine ma mmals need to hear to function (Erbe et al. 1999). That is, the presence of the masking noise can make it so that the animal cannot discern sounds of a given frequency and at a given level that it would be able to do in the absence of the masking noise. If sounds used by the marine mammals are masked to the point where they cannot provide the individual with needed in formation, harm can re sult (Erbe and Farmer, 1998). In the presence of the ma sking sounds, the sounds the animal needs to hear must be of greater intensity for it to be able to det ect and to discern the information in the sound. Erbe and Farmer (1998) summarize that in “...the human and dolphin ear, low frequencies are more effective at masking high frequencies than vice versa ; masking is maximum if the characteristic frequencies of the mask er are similar to those of the signal ...” They proposed that the factor most important for determining the ma sking effect of the noi ses was their temporal

structure. The noise that was the most conti nuous with respect to frequency and time masked the beluga vocalization most effectively, wher eas sounds (for example, natural icebreaking noise) that occurred in sharp pulses left quiet bands in between and left gaps through which the beluga could detect pieces of the call. In a given environment, then, the impact of a noise on cetacean detection of signals likely would be in fluenced by both the frequency and the temporal characteristics of the noise, its signal-to-noise ratio, and by the same characteristics of other sounds occurring in the same vicinity (for exampl e, a sound could be intermittent but contribute to masking if many intermittent noises were occu rring). It is not known whether (or which) marine mammals can (Erbe and Farmer, 1998) an d do adapt their vocalizations to background

noise.

Behavioral Reactions

Available evidence also indicates that behavioral reaction to sound, even within a species, may depend on the listener’s sex and reproductive stat us, possibly age and/or accumulated hearing damage, type of activity engaged in at the time or, in some cases, on group size. For example, reaction to sound may vary de pending on whether females have calves accompanying them, whether individuals are feeding or migrating. Response may be influenced by whether, how often, and in what context, the individual an imal has heard the sound before. All of this specificity greatly complicates our ability, in a gi ven situation, to predic t the behavioral response of a species, or on classes of individuals within a species, to a given sound. Because of this, and following recommendations in McCauley et al. (2000) (discussed above), we attempt to take a conservative approach in our analyses and base conclusions about potential impacts on potential effects on the most sensitive members of a populati on. In addition, we evaluate the potential for effects on fin, humpback, and bowhead whales by making the implicit assumptions that sound may travel the maximums observed, rather than minimums and that whales engaged in a particular activity may respond at the maximum, not the minimum, distances observed in studies to date. These assumptions overestimate potential effect in many cases. However, since at least

51some of the airgun arrays being used in the Chuk chi and Beaufort Seas have greater total output than many of those in previous studies, we may also underestimate impact in some cases.

Potential Exposure of Whales to Seismic Survey Activities Bowhead whales have documented use of portio ns of both the Chukchi Sea and Beaufort Sea evaluation areas for: spring and fall migration; feeding; calving; resti ng; and limited breeding. Most of the calving for this population probably occurs between the Bering Strait and Point

Barrow. Bowhead whales have a demonstrated sensitivity to some noise and disturbance, including noise and disturbance from seismic surveys. It is clear that if 2D/3D seismic surveys impacted areas of the spring lead and polynya system during the spring migration, impacts could be potentially biologically signifi cant. We note that the genera l location of th e spring lead system in the Chukchi and Beaufort seas is based on relatively limited survey data and is not well defined. Noise-producing activities, such as seismic surveys, in the spring lead system during the spring bowhead migration have a fa irly high potential of affecting the whales, including females with newborn calves. Fin wh ale distribution in the action area appears very limited, and restricted to the Chukchi Sea during summer months. Humpb ack whales are also likely to occur only seasonally, predominatel y within the Chukchi Sea, although humpback

whales were observed in the western Beaufo rt Sea in 2007. Thus, both fin and humpback whales may occur in waters subject to seismic survey.

Sources of Noise and Disturbance from Seismic Surveys During OCS oil and gas 2D/3D seismic explor ation, human-caused noise can be transmitted through the air and through marine waters from a variety of s ources including, but not limited to:

the seismic noise sources themselv es that purposely release noise into the water; icebreakers, other ships, and boats; hi gh-resolution seismic surveys; and helicopter and fixed-winged aircraft traffic. Endangered cetaceans conceivably could be disturbed or struck by ships or boats during seismic surveys. Small fuel spills could occur. Any or all of these factors potentially could adversely affect bowhead whales in and/or near the Chukchi Sea or Beaufort Sea Planning Areas during OCS oil and gas seismic exploration activities.

Sound from seismic exploration is a potential so urce of noise disturbance to bowhead, fin and humpback whales in and near areas where the surveys may occur. Marine seismic operations use high-energy airguns to produce a burst of unde rwater sound from the release of compressed air, which forms a bubble that rapidly expands a nd then contracts. Typically, seismic sources used in such surveys involve th e rapid release of compressed ai r to produce an impulsive signal

that is directed downward thr ough the seabed. Thus, the source for the sound is called an airgun.

Seismic airguns are meant to produce low-fre quency noise, generally below 200 Hz. However, the impulsive nature of the collapse of the ai r bubbles inevitably re sults in broadband sound characteristics. Goold (1996, cited in Stone, 2001) reported that high-frequency noise is also produced. Goold also found significant levels of energy from airguns across the bandwidth up to 22 kilohertz. Seismic surveys using airguns, especially 2D and 3D seismic surveys, produce at the source, underwater sound levels exceeding those of other activities discussed in this

section. This means animals sensitive to either low-frequency or high-fr equency sounds may be affected. Bowhead whales emit tonal frequenc y modulated sounds at 50-400 Hz. A few calls

52have energy extending to 1,200 Hz. Bowheads al so emit impulsive sounds in the frequency range of 25-3,500 Hz, as well as songs of about 20-500 Hz (Richardson et al. 1995a). Airgun arrays are designed to focus the sound energy downward. Despite this , sound pulses also are projected horizontally, with the distance travel ed depending on many factors, such as those discussed by Richardson et al. (1995a) and McCauley et al. (2 000). Airgun arrays produce short-duration (transient) noise pulses with ve ry high peak levels. The high peak level and impulsive nature of airguns have caused concern in the scientific and environmental

communities.

McCauley et al. (2000) concluded that the most consistent measure of a received airgun signal was a measure of its energy, as was suggested by Richardson et al. (1995) for pulsed sounds. In Alaska, 2D/3D seismic surveying, during which large areas are surveyed to obtain information on the subsurface, are generally undertaken before a proposed lease sale. The 2D/3D seismic surveys are also undertaken after lease sales or between one lease sale and the next. On-lease high-resolution seismic profiling usually is undertaken for engineering purposes to determine the suitability of locations for emplacement of seafloor-founde d structures (drilling rigs, platforms, pipelines). The energy level in these types of surveys is much lower than that used in the 2D/3D seismic surveys; thus, the ra dius of noise exposure is many times smaller. Seismic surveys often employ ot her activities that may result in an increase in noise and disturbance to whales (see below). Seismic sh ips have navigational equipment that produces noise, and the ships themselves introduce noise, cause disturbance and may strike cetaceans.

Marine vessel traffic and aircrafttraffic, in support of the surveys and used in marine mammal monitoring, all introduce noise a nd disturbance into the marine environment, with potential adverse impacts on the whales.

McCauley et al. (2000) stated th at a precise definition of the s eabed to at least 50-100 m is required to accurately predict hori zontal propagation along a travel path

. Based on experimental measurement of signals from a single airgun, McCa uley et al. (2000) found signal differences of airgun broadband levels of up to 10 dB at a 1- km range. They concl uded that such large differences in levels, measured for the same source at a given range within the same bay, demonstrated the importance of localized properties of seabeds in determining sound propagation. Other factors that also can si gnificantly affect sound propagation include the orientation of the receivers (the orientation of living animals c ould similarly affect reception), alignments and depths of array components and of functioning guns within the array, and airgun source depth. The depth at which the firing airgun is placed plays a crucial role in the potential for propagation. Increasing source depth consis tently increased the received signal at any specified receiver depth (for example, the depth of the animal) and horiz ontal range. If the

animal is in a shallow-water area and on the botto m, and the airgun is in much deeper water and downslope from the animal, attenuation will gr eatly affect the sound the animal will receive. Based on all of the aforementioned, McCauley et al. (2000) concluded that predicting sound propagation from any specified airgun arra y needs to be done on a case-by-case basis. Bain (2002) found that approxima tely one-third of sound levels measured during seismic surveys varied by 6 dB from expected values. Shadow zones caused sound levels lower than expected, and land was an effective barrier to di rect sound propagation. Cases of levels higher than expected probably were due to upslope enhancement of sound. Long-range propagation through the Strait of Juan de Fuca was better than expected, resulti ng in airgun noise being

53clearly audible at ranges of 60-70 km. This was the longest dist ance at which signal measurement was attempted, and it is possible that the sound was audible at even greater distances. Bain (2002) reports that high frequencies attenuated faster with distance, and low frequencies were filtered out by pr opagation through shallow water.

Tolstoy et al. (2004) compared measured versus modeled noise level radii associated with different seismic arrays in shallow and very d eep water in the Gulf of Mexico and concluded that models may have been underestimati ng noise level radii in shallow water and overestimating those in very deep waters. Richardson et al. (1995a:290-291) summarized: “Underwater sound pulses from air gun arrays and similar sources are often audible many tens of kilometers away .” Transient noise from such a surv ey has been recorded on land seismometer arrays 6,100 km away after tr aveling the deep sound channe l (Okal and Talandier 1986). However, McDonald, Hildebrand, and Webb (1995) suggest that these same sounds may not have been detectable by a whale near the surface in the mid-Pacific because of entrapment in the deep sound channel. During monitoring using passive acoustics in the mid-Atlantic Ocean, Nieukirk et al. (2004) frequently recorded sounds from seismic airguns from locations more than 3,000 km from their array of autonomous hydrophone s moored near the mid-Atlantic Ridge. Trends in the patterns of detection were sim ilar in the two years of monitoring with airguns being detected every 10-20 seconds. Nieuki rk et al. (2004) repor ted that “Although airgun sounds tended to dominate recordings during the summer months, loud whale vocalizations could still be detected during intense airgun activity...The high re ceived level of these impulses on multiple hydrophones made it possible to estimate the location of the ships conducting the airgun surveys .”

Timing of Potential Exposure to Noise and Disturbance from Active Seismic Surveys In the proposed actions under consideration, we a ssume that 2D/3D seismic surveys could occur during the entire open water period in the Chukchi S ea and Beaufort Sea, except as restricted by mitigations. Further, ice conditions within th e Chukchi would be likely to prevent seismic earlier than July 1 of any year.

Open-water 2D/3D seismic surveys in the Beaufo rt Sea Planning Area likely would be feasible only in the months of August, September, and October. Depending on the restrictions usually agreed to in past conflict a voidance agreements for bowhead wh ales, it is likely that 2D/3D seismic surveys will not occur after the bowhead westward migration has occurred, except in areas outside of hunting areas or after hunting for a given Beaufort Sea village has ceased. We assume that steps will be taken to avoid an unmitigable adverse effect on the availability of bowhead whales for take for subsistence, or th at steps will be take n to avoid unreasonable conflict with such activities. Timing to a void effects on subsiste nce takes may amplify disturbance on the whales, since it may concentr ate seismic activity in between hunting activity, both spatially and temporally.

In the Chukchi Sea, depending on ice conditions and conflict avoidance requirements, seismic surveys could not begin until July 1 (unless authorized by NMFS) and end in November. Thus, the total period of seismic surveys is likely to be considerably l onger in the Chukchi Sea than in

the Beaufort Sea. No subsistence take of fin or humpback whales occurs.

54High-Resolution Seismic Surveys High-resolution seismic surveys generally are conducted on lease followi ng a lease sale to evaluate potential shallow hazards and identify seafloor features and resources (e.g., shipwrecks, potential archaeological sites). Vessels used for high-resolution seismic are typically smaller (about 37 to 47 m) than those used for 2D/3D se ismic surveys. Some high-resolution seismic surveys, such as those using airguns, emit loud sounds; but the sounds would not be as loud as sounds from 2D/3D seismic surveys. The sound also would not be likely to propagate as great a
distance as sounds from 2D /3D seismic surveys.

A “typical” high-resolution survey involves a ship towing an ai rgun about 25 m behind the ship and a 600-m streamer cable with a tail buoy. The ship travels at 3-3.5 kn (5.6-6.5 km/h), and the airgun is fired every 7- 8 sec onds (or about every 12.5 m). T ypical surveys cover one lease block, which is 4.8 km on a side.

Potential Effects of High-Resolution Seismic

Because high-resolution seismic surveys use re latively lower energy and sound would be less likely to travel as far as sound from 2D/3D seis mic surveys, these activities are less likely to have significant effects on endangered bowhea d, fin, and humpback whales. Bowheads appear

to continue normal behavior at closer distances to high-resoluti on seismic surveys than to 2D/3D deep penetration seismic surveys. In the study by Richardson, Wells, a nd Wursig (1985), four controlled tests were conducted by firing a single 40 cubic inch (in 3 ) (0.66-metric liter) airgun at a distance of 2-5 kilometers (km) (1.2-3.1 mi) from the whales. Bowheads sometimes continued normal activities (skim feeding, surfacing, diving, and travel) when the airgun began firing 3-5 km (1.86-3.1 mi) away (received noise levels at least 118-133 dB re 1 μPa) root-mean-square (rms). Some bowheads oriented away during an experiment at a range of 2-4.5 km (1.2-2.8 mi) and another experiment at a range of 0.2-1.2 km (0.12-0.75 mi) (received noise levels at least 124-131 and 124-134 dB, respectively). Frequencies of turns, predive flexes, and fluke-out dives were similar with and without airgun noise ; and surfacing and resp iration variables and call rates did not change signifi cantly during the experiments.

Responses of fin and humpback whales to hi gh-resolution surveys ar e uncertain and data specific to these species is lack ing. Because the site-clearance activities are of shorter duration

and have a smaller zone of influence than 2D/3D deep penetration seismic surveys, we believe it unlikely they would result in a biologically significant effect on fin and humpback whales, and responses would be similar to that of bowhead whales. Our primary concern with respect to high-resolution surveys is the poten tial for these activities to a dd to the noise and disturbance footprint of concurrent 2D/3D seismic survey(s) and/or drilling activities, and to cause local effects within a specific area, if large numbers of whales are present. We are specifically concerned about potential effects that could occur if high-resoluti on seismic survey activity were inshore of 2D/3D seismic survey activities or dr illing operations. A concentration of noise- and disturbance-producing factors may keep humpback and fin whales from high-value areas. Humpback and fin whale data for the planning ar eas currently are not su fficient to identify highvalue areas.

552D/3D Seismic Surveys.

Description and Discussion of the Activity Offshore geophysical exploration seismic survey s conducted in the summer, and on-ice seismic surveys conducted in the winter, are other sources of noise in th e arctic marine environment. Airgun arrays are the most common source of seismic survey noise. A typical full-scale array produces a source level of 248-255 dB re 1 μPa -m, zero to peak (Barger and Hamblen 1980; Johnston and Cain 1981). These surveys emit loud sounds, which are pulsed rather than continuous, and can propagate long distances (in some habitats, ve ry long distances) from their source. However, most energy is directed downw ard, and the short duration of each pulse limits the total energy. Received levels within a fe w kilometers typically exceed 160 dB re 1 μPa (Richardson et al. 1995a), depending on wate r depth, bottom type, ice cover, etc.

While the seismic airgun pulses are directed towards the ocean bottom, sound propagates horizontally for several kilomete rs (Greene and Richardson 1988; Hall et al. 1994). In waters 25-50 m deep, sound produced by airguns can be detected 50-75 km away, and these detection ranges can exceed 100 km in deeper water (R ichardson et al. 1995a). Sounds produced by seismic pulses can be detected by mysticetes and odontocetes that are from 10-100 km from the source (Greene and Richardson 1988; Bowles et al. 1994; Richardson et al . 1995a) or potentially

further under some conditions.

Recent 3D seismic surveys in the Chukchi Sea, using a 24 gun array consisting of 3147 c.i., produced sounds up to 160 dB out to a distance of over 8km, while the 120 dB isopleths often

extended over 70 km from the s ource vessel(Funk et al. 2008).

In the Biological Evaluation prepared fo r Beaufort OCS Lease Sale 195 in 2003, MMS concluded that, “Geophysical surveys conducte d in conjunction with proposed Lease Sale 195 are likely to cover much smaller areas to fill in ga ps from earlier seismic surveys. Also, some of the seismic work that may be needed may be conducted when whales are not present in the area.” However, recent interest in 2D/3D seis mic exploration by oil and gas companies in the

Beaufort and Chukchi Seas indicat e this assumption is no longer true. We now expect regular 2D/3D, as well as high-resolution seismic survey activity in Federal waters of the Beaufort Sea over the next 5 years. We expect this level of ac tivity to be greater than that during the period of the previous 5 years (2000-2005). New seismic surv ey activity is expected to be mostly 3D seismic. We still expect that some of the se ismic survey work will be conducted when whales are not present. However, at present, much of the proposed seismic survey work in both the Beaufort Sea and Chukchi Sea Planning Areas is expected to be open water 2D or 3D seismic surveys using streamers.

Potential Effects of 2D/3D Seismic Surveys on Whales Baleen whales generally tend to avoid operating airguns, but avoidance ra dii are quite variable. Whales are often reported to show no overt reactions to pulses fr om large arrays of airguns at distances beyond a few kilometers , even though the airgun pulses remain well above ambient noise levels out to much longer distances. Howe ver, baleen whales exposed to strong noise pulses from airguns often react by deviating from their normal migration route and/or

56interrupting their feeding and moving away. St udies of gray, bowhead, and humpback whales

have determined that received leve ls of pulses in the 160–170 dB re 1 μ Pa rms range seem to

cause obvious avoidance behavior in a substant ial fraction of the animals exposed. In many areas, seismic pulses from large arrays of airguns diminish to those levels at distances of 4.5 to 14.5 km (2.4 to 7.8 n.mi.) from the source. A substa ntial proportion of the baleen whales within those distances may show avoidance or other strong disturbance reactions to the airgun array. Subtle behavioral changes sometimes become evident at somewhat lower received levels, and recent studies have shown that some species of baleen whales, notably bowhead and humpback whales, at times show strong avoidance at received levels lowe r than 160–170 dB re 1 μ Pa rms.

Numerous studies have been conducted on the eff ects of noise from seismic surveys on bowhead whales, but few have been conducted on either hu mpback or fin whales. The results from the studies on bowhead whales have varied, in some cases considerably. Among some of these studies important variables were di fferent. These included the type of seismic survey (2D versus 3D), the location of the study, and the year in which the study was conducted. Ice (and other weather-related factors) also varies among years as does th e use of total av ailable habitat by bowhead whales. Some of the studies employe d different methodologies, some of which have been criticized by peer reviewers and others of which are more wi dely adopted. Because of the importance of the issue of pot ential noise disturbance of bowhead whales, we provide considerable detail on these studies below. However, we preface this section with an observation: In numerous reports regarding wh ale response to sound, it has been shown that multiple factors may be important in the whale’ s response (e.g., McCauley et al., 2000). In some studies, these factors have been shown to include (but may not be limited to): the physical characteristics of the location into which the sound is released and the physical characteristics of

the location where the whale is located at the time the sound is released; the whale’s sex and reproductive condition (e.g., groups w ith or without calves); the behavior of the whale (e.g., migrating or feeding); specific characteristics of the sound (e .g., frequency, duration, whether impulsive or not, etc.), and prior exposure to the sound. Thus, the f act that results from different studies of bowhead response to oil and gas-related sound have va ried is not surprising. The studies involving the response of bowheads to 3D marine streamer seismic surveys are most relevant to evaluating the potenti al effects of the proposed action.

During the 1980’s, the behavior of bowhead wh ales exposed to noise pulses from seismic surveys was observed during the summer in th e Canadian Beaufort Sea and during the fall migration across the Alaskan Beaufort Sea. In general, many of the seismic surveys conducted during the 1980’s were 2D seismic surveys that c overed fairly large areas in deeper waters. Additional studies on seismic surveys were cond ucted in the central Alaskan Beaufort Sea during the fall migration in 1996-1998. These surveys were 3D ocean bottom cable (OBC) seismic surveys that covered fairly small areas in relatively shallow water fairly close to shore. Reeves, Ljungblad, and Clarke (1983) conducted aerial survey s to observe bowhead whale behavior in the presence of activ e seismic vessels. Whales were observed as close as 3 km (1.86 mi) and as far away as 135 km (83.9 mi) from active seismic vessels. A pair of whales observed at a distance of 3 km (1.83 mi) were not m oving while at the surface although the two whales’ heads were in contact. This pair of whales was closer to a shooting seismic vessel than any other whales observed during the study. No obvious response was apparent, but the observation time was brief. (The received level of low-frequency underwater sound from an underwater

57source, generally is lower by 1-7 dB near the surface (depth of 3 m) than at deeper (greater than 9 m) depths (Richardson et al., 1995a). It is pos sible these whales may have been at the surface to avoid the louder noise in deeper water. For the group of 20 whales at a distance of approximately 135 km (83.9 mi), the blow frequenc y per surfacing and time at the surface were greater during the period immedi ately after the seismic vessel be gan shooting than before it began shooting. The authors stated that no majo r changes in whale beha vior (such as flight reactions) were observed that coul d unequivocally be interpreted as responses to seismic noise. They noted a possible exception of “huddling be havior”, which they thought may have been caused by the onset of seismic sounds. The authors concluded that althou gh their results suggest some changes in behavior related to seismic sounds, the possibility that unquantified factors

could be correlative dictates ca ution in attempting to establish causative explanations from the preliminary findings.

Ljungblad et al. (1985) also repor ted findings from early tests of bowhead reacti ons to active seismic vessels in the Beaufort Sea. However, methodological problems with this early study preclude us from drawing conclu sions about probable bowhead r eactions based on its findings.

A subcommittee of the Scientific Committee of the IWC previously reviewed the data from this study and some members were cr itical of the methodology and an alysis of the results. Comments included reference to: the small sample size; inconsistencies between the data and the conclusions; lack of documentati on of calibration of s ound monitoring; and po ssible interference

from other active seismic vessels in the vicin ity. The subcommittee acknowledged the difficulty of performing experiments of this kind, particular ly in the absence of a control environment free

of industrial noise. The subcommittee recommende d that additional research taking into account the concerns expressed above be undertaken, and th at the 1984 experimental results be subjected to rigorous reanalysis, before it could be used to draw any conclusions about the effects of seismic activity on this species (IWC 1987).

In the May 25, 2001 Biological Opinion for Federa l Oil and Gas Leasing and Exploration by the

MMS within the Alaskan Beaufort Sea and its effects on the endangered bowhead whale, NMFS (2001:20) noted that early tests of bowhead reac tions to active seismic vessels by Ljungblad et al. (1985):

...were not conducted under controll ed conditions (i.e., other noise sources were operating at the time), and approaches at greater ranges were not conducted, so result s cannot be used to determine the range at which the whales first begin to respond to seismic activity.

In Fraker et al. (1985), an ac tive seismic vessel traveled towa rd a group of bowheads from a distance of 19 km (11.8 mi) to a distance of 13 km (8.18 mi). The whales did not appear to alter their general activities. Most wh ales surfaced and dove repeatedly and appeared to be feeding in the water column. During their repeated surfacing and dives, they moved slowly to the southeast (in the same direction as seismic-ve ssel travel) and then to the northwest (in the opposite direction of seismic-vessel travel). The study first stated th at a weak avoidance reaction may have occurred but then stated ther e is no proof that the whales were avoiding the vessel. The net movement was about 3 km (1.86 mi). The study found no evidence of differences in behavior in the presence and absen ce of seismic noise, but noted that observations

were limited.

58In another study (Richardson, Wells, and Wurs ig 1985) involving a full-scale seismic vessel with a 47-L airgun array (estimated source le vel 245-252 dB re 1 μPa), bowheads began to orient away from the approaching ship when its airguns began to fire from 7.5 km (4.7 mi) away. This airgun array had about 30 airguns, each with a volume of 80-125 in 3 . The Mariner had been shooting seismic about 10 km to the west of a group of six whales. Prior to the start of the experimental seismic period, the whales were surfacing and diving and moving at slow to medium speed while at the surface. The vessel c eased shooting and moved within 7.5 km of the whales and began firing the airgun array while approaching the whales. The study reported no conspicuous change in behavior when the Mariner resumed shooting at 7.5 km away. The bowheads continued to surface and dive, moving at slow to medium speeds. The received level was estimated at 134-138 dB at 7 km (4.35 mi). Some near-bottom feeding (evidenced by mud being brought to the surface) continued until the vessel was 3 km (1.86 mi) away. The closest point of approach to any whale was approxima tely 1.5 km (0.93 mi), with the received level probably well over 160 dB. When the seismic ve ssel was within 1.5 km of whales at the original location, at leas t two of the whales were observed to have moved about 2 km to the south of the original lo cation. The movements of the whales, at least while they were at the surface, were at the usual slow to moderate sp eeds. The study reported no conspicuous changes

in behavior when the Mariner ceased shooting at 6 km beyond the whales. The bowheads were still surfacing and diving and moving at slow to medium sp eed. The most notable change in behavior apparently involved the cessation of feeding when th e vessel was 3 km away. The whales began feeding agai n about 40 minutes after the seismic noise ceased.

While conducting a monitoring program around a drilling operation, Koski and Johnson (1987)

noted that the call rate of a single observed bowhead whale increased after a seismic operation had ceased. During the 6.8 hours of observati on, the whale was within 23-27 km (14.3-16.8 mi) from the drillship. A seismic vessel was repor ted to be from 120-135 km (74.58-83.9 mi) from the sonobuoy; the two loudest calls received were determined to be approximately 7 km (4.35 mi) and 9 km (5.6 mi) from the sonobuoy, with rece ived levels of 119 and 118 dB, respectively. Approximate signal-to-noi se ratios were 24 and 22 dB, respectively. No information is provided regarding the exact distance the whale was from the operating seismic vessel. The increase in

call rate was noted within 25 minutes after seismic noise ceased. It also needs to be noted that there were few, if any, calls heard during the 2 hours prio r to the start of seismic operations, so it

is unclear whether the increase in call rate relates to cessation of seismic noise, the presence of the operating drillship, the combination of both activ ities, or some other f actor that occurred in the late afternoon. During this sa me study a subgroup of four to seven whales within a larger group (15-20 whales) was noted moving rapidly aw ay from an approaching seismic vessel at a distance of 22-24 km (13.7-14.9 mi). The received level of seismic pulses was 137 dB at 19 km (11.8 mi) from the sonobuoy and 22 km from the whales. The surfacing and diving were unusually brief, and there were unusually few blows per surfacing. No information was available regarding the time required for thes e whales to return to normal behavior.

The North Slope Borough (NSB) believes that ma ny studies were different from the real-world situation, and various limitations have been pointed out. Most studies did not involve actively migrating whales; and those whales were being a pproached by the seismic ships whereas in the real world, the fall migrating whales are actively moving to the west and they are approaching a distant seismic boat that is firing. The MMS ha s noted that many studies were observational and

59involved opportunistic sightings of whales in the vicinity of seismic operations. The studies were not designed to show whether more subtle reactions are occurring that can displace the migration corridor, so no definitive conclusions can be drawn from them on whether or not the overall fall migration is di splaced by seismic activity.

Based on early data, Richardson and Malme (1993) concluded that collectively, scientific

studies have shown that most bowheads usua lly show strong avoidance response when an operating seismic vessel approaches within 6-8 km (3.8-5.0 mi). Strong avoidance occurs when

received levels of seismic noise are 150-180 dB re 1 μPa (Richardson and Malme, 1993). Strong pulses of seismic noise often are detect able 25-50 km (15.5-31 mi) from seismic vessels, but in early studies, bowheads exposed to seismi c sounds from vessels more than about 7.5 km (4.7 mi) away rarely showed avoidance. Seis mic pulses can be detectable 100 km (62.2 mi) or more away. Bowheads also may show specific beha vioral changes, such as reduced surfacing; reduced dive durations; changes in respiration rates, including fewer blows per surfacing, and longer intervals between successive blows; and they may tempor arily change their individual swimming paths. The authors noted that surfacin g, respiration, and dive cycles may be altered

in the same manner as those of whales closer to the vessels. Bowhead surface-respiration-dive characteristics appeared to r ecover to pre-exposure levels w ithin 30-60 minutes following the cessation of the seismic activity.

Inupiat whalers suggested that the fall bowhead migration tended to be farther offshore when

there was abundant seismic work off northern Al aska. Aerial surveys have been conducted

since 1979 to determine the distribution and abunda nce of bowhead whales in the Beaufort Sea during their fall migration. These surveys have been used for comparing the axis of the bowhead whale migration between years. Su rvey data from 1982-1987 were examined to

determine whether industrial activ ity was resulting in displaceme nt of bowhead whales farther offshore (Ljungblad et al. 1988). It was determined that a good indicator of annual shifts in bowhead distribution could be obtained by analyz ing the distance of random bowhead sightings from shore (Zeh, as cited in Ljungblad et al. 1988 ). An analysis of the distance of random bowhead sightings from shore (a total of 60 bowhead sightings) was conducted, but no significant differences were detected in the bowhead migratory route between years. The axis of the bowhead migratory route near Barrow wa s found to fall between 18 and 30 km (7.76 and 18.6 mi) from shore. Although the analysis invol ved a relatively small sample size, these observations provide some insight into migratio n patterns during these y ears. The NSB, in a letter dated July 25, 1997, questioned the sample size and the precision of the Ljungblad et al. (1988) report to determine whether or not a disp lacement of fall migrati ng whales had occurred and how big a displacement would have to be before it could be detected. Using larger sample sizes (for which confidence intervals were calcu lated) obtained over a larger study area, the aerial survey project found many between-year (1982-1996) differences in the median water depth at whale sightings that were highly signi ficant (P less than 0.05) (Treacy 1997). Median depths ranged between 18 m (59 ft) in 1989 and 347 m (1,138 ft) in 1983 , with an overall cumulative depth of 37 m (121 ft, confidence interv al = 37-38 m). The aerial survey project has reported a potential association between water de pth of the bowhead migration and general ice severity, especially in 1983, when severe ice cover may have forced the axis of the migration into waters 347 m (1,138 ft) deep. To address s hort-term bowhead whale displacement within a given year from site-specific industrial noise , MMS and NMFS require in dustry to conduct site60specific monitoring programs when industrial activ ity occurs in the Beau fort Sea Planning Area during fall bowhead migrations.

Since 1996, many of the open water seismic survey s in State of Alaska waters and adjacent

nearshore Federal waters of the central Alaskan Beaufort Sea were ocean-bottom cable surveys. These surveys were 3D seismic programs. The area to be surveyed is divided into patches, each patch being approximately 5.9 by 4.0 km in size. Within each patch, several receiving cables are laid parallel to eachother on the seafloor. Seismic data are acquired by towing the airguns along a series of source lines oriented perpendicula r to the receiving cables. While seismic-data acquisition is ongoing on one patch, vessels are deploying cable on the next patch to be surveyed and/or retrieving cables from a patch where se ismic surveys have been completed. Airgun arrays have varied in size each year from 1996-1998 with the smallest, a 560 in 3 array with 8 airguns, and the largest, a 1,500 in 3 array with 16 airguns. A marine mammal and acoustical monitoring program was conducted in conjuncti on with the seismic program each year in accordance with provisions of the NMFS Incident al Harassment Authorization. Based on 1996- 1998 data, there was little or no evidence that bowhead headings, gene ral activities, or swimming speeds were affected by seismic e xploration. Bowheads approaching from the northeast and east showed similar headings at ti mes with and without se ismic operations. Miller et al. (1999) stated that the lack of any statistically significant differences in headings should be interpreted cautiously. Changes in headings mu st have occurred given the avoidance by most bowheads of the area within 20 or even 30 km of active seismic operations. Miller et al. (1999) noted that the distance at which deflection began cannot be determined precisely, but they stated that considering times with operations on offshor e patches, deflection may have begun about 35 km to the east. However, some bowheads approa ched within 19-21 km of the airguns when they were operating on the offshore patches. It app ears that in 1998, the offshore deflection might have persisted for at least 40-50 km west of th e area of seismic operations. In contrast, during 1996-1997, there were several sightings in areas 25 -40 km west of the most recent shotpoint, indicating the deflection in 1996-1997, may not have persiste d as far to the west.

LGL Ltd.; Environmental Research Assocs., Inc. ; and Greeneridge Sciences Inc. conducted a marine mammal monitoring program for a seis mic survey near the Northstar Development Project in 1996 (Miller et al ., 1997). The marine mammal mon itoring program was continued for subsequent seismic surveys in nearshor e waters of the Beaufort Sea in 1997 and 1998 (Miller, Elliot, and Richardson, 1998; Miller et al., 1999). Details of th ese studies are provided in the Beaufort Sea multiple-sale final EIS. These studies indicated that the bowhead whalemigration corridor in th e central Alaskan Beaufort Sea duri ng 1998 was similar to the corridor in many prior years, although not 1997. In 1997, nearly all bowheads sighted were in relatively

nearshore waters. The results of the 1996-1998 studies indicated a tendency for the general bowhead whale-migration corridor to be farther offshore on days with seismic airguns operating compared to days without seismic airguns ope rating, although the distances of bowheads from shore during airgun operations overlapped with t hose in the absence of airgun operations. Aerial-survey results indicated that bowheads tended to avoid the area around the operating source, perhaps to a radius of about 20-30 km. Sighting rates within a radius of 20 km of seismic operations were significantly lower dur ing seismic operations than when no seismic operations were happening. With in 12-24 hours after seismic operations ended, the sighting rate within 20 km was similar to the sighting rate beyond 20 km. There was little or no evidence of

61differences in headings, general activities, a nd swimming speeds of bowheads with and without seismic operations. Overall, the 1996-1998 result s show that most bowheads avoided the area within about 20-30 km of the operating airguns . Within 12-24 hours after seismic operations ended, the sighting rate within 20 km was similar to the sighting rate beyond 20 km.

The observed 20-30 km area of avoidance is a larger avoidance radius than documented by previous scientific studies in the 1980s and sm aller than the 30 mi suggested by subsistence whalers, based on their experien ce with the types of seismic ope rations that occurred in the Beaufort Sea before 1996 (Richardson 2000). Th e seismic activities in the 1980s were 2D in deeper water. Recent seismic activities were 3D OBC concentrated in shallow water. Based on recordings of bowhead whale calls ma de during these same studies, Greene et al. (1999), summarized that results for the 3 years of study indicated that: (1) bowhead whales call frequently during the autumn migration through the study area; (2) calling continued at times when whales were exposed to airgun pulses; and (3) call-detection ra tes at some locations differed significantly when airguns were detectab le versus not detectable. However, there was no significant tendency for the call- detection rate to change in a consistent way at times when airguns started or stopped.

Richardson provided a brief comparison between observations from seismic studies conducted in the 1980s and the 1996 seismic survey at the Arctic Seismic Synthesis Workshop in Barrow (USDOI, MMS 1997). Observations from earlier seismic studies during the summer and early

autumn show that most bowhead whales interru pt their previous activ ities and swim strongly away when a seismic ship approaches within about 7.5-8 km. At the distances where this strong avoidance occurs, received leve ls of seismic pulses typically are high, about 150-180 dB re 1 μPa. The surfacing, respiration, a nd dive cycles of bowheads enga ged in strong avoidance also change in a consistent pattern involving unus ually short surfacing and diving and unusually few blows per surfacing. These avoi dance and behavioral effects among bowheads close to seismic vessels are strong, reasonably c onsistent, and relatively easy to document. Less consistent and weaker disturbance effects proba bly extend to longer distances a nd lower received sound levels

at least some of the time. Bowheads often tolera te much seismic noise and, at least in summer,

continue to use areas where seis mic exploration is common. Ho wever, at least one case of strong avoidance has been reported as far as 24 km from an approaching seismic boat (Koski and Johnson 1987) and, as noted above, the aerial survey data (Miller et al. 1999) indicated that bowheads tended to avoid the area around the operating source, perh aps to a radius of about 20- 30 km. Richardson noted that many of the observations involved bowheads that were not actively migrating. Actively migrating bowheads may react somewhat differently than bowheads engaged in feeding or socializing. Migrating bowheads, for instance, may react by deflecting their migration corrido r away from the seismic vessel. Monitoring of the bowhead migration past a nearshore seismic operation in September 1996 provided evidence consistent with the possibility that the closest whales may have been displaced several miles seaward during periods with seismic activity.

With respect to these studies conducted in the Beaufort Sea from 1996-1998, the peer-review group at the Arctic Open-Water Noise Peer Re view Workshop in Seattle from June 5-6, 2001, prepared a summary statement supporting the met hods and results reported in Richardson (1999) concerning avoidance of seismic sounds by bowhead whales:

62Monitoring studies of 3-D seismic expl oration (8-16 airguns totaling 560-1,500 in 3 ) in the nearshore Beaufort Sea during 1996-1998 have dem onstrated that nearly all bowhead whales will avoid an area within 20 km of an active seismic source, while deflection may begin at distances up to 35 km. Sound levels received by bowhead whales at 20 km ranged from 117- 135 dB re 1 μPa rms and 107-126 dB re 1 μPa rms at 30 km. The received sound levels at 20-30 km are considerably lower levels than have previously been shown to elicit avoidance in bowhead or other baleen whales exposed to seismic pulses

.

A recent study in Canada provides recent inform ation on the behavioral response of bowhead whales in feeding areas to seismic surveys (M iller and Davis, 2002). During the late summer and autumn of 2001, Anderson Resources Ltd. c onducted an open-water seismic exploration program offshore of the Mackenzie Delta in the Ca nadian Beaufort Sea. The program consisted of streamer seismic surveys and associated bathymetric surveys conducted off the Mackenzie Delta. The bathymetric surveys were conducted by two medium-sized ve ssels equipped with side-scan sonar and single-beam echo sounders. The seismic vessel was the Geco Snapper . The

acoustic sources used in the se ismic operations were two 2,250 in 3 arrays of 24 sleeve-type airguns. Each 2,250 in 3 airgun array was comprised of 24 ai rguns with volumes ranging from

40-150 in 3 . The two airgun arrays fired alternately ev ery 8 seconds along the survey lines. The airgun arrays were operated at a depth of 5 m be low the water surface. Water depths within the surveyed areas ranged from 6-31 m and averaged 13 m (Miller, 2002). Because marine seismic projects using airgun arra ys emit strong sounds into the water and have the poten tial to affect marine mammals, there was concern about the ac oustic disturbance of marine mammals and the potential effects on the accessibil ity of marine mammals to subs istence hunters. Although there are no prescribed marine mammal and acousti c monitoring requirements for marine seismic programs in the Canadian Beaufort Sea, it was decided that monitoring and mitigation measures

in the Canadian Beaufort Sea should be as ri gorous as those designed and implemented for marine seismic programs conducted in the Alas kan Beaufort Sea in recent years. The monitoring program consisted of three primary components: acoustic measurements, vesselbased observations, and aerial surveys. The NMFS-recommended criterion that exposure of whales to impulse sound not exceed 180 dB re 1 Pa rms (65 FR 16374) was adopted as a mitigation standard for this monitoring program . Estimates of sound-propagation loss from the airgun array were used to determine the desi gnated 1,000-m safety radius for whales (the

estimated zone within which received levels of seismic noise were 180 dB re 1μPa rms or higher).

Aerial and vessel-based surveys confirmed the presence of substantia l numbers of bowheads offshore of the Mackenzie Delta from late Augus t until mid-September. The distribution of bowheads in the study area was t ypical of patterns observed in other years and suggests that there were good feeding opportunitie s for bowheads in these waters during that period. A total

of 262 bowheads were observed from the seismic vessel Geco Snapper (Moulton, Miller, and Serrano, 2002). Sighting rates during daylight hours were higher when no airguns were operating than during periods with airguns ope rating. During the period when bowheads were most abundant in the study ar ea (August 23-September 19), the bowhead sighting rate during periods with no seismic (0.85 bowheads/hour) was a bout twice as high as that recorded during periods with seismic (0.40 bowh eads/h) or all seismi c operations combined (0.44 bowheads/h). Average sighting distances from the vessel were significantly (P <0.001) lower during no

63airguns (a mean radial distance of 1,368 m) versus line-seismic pe riods (a mean radial distance of 1,957 m). The observed difference in sighting ra tes and the significant difference in sighting distances suggest that bowheads did avoid close approach to the area of seismic operations. However, the still substantial number of sightings during seismic periods and the relatively short (600 m) but significant difference in sighting distances suggests that the avoidance may have been localized and relatively small in nature. At a minimum, the distance by which bowheads avoided seismic operations was on the order of 600 m greater than the average distance by which they avoided general vessel operations. The lower sighting rates recorded during seismic operations suggest that some bow heads avoided the seismic operati ons by larger distances and, thereby, stayed out of visual range of the marine mammal observers on the Geco Snapper

.

In this study, a total of 275 bowh ead whale sightings were recorded during aerial transects with good lighting conditions (Holst et al. 2002). Bowheads were sighted at similar rates with and without seismic, although the no feeding-seis mic sample was too small for meaningful comparisons. Bowheads were seen regularly within 20 km of the operations area at times influenced by airgun pulses. Of 169 transect sightings in good condi tions, 30 sightings were

seen within 20 km of the air gun operations at distances of 5.3- 19.9 km. The aerial surveys were

unable to document bowhead avoidance of the se ismic operations area. The area of avoidance around the seismic operations area was apparently too small to be evident from the broadscale aerial surveys that were flown, especially consid ering the small amount of surveying done when seismic was not being conducted. General activ ities of bowheads during times when seismic operations were conducted were sim ilar to times without seismic.

The bowheads that surfaced closest to the ve ssel (323-614 m) would have been exposed to sound levels of about 180 dB re 1 μPa rms before the immediate shutdown of the array (Miller et al. 2002). There were seve n shutdowns of the airgun array in response to sightings of

bowheads within 1 km of the seismic vessel. Bowheads at the average vessel-based sighting distance (1,957 m) during line seismic would have been exposed to sound levels of about 170 dB re 1 μPa rms. The many aerial sightings of bowheads at distances from the vessel ranging from 5.3-19.9 km would have been exposed to sound levels ranging from approximately 150- 130 dB re 1 μPa rms, respectively.

The results from the study in summer 2001 are ma rkedly different from those obtained during similar studies during the autu mn migration of bowheads thr ough the Alaskan Beaufort Sea (Miller et al. 2002). For example, during th e Alaskan studies only 1 bowhead whale was observed from the seismic vessel(s) during six seasons (1996-2001) of vessel-based observations compared with 262 seen from the Geco Snapper in 2001. The zone of avoidance for bowhead whales around the airgun operations in 2001 wa s clearly much smaller (~2 km) than that observed for migrating bowhead whales in recent autumn studies in Alaskan waters (up to 20-30 km). Davis (1987) concluded that migrating bowheads during the fall migration may be more

sensitive to industrial disturbance than bowh eads on their summering grounds, where they may be engaged in feeding activities.

Inupiat subsistence whalers have stated that industrial noise, es pecially noise due to seismic exploration, has displaced the fa ll bowhead migration seaward and, thereby, is interfering with the subsistence hunt at Barrow (Ahmaogak 1989). Whalers have report ed reaction distances,

64where whales begin to divert from their migratory path, on the order of 10 mi (T. Albert cited in USDOI, MMS 1995) to 35 mi (F. Kanayurak in USDOI, MMS 1997. Kanayurak stated that the bowheads “...are displaced from their normal migratory path by as much as 30 miles .” Also at the March 1997 workshop, Mr. Roxy Oyagak, Jr., a Nuiqsut whaling captain, stated in written testimony: “Based on the industrial activity, there is an unmitigable adverse impact on the village of Nuiqsut on subsistence whaling. i.e., 1) by causing the whales to abandon the hunting area ...and 3) placing physical barriers between th e subsistence whalers and marine mammals, including altering the normal bow head whale migration route.”

Data available from MMS’ BWASP surveys over about a 27 year period indicate that, at least during the primary open water period during the autumn (when open water seismic activities are most likely to occur), there are areas where bow heads are much more likely to be encountered and where aggregations, including feeding aggrega tions and/or aggregati ons with large numbers of females and calves, are more likely to occur in the Beaufort . Such areas include the areas

north of Dease Inlet to Smith Ba y, northeast of Smith Bay, and No rtheast of Cape Halkett, as well as areas near Brownlow Point. Such aggr egations have been observed in multiple years during BWASP surveys. However, in some year s no large aggregations of bowheads were seen anywhere within the study area. In their Biological Evaluation, the MMS voiced particular concern for the potential for seismic to impact si gnificant life history stages of bowhead whales. If 2D/3D seismic surveys occurred in these areas when large aggregations were present, and particularly if multiple 2D/3D seismic survey s occurred concurrently in these areas, MMS

concluded either hundreds of whales could be ex cluded (through avoidance) from a large area for a relatively long portion of the season, or many more individuals would likely avoid the area as they sequentially came in to use the area.

We are aware that the extent of avoidance will vary both due to the ac tual noise level radii around each seismic vessel, the context in which it is heard, and the motivation of the animal to stay within the area. It also may vary de pending on the age, and most likely, the sex and reproductive status of the whale. It may be related to whether subsistence hunting has begun and/or is ongoing. Because the ar eas where large aggregations of whales have been observed during the autumn also are areas used, at least in some years, for feeding, it may be that the

whales would show avoidance more similar to that observed in studies of whales on their summer feeding grounds. However, as noted ab ove, it is not clear that reduced avoidance should be interpreted as a reduction in impact. It may be that bowheads are so highly motivated to stay on a feeding ground that th ey remain at noise levels that could, with long term exposure,

cause adverse effects.

Seismic activity should have little effect on z ooplankton. Bowheads feed on concentrations of zooplankton. Zooplanktons that are very close to the seismic source may react to the shock wave, but little or no mortality is expected (LGL Ltd. 2001). A reaction by zooplankton to a seismic impulse would be relevant only if it caus ed a concentration of z ooplankton to scatter. Pressure changes of sufficient magnitude to cau se zooplankton to sca tter probably would occur only if they were very close to the source. Impacts on zooplankt on behavior are predicted to be negligible and would have negligible effects on feeding bowheads (LGL Ltd. 2001).

65Fin and humpback whales feed on euphausiids (k rill) and small schooling fish. Fish prey species in the North Pacific include Pacific herring ( Clupea harengus pallasi ), capelin ( Mallotus

villosus ), juvenile walleye pollock ( Theragra chalcogramma ), and sand lance ( Ammodytes hexapterus ). Humpback whales are also known to feed on eulachon, Atka mackerel, Pacific cod, saffron cod, arctic cod, juvenile salmon, and rockfish (NMFS 2005).

Fish species may react to seismic activity. Fish are able to detect and respond to a wide variety of sounds. Species differ in the range of fre quencies, or bandwidth, a nd in the threshold sound pressure levels they are able to detect. Many be havioral and physiological investigations of fish hearing show that a number of species, and perhaps all, have the same basic acoustic capabilities as other vertebrates, including mammals (Poppe r et al. 2003, Ladich and Popper 2004). Herring are hearing specialists, their greater hearing capab ility is due to speciali zed extensions of the swim bladder that enters the cranial capsule a nd lies close to the inner ear (Moyle and Cech 1988). This adaptation allows herring to dete ct and respond to signals up to 4000 Hz with

thresholds that are 20dB lower than fish with general hearing capability and is thought important for schooling behavior and dete cting predators and other hazards (Whitehead 1985). This sensitive hearing capability also makes herr ing more vulnerable to interference from anthropogenic noise sources due to its increase d dependence on sound detection as a means of avoiding predation (NMFS 2005). In this case, it is reasonable th at impacts to prey would be negligible unless prey were very close to the source of the seismic activity. Impacts on feeding humpbacks or fin whales would also be expected to be minimal given their limited distribution

in the Arctic environment.

Various vessels are necessary to support se ismic work, and may impact bowhead, humpback, and fin whales. Bowheads react to the approach of vessels at greater distances than they react to

most other industrial activiti es. According to Richardson and Malme (1993), most bowheads begin to swim rapidly away when vessels approach rapidly and directly. This avoidance may be

related to the fact that bowheads have been comm ercially hunted within the lifetimes of some

individuals within the population and they continue to be hunted for subsistence throughout many parts of their range. Avoidance usually be gins when a rapidly appr oaching vessel is 1-4 km (0.62-2.5 mi) away. A few whales may react at distances from 5-7 km (3-4 mi), and a few whales may not react until the vessel is less than 1 km (less than 0.62 mi) away. Received noise levels as low as 84 dB re 1 μPa (rms) or 6 dB above ambient may elicit strong avoidance of an approaching vessel at a distance of 4 km (2.5 mi) (Richardson and Malme, 1993).

In the Canadian Beaufort Sea, bowheads observed in vessel-disturbance experiments began to orient away from an oncoming vessel at a range of 2-4 km (1.2-2.5 mi) and to move away at increased speeds when approached closer than 2 km (1.2 mi) (Richardson and Malme 1993). Vessel disturbance during these experimental conditions temporarily disrupted activities and sometimes disrupted social groups, when groups of whales scattered as a vessel approached. Reactions to slow-moving vessels , especially if they do not approach directly, are much less

dramatic. Bowheads often are more tolerant of ve ssels moving slowly or in directions other than toward the whales. Fleeing from a vessel ge nerally stopped within minutes after the vessel passed, but scattering may persist for a longer period

. After some disturbance incidents, at least

some bowheads returned to th eir original locations (Richa rdson and Malme 1993). Some whales may exhibit subtle change s in their surfacing and blow cycles, while others appear to be

66unaffected. Bowheads actively engaged in social interactions or mating may be less responsive

to vessels.

Seismic vessel support activities may also imp act humpback and fin whales. Research has suggested that noise may cause humpback whales to avoid or leave feeding or nursery areas (Jurasz and Jurasz 1979). Other research has suggested that humpback whales may become

habituated to vessel traffic and its associated noise. Still other researchers suggest that humpback whales may become more vulnerable to vessel strikes once they habituate to vessel traffic (Swingle et al. 1993, Wiley et al. 1995) . While measurable startle responses might diminish with time, this does not necessarily i ndicate that a negative impact has not occurred. Vessels could still cause physiologi cal stress impacts or could disr upt prey aggregations forcing whales to spend a greater amount of time and energy foraging.

Baker and Herman (1989) conducted controlled studies on the impact of vessel traffic on humpback whales in southeast Alaska. They examined responses to obtrusive, unobtrusive, and “passby” conditions created by diffe rent vessel classes. In that study, respiratory behaviors were the most sensitive indicators of response to a vessel. The obtrusive condition resulted in a striking increase in the frequency of blows when the whale was near the surface and an increase in the longest submergence observed. The e ffects declined as the activity of the vessel moderated during the unobtrusive and “passby” conditions. Within the 400 m range of influence, vessel operations accounted for 27.5% of th e variance in the blow intervals of whales. The study also noted the tendency of humpback whales to orient in the direction of a vessel as it approached, and then to turn away at a perpendi cular as the vessel reached its closest point of approach. The percentage of whale movement devoted to avoidance be havior increased from

15% at a distance from the vessel of 4000 m to 27% at a distance from the vessel of 1000 m.

Other studies on humpback whales in their winter ing grounds indicate some changes in behavior in response to vessels. Corkeron (1995) showed th at animals dove more often in the presence of

vessels when the vessels were w ithin 300 m of the animal. Moth er-calf pairs almost never dove when vessels were absent yet did so when vesse ls were present, spe nding significantly more time submerged or traveling and potentially incurring energetic costs. For non-calf pods, the rates at which certain behaviors (e.g., roll, l unge, fluke and flipper activity, and breaching) occurred were significantly different when vessels were present than when vessels were absent. Bauer et al. (1993) found that smaller humpback whale pods with calves were more affected by vessel activity than were larger pods without calves.

Although it is difficult to quantify the behavioral effect of vessel noise impacts on humpback whales, based on existing information we can assume that individual humpback whales may alter their behavior in the presence of the vessels. Whales may leave the action area if sufficiently disturbed. It is more likely they will leave an area if not actively involved in feeding at the time of the disturbance. Displacemen t may adversely affect individual animals by requiring additional energy investment to forage elsewhere, and thus may translate into the reduced fitness of an individual. However, gi ven that a relatively small number of humpback whales appear to use the Arctic environment at present, the effects of alterations in behavior, temporary disruption, or displacem ent are not expected to impact a significant portion of the population such that the recovery or survival of the species would be compromised. One can

67infer similar behavioral reactions for fin whales, as baleen whales closely related to humpbacks. Likewise, the effects of vessel noise and approach are likely to be minimal on the fin whale population given the limited number of animals t hought to be regularly present in the action

area.

Bowhead, fin and humpback whales could encounter noise and disturbance from multiple seismic vessels and multiple support vessels as they migrate and feed in the Beaufort and

Chukchi Seas. The likelihood of encounter for fi n and humpback whales is considered to be low; however, if an encounter were to occur, the impacts may be expected to be similar to those involving bowheads. The significance of such en counters is expected to depend on the area in which the vessels are transiting, the total number of vessels in the area, the presence of other vessels (see cumulative effects section), and vari ables already identified regarding the number, behavior, age, sex and reproductive condition of the whales. Depending on ice conditions, it is likely that vessels actively invol ved in ice management or moving from one site to another would be more disturbing to whal es than vessels idling or mainta ining their position. In either case, bowheads, fins and humpbacks probably woul d adjust their individu al swimming paths to avoid approaching within several kilometers of vessels attending a dr illing unit and probably would move away from vessels that approached within a few kilometers. Vessel activities associated with exploration are not expected to disrupt the bowh ead migration. Small

deflections in individual bowh ead-swimming paths and a reducti on in use of possible bowheadfeeding areas near exploration units may result in adverse effects on the species. During their spring migration (April through J une), bowheads likely would encounter few, if any, vessels along their migration route, because ice at this time of year typically would be too thick for seismic-survey ships and supply vessels to oper ate in. Because MMS is not allowing seismic shooting in the spring lead system until July 1 unless authorized by NMFS, we do not expect seismic survey vessel interaction to be an impor tant source of disturba nce during the northward migration. Given that fin and humpback whales , to our knowledge, do not migrate through any of these areas and are most likely infrequent vi sitors, we do not expect seismic survey vessel interaction to be a source of disturbance for these two species.

In addition to acting as a source of noise and dist urbance, marine vessels could potentially strike whales, causing injury or death. As noted in th e baseline section of this evaluation, available

information indicates that current rates of vesse l strikes of fin, humpback, and bowhead whales in these waters are low. At present, availabl e data do not indicate thatstrikes by oil and gasrelated vessels will become an important sour ce of injury or mortality in the Chukchi or Beaufort Sea Planning Areas. Risk of strikes w ould increase as vessel traffic in whale habitat

increases.

If seismic survey vessels are attended by icebreakers involving active ice management,

additional disturbance and noise wi ll be introduced by the noise of the icebreaker. There are no observations of bowhead, fin or humpback reacti ons to icebreakers breaking ice. Response distances would vary, depending on icebreaker activities and sound-pr opagation conditions. Based on models, bowhead whales likely w ould respond to the sound of the attending

icebreakers at distances of 2-25 km (1.24-15.53 mi) from the icebreakers (Miles, Malme, and Richardson 1987). Zones of responsiveness for intermittent sounds, such as an icebreaker pushing ice have not been studied. The study not ed above predicts that roughly half of the

68bowhead whales show avoidance response to an icebreaker underway in open water at a range of 2-12 km (1.25-7.46 mi) when the sound-to-noise ra tio is 30 dB. The study also predicts that roughly half of the bowhead whales would show avoidance response to an icebreaker pushing ice at a range of 4.6-20 km (2.86-12.4 mi) when th e sound-to-noise ratio is 30 dB. Richardson et al. (1995b) found that bowheads migrating in the nearshore lead often tolerated exposure to projected icebreaker sounds at received levels up to 20 dB or more above the natural ambient noise levels at corresponding fre quencies. The source level of an actual icebreaker is much higher than that of the project ors (projecting recorded sound) used in this study (median difference 34 dB over the frequency range 40-6,3 00 Hz). Over the two-season period (1991 and 1994) when icebreaker playbacks were attempted, an estimated 93 bowheads (80 groups) were seen near the ice camp when the projectors were transmitting icebreaker sounds into the water, and approximately 158 bowheads (116 groups) were s een near there during quiet periods. Some bowheads diverted from their course when expos ed to levels of proj ected icebreaker sound greater than 20 dB above the na tural ambient noise level in th e one-third octave band of the strongest icebreaker noise. However, not all bow heads diverted at that sound-to-noise ratio, and a minority of whales apparently diverted at a lower sound-to-noise ratio. The study concluded that exposure to a single playb ack of variable icebreaker sou nds can cause statistically but probably not biologically significan t effects on movements and behavi or of migrating whales in the lead system during the spring migration eas t of Point Barrow. The study indicated the predicted response distances for bowheads ar ound an actual icebreak er would be highly variable; however, for typical traveling bowheads, detectab le effects on movements and behavior are predicted to extend commonly out to radii of 10-30 km (6.2-18.6 mi). It should be noted that these predictions were based on reactions of whales to playbacks of icebreaker sounds in a lead system during the spring migration and are subject to a number of qualifications. The predicted typical radius of responsiv eness around an icebreaker like the Robert Lemeur is quite variable, because propagation conditions and ambien t noise vary with time and with location. In addition, icebreakers vary widely in e ngine power and noise output, with the Robert Lemeur being a relatively low-powered i cebreaker. Furthermore, the r eaction thresholds of individual whales vary by at least 10 dB around the typical threshold, with commensurate variability in predicted reaction radius.

While conducting aerial surveys over the Kuvlum drilling location, Brewer et al. (1993) showed

that bowhead whales were observed within abou t 30 km (18.6 mi) north of the drilling location. The closest observed position for a bowhead wh ale detected during the aerial surveys was approximately 23 km (14.3 mi) from the project icebreakers. Th e drilling rig was not operating on that day, but all three icebreak ers had been actively managing i ce periodically during the day. The study did not indicate what the whale’s behavi or was, but it did not appear to be avoiding

the icebreakers. Three whales we re sighted that day, and all thr ee appeared to be moving to the northwest along the normal migration route at speeds of 2.4-3.4 km/h (1.5-2.1 mi/h). Bowhead whale call rates peaked when whales were about 32 km (19.9 mi) from the industrial activity. There was moderate to heavy ice conditions throughout the monitoring area, with heavy, grounded icefloes to the west, north, and east of the drilling site. Brew er et al. (1993) were

unable to determine if either ice or industrial activity by themselves caused the whales to migrate to the north of the dri lling location, but they concluded that ice alone probably did not

determine the observed distribution of whales.

69Humpback whales summering in southeast Alaska did not exhibit persistent avoidance when exposed to seismic pulses from a 1.64-L (100 in 3 ) airgun (Malme and Miles 1985). Some humpbacks seemed “startled” at received levels of 150–169 dB re 1 μ Pa on an approximate rms basis. McCauley et al. (1998, 2000) studied the responses of humpback whales off Western

Australia to a full-scale seismi c survey with a 16-airgun 2678-in 3 array, and to a single 20 in 3 airgun with source level 227 dB re 1 μ Pa·m (p-p). They found that the overall distribution of humpbacks migrating through their study area was unaffected by the full-scale seismic program. McCauley et al. (1998) did, how ever, document localized avoidance of the array and of the single gun. Avoidance reactions began at 5–8 km (2.7–4.3 n.mi.) from the array and those reactions kept most pods about 3–4 km (1.6–2.2 n.mi.) from the operating seismic boat.

Observations were made from the seismic vesse l, from which the maximum viewing distance was listed as 14 km (7.6 n.mi.). Avoidance dist ances with respect to the single airgun were

smaller but consistent with the results from the full array in terms of the received sound levels. Mean avoidance distance from the airgun corresp onded to a received sound level of 140 dB re 1

μ Pa rms; this was the level at which humpbacks started to show avoida nce reactions to an 55 approaching airgun. The standoff range , i.e., the closest point of a pproach of the airgun to the whales, corresponded to a received level of 143 dB rms. The initial avoidance response generally occurred at distances of 5–8 km (2.7–4.3 n.mi.) from th e airgun array and 2 km (1.1 n.mi.) from the single gun. However, some i ndividual humpback whales, especially males, approached within distances 100–400 m (328–1312 ft ), where the maximum received level was

179 dB re 1 μ Pa rms.

Data on short-term reactions (or lack of r eactions) of cetaceans to impulsive noises do not necessarily provide information about long-termeffects. It is not known whether impulsive noises affect reproductive rate or distribution and habitat use in subsequent days or years. However, gray whales continued to migrate annually along the west coast of North America despite intermittent seismic exploration and much ship traffic in that area for decades. Bowhead

whales continued to travel to the eastern Beau fort Sea each summer despite seismic exploration in their summer and autumn range for many years (Richardson et al. 1987) . Populations of both gray whales and bowhead whales grew substantia lly during this time. Humpback and fin whales which occur seasonally in the action areas are lik ely feeding or migrating. The observations summarized above indicate that any fin or humpback whale that is exposed to seismic pulses at particular levels may alter their behaviors. The responses of these whales are likely dependent

on the received level and duration of the airgun pulses, but they may exhibit avoidance, suspend feeding, or shift their migration pathway. Avoidance responses or other behavioral disruptions could be expected to last duri ng the exposure. Whales that are migrating may be diverted from their path or feeding whales may be interrupt ed, but these disruptions would be temporary. Although we do not have evidence to support this assumption for all baleen whales, gray whales have been observed to migrate annually al ong the west coast of North America despite intermittent seismic exploration (and much ship tr affic) and bowhead whales continue to travel to the eastern Beaufort Sea each summer despite seismic exploration in the summer and autumn range for many years. Also, humpback whales exposed to LFA sonar changed song length but then returned to “normal” duration after exposur e (Miller et al 2000). Fin and humpback whales are expected to resume their behavior after th e seismic vessel has move d out of their immediate area without impairment of feeding, migration, or other behaviors.

70Effects from Aircraft Traffic Most offshore aircraft traffic in support of the oil industry involves tu rbine helicopters flying along straight lines. Underwater sounds from aircraft are transient. According to Richardson et al. (1995a), the angle at which a line from the aircraft to the receiver intersects the water’s surface is important. At angles greater than 13 degrees from the vertical, much of the incident sound is reflected and does not pe netrate into the water. Ther efore, strong underwater sounds

are detectable while the aircraft is within a 26-degree cone above the receiver. An aircraft usually can be heard in the air well before and af ter the brief period while it passes overhead and

is heard underwater.

Data on reactions of bowheads, and especially fin and humpback whales , to helicopters are limited. Most bowheads are unlikely to react si gnificantly to occasional single passes by lowflying helicopters ferrying pers onnel and equipment to offshore operations. Observations of bowhead whales exposed to helicopter overflig hts indicate that mostbowheads exhibited no obvious response to helicopter overf lights at altitudes above 150 m (500 ft). At altitudes below 150 m (500 ft), some bowheads probably would dive quickly in response to the aircraft noise (Richardson and Malme 1993). This noise genera lly is audible for only a brief time (tens of seconds) if the aircraft remains on a direct c ourse, and the whales should resume their normal

activities within minutes. Pate naude et al. (1997) f ound that most reactions by bowheads to a Bell 212 helicopter occurred when the helicopter was at altitudes of 150 m or less and lateral

distances of 250 m or less. The most common reac tions were abrupt dives and shortened surface time and most, if not all, reacti ons seemed brief. However, the majority of bowheads showed no obvious reaction to single passes, even at thos e distances. The helicopter sounds measured underwater at depths of 3 and 18 m showed th at sound consisted mainly of main-rotor tones

ahead of the aircraft and tail-ro tor sounds behind the aircraft; mo re sound pressure was received at 3 m than at 18 m; and peak sound levels re ceived underwater diminished with increasing

aircraft altitude. Sound levels received underw ater at 3 m from a Bell 212 flying overhead at 150 m ranged from 117-120 dB re 1 μPa in the 10 -500-Hz band. Underwater sound levels at 18 m from a Bell 212 flying overhead at 150 m ranged from 112-116 dB re 1 μPa in the 10-500-Hz

band.

Fixed-wing aircraft flying at low altitude often cause hasty dive s. Reactions to circling aircraft are sometimes conspicuous if the aircraft is below 300 m (1,000 ft), uncommon at 460 m (1,500 ft), and generally undetectable at 600 m (2,000 ft). Repeated low-altitude overflights at 150 m (500 ft) during aerial photogrammetry studies of feeding bowheads sometimes caused abrupt turns and hasty dives (Richardson and Malme 1993). Aircraft on a direct course usually produce audible noise for only tens of seconds, and the whal es are likely to resume their normal activities within minutes (Richardson and Malme 1993). Pa tenaude et al. (1997) found that few bowheads (2.2%) during the spring migration were observed to react to Twin Otter overflights at altitudes of 60-460 m. Reaction frequency diminished with increasing lateral distance and with increasing altitude. Most observed reactions by bowheads occurred when the Twin Otter was at

altitudes of 182 m or less and lateral distances of 250 m or less. There was little, if any, reaction by bowheads when the aircraft circled at an altitu de of 460 m and a radius of 1 km. The effects from an encounter with aircraft are brief, and the whales should resume their normal activities

within minutes.

71While the obvious behavioral reaction of a bowh ead to a single low-flying helicopter or fixedwinged aircraft flying overhead is probably temporary (Richardson et al. 1995a), most “fleeing” reactions in mammals are accompanied by e ndocrine changes, which, depending on other

stressors to which the individua l is exposed, could contribute to a potentially a dverse effect on

health.

Humpback and fin whales could be also be dist urbed by aircraft noise a ssociated with oil and gas leasing and exploration. Shallenberger ( 1978) reported some humpbacks were disturbed by overflights at 1,000 ft (305 m), wher eas others showed no response at 500 ft (152 m). As with response to airgun noise, pods varied in their response. Humpbacks in large groups showed little or no response, but some adult-only groups exhibited avoidance (H erman et al. 1980).

Information is lacking regarding the potential effects of aircraft noise on fin or humpback whales. It is likely the discussion of these effects on bowhead whales (above) is generally applicable to fin and humpback whales.

On-Ice 2D/3D Seismic Surveys The 2D/3D seismic surveying in shallow water could also be conducted during the winter over the ice and we anticipate that some on-ice surveys could occu r. Seismic profiling on shore-fast ice using vibroseis is another source of introduction of noise in to the arctic environment. Richardson et al. (1995a) summarized that typical signals associat ed with this kind of seismic activity sweep from 10-70 Hz but harmonics exte nd to about 1.5 kHz (Richardson et al. 1995a). In this activity, hydraulically driven pads mounted beneath a line of trucks are used to vibrate, and thereby energize the ice. Noise incidental to the activit y is introduced by the vehicles associated with this activity.

These on-ice surveys often extend into the period in April when bowhead whales begin to be observed at Barrow and are present in the Chukchi and Beaufort Sea in th e spring lead system. However, during that period in the Beaufort Sea, the whales are far offshore in the spring leads

and distant from shallow water areas where such surveys could occur. On-ice surveys are not expected in the Chukchi Sea. These surveys have occurred regularly in nearshore areas of the Alaska Beaufort Sea over the past 30 years. If bowhead whales detect these sounds, there is no indication of any adverse effect on their migratio n or population recovery. For these reasons, we believe that on-ice surveys are not likely to have detectable adve rse effects on bowhead whales. We do not believe these surveys wi ll affect humpback or fin whales because these whales are not present during the periods in which on-ice surveys may occur.

Potential Effects from Expl oratory Drilling Operations Exploration drilling units and ot her drilling units ar e sources of noise and disturbance to bowhead whales. Exploration drilling in the Beaufort Sea can be conducted from manmade gravel islands, ice islands, caisson-retained is lands, bottom-founded drilling platforms such as the concrete island drilling system or single steel drilling caisson, or from drillships in deeper water supported by icebreakers. The type of drilling platform used depends on water depth, oceanography, ice cover, and other factors. Stationary sources of offshore noise (such as drilling units) appear less disruptive to bowhead whales than moving sound sources (such as vessels).

72Drilling operations from many of these structures except drillshi ps are likely to be conducted during the winter months. Drilling from ice is lands would occur only during the winter when bowheads are not present, and noise from these activities would not affect bowhead whales. Therefore, this type of drilling activity is not discussed here.

MMS anticipates that gravel islands are not likel y to be constructed for exploratory drilling in OCS waters, but that old artifici al islands might be used tempor arily. In the near future MMS expects that exploratory drilling in the Beaufort Sea will also be conducted from other platforms and during the open water period depending on wate r depth, sea ice conditions, availability of drilling units, and the ice-resi stance of units. MMS said moveable platforms resting on the seafloor could be used to drill in water depths of 10-20 m, but that dril lships or other floating units would be used in deeper water. Drilli ng from these units will be in open water. Such drilling would be supported by icebreakers and supply boats.

In the Beaufort Sea, MMS assumes a maximum of two drilling rigs would operate at any one time with a total of six explor ation wells and six delineation we lls drilled over an eight year period, beginning in 2007. Explor ation drilling in the Chukchi Sea evaluation area could begin as early as 2008. Drilling operati ons in the Chukchi Sea are likelyto employ drillships with icebreaker support vessels and to operate at a given well site between 30 and 90 days. MMS assumes one to two exploration wells per se ason drilled between June-November. No exploration drilling from Sa le 193 would occur in the polynya. Thus, based on the aforementioned scenario, fin, humpback, or bowh ead whales could potentially encounter a total of 3 exploration drilling units w ithin evaluation areas, with iceb reaker support possible in the Chukchi Sea and likely in the Beaufort Sea. Beginning in 2012, production and injection wells may also be drilled.

Noise-producing activities, such as drilling ope rations, in the spring lead and polynya system during the spring bowhead migration have a fairly high potential of affec ting the whales. MMS

has decided not to allow seismic survey activity in the spring lead system through late June, or as prescribed by NMFS to protect bowhead whales. No exploration activiti es would occur in the spring lead system from Sale 193. Exploration drilling from future OC S sales would not occur before 2011. At this time, it is unknown whethe r future Chukchi Sea Sales will include or exclude the spring lead system. The general lo cation of the spring lead system is based on relatively limited survey data and is not well defined.

Previously, MMS concluded that exploratory drilling operations using floating platforms within the portion of the Beaufort Sea spring lead sy stem during the bowhead migration are unlikely,

because the ice at this time of year would be too thick for floating drilling platforms to get to the location and conduct drilling operations, even with icebreaker support. Thus, in the Beaufort Sea multiple-sale EIS, MMS concluded that spri ng-migrating bowheads are not likely to be exposed to drilling noise from activities on l eases from Sales 186, 195, or 202. MMS concluded that areas in or near the spring lead system in the Beaufort Sea could be leased during these sales, but any exploratory dril ling operations likely would be conducted during the open-water season (August-October) using fl oating drilling platforms.

73Future lease sale decisions will determine whethe r the polynya area will be offered for lease in the future. No exploratory drilling in the Chukc hi Sea portion of the lead system could begin unless tracts within the polynya area are offered and leased. Op en water in this polynya area typically begins in June and continues through November.

Some bowheads in the vicinity of drilling operations would be expected to respond to noise from drilling units by slightly cha nging their migration speed and swimming direction to avoid closely approaching these noise sources. Mile s, Malme, and Richardson (1987) predicted the zone of responsiveness to continuous noise sour ces. They predicted th at roughly half of the bowheads likely would respond at a distance of 0.02-0.2 km (0.12-1.12 mi) to drilling from an artificial island when the signal-to-noise ratio is 30 dB. By comparison, they predicted that roughly half of the bowheads likely would respo nd at a distance of 1-4 km (0.62-2.5 mi) from a drillship drilling when the signal- to-noise ratio is 30 dB. A smaller proportion would react when the signal-to-noise ratio is a bout 20 dB (at a greater distance from the source), and a few may react at a signal-to-noise ratio even lower or at a greater distance from the source.

Drilling for oil and gas generally produces low-frequency sounds with strong tonal components. There are few data on the noise from conventional drilling platforms. Recorded noise from an early study of one drilling platform and three combined drilling production platforms found that noise was so weak, it was almost not detectable alongside the platform at sea states of 3 or above. The strongest tones were at very low frequencies near 5 Hz , and received levels of these

tones at near-field locations were 119- 127 dB re 1 μPa (Richardson et al. 1995a).

Although underwater sounds from drilling on some artificial islands and caissons have been measured, little information is available about reactions of bowheads to drilling from these

structures. Underwater noise levels from drilling operations on natural barrier islands or

artificial islands are low and ar e not audible beyond a few kilomete rs (Richardson et al. 1995a). Noise is transmitted very poorly from the drill-rig machinery through land into the water. Even under open-water conditions, drilli ng sounds are not detectable ve ry far from the structure. Drilling noise from caisson-retained islands is much stronger. At least during open-water conditions, noise is conducted more directly into the wa ter than from island drill sites. Noise associated with drilling activities at both sites varies considerably with ongoing operations. The highest documented levels were transient pu lses from hammering to install conductor pipe. NMFS (2001) concluded that:

...bowhead whale responses to noise from drilling and exploration activities are expected to depend on the type of activity and its location relative to the whales’ normal migration corridors...Thus, a drill ship opera ting offshore and closer to the center of the migration is expected to have a greater biol ogical impact than a drilling operation from an artificial island situated in very shallow water along the nearshore edge of the migration

.

Artificial Gravel Islands

Shallow nearshore waters of the Beaufort Sea ar e suitable for development of artificial gravel islands to support oil production. Costs are prohib itive for use of this technology for exploratory activities. Compared to caissons emplaced on th e ocean bottom, platforms standing on legs, or drilling vessels, offshore drilling from natu ral or man-made islands generally produces

74underwater sounds that are weak and do not propagate beyond a few kilometers (Richardson et al. 1995). The following is a brief discussion of several studies on the measurement of

underwater noise and the effects of noise from drilling operations on gravel islands on bowhead whales. Although we are uncertain of the im pacts to fin and humpback whales, similar conclusions for these two baleen sp ecies may be reasonable to assume.

Seal Island: Noise measurements were made during the open-water season near Seal Island, a manmade gravel island off Prudhoe Bay in water 12 m deep. Seal Island is the approximate location for the Northstar Proj ect. Davis, Greene, and McLa ren (1985) measured underwater noise from Seal Island during the open-water s eason while well logging was occurring but not drilling operations. Underwater sound leve ls recorded from bottom hydrophones 1.65-2.4 km from Seal Island were strongly affected by wind speed and active barge or tug traffic at the island. The strongest tone measured was 486 Hz from turbochargers on the generators used for well-logging operations. This tone was measur ed by a hydrophone on a boat at distances of up

to 5 km from Seal Island. Noise associated w ith barge or tug movement at the island readily could be detected at 2.4 km from the island, ev en during high winds. Noise levels in the 20- 1,000-Hz band from barge traffic were about 118 dB re 1 μPa at 1.6 km and had decreased to 108-110 dB re 1 μPa at 2.4 km. At that rate of sound attenuation, the no ise level from barges

was estimated to be about 92 dB at 6 km. U nderwater sounds from Seal Island were not detectable 2.3 km away while people were on th e island and power generators were operating, but no logging or drilling operations were ongoing.

Aerial surveys for bowhead whales near Seal Island in 1982 (during isla nd construction) and

1984 found that most whales were in water deeper than 18 m, which is consistent with data from previous studies (Davis, Greene, and McLaren 1985). In 1982, one whale was sighted in 12 m

of water about 11 km northwest of Seal Isla nd. In 1984, there were two sightings of single whales in 12-15 m of water. Whales migrating in water deeper than 18 m would have been too far away to detect noise from Seal Island, becau se industrial noise was not audible in the water more than a few kilometers away. Acoustic da ta collected in 1982 and 1984 suggest that some

bowheads were closer to S eal Island in 1984 than in 1982. Localizations made by the hydrophone array on three occasions indicated the whales were present between 2.5 and 6 km from Seal Island. Bowhead calls recorded on hydrophones were thought to be from whales that were in water at least 18 m deep. The study c oncluded that there was no evidence to suggest

that bowheads avoided Seal Is land in 1984 compared to 1982.

Sandpiper Island: Johnson et al. (1986) measured underwater noise from Sandpiper Island, a manmade gravel island in water 15 m deep. Sound was measured using a bottom-hydrophone system at 0.5 km from the island and sonobuoys at greater distances from the island. The

median sound levels observed at a fixed locatio n 0.5 km from Sandpiper Island were relatively low. Median noise levels in the 20-1,000-Hz band were 93 and 95 dB re 1 μPa during two periods without drilling and 100 dB re 1 μPa during one period with drilling. In the absence of shipping or other industrial sounds , the expected level of noise in the 20-1,000-Hz band is about 100 dB re 1 μPa for Beaufort Sea State 2 cond itions (wind speeds at 7-10 kn and wave heights up to 0.5 m). The most obvious components were tones at 20 and 40 Hz, which were attributed to power generation on the island.

75The low-frequency industrial sounds from Sandp iper Island attenuated ra pidly with increasing range, at least partially due to the shallow water. The low-frequency sounds were evident when ambient noise levels were low but were largel y masked during periods when ambient noise was above average. Sound levels received at a s onobuoy 3.7 km from Sandpiper Island (76 dB re 1 μPa in both the 20- and 40-Hz ba nds) were 24-30 dB lower than the levels received at the bottom hydrophone 0.5 km from the island. The bottom hydrophone measured drilling sounds of 100 dB re 1 μPa in the 20-Hz-frequency band at 0.5 km from Sandpiper Island. The sounds were severely attenuated at 3.7 km and not detectable at 9.3 km. The effective source level of the 40-Hz tone was estimated at 145 dB re 1 μPa at 1 m.

Impulsive hammering sounds associated with inst allation of a conductor pipe were as high as 131-135 dB re 1 μPa at 1 km, when pipe depth was about 20 m below the island. In contrast, broadband drilling noise at this distance was about 100-106 dB. During hammering, the transient signals had the str ongest components at 30-40 Hz a nd about 100 Hz. Moore et al. (1984, as cited in Richardson et al. 1995b) reported that received levels fo r transient piledriving

sounds recorded at 1 km from a manmade island near Prudhoe Bay were 25-35 dB above ambient levels in the 50- to 200-Hz band. They estimated that the sounds might be received underwater as far as 10-15 km from the source, fa rther than drilling sounds. Aerial surveys for

bowhead whales in 1985 indicate d that no bowheads were seen closer than 30 km from Sandpiper Island (Johnson et al. 1986). Almost a ll of the migrating bowhe ads traveled in water deeper than 18 m, as was found in the surveys fo r Seal Island. Sandpiper and Northstar islands are both about 6 km south of the 18-m-depth c ontour. Industrial noise from Sandpiper Island, with or without drilling, was not audible in the water more than a few kilometers away. Because the migration route of almost all bowheads is no rth of the 18-m contour, few individual whales

moved into the zone where industria l noise potentially was detectable.

The authors concluded that the number of whales that passed along the southern edge of the migration route and approached th e artificial islands, both Seal a nd Sandpiper, must have been a very low fraction of the total population given the absence of sightings cl ose to the islands.

Tern Island : Studies at Tern Island were conducted to determine sound levels that could be expected from the Liberty development project. The studies provide in formation on distances

that sound travels as a result of activities on gravel islands.

Greene (1997) measured underwater sounds under the ice at the Liberty Island location from drilling operations on Tern Island in Foggy Island Bay in February 1997. Sounds from the drill rig generally were masked by ambi ent noise at distances near 2 km . The strongest tones were at frequencies below 170 Hz, but the received levels diminished rapidly with increasing distance and dropped below the ambient noise level at ra nges of about 2 km. Drilling sounds were not detected at frequencies above 400 Hz, even at 200 m from the drill rig.

Northstar Island : Formerly known as Seal Island, British Petroleum expanded this island for oil production in 2000, with produc tion beginning in October 2001. Two pipelines connect the

island to shore-based infrastructure and the Tran s-Alaska Pipeline. An extensive acoustic monitoring program was implemented for the Norths tar project. That work found that in-water drilling sounds from the island reached backgroun d levels at distances of 2-4km (Richardson

762006). Noise from the island was higher duri ng construction. During production, researchers were unable to detect any diffe rences in broadband sound pressure levels with and without drilling. The most important contributor to noise from the Norths tar project was associated with vessels (crew boats, tugs, a nd self-propelled barges).

Oooguruk and Nikaitchuq Islands Two offshore production pads (islands) are curr ently being developed in Harrison Bay near

Oliktok Point. Produced oil from these faciliti es will be delivered by sub-sea pipelines which utilize pipe-in-pipe technology to reduce the risk of failure and sp ills. These will be in very shallow water; depths are less than 3 meters. Large whales would not occur at these sites,

however in-water noise could extend out to deeper waters where whales (mainly bowhead whales) may be found. In-water noise was measured during constr uction of the Oooguruk Island facility in 2006 (Zykov, Hannay, and Link 2007). Noise levels at 1 mile were measured at 92 dB re 1 μPa, and not detectable at 4 miles. Tug and barge noise had higher detections, as expected.

Bottom-Founded Structures Two types of drilling platforms have been used fo r offshore drilling in the Alaska Beaufort Sea: the concrete island drilling system, which is a floa ting concrete rig that is floated into place, ballasted with seawater, and sits on the seafloor ; and the single steel dril ling caisson, which is a section of a ship with a drill rig mounted on it and also is floated into place, ballasted with seawater, and sits on the seafl oor. Drilling from these platforms generally begins after the bowhead whale migration is done and continues through the winter season.

In the absence of drilling opera tions, radiated levels of underw ater sound from the concrete island drilling system were low, at least at fre quencies above 30 Hz. The overall received level was 109 dB re 1 μPa at 278 m, excluding any infr asonic components. When the concrete island drilling system was operating in early winter, radiated sound le vels above 30 Hz again were relatively low (89 dB at 1.4 km). However, when infrasonic components were included, the

received level was 112 dB at 1.4 km. More than 99% of the sound energy received was below

20 Hz. Received levels of sound at 222- 259 m ranged from 121-124 dB. The maximum

detection distance for infrasonic sounds was not de termined. Such tones likely would attenuate rapidly in water shallow enough for a bottom-founde d structure. Overall, the estimated source

levels were low for the concrete island drilli ng system, even when the infrasonic tones were included (Richardson et al. 1995a).

Sounds from the steel drilling caisson were me asured during drilling operations in water 15 m deep with 100% ice cover. Th e strongest underwater tone was at 5 Hz (119 dB re μPa) at a

distance of 115 m. The 5-Hz tone apparently was not detectable at 715 m, but weak tones were present at 150-600 Hz. The broadband (20- 1,000 Hz) received level at 215-315 m was 116-117 dB re μPa, higher than the 109 dB reported for the concrete island drill ing system at 278 m.

Inupiat whalers believe that noise from drilling activi ties displace whales farther offshore, away from their traditional hunting areas. These c oncerns were expressed primarily for drilling activities from drillships with icebreaker suppor t that were operating offshore in the main migration corridor. Concerns also have been expressed about noise generated from the single

77steel drilling caisson, the drilling platform used to drill two wells on the Cabot Prospect east of

Barrow in October 1990 and November 1991. Mr. Jacob Adams, Mr. Burton Rexford, Mr. Fred Kanayurak, and Mr. Van Edwardson, all with the Barrow Whaling Captain’s Association, stated in written testimony at the Arctic Seismic Synthesis and Mitigating Measures Workshop on March 5-6, 1997, in Barrow: “We are firmly c onvinced that noise from the Cabot drilling platform displaced whales from our traditional hunting area. This resulted in us having to go

further offshore to find whales ” (USDOI, MMS 1997).

No data were found to describe pos sible reaction of humpback or fi n whales to these structures. However, we would expect these whales would show similar response as bowhead whales. We expect bottom-founded structures would be used primarily in the more shallow waters of the eastern Beaufort Seas, beyond the present range of fin and humpback whales.

Drillships and other Floating Platforms Bowhead reaction to drillships is variable. Bowhead whales whose behavior appeared normal

have been observed on several occasions with in 10-20 km (6.2-12.4 mi) of drillships in the eastern Beaufort Sea, and there have been a number of reports of sightings within 0.2-5 km (0.12-3 mi) from drillships (Richardson et al. 1985a; Richardson and Malme 1993). On several occasions, whales were well within the zone wher e drillship noise should be clearly detectable by them. In other cases, bowheads may avoid dril lships and their support vessels at 20-30 km (see below and NMFS, 2003a). The factors asso ciated with the variability are not fully

identified or understood.

Richardson and Malme (1993) point out that the data, although lim ited, suggest that stationary industrial activities prod ucing continuous noise, such as sta tionary drillships, result in less dramatic reactions by bowheads than do moving sources , particularly ships. It also appears that

bowhead avoidance is less around an unattended structure than one attended by support vessels. Most observations of bowheads tolerating nois e from stationary operations are based on opportunistic sightings of whal es near ongoing oil-industry oper ations, and it is not known whether more whales would have been present in the absence of those operations. Because

other cetaceans seem to habituate somewhat to continuous or repeated noise exposure when the noise is not associated with a harmful event, th is suggests that bowheads will habituate to certain noises that they learn are nonthreatening. Additi onally, it is not known what components of the population were observed around the dr illship (e.g., adult or juvenile males, adult females, etc.).

In Canada, bowhead use of the main area of oi l-industry operations within the bowhead range was low after the first few years of intensiv e offshore oil explora tion in 1976 (Richardson, Wells, and Wursig 1985), suggesting perhaps cumula tive effects from repeated disturbance may

have caused the whales to leave the area. In the absence of systematic data on bowhead summer distribution until several years after intensive in dustry operations began, it is arguable whether the changes in distribu tion in the early 1980’s were greater than natural annual variations in distribution, such as responding to changes in the location of food sources. Ward and Pessah (1988) concluded that the avai lable information from 1976-1985 and the historical whaling information do not support the suggestion of a tr end for decreasing use of the industrial zone by

bowheads as a result of oil and gas exploration activities. They concluded that the exclusion hypothesis is likely invalid.

78The distance at which bowheads may react to dril lships is difficult to gauge, because some bowheads would be expected to respond to noise from drilling units by changing their migration speed and swimming direction to avoid closely a pproaching these noise sources. For example, in the study by Koski and Johnson (1987), one whale a ppeared to adjust its course to maintain a distance of 23-27 km (14.3-16.8 mi) from the center of the drilling operatio n. Migrating whales apparently avoided the ar ea within 10 km (6.2 mi) of the drillship, passing both to the north and to the south of the drillship. The study dete cted no bowheads within 9.5 km (5.9 mi) of the drillship, and few were observed within 15 km ( 9.3 mi). The principal finding of this study was that migrating bowheads appeared to avoid the offshore drilling operation in fall 1986. Thus, some bowheads may avoid noise from drills hips at 20 km (12.4 mi) or more. In other studies, Richardson, Wells, and Wursig (1985) observed three bowheads 4 km (2.48 mi) from operating drillships, well with in the zones ensonified by dril lship noise. The whales were not heading away from the drillship but we re socializing, even though exposed to strong drillship noise. Eleven additional whales on three other occasions were observed at distances of 10-20 km (6.2-12.4 mi) from operating drillships. On two of the occasions, drillship noise was not detectable by researchers at distances fr om 10-12 km (6.2-7.4 mi) and 18-19 km (11.2-11.8 mi), respectively. In none of the occasions were whales heading away from the drillship. Ward and Pessah (1988, as cited in Richardson and Ma lme 1993) reported observations of bowheads within 0.2-5 km (0.12-3 mi) from drillships.

The ice-strengthened Kulluk, a sp ecialized floating platform de signed for arctic waters, was used for drilling operations at the Kuvlum drilling site in western Camden Bay in 1992 and

1993. Data from the Kulluk indicated broadband source levels (10-10,000 Hz) during drilling and tripping were estimated to be 191 and 179 dB re μPa at 1 m, respectively, based on measurements at a water depth of 20 m in water about 30 m deep (Richardson et al. 1995a).

Hall et al. (1994) conducted a s ite-specific monitoring program around the Kuvlum drilling site in the western portion of Camden Bay during the 1993 fall bowhead whale migration. Results of their analysis indicated th at bowheads were moving through Camden Bay in a significantly nonrandom pattern but became more randomly distri buted as they left Camden Bay and moved

to the west. The results also indicated that whales were distributed farther offshore in the proximal survey grid (near the drill site) than in the distant survey grid (a n area east of the drill site), which is similar to results from previous studies in this general area. The authors noted that information from previous studies indicated that bowheads routinely were present nearshore

to the east of Barter Island a nd were less evident close to shor e from Camden Bay to Harrison Bay (Moore and Reeves, as cited in Hall et al., 1994). The authors believed that industrial

variables such as received level were insufficien t as a single predictor va riable to explain the 1993 offshore distribution of bowhead whales, and they suggested that water depth was the only variable that accounted for a sign ificant portion of the variance in the model. They concluded that for 1993, water depth, received level, and longitude accounted for 85% of the variance in

the offshore distribution of the whales. Based on their analyses, the authors concluded that the

1993 bowhead whale distribution fell within the parameters of previously recorded fallmigration distributions.

79Davies (1997) used the data from the Hall et al. study in a Geographic Information System model to analyze the distributi on of fall-migrating bowheads in relation to an active drilling operation. He also concluded that the whales were not randomly distributed in the study area, and that they avoided the regi on surrounding the drill site at a range of approximately 20 km (12.4 mi). He noted that the whales were located significantly farther offshore and in significantly deeper water in th e area of the drilling rig. As noted by Hall et al. (1994), the

distribution of whales observed in the Camden Bay area is cons istent with previous studies (Moore and Reeves 1993), where whales were observ ed farther offshore in this portion of the Beaufort Sea than they were to the east of Barter Island. Davi es concluded, as did Hall et al., that it was difficult to separate the effect of the drilling operation from other independent

variables. The model identified distance from the drill rig and water depth as the two environmental factors that were most strongly associated with the obs erved distribution of bowheads in the study area. The Davies analysis , however, did not note th at surface observers (Hall et al. 1994) observed whales much closer to the drilling unit and su pport vessels than did aerial observers. In one instance, a whale was observed approximately 400 m (436 yd) from the drill rig. Hall et al. suggest that bowheads, on several occasions, were closer to industrial activity than would be suggested by an examination of only aerial-survey data.

Schick and Urban (2000) also anal yzed data from the Hall et al . study and tested the correlation

between bowhead whale distribution and variables such as water de pth, distance to shore, and distance to the drilling rig. The distribution of bowhead whales around the active drilling rig in 1993 was analyzed and the results indicated that whales were distributed farther from the drilling rig than they would be under a random s cenario. The area of avoidance was localized and temporary (Schick and Urban 2000); Schick and Urban stated they could not conclude that noise from the drilling rig caused the low density near the rig, because they had no data on actual noise levels. They also not ed that ice, an important vari able, is missing from their model and that 1992 was a particularly heavy ice year . Because ice may be an important patterning variable for bowheads, Schick and Urban said they were precluded from drawing strong

inference from the 1992 results with reference to the interaction between whales and the drilling rig. Moore and DeMaster (1998, as cited in Schick and Urban 2002) proposed that migrating bowheads are often found farther offshore in heavy ice years because of an apparent lack of feeding opportunities. Schick and Urban (2002) stated that ultimately, the pattern in the 1992 data may be explained by the presence of ice rather than by the pres ence of the drilling rig.

In playback experiments, some bowheads showed a weak tendency to move away from the sound source at a level of drillship noise comp arable to what would be present several kilometers from an actual drillship (Ric hardson and Malme 1993). In one study, sounds recorded 130 m (426 ft) from th e actual Karluk drill rig were used as the stimulus during disturbance test playbacks (Ric hardson et al., 1991). For the overall 20- to 1,000-Hz band, the average source level was 166 dB re 1 μPa in 1990 and 165 dB re 1 μPa in 1989. Bowheads continued to pass the projector while normal Karluk drilling sounds were projected. During the playback tests, the source level of sound wa s 166 dB re 1 μPa. One whale came within 110 m (360 ft) of the projector. Many whales came within 160-195 m (525-640 ft), where the received broadband (20-1,000 Hz) sound levels were about 135 dB re 1 μPa. That level was about 46 dB above the background ambient level in the 20- to 1,000-Hz band on that day. Bowhead movement patterns were strongly affected when th ey approached the opera ting projector. When

80bowheads still were several hundred meters away, most began to move to the far side of the lead from the projector, which did not happen during c ontrol periods while the projector was silent.

In a subsequent phase of this continui ng study, Richardson et al . (1995b) concluded:

...migrating bowheads tolerated exposure to high levels of continuous drilling noise if it was necessary to continue their mi gration. Bowhead migration was not blocked by projected drilling sounds, and there was no evidence that bowheads avoided the projector by distances exceeding 1 kilometer (0.54 nautical mile). However, local movement patte rns and various aspects of the

behavior of these whales we re affected by the noise exposure, sometimes at distances considerably exceeding the closest points of approach of bowheads to the operating projector

.

Richardson et al. (1995b) reported that bowhead whale avoidance behavior has been observed in half of the animals when exposed to 115 dB re 1 μPa rms broadband drillship noises. However, reactions vary depending on the whale activity, noise characterist ics, and the physical situation (Richardson and Greene, 1993).

Some migrating bowheads diverted their course enough to remain a few hundred meters to the side of the projector. Surfacing and respira tion behavior, and the o ccurrence of turns during surfacings, were strongly affected out to 1 km ( 0.62 mi). Turns were unus ually frequent out to 2 km (1.25 mi), and there was evidence of subtle behavioral effects at distances up to 2-4 km (1.25-2.5 mi). The study concluded that the dem onstrated effects were localized and temporary and that playback effects of drilling noise on distribution, movements, and behavior were not biologically significant.

The authors stated that one of the main limitati ons of this study (during all 4 years) was the inability of a practical sound projector to repr oduce the low-frequency components of recorded industrial sounds. Both the Karluk rig and the icebreaker Robert Lemeur emitted strong sounds down to ~10-20 Hz, and quite likely at even lowe r frequencies. It is not known whether the under-representation of low-frequency compone nts (less than 45 Hz ) during icebreaker playbacks had significant effects on the responses by bowheads. Bowheads presumably can hear sounds extending well below 45 Hz. It is su spected but not confirme d that their hearing

extends into the infrasonic ra nge below 20 Hz. The authors be lieved the projector adequately reproduced the overall 20- to 1,000-Hz level at distances beyond 100 m (109 yd), even though components below 80 Hz were under-represented. If bowheads are no more responsive to sound components at 20-80 Hz than to those above 80 Hz, then the playbacks provided a reasonable test of the responsiveness to com ponents of Karluk sound above 20 Hz.

The authors also stated that th e study was not designed to test the potential reactions of whales

to nonacoustic stimuli detected vi a sight, olfaction, etc. At le ast in summer/autumn, responses of bowheads to actual dredges and drillships seem consistent with reactions to playbacks of recorded sounds from those same sites. Additional limitations of the playbacks identified by the authors included low sample sizes and the fact that responses were only evident if they could be

seen or inferred based on surface observations . The numbers of bowhead whales observed during both playback and control conditions were low percentages of the total Beaufort Sea population. Also, differences be tween whale activities and beha vior during playback versus

81control periods represent the in cremental reactions when playb acks are added to a background of

other activities associated with the research. Thus, playback results may somewhat understate the differences between truly undisturbed whales versus th ose exposed to playbacks.

Few data were found to describe possible reaction of hu mpback or fin whales to drillships and other floating platforms. Malme (in Rich ardson et al. 1995) obser ved reactions among humpback whales exposed to drillship, semi-s ubmersible, drilling platform, and production platform noises and found no clear responses at broadband received levels up to 116 dB. Again, we would expect fin and humpback whales generally would show similar response as bowhead whales, reacting more at higher r eceived levels or to start-up or transient signals. The data suggest that stationary industria l activities producing continuous noise result in less dramatic reactions by cetaceans than do moving sound sour ces, particularly ships (Richardson et al. 1995). However, bowhead whales may be especially sensitive to such noise.

Icebreakers If drillships are attended by iceb reakers, as typically is the case during the fall in the U.S. Beaufort Sea, and we expect to be the case in the Chukchi Sea, the drillship noise frequently may be masked by icebreaker no ise, which often is louder. Response distances would vary, depending on icebreaker activities and sound- propagation conditions. Based on models, bowhead whales likely would respond to the sou nd of the attending icebr eakers at distances of 2-25 km (1.24-15.53 mi) from the icebreakers (Mile s, Malme, and Richardson 1987). Zones of responsiveness for intermittent sounds, such as an icebreaker pushing ice have not been studied. This study predicts that roughly half of the bowhead whales s how avoidance response to an icebreaker underway in open water at a rang e of 2-12 km (1.25-7.46 mi) when the sound-tonoise ratio is 30 dB. The study also predicts that roughly half of th e bowhead whales would show avoidance response to an icebreaker pus hing ice at a range of 4.6-20 km (2.86-12.4 mi)

when the sound-to-noise ratio is 30 dB.

Richardson et al. (1995b) found that bowheads migrating in the n earshore lead often tolerated exposure to projected icebreaker sounds at received levels up to 20 dB or more above the natural ambient noise levels at corresponding frequencies. The source level of an actual icebreaker is much higher than that of the projectors (project ing recorded sound) used in this study (median difference 34 dB over the frequency range 40-6,3 00 Hz). Over the two-season period (1991 and 1994) when icebreaker playbacks were attempted, an estimated 93 bowheads (80 groups) were seen near the ice camp when the projectors were transmitting icebreaker sounds into the water, and approximately 158 bowheads (116 groups) were s een near there during quiet periods. Some bowheads diverted from their course when expos ed to levels of proj ected icebreaker sound greater than 20 dB above the na tural ambient noise level in th e one-third octave band of the strongest icebreaker noise. However, not all bow heads diverted at that sound-to-noise ratio, and a minority of whales apparently diverted at a lower sound-to-noise ratio. The study concluded that exposure to a single playb ack of variable icebreaker sou nds can cause statistically but probably not biologically significan t effects on movements and behavi or of migrating whales in the lead system during the spring migration eas t of Point Barrow. The study indicated the predicted response distances for bowheads ar ound an actual icebreak er would be highly variable; however, for typical traveling bowheads, detectab le effects on movements and behavior are predicted to extend commonly out to radii of 10-30 km (6.2-18.6 mi).

82It should be noted that these pr edictions were based on reactions of whales to playbacks of icebreaker sounds in a lead syst em during the spring migration a nd are subject to a number of qualifications. The predicted “typical” radius of responsiveness around an icebreaker like the

Robert Lemeur is quite variable, because propagation c onditions and ambien t noise vary with time and with location. In addition, icebreakers vary widely in engine power and thus noise output, with the Robert Lemeur being a relatively low-powered icebreaker. Furthermore, the

reaction thresholds of individual whales vary by at least 10 dB around the “typical” threshold, with commensurate variability in predicted reaction radius.

Richardson et al. (1995a) reported that broadband (20-1,000 Hz) rece ived levels at 0.37 km for the icebreaking supply vessel th e Canmar Supplier underway in open water were 130 dB and 144 dB when it was breaking ice. The increase in noise during icebreaking is apparently due to propeller cavitation. Richardson et al. (1995a) summarized that icebreaking sound from the Robert Lemeur pushing on ice were detectable >50 km away. We anticipate that an icebreaker would attend a drillship in the Chukchi Sea. Brew er et al. (1993) reported that in the autumn of 1992, migrating bowhead whales avoided an iceb reaker-accompanied drillship by 25+ km. This ship was icebreaking almost daily. However, Richardson et al. ( 1995a) noted that in 1987,

bowheads also avoided another drills ite with little icebreaking.

No data were found to describe pos sible reaction of humpback or fi n whales to icebreakers. We would not expect icebreaking to be an issue for these species for the proposed actions, as their distribution is primarily within the Chukchi and western Beaufort Seas where ice management is less likely to be needed to support exploratory activity.

Vessel Traffic Bowheads react to the approach of vessels at gr eater distances than they react to most other

industrial activities. Accordi ng to Richardson and Malme (1993), most bowheads begin to swim rapidly away when vessels appro ach rapidly and directly. This avoidance may be related to the fact that bowheads have been commercially hunt ed within the lifetimes of some individuals within the population and they continue to be hunted for subsistence throughout many parts of their range. Avoidance usually begins when a rapidly approaching vessel is 1-4 km (0.62-2.5 mi) away. A few whales may react at distances from 5-7 km (3-4 mi), and a few whales may not react until the vessel is less than 1 km (le ss than 0.62 mi) away. Received noise levels as low as 84 dB re 1 μPa or 6 dB above ambient may elicit strong avoidanc e of an approaching vessel at a distance of 4 km (2.5 mi) (Richardson and Malme 1993).

In the Canadian Beaufort Sea, bowheads observed in vessel-disturbance experiments began to orient away from an oncoming vessel at a range of 2-4 km (1.2-2.5 mi) and to move away at increased speeds when approached closer than 2 km (1.2 mi) (Richardson and Malme 1993). Vessel disturbance during these experimental conditions temporarily disrupted activities and sometimes disrupted social groups, when groups of whales scattered as a vessel approached. Reactions to slow-moving vessels , especially if they do not approach directly, are much less

dramatic. Bowheads often are more tolerant of ve ssels moving slowly or in directions other than toward the whales. Fleeing from a vessel ge nerally stopped within minutes after the vessel passed, but scattering may persist for a longer period. After some disturbance incidents, at least

83some bowheads returned to th eir original locations (Richa rdson and Malme 1993). Some whales may exhibit subtle change s in their surfacing and blow cycles, while others appear to be unaffected. Bowheads actively engaged in social interactions or mating may be less responsive

to vessels. Data are not sufficient to determin e sex, age, or reproducti ve characteristics of response to vessels. We are not aware of data th at would allow us to determine whether females with calves tend to show avoidance and scattering at a greater, lesser, or at the same distances as other segments of the population.

The encounter rate of bowhead whales with ve ssels associated with exploration would be determined by which areas were being explored . Bowhead whales probably would encounter relatively few vessels associated with explora tion activities during thei r fall migration through the Alaskan Beaufort Sea. Vessel traffic gene rally would be limited to routes between the exploratory-drilling units and the shore base. Each floating drilling unit probably would have one vessel remaining nearby for emergency use. Depending on ice condi tions, floating drilling units may have two or more icebreaking vessels standing by to perform ice-management tasks. It is likely that vessels actively involved in ice management or moving from one site to another would be more disturbing to whal es than vessels idling or mainta ining their position. In either case, bowheads probably would adjust their i ndividual swimming paths to avoid approaching

within several kilometers of vessels attendi ng a drilling unit and proba bly would move away from vessels that approached within a few k ilometers. Vessel activities associated with exploration are not expected to disrupt the bowhead migration, and small deflections in individual bowhead-swimming paths and a reduc tion in use of possible bowhead-feeding areas near exploration units should not result in si gnificant adverse effects on the species. During their spring migration (April th rough June), bowheads likely would encounter few, if any, vessels along their migration route, because ice at this time of year typically would be too thick for seismic-survey ships, drillships , and supply vessels to operate in.

In 2003, there was concern by Alaskan Native whalers that barge traffic associated with oil and gas activities might have caused bowhead whales to move farther offshore and, thus, to be less

accessible to subsistence hunters. In addition to acting as a source of noise and disturbance, marine vessels could potentially strike bowhead wh ales, causing injury or death. As noted in the baseline section of this evaluation, available in formation indicates that current rates of vessel strikes of bowheads are low. At present, availa ble data do not indicate th at strikes of bowheads by oil and gas-related vessels will become an im portant source of injury or mortality in the Beaufort Sea Planning Area. Risk of strikes would increase as ve ssel traffic in bowhead habitat

increases.

Information is sparse regarding fin whale respons e to vessels, while cons iderable work exists regarding humpback whale response . Richardson et al (1995) pres ents a discussion of pertinent research here, finding that humpbacks overall at tempted to avoid vessels and displayed such behavioral responses as aggressi veness, increased surfacing, or ch anges in dive patterns. In research in southeast Alaska, humpback whales moved away from large cruise boats when approached within a few kilometers (Richards on et al. 1995). Similar to bowhead whales, humpback whales seem less likely to react to vessel noise when actively feeding than when resting or engaged in other activities (Richardson et al. 1995). The most extensive data set on

this issue exists for the A tlantic seaboard at summering grounds off Cape Cod. There,

84humpback whales are regularly found and continue to return each year despite exposure to many ships, fishing vessels, and whale watchi ng boats (Richardson et al. 1995).

The Chukchi Sea Planning Area experiences relativel y low volumes of marine traffic associated with fishing, recreation, and co mmercial-shipping traffic at th is time, as transit activities normally occur closer to shore than the boundary of the Planning Area. Traffic presently is limited to research vessel cruises, some of wh ich engage in a variety of seismic-survey operations, and energy-related seismic-survey support activity. Incr eases in support-vessel traffic in habitats occupied by humpback whales would increase the risk of collision. Risk of collision to humpbacks of the WNPS is very low in U.S. waters and is not an important source of injury or mortality. Seismic-survey vessels and accompanying support vessels could adversely affect fin and humpback whales by inducing avoidance responses. The incremental

additional marine traffic noise by transiting seismic vessels woul d remain short term, and total

traffic volume would remain low. In the wester n Beaufort OCS, seismic-survey vessel-transit noise would add incrementally to the volume of marine traffic noise experienced in that area, but it would not add substantially to the current levels of volume of traffic or noise. Currently all vessels (including seismic-survey support vessels) are required to comply with law that forbids a person subject to the jurisdiction of the U.S. to approach, by any means, within 100 yd (91.4 m) of a humpback whale in any wate rs within 200 nmi of Alaska ( FR 66, No. 105, May 31, 2001). Vessels (with some exceptions) transiting near humpbacks also are required to adhere to a “slow, safe speed” requirement to prevent distur bance that could adversely affect humpbacks. Vessel interaction and approaches with fin whales and other listed marine mammals are subject to guidelines to meet the requirements of the ESA rather than species-specific regulation in

Alaskan waters.

Other Construction Activities

Island-construction activities could cause noise and disturbance to bowhead whales. Placement of fill material for island construction generally occurs during the winter, when bowhead whales are not present. Completion of island construc tion and placement of sl ope-protection materials may take place during the open-water season, but th ese activities generally are completed before the bowhead whale fall migration. Placement of sh eetpile, if used, would generate noise during the open-water period for one cons truction season but also should be completed in early to midAugust, before the whales migrate. Noise is not likely to propagate far due to the shallow water and the presence of barrier isla nds that, in many cases, may lie between the drilling location and the migration corridor used by bowhead whales, depending on the island location. Even during the migration, noise from these activities would be minor and would not affect bowhead whales.

If such construction were to occur in an area wh ere large numbers of whal es were attempting to feed (such as has been observed in a few year s (but not in many other years) in the Dease Inlet/Smith Bay area, the whales might be disp laced from a small portion of the feeding range for that year.

Preliminary analysis of noise measurements during the open-water construction season at Northstar Island by Blackwell a nd Greene (2001) indicated that the presence of self-propelled barges had the largest impact on the level of sound coming fr om Northstar Island. Selfpropelled barges remained at Northstar for days or weeks and always had their engines running,

85because they maintained their position by “pus hing” against the island. Sound measurements on a day when there were no self-propelled barges showed that sounds were inaudible to the field acoustician listening to the hydrophone signal beyond 1.85 km, even on a relatively calm day. By comparison, the sounds produced by self-prope lled barges, while limited in their frequency range, were detectable underwater as far as 28 km north of the island. Other vessels, such as the crew boat and tugs, produced qualitatively the same types of sounds, but they were present intermittently, and their effect on the sound environment was lower.

Summary of Potential Effects of Noise and Disturbance Sources

Available information indicates that baleen wh ales, and bowhead whales in particular, are responsive (in some cases highly responsive) to anthropogenic noise in their environment. At present, the primary response that has been docum ented is avoidance, sometimes at considerable distance. Response is variable, even to a particular noise s ource and the reasons for this variability are not fully understood.

Oil and gas exploration could re sult in considerable increase in noise and disturbance in the spring, summer, and autumn range of the Wester n Arctic bowhead whales, and to summering fin and humpback whales. This noise may result fr om various activities, including seismic, vessel traffic and icebreaker operation, drilling, and construction, and support ac tivities. Depending on their timing, location, and number, these activities potentially coul d produce sufficient noise and disturbance that whales might a void an area of high value to them and suffer consequences of biological significance. These consequences woul d be of particular concern if such areas included those used for feeding or resting by la rge numbers of individuals or by females and calves. In other species of mammals, including cetaceans, females with young are more responsive to noise and human disturbance th an other segments of the population.

If seismic operations overlap in time, the z one of seismic exclusion or influence could potentially be quite large, depending on the number, and the relative proximity of the surveys.

NMFS is concerned these simultaneous seismic activities could result in effects that are biologically significant, if they cause avoidance of feeding, re sting, or calving areas by large numbers of females with calves over a period of many weeks. The impact to individuals would likely be related to the importance of the food source or resting area to the component of the population that would have utilized it, had not the disturbance cau sed them to avoid the area. This is likely to remain unknown. Potential imp acts to the population w ould be related to the numbers and types of individuals that were affected (e.g., juvenile males versus females with calves). Activities that cause active avoidance over large distan ces may reduce the availability of any rest areas. Such areas may provide important energetic needs for bowheads during their autumn migration and other use of the Beaufort Sea. Less is cu rrently known of the habitat use and value of the action area for fin and humpback whales.

The observed response of bowhead whales to seismic noise has varied among studies. The factors associated with variability are not enti rely clear. However, da ta indicate that fall migrating bowheads show greater avoidance of active seismic vessels than do feeding bowheads. Recent monitoring studies (1996-199 8) and traditional knowledge indicate that during the fall migration, most bowhead whales avoid an area around a seismic vessel operating

86in nearshore waters by a radius of about 20 km and may begin avoidance at greater distances. Received sound levels at 20 km ranged from 117- 135 dB re 1 μPa rms and 107-126 dB re 1μ Pa rms at 30 km. This is a larger avoidance radi us than was observed from scientific studies conducted in the 1980’s. Avoidance did not pers ist beyond 12-24 hours after the end of seismic operations. In some early studies, bowheads also exhibited tendencies for reduced surfacing and dive duration, fewer blows per surfacing, and longer intervals between successive blows. Available data indicate that behavioral changes are temporary. Baleen whales respond to drilling noise at different distan ces depending on the types of platfo rm from which the drilling is occurring. Data indicate that many whales can be expected to avoid an ac tive drillship at 10-20 km or possibly more. The response of whales to construction in high use areas is unknown and is expected to vary with the site and the type of facility being constructed. Similarly, the longterm response of whales to produc tion facilities other than gravel islands located at the southern end of the bowhead migrat ion corridor is unknown.

Exploration will result in an increase in ma rine vessel activity, and depending on location and season, may include icebreakers, barges, tugs, suppl y and crew boats, and other vessels. Whales respond strongly to vessels direc tly approaching them. Avoidan ce of vessels usually begins when a rapidly approaching vessel is 1-4 km away, with a few whales possibly reacting at

distances from 5-7 km. Received noise levels as low as 84 dB re 1 μPa or 6 dB above ambient may elicit strong avoidance of an approaching ve ssel at a distance of 4 km. Fleeing from a vessel generally stopped within minutes after th e vessel passed, but scatte ring may persist for a longer period.

Icebreaker response distances va ry. Predictions from models indicate that bowhead whales likely would respond to the sound of the attending icebreakers at distances of 2-25 km, with roughly half of the bowhead whales showing avoi dance response to an icebreaker underway in open water at a range of 2-12 km when the sound-t o-noise ratio is 30 dB and roughly half of the bowhead whales showing avoidance response to an icebreaker pushing ic e at a range of 4.6-20

km when the sound-to-noise ratio is 30 dB. Whales appear to e xhibit less avoidance behavior with stationary sources of relatively c onstant noise than with moving sound sources.

Exploration also results in increa sed aircraft traffic, including possible whale monitoring flights. Most bowheads exhibit no obvious response to helicopter overflights at altitudes above 150 m (500 ft). At altitudes below 150 m (500 ft), some whales prob ably would dive quickly in response to the aircraft noise. Bowheads are relatively unaffected by aircraft overflights at altitudes above 300 m (984 ft). Be low this altitude, some changes in whale behavior may occur, depending on the type of plane and the responsiven ess of the whales presen t in the vicinity of the aircraft. Fixed-wing aircraft flying at low altitude often ca use hasty dives. Reactions to circling aircraft are sometimes conspicuous if the aircraft is below 300 m (1,000 ft), uncommon at 460 m (1,500 ft), and generally undetectable at 600 m (2,000 ft). The effects from such an encounter with either fixed-wing aircraft or helicopters generally are brief, and the whales

should resume their normal activit ies within minutes. If numerous flights for exploration or development and production occur (depending on the location) fin, humpback, and bowhead whales may be repeatedly exposed to helicopte r noise in areas between shorebases and/or airports and the production facili ties. Depending on where shorebas es for activities are located,

87effects could be mitigated by ensuring that flig ht paths avoided whale aggregations or that flights were high enough to avoid disturbance.

We anticipate that gravel islands are not likely to be constructed for explor atory drilling in most OCS waters, but that old artifici al islands might be used tempor arily. In the near future we expect that exploratory drilli ng in the Chukchi and Beaufort Sea will also be conducted from other platforms and during the open water peri od depending on water de pth, sea ice conditions, availability of drilling units, a nd the ice-resistance of units. Moveable platforms resting on the seafloor could be used to drill in water depths of 10-20 m, but drillships or other floating units would be used in deeper waster. Drilling from th ese units will be in open water. Such drilling would be supported by icebreakers and supply boats. This is expected to be the norm in the

Chukchi Sea.

If gravel islands were used for exploration dr illing, noise produced probably would not have large effects on bowhead or other whales, because gravel islands are constructed in fairly shallow water shoreward of the main migration route, and noise from operations on gravel islands generally is not audible beyond a few kilometers. In the Beaufort Sea, islandconstruction activities likely would be conducte d during the winter a nd generally are in

nearshore shallow waters shorewar d of the main bowhead whale mi gration route. However, as evidenced by Northstar, such construction was supported by numerous trips by barges and other vessels providing materials.

As development moves farther offshore, we anticip ate much greater aircraft and vessel support. For example, MMS estimates that marine transp ort requirements during construction in the Far Zone would range between 150- 250 vessel trips including numer ous barges during the open water period. Bowheads may exhibit temporary a voidance behavior if a pproached by vessels at a distance of 1-4 km (0.62-2.5 mi). Humpback wh ales are reported to avoi d vessels at distances of 2-4 km. Marine-vessel traffic also may in clude seagoing barges transporting equipment and supplies from Southcentral Alaska to drilling locations, most likely between mid-August and mid- to late September. Some fin, humpback, or bowheads may be disturbed by barge traffic. Fleeing behavior from vessel tra ffic generally stops within minut es after the vessel passed, but scattering may persist for a longer period. Given results from Northstar regarding noise from barges, and the reaction of bowheads to moving vessels, the level of barge and vessel activity that would occur if development and production proceeds as envisioned in the scenario could potentially cause bowhead whales to avoid the area between the production platform and docking facilities during the period of activity. The significance of such a potential effect would depend on where the producti on facility was located.

Overall, fin, humpback, or bowhead whales expo sed to noise-producing activities such as vessel and aircraft traffic, drilling operations, and seismic surveys most likely would experience temporary, nonlethal effects. Whale response to certain noise sources varies. Some of the variability appears to be context specific (i.e., feeding versus migrating whales) and also may be related to reproductive status a nd/or sex or age. As time goe s on, many of these activities can and probably will occur in both program areas in the same season and, in some cases, in closely adjacent areas. In 2008, 2D and 3D seismic su rveys, icebreaker activity for transit, high resolution surveys, and other support vessel traffi c are expected in the Beaufort Sea. Aerial

88surveys also may be conducted. In 2008, 2D and 3D seismic surveying, and high-resolution seismic surveys are anticipated in the Beaufort S ea and 2D and 3D seismic are anticipated in the

Chukchi Sea. If these activities are coincident in space and time, especially during migrations or in areas of aggregations, whales may be a dversely affected, including large numbers of

bowheads.

Data are sufficient to conclude th at all response to future noise a nd disturbance is likely to vary with time of year; sex and reproductive status of individuals exposed ; site (because of differences in noise propagati on and use by bowheads); activity a nd the exact characteristics of that activity (e.g., drilling versus seismic, air gun array and configurati on, etc.); the animal’s motivation to be in an area; and options for a lternative routes, places to feed, etc. While habituation is seen in some species, and beha vioral studies have suggested that bowheads habituate to noise from distant, ongoing drilling or seismic operations, lo calized avoidance still occurred. Bowheads may be less likel y to habituate to at least certa in types of noise than fin or humpback whales because they are hunted annually, and thus, many individuals may have a strong negative association with human noise.

The potential total adverse effects of long-term added noise, disturbance, and related avoidance of feeding and resting habitat in an extremely long-lived species such as the bowhead whale are

unknown. Available information does not indicate a ny long-term adverse effects on the Western Arctic stock from the high level of seismic su rveys and exploration dr illing during the 1980’s in the Beaufort and Chukchi seas. However, sub-le thal impacts on health (s uch as reduced hearing or increased stress) could not be detected in this population. The rate of this population’s

increase in abundance does not indi cate any sub-lethal effects (if they occurred) resulted in an effect on this population’s recovery. There ha s been no documented evidence that noise from previous OCS operations has served as a barr ier to migration. Because whales respond behaviorally to loud noise, they are less likely to suffer hearing loss from increased noise. However, whales appear to be more tolerant of noise when feeding, and future work is needed to determine potential effects on hearing due to lo ng periods over many years of exposure to loud noise at distances tolerated in feeding areas. Similarly, concern needs to be given to other potential physiological effects of loud noise, including the potentia l for increased noise to cause physiological stress responses.

We are not certain about the effects of multiple seismic surveys and other noise and disturbance sources over many years within areas which may be frequently used for feeding or resting by large numbers of whales. Concentrations of loud noise and disturbanc e activities during the open water period have the potential to cause large numbers of thes e whales to avoid using areas for resting and feeding for long periods of tim e (days to months) while the noise producing

activities continue. Because re cent data are not sufficient to evaluate current habitat use by season or area in the Chukchi Sea by bowhea d, humpback, or fin whales, we cannot fully estimate the consequence of indus trial noise on these species.

Effects from Discharges

Exploration drilling activity a nd other OCS exploratory actions would require the discharge of certain pollutants into th e receiving waters of the Chukchi and Beaufort Seas. The EPA must permit such discharges under their National Po llutant Discharge Elimination System (NPDES)

89program. The NPDES discharges are not part of this action, and EPA must consult with NMFS and USFWS on the effects of that program on listed species and critical habitat. However, the following discussion is presented to provide general information on these discharges and their potential affects.

There could be alterations in fin, humpback, or bowhead habitat as a re sult of exploration, including localized pollution and habitat destruction. Any poten tial adverse effects on these whales from discharges are directly related to whether or not any potenti ally harmful substances are released, if they are released to the marine environment, what their fate in that environment likely is (for example, different hypotheti cal fates could include rapid dilution or biomagnification through the food ch ain), and thus, whether they ar e bioavailable to the species

of interest.

Disposal of drilling muds and cuttings would be as specified under conditions prescribed by the EPA. Discharge of drilling muds and cuttings during exploration activitie s is not expected to cause population-level effects, e ither directly through contact or indirectly by affecting prey species. Any effects would be localized primarily around the drill rig because of the rapid dilution/deposition of these materials. Expl oration drilling muds and cuttings may cover portions of the seafloor and cause localized po llution. However, the effects likely would be negligible, because the areas of sea bottom that are impacted would be inconsequential in

relation to the available habitat.

Bottom-founded drilling units and/or gravel isla nds may cover areas of benthic habitat that support epibenthic invertebrates used for food by bowhead whales . Muds and cuttings from development drilling from platforms are expected to be treated and di sposed of in disposal wells, Muds and cuttings from satellite development wells are expected to be barged either to the host platform for downhole disposal or to shore for disposal. Produced waters are expected to be reinjected.

Gravel-island-construction activities, including placement of fill material , or installation of sheetpile or gravel bags for slope protection could cause loss of habitat, depending on the location of the gravel island. This construction would cause temporary sediment suspension or turbidity in the water as well as noise and di sturbance (see noise and disturbance section).

Potential Effects of Oil Spills from Exploration Activity The MMS estimates the chance of a large (> 1,000 bbl) oil spill from e xploratory activities to be very low. On the Beaufort and Chukchi Fede ral OCS, the oil industry drilled 35 exploratory wells. During the time of this drilling, indus try has had 35 small spills totaling 1,120 gallons (gal) or 26.7 bbl. Of the 26.7 bbl spilled, approx imately 24 bbl were reco vered or cleaned up. Small (1,000 gal or less) operationa l spills of diesel, refined fuel, or crude oil may occur. The MMS estimates this to be the ty pical scenario during explorator y drilling in the Beaufort and Chukchi seas. These small spills often are onto containment and gr avel islands or ice and can be cleaned up. No exploratory dril ling blowouts have occurred on the Arctic or the Alaskan OCS. Since 1971, industry has drilled approximately 172 e xploration wells in the Pacific, 51 in the Atlantic, 10,524 in the Gulf of Mexico, and 97 in Alaska, for a total of 10,844 wells (Brajas, Howard, and Monkelein 1999). From 1971-1999, th ere were 53 blowouts during exploration drilling. With the exception of three spills, 200, 100, and 11 bbl, respectively, no additional oil

90spills have occurred. Therefore, more than 13,000 wells have been drilled, and three spills resulted in crude reaching the environment durin g exploration.

Small spills are unlikely to ha ve significant effects on fin, humpback, or bowheads because of their reduced volumes and areas of impact and becau se it is anticipated that these whales will generally avoid exploration activit ies and, hence, not be in the im mediate vicinity at the time of a spill. Fuel spills associated with the ve ssels used during exploration activities could occur, especially during fuel transfer. There could be localized short-term alterations in habitat and habitat use as a result of such a spill. Whal es exposed to a small fuel spill likely would experience temporary, nonlethal effects. It is diffi cult to accurately pred ict the effects of oil on these whale species (or a ny cetacean) because of a lack of data on the metabolism of this species

and because of inconclusive results of examinatio ns of baleen whales f ound dead after major oil

releases.

Although there is no conclusive evid ence that large baleen whales w ould be killed as a result of contact with spilled oil, it is well documented that exposure of at least some mammals to petroleum hydrocarbons through surface contact, ingestion, and especially inhalation can be harmful. Surface contact with petroleum hydroc arbons, particularly the low-molecular-weight fractions, can cause temporary or permanent dama ge of the mucous membranes and eyes (Davis, Schafer, and Bell, 1960) or epidermis (Hansbr ough et al. 1985; St. Aubin 1988; Walsh et al., 1974). Contact with crude oil can damage eyes (Davis, Schafer, and Bell 1960). Ingestion of petroleum hydrocarbons can lead to subtle and progressive orga n damage or to rapid death. Inhalation of volatile hydrocarbon fr actions of fresh crude oil can damage the respiratory system (Hansen, 1985; Neff, 1990), cause neurological disorder s or liver damage (Geraci and St. Aubin 1982), have anesthetic effects (N eff 1990) and, if accompanied by excessive adrenalin release, cause sudden death (Geraci 1988).

Climate Change Climate change could potentially affect fin, humpback, or bowhead whales in several ways including:

* Increased noise and disturbance related to increased shipping, and possibly related to increased development, within their range;

* Increased interactions with commercial fisher ies, including increased noise and disturbance, incidental take, and gear entanglement;

* Decreases in ice cover with th e potential for resultant changes in prey species concentrations and distribution; * Related changes in whale distributions; * Changes in bowhead whale subsistence-hunting practices that could result in smaller, younger whales being taken and, possibly, in fewer whales being taken; * More frequent climatic anomalies, such as El Niños and La Niñas, wi th potential resultant changes in prey concentrations; and * A northern expansion of other whale species, with the possibility of increased overlap in the northern Bering and/or the Chukchi seas.

The potential effects of climate change on fin, humpback, and bowhead whales are uncertain.

There is no current evid ence of negative effects on the whales . There is no evidence suggesting

91that many of the changes that coul d occur, such as changes in timi ng of migrations and shifts in distribution, would be associat ed with overall adverse effect s on these whales. Conceptual models by Moore and Laidre (200 6) suggested that reductions in sea ice cover should increase the Bering-Chukchi-Beaufort Sea stoc k of bowhead whale prey availab ility. In Shelden et al.’s (2003) response to Taylor’s statem ents regarding the expectation of future downward trends in abundance based on what he termed “available evidence” regarding climate change, they point out that Taylor did not provide ci tations supporting this claim. Sh elden et al. (2003) state that: Although available data do indicate that the Be ring Sea environment is changing (e.g., Angel & Smith 2002), we are aware of no evidence that envi ronmental changes will be detrimental to the population in the foreseeable future. In fact, our review...on this issue suggests that climate change may actually result in more favorable conditions for Western Arctic bowheads.

This theory may be substantiated by the st eady increase in the BCBS population during the nearly 20 years of sea ice reductions (Walsh 2008). Moore and H untington (2008) anticipate that bowhead whales will alter migration routes and occupy new feeding areas in response to climate related environmental change. Sheldon et al. (2003) notes that there is a high probability that

bowhead abundance will increase under a warmi ng global climate. Bluh m and Gradinger (2008) state new pelagic feeding grounds may open up to Arctic marine mammals and subarctic marine mammals in high Arctic basins, while nearshor e areas may provide less abundant food in the future due to increased precipitation, river run-o ff, lowered salinities, and increasing turbidity.

The recent observations of humpback whales in the Beaufort and Chukchi seas may be indicative of seasonal habitat expa nsion in response to receding sea ice or increases in prey availability which these whales now exploit. Range expansions in response to habitat change

are not uncommon among cetaceans. Gray whales in Alaska have shown pronounced change over the last several decades; overwintering at hi gher latitudes and occupying previously lesserused feeding areas in the Beaufort Sea. Concentrations of th e rare North Pacific right whale

were first observed in 1996 and have conti nued until recently, possible reflecting changes in zooplankton distribution due to large-scale o ceanographic change within the Bering Sea.

New information regarding humpback whale occu rrence in the Chukchi Sea and Beaufort Sea Planning Areas are limited to data from mari ne mammal monitoring in 2006 and 2007 whale. This limited and low intensity sampling is insufficient to make reliable predictions about the effect of arctic climate change on humpback whal es. We cannot rule out that recent changes in humpback distribution may be due in part to climate change phenomena. Since humpback and fin whales are not ice-obligate or ice-associated species, it is unknown how long this habitat will remain viable for these species. However, it is logical to assume these whales will continue to utilize these waters as long as th e availability of prey remains.

We emphasize that there is uncertainty associated with many of the pred ictions about potential climate changes, especially at a regional level, and associated environmental changes that could occur. However, if this cha nge occurs, it is likely that sh ipping would increase throughout the range of fin, humpback and bowhead whales, especi ally in the Chukchi and southern portions of

the Beaufort Sea. If commercial fisheries were to expand into the Chukchi or Beaufort Sea, fin, bowhead, or humpback whale death and or injury due to interactions with fishing gear, possibly injury and/or death due to inci dental take in commercial fish eries, and temporary effects on

92behavior potentially could occur. There are, however, few data that would permit us to quantitatively predict such types of effects. The North Slope Borough Department of Wildlife

has examined harvested bowhead whales and fo und 0% to 33% of those displayed line wounds indicative of fishing gear inter action. Humpbacks in southeastern Alaska interact with various fishing gear, notably set gill nets an d pot gear in nearshore areas.

Tynan and DeMaster (1997) note an earlier IPCC report that conc luded that an increase in human activity is likely to accompany the opening of the Northwest Passage and the Russian Northern Sea Route. They identify a poten tial for increased envi ronmental pollution, an increased incidence of epizootics, exploration, increased ship traffic, increased fisheries, and increased industrial activities, and the synergis tic effects of these factors with ecosystem changes due to climate change as potential conc erns for marine mammals populations. Perhaps the greatest potential adverse e ffect associated with global wa rming could occur if predictions that the Northwest Passage may become ice free for significant lengths of time prove accurate, opening sea routes across the Beaufort Sea and a Northern Sea Route along the Russian north coast and increasing shipping in parts of the range of the WNPS of humpback, fin and bowhead

whales.

The Office of Naval Research (2001) reported that climate warming in the Arctic is likely to result in the northward migrati on of subarctic species of marine mammals and an increase in commercial-fishing activities into the Chukchi an d Beaufort seas, where operations have been minimal in the past. If substantial increases in shipping were to occur that placed more ships in waters inhabited by humpback whales, increases in adverse effect to them also might occur due to shipping-related noise and di sturbance, vessel strikes, and pollution. Quantification of such potential changes are not possible at this time due to the level of uncertainty about changes that might occur over the course of the proposed proj ect and the shipping industry’s response to greater cross-Beaufort transiting oppor tunities, when they do occur.

We conclude that the potential effects of climate change on humpback whales, fin whales, or

bowhead stock in Alaska are uncertain. Th e NMFS’ National Marine Mammal Laboratory has

stated there are insufficient data to make reliabl e predictions of the effects of Arctic climate change on bowhead whales (Angliss and Outlaw 2008) . There is no current evidence of adverse effects on these whales due to climate change. There is no documented evidence suggesting that many of the changes that could occur, such as changes in timing of migrations, shifts in distribution, shifts in migration routes, and shifts in abundance a nd distribution of prey would be associated with overall adverse or positive effects on these whales. The occurrence of fin and humpbacks in the Chukchi and Beaufort seas in 2006 and 2007 may be ini tial indications that habitat conditions may be changing that favor humpback whales pioneering new summer ranges; however, the short duration of observations is insufficient to conclude whether the recent observations indicate an anomaly or a trend. We remain concerned that increasing shipping and industrial activity associated with arctic warming will occur. This increase in noise and

disturbance will be in addition to the levels of noise from curre nt industrial activity, subsistence harvest activities, local/regional shipping, research, recreational, military, aircraft, and other

vessel traffic.

V. CUMULATIVE EFFECTS

93Cumulative effects are define d in 50 CFR 402.02 (Interagency Cooperation on the ESA of 1973, as amended): “...those effects of future Stat e or private activities not involving Federal activities that are reasonably certain to occur w ithin the action area of the Federal action subject

to consultation.” Reasonable foreseeable future federal actions and pot ential future Federal actions that are unrelated to the proposed action are not considered in the analysis of cumulative effects because they would require separate c onsultation pursuant to s ection 7 of the ESA. Cumulative effects are usually viewed as those ef fects that impact the existing environment and remain to become part of the environment. These effects differ from those that may be attributed to past and ongoing actions within the area since they are consider ed part of the environmental baseline. Additionally, most structures and ma jor activities within th e Chukchi and Beaufort Sea OCS require Federal authorizations from on e or more agencies, such as the MMS, Army Corps of Engineers, and the Environmental Pr otection Agency. Such projects must consult

under the ESA on their effects to the bowhead whal e, and are therefore not addressed here as cumulative impacts.

The State of Alaska is currently leasing State-ow ned portions of the Beaufort Sea for oil and gas exploration and production. No sales have occu rred nor are planned for the Chukchi Sea by the

State. The current State of Alaska Five-Year Oil and Gas Leasing Program published in January

2006 lists Beaufort Sea area wide sales continuing in Octobe r 2006-2010. The State is currently conducting a “b est interest finding” in anticipat ion of leasing over the period 2009- 2019. The proposed sales consis t of all unleased tide and submerged lands between the

Canadian Border and Point Barrow as well as some upland acreage. If any of the scheduled sales occur, additional effects similar to those described for OCS lease sales could occur. All producing fields on the North Sl ope are onshore and on State leas es, with the ex ception of the Duck Island Unit (which contains the Endicott fi eld). Endicott is on State leases and was the first offshore production facility developed in th e Beaufort Sea. Endicott has been producing oil since 1987. Endicott is located on a manmade grav el structure inside the barrier islands in relatively shallow water. Suppor t traffic is over a gravel cause way that also contains the pipeline to shore. New production islands in St ate waters now include Northstar Island near Prudhoe Bay, and Oooguruk and Nikaitc huq Islands off Harrison Bay.

Oil and gas development is also underway in the Eastern Beaufort Sea off the Canadian Mackenzie Delta. This includes seismic survey s, drilling, and infrastructure and support

facilities as described for the US OCS. Seis mic programs have recently been conducted off the

Mackenzie Delta.

Bowhead whales may be disturbed during the summer in the Canadi an Beaufort Sea, if offshore oil and gas exploration and development and producti on activities occur there in the future. The main area of industry interest to date has centered around the Mackenzie River Delta and offshore of the Tuktoyaktuk Peninsula. There has been little industry acti vity in this area in recent years, and we are not aware of any propos ed activities. This area comprises a minor portion of the bowhead’s summer range. Possi ble disturbance to bowhead whales from helicopters, vessels, seismic surveys, and dr illing would be as previously described.

Since offshore oil and gas activities in State waters are generally well shoreward of the bowheads’ main migration route, and some of the activities occur inside the barrier islands, the

94overall effects on bowheads from activities on Stat e leases is likely to be minimal. These impacts could be magnified, however, if construction activity associated with additional development projects were to occur simultaneousl y, rather than consecutively. For example, construction and drilling noise from multiple dril ling sites could result in a long-term, offshore shift in bowhead migration routes. The extra distance and heavier ice encountered could result in slower migration or physiological stress that may noticeably affect the whales. However, the majority of bowhead, fin and humpback whales are generally found offshore of State waters.

Some effects on bowhead, fin and humpback whales may occur because of activities from lease sales within State waters (within 3 miles of s hore). Generally, bowhead whales remain far enough offshore to be found mainly in Federal wate rs, but they may occur in State waters in some areas, such as the Beaufort Sea southeast and north of Kaktovik an d near Point Barrow. Presumably, fin whales in these areas also re main far enough offshore to be found mainly in Federal waters. Humpback whales, however, are largely nearshore feeders and are most often found in State waters throughout southeast and s outhcentral Alaska, as well as the Aleutian Islands. Given the minimal sighting data for hum pback whales in the Arctic, it is difficult to predict whether the species would be found primarily in Federal or State waters in this region.

If exploration and development and production ac tivities occur on leases from previous or proposed State sales, noise effects on whales may occur as described previously. These effects could include behavioral respons es, including local avoidance to noise from aircraft and vessel traffic; seismic surveys; explor atory drilling; construction acti vities, including dredging; and development drilling and production operations that occur within several miles of the whales.

Future exploration and development within th e Canadian Beaufort would present concerns beyond those associated with leasing in the Alas kan Beaufort Sea. The main area of industry

interest has been the Mackenzie Delta and offs hore of the Tuktoyaktuk Peninsula (MMS 1995). The large estuarine front associated with the Mackenzie Delta and upwellings near the Tuktoyaktuk Peninsula provide conditions whic h concentrate zooplankton (Moore and Reeves 1993). These areas are important feeding habitat to the Bering Sea bowhead stock. There are no reported plans for oil and gas exploration or produc tion within the Canadian Beaufort Sea at this time, however, and this activity would not be considered reasonably expected to occur.

Current State leases with production, such as Endicott, Oooguruk, and Nikaitchuq, are well removed from the normal fall migration route of the bowhead whale. Bowhead whales are not likely to be affected by noise from the these pr ojects due to their distance from the bowhead’s fall migration route and the limited distance into th e marine environment that noise travels from gravel structures.

Each of the projects described would require so me equipment and supplies to be transported to the site by barge or sealift should developmen t and production plans proceed. The process modules and permanent living quarters and othe r equipment and supplies likely would be transported to these sites on seagoing barges dur ing the open-water season. Barge traffic around Point Barrow is likely to be limited to a s hort period from mid-A ugust through mid-to-late September and should be completed before th e bowhead whale migration reaches this area unless it encounters severe ice conditions. Barge traffic continuing into September is likely to

95disturb some bowheads during thei r migration. Whales may react briefly by diving in response to low-flying helicopters and they would seek to avoid close approach by vessels. Oil spill probabilities associated with expl oration are extremely low. In the event an oil spill occurred on State leases during the fall bow head migration, or during the presence of fin and humpback whales, the effects of an oil spi ll on these whales would be as have been described earlier in this

document. These effects include inhalation of hydrocarbon vapors, a loss of prey organisms, ingestion of spilled oil or oil- contaminated prey, baleen foul ing with a reduction in feeding efficiency, and skin and/or sensory organ da mage. These effects would be most pronounced

whenever whales were confined to an area of freshl y spilled oil. Of course , if the spill occurred over a prolonged period of time, more individuals could be cont acted. Some individuals could be killed as a result of prolonged contact with freshly spilled oil, particularly if spills were to occur within ice-lead systems.

Activities that are not oil and gas related also affect bowh ead, fin and humpback whales. Between 1976 and 1992, only three ship -strike injuries were docum ented out of a total of 236 bowhead whales examined from the Alaskan subsistence harvest (George et al., 1994). The low number of observed ship-strik e injuries suggests that bowhead s either do not often encounter vessels or they avoid interactions with vessels, or that interactions usually result in the death of the animals. However, there is recent evidence that interaction of bowhead whales with ships and fishing gear may be increasi ng. Evidence also exists for ship strikes of fin and humpback whales by both small and large tonnage vessels in Southeast and Southcentral Alaska. As the population of humpback whales continues to reco ver, the species’ growing abundance will likely result in a greater probability of interactions with ships and fisheries.

Subsistence harvest by Alaska Natives is anot her non-OCS activity that affects the bowhead whale, although not the fin or humpback whale as neither of these species is taken for

subsistence use. Bowheads are taken in the northern Bering Sea and in the Chukchi Sea on their spring migration and in the Beaufort Sea on their fall migration. Barrow whalers harvest whales during both the spring and the fall migrati ons. Requests to harvest bowheads also have been made by Canadian and Russian Natives. The Canadian Government granted permission in 1991 to kill one bowhead, and a bowhead was harv ested in Mackenzie Bay in the fall of 1991. Additional permits were granted in 1993 and 1994, but no bowheads were harvested in either year. There has been a renewed interest by vill ages along the Russian Chukchi Sea coast to hunt bowhead whales. At the 1997 IWC, the Comm ission approved a combined quota allowing an average of 56 bowheads to be landed each year to meet the needs of Eskimos in Alaska and Chukotka Natives of the Russian Far East. The annual number of bowheads landed by Alaskan Natives has ranged from 8 in 1982 to 55 in 2005 (U SDOC 2008). Struck- but-lost figures have

been between 5 in 1999 to 82 in 1977.

There currently is a 5-year block quota of 280 bowhead whales landed, authorized by the IWC

for 2008-2012. The number of bowheads struck in each year may not exceed 67, except that any unused portion of a strike quota from any year may be carried forward. No more than 15 strikes may be added to the strike quota for any one y ear. This level of harvest was approved by the IWC under the supposition that it still would allow for conti nued growth in the bowhead population. It is likely the bowhead whale population will con tinue to be monitored and that harvest quota will be set accordingly to ma intain a healthy bowhead population level.

96The cumulative effects of noise on bowheads, fins, and humpbacks from offshore oil and gas

activities would be similar to that described and summarized fo r OCS leasing and exploration. The effects from an encounter with aircraft ge nerally are brief, and the whales should resume

their normal activities within minutes. Bo wheads and humpbacks may exhibit temporary

avoidance behavior to vessels at a distance of 1-4 kilometers . Fleeing from a vessel generally stopped within minutes after the vessel passed, but scattering may pers ist for a longer period.

Bowheads also exhibited tendencies for reduced surfacing and dive duration, fewer blows per surfacing, and longer intervals between successive blows. Bowheads appear to recover from these behavioral changes within 30-60 minutes following the end of seismic activity. However, recent monitoring studies indicate that bowhead whales during the fall migration avoid an area around a seismic vessel operating in nearshore wa ters by a radius of about 20 kilometers. Avoidance did not persist beyond 12 hours after the end of seismic operations. This work also stated that bowhead whales may begin to defl ect around a seismic source at distances up to 35

km.

Bowheads have been sighted within 0.2-5 k ilometers from drill ships, although bowheads change their migration speed and swimming direc tion to avoid close approach to most noiseproducing activities. Bowheads may avoid drilli ng noise at 20-30 kilometers. There are no

observations of bowhead reactions to icebreakers breaking ice, but it has been predicted that roughly half of the bowheads would respond at a distance of 4.6-20 kilometers when the S:N is 30 dB. Overall, bowhead whales exposed to noise-producing activit ies most likely would experience temporary, nonlethal effects. Some a voidance behavior could persist up to 12 hours.

Some whales could be exposed to spilled oil, resulting in temporary, nonlethal effects, although some mortality might result if there were a prolo nged exposure to freshly spilled oil. Overall, whales exposed to noise-producing activities and oil spills associated with the proposal and other future and existing projects within the Arctic region—comb ined with the other activities within the range of these whal es—most likely would experience temporary, nonlethal effects. However, exposure to oil spills coul d result in lethal effects.

Vessel traffic and, perhaps, aircraft activity may be expected to occur in the future in both the

Chukchi and Beaufort Seas. The effects of these actions would be the same as that presented for traffic associated with oil and gas actions. NM FS is aware of speculation that warmer ocean temperatures associated with climate change ma y allow for increased commercial fishing in the Chukchi Sea. However, we have no further in formation which would substantiate or quantify such development.

VI. CONCLUSIONS This Biological Opinion has considered the effect s of the oil and gas l easing and exploration on the Outer Continental Shelf portion of the U.S. C hukchi and Beaufort Seas on the fin, humpback and bowhead whale. These actions are likely to adversely affect these whales due to vessel operations, marine geophysical (sei smic) exploration, aircraft tra ffic, and drilling noises from various structures. The probability of a large oil spill is remote duri ng exploration, but spill probabilities may be significan t during latter phases.

97Elevated noise levels in the marine environment could alter the hearing ability of whales, causing temporary or permanent threshold shif ts. However, information suggests most continuous and impulsive underwater noise levels would be at le vels or durations below those expected to injure hearing m echanisms. Nonetheless, marine seismic activities may present concerns with respect to hearing, and should be closely conditioned and monitored to avoid

these effects. Noise has also been shown to cause avoidance in migrating gray and bowhead whales. Seismic geophysical surveys and the possible use of ice breakers to support OCS activities present the highest probability for avoidan ce of any of the activities associated with oil exploration. Studies have shown noise from ice breakers may be detected at distances exceeding

50 km. It is reasonable to assume that bowheads could also detect this noise at this distance, however the distance at which bowheads may r eact to such noise is poorly described.

Available data do not indicate that noise and disturbance from oil a nd gas exploration and development activities since the mid-1970s had a lasting population-level adverse effect on

bowhead whales. Data indicate that bowhead wh ales are robust, increasing in abundance, and have been approaching (or have r eached) the lower limit of their historic population size at the same time that oil and gas expl oration activities have been occurring in the Beaufort Sea and, to a lesser extent, the Chukchi Sea.

Although reliable estimates for the North Pa cific fin whale populati on are currently not available, Zerbini et al. (2006) estimated rates of increase of fin whales in coastal waters south

of the Alaska Peninsula and found a rate of in crease of 4.8% (95% CI: 41.-5.4%) for the period 1987-2003 (Angliss and Outlaw 2008). This estimate is consistent with the population growth rate of other large whales. A recent annual abundance estimate for th e entire North Pacific population of humpback whales (Central, Eastern, and Western) was 6,010 animals (Calambokidis et al. 1997), with the best available estimate of the current rate of increase for the Central North Pacific population acknowledged as 7% per year (Angliss and Outlaw 2008). However, new data revealed by the SPLASH research effort (Structure of Populations, Levels of Abundance and Status of Humpback Wh ale Stocks), initiated in 2002 and involving more than

400 researchers from 10 nations , indicates that current popula tion levels for North Pacific humpback whales have rebounded to 18,000-20,000 individuals (NMFS 2008). Given these data, there is no indica tion that noise and disturbance fr om oil and gas exploration and development activities since the mid-1970s had a lasting population-level adverse effect on either fin or humpback whales.

Research on the effects of offshore seismic e xploration in the Beaufort Sea, supported by the testimony of Inupiat hunters based on their own experience, has shown bowhead whales avoid these operations when within 20 km of the source and may begin to deflect at distances up to 35 km (Richardson, 1999a). Davies (1997) conclude s bowheads avoided an ac tive drilling rig at a

distance of 20 km. While such deflections duri ng migration may not be injurious to individual animals, concern is warranted for cumulative noise and multiple disturbance; the consequences of which might include long-term shifts in mi grational paths or displacement from nearshore feeding habitats. However, it is unlikely that even these impacts would prevent the survival and recovery of this species, as th e primary feeding habitat is considered to be in the Canadian Beaufort and, perhaps, the Bering Sea (Shell, 19 98.). It can be assume d that these impacts

98would also have an insignificant impact on the survival and recovery of both fin and humpback whales, as their current primary distribution and feeding habitat re mains farther south. To date, concentrations of humpback and fin whales have not been observ ed in the Beaufort or Chukchi

Seas.

The Alaskan Beaufort Sea certainly provides f eeding habitat for bowhead whales, however the importance of this habitat is not fully studied at this time. Similarly, current data do not fully identify the importance of the Chukchi Sea to fi n, humpback, or bowhead whales (it is known to be important as a migrational corridor for bowh eads). Concern is warranted over the distribution in time and space of several noise-producing activiti es. The most potentially disruptive of these would be seismic operations, with the potential to deflect whales at a distance of 30 km. It may be prudent, then, to avoid creating an acoustic gauntlet caused by multiple operations in a common area by requiring minimum separations between operations. We offer a Conservation Recommendation regarding this concern. Such eff ect is at least partially mitigated by the activity itself; all but very small operations w ould have to avoid other seismic signals by 15 miles (24.1 km) to eliminate interference from th at signal. Additional mitigative measures are offered (see Conservation Recomme ndations). Because of the poten tial for noise disturbance to displace whales from important feeding areas, sp ecial scrutiny should be given to seismic and drilling operations which may impact these areas . While many feeding areas are dynamic and may change location from year to year, Nativ e hunters have reported the Kaktovik area as a traditional feeding area for bowheads.

Consideration of the potential impacts of oil spil ls to the fin, humpback, or bowhead whale must assess 1) the probabilities for a spill to occur and to make contact with the whales and/or their habitat, 2) the effects of oil spills and spill responses on these whales, and 3) the ability of industry to prevent, control, and recover spille d oil. Should a spill occur, its effects to these whales would depend on factors su ch as the time and location of the spill, the nature of the product spilled, its persistence a nd toxicity, and the effectiveness of any response measures. The estimated physical and behavioral effects of an oil spill on fin, humpback, or bowhead

whales have been described. While it is clear additional research is needed to assess these

effects and that no consensus has been reached regarding the degree to which oiling might impact the whales, we believe that whales contac ting oil, particularly freshly-spilled oil, could be harmed and possibly killed. Additionally, an oil spi ll reaching into the spring lead system has the potential to impact a significant number of bo wheads. Several coincidental events would be necessary for this scenario; the spill would have to occur, the spill would have to coincide with

the seasonal occurrence of whales in these waters , the spill would have to be transported to the area the whales occupy (e.g. the migrational corri dor or spring lead system), and clean-up or response efforts would have to have been at least partially unsuccessf ul. The impact of such an event would be significant, yet the probability fo r the coincident occurrence of these events would be low. It must also be recognized that the spring lead system is not static, as leads open and close and whales navigate not only through the leads but surrounding ice (Clark and Ellison, 1988). Because of this it is often difficult to asse ss the potential effects of exploration within the spring lead system.

The ability to prevent, identify, locate, contain, a nd remove spilled oil is a significant concern. NMFS believes that, while spills represent low-pr obability events, their biological impacts are

99significant and that the operator should make ever y reasonable effort to meet these challenges. We are especially concerned withthe ability to contain and rem ove or recover spilled oil under broken or newly-forming ice conditions. Spill response drills have failed to demonstrate industry can adequately respond under these co nditions in the Beaufort Sea (ADEC, 2000). Similarly, spill response protocols, technologies, plan s, or infrastructure to respond to spills in the Chukchi Sea are not fully developed or untes ted. While oil spills ar e not expected during exploration, we believe MMS must recognize this failing, and take actions prior to later phases of development which task industry to develop effective response capabil ities during all possible conditions and spill scenarios, and that each operator is held to strict standards to further reduce any likelihood of oil spills.

Because the Western Arctic bowhead whale popul ation is approaching its pre-exploitation population size and has been documented to be in creasing at a roughly cons tant rate for over 20 years, the impacts of oil and gas industry on in dividual survival and reproduction in the past have likely been minor (Angliss and Outlaw 2008). These activities are unlikely to have any

effect on the other four stocks of bowhead wh ales. Similarly, only the western North Pacific stock of humpback whales and the Northeast Paci fic stock of fin whales would be potentially affected by oil and gas leasing a nd exploration activities in the Chukchi and Beaufort Seas. The

described work would have no effect on the rema ining worldwide stocks of humpback or fin whales. No lethal takes are anticipated because of these activities, nor are population-level consequence to the stocks expected. Most impact would be due to harassment of whales, which may lead to behavioral reactions from which recovery is fairly rapid. Mitigative measures will be recommended to reduce harassment and the po ssibility of harm or lethal takes.

After reviewing the current status of the fin, humpback, and bowhead whale, the environmental baseline for the action area, the biological and physical impacts of oil leasing and exploration, and cumulative effects, and in consideration that the described actions are expected to impact only a single stock of each of these endangered whales, and not the species as a whole, it is NMFS’s biological opinion that oil and gas leasing and exploration in the Chukchi and Beaufort Seas, and authorization of small takes under the MMPA, are not likel y to jeopardize the continued existence of the endangered fin, humpback, or bowhead whale. No critical habitat has been designated for these species ; therefore none will be affected.

VII. INCREMENTAL STEP CONULTATION This opinion addresses the increm ental step of MMS leasing and e xploration actions in the U.S. Chukchi and Beaufort Seas. For the MMS to pro ceed with the incremental step, there must be a

reasonable likelihood the entire action will not violate section 7 (a)(2) of the ESA (50 CFR 402.14(k)). Therefore, NMFS is providing its views on the subse quent phases of development and production, should commercially-via ble discoveries of oil occur.

Development and Production Scenario

If commercial quantities of oil are discovered and development and production proceed, gravel island construction/platform installation and pi peline construction activ ities would occur. Activities during development and production, li ke those occurring during exploration, will

100result in noise, altered habitat, and adverse effects on behavior, distribution, and abundance of individuals or populations occurring in or adj acent to the sale area. In addition, cleanup activities associated with any oil spill may result in disturbance.

Oil or other petroleum products released duri ng development or production may cause adverse

effects on individuals either thr ough direct contact or indirectly as a result of effects on prey populations or important habitats. Contaminants, ot her than crude oil, such as drilling muds and cuttings, are not expected to cause significant eff ects, because they are likely to become rapidly diluted near the point of release. Moreover, the Environmental Protec tion Agency’s discharge permits may require re-injection of muds and cuttings whenever possible, eliminating these discharges. The Northstar pr oject has been so designed.

Noise effects associated with development and production ac tivities on endangered whales

would be similar to those described earlier. Whales would exhibit a voidance behavior from

noise associated with aircraft traffic, supply vessels, barge traffic, icebreakers, drilling operations or seismic-survey vessels. Whales may temporarily interrupt their activities and swim away from the vessel’s path. In most cases such behavioral changes last from minutes to

as much as an hour. Avoidance movements around a stationary noise source such as a production platform could require several hours . Recent studies on the effects of seismic operations on bowheads indicate the avoidance beha vior may persist for as much as 12-24 hours.

As stated earlier, underwater i ndustrial noise, including drilling noi se, measured from artificial gravel islands, has not been audible in the wate r more than a few kilometers away. Because the bowhead whale’s main migration corridor is 10 kilometers or more seaward of the barrier islands (and future humpback and fin whale pres ence is largely unknown for this area), drilling and production noise from inside the barrier isla nds may not reach many migrating whales. It also likely would not affect the few whales that may be in lagoon entrances or inside the barrier islands because of the rapid at tenuation of industrial sounds in a shallow-water environment.

Marine-vessel traffic outside th e barrier islands probably would include only seagoing barges transporting equipment and supplies from South central Alaska, most likely between mid-August and mid-to-late September. Barge traffic contin uing into September is likely to disturb some bowheads during their migration. Whales would a void being within 1-4 k ilometers of barges. Fleeing behavior usually stops within minutes af ter a vessel has passed but may last longer.

Vessels and aircraft inside th e barrier islands should not a ffect bowhead, fin or humpback

whales.

Offshore production within the normal fall migrati on route of the bowhead whale is likely to

disturb some bowhead whales on their fall mi gration. Marine-vessel traffic probably would include, but not be limited to, seagoing barg es transporting equipment and supplies from Southcentral Alaska to the location, most likely between mid-August and mid- to late September. Barge traffic continuing into Septem ber is likely to distur b some bowheads during their migration. Whales would try to avoid close approach by vessels . Aircraft traffic, such as helicopters from Deadhorse, would cause bowhead s to dive if they pass low overhead. We do not have enough evidence to know whether or not industrial activity fo r several years would keep bowheads, fins or humpbacks from using an area, although abandonment of feeding habitat is a significant concern.

101There would be additional noise -producing activities such as dr edging (trenching) for pipeline construction. Dredging or trench ing may be used in constructing the gathering pipeline from the production platform to shore. Bowhead reactions to dredge noise have been observed to be similar to their reactions to drilling noise, includi ng avoidance of the near vicinity of the activity. In one instance, as many as 12 bowheads were obs erved within 5 kilometers (3 miles) from active dredging operations on th eir summer-feeding grounds. Ho wever, some bowheads were detected within 800 meters (2,625 feet) of th e site (Richardson and Malme 1993). Dredge sounds were well above ambient levels up to se veral kilometers away (22 dB above average

ambient level at 1.2 kilometers [0.75 miles] from the dredge). In other instances, bowheads were observed at distances where they were well within the ensonifi ed area of dredging operations. However, in playback experiments, some whales responded to the onset of similar levels of dredge noise by exhibi ting weak avoidance. Bowheads s een in the vicinity of actual dredging operations may have habituated to the activity, or there may be variation among bowheads in the degree of sensitivity toward noise disturbance, so that bowheads seen in the vicinity of dredging operations may have been th e more tolerant individuals. Noise from these activities may cause whales to avoid the immedi ate vicinity of the pipeline construction and platforms. It is likely that the area of avoi dance would be relatively small, because whales appear to exhibit less avoidance behavior with stationary sources of relatively constant noise than with moving sound sources. Dredging activ ities may occur during the winter through the ice and therefore, would not aff ect bowheads, fins or humpbacks.

Cleanup activities associated with an oil spill, other than during winter, are likely to result in disturbance to whales. If an oil spill does occur, it is likely that la rge numbers of personnel, vessels, and aircraft will be present and conducting cleanup op erations in the Chukchi or Beaufort Sea. If spilled oil is present duri ng the bowhead whale migration, it could result in disturbance and possible displacement of whales from their normal migration route. Response actions may also cause fin, humpback, and bowhead whales to abandon feeding areas. Disturbance effects are expect ed to persist for the durati on of cleanup operations if the operations are conducted during the summer or fa ll period. The effects of oil spills on fin, humpback, and bowhead whales have been discussed previously in this document.

Development within the spring lead system may be limited by current technology. However, any such activity within this area of the Chukc hi and Beaufort Sea presents several unique and unanswered concerns with respect to these whales. Operation in relatively deep waters subject to heavy ice is likely to require ice management . The drilling structure alone may cause springmigrating bowheads to deflect around the source, po ssibly into the pack ice if other leads are not

available. While Eskimo hunter s have often observed that bow head whales can travel through ice, breaking ice up to a foot or more in th ickness, other smaller whales and calves may be unable to do so. Additionally, any oil spills with in the spring lead system would be detrimental to the migrating bowheads, and would present the pot ential to impact a sign ificant percentage of

the stock.

We are not, and we cannot be, certain of the leve l of effects on endangered whales should a large or very large oil spill occur. Should deve lopment and production occu r in the Chukchi Sea OCS, the estimated chance of spills >1,000 bbl o ccurring in the Chukchi Sea OCS is estimated

to be about 40%. The estimated chance of one or more 1,000-bbl spil ls occurring in the

102Beaufort Sea OCS is about 10-11%. Oil spil led in the Beaufort Sea OCS could contact

resources in the Chukchi Sea OC S and vice versa. Thus, hum pback, fin and bowhead whales could conceivably be exposed to oil and oil spill response from spills in either planning areas. The estimated chance of one or more large spills occurring, based on lease sa les in both areas, is

47%.

Adult whales exposed to spilled oil likely w ould experience temporary, or perhaps permanent, nonlethal effects, although prolonged exposure to freshly spilled oil could kill whales. This conclusion is supported by the best available in formation. There are no available data that definitely link a large oi l spill with a significant population-le vel effect on a species of large

cetacean.

• However, while data from previous spills in other locations worldwide are broadly informative, we acknowledge uncertainty abou t the potential for population level effects or other potential outcomes should a large or very large spill occu r in instances where whales are aggregated and/or constrained in their option for alternative routes (for example, in the spring lead and polynya syst em due to ice conditions) or are aggregated in a feeding area, especially if aggregations contained large numbers of females and calves. The potential for a population level e ffect may exist if large numbers of females and calves, especially newborn or very young calves, were to be contacted by large amounts of freshly spilled oil.

Well Abandonment On completion of production, wells would be ab andoned and sites rehabilitated as may be required by the MMS. Noise, disturbance, and po ssible injury to threatened and endangered species during OCS oil and gas exploration ar e activities associated with abandonment of exploration and delineation wells. The casings for wells can be cut mechanically or with explosives during the process of well abandonment. The use of expl osives could result in injury

or even death to whales that are in the area at the time of the explosions, although the threshold levels for injury or death are not well esta blished (for example, Ketten, Lien and Todd, 1993; Richardson et al., 1995). With respect to we ll abandonment, the MMS (USDOI, MMS, Pacific OCS Region, 2001) previously summarized that:

...the use of explosives for delineation well abandonment would involve the detonation of a relatively small, 16- to 20-kilogram charge in the well casing 5 meters below the sea floor. This positioning of the charge would dampen the expl osion and restrict shock and acoustic effects primarily to the area of water immediately abov e the well head. However, a marine mammal close to the detonation site po tentially could be injured or killed, or suffer permanent or temporary hearing damage. Some disturbance of marine mammals present in the vicinity of the detonation area could also occur, but thes e would be expected to be minor and temporary...Overall, impacts from this source are expected to be low

.

Impacts to whales from well-abandonment activiti es could be avoided if these activities were implemented only when fin, humpback, and bowhead s were absent or if sufficient monitoring (e.g., aerial surveys and passive acoustic monitori ng) for bowheads occurred prior to the use of any explosives and protocols were implemented to ensure that such explosives were not used if such species were in areas where there was a pot ential for them to be adversely impacted by the explosives.

103Analyses of Potential Effects of an Oil Spill on Fin, Humpback, and Bowhead Whales.

Following a large or very large oil spill, bal een whales could suffer adverse effects due to:

• inhalation of toxic components of crude oil;

• ingesting oil and/or contaminated prey;

• fouling of their baleen;

• oiling of skin;

• reduced food source; and

• displacement from feeding areas.

Effects of Inhalation of Toxic Components of Crude Oil The greatest threat to large cetaceans probably is from inhalation of volatile compounds present

in fresh crude oil. Based on literature on othe r mammals indicating seve re adverse effects of inhalation of the toxic aromatic components of fres h oil, mortality of whales could occur if they surfaced in large quantities of fresh oil. Inha lation of volatile hydrocar bon fractions of fresh crude oil can damage the respiratory syst em (Hansen 1985; Neff 1990) , cause neurological disorders or liver damage (Geraci and St. Aubi n 1982), have anesthetic effects (Neff 1990) and, if accompanied by excessive adrenalin rele ase, cause sudden death (Geraci 1988).

Based on evidence of observation of individuals fr om the AB pod of killer whales in heavy oil, and large disappearances of whales from the AB pod in the 2 years following that exposure (Dahlheim and Matkin 1994; Harvey and Dahlhe im 1994), one could conclude that whales are vulnerable, probably due to inhalation, if they ar e present within a large spill. However, this link is circumstantial, and there is not agreement in the scientific community as to whether or not there likely was an oil-spill impact on killer whales after the EVOS. Similarly, gray whales with apparently abnormal behavi or were observed in oil after th e EVOS in an area where fumes from the spill were apparently very strong (J. Lentfer, cited in Harvey and Dahlheim 1994). Subsequently large numbers of gray whale carca sses were discovered. One of three of these

whales had elevated levels of polycyclic aromatic hydrocarbons in its blubber. Loughlin (1994)

concluded it was unclear what caused the death of the gray whales. During the oil spill off Santa Barbara in 1969, an estimated 80,000 bbl of oil may have entered the marine environment. Gray whales were beginning their annu al migration north during the spill. Whales were observed migrating northward through the slick. Severa l dead whales were observed and carcasses recovered, including six gray whales, one sperm whale, one pilot whale, five common dolphins, one Pacific white-sided dolphin, and two unidentified dolphins. Brownell (1971, as reported by Geraci 1990) acknowledged that these whales to taled more than the usual number of gray whales and dolphins stranding a nnually on California shores, and concluded that increased survey efforts had led to the higher counts. Se veral of the whales exam ined were thought to have died from natural causes, and one may have been harpooned. No evidence of oil contamination was found on any of the whales examined. The Batelle Memorial Institute

concluded the whales were either able to avoid th e oil, or were unaffected when in contact with

it.

Based on all available informati on, if individual, small groups or , less likely, large groups of whales were exposed to large amounts of fresh oi l, especially through inha lation of highly toxic

104aromatic fractions, they might be seriously injure d or die from such exposure. Although there is very little definitive evidence linking cetacean death or seri ous injury to oil exposure, disappearances (and probable deaths) of killer whales and the deaths of large number of gray

whales both coincided with the EVOS and with obs ervations of members of both species in oil. However, in these two cases, even if one assume d the disappearances of the killer whales and the high number of gray whale carcasses both were the result of the coinciding oil spill, and one assumed impacts on bowhead whales of the same magnitude, it is unlikely that there would be a significant population-level a dverse effect in the even t of a large oil spill.

As noted above, we know of no fin, humpback, or bowhead whale deaths resulting from an oil spill. For the reasons discussed in the previous paragraph, it is difficult to predict the impact of a large or very large spill on these whales. Based on literature on ot her mammals indicating

severe adverse effects of inhalation of the toxic aromatic components of fresh oil, mortality of cetaceans could occur if they surface d in large quantities of fresh oil. We believe this is most likely if bowhead calves were exposed to fumes from a large spill. Calves take more breaths than do their mothers and spend more time at the surface. Thus, it is likely they would be most likely to succumb to inhalation of toxic aromatic compounds.

The potential for there to be long-term sublet hal (for example, reduced body condition, poorer health, reduced immune function, reduced repro duction or longer dependency periods) effects on large cetaceans from a large oil spill is essentially unknown. There are no data on large cetaceans adequate to evaluate the pr obability of sublethal effects.

Geraci and St. Aubin (1982) calcu lated the concentrations of hydr ocarbons associated with a theoretical spill of a typical light crude oil. They calculated the concentrations of the more

volatile fractions of crud e oil in air. The results showed th at vapor concentrations could reach critical levels for the first few hours after a spill. If a whale or dolphin were unable to leave the immediate area of a spill during that time, it woul d inhale some vapors, perhaps enough to cause damage. Fraker (1984) stated that a whale surf acing in an oil spill will inhale vapors of the lighter petroleum fractions, and many of these ca n be harmful in high concentrations. Animals that are away from the immediate area or that are exposed to weathe red oils would not be expected to suffer serious consequences from in halation, regardless of their condition. The most

serious situation would occu r if oil spilled into a lead that whal es could not escape. In this case, Bratton et al. (1993) theorized the whales could inhale oil vapor th at would irritate their mucous membranes or respiratory tract. They also could absorb volatile hydrocarbons into the

bloodstream. Within hours after th e spill, toxic vapors from oil in a lead could harm the whales’ lungs and even kill them. The number of whal es affected would depend on how large the spill was, its behavior after being spilled, and how many whales were present in areas contacted in the first several days following the spill.

Effects of Direct Contact of Skin and other Surfaces with Spilled Oil

Oil first would contact a whale’s skin as it surfaces to breathe. The effect s of oil contacting skin are largely speculative. We do not know how long sp illed oil will adhere to the skin of a freeranging whale. Oil might wash off the skin a nd body surface shortly after the whales vacated oiled areas, if they left shortly after being oiled. However, oil mi ght adhere to the skin and other surface features (such as callo sities on humpbacks or sensory hairs on bowheads) longer, if

whales remained in these areas or after leaving the oiled area.

105Bowhead whale eyes may be vulnerable to dama ge from oil on the water due to their unusual

anatomical structure. It is doc umented that crude oil can damage eyes (Davis, Schafer, and Bell 1960). Corneal ulcers and abrasi ons, conjunctivitis, and swol len nictitating membranes were observed in captive ringed seals placed in crude oil-covered wa ter (Geraci and Smith 1976), and in seals in the Antarctic after an oil spill (Lil lie, 1954). Corneal ulcers and scarring were observed in otters captured in oiled areas (M onnett and Rotterman 1989) and in oiled otters brought into oil-spill trea tment centers (Wilson et al. 1990) after the EVOS.

In a study on nonbaleen whales and other ceta ceans, Harvey and Dahl heim (1994) observed 80 Dall’s porpoises, 18 killer whales, and 2 harbor porpoises in oil on the wa ter’s surface from the EVOS. They observed groups of Dall’s porpoises on 21 occasions in areas with light sheen,

several occasions in areas with moderate-to-heavy surface oil, once in no oil, and once when they did not record the amount of oil. Thirteen of the animals were close enough to determine if oil was present on their skin. They confirmed that 12 animals in light sheen or moderate-toheavy oil did not have oil on th eir skin. One Dall’s porpoise ha d oil on the dorsal half of its body. It appeared stressed because of its labored breathing pattern. The authors gave no other

information on effects. The 18 killer whales an d 2 harbor porpoises were in oil but had none on

their skin. None of the cetacean s appeared to alter their behaviors when in areas where oil was present. The authors conclude d their observations were consis tent with other reports of cetaceans behaving normally when oi l is present. However, as noted above in the review of observations following other spills, observations of cetaceans behaving is a lethargic fashion or having labored breathing has been documented in more than one species, including one in which large numbers of individuals were subsequently found dead.

Histological data and ultrastr uctural studies by Geraci and St. Aubin (1990) showed that exposures of skin to crude oil for up to 45 minut es in four species of toothed whales had no effect. They switched to gasoline and applie d the sponge up to 75 minutes. This produced transient damage to epidermal cells in whales. Subtle changes were evident only at the cell level. In each case, the skin damage healed wi thin a week. They concluded that a cetacean’s

skin is an effective barrier to the noxious substances in petroleu m. These substances normally damage skin by getting between cells and disso lving protective lipids. In cetacean skin, however, tight intercellular bridges, vital surf ace cells, and the extraord inary thickness of the epidermis impeded the damage. The authors coul d not detect a change in lipid concentration

between and within cells after exposing skin from a white-sided dolphin to gasoline for 16 hours

in vitro.

Geraci and St. Aubin also investigated how oil might affect healing of superficial wounds in a bottlenose dolphin’s skin. They found that following a cut, newly exposed epidermal cells degenerate to form a zone of dead tissue that shields the underlying cells from seawater during healing. They massaged the superficial wounds w ith crude oil or tar for 30 minutes, but the

substances did not affect hea ling. Lead-free gasoline applied in the same manner caused strong inflammation, but it subsided with in 24 hours and was indistinguishab le from control cuts. The authors concluded that the dead tissue had prot ected underlying tissues from gasoline in the same way it repels osmotic attack by seawater. Th e authors further conclude d that in real life,

contact with oil would be le ss harmful to cetaceans than they and others had proposed.

While petroleum can damage mammalian skin, Geraci and St. Aubin (1985) reported little effects with exposures of 75 minutes. We noted that after a real spill, oil could be in contact with skin for much longer periods. Lipid composition was not modified, and epidermal cell

106proliferation was not significantly reduced. Ho wever, as pointed out by Harvey and Dahlheim (1994), the significance of these results is uncertain because of small sample sizes and the uncertainty of their applicability to natural situa tions. It is not clear w hy some cetaceans that are

observed in oil do not become oiled while at leas t a few apparently do. It is not clear how long crude oil would remain on a free-ranging cetacean’s skin once it was oiled. Bratton et al. (1993) synthesized studies on the poten tial effects of contaminants on bowhead whales. They concluded that no published data proved oil fouli ng of the skin of any free-living whales, and

conclude that bowhead whales contacting fresh or weathered pe troleum are unlikely to suffer

harm.

Although oil is unlikely to adhe re to smooth skin, it may stic k to rough areas on the surface (Henk and Mullan, 1997). Haldiman et al. (1985) found the epidermal layer to be as much as seven to eight times thicker than that found on mo st whales. They also found that little or no crude oil adhered to preserved bow head skin that was dipped into oil up to three times, as long as a water film stayed on the skin’s surface. Oil adhered in small patches to the surface and vibrissae (stiff, hairlike structures), once it ma de enough contact with the skin. The amount of oil sticking to the surrounding skin and epidermal depression appeared to be in proportion to the number of exposures and the roughness of the skin’s surface.

Albert (1981) suggested that oil would adhere to the skin’s rough surfaces (eroded areas on the skin’s surface, tactile hairs, a nd depressions around the tactile hairs). He theorized that oil could irritate the skin, especially th e eroded areas, and interfere with information the animal receives through the tactile hairs. Because we do not know how these hairs work, we cannot assess how any damage to them might affect bowheads. Al bert (1981) noted that er oded skin may provide a point of entry into the bloodstream for pathogenic bacteria, if the skin becomes more damaged. Evidence from Shotts et al. (1990) suggests that the lesions are active sites of necrosis. The authors noted that 38% of the microorganisms in lesions contained enzymes necessary for hemolytic activity of blood cells (breaking down of red blood cells and the release of hemoglobin) compared to 28% of the microorgani sms on normal skin. Many of these species of bacteria and yeast were determined to be potential pathogens of mammalian hosts.

The potential effect of crude oil on the function of the cetacean blowhole is unknown. As noted, a Dall’s porpoise was observed after the EVOS w ith crude oil covering it s skin and blowhole. This individual was described as having labor ed breathing. Other porpoise swimming in the same area in oil did not appear to be oiled or to have abnormal behavior (Harvey and Dahlheim, 1994).

Effects of Ingestion of Spilled Oil

It is documented that, with re spect to mammals in general, ingestion of petroleum hydrocarbons can lead to subtle and progressive organ damage or to rapid death. Also as noted above, many polycyclic aromatic hydrocarbons are teratogenic and embryotoxic in at least some mammals (Khan et al., 1987). Maternal exposure to crude oil during pregnancy may negatively impact birth weight and health of young in at least some mammals (Khan et al., 1987; Currie et al., 1970). In at least some marine mammals, digest ion and behavior is aff ected with decrease food assimilation of prey eaten (for example, St. Aubin, 1988), increased gastrointestinal motility, increased vocalization, and d ecreased sleep (Geraci and Smith, 1976; Engelhardt, 1985, 1987)

107(see discussion above for more detail). Oil i ngestion can decrease food assimilation of prey eaten (for example, St. Aubin, 1988).

Bowheads sometimes skim the water surface while feeding, filtering a lot of water for extended periods. If oil were present, they could swallow it. Albert (1981) suggested that whales could take in tarballs or large “blobs” of oil with prey. He also said that swallowed baleen “hairs” mix with the oil and mat together into small balls . These balls could block the stomach at the connecting channel, which is a very narrow t ube connecting the stomach ’s fundic and pyloric chambers (the second and fourth chambers of the stomach) (Tarpley et al., 1987). Humback and fin whales might also encounter oil as they feed by filtering large quantities of water. Hansen (1985; 1992) suggests that cetaceans can metabolize ingested o il, because they have cytochrome p-450 in their livers (Han sen, 1992). The presence of cytochro me p-450 (a protein involved in the enzyme system associated with the metabo lism and detoxification of a wide variety of foreign compounds, including components of crude oi l) suggests that cetaceans should be able to detoxify oil (Geraci and St. Aubin, 1982, as ci ted in Hansen, 1992). He also suggests that digestion may break down any oil that adhe res to baleen filaments and causes clumping (Hansen, 1985). Observations a nd stranding records do not reveal whether cetaceans would feed around a fresh oil spill long enough to accumulate a critical dose of oil. There is great uncertainty about the potential effects of inge stion of spilled oil on bow heads, especially on

bowhead calves. Decreased food assimilation coul d be particularly important in very young animals, those that seasonally feed, and those th at need to put on high levels of fat to survive

their environment.

Fin, humpback, and bowheads may swallow some oi l-contaminated prey, but it likely would be only a small part of their food. It is not known if whales would leave a feeding area where prey was abundant following a spill. Some zooplankton eaten by bowheads consume oil particles and bioaccumulation can result (see section on Pote ntial Effects on Food Source below). Tissue studies by Geraci and St. Aubin (1990) revealed low levels of naphthalene in the livers and blubber of baleen whales. This result suggests that prey have low concentr ations in their tissues, or that baleen whales may be able to meta bolize and excrete certain petroleum hydrocarbons.

Potential Effects of Baleen Fouling

If a baleen whale encountered spilled oil, baleen hairs might be fouled, which would reduce a whale’s filtration efficiency duri ng feeding. In a recent peer-rev iewed paper in the Journal of Mammalogy, Lambertsen et al. (2005:349) concluded that becau se previous “(E)xperimental

assessment of the effects of baleen function...thus far has considered exclusively the role of hydraulic pressure in powering bale en function...” but “...our presen t results indicate that more subtle hydrodynamic pressure may play a critical role in the function of the baleen in the...balaenids...the current state of knowledge of how oil would affect the function of the mouth of right whales and bowheads can be considered poor, despite considerable past research on the

effects of oil on cetaceans .”

Lambertsen et al. (2005) contende d that oil could be efficientl y ingested if globules of oil behave like prey inside the mouth. They point ou t that if oil is of lo w viscosity and does not behave like prey, only small amounts would be ingested. Lambertsen et al. (2005:350)

characterize these two conditions as being of “questionable validity” and note that if, on the other hand, the resistance of the baleen is significantly increase d by oil fouling, as experimental

108evidence on the baleen of other mysticetes indi cates it may be, the most likely adverse effect “...would be a substantial reduction in capture of larger, more activ ely mobile species, that is euphausiids, with possible reductions in capture of copepods and other prey ” (Lambertsen et al., 2005:350). They concluded that their results highlight the uncer tainty about how rapidly oil would depurate at the near zero temperatures of arctic waters and whethe r baleen function would be restored after oiling.

Earlier studies on baleen fouling were summari zed by Geraci (1990) who, with colleagues, had

also undertaken studies of the effects of oil on baleen function. Ger aci (1990:184) noted that while there was “A great deal of interest...in th e possibility that residues of oil may adhere to baleen plates so as to block the flow of wate r and interfere with feed ing. The concerns are largely speculative .” He also noted that “Such an effect may be imperceptible, though leading to subtle, long-term consequen ces to the affected animal .” Geraci (1990:184) concluded that “A safe assumption is that any substance in seawater which alters the characteristics of the plates, the integrity of the hairs, or th e porosity of the sieve may jeopard ize the nutritional well-being of

the animal.”

Braithwaite (1983, as cited in Br atton et al., 1993) used a simp le system to show a 5-10% decrease in filtration efficiency of bowhead bale en after fouling, which lasted for up to 30 days. Geraci (1990:186) stated th at the “Details of the experimental protocol” used in that study “...are not entirely clear.”

Geraci (1990) summarized studi es by Geraci and St. Aubin (1982, 1985) where the effects of contamination by different kinds of oil on humpback, sei, fin, and gray whale baleen were tested in saltwater ranging from 0 to 20 o C. In these studies, resistan ce to flow of some humpback baleen was increased more than 100%, less than 75% in gray and sei whale baleen, and gray whale samples were “relatively unaffected” (G eraci, 1990). Resistance to water flow through baleen was increased the greatest with contamination by Bunker C oil at the coldest temperatures. He summarized that oil of medium weight had little effect on resistance to water flow at any temperature. Fraker (1984) noted that there was a re duction in filtering efficiency in all cases, but only when the baleen was fouled with 10 millimeters of oil was the change statistically different.

In the study in which baleen from fin, sei, humpb ack, and gray whales was oiled, Geraci and St. Aubin (1985) found that 70% of th e oil adhering to baleen plates was lost within 30 minutes (Geraci, 1990) and in 8 of 11 trials, more than 95% of the oil was clea red after 24 hours. The study could not detect any change in resistance to water flowi ng through baleen after 24 hours.

The baleen from these whales is shorter and co arser than that of bowhead whales, whose longer baleen has many hairlike filaments. Geraci (1990) concluded that:

Combined evidence...suggests that a spill of he avy oil, or residual patches of weathered oil, could interfere with the feeding efficiency of the fouled plates for several days at least. Effects would likely be cumulative in an animal feeding in a region so blanketed by weathered oil that the rate of cleansi ng is outpaced by fouling. That condition could describe the heart of a spill, or a contaminated bay or lead

. Lighter oil should result in less interference with feeding effi ciency. Lambertsen et al. (2005)

concluded that results of their st udies indicate that Ge raci’s analysis of ph ysiologic effects of oiling on mysticete baleen “considered baleen function to be powered solely by hydraulic

109pressure,” a perspective they characterized as a “gross oversimplification of the relevant physiology.”

A reduction in food caught in the baleen could have an adverse affect on the body condition and

health of affected whales. If such an effect lasted for 30 days, as suggested by the experiments of Braithwaite (1983), this could po tentially be an effect that la sted a substantial proportion of the period that fin, humpback, and bowheads spen d on their summer feeding grounds. Repeated baleen fouling over a long time, however, might also reduce food intake and blubber deposition, which could harm the bowheads. As pointed ou t by Geraci (1990), the gr eatest potential for

adverse effects to bowheads w ould be if a spill occurred in the spring lead system.

Potential Effects on Food Source

Data from a recent study (Duesterloh, Short, and Barron, 2002) indicated that aqueous polyaromatic compounds (PAC) dissolved from w eathered Alaska North Slope crude oil are phototoxic to subarctic marine copepods at PAC c oncentrations that would likely result from an oil spill and at UV levels that are encountered in nature. Calanus marshallae exposed to UV in natural sunlight and low doses (~2μg of tota l PAC per liter (PAC/L) of the water soluble

fraction of weathered North Sl ope crude oil for 24 hours) showed an 80-100% morbidity and mortality as compared to less than 10% with exposure to the oil-on ly or sun-light only treatments. At 100% mortality occurred in Metridia okhotensis with the oil and UV treatment, while only 5% mortality occurred with the oil treatment alone. Duesterloh, Short, and Barron (2002) reported that phototoxic conc entrations to some copepod sp ecies were lower by a factor of 23 to >4,000 than the lethal concentrati ons of total PAC alone (0.05-9.4 mg/L).

This research also indicated that copepods may passively accumulate PACs from water and could thereby serve as a conduit for the transfer of PAC to higher trophic level consumers. Bioaccumulation factors were ~2,000 for M. okhotensis and about ~8,000 for C. marshallae

. Calanus and Neocalanus copepods have relatively higher bioaccumulation than many other species of copepods because of their characte ristically high lipid c ontent. The authors concluded that phototoxic effect s on copepods could conceivabl y cause ecosystem disruptions that have not been accounted for in traditional oil spill damage assessments. Particularly in

nearshore habitats where vertical migration of copepods is inhib ited due to shallow depths and geographical enclosure, phototoxi city could cause mass mortality in the local plankton population. (Duesterloh, S hort, and Barron, 2002:3959).

An oil spill probably would not permanently affect zoopla nkton populations, the bowhead’s major food source, and major effects are most li kely to occur nearshore (Richardson et al., 1987, as cited in Bratton et al., 1993). The amount of zooplankton lost, even in a large oil spill, would be very small compared to what is availabl e on the whales’ summer-feeding grounds (Bratton et al., 1993).

The potential effects to bowheads of expos ure to PACs through their food are unknown. Because of their extreme longevity, bowheads are vulnerable to incremental long-term accumulation of pollutants. With increasing de velopment within their range and long-distance transport of other pollutants, individual bowheads may experience multiple large and small polluting events within their lifetime.

110Fin and humpback whales feed primarily on small fish such as herring, capelin, and sandlance. These fish occupy the water column and do not have contact with the surface In the event of a large crude or diesel-fuel spill, effects on arctic fishes primar ily would depend on the season and location of the spill; the lifestage of the fishes (adult, juvenile, larval, or egg); and the duration

of the oil contact. Because of their low numbers in the spill area, no imme diate effects are likely on fishes during winter. Effect s more likely would occur from an offshore oil spill during summer or spring melt out, moving into nearshore waters, where fishes concentrate to feed, migrate, and spawn or rear. If an offshore spi ll did occur and contact the nearshore area, some marine and migratory fish likely would be harmed or killed. MMS has stat ed that for some of the more abundant fish species (e.g., capelin, he rring), spawning aggregations in some coastal reaches could be lost but could be replaced with in less than three generations from the larger population (MMS 2008). Thus, there is potential for local depletion of prey resources for fin and humpback whales.

Effects of Displacement from Feeding Areas

We have no observations of the response of bowhead whales following a large oil spill to determine whether they may be temporarily disp laced from an area because of an oil spill or cleanup operations. However, Thomas Brower, Sr. (1980) described the effects on bowhead whales of a 25,000-gallon (595-bbl) oil spill at Elson Lagoon (Plover Isla nds) in 1944. It took approximately 4 years for the oil to disappear. For four years after the oil spill, Brower observed

that bowhead whales made a wide detour outto sea when passing near Elson Lagoon/Plover Islands during fall migration. Bowhead whales nor mally moved close to these islands during the fall migration. These observations indicate that so me displacement of whales may occur in the event of a large oil spill, and th at the displacement may last for several years. Based on these observations, it also appears that bowhead whales may have some ability to detect an oil spill and avoid surfacing in the oil by detouring around the area of the spill.

Several other investigators have observed various cetaceans in sp illed oil, including fin whales, humpback whales, gray whales, dolphins, and pilo t whales. Typically, th e whales did not avoid slicks but swam through them, apparently showi ng no reaction to the oil. During the spill of

Bunker C and No. 2 fuel oil from the Regal Sword , researchers saw humpback and fin whales, and a whale tentatively identified as a right whale, surfacing and ev en feeding in or near an oil slick off Cape Cod, Massachusetts (Geraci and St. Aubin, 1990). Whales and a large number of white-sided dolphins swam, played, and fed in and near the slicks. The study reported no

difference in behavior between cetaceans within the slick and t hose beyond it. None of the observations prove whether cetaceans can detect oil and avoid it. None of these observations is sufficient to determine the long-term impacts of such exposure. Some researchers have concluded that baleen whales have such good su rface vision that they re ly on visual clues for

orientation in various activities. In particular, bowhead whales have been seen “playing” with floating logs and sheens of fluorescent dye on th e sea surface of the sea (Wursig et al., 1985, as cited in Bratton et al., 1993). These observations suggest that if oil is present on the sea surface and is of such quality or in such quantity th at it is readily optica lly recognizable, bowhead whales may be able to recognize and avoid it (Bratton et al., 1993) . However, the observation of their playing with dye may also indica te that they woul d play with it.

111After the EVOS, researchers studied the potential e ffects of an oil spill on cetaceans. Dahlheim and Loughlin (1990) documented no effects on the humpback whale. Von Ziegesar, Miller, and Dahlheim (1994) found no indication of a cha nge in abundance, calving rates, seasonal residency time of female-calf pairs, or mortality in humpback whales as a result of that spill, although they did see temporary displacement from some areas of Prince William Sound. It was difficult to determine whether the spill change d the number of humpback whales occurring in Prince William Sound. This study could not have detected long-term physiological effects to whales or to the humpback’s prey.

Cleanup operations following a large or very large spill would be expected to involve multiple marine vessels operating in the spill area for extended periods of time, perhaps over multiple years. Based on information provided in the ab ove section on vessel tra ffic, bowheads react to the approach of vessels at greate r distances than they react to mo st other industrial activities. According to Richardson and Malme (1993), most bowheads begin to swim rapidly away when vessels approach rapidly and di rectly. Avoidance usually begi ns when a rapidly approaching vessel is 1-4 km (0.62-2.5 mi) away. A few whales ma y react at distances from 5-7 km (3-4 mi).

After a large or very large spill, there are typically overflights usi ng helicopters and fixedwinged aircraft to track the spill and to determin e distributions of wildlife that may be at risk from the spill. We summarize the response of bowheads to airc raft here. Most bowheads are unlikely to react significantly to occasional singl e passes by helicopters flying at altitudes above 150 m (500 ft). At altitudes be low 150 m (500 ft), some bowhead s probably would dive quickly in response to the aircraft noise (Richardson and Malme, 1993; Patenaude et al., 1997) and may have shortened surface time (Patenaude et al., 19 97). Bowhead reactions to a single helicopter flying overhead probably are temporary (Richardson et al., 1995a). Whales should resume their

normal activities within minutes. Fixed-wing aircraft flying at low altitude often cause hasty dives. Reactions to circling aircraft are some times conspicuous if the aircraft is below 300 m (1,000 ft), uncommon at 460 m (1,500 ft), and ge nerally undetectable at 600 m (2,000 ft). Repeated low-altitude overflights at 150 m (500 ft) sometimes caused abrupt turns and hasty dives (Richardson and Malme, 1993). The effects fr om an encounter with aircraft are brief, and

the whales should resume their normal activities within minutes.

Based on all of the above information, we conclude that there could potentially be displacement of fin, humpback, and bowhead whales from a f eeding area following a large or very large spill and this displacement could last as long as ther e is a large amount of oil and related clean-up vessels present.

Conclusions of Potential Oil-Spill Effects

The effects of a large oil spill and subsequent exposure of fin, humpback, or bowhead whale populations to fresh crude oil ar e uncertain, speculative, and cont roversial. The effects would depend on how many whales contacted oil; the ag es and reproductive condition of the whales contacted; the duration of contact , the amount of oil spilled, and the age/degree of weathering of the spilled oil at the time of c ontact. The number of whales c ontacting spilled oil would depend on the size, timing, and duration of the spill; how many whales were near the spill; and the whales’ ability or inclination to avoid contact. If oil got into leads or ice-free areas frequented by migrating bowheads, a large por tion of the population could be e xposed to spilled oil. If a very large slick of fresh oil contacted a large aggregation or aggregati ons of feeding whales,

112especially with a high percent of calves, the effect might be ex pected to be greater than under more typical circumstances. Th ere is great uncertainty about th e effects of fresh crude oil on cetacean calves. Prolonged exposur e to freshly spilled oil could kill some adult whales, but, based on available information, the number likely w ould be small if the spill contacted whales in open water. However, Engelhardt (1987) theorized that bowhead whales would be particularly vulnerable to effects from oil sp ills during their spring migration into arctic wate rs because of their use of ice edges and leads, where spilled oi l tends to accumulate. Several other researchers (Geraci and St. Aubin, 1982; St. Aubin, Stinson, and Geraci, 1984) concl uded that exposure to spilled oil is unlikely to have serious direct eff ects on baleen whales. There is some uncertainty and disagreement within the scie ntific community on the results of studies on the impacts of the EVOS on large cetaceans (for example, Lough lin, 1994, Dahlheim and Matkin, 1994, Dahlheim and Loughlin, 1990). Bowheads, fins and humpbacks may also have heightened vulnerability to spilled oil because of the functiona l morphology of their baleen. If baleen in fouled, and if crude oil s ingested, there could be a dverse effects on the feeding effi ciency and food assimilation of these whales. Such effects are expected to be of most importance to calves, pregnant females, and lactating females. However, loss of feedi ng efficiency could potentially reduce the chance of survival of any whale and could affect the amount of energy female whal es have to invest in reproduction.

Assuming that development and production occurs, la rge oil spills are less likely to occur in the

Beaufort Sea than in the Chukchi Sea. MMS estimates about a 40% ch ance of a spill of 1,000 bbl in the Chukchi Sea Planning Area should production occur.

Despite the fact that there is no definitive mortality of a large cetacean due to an oil spill, based on the fact that certain components of crude oil are highly toxic to other mammals, such mortality could potentially occur. Ingestion, su rface contact with, and es pecially inhalation of

fresh crude oil has been shown to cause serious damage and even death in many species of

mammals. This does not mean that such effect w ould occur. Such an as sumption, if it provides an overestimate of potential effects, is more pr otective of the population than erring on the side of assuming that such impacts could not occu r because they previously have not been documented. Relatedly, because of unique ecologi cal characteristics of the bowhead whale in particular, they may be more vulnerable than ot her cetaceans to large and very large oil spills within their range (see below).

In conclusion, we reiterate that there is uncer tainty about effects on fin, humpback, or bowheads in the unlikely event of a very large spill. Th ere are, in some years and in some locations, relatively large aggregations of feeding bowhead whales within the Beaufort Sea. If a large amount of fresh oil contacted a significant portio n of such an aggregation, effects potentially could be greater than typically would be assume d. Additionally, highly si gnificant effects could occur if a large number of females and newborn or very young calves were contacted by a large

amount of fresh crude oil. Available informati on indicates it is unlikely that fin, humpback, or bowhead whales would be likely to suffer signi ficant population-level adverse affects from a large spill originating in the C hukchi or Beaufort Sea. Howeve r, individuals or small groups could be injured or potentially even killed in a large sp ill. Oil spill response activities (including active attempts to move whales away from oile d areas) could cause short-term changes in local

distribution and abundance.

CONCLUSION

113The effects of noise on fin, humpback, and bow heads from various OCS production activities

have been described. The effects from an encount er with aircraft genera lly are brief, and the

whales should resume their normal activities wi thin minutes. Whales may exhibit temporary

avoidance behavior to vessels at a distance of 1-4 kilometers. Ma ny earlier studies indicate that

most bowheads exhibit avoidance behavior when exposed to sounds from seismic activity.

Bowheads also exhibited tendencies for reduced surfacing and dive duration, fewer blows per surfacing, and longer intervals between successive blows. Bowheads appeared to recover from these behavioral changes within 30-60 minut es following the end of seismic activity. Monitoring has shown bowheads avoid areas ex posed to seismic sounds, with near total

avoidance of the area within 20 km or 11 n. mi . (12 st. mi.) of the source vessel at times influenced by airgun operations. Data from monitoring seismic operations from 1996-98 suggested that the offshore displacement may have begun roughly 35 km (19 n. mi. or 22 st. mi.) east of the activity, and may have persiste d >30km to the west (Richardson, 1999a).

Bowheads have been sighted within 0.2-5 k ilometers from drill ships, although bowheads change their migration speed and swimming di rection to avoid close approach to noiseproducing activities. Bowheads may avoid drilli ng noise at 20-30 kilometers. There are no observations of fin, humpback, or bowhead reactions to icebreakers breaking ice, but it has been predicted that roughly half of exposed bowheads would respond at a distance of 4.6-20 kilometers when the S:N is 30 dB. Overall, we believe fin, humpbac k, or bowhead whales exposed to noise-producing activities most likely would experience temporary, nonlethal effects.

Some avoidance behavior coul d persist up to 12-24 hours.

MMS investigated the probabil ity of spilled oil contacting bowhead whales (MMS 2000). Specific offshore areas (Ice/Sea Segments or ISS) were identified and modeled for probability of contact. Certain of these ISS’s overlay the migrat ory corridor of the bowhe ad. Using data from the MMS oil spill analysis for Sale 170, and a ssuming an oil spill of 1,000 barrels or more occurred at any of several offshore release areas (launch boxes) during the summer season, the chance of that oil contacting these ISS’s within 30 days during the summer season ranged from

5-82%. The reader should note that the MMS model includes ISS’ s that are within the launch box. That is, some of the offshore habitats bein g assessed for probability of contact lay within the area of the theoretical spill release. Despite the statistical probabilities presented, which depend on a spill contacting a discrete area, NMFS believes there are many scenarios for which the conditional probability of spill ed oil reaching areas utilized by bowhead whales is 100%.

Most whales exposed to spilled oil are expected to experience temporary, nonlethal effects from skin contact with oil, inhalation of hydrocarbon vapors, ingestion of oil-contaminated prey items, baleen fouling, reduction in food resource s, or temporary displacement from some feeding areas. A few individuals may be killed as a result of e xposure to freshly spilled oil. However, the combined probabilities of a spill occurring and also contacting bowhead habitat during periods when whales are present is consider ed as low, and the perc entage of the Beaufort Sea stock so-affected is expected to be very small.

The probability of an oil spill increases as more oil fields become active. Few empirical data

exist on the effects of oil and these whales. No measurable impact on humpback whales in

Prince William Sound was observed in 1989 as a result of the Exxon Valdez oil spill (von

114Ziegesar et al., 1994:188), but a co incident decline in numbers of killer whales following this spill suggests that whales may be severely impacted by an oil spill (Matkin et al. 1994). Without conclusive data, it is assumed that bowhead, fi n and humpback whales would be susceptible to an oil spill during feeding and migr ation, particularly if they came in contact with oil in the lead system during spring migration. A number of sm all oil spills have occurred during oil and gas exploration in the Alaskan Beaufort Sea in past ye ars. Only five spills have been greater than one barrel, and the total spill volume from drilling 52 exploration wells (1982 through 1991) was 45 barrels (USDOI, MMS, 1996). Based on hist orical data, most oil spills would be less than one barrel, but a larger oil spill could also occur. Consider ing the number of days each year that fin, humpback, or bowhead whales may be present in or migrating through the Chukchi or Beaufort Seas, the probability th at a spill would occur, the probabi lity for a spill to occur or persist during periods when whales are present, and the probability that oil would move into the migration corridor of the whales or waters in which whales occu r, it is unlikely that fin, humpback, or bowhead whales would be impact ed by oil. Significant adverse affects would only be expected if all of the low probabil ity events occurred at the same time.

Taking these factors into consideration, NMFS concl udes that, at this time, there is a reasonable likelihood that oil and gas development and produ ction in the Alaskan Beaufort and Chukchi Seas, as described, would not violate section 7(a)(2) of the ESA.

After reviewing the current status of the endangered bowhead whale , the environmental baseline for the action area, the proposed action, and the cumulative effects, it is NMFS’ biological opinion that individual bowhead whales within the action area ma y be adversely affected, but

that the proposed action is not likely to jeopardize the continued existence of Western Arctic

bowhead whales . No critical habitat has been designated for this species, therefore, none will be

affected.

After reviewing the current status of the endangered fin whale , the environmental baseline for the action area, the proposed act ion, and the cumulative effects, it is NMFS’ biological opinion

that individual fin whales within the action area may be adversely affected, but that the proposed action is not likely to jeopar dize the continued existence of North Pacific fin whales . No critical habitat has been designated for this sp ecies, therefore, none will be affected.

After reviewing the current status of the endangered humpback whale , the environmental baseline for the action area, the proposed act ion, and the cumulative effects, it is NMFS’ biological opinion that individua l humpback whales within th e action area may be adversely affected, but that the proposed action is not likely to jeopardize the continued existence of humpback whales . No critical habitat has been designated for this species; therefore, none will

be affected.

VIII. CONSERVATION RECOMMENDATIONS

Section 7(a)(1) of the ESA directs Federal agenci es to utilize their authorities to further the purposes of the Act by carrying out conservati on programs for the bene fit of endangered and

115threatened species. Conservation recommendati ons are discretionary agency activities to minimize or avoid adverse effects of a proposed ac tion on listed species or critical habitat, to help implement recovery plans, or to develop information.

The National Marine Fisheries Service and the Mi nerals Management Service should implement the following measures for these purposes:

1. MMS and NMFS should continue research to update environmental inventories for the Chukchi Sea. Marine mammal surveys shoul d be continued. MMS should consider a comprehensive program for this purpose which employs aerial and ship-based efforts as well as the use of passive acoustics. In particular, the current BWASP program should be expanded to include Block 13. MMS should particularly engage in research to describe bowhead whale behavior, movements and distribution, and important habitats in these waters. Efforts should be made to acquire photographs of humpbackwhales within the action area for photoidentification. NMFS and MMS shall encourage industry to photographs humpback whales they

encounter.

2. Vessel operations in the Beaufort Sea, incl uding seismic geophysical exploration, should be scheduled to minimize operations in order to reduce potential hara ssment of whales. These activities should, to the extent practicable, avoi d bowhead migratory periods in the spring and fall. Vessel operators should ma intain separation with the bowh ead whale migrational corridor by remaining 35 miles offshore whenever possible.

3. The MMS should continue research to descri be the impact of exploration activities on the migrational movements and feeding behavior of the bowhead whale. Specific plans should be developed and implemented to monitor the cumula tive effects of exploration, development, and production on the bowhead whale. These research designs and results should be reviewed annually to ensure that the information collected is addressing the concerns of NMFS and the

affected Native communities.

4. The MMS should continue to provide Informati on to Lessees and Lease Stipulations intended to reduce impacts to the bowhead whale, including stipulations on protection of biological resources, industry site-specific bowhead wh ale monitoring program, and conflict avoidance mechanisms to protect subsistence whaling an d other subsistence activ ities. It may be appropriate to develop similar langua ge to address humpback whales.

5. To minimize potential harassment of fin, hu mpback, and bowhead whales, operators should be advised that aircraft (other than monitori ng flights) should observe a minimum altitude of 1500 feet (approximately 500 meters), w eather and safety factors permitting.

6. Major oil spills are not anticipated during ex ploration activities. Howe ver, to avoid adverse effects should a major oil spill occur, NMFS a nd MMS should cooperate with the USCG to ensure that areas occupied by bowhead, fin or humpback whales are clear of spilled oil. Special precautions should be taken to ensure that spilled o il does not reach or persist in areas in or near the spring lead system (SLS) used by bowhead whales during their spring migration (April

116through June), the fall migrational corridor, or whale feeding areas. The NMFS and MMS should investigate the possible use of airguns as a deterrent for whales near an oil spill.

Research has shown most whales avoid these noise sources by at least 20 km, and an airgun system may be an effective tool in any North Slope offshore res ponse arsenal for the intentional hazing of bowhead whales.

7. Upon learning of any unauthorized take of bowh ead, fin or humpback whales which occurs as a result of OCS exploratory activity, NMFS or MMS should immediately notify the assistant Regional Administrator for Protected Resources at (907) 586-7235 of this taking to determine the appropriate and necessary course of action.

8. MMS and NMFS should use their authorities to avoid multiple seismic work operating in such manner as to significantly impair the bowhead migration. Multiple seismic operations should be prohibited from operati ng offshore of one another (i.e., to the north or south) when they might cause a delay in the migratory movements of bowhead whales. This measure does not include high-resolution seismic operations, or seismic work nearshore or in shallow waters which have less potential to harass or harm bowhead whales.

9. The MMS and NMFS should continue to coordina te research associated with OCS actions and the fin, humpback, and bowhead whale, with emphasis on cumulative impacts of OCS activities. These agencies are encouraged to cooperatively appro ach this issue.

10. The MMS should continue to investigate the use of the C hukchi and Beaufort Seas by feeding bowhead whales, and assess the importance of this feeding to the health and well being

of these animals.

11. The NMFS and MMS should consider the traditi onal observations of Eskimo hunters of the importance of the nearshore waters of the Chukchi and Beaufort Seas in their decision making. The MMS should take measures to protect and c onserve these values, in cluding consideration of deferral areas, to protect im portant habitat areas.

12. The MMS should investigate methods to acquire necessary geophysical data using alternative methods for airguns, or to develop improved software or other technologies which would effectively reduce the level of noise from airguns used fo r geophysical research.

13. The MMS should defer from leasing those tracts within the SLS of the Chukchi and Beaufort Seas. Additionally, seismic geophysical surveys should not occur within these areas prior to open-water conditions, and MMS should consider means to minimize any activities which may cross or occupy the SLS, such as pipelines.

14. NMFS and MMS should advocate that all oil and ga s-related exploration activities which may result in the taking of endangered marine mammals be authorized under the Marine

Mammal Protection Act. NMFS shall condition th ese authorizations as necessary to minimize

adverse effects and ensure each action would have no more than a negligible level of impact to the stock(s) of endangered mari ne mammal. Mitigative measures shall be included which are intended to prevent mortality or serious injury.

117IX

. REINITIATION OF CONSULTATION

This concludes formal consultation on this ac tion. As provided in 50 CFR §402.16, reinitiation of formal consultation is requi red where discretionary Federal agency involvement or control

over the action has been retained (or is authorized by law) and if : (1) the amount or extent of incidental take is exceeded; (2) new informati on reveals effects of the agency action that may affect listed species or critical habitat in a ma nner or to an extent not considered in this Biological Opinion; (3) the agency action is subsequently modifi ed in a manner that causes an effect to the listed species or critical habitat not considered in this Biological Opinion; or (4) a new species is listed or critic al habitat designated that may be affected by this action. In

circumstances where the amount or extent of in cidental take is exceeded, any operations causing such take must cease pending reinitiation.

Also, leasing and exploration activities within the area of the Chukchi and Beaufort Sea which includes the spring lead/polynya system are not expected to occur during the spring bowhead whale migration (April through June). If new technology, procedures, etc. are developed which allow for these activities during this period, addi tional and separate consultation under section 7 (a)(2) of the ESA will be necessary.

X. INCIDENTAL TAKE STATEMENT Section 9 of the ESA and Federal regulations pur suant to section 4(d) of the ESA prohibit the take of endangered and threaten ed species, respectively, without special exemption. Take is defined as to harass, harm, pursue, hunt, shoot, w ound, kill, trap, capture or collect, or to attempt to engage in any such conduct. In cidental take is define d as take that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity. Under the te rms of section 7(b)(4) and section 7(o)(2), taking that is incidental to and not intended as part of the agency action is not considered to be prohibited taking under th e ESA provided that such taking is in compliance

with the terms and conditions of th is incidental take statement.

This opinion does not include an incidental take statement at th is time. Upon issuance of regulations or authorizations under Section 101(a)(5) of the Marine Mammal Protection Act and/or its 1994 Amendments, NMFS will amend this opinion to include an incidental take statement(s) for the described work.

XI. LITERATURE CITED

Aguilar A, Lockyer CH. 1987. Growth, physical maturity, and mortality of fin whales (Balaenoptera physalus ) inhabiting the temperate waters of the Northeast Atlantic. Can. J. Zool./J. Can. Zool. 65(2):253-264.

Allen, K.R. 1980. Conservation and management of whales. Univ. of Washington Press, Seattle.

Angliss, R.P. and A.L. Lodge. 2003. Final 2003 Al aska Marine Mammal Stock Assessment. Juneau, AK: USDOC, NOAA, NMFS.

Angliss, R.P. and A.L. Lodge. 2005. Alaska Marine Mammal Stock Assessment. Juneau, AK: USDOC, NOAA,

NMFS.

118Angliss, R.P. and R. Outlaw, eds. 2005. Draft Alaska Marine Mammal Stock Assessments 2005. Report SCCAMLR-XXIV. Juneau, AK: National Marine Mammal Lab., Alaska Fisheries Science Center.

Angliss, R. P. and R. Outlaw. 2006. Alaska Marine Mammal Stock Assessments, 2005. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-AFSC-168, 255 p.

Angliss, R.P., and R. B. Outlaw. 2008. Alaska marine mammal stock assessments, 2007. U. S. Dep. Commer., NOAA Tech. Memo., NMFS-AFSC-180, 252 p.

Baker CS, Herman LM. 1989. Behavioral responses of summering humpback whales to vessel traffic: Experimental and opportunistic observations. Kewalo Basin Mar. Mamm. Lab., Univ. Hawaii, Honolulu, HI, for U.S. Natl. Park Serv., Anchorage, AK. Report nr NPSNR-TRS-89-01 NTIS PB90-198409. 50 p.

Baretta L, Hunt GL. 1994. Changes in the number of cetace ans near the Pribilof Islands, Bering Sea, between 1975-

78 and 1987-89. Arctic 47:321-326.

Barlow J, Forney KA, Hill PS, Jr. RLB, Carretta JV, DeMaster DP, Julian F, Lowry MS, Ragen T, Reeves RR. 1997. U.S. Pacific Marine Mammal Stock Assessments: 1996 NOAATechnical Memorandum. Report nr NOAA-TM-NMFS-SWFSC-248. 224 p.

Bauer, G. B., J. R. Mobley, and L. M. Herman. 1993. Responses of wintering humpback whales to vessel traffic.

J. Acous. Soc. Amer. 94:1848.

Bauer GB. 1986. The behavior of humpback whales in Hawaii and modification of behavior induced by human interventions. Ph.D. dissertation, University of Hawaii, Honolulu.

Beach, D.W., and M.T. Weinrich. 1989. Watching the whales: Is an educati onal adventure for humans turning out to be another threat for enda ngered species? Oceanus 32(1):84 B 88.

Becker, P.R., E.A. Mackey, M.M. Schant z, R. Demiralp, R.R. Greenberg, B.J. Koster, S.A. Wise, and D.C.G. Muir. 1995. Concentrations of Chlorinated Hydrocarbons, Heavy Metals and Other Elements in Tissues Banked by the Alaska Marine Mammal Tissue Archival Project. OCS Study, MMS 95-0036. Silver Spring, MD: USDOC, NOAA, NMFS, and USDOC, National Institute of Standards and Technology.

Bengston, J. and M. Cameron. 2003. Marine Mammal Su rveys in the Chukchi and Beaufort Seas. In: AFSC Quarterly Research Reports July-Sept. 2003. Juneau, AK: USDOC, NOAA, NMFS, Alaska Fisheries Science Center, 2 pp.

Blackwell, S.B. and C.R. Greene, Jr. 2001. Sound Measurements, 2000 Break-up an d Open-water Seasons. In: Monitoring of Industrial Sounds, Seals, and Whale Calls During Construction of BP’s Northstar Oil Development, Alaskan Beaufort Sea, 2000. LGL Report TA 2429-2. King City, Ont., Canada: LGL Ecological Research Associates, Inc., 55 pp.

Blackwell, S.R. and C.R. Greene, Jr. 2004. Sounds from Northstar in the Open-Water Season: Characteristics and

Contribution of Vessels. In: Monitoring of Industrial Sounds, Seals, and Bowhead Whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 19 99-2003, W.J. Richardson and M.T. Williams, eds. LGL Report TA4002-4. Anchorage, AK: BPXA, Dept. of Health, Safety, & Environment.

Bluhm, Bodil A. and R. Gradinger, 2008. Regional variabi lity in food availability for arctic marine mammals. Ecol Appl., 18(2). 19p.

Bowles, A.E., M. Smultea, B. Wursig, D.P. DeMaster, and D. Palka. 1994. Relative Abundance and Behavior of Marine Mammals Exposed to Transmissions from the Heard Island Feasibility Test. J. Acoust. Soc.

America 96:2469-2484.

119BP Exploration (Alaska), Inc. 1998. Liberty Development Project, Environmental Report. Anchorage, AK:

BPXA.

Braithwaite, L.F. 1983. The Effects of Oil on the Feeding Mechanism of th e Bowhead Whale. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 45 pp.

Bratton, G.R., C.B. Spainhour, W. Flory, M. Reed, and K. Jayko. 1993. Presence and Potential Effects of

Contaminants. In: The Bowhead Whale , J.J. Burns, J.J. Montague and C.J. Cowles, eds. Special Publication 2 of The Society for Marine Mammal ogy. Lawrence, KS: The Society for Marine Mammalogy, 701-744.

Bratton, G.R., W. Flory, C.B. Spainhou r, and E.M. Haubold. 1997. Assessment of Selected Heavy Metals in Liver, Kidney, Muscle, Blubber, and Visceral Fa t of Eskimo Harvested Bowhead Whales Balaena mysticetus from Alaska’s North Coast. North Slope Borough Contracts #89-293; #90-294. College Station, TX: Texas A&M University, p. 233.

Brigham, L. and B. Ellis, eds. 2004. Arctic Mari ne Transport Workshop, Scott Polar Research Institute, Cambridge University, Sept. 29-30, 2004. Anchorage, AK: Circumpolar Infrastructure Task Force, Secretariat at the Institute of the North; United Stat es Arctic Research Commission; International Arctic

Science Commision.

Brownell, R. L., T. Kasuya, W. P. Perrin, C. S. Baker, F. Cipriano, J. Urban R., D. P. DeMaster, M. R. Brown, and P. J. Clapham. 2000. Unknown status of the west ern North Pacific humpback whale population: a new conservation concern. Unpublished report to the International Whaling Commission. 5p.

Buckland ST, Cattanach KL, Lens S. 1992. Fin whale abundance in the eastern North Atlantic, estimated from Spanish NAA-89 data. Report of the International Whaling Commission 42:457-460.

Calambokidis J, Steiger GH, Straley JM, Quinn T, Herman LM, Cerchio S, Salden DR, Yamaguchi M, Sato F, Urban JR and others. 1997. Abundance and population structure of humpback whales in the North Pacific basin. Final Contract Report 50ABNF500113 to Southwest Fisheries Science Center, P.O. Box 271, La Jolla, CA 92038. 72 pp.

Carretta, J.V., J. Barlow, K.A. Forney, M.M. Muto, and J. Baker. 2001. U.S. Pacific Marine Mammal Stock Assessments, 2001. NMFS-SWFSC-300. S eattle, WA: USDOC, NMFS, 276 pp.

Carroll, G.M., J.C. George, L.F. Lowry, and K.O. Coyle. 1987. Bowhead Whale ( Balaena mysticetus ) Feeding near Point Barrow, Alaska during the 1985 Spring Migration. Arctic 40:105-110.

Caulfield, R.A. 1993. Aboriginal subsistence whaling in Greenland: the case of Qeqertarsuaq municipality in West Greenland. Arctic 46:144 B 155.

Charif RA, Mellinger DK, Dunsmore KJ, Fristrup KM, Cl ark CW. 2002. Estimated source levels of fin whale ( Balaenoptera physalus ) vocalizations: adjustments for surface interference. Marine Mammal Science 18(1):81-98.

Clapham P, Mayo CA. 1987. Reproduction and recruitment of individually identified humpback whales, Megaptera novaeangliae, observed in Massachusetts Bay, 1979-1985. Canadian Journal of Zoology 65(12):2853-

2863.

Clapham P. 1996. The social and reproductive biology of humpback whales: an ecol ogicalperspective. Mammal

Review 26:27-49.

Clapham, P.J., S. Leatherwood, I. Szczepaniak, and R.L. Brownell, Jr. 1997. Catches of humpback and other whales from shore stations at Moss Landing and Trinidad, California, 1919B1926. Mar. Mamm. Sci. 13:368B394.

120Clapham, P.J. and R.L. Brownell, Jr. 1999. Vulnerability of Migratory Baleen Whales to Ecosystem Degradation. Convention on Migratory Species, Technical Publication No. 2. Lawrence, KS: Society for Marine Mammalogy, pp. 97-106.

Clark CW, Charif R. 1998. Monitoring the occurrence of large whales off North and West Scotland using passive acoustic arrays. Society of Petroleum Engineers (SPE). SPE/UKOOA European Environmental Conference, Aberdeen, Scotland. April 1997.

Clark, C.W., W.T. Ellison, and K. Beeman. 1986. A Preliminary Account of the Acoustic Study Conducted During the 1985 Spring Bowhead Whale, Balaena mysticetus , Migration Off Point Barrow, Alaska. Report of the International Whaling Commission No. 36. Cambridge, UK: IWC, pp. 311-317.

Clark CW. 1995. Application of U.S. Navy underwater hydrophone arrays for scientific research on whales. Report of the International Whaling Commission 45:210-212.75

Cooper, L.W., I.L. Larsen, T.M. O’Hara, s. Dolvin, V. Wo shner, and G.F. Cota. 2000. Radionuclide Contaminant

Burdens in Arctic Marine Mammals Harv ested During Subsistence Hunting. Arctic 532:174-182.

Corkeron, P. J . 1995. Humpback whales ( Megaptera novaeangliae ) in Hervey Bay, Queensland: Behaviour and responses to whale-watching vessels. Can. J. Zoo. 73:1290-1299.

Croll DA, Tershy BR, Acevedo A, Levin P. 1999. Marine vertebrates and low frequency sound. Technical Report for LFA EIS. Santa Cruz, CA: Marine Mammal and Seab ird Ecology Group, Institute of Marine Sciences, University of California.

Currie, A.R., C.C. Bird, A.M. Crawford, and P. Sims. 1970. Embryopathic Effects of 7,12- dimehylbenz(a)anthracene and its Hydroxymethyl Derivatives in the Sprague-Dawley Rat. Nature

226:911-914.

Dahlheim, M.E. and C.O. Matkin. 1994. Assessment of Injuries to Prince William Sound Killer Whales. In : Exxon Valdez Oil Spill Symposium Abstract Book, B. Spies, L.G. Evans, M. Leonar d, B. Wright, and C. Holba, eds. and comps. Anchorage, Ak., Feb. 2-5, 1993. Anchorage, AK: Exxon Valdez Oil Spill Trustee Council; University of Alaska Sea Grant College Pr ogram; and American Fisheries Society, Alaska Chapter, pp. 308-310.

Dahlheim, M.E. and T.R. Loughlin. 1990. Effects of the Exxon Valdez Oil Spill on the Distribution and Abundance of Humpback Whales in Prince W illiam Sound, Southeast Alaska, and the Kodiak Archipelago. In: Exxon Valdez Oil Spill Natural Resource Damage Assessment. Unpublished report. NRDA Marine Mammals Study No. 1. Seattle WA: USDOC, NOAA.

Davies, J.R. 1997. The Impact of an Offshore Drilling Pl atform on the Fall Migration Path of Bowhead Whales: A

GIS-Based Assessment. M.S. Thesis. S eattle, WA: Western Washington University.

Davis, A., L.J. Schafer, and Z.G. Bell. 1960. The Effects on Human Volunteers of Exposure to Air Containing Gasoline Vapors. Archives of Environmental Health 1:584-554.

Davis, R.A. 1987. Integration and Summary Report. In: Responses of Bowhead Whales to an Offshore Drilling Operation in the Alaskan Beaufort Sea, Autumn 1986. Anchorage, AK: Shell Western E&P, Inc., pp. 1-

51.

Davis, R.A., C.R. Greene, an d P.L. McLaren. 1985. Studies of the Po tential for Drilling Activities on Seal Island to Influence Fall Migration of Bowhead Whales Thr ough Alaskan Nearshore Waters. King City, Ont., Canada: LGL Limited Environmental Research Associates, 70 pp.

DeMAster, D., D. Rugh, A. Rooney, J. Brewick, K. Shelden, and S. Moore. 2000. Review of studies on stock

121identity of the bowhead whale from the western arctic . Paper SC/52/SD4 presented to the IWC Scientific Committee, June 2000 (unpublished). 27p.

Dolphin WF. 1987. Ventilation and dive patterns of humpback whales Megaptera novaeangliae , on their Alaskan feeding grounds. Canadian Journal of Zoology 65(1):83-90.

Duesterloh, S., J.W. Short, and M.G. Barron. 2002. Photoenhanced Toxicity of Weathered Alaska North Slope Crude Oil to the Calanoid Copepods Calanus marshallae and Metridia okhotensis. Environmental Science and Technology 36(8:)953-3959 .

Edds PL. 1988. Characteristics of finback Balaenoptera physalus vocalizations in the St. Lawrence Estuary.

Bioacoustics 1:131-149.

Edds, P.L., and J.A.F. Macfarlane. 1987. Occurrence and general behavior of balaen opterid cetaceans summering in the St. Lawrence Estuary, Canada. Can. J. Zool. 65:1363 B 1376.

Edds-Walton PL. 1997. Acoustic communication signals of mysticete whales. Bioacoustics 8:47-60.

Engelhardt, F.R. 1987. Assessment of the Vulnerability of Marine Mammals to Oil Pollution. In: Fate and Effects of Oil in Marine Ecosystems. Proceedings of the Conference on Oil Pollution Organized under the auspices of the International Association on Wate r Pollution Research and Control (IAWPRC) by the Netherlands Organization for Applied Scientific Res earch TNO Amsterdam, The Netherlands, J. Kuiper and W.J. Van Den Brink, eds. Boston: Martinus Nijhoff Publishers, pp. 101-115.

Erbe, D. and D.M. Farmer. 1998. Masked Hearing Thresholds of a Beluga Whale ( Delphinapterus leucas) in

Icebreaker Noise. Deep-Sea Research Part II - Tropical Studies in Oceanography 45:1373-1388.

Erbe, C., A.R. King, M. Yedlin, and D.M. Farmer. 1999. Computer Models for Masked Hearing Experiments with Beluga Whales ( Delphinapterus leuca s). Journal of the Acoustical Society of America 105:2967-2978.

Félix F, Haase B. 2001. Towards an estimate of the so utheastern Pacific humpback whale stock. Journal of Cetacean Research and Management 3(1):55-58.

Finneran, J.J.; C.E. Schlundt; R. Dear; D.A. Carder; S.H. Ridgway. 2002. Temporary Shift in Masked Hearing Thresholds in Odontocetes after Exposure to Sing le Underwater Impulses from a Seismic Watergun. J. Acoustical Society of America 108(1):2929-2940.

Forney KA, Barlow J, Muto MM, Lowry M, Baker J, Camero n G, Mobley J, Stinchcomb C, Carretta JV. 2000. U.S.Pacific Marine Mammal Stock Assessments:2000. Report nr NOAA Technical Memorandum NOAA-TMNMFS-SWFSC-300. 276 p.

Fraker, M.A. 1984. Balaena mysticetus: Whales, Oil, and Whaling in the Ar ctic. Anchorage, AK: Sohio-Alaska Petroleum Company and BP Alaska Exploration, Inc.

Fraker, M.A., D.K. Ljungblad, W.J. Richardson, and D. R. Van Schoik. 1985. Bowhead Whale Behavior in Relation to Seismic Exploration, Alaskan Beaufort Sea, Autumn 1981. OCS Study, MMS 85-0077. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 40 pp.

Funk, D., D. Hannay, D. Ireland, R.Rodriguez, W. Koski (eds.). 2008. Marine mammal monitoring and mitigation during open water seismic exploration by Shell Offs hore, Inc. in the Chukchi and Beaufort Seas, JulyNovember 2007; 90 day report. LGL Rep. P969-1. rep. from LGL Alaska Research Associated Inc., LGL Ltd., and JASCO Research Ltd. For Shell Offshore Inc., Nat. Mar. Fish. Serv., and U.S. Fish and Wildlife Serv. 218 p.

Gambell R. 1985. Fin whale Balaenoptera physalus (Linnaeus, 1758). p. 171-192. In: Ridgway SH, Harrison R,

122editors. Handbook of Marine Mammals. Vol. 3. The Sirenians and Baleen Whales. London, U.K.: Academic Press. p 362.

Gambell, R. 1993. International management of whales and whaling: an historical review of the regulation of commercial and aboriginal subs istence whaling. Arctic 46:97 B 107.

Gaskin DE. 1972. Whales, dolphins, and seals; with special reference to the New Zealand region.

Gausland, I. 1998. Physics of Sound in Water. Chapter 3. In: Proceedings of the Seismic and Marine Mammals Workshop, London, Jun. 23-25, 1998, M.L. Tasker and C. Weir, eds. Published on the web.

George, J.C., C. Clark, G.M. Carro ll, and W.T. Ellison. 1989. Observ ations on the Ice-Breaking and Ice Navigation Behavior of Migrating Bowhead Whales ( Balaena mysticetus ) near Point Barrow, Alaska, Spring 1985. Arctic 42(1):24-30.

George, J.C., J. Bada, J.E. Zeh, L. Scott, S.E. Brown, T. O’Hara, and R. S. Suydam. 1999. Age and Growth Estimates of Bowhead Whales ( Balaena mysticetus ) via Aspartic Acid Racemization. Canadian Journal of Zoology 77(4):571-580.

George, J.C., R.S. Suydam, L.M. Philo, T.F. Albert, J.E. Zeh, and G.M. Carroll. 1995. Report of the Spring 1993 Census of Bowhead Whales, Balaena msticetus, off Point Barrow, Alaska, with Observations on the 1993 Subsistence Hunt of Bowhead Whales by Alaska Eskimos. Reports of the International Whaling Commission 45. Cambridge, UK: IWC, pp. 371-384.

George, J.C., R. Zeh, R.P. Suydam, and C. Clark. 2004. Abundance and Population Trend (1978-2001) of Western Arctic Bowhead Whales Survey ed near Barrow, Alaska. Marine Mammal Science 20(4):755-773.

Geraci, J.R. 1988. Physiological and Toxic Effects on Cetaceans. In : Synthesis of Effects of Oil on Marine Mammals, J.R. Geraci and D.J. St. Aubin, eds. Washington, DC: USDOI, MMS.

Geraci, J.R., 1990. Ph ysiologic and Toxic Effects on Cetaceans. In: Sea Mammals and Oil: Confronting the
Risks, J.R. Geraci and D.J. St. Aubin, eds. San Dieg o, CA: Academic Press, Inc., and Harcourt Brace Jovanovich, pp. 167-197.

Geraci, J.R. and D.J. St. Aubin. 1982. Study of the Effects of Oil on Cetacean s. Final report. Washington, DC: USDOI, BLM, 274 pp.

Geraci, J.R. and D.J. St. Aubin. 1985. Expanded Studies for the Effects of Oil on Cetaceans. Part 1. Washington, DC: USDOI, MMS, 144 pp.

Geraci, J.R. and D.J. St. Aubin, eds. 1990. Sea Mammals and Oil: Confronting the Risks. San Diego, CA: Academic Press, 282 pp.

Geraci, J.R. and T.G. Smith. 1976. Direct and Indirect Effects of Oil on Ringed Seals ( Phoca hispida ) of the

Beaufort Sea. Journal of the Fisheries Resource Board of Canada 33:1976-1984.

Gerber, L.R. and D.P. DeMaster. 1999. A Quantitative Approach to Endangered Species Act Classification of Long-Lived Vertebrates: Application to the North Pacific Humpback Whale. Conservation Biology 17(3):1-12.

Gordon, J.C., D.D. Gille spie, J. Potter, A. Franzis, M.P. Simmonds, an d R. Swift. 1998. The Effects of Seismic Surveys on Marine Mammals. Chapter 6. In : Proceedings of the Seismic and Marine Mammals Workshop, London, Jun. 23-25, 1998, L. Tasker and C. Weir, eds. Published on the web.

Gordon, J.; D. Gillespie; J. Potter; A. Frantzis; M.P. Simmonds; R. Swift; D. Thompson. 2004. A Review of the Effects of Seismic Surveys on Marine Mammals. Marine Technology Society Journal 37(4):16.

123Gough W.A. 1998. Projections of Sea-Level Change in Hudson and James Bays, Canada, Due to Global Warming. Arctic and Alpine Research 30(1):84-88.

Greene, C.R. 1997. Underice Drillr ig Sound, Sound Transmission Loss, and Ambient Noise near Tern Island, Foggy Island Bay, Alaska, February 1997. Greeneridge Report 187-1. Santa Barbara, CA: Greeneridge Sciences, Inc., 22 pp.

Greene, C.R. 1998. Underwater Acoustic Noise and Transmission Loss During Summer at BP’s Liberty Prospect in Foggy Island Bay, Alaskan Beaufo rt Sea. Greenridge Repo rt 189-1. Santa Barbara, CA: Greeneridge Sciences, Inc., 39 pp.

Greene CR, Jr., Altman NS, Richardson WJ. 1999. Bowhead whale calls. p. 6-1 to 6-23 In: W.J. Richardson (ed.), Marine mammal and acoustical monitoring of Western Geophysical's open-water seismic program in the Alaskan Beaufort Sea, 1998. LGL Ltd., King City, On t., and Greeneridge Sciences Inc., Santa Barbara, CA, for Western Geophysical, Houston, TX, and U.S. Nat. Mar. Fish. Serv., Anchorage, AK, and Silver Spring, MD. Report nr LGL Rep. TA2230-3. 390 p.

Greene, C.R. Jr. 2003. An Assessment of the Sounds Li kely to be Received from a Tug-and-Barge Operating in

the Shallow Alaskan Beaufort Sea. Anchorage, AK: ConocoPhillips.

Greene, C.R., Jr. and M.W. McLennan. 2001. Acoustic Monitoring of Bowhead Whale Migration, Autumn 2000.

In: Monitoring of Industrial Sounds, Seals, and Whale Calls During Construction of BP’s Northstar Oil Development, Alaskan Beaufort Sea, Summer and Autumn 2000: 90-Day Report, LGL and Greeneridge, eds. LGL Report TA 2431-1. King City, Ont., Canada : LGL Ecological Research Associates, Inc., 37pp.

Greene, C.R., Jr., N.S. Altman, W. J. Richardson, and R.W. Blaylock . 1999. Bowhead Whale Calls. In: Marine Mammal and Acoustical Monitoring of Western Ge ophysical’s Open-Water Seismic Program in the Alaskan Beaufort Sea, 1998, LGL and Greeneridge, ed. LGL Report TA 2230-3. King City, Ont., Canada: LGL Ecological Research Assocs., Inc., 23 pp.

Griffiths, W.B. 1999. Zooplankton. In: Bowhead Whale Feeding in the Easter n Alaskan Beaufort Sea: Update of Scientific and Traditional Information. Retrospec tive and 1998 Results, W.J. Richardson and D.H. Thomson, eds. LGL Report TA- 2196- 2. King City, Ont., Canada: LGL Ecological Research Associates, Inc., 57 pp.

Griffiths, W.B., Thomson, D. H., and Bradstreet, M. S. W. 2002. Zooplankton and Water Masses at Bowhead Whale Feeding Locations in th e Eastern Beaufort Sea. In : Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Update of Scientific and Traditional Information, W. J. Richardson and D.H. Thomson, eds. LGL Report TA2196-7. King City, Ontario: LGL Limited, environmental research associates, pp. 1-44.

Hain JHW, Ratnaswamy MJ, Kenney RD, Winn HE. 1992. The fin whale, Balaenoptera physalus , in waters of the northeastern United States continental shelf. Report of the International Whaling Commission 42:653-669.

Haldiman, J., W. Henk, R. Henry, T.F. Albert, Y. Abdelb aki, and D.W. Duffield. 198 5. Epidermal and Papillary Dermal Characteristics of the Bowhead Whale ( Balaena mysticetus ). The Anatomical Record 211:391-

402.

Hall, J.D., M.L. Gallagher, K.D. Brewer, P.R. Regos, an d P.E. Isert. 1994. ARCO Alaska, Inc. 1993 Kuvlum Exploration Area Site Specific Monito ring Program. Final Report. Anchorage, AK: ARCO Alaska, Inc.

Hansbrough, J.F., R. Zapata-Sirvent, W. Dominic, J. Sullivan, J. Boswick, and X.W. Wang. 1985. Hydrocarbon Contact Injuries. The Journal of Trauma 25(3):250-252.

Hansen, D.J. 1985. The Potential Effects of Oil Sp ills and Other Chemical Pollutants on Marine Mammals

124Occurring in Alaskan Waters. OCS Report, MMS 85-0031. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 22 pp.

Hansen, D.J. 1992. Potential Effects of Oil Spills on Marine Mammals that Occu r in Alaskan Waters. OCS Report, MMS 92-0012. Anchorage, AK: US DOI, MMS Alaska OCS Region, 25 pp.

Harvey, J.T. and M.E. Dahlheim. 1994. Cetaceans in Oil. In: Marine Mammals and the Exxon Valdez, T.R. Loughlin, ed. San Diego, CA: Academic Press, pp. 257-264.

Henk, W.G. and D.L. Mullan. 1997. Common Epidermal Lesions of the Bowhead Whale ( Balaena mysticetus ). Scanning Microscopy Intl. 10(3):905-916.

Hill PS, DeMaster DP, Small RJ. 1997. Alaska Marine Mammal Stock Assessments, 199 6. U.S. Dep. Commerce. Report nr NOAA Tech. Memo. NMFS-AFSC.

Hoekstra, K.A., L.A. Dehn, J.C. George, K.R. Solomon, T.M. O’Hara, and D.C.G. Muir. 2002. Trophic Ecology of Bowhead Whales ( Balaena mysticetus ) Compared with that of Other Arctic Marine Biota as Interpreted from Carbon-, Nitrogen-, and Sulphur-Isotope Signatures. Canadian Journal of Zoology 80(2):223-231.

Hoffman, B. 2002. Testimony to PEW Oceans Commission Feb.-Mar. 2002.

Holst, M., G.W. Mille, V.D. Moulton, and R.E. Elliott. 2002. Aerial Monitoring, 2001. In: Marine Mammal and Acoustical Monitoring of Anderson Exploration Limited’s Open-Water Seismic Program in the Southeastern Beaufort Sea, 2001, LGL and JASCO Research Ltd., eds. LGL Report TA 2618-1. King City, Ont., Canada: LGL Ecological Re search Associates, Inc., 207 pp.

Hoyt, E. 1984. The whale watcher

= s handbook. Madison Press, Toronto, Ontario, Canada. 208 pp.

International Whaling Commission. 1987. Annex G: Report of the Subcommittee on Protected Species and Aboriginal Subsistence Whaling. Reports of the International Whaling Commission 37. Cambridge, UK:

International Whaling Commission. 1995. Report of the Scientific Committee. Rep. int. Whal. Commn 45:53 B 221.

International Whaling Commission. 2003a. Annex F. Report of the Sub-Commitee on Bowhead, Right and Gray Whales. Cambridge, UK: IWC.

International Whaling Commission. 2004a. Annex K. Report of the Standing Working Group on Environmental Concerns. Cambridge, UK: IWC.

International Whaling Commission. 2004b. Report of th e Sub-Committee on Bowhead, Right and Gray Whales. Cambridge, UK: IWC, 27 pp.

International Whaling Commission. 2005a. Report of the Scientific Committee. Cambridge, UK: IWC.

International Whaling Commission. 2005b. Annex F. Report of the Sub-Committee on Bowhead, Right and Gray Whales. Report 13:23. Camb ridge, UK: IWC, 12 pp.

International Whaling Commission. 2005c. In : Report of the Sub-Committee on Aboriginal Subsistence Whaling. Report of the International Whaling Commission 3. Cambridge, UK: IWC.

International Whaling Commission. 2007. Annex F. Report of the Sub-Committee on Bowhead, Right and Gray

Whales. http://www.iwcoffice.org/sci_com/screport.htm#report [accessed October 24, 2007]

IPCC. 2001a. Summar y for Policymakers. In : Climate Change 2001: Synthesis Report, Wembly, UK, Sept. 24-

125IPCC, 2007: Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp.

Jensen, A. S., and G. K. Silber. 2003. Large Whale Sh ip Strike Database. U.S. Dep. Commerce, NOAA Technical Memorandum NMFS-F/OPR-25, 37 pp.

Johannessen, O.M., E.V. Shalina, and M.W. Miles. 1999. Satellite Evidence for an Arctic Sea Ice Cover in

Transformation. Science 2865446:312-314.

Johnson, J.H. and A.A. Wolman. 1984. The Hu mpback Whale, Megaptera novaeangliae. Marine Fisheries

Review 46(4):300-337.

Johnson, S.R., C.R. Greene, R.A. Davis, and W.J. Richar dson. 1986. Bowhead Whales and Underwater Noise near the Sandpiper Island Drillsite, Alaskan Beaufort Sea, Autumn 1985. King City, Ont., Canada: LGL

Limited Environmental Resear ch Associates, 130 pp.

Johnston, R.C. and B. Cain. 1981. Marine Seismi c Energy Sources: Acoustic Performance Comparison. Manuscript presented at the 102 nd Meeting of the Acoustical Society of America, Miami, Fla., Dec. 1981, 35 pp.

Jurasz, C. M. and V. Jurasz. 1979. Feeding modes of the humpback whale, Megaptera novaeanglia e, in southeast Alaska. Scientific Report of the Whales Research Institute of Tokyo 31:69-83.

Kastak, D., R.J. Schustermank, B.L. Southall, and C.J. Reichmuth. 1999. Underwater Temporary Threshold Shift Induced by Octave-Band Noise in Three Species of Pinniped. J. Acoustical Society of America 106(2):1142-1148.

Kastak, D., B.L. Southall, R.J. Schusterman, and C.R. Kastak. 2005. Underwater Temporary Threshold Shift in Pinnipeds: Effects of Noise Level and Duration. J. Acoustical Society of America 118(5):3154-3163.

Ketten, D.R. 1998. Marine Mammal Auditory Systems: A Summary of Audiometric and Anatomical Data and its Implications for Underwater Acou stic Impacts. NOAA-TM-NMFS-SWFSC-256. LaJolla, CA: USDOC, NOAA, NMFS, Southwest Fisheries Science Center, 74 pp.

Ketten, D.R., J. Lien, and S. Todd. 1993. Blast Inju ry in Humpack Whale Ears: Evidence and Implications. J.

Acoustic Soc. America 943(Pt. 2):1849-1850.

Ketten DR. 1997. Structure and function in whale ears. Bioacoustics 8:103-135.

Khan, S., M. Martin, J.F. Payne, and A.D. Rahimtula. 1987. Embryonic Evaluation of a Prudhoe Bay Crude Oil in

Rats. Toxicology Letters 38:109-114.

Koski, W.R. 2000. Bowheads: Summary. In: Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Update of Scientific and Traditional Information. Results of Studies Conducted in Year 3, W.J. Richardson and D.H. Thomson, eds. LGL Report TA 2196-5. King City, Ont., Canada: LGL Limited, environmental research associates, pp. 1-4.

Koski, W.R. and S.R. Johnson. 1987. Behavioral Studies and Aerial Photogrammetry. In: Responses of Bowhead Whales to an Offshore Drilling Operation in the Alaskan Beaufort Sea, Autumn 1986. Anchorage, AK: Shell Western E&P, Inc.

Koski, W.R., G.W. Miller, and W.J. G azey. 2000. Residence Times of Bowh ead Whales in the Beaufort Sea and Amundsen Gulf During Summer and Autumn. In: Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Update of Scientific and Traditional Information. Results of Studies Conducted in Year 3,

126W.J. Richardson and D.H. Thomson, eds. LGL Report TA- 2196-5. King City, Ont., Canada: LGL Limited, environmental resear ch associates, pp. 1-12.

Koski, W.R., R.A. Davis, G.W. Miller, an d D.E. Withrow., 1993. Reproduction. In: The Bowhead Whale , J.J. Burns, J.J. Montague and C.J. Cowles, eds. Special Publication of The Society for Marine Mammalogy, 2. Lawrence, KS: The Society for Marine Mammalogy, pp. 239-274.

Koski, W.R., T.A. Thomas, G.W. Miller, R.E. Elliot, R.A. Davis, and W.J. Richardson. 2002. Rates of Movement

and Residence Times of Bowhead Wh ales in the Beaufort Sea and Am undsen Gulf During Summer and

Autumn. In : Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Update of Scientific and Traditional Information, W.J. Richardson and D. H. Thomson, eds. OCS Study, MMS 2002-012. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 41 pp.

Kraus, S., A. Read, E. Anderson, K. Ba ldwin, A. Solow, T. Spradlin, and J. Williamson. 1997. A Field Test of the

Use of Acoustic Alarms to Reduce Incidental Mortality of Harbor Porpoise in Gill Nets. Nature 388:341.

Ladich, F. and A. N. Popper. 2004. Parallel evolution in fish hearing organs. In: Evolution of the vertebrate auditory system, edited by G.A. Manley, A.N. Popp er, and R. R. Fay (Springer-Verlag, New York), 98-

127.

Laidre, Kristin L., I. Stirling, L.F. Lo wry, O. Wiig, M.P. Heide-Jorgensen, and S.H. Ferguson, 2008. Quantifying the sensitivity of arctic marine mammals to climate- induced habitat change. Ecol Appl. 18 (2). 28p.

Lambertsen, R.H. 1992. Crassicaudosis: A Parasitic Di sease Threatening the Health and Population Recovery of Large Baleen Whales. Rev. Sci. Technol. Off. Int. Ejpizoot. 11(4):1131-1141.

Lambertsen, R.H., K.J. Rasmussen, W.C. Lancaster, and R.J. Hintz. 2005. Functional Morphology of the Mouth of the Bowhead Whale and its Impl ications for Conservation. Journal of Mammalogy 86:2342-352

Leatherwood S, Reeves RR, Perrin WF, Evans WE. 1982. Whales, dolphins, and porpoises of the eastern North Pacific and adjacent arctic waters: a guide to thei r identification. NOAA Tech. Rep.: National Marine Fisheries Service. Report nr Circular 444.

Lee, S.H. and D.M. Schell. 2002. Regional and Seasonal Feeding by Bowh ead Whales as Indicated by Stable Isotope Ratios. In : Bowhead Whale Feeding in the Eastern Alas kan Beaufort Sea: Update of Scientific and Traditional Information, W.J. Richardson and W. J. Thomson, eds. LGL Report TA2196-7. King City, Ontario: LGL Limited, environmen tal research associates, pp. 1-28.

Lee, S.H., D.M. Schell, T.L. McDonald, and W.J. Richardson. 2005. Regional and Seasonal Feeding by Bowhead

Whales Balaena mysticetus as Indicated by Stable Isotope Rations. Mar. Ecol. Prog. Ser. (2005) 285:271-

287.

LGL Ltd., environmental research associates. 2001. Re quest by WesternGeco, LLC, for an Incidental Harassment

Authorization to Allow the Incidental Take of Whal es and Seals During an Open-Water Seismic Program in the Alaskan Beaufort Sea, Summer-Autumn 2001. King City, Ont., Canada: LGL.

Lien, J. 1994. Entrapments of large cetaceans in passive inshore fishing ge ar in Newfoundland and Labrador (1979 B 1990). Rep. int. Whal. Commn (Spec. Iss. 15):149 B 157.

Lillie, H. 1954. Comments in Discussion. In : Proceedings of th e International Confer ence on Oil Pollution, London, pp. 31-33.

Ljungblad, D.K., S.E. Moore, D.R. Van Schoik, and C.S. Winchell. 1982. Aerial Surveys of Endangered Whales in the Beaufort, Chukchi, and Northern Bering Seas. NOSC Technical Report 486. Washington, DC: USDOI, BLM, 374 pp.

127Ljungblad, D.K., S.E. Moore, J.T. Clar ke, D.R. Van Schoik, and J.C. Bennett. 1985. Aerial Surveys of Endangered Whales in the Northern Bering, Ea stern Chukchi, and Alaska Beaufort Seas, 1984: With a Six Year Review, 1979-1984. OCS Study, MMS 85-0018. NOSC Technical Report 1046. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 312 pp.

Ljungblad, D.K., S.E. Moore, J.T. Clarke, and J.C. Bennett. 1988. Distribution, Abundance, Behavior, and Bioacoustics of Endangered Whales in the Western Beaufort and Northeastern Chukchi Seas, 1979-87. OCS Study, MMS 87-0122. NOSC Technical Report 1232. Anchorage, AK: USDOI, MMS, 213 pp.

Loughlin, T.R. 1994. Marine Mammals and the Exxon Valdez. San Diego, CA: Academic Press, Inc.

Lowry, L.F. 1993. Foods and Feeding Ecology. In: The Bowhead Whale , J.J. Burns, J.J. Montague and C.J. Cowles, eds. Special Publication of The Society for Marine Mammalogy , 2. Lawrence, KS: The Society for Marine Mammalogy, pp. 201-238.

Lowry, L.F. and K.J. Frost. 1984. Foods and Feeding of Bowhead Whales in Western and Northern Alaska. Scientific Reports of the Whales Research Institute 35 1-16. Tokyo, Japan: Whales Research Institute.

Lowry, L.F. and G. Sheffield. 2002. Stomach Contents of Bowhead Whales Harvested in the Alaskan Beaufort

Sea. In: Bowhead Whale Feeding in the Eastern Alaska n Beaufort Sea: Update of Scientific and Traditional Information, LGL and Greeneridge, eds. LG L Report TA 2196-6. King City, Ont., Canada: LGL Ecological Research Associates, Inc., 28 pp.

Lowry, L.F., G. Sheffield, and J.C. George. 2004. Bowh ead Whale Feeding in the Alaskan Beaufort Sea, Based on Stomach Contents Analyses. J. Cetacean Res. Manage. 6(3):223.

Malme CI, Miles PR. 1985. Behavioral responses of marine mammals (gray whales) to seismic discharges. In: Greene GD, Engelhardt FR, Paterson RJ, editors. Proc. Workshop on effects of explo-sives use in the marine environment, Jan. 1985, Halifax, N.S. Tech. Rep. 5. Ottawa, Ont.: Can. Oil & Gas Lands Admin., Environ. Prot. Br. p 398.

Majors, M. 2004. Email dated Feb.24, 2004, from M. Majors, ConocoPhillips Alaska, Inc. to F. King, MMS Alaska OCS Region; subject: ConocoPhillips barge traf fic presentation Puviaq Barging Presentation.

Maslanki, J.A., M.C. Serreze, and R.G. Barry. 1996. R ecent Decreases in Arctic Summer Ice Cover and Linkages to Atmospheric Circulation Anomalies. Geophysical Research Letters 23(13):1677-1680.

Mate, B.R., G. K. Krutzikowsky, and M.H. Winsor. 2000. Satellite-Monitored Movements of Radio-Tagged

Bowhead Whales in the Beaufort and Chukchi Seas During the Late-Summer Feeding Season and Fall Migration. Canadian Journal of Zoology 78:1168-1181.

Maybaum, H.L. 1990. Effects of a 3. 3 kHz Sonar System on Humpback Whales, Megaptera novaeangliae , in

Hawaiian Waters. EOS 71(2):92.

McCauley RD, Jenner MN, Jenner C, McCabe KA, Murdoch J. 1998. The response of humpback whales ( Megaptera novangliae ) to offshore seismic survey noise: preliminary results of observations about a working seismic vessel and experimental exposures. Austral. Petrol. Product. Explor. Assoc. Journal

38:692-707.

McCauley, R.D., J. Fewtrell, A.J. Duncan, C. Jenner, M.-N . Jenner, J.D. Penrose, R.I. T. Prince, A. Adhitya, J. Murdoch, and K. McCabe. 2000. Marine Seismic Surveys: Analysis and Propagation of Air-Gun Signals; and Effects of Air-Gun Exposure on Humpback Whales, Sea Turtles, Fishes and Squid. Report R99-15, Project CMST 163. Curtin, Western Austra lia: Australian Petroleum Production Exploration

Assoc.

128McDonald, M.A., J.A. Hildebrand, S. Webb, L. Dorman, and C.G. Fox. 1993. Vocalizations of blue and fin whales during a midocean ridge airgun experiment. J. Acoust. Soc. Am. 94(3, pt. 2):1849.

McDonald, M.A., J.A. Hildebrand, and S.C. Webb. 1995. Blue and Fin Whales Observed on a Seafloor Aray in

the Northeast Pacific. J. Acoust. Soc. Am. 982(Pt. 1):712-721.

McDonald MA, Hildebrand JA, Webb SC. 1995a. Blue and fin whales observed on a seafloor array in the northeast

Pacific. Journal of the Acoustical Society of America 98:712-721.

McDonald MA, Hildebrand JA, Webb SC. 1995b. Blue and fin whales observed on a seafloor array in the Northeast

Pacific. Journal of the Acoustical So ciety of America 98(2Pt.1):712-721.

McDonald, M.A. and C.G. Fox. 1999. Passive Acoustic Methods Applied to Fin Whale Population Density

Estimation. J. Acoust. Soc. Am. 105(5):2643-2651.

Mel’nikov, V.V., M.A. Zelensky, and L.I. Ainana. 1997. Observations on Distribution and Migration of Bowhead Whales ( Balaena mysticetus ) in the Bering and Chukchi Seas. Scientific Report of the International Whaling Commission 50. Cambridge, UK: IWC.

Melnikov, V., M. Zelensky, and L. Ainana, 1998. Observations on distribution and migration of bowhead whales (Balaena mysticetus) in the Bering an d Chukchi Seas. IWC Paper SC/50/AS 3, IWC Scientific Committee, Oman, 1998. 31p.

Mel’nikov, V.V.; D.I. Litovka; I.A. Zagrebin; G.M. Zelens ky; L.I. Ainana. 2004. Shore-Based Counts of Bowhead Whales along the Chukotka Peninsula in May and June 1999-2001. Arctic 57(3):290-298.

Meredith GN, Campbell RR. 1988. Status of the fin whale, Balaenoptera physalus , in Canada. Canadian FieldNaturalist 102:351-368.

Michaud, R., and J. Giard. 1998. VHF tracking of fin whales provide scientific ground for the management of whale watching in the St. Lawrence estuary. World Marine Mammal Science Conference, Monaco, January 1998. Abstracts, p. 91.

Miles, P.R., C.I. Malme, and W.J. Rich ardson. 1987. Prediction of Drilling S ite-Specific Interaction of Industrial Acoustic Stimuli and Endangered Whales in the Alas kan Beaufort Sea. OCS Study, MMS 87-0084. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 341 pp.

Miller, G.W. 2002. Seismic Program Described, 2001. In: Marine Mammal and Acoustical Monitoring of Anderson Exploration Limited’s Open-Water Seismic Program in the Southeaste rn Beaufort Sea, 2001, LGL and JASCO Research Ltd, eds. LGL Report TA 2618-1. King City, Ont., Canada: LGL Ecological Research Associates, Inc., 207 pp.

Miller, G.W. and R.A. Davis. 2002. Marine Mammal and Acoustical Monitoring of Anderson Exploration Limited’s Open-Water Seismic Program in the Southeaste rn Beaufort Sea, 2001. LGL Report TA 2618-1. King City, Ont. Canada: LGL Ecological Research Associates, Inc., 199 pp.

Miller, G.W., R.E. Elliott, and W.J. Ri chardson. 1996. Marine Mammal Distribution, Numbers and Movements.

In: Northstar Marine Mammal Monitoring Program, 19 95: Baseline Surveys and Retrospective Analyses of Marine Mammal and Ambient Noise Data from the Central Alaskan Beaufort Sea. LGL Report TA 2101-2. King City, Ont., Canada: LGL Ecological Research Associates, Inc., pp 3-72.

Miller, G.W., R.E. Elliott, and W.J. Richardson. 1998 . Whales. In : Marine Mammal and Acoustical Monitoring of BP Exploration (Alaska)’s Open-Water Seismic Pr ogram in the Alaskan Beaufort Sea, 1997, LGL and Greeneridge, eds. LGL Report TA 2150-3. King City, Ont., Canada: LGL Ecological Research Associates, Inc., 124 pp.

129Miller, G.W., R.E. Elliott, W.R. Koski, and W.J. Rich ardson. 1997. Whales. In: Northstar Marine Mammal Monitoring Program, 1996: Marine Mammal and Acoustical Monitoring of a Seismic Program in the Alaskan Beaufort Sea, LGL and Greeneridge, eds. LGL Report TA 2121-2. King City, Ont., Canada: LGL Ecological Research Associates, Inc. , 115 pp.

Miller, G.W., R.E. Elliott, W.R. Koski, V.D. Moulton, and W.J. Richardson. 1999. Whales. In: Marine Mammal and Acoustical Monitoring of Western Geophysical ’s Open-Water Seismic Program in the Alaskan Beaufort Sea, 1998, LGL a nd Greeneridge, eds. LGL Report TA 2230-3. King City, Ont., Canada: LGL Ecological Research Asso ciates, Inc., 109 pp.

Miller, G.W., R.A. Davis, V.D. Moulton, A. Serrano, and M. Holst. 2002. Integration of Monitoring Results, 2001.

In : Marine Mammal and Acoustical Monitoring of Anderson Exploration Limited’s Open-Water Seismic Program in the Southeastern Beaufort Sea, 2001, LGL and JASCO Research Ltd. LGL Report TA 2618-1. King City, Ontario, Canada: LGL Ecological Research Associates, Inc., 207 pp.

MMS, 2005. Chukchi sea planning area oil and gas lease sale 193 and seismic surveying activities in the Chukchi Sea. Final environmental impact statement. U.S. Mi nerals Management Service, USDOI, Alaskan OCS office, Anchorage, AK.

M itchell, E., and R.R. Reeves. 1983. Catch history, abundance, and present status of northwest Atlantic humpback whales. Rep. int. Whal. Commn (Spec. Iss. 5):153 B 212.

Mizroch, S.A., D.W. Rice, D. Zwiefelhofer, J. Waite, and W.L. Perryman. In prep. Distribution and Movements of

Monnett, C. and L.M. Rotterman. 1989. Movement Patterns of Western Alaska Peninsula Sea Otters. In : Proceedings of the Gulf of Alaska, Cook Inlet, an d North Aleutian Basin Info rmation Update Meeting, Anchorage, Feb. 7-8 1989, L.E. Jarvela and L.K. Thorsteinson, eds. Anchorage, AK: USDOI, MMS, Alaska OCS Region, pp. 121-128.

Monnett, C. and S.D. Treacy. 2005. Aerial Surveys of Endangered Whales in the Be aufort Sea, Fall 2002-2004. OCS Study, MMS 2005-037. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

Moore, S.E. 1992. Summer R ecords of Bowhead Whales in th e Northeastern Chukchi Sea. Arctic 45(4):398-400.

Moore, S.E. and R.R. Reeves., 1993. Distribution and Movement. In: The Bowhead Whale , J.J. Burns, J.J. Montague, and C.J. Cowles, eds. Special Publication of The Society for Marine Mammalogy, 2. Lawrence, KS: The Society for Marine Mammalogy, 313-386.

Moore, S.E., J.C. George, K.O. Coyle, and T.J. Weingartner. 1995. Bowhead Whales Along the Chukotka Coast in

Autumn. Arctic 48(2):155-160.

Moore, S.E. and D.P. DeMaster. 2000. North Pacifi c Right Whale and Bowhead Whale Habitat Study: R/V Alpha

Helix and CCG Laurier Cruises, July 1999, A.L. Lopez and D.P. DeMaster, eds. Silver Spring, MD: NMFS, Office of Pr otected Resources.

Moore, S.E., D.P. DeMaster, and P.K. Dayton. 2000. Cetacean Habitat Sel ection in the Alaskan Arctic during

Summer and Autumn. Arctic 53(4):432-447.

Moore, Sue E. and K.R. Laidre. 2006. Trends in sea ice cover within hab itats used by bowhead whales in the western arctic. Ecol. Appl., 16 (3).12p.

Moore, S.E., K.E.W. Shelden, L.K. Litzky, B.A. Mohoney, and D.J. Rugh. 2000. Beluga, Delphinapterus leucas

, Habitat Associations in Cook Inlet, Alaska. Marine Fisheries Review 62(3):60-80.

Moore SE, Watkins WA, Daher MA, Davies JR, Dahlheim ME. 2002. Blue whale habitat associations in the

130Northwest Pacific: analysis of remotely-sense d data using a Geographic Information System. Oceonagraphy 15(3):20-25.

Mössner, S. and K. Ballschmiter. 1997. Marine Mammals as Global Pollution Indicators for Organochlorines. Chemosphere 34(5-7):1285-1296.

Moyle, P. B. and J. J. Cech, Jr. 1988. Fishes: an introdu ction to ichthyology. Prentice-Hall, Inc. New Jersey 07632.

Nachtigall, P.E.; A.Y. Supin; J. Pawloski; W.W.L. Au. 2004. Temporary Threshold Shifts after Noise Exposure in the Bottlenose Dolphin ( Tursiops truncatus ) Measured using Evoked Auditory Potentials. Marine Mammal Science 20(4):673-687.

National Research Council. 2001. Climate Change Science: An Analysis of Some Key Questions. Washington, DC: National Academy Press.

National Research Council. 2003. Ocean Noise and Marine Mammals . Washington, DC: National Academy

Press.

National Research Council. 2005. Marine Mammal Populations and Ocean Noise. Determining When Noise Causes Biologically Significant Effects. Washington, DC: The National Academies Press.

Natural Resources Defense Council. 1999. Sounding the Depths. Supertankers, Sonar, and the Rise of Undersea Noise. Washington, DC: NRDC.

Natural Resources Defense Council. 2005. Sounding the Depths II: The Rising Toll of Sonar, Shipping and Industrial Ocean Noise on Marine Life. New York, NRDC.

Neff, J.M. 1990. Effects of Oil on Marine Mammal Populations: Model Simulations. In: Sea Mammals and Oil: Confronting the Risks, J.R. Geraci and D.J. St. Au bin, eds. San Diego, CA: Academic Press, Inc. and Harcourt, Brace Jovanovich, pp. 35-54.

Nemoto, T. 1970. Feeding pattern of baleen whales in the oceans. pp. 241B252 in Marine food chains, ed. J.H.

Steele. Univ. of Califor nia Press, Berkeley.

Nerini, M., H. Braham, W. Marquett, and D. Rugh. 1984. Life history of the bowhead whale, Balaena mysticetus (Mammalia: Cetacea). J. Zool. (Lond.)204(4).

Nieukirk, S.L., K.M. Stafford, D.K. Mellinger, R.P. Dz iak, and C.G. Fox. 2004. Low-Frequency Whale and Seismic Airgun Sounds Recorded in the Mid-Atlantic Ocean. J. Acoust. Soc. Am. 115(4):1832-1843.

Nishiwaki M. 1966. Distribution and mi gration of the larger cetaceans in the North Pacific as shown by Japanese whaling results. In: Norris KS, editor. Whales, Dolphins and Porpoises. Berkeley: University of California Press. p 171-191.

NMFS. 1991. Recovery plan for the humpback whale (M egaptera novaeangliae). Pr epared by the humpback recovery team for the National Marine Fisherie s Service, Silver Spri ng, Maryland. 105 pp.

NMFS. 1999. Endangered Species Act Section 7 Consultation (Biological Opinion) for the Proposed Construction and Operation of the Northstar Oil and Gas Project in the Alaskan Beaufort Sea. Anchorage, AK: NMFS, 75 pp.

NMFS. 2000. Recovery Plan for the Fin Whale (Balaenoptera physalus) and the Sei Whale (Balaenoptera borealis) . Office of Protected Resources, National Marine Fisheries Service, Silver Spring, Maryland. 38

pp.

131NMFS. 2001. Endangered Species Act Section 7 Consultation (Biological Opinion) for the Arctic Region for Federal Oil and Gas Leasing and Exploration in the Alaskan Beaufort Sea. Anchorage, AK: USDOC,

NMFS.

NMFS. 2002. Biological Opinion. Proposed Regulations to Authorize the Navy to Take Marine Mammals Incidental to its Employment of Surveillance Towed Array Sensor System Low Frequency Active Sonar. ESA Section 7 Consultations. Silver Spring , MD: NMFS, Office of Protected Species.

NMFS. 2003a. Biological Opinion on Issuance of Annual Quotas Authorizing the Harvest of Bowhead Whales to the Alaska Eskimo Whaling Commission for the Period 2003 through 2007. Anchorage, AK: USDOC,

NMFS.

NMFS. 2003b. Environmental Assessment for Issuing Annual Quotas to the Alaska Eskimo Whaling Commission for a Subsistence Hunt on Bowhead whales for the Years 2003 through 2007. Anchorage, AK: USDOC, NMFS, 67 pp. plus appendices.

NMFS. 2005. Endangered Species Act Section 7 Consultation Biological Opinion for the Kensington Gold Project. March 18, 2005. NMFS Alaska Region, Protected Resources Division, P. O. Box 21688, Juneau,

AK 99802.

NMFS 2006

. Draft recovery plan for the fin whale (Balaenoptera physalus). Na tional Marine Fisheries Service, Office of Protected Resources, Silver Spring, Maryland

NMFS. 2006. Biological Assessment of the Alaska Groundfish Fisheries and NMFS Managed Endangered Species Act Listed Marine Mammals and Sea Turtles. April 2006. NMFS Alaska Region, Sustainable Fisheries Division, P. O. Box 21688, Juneau, AK 99802.

Ohsumi S, Wada S. 1974. Status of whale stocks in the North Pacific, 1972. Report of the International Whaling

Commission 24:114-126.

Okal, E.A. and J. Talandier. 1986. T-Wave Duration, Magnitudes and Seismic Moment of an Earthquake-- Application to Tsunami Warning. J. Phys. Earth 34:19-42.

Payne RS. 1970. Songs of the humpback whale. Hollywood, USA: Capital Records.

Perry SL, DeMaster DP, Silber GK. 1999. The great whales: History and status of six species listed as endangered under the U.S. Endangered Species Act of 1973. Marine Fisheries Review 61(1):1-74.

Patenaude, N.J., M.A. Smultea, W.R. Koski, W.J. Richards on, and C.R. Greene. 1997. Aircraft Sound and Aircraft Disturbance to Bowhead and Beluga Whales During th e Spring Migration in the Alaskan Beaufort Sea. King City, Ont., Canada: LGL Ltd. Envir onmental Research Associates, 37 pp.

Patterson B, Hamilton GR. 1964. Repetitive 20 cycle per second biological hydroacoustic signals at Bermuda. In: Tavolga WN, editor. Marine bioacoustics.

Payne R, Webb D. 1971. Orientation by means of long range acoustic signaling in baleen whales. Ann. N.Y. Acad.

Sci. 188:110-141.

Peters, R.L. 1991. Consequences of Global Warming from Biological Diversity. In : Global Climate Change and Life on Earth , R.L. Wyman, ed. New York: Chapman and Hall, pp. 99-118.

Peters, R.L. and D.S. Darling. 1985. The Greenhouse Effect and Nature Reserves. Bioscience 35(11):707-717.

Philo, M., J.C. George, R. Suydam, T.F. Albert, and D. Ra mey. 1993. Report of Field Activities of the Spring 1992 Census of Bowhead Whales, Balaena mysticetus , off Point Barrow, Alaska with Observations on the

132Subsistence Hunt of Bowhead Whales 1991 and 1992. Report of the International Whaling Commission 44. Cambridge, UK: IWC, pp. 335-342.

Popper, A. N., R. R. Fay, C. Platt, and O. SAnd. 2003. "Sound detection mechanisms and capabilities of teleost fishes." In: Sensory Processing in Aquatic Environments, edited by S.P. Collins and N.J. Marshall. SpringerVerlag, New York, pp. 3-38.

Raftery, A.; J. Zeh; G. Givens. 1995. Revived Estimates of Bowhead Rate of Increase. Report of the International Waling Commission 45. Cambridge, UK: IWC, 158 pp.

Read, A.J. 1994. Interactions between cetaceans and gillnet and trap fisheries in the northwest Atlantic. Rep. int. Whal. Commn (Spec. Iss. 15):133 B 147.

Reese, C.S., J.A. Calvin, J.C. George, and R.J. Tarpley. 2001. Estimation of Fetal Growth and Gestation in Bowhead Whales. Journal of the American Statistical Association 96(455):915-923.

Reeves, R.R. 1992. Whale Responses to Anthropogenic Sounds: A Literature Review. Science & Research Series 47. Wellington, NZ: New Zealand De pt. of Conservation, 47 pp.

Reeves, R.R. and M.F. Barto. 1985. Whaling in the Bay of Fundy. Whalewatcher 19(4):14-18.

Reeves, R.R., and M.W. Brown. 1994. Marine mammals and the Canadian patrol frigate shock trials: a literature review and recommendations for mitigating the impacts. Final report by East Coast Ecosystems, Pierrefonds, Quebec, to National Defence Headquarters, Ottawa.

Rice DW. 1974. Whales and whale research in the eastern North Pacific. In: Schevill WE, editor. The Whale Problem: A Status Report. Cambridge, MA: Harvard University Press. p 419.

Richardson, W.J., ed. 1987. Importa nce of the Eastern Alaskan Beaufort Sea to Feeding Bowhead Whales 1985- 86. OCS Study, MMS 87-0037. Reston, VA: USDOI, MMS, 547 pp.

Richardson, W.J., ed. 1999. Marine Mammal and Acous tical Monitoring of Western Geophysical’s Open-Water Seismic Program in the Alaskan Beaufort Sea, 1998. LGL Report TA- 2230- 3. King City, Ont., Canada: LGL Ltd., environmental resear ch associates, 390 pp.

Richardson, W.J., ed. 2000. Marine Mammal and Acous tical Monitoring of Western Geophysical’s Open-Water Seismic Program in the Alaskan Beaufort Sea, 1999. LGL Report TA- 2313- 4. King City, ON, Canada: LGL Ltd., Environmental Resear ch Associates, 155 pp.

Richardson, W.J., ed. 2006. Monitoring of Western i ndustrial sounds, seals, and bowhead whales near BP’s Northstar oil development, Alaskan Beaufort Sea, 1999-2004. [Updated comprehensive reports, April, 2006.]. LGL Report TA- 4256A. Rep. from LGL ltd. (King City, Ont.), Greeneridge Sciences, Inc.,(Santa Barbara, CA) and WEST Inc. (Cheyenne, WY), for BP Explor. (Alaska) Inc., Anchorage, AK. 328p.

Richardson, W.J and C.I. Malme. 1993. Man-Made Noise and Behavioral Responses. In: The Bowhead Whale, J.J. Burns, J.J. Montague and C.J. Cowles, eds. Special Publication of The Society for Marine Mammalogy, 2. Lawrence, KS: The Societ y for Marine Mammalogy, pp. 631-700.

Richardson WJ, Würsig B, Greene CR. 1986. Reactions of bowhead whales, Balaena mysticetus , to seismic exploration in the Canadian Beaufort Sea. Journal of the Acoustical Society of America 79(4):1117-1128.

Richardson, W.J. and D.H. Thomson. 2002. Email dated Apr. 25, 2002, to S. Treacy, USDOI, MMS, Alaska OCS Region; subject: bowhead whale feeding study.

Richardson, W.J. and M.T. Williams, eds. 2003. Monitoring of Industrial Sounds, Seals, and Bowhead Whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2002. Anchorage, AK: BPXA and

133USDOC, NMFS.

Richardson, W.J. and M.T. Williams, eds. 2004. Monitoring of Industrial Sounds, Seals, and Bowhead Whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2003. Annual and Comprehensive Report. LGL Report TA 4001. Anchorage, AK: BPXA.

Richardson, W.J.; R.S. Wells; B. Wursig. 1985. Disturbance Responses of Bowheads, 1980-1984. In: Behavior, Disturbance Responses, and Distribution of Bowhead Whales, Balaena mysticetus , in the Eastern Beaufort Sea, 1980-84. OCS Study, MMS 85-0034. Anchorage, AK: USDOI, MMS, Alaska OCS Region, pp.

255-306.

Richardson, W.J., M.A. Fraker, B. Wursig, and R.S. Wells. 1985. Behavior of Bowhead Whales, Balaena mysticetus , Summering in the Beaufort Sea: Reactions to Industrial Activities. Biological Conservation 32(3):195-230.

Richardson WJ, Davis RA, Evans CR, Ljungblad DK, Norton P. 1987. Summer distribution of bowhead whales, Balaena mysticetus , relative to oil industry activities in the Canadian Beaufort Sea, 1980-84. Arctic 40(2):93-104.

Richardson, W.J., C.R. Greene, C.I. Malme, D.H. Thomson, S.E. Moore, and B. Wursig. 1991. Effects of Noise on Marine Mammals. OCS Study, MMS 90-0093. He rndon, VA: USDOI, MMS, Atlantic OCS Region, 462 pp.

Richardson, W.J., C.R. Greene, Jr., C.I. Malme, and D.H. Thomson. 1995a. Marine Mammals and Noise. San Diego, CA: Academic Press, Inc.

Richardson, W. J., C.R. Greene, J.S. Ha nna, W.R. Koski, G.W. Miller, N.J. Patenaude, and M.A. Smultea. 1995b. Acoustic Effects of Oil Production Activities on Bowhead and White Whales Visible During Spring Migration Near Point Barrow. OCS Study MMS 95-0051. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 452 pp.

Richardson, W.J., T.L. McDonald, C.R. Greene, and S.B. Blackwell. 2004. Acoustic Localization of Bowhead Whales near Northstar, 2001-2003: Evidence of Deflection at High-Noise Times? Chapter 8. In : Monitoring of Industrial Sounds, Seals, and Bowhead Whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2003, W.J. Richardson and M.T. Williams, eds. Anchorage, AK: BPXA.

Rothrock, D.A., Y. Yu, and G.A. Maykut. 1999. Thinning of the Arctic Sea-Ice Cover. Geophysical Research

Letters 2623:3469-3472.

Salden DR. 1987. An observation of apparent feeding by a sub-adult humpback whale off Maui.Eighth Biennial Conference on the Biology of Marine Mammals. Pacific Grove, CA. p58.

Scammon, C.M. 1874. The marine mammal s of the northwestern coast of North America. Together with an account of the American whale-fishery. John H. Carmany and Co., San Francisco.

Scheidat M, Castro C, Denkinger J, Gonzalez J, Ad elung D. 2000. A breeding area for humpback whales ( Megaptera novaeangliae ) off Ecuador. Journal of Cetacean Research and Management 2(3):165-171.

Schell, D.M. 1999a. Habitat Usage as Indicated by Stable Isotope Ratios. In: Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Update of Scientific and Traditional Information, W.J. Richardson and D.H. Thomson, eds. LGL Report TA 2196- 2. Herndon, VA: USDOI, MMS, pp. 179-192.

Schell, D.M. 1999b. North Pacific an d Bering Sea Carrying Capacity: A Hind cast and a Look at Changes Ahead.

In: Alaska OCS Region Seventh Info rmation Transfer Meeting Proceedings . OCS Study, MMS 99-0022. Anchorage, AK: USDOI, MMS, pp. 34.

134Schell, D.M. and S.M. Saupe., 1993. Feeding and Growth as Indicated by Stable Isotopes. In: The Bowhead
Whale, J.J. Burns, J.J Montague, and C.J. Cowles, eds. Special Publication of The Society for Marine Mammalogy, 2. Lawrence, KS: The Society for Marine Mammalogy, 491-509 pp.

Schell, D.M., S.M. Saupe, and N. Haubenstock. 1987. Bowhead Whale Feeding: Allocation of Regional Habitat Importance Based on Stable Isotope Abundances. In: Importance of the Eastern Alaskan Beaufort Sea to Feeding Bowhead Whales 1985-86, W.J. Richardson, ed. OCS Study, MMS 87-0037. Reston, VA: USDOI, MMS, pp. 369-415.

Schevill, W.E., W.A. Watkins, and R.H. Backus. 1964. The 20-cycle signals and Balaenoptera (fin whales). Pp. 147 B 152 in Marine Bio-acoustics C Proceedings of a symposium held at Bimini, Bahamas.

Schick, R.S. and D.L. Urban. 2000. Spatial Components of Bowhead Whales ( Balaena mysticetus ) Distribution in

the Alaskan Beaufort Sea. Canadian Journal of Fisheries Aquatic Science 57:2193-2200.

Schlundt, C.E., J.J. Finneran, D.A. Carder, and S.H. Ridgway. 2000 Temporary Shift in Masked Hearing Thresholds of Bottlenose Dolphins, Tusiops truncatus, and White Whale, Delphinapterus leucas , after Exposure to Intense Tones. J. Acoustical Society of America 107(6):3496-3508.

Schmitt, F.P., C. de Jong, and F.H. Winter. 1980. Thomas Welcome Roys. America's Pioneer of Modern Whaling. Univ. Press of Virginia, Charlottesville. 253 pp.

Sergeant DE. 1977. Stocks of fin whales, Balaenoptera physalus , in the North Atlantic Ocean. Report of the International Whaling Commission 27:460-473.

Shelden, K.E.W., D.P. DeMaster, D.J. Rugh, and A.M. Olson. 2001. Developing Classification Criteria under the U.S. Endangered Species Act: Bo whead Whales as a Case Study. Conservation Biology 15(5):1300-1307.

Shotts, E.B., T.F. Albert, R.E. Wooley, and J. Brown. 1990. Microflora Associated with the Skin of the Bowhead Whale ( Balaena Mysticetus ). Journal of Wildlife Diseases 26(3):351-359.

Sigurjónsson, J. 1988. Operational factors of the I celandic large whale fishery. Rep. int. Whal. Commn 38:327 B 333.

Silber GK. 1986. The relati onship of social vocalizations to surface behavior and aggression in the Hawaiian humpback whale ( Megaptera novaeangliae ). Canadian Journal of Zoology 64:2075-2080.

St. Aubin, D.J. 1988. Physiologic and Toxicologic Effects on Pinnipeds. Chapter 3. In: Synthesis of Effects of Oil on Marine Mammals, J.R. Geraci and J.D. St. Au bin, eds. OCS Study, MMS 88-0049. Vienna, VA: USDOI, MMS, Atlantic OCS Region, 292 leaves.

St. Aubin, D.J., R.H. Stinson, and J. R. Geraci. 1984. Aspects of the Structure and Composition of Baleen and Some Effects of Exposure to Petroleum Hydrocarbons. Canadian Journal of Zoology 62(2):193-198.

Stang, P.R. and J.C. George. 2003. Letter dated Aug. 27 , 2003, from P.R. Stang, Regional Supervisor, Leasing and Environment, MMS Alaska OCS Region and J.C. George, Wildlife Biologist, North Slope Borough Dept. of Wildlife Management to NSB Mayor Ahmaogak; subj ect: response to Mayor’s letter on coordination and cooperation with the North Slope Borough.

Stoker, S.W. and I.I. Krupnik., 1993. Subsistence Whaling. In: The Bowhead Whale, J.J. Burns, J.J. Montague, and C.J. Cowles, eds. Special Pub lications of the Society for Marine Mammalogy Publications, No. 2. Lawrence, KS: Society for Ma rine Mammalogy, pp. 579-629.

Stone, C.J., Comp. 2001. Marine Mammal Observations during Seismic Surveys in 1999. Aberdeen, UK: Joint Nature Conservation Committee, 69 pp.

135Stone, G.S., S.K. Katona, A. Mainwaring, J.M. Allen, and H. D. Corbett. 1992. Respiration and surfacing rates of fin whales ( Balaenoptera physalus ) observed from a lighthouse tower. Rep. int. Whal. Commn 42:739 B 745.

Strong CS. 1990. Ventilation patterns and behavior of balaen opterid whales in the Gulf of California, Mexico. MS thesis, San Francisco State University, CA.

Swingle WM, Barco SG, Pitchford TD. 1993. Appearance of juvenile humpback whales feeding in the nearshore waters of Virginia. Marine Mammal Science 9:309-315.

Tarpley, R.J., R.F. Sis, T.F. Albert, L.M. Dalton, and J.C. George. 1987. Observations on the Anatomy of the Stomach and Duodenum of the Bowhead Whale, Balaena Mysticetus. The American Journal of Anatomy

180:295-322.

Tasker, M.L., J. Karwatowski, P.G.H. Evans, and D. Thompson. 1998. Introduction to Seismic Exploration and

Marine Mammals in the North-East Atlantic. In : Proceedings of the Seismic and Marine Mammal Workshop, London, Jun. 23-25, 1995.

Taylor, M. 2003. Why the Bering-Chukchi-Beaufort Seas Bowhead Whale is Endangered: Response to Shelden et

al. Conservation Biology 17(3):915-917.

Taylor, B.L., R. LeDuc, C. George, R. Suydam, S.E. Moore and D.J. Rugh. 2007. Synthesis of lines of evidence for population structure for bowhead whales in the Bering-Chukchi- Beaufort region. SC/59/BRG35 unpublished doc submitted to the IWC SC, Anchorage, AK. 12p.

Tershy BR, Acevedo GA, Breese D, Strong CS. 1993. Diet and feeding behavior of fin and Bryde's whales in the central Gulf of California, Mexico. Rev Inv Cient 1((No Esp SOMEMMA 1)):31-38.

Thompson TJ, Winn HE, Perkins PJ. 1979. Mysticete sounds. In: Winn HE, Olla BL, editors. Behavior of Marine

Animals. Vol. 3. Cetaceans.

Thompson PO, Cummings WC, Ha SJ. 1986. Sounds, source levels, and associated behavior of humpback whales,

southeast Alaska. Journal of the Acous tical Society of America 80:735-740.

Thomson, D.H. and W.J. Richardson. 1987. Integration. In: Importance of the Eastern Alaskan Beaufort Sea to Feeding Bowhead Whales, 1985-86, W.J. Richardson, ed. OCS Study, MMS 87-0037. Reston, VA: USDOI, MMS, pp. 449-511.

Thomson, D.H., W.R. Koski, and W.J. Richardson. 2002. Integration and Conclusions. In : Bowhead Whale Feeding in the Eastern Alaskan Beaufort Sea: Upda te of Scientific and Traditional Information, W.J. Richardson and D.H. Thomson,eds. LGL Report TA2196-7. King City, Ontario: LGL Limited, environmental research associates, pp. 1-35.

Thompson PO, Findley LT, Vidal O. 1992. 20-Hz pulses and other vocalizations of fin whales, Balaenoptera physalus , in the Gulf of California, Mexico. Journal of the Acoustical Society of America 92:3051-3057.

Tolstoy, M., J.B. Diebold, S.C. Webb, D.R. Bohnenstiehl, E. Chapp, R.C. Holmes, and M. Rawson. 2004.

Broadband Calibration of R/V Ewing Seismic Sources. Geophysical Research Letters 31:L14310-L1314.

Tønnessen JN, Johnsen O. 1982. The history of modern whaling. Berkeley, California: University of California

Press.

Townsend, C.H. 1935. The Distribution of Certain Whales as Shown by Logbook Records of Certain Whaleships. Zoologica 1:1-50 plus 4 charts.

136Treacy, S.D. 1988. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1987. OC S Study, MMS 89- 0030. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 141 pp.

Treacy, S.D. 1989. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1988. OC S Study, MMS 89- 0033. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 101 pp.

Treacy, S.D. 1990. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1989. OC S Study, MMS 90- 0047. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 104 pp.

Treacy, S.D. 1991. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1990. OC S Study, MMS 91- 0055. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 107 pp.

Treacy, S.D. 1992. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1991. OC S Study, MMS 92- 0017. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 92 pp.

Treacy, S.D. 1993. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1992. OC S Study, MMS 93- 0023. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 135 pp.

Treacy, S.D. 1994. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1993. OC S Study, MMS 94- 0032. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 78 pp.

Treacy, S.D. 1995. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1994. OC S Study, MMS 95- 0033. Anchorage, AK: USDOI, MMS, Alaska OCS Region, Environmental Studies, 116 pp.

Treacy S.D. 1996. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1995. OC S Study, MMS 96- 0006. Anchorage, AK: USDOI,.MMS, Alaska OCS Region, Environmental Studies Program, 70 pp.

Treacy, S.D. 1997. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1996. OC S Study, MMS 97- 0016. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 115 pp.

Treacy, S.D. 1998. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1997. OC S Study, MMS 98- 0059. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 143 pp.

Treacy, S.D. 2000. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 1998-1999 . OCS Study, MMS 2000-066. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 135 pp.

Treacy, S.D. 2001. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 2000. OC S Study, MMS 2001- 014. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 111 pp .

Treacy, S.D. 2002. Aerial Surveys of Endangered Whales in the Beaufort Sea, Fall 2001. OC S Study, MMS 2002- 061. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 117 pp.

Tyack P. 1981. Interactions between singing Hawaiian humpback whales and conspecifics nearby. Behavioral Ecology and Sociobiology 8:105-116.

Tyack P, Whitehead H. 1983. Male competition in large groups of wintering humpback whales. Behaviour 83:132-

154.

Tyack PL. 1999. Functional aspects of cetacean communicati on. In: Mann J, Conner RC, Tyack PL, Whitehead H, editors. Cetacean Societies: Field Studies of Dolphins and Whales. Chicago: University of Chicago Press.

U.S. Army Corps of Engineers. 1999. Final Envir onmental Impact Statement. Beaufort Sea Oil and Gas Development/Northstar Project. Anchorage, AK: U.S. Army Corps of Engineers, 7 Vols.

USDOC, NOAA and North Slope Borough. 2005. Workshop of Bowhead Whale Stock Structure Studies in the

137Bering-Chukchi-Beaufort Seas: 2005-2006, Seattle, Wash., Feb. 23-24, 2005. Seattle, WA and Barrow, AK: USDOC, NOAA, AFSC/NMML and NSB.

USDOC, NOAA. 2008. Final environmental impact statement for issuing annual quotas to the Alaska Eskimo Whaling Commission for a subsistence hunt on bowhead whales for the years 2008 through 2012. 259p.

USDOI, MMS. 1995. Public Hearing, Official Transcript of Proceedings, Beaufort Sea Sale 144 Draft EIS, Barrow, Ak., Nov. 8, 1995. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

USDOI, MMS. 1996. Nuiqsut Community Meeting, Aug. 14, 1996. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

USDOI, MMS. 1997. Arctic Seismic Synthesis and Mitiga ting Measures Workshop, Barrow , Ak., Mar. 5-6, 1997. Whalers’ signed statement. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

USDOI, MMS. 2003a. Beaufort Sea Planning Area Sales 186, 195, and 202 Oil and Gas Lease Sale Final EIS. OCS EIS/EA, MMS 2003-001. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

USDOI, MMS. 2003b. Cook Inlet Planning Area Oil and Gas Lease Sales 191 and 199 Final EIS. OCS EIS/EA, MMS 2003-001. Anchorage, AK: USDOI, MMS, Alaska OCS Region

USDOI, MMS, Pacific OCS Region. 2001. Delineation Drilling Activities in Federal Waters Offshore Santa Barbara County, California. Draft EIS OCS EIS/EA, MMS 2001-046. 7. Camarillo, CA: USDOI, MMS, Pacific OCS Region.

Vincent, W.F., J.A.E. Gibson, and M.O. Jeffries. 2001. Ice-Shelf Collapse, Climate Change, and Habitat Loss in the Canadian high Arctic. Polar Record 37(201):133-142.

von Ziegesar, O., E. Miller, and M.E. Dahlheim., 1994. Impacts on Humpback Whales in Prince William Sound.

In: Marine Mammals and the Exxon Valdez, T.R. Loughlin, ed. San Diego, CA: Academic Press, Inc., pp.

173-191.

Wainwright, P. 2002. GIS Geospatial Database of Oil-Industry and Other Human Activity (1979-1999) in the Alaskan Beaufort Sea. Volume 1. OCS Study, MMS 2002-071. Anchorage, AK: USDOI, MMS, Alaska OCS Region.

Walsh J.E. 2003. Severe Weather in a Changing Arctic Climate. Abstract. In : 54 th Arctic Science Conference, Extreme Events Understanding perturbations to the Physical and Biological Environment, Fairbanks, Ak., Sept. 21-24, 2003. Fairbanks, AK: American Association for the Advancement of Science, p. 45.

Walsh, W.A., F.J. Scarpa, R.S. Brown, K.W. Ashcraft, V.A. Green, T.M. Holder, and R.A. Amoury. 1974.

Gasoline Immersion Burn. New England Journal of Medicine 29(1):830.

Waring, G.T., D.L. Palka, K.D. Mullin, J.H.W. Hain, L.J. Ha nsen, and K.D. Bisack. 1997. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments C 1996. NOAA Tech. Memo. NMFS-NE-114: 250 pp.

Ward, J.G. and G.E. Pessah. 1988. Industry Observations of Bowhead Wh ales in the Canadian Beaufort Sea,

1976-1985. In: Port and Ocean Engineering Under Arctic Conditions: Symposium on Noise and Marine Mammals, J.L. Imm and S.D. Treacy, eds. Fairba nks, AK: UAA Fairbanks, The Geophysical Institute, pp. 75-88.

Wartzok, D., W.A. Watkins, B. Wursig, and C.I. Malme. 1989. Movements and Behavior of Bowhead Whales in Response to Repeated Exposures to Noises Associated with Industrial Activities in the Beaufort Sea. Anchorage, AK: AMOCO Production Company.

Wartzok, D., W.A. Watkins, B. Wursig, R. Maiefski, K. Fr istrup, and B. Kelley. 1990. Radio Tracking Studies of

138the Behavior and Movements of Bowhead Whales in the Beaufort S ea, Fall 1988-1989. In: Fifth Conference on the Biolog y of the Bowhead Whale Balaena Mysticetus . Anchorage, AK: AMOCO Production Company.

Watkins WA, Moore KE, Sigurjonsson J, Wartzok D, Sciara GNd. 1984. Fin whale ( Balaenoptera physalus ) tracked by radio in the Irminger Sea. Rit Fiskideildar 8(1):1-14.

Watkins WA. 1981. Activities and underwater sounds of fin whales. Report of the International Whaling

Commission 33:83-117.

Watkins, W.A. 1986. Whale reactions to human activities. Mar. Mamm. Sci. 2:251 B 262.

Watkins WA, Tyack P, Moore KE, Bird JE. 1987. The 20-Hz signals of finback whales ( Balaenoptera physalus ). Journal of the Acoustical Society of America 82(6):1901-1912.

Whitehead H. 1982. Populations of humpback whales in th e northwest Atlantic. Report of the International Whaling

Commission 32:345-353.

Whitehead, P. J. P., 1985. King Herring: his place amongst the clupeoids. Can. J. Fish. Aqua. Sci. 42 (Suppl. 1):3-

20.

Wiley DN, Asmutis RA, Pitchford TD, Gannon DP. 1995. Stranding and mortality of humpback whales, Megaptera novaeangliae, in the mid-Atlantic and southeast United States, 1985-1992. Fishery Bulletin 93:196-205.

Williams, M.T. and R. Rodrigues. 2003. B P's Activities at Northstar, 1999-2002. Chapter 2. In : Monitoring of Industrial Sounds, Seals and Bowhea d Whales near BP’s Northstar Oil Development, Alaskan Beaufort Sea, 1999-2002, W.J. Richardson and M.T. Williams , eds. LGL Report TA270 7-5. Anchor age, AK: BPXA, Dept. of Health, Safety & Environment.

Winsor, P. 2001. Arctic Sea Ice Thickness Remained Constant during the 1990's. Geophysical Research Letters 28(6):1039-1041.

Woody, D.A. and D.B. Botkin., 1993. St ock Sizes Prior to Commercial Whaling. In: The Bowhead Whale , J.J. Burns, J.J. Montague, and C.J. Cowl es, eds. Special Publication of The Society for Marine Mammalogy, 2. Lawrence, KS: The Society for Marine Mammalogy, pp. 387-407.

Woshner, V.M., T.M. O'Hara, j.A. Eurell, M.A. Wallig, G. R. Bratton, R.S. Suydam, and V.R. Beasley. 2002. Distribution of Inorganic Mercury in Liver and Kidney of Beluga and Bowhead Whales through Autometallographic Development of Light Microscopic Tissue Sections. Toxicological Pathology

302:209-217.

Wursig, B., E.M. Dorsey, W.J. Richardson, and R.S. Wells . 1989. Feeding, Aerial and Play Behaviour of the Bowhead Whale, Balaena mysticetus , Summering in the Beaufort Sea. Aquatic Mammals 15(1):27-37.

Zeh, J.E. and A.E. Punt. 2004. Updated 1978-2001 A bundance Estimates and their Correlation for the BeringChukchi-Beaufort Sea Stock of Bowhead Whales. Unpulished Report SC/56/BRG1 submitted to the International Whaling Commission. Cambridge, UK: IWC, 10 pp.

Zeh, J.E., A.E. Raftery, and A.A. Schaffner. 1995. Revised Estimates of Bowhead Population Size and Rate of Increase. Report of the International Whaling Commission 46. SC/47/AS10. Cambridge, UK: IWC, pp.

670-696.

Zeh, J.E., C.W. Clark, J.C. George, D. Withrow, G.M. Carroll, and W.R. Koski. 1993. Current Population Size and Dynamics. In : The Bowhead Whale , J.J. Burns, J.J. Montague, an d C.J. Cowles, eds. Special Publication of the Society for Marine Mammalogy2. Lawrence, KS: The Society for Marine Mammalogy, pp. 409-489.

139140 Zeh, J.E., D. Poole, G. Miller, W.R. Koski, L. Baraff, and D. Rugh. 2002. Survival of Bowhead Whales, Balaena mysticetus, Estimated from 1981-1998 Photoidentification Data. Biometrics 58(4):832-840.

Zykov, M., D. Hannay, and M.R. Link. 2007. Underwater sound measurements of ambient and industrial sound levels near Oooguruk drillsite, Alaskan Beaufotr Sea, September 2006. Unpublished report prepated by JASCO Research, Ltd. And LGL Alaska Research Associated, Inc. for Pioneer Natural Resources, Alaska, Inc., Anchorage, AK. 35p.