Marine Policy 36 (2012) 454–462

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Marine Policy

0308-59

doi:10.1

n Corr

E-m1 Pr

Anchora

journal homepage: www.elsevier.com/locate/marpol

Implications of Arctic industrial growth and strategies to mitigate futurevessel and fishing gear impacts on bowhead whales

Randall Reeves a, Cheryl Rosa b,1, J.Craig George b, Gay Sheffield c, Michael Moore d,n

a Okapi Wildlife Associates, Hudson, Que., Canada J0P 1H0b Department of Wildlife Management, North Slope Borough, Barrow, AK 99723, USAc University of Alaska Fairbanks, Marine Advisory Program, Box 400, Nome, Alaska 99762, USAd Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA

a r t i c l e i n f o

Article history:

Received 30 June 2011

Received in revised form

8 August 2011

Accepted 9 August 2011Available online 17 September 2011

Keywords:

Bowhead whale

Right whale

Ice retreat

Arctic

Vessel strike

Fishing gear entanglement

7X/$ - see front matter & 2011 Elsevier Ltd.

016/j.marpol.2011.08.005

esponding author. Tel.: þ1 508 289 3228; fax

ail address: mmoore@whoi.edu (M. Moore).

esent address: U.S. Arctic Research Commiss

ge, AK 99501, USA.

a b s t r a c t

The objective of this paper was to investigate and illustrate how insights gained from experience

managing human activities in order to protect North Atlantic right whales (Eubalaena glacialis) along

the heavily industrialized east coast of North America might be applied in the Arctic, where bowhead

whales (Balaena mysticetus) face some of the same risks as right whales. The reduced extent and

thickness of sea ice and the resultant longer open-water season have major, complex implications for

the Arctic marine ecosystem. Increased maritime ship traffic and commercial fishing in the Arctic are

bound to affect bowheads and Native (indigenous) hunting communities who depend on whales for

subsistence and cultural identity. Bowheads and right whales were greatly depleted by commercial

whaling in the 19th and early 20th centuries. While the Western Arctic bowhead population has been

recovering steadily in recent decades, North Atlantic right whales remain highly endangered because of

persistent lethal and sublethal vessel strikes and frequent entanglement in commercial fishing gear.

Entanglement can be transitory or persistent, with debilitation lasting for months before the animal

finally succumbs. Vessel strike and fishing gear trauma has been documented in bowheads, but at a

much lower rate than in right whales. Initiatives intended to mitigate the impacts of ship traffic on

North Atlantic right whales have included speed limits and routing changes. Those meant to reduce the

incidence and severity of entanglements include the modification of gear design and gear deployment

practices. Management measures need to be considered in advance in the Arctic in order to minimize

the risks to bowhead whales as shipping and industrial fishing expand in the Arctic with ice retreat.

& 2011 Elsevier Ltd. All rights reserved.

1. Introduction

In the Arctic there is open water where there used to be seaice. Climate change is leading to greater integration of the Arcticwith the global economy by reducing sea ice and lengthening theopen-water season [1,2]. This integration is occurring primarilythrough development of the region’s vast natural resources thatwere previously out of reach or uneconomic to exploit. The BeringStrait is the only maritime transportation corridor between theArctic and Pacific oceans (Fig. 1). Shipping to and from Arcticdestinations will continue expanding with the heightened inter-est in viable shipping routes, such as the Northwest Passage(Canadian Arctic) and Northern Sea Route (Russian Arctic).Offshore oil and gas development has been underway in the

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Arctic for several decades and is expected to expand with milderclimate conditions and rising energy prices. Resultant industria-lized vessel traffic and more intensive use of certain types ofcommercial fishing gear will increase the risk of harm to bowheadwhales (Balaena mysticetus) and other living resources critical tosubsistence communities in the Arctic.

The susceptibility of bowhead whales to lethal ship strikes andto entanglement in fishing gear is demonstrated by two types ofevidence: one direct and the other by analogy. About one or twopercent of the whales taken in recent years by Alaska Nativesubsistence hunters had wounds or scars consistent with shipstrike and approximately 10% bore evidence of entanglement[3,4]. In addition, bowheads with commercial crab-pot linesfouling their baleen or wrapped around their caudal pedunclehave been taken or found stranded in Alaska [5] or floating in theRussian Sea of Okhotsk [6]. A bowhead whale was recently foundfloating dead in Kotzebue Sound (Alaska) entangled in intactcommercial pot gear (Fig. 2), the gear being the likely the cause ofdeath.

Fig. 1. Map of places mentioned in the text, and of whaling villages in Alaska and Chukotka.

R. Reeves et al. / Marine Policy 36 (2012) 454–462 455

Indirect evidence that large vessels and various kinds of fishinggear are hazardous for bowheads is derived from studies on theirnear relatives, North Atlantic right whales (Eubalaena glacialis) [7,8].The Western Arctic (Bering, Chukchi, and Beaufort seas, or BCB)population of bowheads and several populations of southern rightwhales (Eubalaena australis) have been increasing steadily overseveral decades in relatively non-industrialized environments[9,10]. In contrast, right whales located in the heavily industrializedwaters off eastern North America have been recovering more slowlysince the cessation of commercial whaling on them in 1935.Recovery of the right whale population from commercial whalinghas been slow due to the mortality and serious injuries caused byship strikes and gear entanglement [11]. Thus, by analogy, there iscause for concern about the future of bowhead whale populations ina rapidly changing Arctic where volumes of industrial vessel trafficand commercial fishing gear are expected to increase.

This paper highlights certain issues in an anticipatory andproactive manner, with the goal of ensuring that bowhead whales(and other marine mammals) will be safeguarded to preserveArctic biodiversity and allow continued resource use by Arcticcommunities. Considering that rapid and dramatic change isalready underway across the Arctic, timely action is essentialand it will be important to take full advantage of lessons learnedin other areas where similar human activities and animals havecome into conflict. To that end, a workshop was convened in July2009 that brought together subsistence hunters from northernAlaska, researchers who had worked with bowhead whales in theArctic and right whales in the North Atlantic, and Alaska marinemanagers with responsibility for environmental protection(see supplemental online material for workshop abstracts). Theobjectives of the workshop were to explore how information fromthe industrialized North Atlantic has been used to mitigate theadverse effects of large vessel traffic and commercial fishingactivity on right whales and to consider how that informationmight be used in the Alaskan Arctic to prepare for increasedindustrial vessel traffic and commercial fishing activity there.

Two caveats apply to the scope of this paper. First, the Arctic,as used here, is defined by the range of bowhead whales. Their

circumpolar range extended historically all the way south to theStrait of Belle Isle and the Gulf of St. Lawrence in the Atlantic [12],and their present-day winter range in the Pacific includes much ofthe central and northwestern Bering Sea [13]. Also, part of thebowhead population in the Sea of Okhotsk summers near theShantar Islands at latitudes of approximately 551N [14]. Our useof the term Arctic refers to northern areas with seasonal sea-icecoverage and our focus is specifically on the Alaskan Arctic.

The second caveat is that other factors associated withindustrialization of the Arctic will also pose risks to bowheadwhales and to coastal communities who hunt them. Not the leastof these is underwater noise from seismic surveys, drilling opera-tions, and ship and barge traffic. Noise from offshore oil and gasactivity has been shown to deflect the whales away from huntingareas and thereby reduce the success rate of subsistence hunters[15]. Additionally, acoustic deflection likely has energetic costs tothe animals and it may affect them in ways yet to be determined.Until recently, the Arctic has functioned as a kind of acousticrefuge, wherein the underwater environment was relatively freeof industrial noise [16]. The inevitable masking and disturbancefrom manmade underwater sounds could be the greatest long-term threat to the Arctic’s biological richness, and the noise issueas it relates to bowhead whales must be addressed. Additionally,contamination, or perceived contamination, of bowheads andother marine resources by petroleum products and other toxi-cants is a serious food-safety concern for coastal subsistencecommunities [17]. A brief final section of this paper considershow these and other important issues could prove to be just asimportant as, or even more important than, ship strikes andentanglement for the future of bowhead whales.

2. Bowhead whales and right whales compared

2.1. General features

Bowhead whales have a circumpolar Arctic distribution, withthe largest population currently found in the BCB seas, estimated

Fig. 2. An entangled bowhead whale. (a) Adult female (10KTZ-FD1) found floating

dead and entangled in commercial pot gear in the southern Chukchi Sea in

Kotzebue Sound near Cape Espenberg during July 2010. Skin and blubber removed

from left lateral ventrum area. (b) Pot gear with webbing, rope bridle, and

approximately 36 m of 19 mm diameter rope removed from the dead bowhead.

30 cm wooden ruler beside metal bar for scale. Images by John Larsen and Gay

Sheffield.

2 In their book The Urban Whale: North Atlantic Right Whales at the Crossroads,

Kraus and Rolland (2007, p. 33) describe this right whale population’s environ-

ment as follows: ‘‘Humans have collectively created an urban ocean zone into

which the byproducts of our civilization have been imported. It has all the smells,

tastes, and sounds of a busy city street, and for the naıve animal or person

traveling in such a place, it poses some risks as well.’’

R. Reeves et al. / Marine Policy 36 (2012) 454–462456

at 10,470 in 2001, and 12,631 (CV¼0.244) in 2004, consistentwith an annual rate of increase of 3.4% [9]. There are alsothousands of bowheads in the Eastern Canada–West Greenlandpopulation and it too is growing [18]. The once very largeSvalbard–Barents Sea population and the relatively small Sea ofOkhotsk population are thought to remain at remnant levels withno clear evidence of recovery from severe depletion by commer-cial whaling [14,19]. The strong recovery of bowheads in theWestern Arctic can be attributed to low anthropogenic mortalityand a relatively pristine habitat. Subsistence hunting is wellmanaged and sustainable at current levels of take [9].

The North Atlantic right whale is one of the most endangeredwhale species in the world. The population in the western NorthAtlantic (the species is virtually extinct elsewhere in its historicrange) is small, estimated to number 400–450 in 2010 [20], and is‘‘transboundary’’, migrating between the southeastern coast ofFlorida (USA) and the Gulf of St. Lawrence (Canada) with at leastoccasional excursions of a few individuals to waters off southernGreenland, Iceland, and Norway. The primary range is intersected byareas of concentrated maritime industrial activity. Human-induced

traumas to North Atlantic right whales fall into three categories:sharp propeller incisions, blunt vessel impacts, and constrictivelacerations by fishing gear [8]. Databases and source files on casesof persistent entanglement, photo-identification of previouslyentangled or vessel-struck whales, and necropsy reports are avail-able to interested parties through the North Atlantic Right WhaleConsortium (narwc.org).

2.2. Similarities

Right whales and bowhead whales are related through theirevolutionary history and have similarities in morphology, behavior,feeding, reproduction, and migration strategies. Both are long-lived(probably 4100 years) members of the mysticete family Balaeni-dae, and hence they are more closely related genetically to eachother than to other baleen whales. They lack expansible throatregions, have long baleen plates, are well endowed with blubber,and have large tail flukes and paddle-shaped flippers. Theytypically feed by pushing their open mouth through dense plank-ton aggregations for protracted periods, either at the surface or atdepth. They aggregate periodically in groups of tens of animals forintense social interactions that often include body contact andcopulation. The gestation period spans 12–13 months. Their verylarge testes likely reflect sperm competition. Adult females calveevery three or four years, or at longer intervals at times, possiblydue to reduced food abundance and/or quality [21].

Bowheads and right whales generally migrate to higherlatitudes in the summer, although the pattern for bowheads iscomplex and can involve longitudinal movements in the summer,depending on local or regional sea ice conditions and possiblyother factors such as patchiness of food resources and predationpressure. Both species pass close to shore at times, and theirfeeding areas are as likely to be near-shore as offshore [22].Migratory routes and sites of aggregation that coincide withcoastal shipping routes as well as commercial fishing areas, andtheir slow reproductive rate are among the attributes that putboth bowheads and right whales at particularly high risk.

2.3. Differences

There are many differences in the circumstances under whichthe BCB bowhead population and the North Atlantic right whalepopulation exist today. Among the most obvious is that thebowheads inhabit a relatively pristine environment while theright whales inhabit an increasingly urban environment charac-terized by concentrations of large ocean-going vessels and avariety of commercial fishing gear.2

In northern and western Alaska, there is widespread subsistenceuse of marine mammals (Fig. 1), whereas along the east coast of theUnited States, marine mammals are fully protected from hunting.The Alaskan subsistence hunt for bowheads in northern and westernAlaska provides an exceptional opportunity for scientific examina-tion (‘‘necropsy’’) of whales each year. Predictable, orderly, andproductive data and samples are collected annually through colla-boration between subsistence users and scientists. This allowsinvestigations of bowhead whale anatomy, physiology, life history,and health to occur in a consistent manner, at least in the larger,more accessible communities. However, the logistics of hunting and

Fig. 3. White entanglement scars on the peduncle of a subsistence harvested

bowhead whale 03B8. A webbing strap conceals the fluke insertions to the left.

Image by Craig George.

R. Reeves et al. / Marine Policy 36 (2012) 454–462 457

travel mean not all harvested bowheads in Alaska are given acomplete postmortem examination.

In contrast, fresh right whale carcasses are a rarity on the eastcoast of North America, and researchers are typically faced withvariably decomposed remains of animals that have died fromuncertain causes. Access is dictated by the unpredictable locationand timing of discovery, and the logistical challenges of gettingappropriate people and equipment to a carcass can be formidable.Necropsies of right whales frequently become exercises in foren-sics, with determination of the cause of death a paramount aim.Significant, diagnostic trauma related to a large vessel strike orfishing gear entanglement is often observed, which along with theindividual right whale’s prior sighting history can often allow areasonable inference as to how and why the animal died [8].

Ready access to scientific supplies and equipment, transporta-tion options, and typically non-freezing conditions are advantagesto researchers performing necropsies on temperate-region rightwhales. Population surveys in small boats and light aircraft arefeasible and relatively safe and inexpensive in areas where NorthAtlantic right whales are studied intensively (e.g. Bay of Fundy,Cape Cod Bay, Great South Channel, and near-shore waters ofGeorgia and northern Florida). In contrast, population surveys ofbowhead whales in the Arctic require larger vessels, longer-rangeaircraft, and arrangements for obtaining fuel and provisions inremote locations as there is no road access to the northern andwestern coasts of Alaska. Ironically, the small size of the NorthAtlantic right whale population is a great advantage when itcomes to research on the living population. Detailed demographicinformation (sex, age, and pedigree) is available on a largeproportion of the individuals; most have been photo-identifiedrepeatedly and ‘‘biopsied’’ at least once (i.e., darted with a cross-bow to obtain a small piece of skin). It is relatively easy to censusthe right whale population and to follow the individual lives of itsmembers. The BCB bowhead population, on the other hand, islarger, more wide-ranging, and inhabits a remote region with aless populated and industrialized coast.

3. Vessel strikes

3.1. What is known and what is predicted for the Alaskan Arctic

Although there are uncertainties regarding the geography,scale, and rate of change of vessel activity in the Arctic, so-called‘‘destinational’’ ship traffic (i.e. vessels that are headed to or froman Arctic port, as opposed to those that are transiting throughthe Arctic from one non-Arctic port to another) is increasing.According to the U.S. Coast Guard, in 2010, 17 ships traversed theNorthwest Passage for adventure travel, an increase from 12 shipsin 2009. Dockings at the Port of Nome increased from roughly 34in 1990 to 301 in 2009. Growing fleets of large, ice-reinforcedbulk carriers transport hydrocarbon products (e.g. oil, liquefiedgas, and coal) and hard minerals (mainly lead and zinc) fromsources in the Arctic to southern processing sites and markets. In2010 a passenger ferry (September) and an offshore icebreakingvessel (December), both escorted by a nuclear icebreaker, as wellas a 305 m (1000 ft) ship carrying 70,000 tons of gas condensate,traveled through the Bering Strait going to and from the NorthernSea Route. Russian authorities expected another half-dozen ofthese vessels and a larger number of ships carrying industrialsupplies to travel a similar route in 2011 (USCG Rear AdmiralChristopher Colvin, Spotlight on Canada–US Collaboration Work-shop, Feb. 2011). Additionally, cruise, military, and researchvessels as well as support vessels for resource extraction effortsare becoming familiar sights in many northern communities.

Data were compiled from postmortem examinations of 459bowheads landed as part of the subsistence hunts at Barrow andKaktovik, AK, over the period 1988 through 2007. Biologistsexamined �90% of the landed whales for scarring and otherbiological parameters at these two villages. Preliminary analysesindicate that �10% (41 certain, 7 possible; n¼48) of the whalesbore scarring consistent with line-inflicted wounds (Fig. 3) and2–3% (9 certain, 4 possible; n¼13) with ship or propeller injuries.As not all harvested whales were fully examined, these estimatesmay be biased downwards. During the same period, at least twolanded whales and five dead stranded whales had pot-fishing gearattached. A detailed analysis of these data is underway forpublication by JCG and GS.

3.2. How vessel strikes have been documented and addressed for

North Atlantic right whales

Vessel strikes are the most significant known cause of mortal-ity of North Atlantic right whales [23]. In fact, vessel strikes havecome to be viewed as a globally significant mortality factor forlarge whales generally, and the available records indicate thatNorth Atlantic right whales experience the highest per capita rateof vessel strikes of any species of large whale worldwide [24,25].A robust program to mitigate this problem requires quantitativeestimates of vessel strikes, how strike rates change over time,where strikes are most likely to occur, and the options availablefor minimizing strike probabilities [26].

Vessel strikes are usually peracute if they are fatal. Non-fatalstrikes lead to healed scars that may persist for years. Of 77 rightwhale deaths recorded between 1970 and 2007, necropsies wereperformed on 45 carcasses, and vessel strike was identified as thecause of death in 24 of those cases ([8] and unpublished data byMoore). Of the vessel strike-related mortality, the cause of deathin 15 (56%) of the cases was acute sharp trauma, while 9 (20%) ofthe deaths were attributed to blunt trauma. Cuts in the upper backand head were more likely to be lethal than cuts in the caudal partof the body, although lethal cuts were observed in all bodyregions. External evidence was absent in 44% (4/9) of the blunttrauma cases. Thus, the true extent of non-lethal blunt trauma isnot known. Skeletal fractures were observed in most (8/9 or 89%)of the lethal blunt trauma cases, and a broken mandible wasobserved in a third (3/9) of all lethal blunt trauma cases examinedby necropsy [27]. Modeling of the biomechanics of right whale

R. Reeves et al. / Marine Policy 36 (2012) 454–462458

tissues is being applied to determine the vessel speed and sizecombinations capable of fracturing a right whale mandible [28].

A reduction in mortality from vessel strikes is an essentialelement of North Atlantic right whale recovery efforts [29,30].Annually, 60–70% of the cataloged population3 feeds and socializesin Canadian waters during the period from May through October,principally in two regions designated as Critical Habitat under theCanadian Species at Risk Act: the Grand Manan Basin region of thelower Bay of Fundy and the Roseway Basin region of the south-western Scotian Shelf. Five deaths from vessel strikes have beendocumented in these areas since 1992, demonstrating that overlapbetween high concentrations of right whales and high concentra-tions of vessels associated with the mandatory Traffic SeparationScheme (TSS) in the Bay of Fundy and the habitual traffic patternsacross Roseway Basin is a serious risk factor.

A vessel-strike risk analysis of the spatial distribution of vesselsand whales was the basis for two policy actions in Canada, bothdesigned specifically to minimize the risk of lethal strikes to rightwhales without unduly compromising vessel navigation and safety[31]. A working group, led by scientists and including representa-tives of various maritime interests and government agencies,proposed navigational alternatives with the goal of reducing therisk of vessel strikes in the two regions where right whalesaggregate seasonally. The chosen alternatives were then advocatedby officials of the Canadian government and eventually adopted bythe International Maritime Organization (IMO). In the Bay ofFundy, the mandatory TSS was shifted eastward and reconfiguredin 2003 to route vessels around the right whale high-use area,thereby reducing the risk of lethal vessel strikes by 90% [32]. InRoseway Basin, an Area To Be Avoided (ATBA) was adopted in2008, reducing the risk of lethal vessel strikes there by anestimated 82% [33]. Voluntary compliance in this ATBA is beingmonitored through the non-governmental Vessel Avoidance ofConservation Area Transit Experiment via land-based monitoringof Automatic Identification System (AIS) transponders, which aremandatory on vessels greater than 19.8 m length. AIS enablesvessel speed, location, and movement data to be compared beforeand after introduction of vessel management measures. Shipperswho comply are congratulated and encouraged by direct commu-nications from scientists to the vessel operators, mediated throughthe Marine Stewardship Recognition Program (Pers. Comm.M. Brown, Canadian Whale Institute, P.O. Box 410, Wilson’s Beach,New Brunswick, Canada E5E 1Y2). These two steps of reroutingvessels to protect whales in Canadian waters, both sanctioned bythe IMO, set a precedent for national and international marineconservation policy. They provide individual vessel operators andthe shipping industry as a whole with credible, direct-action meansof contributing to the conservation of right whales.

It is widely realized that ‘‘reducing the co-occurrence ofwhales and vessels is likely the only sure means of reducing shipstrikes’’ [34]. However, in situations where the conflict betweenwhales and vessels cannot be mitigated by changing vesselmovement patterns, an alternative strategy is to slow vesselsdown to a speed that reduces the lethality of collisions. Thegreatest rate of change in the probability of a lethal injury to alarge whale occurs at vessel speeds of between 8.6 and 15 knots,in which interval that probability increases from 0.21 to 0.79 [25].The probability of a lethal injury drops below 0.5 at a vessel speedof 11.8 knots. At speeds above 15 knots, the probability asympto-tically approaches 1.

There have been 23 known deaths of right whales from vesselstrikes since 1986, and efforts have been made since the 1990s to

3 Meaning individuals included in the photo-identification catalog maintained

by the New England Aquarium, Boston, MA, USA.

reduce the incidence of these events in three areas of legallydefined ‘‘critical habitat’’ (southeastern US calving ground, CapeCod Bay, and Great South Channel) and in the migratory corridorsconnecting them. In 1999, the IMO adopted a Mandatory ShipReporting System in the northeastern and southeastern US. In2006, NOAA implemented a voluntary routing system to mini-mize transit distances by ships crossing the southeastern UScalving ground and Cape Cod Bay en route to and from port. By2007, the IMO had adopted an amendment to the Boston TSS,rerouting traffic around high concentrations of right whales andhumpback whales (Megaptera novaeangliae) and into an area withlower whale concentrations. In 2008, NOAA implemented regula-tions limiting the speed of all vessels 65 ft (19.8 m) or longer to nomore than 10 knots when within 20 nm of port entrances at alltimes of the year and when inside critical habitat areas on aseasonal basis. Those regulations also include a provision fordynamic management areas to be implemented in response toephemeral aggregations of three or more right whales. Mostrecently the IMO adopted a Great South Channel ATBA [35] anda narrowing of the Boston TSS [36].

The record of vessel strike documentation and mitigation onthe Atlantic coast demonstrates that it is possible to developeffective, science-driven policy tools for conservation, make theseavailable in practical form, and see them fully implemented bythe relevant agencies. Science also provides quantitative means tomeasure policy efficacy through (a) monitoring vessel compliancein near to real-time, (b) direct communications with vesselowners, (c) documentation of frequency and severity of vesselstrikes, and (d) analysis of anecdotal close-call or strike reports[37]. In some cases, compliance is enhanced through near real-time communications regarding whale locations as determinedthrough passive acoustics or visual surveys in high-risk areas [38].

3.3. Recommended next steps and things to consider

Based on the current and forecasted Arctic vessel activity andon the successful, if limited, experience with mitigating the shipstrike risk to right whales in the North Atlantic, the followingconclusions can be drawn:

�

Government agencies, industries, and communities in theArctic should continue to accord high priority to the comple-tion of the AIS receiver network there. AIS ship traffic datacould be compared to known bowhead whale migrationroutes, and areas of potentially high risk of vessel strikes couldbe identified. � As a chokepoint and funnel through which virtually the entire

BCB bowhead population migrates each spring and autumn,the Bering Strait should be given special consideration. Forexample, satellite tagging has provided clear evidence of largeautumn aggregations of bowheads along the Chukotka coastjust northwest of the Bering Strait [39], in areas on or adjacentto Northeast Passage shipping lanes. A vessel traffic monitor-ing system should be established in the strait, along with avessel-strike risk analysis of the spatial and temporal distribu-tion of vessels and whales in the region. This would providethe basis for a regional vessel separation and tracking systemthat, once published by the Federal government as a proposedrule, would trigger the preparation of an EnvironmentalImpact Statement and an Endangered Species Act Section7 consultation. During such a consultation, all viewpoints,including particularly those of whale hunting communities,would be considered. The resultant Biological Opinion andReasonable and Prudent Alternatives could then specify mea-sures to address the concerns raised. These might includeseasonal ‘‘bowhead corridors’’ in which vessels are prohibited,

R. Reeves et al. / Marine Policy 36 (2012) 454–462 459

other kinds of vessel routing that would preclude mostpotential conflicts between bowheads and vessels, vesselspeed restrictions in certain areas or seasons, a network ofexperts prepared to investigate reported incidents, mandatoryVMS, or expanded AIS throughout western and northernAlaska. Additional consideration is needed, especially in theBering Strait region, to minimize interactions between largevessels and subsistence community members traveling and/orhunting in small boats (e.g. provision of VHF radios).

Separating industrial maritime traffic and large whales isalways the preferred mitigation option, but where infeasible,the best option is to restrict large vessel speeds, to the extentthat safety considerations allow, given local currents, depth, andweather, as this will reduce the frequency and severity of vesselstrikes. An excellent and effective example is the time/spaceseparation scheme of industry vessels, seismic operations, andwhale hunting activities in the US Beaufort Sea set forth in theAlaska Eskimo Whaling Commission’s ‘‘Conflict Avoidance Agree-ment’’ with industry [40].

�

It is essential to involve industrial maritime representatives indiscussions of vessel strike mitigation measures. In Alaska, itwill be particularly important to engage ‘‘destinational’’ opera-tors, including the cruise ship industry. The ATBA study in theRoseway Basin region [33] shows that vessel operators can andwill avoid regions, especially if mandated by the IMO. � Extension of compulsory pilotage to encompass the entire

Exclusive Economic Zone in the Arctic is another option.Although many operators and managers may judge suchextension to be inadequately justified and unnecessarily bur-densome, at least a selective extension to cover specific areasmay be warranted given the exceptional character of theregion’s resources in combination with the scale and complex-ity of navigational hazards.

4. Entanglement in fishing gear

Incidental mortality (bycatch) in fishing gear is recognized as amajor threat to cetaceans worldwide, and this has been true forseveral decades [41–43]. To date, bowhead whales and otherpolar species have been largely spared from frequent entangle-ment because the intensity of commercial fishing in polar waters(but not necessarily the Bering Sea where most BCB bowheadsoverwinter) has been relatively low.

4.1. What is known and what is predicted for the Alaskan Arctic

Already by the early 1990s, it was recognized that expandingcommercial fishing effort for crabs, particularly Tanner crabs(Chionoecetes spp., primarily Chionoecetes opilio, which are alsoknown as opilio or snow crabs), in the Bering Sea was likely toresult in occasional entanglements of bowhead whales [45]. Likethe fisheries using fixed gear off the North American east coast,which are most responsible for entanglements of right whales andhumpback whales there [39], the crab fishery on the Bering Seashelf involves pots that are most commonly 2.1�2.1�0.8 m,weigh about 318 kg, with buoy lines normally about 122 m, thoughline length varies with water depth [44]. (The black cod Anoplo-

poma fimbria and king crab Paralithodes spp. fisheries also use potsin areas used by bowheads in the Bering Sea.) The US commercialcrab fishery has changed a great deal since the 1980s, when it wasat its maximum. The current fleet is smaller, vessels tend to fish forlonger periods in productive areas, and there is less of a tendencyfor vessels to push far into the pack ice. Although satellite-tag

locations indicate that some BCB bowheads concentrate northwestof the contemporary crab-fishing grounds, entanglement remains arisk as shown by the recent incident in Kotzebue Sound mentionedearlier. As Burns [45] described, ‘‘Bowheads are most likely tangledwhen southward advancing sea ice overruns the fishing grounds;a common occurrence in some areas. In such circumstances thewhales move into the fishing areas and apparently occasionallybecome entangled in the lines’’.

In 2009, the North Pacific Fisheries Management Council closedthe Arctic Management Area (federal waters in the US Arctic) tocommercial fishing. This area will be closed until data (largelyabsent at present) improve so that fishing can be conductedsustainably and with due concern for other ecosystem components.Commercial fishing is permitted south of the Bering Strait wherebowheads are resident for �5 months of the year. This may helpexplain why close to 10% of the bowhead whales landed by theAlaskan whale hunters in recent years show entanglement scarring.

4.2. How has this threat been documented and addressed for North

Atlantic right whales

Entanglements of North Atlantic right whales in commercialfishing gear have been recognized since the 1970s [46] but havebeen the subject of intensive study only since the early 1990s [7].At present, more than 70% of the right whales observed offeastern North America carry scars or wounds from encounterswith commercial fishing gear [47]. The annual entanglement rateis about 15%, i.e. an estimated 50 new encounters between rightwhales and fishing gear each year. The minimum annual rate ofmortality from entanglement is �0.8 [48], although some scien-tists suspect this is an underestimate given the rate at whichphoto-identified individuals ‘‘disappear’’ from the population (i.e.,more than 6 years pass with no photo-documentation of theliving animal) [11]. Since 1996, the National Marine FisheriesService has attempted to mitigate the problem of large whaleentanglement on the east coast through the Atlantic Large WhaleTake Reduction Team (ALWTRT). Mitigation includes compul-sory use of weak links at the buoy and in net panels as well asseasonal and regional use of sinking groundlines by the gillnetand pot fisheries. Suggestions have been made that gear shouldbe marked so that entangling gear can be traced to its source.A variety of alternative ropes, time-release line cutters, andacoustic and galvanic releases of bottom-stored retrieval lineshave been considered [49]. A particular drawback has been thelimited ability to evaluate the efficacy of proposed gear modifica-tions before they are added to fishery regulations, resulting insubstantial costs to the industry with no evidence of significantlyimproved mitigation [50]. Presently, the ALWTRT is focusing onresearch to reduce risks from vertical lines and assessment of theeffectiveness of the Take Reduction Plan.

An analysis of the incidence of fishing gear entanglement scarsand wounds did not show any clear evidence of a decreasingtrend [47], which reinforces the conclusion of an expert panel onNorth Atlantic right whales in 2007 [51, p. 51] that ‘‘the takereduction process has been neither efficient nor cost-effectivein reducing or eliminating the entanglement of right whales infishing gear’’. In a workshop at the New England Aquarium in2008, marine mammal scientists concluded that there was noway, at present, or in the foreseeable future, to make vertical linessafe for right whales [52].

Entanglement is often not fatal and whales manage to extricatethemselves from enough of the gear to swim free. However, whalesmay remain entangled for many years carrying large pieces ofnetting or rope, or even towing buoys. Some entanglements areresolved by human intervention, but others lead to chronic debili-tation and death [53] after an average of 5 months [54].

R. Reeves et al. / Marine Policy 36 (2012) 454–462460

There is a coast-wide disentanglement network in the easternUnited States and the Canadian Maritimes. However, networkresponses to badly entangled right whales are successful onlyabout half of the time, and they are very expensive.

From 1970 to July 2007, 47 cases of entanglement and 15entanglement-related deaths were documented involving indivi-dual right whales known from photo-documentation. Six percentof the whales involved in entanglements, but not confirmed dead,are presumed dead since they have not been photo-identified forsix or more years. When entanglements constrict the body, and/orwhen they involve more than one body part such as the head,flipper, or peduncle, the gear can cut through the flesh until aresistant body part is encountered, often bone. The result isa massive periosteal proliferation (the wrapping of the bone bya dense mass of new bone and fibrous tissue). In growing animals,flipper bones can grow notches around encircling rope. Modelingof rope–skin interaction demonstrates that cutting-in occurswhen the excursion of the rope exceeds the compliance of theunderlying tissue [55].

4.3. Recommended next steps and things to consider

Lessons learned from the management and mitigation measuresdeveloped for right whales in the North Atlantic can and should beapplied to bowhead whales in the Arctic. Very little is currentlyknown about the risk of entanglement to bowheads. Entanglementcertainly occurs, but it is not yet possible to point to any onefishery, or even to a single class of fisheries, as being of greatestconcern. Thus systematic documentation of the contemporaryspatial and temporal coincidence between bowheads and fishinggear is needed so that future threats can be anticipated. In Alaska,as everywhere, the fisheries and their management are constantlychanging (e.g. seasons, areas, species, amount and type of gear,etc.). Further, little is known about the mechanics of a fishing gearentanglement, how it occurs and how a whale frees itself onceentangled. Predictions concerning the threat of entanglement aretherefore a major challenge. For example, despite efforts over thelast 15 years to collect fishing gear from the bodies of NorthAtlantic right whales, alive or dead, and trace that gear to aparticular location or fishery, the entanglement problem continuesto be poorly understood and it remains impossible to know withcertainty whether mitigation efforts have been at all effective [56].

Based on contemporary and future commercial fishing activityin the Arctic and on the entanglements of right whales in theNorth Atlantic, the following conclusions can be drawn:

�

Bowheads are essentially right whales (without callosities onthe head) inhabiting an environment that is mostly gear-freeat present. If commercial fixed-gear fishing associated withextensive amounts of rope in the water column increases inbowhead habitat, entanglements will also increase and moredeaths will occur. Given the relatively few whale surveysconducted in the ice-free months, entanglements will bedetected only rarely and the problem is exacerbated by thenature of the western and northern Alaska coastline thatmakes systematic shoreline surveys impractical. Therefore,documentation of entanglements will continue to depend onthe examination of harvested animals or on the opportunisticdiscovery of carcasses. � Entanglement rate is a function of the concentrations and

coincidence of whales and fixed fishing gear. Mortality rate is afunction of entanglement severity and the nature of the gear(weight of gear, strength of ropes and lines, etc.). Area-specificmanagement is unlikely to be effective in decreasing the risk ofentanglement of bowhead whales for two reasons. First, thewhales are highly mobile and range across broad expanses of

ocean. Second, their distribution will probably expand inresponse to receding sea ice and the associated emergence of‘‘new’’ feeding habitat. While some level of entanglement isunavoidable, the aim should be to decrease the incidence to aslow a level as possible. Proactive mitigation of high-risk fishingscenarios requires funding and initiatives focussed onincreased monitoring and research that will identify andhasten the research on and development of low-risk fishinggear and practices.

� Lines in the water column represent a well documented and

measurable risk of lethal whale entanglements. For this andthe myriad reasons detailed above, the contemporary ban ondevelopment of commercial fisheries in the Alaskan Arctic,north from the Bering Strait, is visionary and proactive and it isessential that the ban be maintained until the stringentstipulations specified in the announcement of the ban by theNorth Pacific Fisheries Management Council are met. Animportant caution is that experimental fisheries, with rela-tively few restrictions, represent a mechanism for circumvent-ing the stipulations that were designed to maintain theecological integrity of the Arctic ecosystem. The developmentand adoption of practical, economically viable, and sustainablefishing practices that minimize the entangling-gear threat towhales should be a prerequisite for all commercial fisheries inthe Arctic. To this end, research with meaningful involvementof the fishing industry is essential and should be supported.

� The existing moratorium on the establishment of new com-

mercial fisheries in the Alaskan Arctic offers greater opportu-nity than was ever possible in the Atlantic for whale (and othermarine mammal) biologists and conservationists to develop apositive and functional working relationship with the industry.It will be important to avoid the pitfalls of the Take ReductionTeam approach that have plagued efforts to address theentanglement problem in the western North Atlantic.

� Determining the origin of fishing gear found on dead whales

(whether harvested for subsistence or found dead) must be apriority, not for the purpose of assigning blame but as a way ofobtaining essential information that will advance mitigation.An inventory of derelict gear found in the Arctic, with originsdetermined as accurately as possible, is a relatively straight-forward way to begin.

� There is considerable coincidence between bowhead whales

and commercial crab gear (and potentially black cod pot gear)in the Bering Sea, but almost nothing is known in detail aboutthis overlap. Therefore, a collaborative study that involveswhale researchers and individuals in the crabbing/fishingindustry is essential. The primary goals would be to investigate(a) the forensics of scarring and gear found or observed onbowhead whales and (b) the spatial and temporal coincidencebetween fishing activity and bowhead distribution. Satellitewhale-tagging data, survey data, expanded harvest monitor-ing, and fishery records should provide relevant insights.

� Entanglement is a multilateral and not just a national or

Alaskan problem. Regardless of the ban on new commercialfisheries in the Alaskan Arctic north of the Bering Strait,whales from the BCB stock migrate annually into the BeringSea, where they are at risk of encountering gear from bothAmerican and non-American fishing fleets.

5. Additional concerns

5.1. Noise

As mentioned in Section 1, underwater noise and its effects oncetaceans have become a major, global concern. Disturbance of

R. Reeves et al. / Marine Policy 36 (2012) 454–462 461

bowhead whales by noise from vessels, seismic prospecting, anddrilling operations has been a point of contention between theAlaskan Eskimo whale hunters and the oil industry in northernAlaska for over 25 years. It is a complex issue that is bound toescalate and expand as industrial, military, and recreationalactivities increase in the Arctic with receding sea ice.

5.2. Oil spills

The 2009 Arctic Marine Shipping Assessment report (AMSA2009) states, ‘‘the most significant threat from ships to the Arcticmarine environment is the release of oil through accidental orillegal discharge’’. The discharges of concern include both rawcrude oil and refined oil products. Bowhead whales presumablywould be particularly vulnerable to spilled oil as they migratethrough, and calve in, the spring lead system, which is oftenrestricted in size and complex in structure. There is considerabledisagreement between industry and non-industry experts onwhether current technology is adequate for recovering oil spilledin broken-ice conditions, but the balance of evidence clearlyindicates that there is much need for improvement in the abilityto both detect and recover oil spilled or trapped under sea ice inArctic and sub-Arctic waters. Recovery statistics for mechanicalresponse techniques are disappointing, and little progress hasbeen made toward developing additional technology. Improve-ments are also needed in addressing health and human safetyconcerns (e.g. getting response personnel safely to spill sites),operability of equipment in icy Arctic conditions, and rapidtransport of equipment (including leak control devices) fromheavily populated areas with manufacturing capability (e.g.Houston) to remote spill sites that would have exceptional andoften severe logistical considerations. Concerns surrounding theenvironmental effects of in situ burning, chemical dispersants, andherding agents remain. Although some data exist, much addi-tional research is needed in all of these areas, especially inrelation to metabolism and toxicity on Arctic biota. The in situ

testing of oil spill clean-up equipment and methods is critical forvalidation. Without opportunities to conduct experimental oilspills in relevant scenarios, it will remain difficult to evaluate thereliability of recovery techniques.

Two things must be borne in mind: (1) Given the unpredict-able, often intractable nature of oil spills, no amount of planningand preparation can eliminate the environmental risks of extract-ing and transporting oil in the marine environment, particularlyin the relatively harsh and remote conditions of the Arctic.(2) Therefore, the very highest priority for mitigation of the oilspill threat must always be prevention.

5.3. Other possibilities

Ballast water discharge and fouling of ships’ hulls can introducenon-native species, such as toxic algae, that have cascading, ecosystem-level effects [57,58]. The majority of ships discharging ballast water inAlaskan waters are from foreign ports and most of this ballast isuntreated [59]. At present, the risk of ship-mediated transfers ofinvasive species appears high and deserves additional research.

Another concern is that rapid changes in sea ice and otherocean conditions will allow species formerly scarce or absent inthe Arctic to expand their range northward. This is alreadyoccurring as humpback whales and gray whales (Eschrichtius

robustus) are now seen more frequently off Barrow in thesummer. Humpbacks, in particular, may compete with bowheadsfor euphausiid prey. In eastern Canada, killer whales havealready begun moving into areas from which they were formerlyexcluded by sea ice [60], giving them greater access to potentialprey such as bowhead whales. It is also possible, though perhaps

less likely, that newly arriving species from the south will exposebowhead populations to novel disease organisms, thereby heigh-tening the risk of disease-induced mortality or morbidity [61].

6. Conclusions

One way to begin to address many of the concerns highlightedin this paper would be through the expansion and strengtheningof stranding networks. A systematic program of detection, report-ing, and response, including rigorous necropsy protocols, isneeded to document whale deaths and their causes. This type ofeffort would allow temporal comparisons of stranding, injury, andentanglement rates. Federal resources are available to aid in thedevelopment of these networks.

It is essential to establish communication with local commu-nity and industry stakeholders well ahead of policy formulationand development so that concerns are fully considered in a timelyand ongoing manner. Also, the transboundary nature of thebowhead population makes it important that communicationand strategic planning are pursued on a bilateral, multilateral,or even international basis.

Although this paper has focused solely on the bowhead whaleas a bellwether species, numerous other marine mammal speciesin the Alaskan Arctic are ecologically significant and critical to thesubsistence of indigenous people. Such species (e.g. belugas, graywhales, walruses, polar bears, ringed, spotted, and bearded seals)deserve similar attention, and every effort should be made tomanage economic development in the Arctic in ways that pre-serve healthy, functional, and intact ecosystems.

Acknowledgments

The following workshop presenters provided thoughtful input:John Adams, Lawson Brigham, Harry Brower, Moira Brown, BenEllis, Dan Fitzgerald, Peter Garay, Layla Hughes, Ed Page, WaltParker, Jan Straley, Angelia Vanderlaan, Janet Whaley, and BillWilson. Chris Taggart provided particularly valuable substantiveinput and editorial support. NSB Mayor Edward Itta is thanked forhis support and vision. This project was funded by the NorthSlope Borough and the Arctic Research Initiative of the WoodsHole Oceanographic Institution. Bowhead whale images wererecorded under the authority of Permit no. 814-1899 to the NorthSlope Borough.

Appendix A. Supplementary materials

Supplementary data associated with this article can be foundin the online version at doi:10.1016/j.marpol.2011.08.005.

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