Endangered and Threatened Species; Proposed Threatened and Not Warranted Status for Subspecies and Distinct Population Segments of the Bearded Seal, 77496-77515 [2010-30931]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 75, Number 237 (Friday, December 10, 2010)]
[Proposed Rules]
[Pages 77496-77515]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-30931]



[[Page 77496]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 101126591-0588-01]
RIN 0648-XZ58


Endangered and Threatened Species; Proposed Threatened and Not 
Warranted Status for Subspecies and Distinct Population Segments of the 
Bearded Seal

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

ACTION: Proposed rule; 12-month petition finding; status review; 
request for comments.

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SUMMARY: We, NMFS, have completed a comprehensive status review of the 
bearded seal (Erignathus barbatus) under the Endangered Species Act 
(ESA) and announce a 12-month finding on a petition to list the bearded 
seal as a threatened or endangered species. The bearded seal exists as 
two subspecies: Erignathus barbatus nauticus and Erignathus barbatus 
barbatus. Based on the findings from the status review report and 
consideration of the factors affecting these subspecies, we conclude 
that E. b. nauticus consists of two distinct population segments 
(DPSs), the Beringia DPS and the Okhotsk DPS. Moreover, based on 
consideration of information presented in the status review report, an 
assessment of the factors in section 4(a)(1) of the ESA, and efforts 
being made to protect the species, we have determined the Beringia DPS 
and the Okhotsk DPS are likely to become endangered throughout all or a 
significant portion of their ranges in the foreseeable future. We have 
also determined that E. b. barbatus is not in danger of extinction or 
likely to become endangered throughout all or a significant portion of 
its range in the foreseeable future. Accordingly, we are now issuing a 
proposed rule to list the Beringia DPS and the Okhotsk DPS of the 
bearded seal as threatened species. No listing action is proposed for 
E. b. barbatus. We solicit comments on this proposed action. At this 
time, we do not propose to designate critical habitat for the Beringia 
DPS because it is not currently determinable. In order to complete the 
critical habitat designation process, we solicit information on the 
essential physical and biological features of bearded seal habitat for 
the Beringia DPS.

DATES: Comments and information regarding this proposed rule must be 
received by close of business on February 8, 2011. Requests for public 
hearings must be made in writing and received by January 24, 2011.

ADDRESSES: Send comments to Kaja Brix, Assistant Regional 
Administrator, Protected Resources Division, Alaska Region, NMFS, Attn: 
Ellen Sebastian. You may submit comments, identified by RIN 0648-XZ58, 
by any one of the following methods:
     Electronic Submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal https://www.regulations.gov.
     Mail: P.O. Box 21668, Juneau, AK 99802.
     Fax: (907) 586-7557.
     Hand delivery to the Federal Building: 709 West 9th 
Street, Room 420A, Juneau, AK.
    All comments received are a part of the public record. No comments 
will be posted to https://www.regulations.gov for public viewing until 
after the comment period has closed. Comments will generally be posted 
without change. All Personal Identifying Information (for example, 
name, address, etc.) voluntarily submitted by the commenter may be 
publicly accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    We will accept anonymous comments (enter N/A in the required 
fields, if you wish to remain anonymous). You may submit attachments to 
electronic comments in Microsoft Word, Excel, WordPerfect, or Adobe PDF 
file formats only.
    The proposed rule, maps, status review report and other materials 
relating to this proposal can be found on the Alaska Region Web site 
at: https://alaskafisheries.noaa.gov/.

FOR FURTHER INFORMATION CONTACT: Tamara Olson, NMFS Alaska Region, 
(907) 271-5006; Kaja Brix, NMFS Alaska Region, (907) 586-7235; or Marta 
Nammack, Office of Protected Resources, Silver Spring, MD, (301) 713-
1401.

SUPPLEMENTARY INFORMATION: On March 28, 2008, we initiated status 
reviews of bearded, ringed (Phoca hispida), and spotted seals (Phoca 
largha) under the ESA (73 FR 16617). On May 28, 2008, we received a 
petition from the Center for Biological Diversity to list these three 
species of seals as threatened or endangered under the ESA, primarily 
due to concerns about threats to their habitat from climate warming and 
loss of sea ice. The Petitioner also requested that critical habitat be 
designated for these species concurrent with listing under the ESA. 
Section 4(b)(3)(B) of the ESA of 1973, as amended (16 U.S.C. 1531 et 
seq.) requires that when a petition to revise the List of Endangered 
and Threatened Wildlife and Plants is found to present substantial 
scientific and commercial information, we make a finding on whether the 
petitioned action is (a) Not warranted, (b) warranted, or (c) warranted 
but precluded from immediate proposal by other pending proposals of 
higher priority. This finding is to be made within 1 year of the date 
the petition was received, and the finding is to be published promptly 
in the Federal Register.
    After reviewing the petition, the literature cited in the petition, 
and other literature and information available in our files, we found 
(73 FR 51615; September 4, 2008) that the petition met the requirements 
of the regulations under 50 CFR 424.14(b)(2), and we determined that 
the petition presented substantial information indicating that the 
petitioned action may be warranted. Accordingly, we proceeded with the 
status reviews of bearded, ringed, and spotted seals and solicited 
information pertaining to them.
    On September 8, 2009, the Center for Biological Diversity filed a 
lawsuit in the U.S. District Court for the District of Columbia 
alleging that we failed to make the requisite 12-month finding on its 
petition to list the three seal species. Subsequently, the Court 
entered a consent decree under which we agreed to finalize the status 
review of the bearded seal (and the ringed seal) and submit this 12-
month finding to the Office of the Federal Register by December 3, 
2010. Our 12-month petition finding for ringed seals is published as a 
separate notice concurrently with this finding. Spotted seals were also 
addressed in a separate Federal Register notice (75 FR 65239; October 
22, 2010; see also, 74 FR 53683, October 20, 2009).
    The status review report of the bearded seal is a compilation of 
the best scientific and commercial data available concerning the status 
of the species, including the past, present, and future threats to this 
species. The Biological Review Team (BRT) that prepared this report was 
composed of eight marine mammal biologists, a fishery biologist, a 
marine chemist, and a climate scientist from NMFS' Alaska and Northeast 
Fisheries Science Centers, NOAA's Pacific Marine Environmental Lab, and 
the U.S. Fish and Wildlife Service (USFWS). The status review report 
underwent independent peer review by five scientists with expertise in 
bearded

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seal biology, Arctic sea ice, climate change, and ocean acidification.

ESA Statutory, Regulatory, and Policy Provisions

    There are two key tasks associated with conducting an ESA status 
review. The first is to delineate the taxonomic group under 
consideration; and the second is to conduct an extinction risk 
assessment to determine whether the petitioned species is threatened or 
endangered.
    To be considered for listing under the ESA, a group of organisms 
must constitute a ``species,'' which section 3(16) of the ESA defines 
as ``any subspecies of fish or wildlife or plants, and any distinct 
population segment of any species of vertebrate fish or wildlife which 
interbreeds when mature.'' The term ``distinct population segment'' 
(DPS) is not commonly used in scientific discourse, so the USFWS and 
NMFS developed the ``Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act'' to 
provide a consistent interpretation of this term for the purposes of 
listing, delisting, and reclassifying vertebrates under the ESA (61 FR 
4722; February 7, 1996). We describe and use this policy below to guide 
our determination of whether any population segments of this species 
meet the DPS criteria of the DPS policy.
    The ESA defines the term ``endangered species'' as ``any species 
which is in danger of extinction throughout all or a significant 
portion of its range.'' The term ``threatened species'' is defined as 
``any species which is likely to become endangered within the 
foreseeable future throughout all or a significant portion of its 
range.'' The foreseeability of a species' future status is case 
specific and depends upon both the foreseeability of threats to the 
species and foreseeability of the species' response to those threats. 
When a species is exposed to a variety of threats, each threat may be 
foreseeable in a different timeframe. For example, threats stemming 
from well-established, observed trends in a global physical process may 
be foreseeable on a much longer time horizon than a threat stemming 
from a potential, though unpredictable, episodic process such as an 
outbreak of disease that may never have been observed to occur in the 
species.
    In the 2008 status review of the ribbon seal (Boveng et al., 2008; 
see also 73 FR 79822, December 30, 2008), NMFS scientists used the same 
climate projections used in our risk assessment here, but terminated 
the analysis of threats to ribbon seals at 2050. One reason for that 
approach was the difficulty of incorporating the increased divergence 
and uncertainty in climate scenarios beyond that time. Other reasons 
included the lack of data for threats other than those related to 
climate change beyond 2050, and the fact that the uncertainty embedded 
in the assessment of the ribbon seal's response to threats increased as 
the analysis extended farther into the future.
    Since that time, NMFS scientists have revised their analytical 
approach to the foreseeability of threats and responses to those 
threats, adopting a more threat-specific approach based on the best 
scientific and commercial data available for each respective threat. 
For example, because the climate projections in the Intergovernmental 
Panel on Climate Change's (IPCC's) Fourth Assessment Report extend 
through the end of the century (and we note the IPCC's Fifth Assessment 
Report, due in 2014, will extend even farther into the future), we used 
those models to assess impacts from climate change through the end of 
the century. We continue to recognize that the farther into the future 
the analysis extends, the greater the inherent uncertainty, and we 
incorporated that limitation into our assessment of the threats and the 
species' response. For other threats, where the best scientific and 
commercial data does not extend as far into the future, such as for 
occurrences and projections of disease or parasitic outbreaks, we 
limited our analysis to the extent of such data. We believe this 
approach creates a more robust analysis of the best scientific and 
commercial data available.

Species Information

    A thorough review of the taxonomy, life history, and ecology of the 
bearded seal is presented in the status review report (Cameron et al., 
2010; available at https://alaskafisheries.noaa.gov/). The bearded seal 
is the largest of the northern ice-associated seals, with typical adult 
body sizes of 2.1-2.4 m in length and weight up to 360 kg. Bearded 
seals have several distinctive physical features including a wide 
girth; a small head in proportion to body size; long whiskers; and 
square-shaped fore flippers. The life span of bearded seals is about 
20-25 years.
    Bearded seals have a circumpolar distribution south of 85[deg] N. 
latitude, extending south into the southern Bering Sea in the Pacific 
and into Hudson Bay and southern Labrador in the Atlantic. Bearded 
seals also occur in the Sea of Okhotsk south to the northern Sea of 
Japan (Figure 1). Two subspecies of bearded seals are widely 
recognized: Erignathus barbatus nauticus inhabiting the Pacific sector, 
and Erignathus barbatus barbatus often described as inhabiting the 
Atlantic sector (Rice, 1998). The geographic distributions of these 
subspecies are not separated by conspicuous gaps. There are regions of 
intergrading generally described as somewhere along the northern 
Russian and central Canadian coasts (Burns, 1981; Rice, 1998).
    Although the validity of the division into subspecies has been 
questioned (Kosygin and Potelov, 1971), the BRT concluded, and we 
concur, that the evidence discussed in the status review report for 
retaining the two subspecies is stronger than any evidence for 
combining them. The BRT defined geographic boundaries for the divisions 
between the two subspecies, subject to the strong caveat that distinct 
boundaries do not appear to exist in the actual populations; and 
therefore, there is considerable uncertainty about the best locations 
for the boundaries. The BRT defined 112[deg] W. longitude (i.e., the 
midpoint between the Beaufort Sea and Pelly Bay) as the North American 
delineation between the two subspecies (Figure 1). Following Heptner et 
al. (1976), who suggested an east-west dividing line at Novosibirskiye, 
the BRT defined 145[deg] E. longitude as the Eurasian delineation 
between the two subspecies in the Arctic (Figure 1).

Seasonal Distribution, Habitat Use, and Movements

    Bearded seals primarily feed on benthic organisms that are more 
numerous in shallow water where light can reach the sea floor. As such, 
the bearded seal's effective range is generally restricted to areas 
where seasonal sea ice occurs over relatively shallow waters, typically 
less than 200 m in depth (see additional discussion below).
    Bearded seals are closely associated with sea ice, particularly 
during the critical life history periods related to reproduction and 
molting, and they can be found in a broad range of different ice types. 
Sea ice provides the bearded seal and its young some protection from 
predators during the critical life history periods of whelping and 
nursing. It also allows molting bearded seals a dry platform to raise 
skin temperature and facilitate epidermal growth, and is important 
throughout the year as a platform for resting and perhaps 
thermoregulation. Of the ice-associated seals in the Arctic, bearded 
seals seem to be the least particular about the type and quality of ice 
on which they are observed. Bearded seals generally prefer

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ice habitat that is in constant motion and produces natural openings 
and areas of open water, such as leads, fractures, and polynyas for 
breathing, hauling out on the ice, and access to water for foraging. 
They usually avoid areas of continuous, thick, shorefast ice and are 
rarely seen in the vicinity of unbroken, heavy, drifting ice or large 
areas of multi-year ice. Although bearded seals prefer sea ice with 
natural access to the water, observations indicate that bearded seals 
are able to make breathing holes in thinner ice.
    Being so closely associated with sea ice, particularly pack ice, 
the seasonal movements and distribution of bearded seals are linked to 
seasonal changes in ice conditions. To remain associated with their 
preferred ice habitat, bearded seals generally move north in late-
spring and summer as the ice melts and retreats, and then move south in 
the fall as sea ice forms.
    The region that includes the Bering and Chukchi Seas is the largest 
area of continuous habitat for bearded seals. The Bering-Chukchi 
Platform is a shallow intercontinental shelf that encompasses about 
half of the Bering Sea, spans the Bering Strait, and covers nearly all 
of the Chukchi Sea. Bearded seals can reach the bottom everywhere along 
the shallow shelf, and so it provides them favorable foraging habitat. 
The Bering and Chukchi Seas are generally covered by sea ice in late 
winter and spring, and are mostly ice free in late summer and fall. As 
the ice retreats in the spring most adult bearded seals in the Bering 
Sea are thought to move north through the Bering Strait, where they 
spend the summer and early fall at the southern edge of the Chukchi and 
Beaufort Sea pack ice and at the wide, fragmented margin of multi-year 
ice. A smaller number of bearded seals, mostly juveniles, remain near 
the coasts of the Bering and Chukchi Seas for the summer and early 
fall. As the ice forms again in the fall and winter, most seals move 
south with the advancing ice edge through Bering Strait and into the 
Bering Sea where they spend the winter.
    There are fewer accounts of the seasonal movements of bearded seals 
in other areas. Compared to the dramatic long range seasonal movements 
of bearded seals in the Chukchi and Bering Seas, bearded seals are 
considered to be relatively sedentary over much of the rest of their 
range, undertaking more local movements in response to ice conditions. 
These differences may simply be the result of the general persistence 
of ice over shallow waters in the High Arctic. In the Sea of Okhotsk, 
bearded seals remain in broken ice as the sea ice expands and retreats, 
inhabiting the southern pack ice edge beyond the fast ice in winter and 
moving north toward shore in spring and summer. In the White, Barents, 
and Kara Seas, bearded seals also conduct seasonal migrations following 
the ice edge, as may bearded seals in Baffin Bay. Excluded by shorefast 
ice from much of the Canadian Arctic Archipelago during winter, bearded 
seals are scattered throughout many of the inlets and fjords of this 
region from July to October, though at least in some years, a portion 
of the population is known to overwinter in a few isolated open water 
areas north of Baffin Bay.
    Throughout most of their range, adult bearded seals are seldom 
found on land. However, some adults in the Sea of Okhotsk, and more 
rarely in a few other regions, use haul-out sites ashore in late summer 
and early autumn until ice floes begin to appear at the coast. This is 
most common in the western Sea of Okhotsk and along the coasts of 
western Kamchatka where bearded seals form numerous shore rookeries 
that can have tens to hundreds of individuals each.

Reproduction

    In general, female and male bearded seals attain sexual maturity 
around ages 5-6 and 6-7, respectively. Adult female bearded seals 
ovulate after lactation, and are presumably then receptive to males. 
Mating is believed to usually take place at the surface of the water, 
but it is unknown if it also occurs underwater or on land or ice, as 
observed in some other phocids. The social dynamics of mating in 
bearded seals are not well known; however, theories regarding their 
mating system have centered around serial monogamy and promiscuity, and 
on the nature of competition among breeding males to attract and gain 
access to females. Bearded seals vocalize during the breeding season, 
with a peak in calling during and after pup rearing. Male vocalizations 
are believed to advertise mate quality to females, signal competing 
males of a claim on a female, or proclaim a territory.
    During the winter and spring, as sea ice begins to break up, 
perinatal females find broken pack ice over shallow areas on which to 
whelp, nurse young, and molt. A suitable ice platform is likely a 
prerequisite to whelping, nursing, and rearing young (Heptner et al., 
1976; Burns, 1981; Reeves et al., 1992; Lydersen and Kovacs, 1999; 
Kovacs, 2002). Because bearded seals whelp on ice, populations have 
likely adapted their phenology to the ice regimes of the regions that 
they inhabit. Wide-ranging observations of pups generally indicate 
whelping occurs from March to May with a peak in April, but there are 
considerable geographical differences in reported timing, which may 
reflect real variation, but that may also result from inconsistent 
sighting efforts across years and locations. Details on the spatial 
distribution of whelping can be found in section 2.5.1 of the status 
review report.
    Females bear a single pup that averages 33.6 kg in mass and 131.3 
cm in length. Pups begin shedding their natal (lanugo) coats in utero, 
and they are born with a layer of subcutaneous fat. These 
characteristics are thought to be adaptations to entering the water 
soon after birth as a means of avoiding predation.
    Females with pups are generally solitary, tending not to aggregate. 
Pups enter the water immediately after or within hours of birth. Pups 
nurse on the ice, and by the time they are a few days old they spend 
half their time in the water. Recent studies using recorders and 
telemetry on pups have reported a lactation period of about 24 days, a 
transition to diving and more efficient swimming, mother-guided 
movements of greater than 10 km, and foraging while still under 
maternal care.
    Detailed studies on bearded seal mothers show they forage 
extensively, diving shallowly (less than 10 m), and spending only about 
10 percent of their time hauled out with pups and the remainder nearby 
at the surface or diving. Despite the relative independence of mothers 
and pups, their bond is described as strong, with females being 
unusually tolerant of threats in order to remain or reunite with pups. 
A mixture of crustaceans and milk in the stomachs of pups indicates 
that independent foraging occurs prior to weaning, at least in some 
areas.

Molting

    Adult and juvenile bearded seals molt annually, a process that in 
mature phocid seals typically begins shortly after mating. Bearded 
seals haul out of the water more frequently during molting, a behavior 
that facilitates higher skin temperatures and may accelerate shedding 
and regrowth of hair and epidermis. Though not studied in bearded 
seals, molting has been described as diffuse, with individuals 
potentially shedding hair throughout the year but with a pulse in the 
spring and summer. This is reflected in the wide range of estimates for 
the timing of molting, though these estimates are also based on 
irregular observations.
    The need for a platform on which to haul out and molt from late 
spring to mid-summer, when sea ice is rapidly melting and retreating, 
may necessitate movement for bearded seals between

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habitats for breeding and molting. In the Sea of Okhotsk, the spatial 
distribution of bearded seals is similar between whelping and molting 
seasons so only short movements occur. In contrast, bearded seals that 
whelp and mate in the Bering Sea migrate long distances to summering 
grounds at the ice edge in the Chukchi Sea, a period of movement that 
coincides with the observed timing of molting. Similar migrations prior 
to and during the molting period have been presumed for bearded seals 
in the White and southeastern Barents Seas to more easterly and 
northern areas of the Barents Sea, where ice persists through the 
summer. Also during the interval between breeding and molting, passive 
movements on ice over large distances have been postulated between the 
White and Barents Seas, and from there further east to the Kara Sea. A 
post-breeding migration of bearded seals to molting grounds has also 
been postulated to occur from the southern Laptev Sea westward into the 
eastern Kara Sea. In some locations where bearded seals use terrestrial 
haul-out sites seasonally, the molting period overlaps with this use. 
However, the molting phenology of bearded seals on shore is unknown.

Food Habits

    Bearded seals are considered to be foraging generalists because 
they have a diverse diet with a large variety of prey items throughout 
their circumpolar range. Bearded seals feed primarily on a variety of 
invertebrates and some fishes found on or near the sea bottom. They are 
also able to switch their diet to include schooling pelagic fishes when 
advantageous. The bulk of the diet appears to consist of relatively few 
prey types, primarily bivalve mollusks and crustaceans like crabs and 
shrimps. However, fishes like sculpins, Arctic cod (Boreogadus saida), 
polar cod (Arctogadus glacialis), or saffron cod (Eleginus gracilis) 
can also be a significant component. There is conflicting evidence 
regarding the importance of fish in the bearded seal diet throughout 
its range. Several studies have found high frequencies of fishes in the 
diet, but it is not known whether major consumption of fish is related 
to the availability of prey resources or the preferential selection of 
prey. Seasonal changes in diet composition have been observed 
throughout the year. For example, clams and fishes have been reported 
as more important in spring and summer months than in fall and winter.

Species Delineation

    The BRT reviewed the best scientific and commercial data available 
on the bearded seal's taxonomy and concluded that there are two widely 
recognized subspecies of bearded seals: Erignathus barbatus barbatus, 
often described as inhabiting the Atlantic sector of the seal's range; 
and Erignathus barbatus nauticus, inhabiting the Pacific sector of the 
range. Distribution maps published by Burns (1981) and Kovacs (2002) 
provide the known northern and southern extents of the distribution. As 
discussed above, the BRT defined geographic boundaries for the 
divisions between the two subspecies (Figure 1), subject to the strong 
caveat that distinct boundaries do not appear to exist in the actual 
populations. Our DPS analysis follows.
    Under our DPS policy (61 FR 4722; February 7, 1996) two elements 
are considered when evaluating whether a population segment qualifies 
as a DPS under the ESA: (1) The discreteness of the population segment 
in relation to the remainder of the species or subspecies to which it 
belongs; and (2) the significance of the population segment to the 
species or subspecies to which it belongs.
    A population segment of a vertebrate species may be considered 
discrete if it satisfies either one of the following conditions: (1) It 
is markedly separated from other populations of the same taxon as a 
consequence of physical, physiological, ecological, or behavioral 
factors. Quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation; or (2) it is 
delimited by international governmental boundaries within which 
differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the ESA.
    If a population segment is considered to be discrete under one or 
both of the above conditions, its biological and ecological 
significance to the taxon to which it belongs is evaluated in light of 
the ESA's legislative history indicating that the authority to list 
DPSs be used ``sparingly,'' while encouraging the conservation of 
genetic diversity (see Senate Report 151, 96th Congress, 1st Session). 
This consideration may include, but is not limited to, the following: 
(1) Persistence of the discrete population segment in an ecological 
setting unusual or unique for the taxon; (2) evidence that loss of the 
discrete population segment would result in a significant gap in the 
range of the taxon; (3) evidence that the discrete population segment 
represents the only surviving natural occurrence of a taxon that may be 
more abundant elsewhere as an introduced population outside its 
historic range; or (4) evidence that the discrete population segment 
differs markedly from other populations of the species in its genetic 
characteristics.
    If a population segment is discrete and significant (i.e., it is a 
DPS) its evaluation for endangered or threatened status will be based 
on the ESA's definitions of those terms and a review of the factors 
enumerated in section 4(a)(1).

Evaluation of Discreteness

    The range of the bearded seal occurs in cold, seasonally or 
annually ice-covered Arctic and subarctic waters, without persistent 
intrusions of warm water or other conditions that would pose potential 
physiological barriers. Furthermore, the seasonal timings of 
reproduction and molting vary little throughout the bearded seal's 
distribution, suggesting that there are no obvious ecological 
separation factors.
    The underwater vocalizations of males during the breeding season 
recorded in Alaskan, Canadian, and Norwegian waters are often more 
similar between adjacent geographical regions than between more distant 
sites, suggesting that bearded seals may have strong fidelity to 
specific breeding sites. However, these observed differences in 
vocalizations may be due to other factors such as ecological influences 
or sexual selection, and not to distance or geographic barriers. 
Bearded seals are known to make seasonal movements of greater than 
1,000 km, and so only very large geographical barriers would have the 
potential by themselves to maintain discreteness between breeding 
concentrations. As primarily benthic feeders, bearded seals may be 
constrained to relatively shallow waters and so expanses of deep water 
may also pose barriers to movement.
    Erignathus barbatus nauticus: Given the bearded seal's circumpolar 
distribution and their ability to travel long distances, it is 
difficult to imagine that land masses pose a significant barrier to the 
movement of this subspecies, with one exception: The great southerly 
extent of the Kamchatka Peninsula. The seasonal ice does not extend 
south to the tip of that peninsula, and the continental shelf is very 
narrow along its eastern Bering Sea coast. The seals' affinity for ice 
and shallow waters may help to confine bearded seals to their 
respective sea basins in the Bering and Okhotsk Seas. Heptner et al. 
(1976) and Krylov et al. (1964) described a typical annual pattern of 
bearded seals in the Sea of Okhotsk to be one of staying near the ice 
edge when ice is present, and then moving north and closer to shore as 
the

[[Page 77500]]

ice recedes in summer. Unlike other researchers describing tendencies 
of the species as a whole, Krylov et al. (1964) described the bearded 
seal as more or less sedentary, based primarily on observations of 
seals in the Sea of Okhotsk. Indeed, published maps indicate that the 
southeastern coast of the Kamchatka Peninsula is the only location 
where the distribution of the bearded seal is not contiguous (Burns, 
1981; Kovacs, 2002; Blix, 2005), and there are no known records of 
bearded seals moving between the Sea of Okhotsk and Bering Sea.
    Kosygin and Potelov (1971) conducted a study of craniometric and 
morphological differences between bearded seals in the White, Barents, 
and Kara Seas, and bearded seals in the Bering Sea and Sea of Okhotsk. 
They reported differences in measurements between the three regions, 
although they suggested that the differences were not significant 
enough to justify dividing the population into subspecies. Fedoseev 
(1973, 2000) also suggested that differences in the numbers of lip 
vibrissae as well as length and weight indicate population structure 
between the Bering and Okhotsk Seas. Thus, under the first factor for 
determining discreteness, the BRT concluded, and we concur, that the 
available evidence indicates the discreteness of two population 
segments: (1) The Sea of Okhotsk, and (2) the remainder of the range of 
E. b. nauticus, hereafter referred to as the Beringia population 
segment. Considerations of cross-boundary management do not outweigh or 
contradict the division proposed above based on biological grounds. In 
all countries in the range of the Beringia segment (Russia, United 
States, and Canada) annual harvest rates are considered small relative 
to the local populations and harvest is assumed to have little impact 
on abundance. In addition, if the Kamchatka Peninsula serves as a 
geographic barrier, the entire population of bearded seals in the Sea 
of Okhotsk may lie entirely within Russian jurisdiction.
    Erignathus barbatus barbatus: The Greenland and Norwegian Seas, 
which separate northern Europe and Russia from Greenland, form a very 
deep basin that could potentially act as a type of physical barrier to 
a primarily benthic feeder. Risch et al. (2007) described distinct 
differences in male vocalizations at breeding sites in Svalbard and 
Canada; however, they also suggested that ecological influences or 
sexual selection, and not a geographical feature restricting gene flow, 
could be the cause of these differences. Gjertz et al. (2000) described 
at least one pup known to travel from Svalbard nearly to the Greenland 
coast across Fram Strait, and Davis et al. (2008) failed to find a 
significant difference between populations on either side of the 
Greenland Sea. Both of these studies suggest that the expanse of deep 
water is apparently not a geographic barrier to bearded seals. However, 
it should be noted that not all of the DNA samples used in the study by 
Davis et al. (2008) were collected during the time of breeding, and so 
might not reflect the potential for additional genetic discreteness if 
discrete breeding groups disperse and mix during the non-breeding 
period. When considered altogether, the BRT concluded, and we concur, 
that subdividing E. b. barbatus into two or more DPSs is not warranted 
because the best scientific and commercial data available does not 
indicate that the populations are discrete.
    The core range of the bearded seal includes the waters of five 
countries (Russia, United States, Canada, Greenland, and Norway) with 
management regimes sufficiently similar that considerations of cross-
boundary management and regulatory mechanisms do not support a positive 
discreteness determination. In addition, in all countries in the range 
of E. b. barbatus, annual harvest rates are considered small relative 
to the local populations and harvest is assumed to have little impact 
on abundance. Since we conclude that the E. b. barbatus populations are 
not discrete, we do not address whether they would be considered 
significant.

Evaluation of Significance

    Having concluded that E. b. nauticus is composed of two discrete 
segments, here we review information that the BRT found informative for 
evaluating the biological and ecological significance of these 
segments.
    Throughout most of their range, adult bearded seals are rarely 
found on land (Kovacs, 2002). However, some adults in the Sea of 
Okhotsk, and more rarely in Hudson Bay (COSEWIC, 2007), the White, 
Laptev, Bering, Chukchi, and Beaufort Seas (Heptner et al., 1976; 
Burns, 1981; Nelson, 1981; Smith, 1981), and Svalbard (Kovacs and 
Lydersen, 2008) use haul-out sites ashore in late summer and early 
autumn. In these locations, sea ice either melts completely or recedes 
beyond the limits of shallow waters where seals are able to feed (Burns 
and Frost, 1979; Burns, 1981). By far the largest and most numerous and 
predictable of these terrestrial haul-out sites are in the Sea of 
Okhotsk, where they are distributed continuously throughout the bearded 
seal range, and may comprise tens to more than a thousand individuals 
(Scheffer, 1958; Tikhomorov, 1961; Krylov et al., 1964; Chugunkov, 
1970; Tavrovskii, 1971; Heptner et al., 1976; Burns, 1981). Indeed, the 
Sea of Okhotsk is the only portion of the range of E. b. nauticus 
reported to have any such aggregation of adult haul-out sites (Fay, 
1974; Burns and Frost, 1979; Burns, 1981; Nelson, 1981). Although it is 
not clear for how long bearded seals have exhibited this haul-out 
behavior, its commonness is unique to the Sea of Okhotsk, possibly 
reflecting responses or adaptations to changing conditions at the range 
extremes. This difference in haul-out behavior may also provide 
insights about the resilience of the species to the effects of climate 
warming in other regions.
    The Sea of Okhotsk covers a vast area and is home to many thousands 
of bearded seals. Similarly, the range of the Beringia population 
segment includes a vast area that provides habitat for many thousands 
of bearded seals. Loss of either segment of the subspecies' range would 
result in a substantially large gap in the overall range of the 
subspecies.
    The existence of bearded seals in the unusual or unique ecological 
setting found in the Sea of Okhotsk, as well as the fact that loss of 
either the Okhotsk or Beringia segment would result in a significant 
gap in the range of the taxon, support our conclusion that the Beringia 
and Okhotsk population segments of E. b. nauticus are each significant 
to the subspecies as a whole.

DPS Conclusions

    In summary, the Beringia and Okhotsk population segments of E. b. 
nauticus are discrete because they are markedly separated from other 
populations of the same taxon as a consequence of physical, 
physiological, ecological, and behavioral factors. They are significant 
because the loss of either of the two DPSs would result in a 
significant gap in the range of the taxon, and the Okhotsk DPS exists 
in an ecological setting that is unusual or unique for the taxon. We 
therefore conclude that these two population segments meet both the 
discreteness and significance criteria of the DPS policy. We consider 
these two population segments to be DPSs (the Beringia DPS and the 
Okhotsk DPS) (Figure 1).

[[Page 77501]]

[GRAPHIC] [TIFF OMITTED] TP10DE10.090

Abundance and Trends

    No accurate worldwide abundance estimates exist for bearded seals. 
Several factors make it difficult to accurately assess the bearded 
seal's abundance and trends. The remoteness and dynamic nature of their 
sea ice habitat, time spent below the surface and their broad 
distribution and seasonal movements make surveying bearded seals 
expensive and logistically challenging. Additionally, the species' 
range crosses political boundaries, and there has been limited 
international cooperation to conduct range-wide surveys. Details of 
survey methods and data are often limited or have not been published, 
making it difficult to judge the reliability of the reported numbers. 
Logistical challenges also make it difficult to collect the necessary 
behavioral data to make proper adjustments to seal counts. Until very 
recently, no suitable behavioral data have been available to correct 
for the proportion of seals in the water at the time of surveys. 
Research is just beginning to address these limitations, and so current 
and accurate abundance estimates are not yet available. We make 
estimates based on the best scientific and commercial data available, 
combining recent and historical data.

Beringia DPS

    Data analyzed from aerial surveys conducted in April and May 2007 
produced an abundance estimate of 63,200 bearded seals in an area of 
81,600 sq km in the eastern Bering Sea (Ver Hoef et al., 2010). This is 
a partial estimate for bearded seals in the U.S. waters of the Bering 
Sea because the survey area did not include some known bearded seal 
habitat in the eastern Bering Sea and north of St. Lawrence Island. The 
estimate is similar in magnitude to the western Bering Sea estimates 
reported by Fedoseev (2000) from surveys in 1974-1987, which ranged 
from 57,000 to 87,000. The BRT considers the current total Bering Sea 
bearded seal population to be about double the partial estimate 
reported by Ver Hoef et al. (2010) for U.S. waters, or approximately 
125,000 individuals.

[[Page 77502]]

    Aerial surveys flown along the coast from Shishmaref to Barrow 
during May-June 1999 and 2000 provided average annual bearded seal 
density estimates. A crude abundance estimate based on these densities, 
and without any correction for seals in the water, is 13,600 bearded 
seals. These surveys covered only a portion (U.S. coastal) of the 
Chukchi Sea. Assuming that the waters along the Chukchi Peninsula on 
the Russian side of the Chukchi Sea contain similar numbers of bearded 
seals, the combined total would be about 27,000 individuals.
    Aerial surveys of the eastern Beaufort Sea conducted in June during 
1974-1979, provided estimates that averaged 2,100 bearded seals, 
uncorrected for seals in the water. The ice-covered continental shelf 
of the western Beaufort Sea is roughly half the area surveyed, 
suggesting a crude estimate for the entire Beaufort Sea in June of 
about 3,150, uncorrected for seals in the water. For such a large area 
in which the subsistence use of bearded seals is important to Alaska 
Native and Inuvialuit communities, this number is likely to be a 
substantial underestimate. A possible explanation is that many of the 
subsistence harvests of bearded seals in this region may occur after a 
rapid seasonal influx of seals from the Bering and Chukchi Seas in the 
early summer, later than the period in which the surveys were flown.
    In the East Siberian Sea, Obukhov (1974) described bearded seals as 
rare, but present during July-September, based on year-round 
observations (1959-1965) of a region extending about 350 km east from 
the mouth of the Kolyma River. Typically, one bearded seal was seen 
during 200-250 km of travel. Geller (1957) described the zone between 
the Kola Peninsula and Chukotka as comparatively poor in marine mammals 
relative to the more western and eastern portions of the northern 
Russian coasts. We are not aware of any other information about bearded 
seal abundance in the East Siberian Sea.
    Although the present population size of the Beringia DPS is very 
uncertain, based on these reported abundance estimates, the current 
population size is estimated at 155,000 individuals.

Okhotsk DPS

    Fedoseev (2000) presented multiple years of unpublished seal survey 
data from 1968 to 1990; however, specific methodologies were not 
provided for any of the surveys or analyses. Most of these surveys were 
designed primarily for ringed and ribbon seals, as they were more 
abundant and of higher commercial value. Recognizing the sparse 
documentation of the survey methods and data, as well as the 20 years 
or more that have elapsed since the last survey, the BRT recommends 
considering the 1990 estimate of 95,000 individuals to be the current 
estimated population size of the Okhotsk DPS.

Erignathus barbatus barbatus

    Cleator (1996) suggested that a minimum of 190,000 bearded seals 
inhabit Canadian waters based on summing the different available 
indices for bearded seal abundance. The BRT recommends considering the 
current bearded seal population in Hudson Bay, the Canadian 
Archipelago, and western Baffin Bay to be 188,000 individuals. This 
value was chosen based on the estimate for Canadian waters of 190,000, 
minus 2,000 to account for the average number estimated to occur in the 
Canadian portion of the Beaufort Sea (which is part of the E. b. 
nauticus subspecies). There are few estimates of abundance available 
for other parts of the range of E. b. barbatus, and there is sparse 
documentation of the methods used to produce these estimates. 
Consequently, the BRT considered all regional estimates for E. b. 
barbatus to be unreliable, except for those in Canadian waters. The 
population size of E. b. barbatus is therefore very uncertain, but NMFS 
experts estimate it to be 188,000 individuals.

Summary of Factors Affecting the Bearded Seal

    Section 4(a)(1) of the ESA and the listing regulations (50 CFR part 
424) set forth procedures for listing species. We must determine, 
through the regulatory process, if a species is endangered or 
threatened because of any one or a combination of the following 
factors: (1) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (2) overutilization for 
commercial, recreational, scientific, or educational purposes; (3) 
disease or predation; (4) inadequacy of existing regulatory mechanisms; 
or (5) other natural or human-made factors affecting its continued 
existence. These factors are discussed below, with the Beringia DPS, 
the Okhotsk DPS, and E. b. barbatus considered under each factor. The 
reader is also directed to section 4.2 of the status review report for 
a more detailed discussion of the factors affecting bearded seals (see 
ADDRESSES). As discussed above, data on bearded seal abundance and 
trends of most populations are unavailable or imprecise, and there is 
little basis for quantitatively linking projected environmental 
conditions or other factors to bearded seal survival or reproduction. 
Our risk assessment therefore primarily evaluated important habitat 
features and was based upon the best available scientific and 
commercial data and the expert opinion of the BRT members.

A. Present or Threatened Destruction, Modification, or Curtailment of 
the Species' Habitat or Range

    The main concern about the conservation status of bearded seals 
stems from the likelihood that their sea ice habitat has been modified 
by the warming climate and, more so, that the scientific consensus 
projections are for continued and perhaps accelerated warming in the 
foreseeable future. A second concern, related by the common driver of 
carbon dioxide (CO2) emissions, is the modification of 
habitat by ocean acidification, which may alter prey populations and 
other important aspects of the marine ecosystem. A reliable assessment 
of the future conservation status of bearded seals therefore requires a 
focus on observed and projected changes in sea ice, ocean temperature, 
ocean pH (acidity), and associated changes in bearded seal prey 
species.
    The threats (analyzed below) associated with impacts of the warming 
climate on the habitat of bearded seals, to the extent that they may 
pose risks to these seals, are expected to manifest throughout the 
current breeding and molting range (for sea ice related threats) or 
throughout the entire range (for ocean warming and acidification) of 
each of the population units, since the spatial resolution of data 
pertaining to these threats is currently limited.
Overview of Global Climate Change and Effects on the Annual Formation 
of the Bearded Seal's Sea Ice Habitat
    Sea ice in the Northern Hemisphere can be divided into first-year 
sea ice that formed in the most recent autumn-winter period, and multi-
year sea ice that has survived at least one summer melt season. The 
Arctic Ocean is covered by a mix of multi-year sea ice. More southerly 
regions, such as the Bering Sea, Barents Sea, Baffin Bay, Hudson Bay, 
and the Sea of Okhotsk are known as seasonal ice zones, where first 
year sea ice is renewed every winter. Both the observed and the 
projected effects of a warming global climate are most extreme in 
northern high-latitude regions, in large part due to the ice-albedo 
feedback mechanism in which melting of snow and sea ice lowers 
reflectivity and thereby further increases surface warming by 
absorption of solar radiation.

[[Page 77503]]

    Sea ice extent at the end of summer (September) 2007 in the Arctic 
Ocean was a record low (4.3 million sq km), nearly 40 percent below the 
long-term average and 23 percent below the previous record set in 2005 
(5.6 million sq km) (Stroeve et al., 2008). Sea ice extent in September 
2010 was the third lowest in the satellite record for the month, behind 
2007 and 2008 (second lowest). Most of the loss of sea ice was on the 
Pacific side of the Arctic. Of even greater long-term significance was 
the loss of over 40 percent of Arctic multi-year sea ice over the last 
5 years (Kwok et al., 2009). While the annual minimum of sea ice extent 
is often taken as an index of the state of Arctic sea ice, the recent 
reductions of the area of multi-year sea ice and the reduction of sea 
ice thickness is of greater physical importance. It would take many 
years to restore the ice thickness through annual growth, and the loss 
of multi-year sea ice makes it unlikely that the Arctic will return to 
previous climatological conditions. Continued loss of sea ice will be a 
major driver of changes across the Arctic over the next decades, 
especially in late summer and autumn.
    Sea ice and other climatic conditions that influence bearded seal 
habitats are quite different between the Arctic and seasonal ice zones. 
In the Arctic, sea ice loss is a summer feature with a delay in freeze 
up occurring into the following fall. Sea ice persists in the Arctic 
from late fall through mid-summer due to cold and dark winter 
conditions. Sea ice variability is primarily determined by radiation 
and melting processes during the summer season. In contrast, the 
seasonal ice zones are free of sea ice during summer. The variability 
in extent, thickness, and other sea ice characteristics important to 
marine mammals is determined primarily by changes in the number, 
intensity, and track of winter and spring storms in the sub-Arctic. 
Although there are connections between sea ice conditions in the Arctic 
and the seasonal ice zones, the early loss of summer sea ice in the 
Arctic cannot be extrapolated to the seasonal ice zones, which are 
behaving differently than the Arctic. For example, the Bering Sea has 
had 4 years of colder than normal winter and spring conditions from 
2007 to 2010, with near record sea ice extents, rivaling the sea ice 
maximum in the mid-1970s, despite record retreats in summer.
IPCC Model Projections
    The analysis and synthesis of information presented by the IPCC in 
its Fourth Assessment Report (AR4) represents the scientific consensus 
view on the causes and future of climate change. The IPCC AR4 used a 
range of future greenhouse gas (GHG) emissions produced under six 
``marker'' scenarios from the Special Report on Emissions Scenarios 
(SRES) (IPCC, 2000) to project plausible outcomes under clearly-stated 
assumptions about socio-economic factors that will influence the 
emissions. Conditional on each scenario, the best estimate and likely 
range of emissions were projected through the end of the 21st century. 
It is important to note that the SRES scenarios do not contain explicit 
assumptions about implementation of agreements or protocols on emission 
limits beyond current mitigation policies and related sustainable 
development practices.
    Conditions such as surface air temperature and sea ice area are 
linked in the IPCC climate models to GHG emissions by the physics of 
radiation processes. When CO2 is added to the atmosphere, it 
has a long residence time and is only slowly removed by ocean 
absorption and other processes. Based on IPCC AR4 climate models, 
expected global warming--defined as the change in global mean surface 
air temperature (SAT)--by the year 2100 depends strongly on the assumed 
emissions of CO2 and other GHGs. By contrast, warming out to 
about 2040-2050 will be primarily due to emissions that have already 
occurred and those that will occur over the next decade. Thus, 
conditions projected to mid-century are less sensitive to assumed 
future emission scenarios. Uncertainty in the amount of warming out to 
mid-century is primarily a function of model-to-model differences in 
the way that the physical processes are incorporated, and this 
uncertainty can be addressed in predicting ecological responses by 
incorporating the range in projections from different models.
    Comprehensive Atmosphere-Ocean General Circulation Models (AOGCMs) 
are the major objective tools that scientists use to understand the 
complex interaction of processes that determine future climate change. 
The IPCC used the simulations from about two dozen AOGCMs developed by 
17 international modeling centers as the basis for the AR4 (IPCC, 
2007). The AOGCM results are archived as part of the Coupled Model 
Intercomparison Project-Phase 3 (CMIP3) at the Program for Climate 
Model Diagnosis and Intercomparison (PCMDI). The CMIP3 AOGCMs provide 
reliable projections, because they are built on well-known dynamical 
and physical principles, and they simulate quite well many large scale 
aspects of present-day conditions. However, the coarse resolution of 
most current climate models dictates careful application on small 
scales in heterogeneous regions.
    There are three main contributors to divergence in AOGCM climate 
projections: Large natural variations, the range in emissions 
scenarios, and across-model differences. The first of these, 
variability from natural variation, can be incorporated by averaging 
the projections over decades, or, preferably, by forming ensemble 
averages from several runs of the same model. The second source of 
variation arises from the range in plausible emissions scenarios. As 
discussed above, the impacts of the scenarios are rather similar before 
mid-21st century. For the second half of the 21st century, however, and 
especially by 2100, the choice of the emission scenario becomes the 
major source of variation among climate projections and dominates over 
natural variability and model-to-model differences (IPCC, 2007). 
Because the current consensus is to treat all SRES emissions scenarios 
as equally likely, one option for representing the full range of 
variability in potential outcomes would be to project from any model 
under all of the six ``marker'' scenarios. This can be impractical in 
many situations, so the typical procedure for projecting impacts is to 
use an intermediate scenario, such as A1B or B2 to predict trends, or 
one intermediate and one extreme scenario (e.g., A1B and A2) to 
represent a significant range of variability. The third primary source 
of variability results from differences among models in factors such as 
spatial resolution. This variation can be addressed and mitigated in 
part by using the ensemble means from multiple models.
    There is no universal method for combining AOGCMs for climate 
projections, and there is no one best model. The approach taken by the 
BRT for selecting the models used to project future sea ice conditions 
is summarized below.
Data and Analytical Methods
    NMFS scientists have recognized that the physical basis for some of 
the primary threats faced by the species had been projected, under 
certain assumptions, through the end of the 21st century, and that 
these projections currently form the most widely accepted version of 
the best available data about future conditions. In our risk assessment 
for bearded seals, we therefore considered the full 21st century 
projections to analyze the threats stemming from climate change.
    The CMIP3 (IPCC) model simulations used in the BRT analyses were 
obtained from PCMDI on-line (PCMDI, 2010). The

[[Page 77504]]

six IPCC models previously identified by Wang and Overland (2009) as 
performing satisfactorily at reproducing the magnitude of the observed 
seasonal cycle of sea ice extent in the Arctic under the A1B 
(``medium'') and A2 (``high'') emissions scenarios were used to project 
monthly sea ice concentrations in the Northern Hemisphere in March-July 
for each of the decadal periods 2025-2035, 2045-2055, and 2085-2095.
    Climate models generally perform better on continental or larger 
scales, but because habitat changes are not uniform throughout the 
hemisphere, the six IPCC models used to project sea ice conditions in 
the Northern Hemisphere were further evaluated independently on their 
performance at reproducing the magnitude of the observed seasonal cycle 
of sea ice extent in 12 different regions throughout the bearded seal's 
range, including five regions for the Beringia DPS, one region for the 
Okhotsk DPS, and six regions for E. b. barbatus. Models that met the 
performance criteria were used to project sea ice extent for the months 
of November and April-July through 2100. For the Beringia DPS, in two 
regions (Chukchi and east Siberian Seas) six of the models simulated 
sea ice conditions in reasonable agreement with observations, in two 
regions (Beaufort and eastern Bering Seas) four models met the 
performance criteria, and in the western Bering Sea a single model met 
the performance criteria. For E. b. barbatus, none of the models 
performed satisfactorily in six of the seven regions (a single model 
was retained in the Barents Sea). The models also did not meet the 
performance criteria for the Sea of Okhotsk. Other less direct means of 
predicting regional ice cover, such as comparison of surface air 
temperature predictions with past climatology (Sea of Okhotsk), 
evaluation of other existing analyses (Hudson Bay) or results from the 
hemispheric predictions (the Canadian Arctic Archipelago, Baffin Bay, 
Greenland Sea, and the Kara and Laptev Seas), were used for regions 
where ice projections could not be obtained. For Hudson Bay we referred 
to the analysis of Joly et al. (2010). They used a regional sea ice-
ocean model to investigate the response of sea ice and oceanic heat 
storage in the Hudson Bay system to a climate-warming scenario. These 
predicted regional sea ice conditions are summarized below in assessing 
the potential impacts of changes in sea ice on bearded seals.
    While our inferences about future regional ice conditions are based 
upon the best available scientific and commercial data, we recognize 
that there are uncertainties associated with predictions based on 
hemispheric projections or indirect means. We also note that judging 
the timing of onset of potential impacts to bearded seals is 
complicated by the coarse resolution of the IPCC models.
Northern Hemisphere Predictions
    Projections of Northern Hemisphere sea ice extent for November 
indicate a major delay in fall freeze-up by 2050 north of Alaska and in 
the Barents Sea. By 2090, the average sea ice concentration is below 50 
percent in the Russian Arctic and some models show a nearly ice free 
Arctic, except for the region of the Canadian Arctic Archipelago. In 
March and April, winter type conditions persist out to 2090. There is 
some reduction of sea ice by 2050 in the outer portions of the seasonal 
ice zones, but the sea ice south of Bering Strait, eastern Barents Sea, 
Baffin Bay, and the Kara and Laptev Seas remains substantial. May shows 
diminishing sea ice cover at 2050 and 2090 in the Barents and Bering 
Seas and Sea of Okhotsk. The month of June begins to show substantial 
changes as the century progresses. Current conditions occasionally 
exhibit a lack of sea ice near the Bering Strait by June. By 2050, 
however, this sea ice loss becomes a major feature, with open water 
continuing along the northern Alaskan coast in most models. Open water 
in June spreads to the East Siberian Shelf by 2090. The eastern Barents 
Sea experiences a reduction in sea ice between 2030 and 2050. The 
models indicate that sea ice in Baffin Bay will be affected very little 
until the end of the century.
    In July, the Arctic Ocean shows a marked effect of global warming, 
with the sea ice retreating to a central core as the century 
progresses. The loss of multi-year sea ice over the last 5 years has 
provided independent evidence for this conclusion. By 2050, the 
continental shelves of the Beaufort, Chukchi, and East Siberian Seas 
are nearly ice free in July, with ice concentrations less than 20 
percent in the ensemble mean projections. The Kara and Laptev Seas also 
show a reduction of sea ice in coastal regions by mid-century in most 
but not all models. The Canadian Arctic Archipelago and the adjacent 
Arctic Ocean north of Canada and Greenland, however, are predicted to 
become a refuge for sea ice through the end of the century. This 
conclusion is supported by typical Arctic wind patterns, which tend to 
blow onshore in this region. Indeed, this refuge region is why sea ice 
scientists use the phrase: A nearly sea ice free summer Arctic by mid-
century.
Potential Impacts of Changes in Sea Ice on Bearded Seals
    In order to feed on the seafloor, bearded seals are known to nearly 
always occupy shallow waters (Fedoseev, 2000; Kovacs, 2002). The 
preferred depth range is often described as less than 200 m (Kosygin, 
1971; Heptner et al., 1976; Burns and Frost, 1979; Burns, 1981; 
Fedoseev, 1984; Nelson et al., 1984; Kingsley et al., 1985; Fedoseev, 
2000; Kovacs, 2002), though adults have been known to dive to around 
300 m (Kovacs, 2002; Cameron and Boveng, 2009), and six of seven pups 
instrumented near Svalbard have been recorded at depths greater than 
488 m (Kovacs, 2002). The BRT defined the core distribution of bearded 
seals (e.g., whelping, nursing, breeding, molting, and most feeding) as 
those areas of known extent that are in water less than 500 m deep.
    An assessment of the risks to bearded seals posed by climate change 
must consider the species' life-history functions, how they are linked 
with sea ice, and how altering that link will affect the vital rates of 
reproduction and survival. The main functions of sea ice relating to 
the species' life-history are: (1) A dry and stable platform for 
whelping and nursing of pups in April and May (Kovacs et al., 1996; 
Atkinson, 1997); (2) a rearing habitat that allows mothers to feed and 
replenish energy reserves lost while nursing; (3) a habitat that allows 
a pup to gain experience diving, swimming, and hunting with its mother, 
and that provides a platform for resting, relatively isolated from most 
terrestrial and marine predators; (4) a habitat for rutting males to 
hold territories and attract post-lactating females; and (5) a platform 
suitable for extended periods of hauling out during molting.
    Whelping and nursing: Pregnant females are considered to require 
sea ice as a dry birthing platform (Kovacs et al., 1996; Atkinson, 
1997). Similarly, pups are thought to nurse only while on ice. If 
suitable ice cover is absent from shallow feeding areas during whelping 
and nursing, bearded seals would be forced to seek either sea ice 
habitat over deeper water or coastal regions in the vicinity of haul-
out sites on shore. A shift to whelping and nursing on land would 
represent a major behavioral change that could compromise the ability 
of bearded seals, particularly pups, to escape predators, as this is a 
highly developed response on ice versus land. Further, predators abound 
on continental shorelines, in contrast with

[[Page 77505]]

sea ice habitat where predators are sparse; and small islands where 
predators are relatively absent offer limited areas for whelping and 
nursing as compared to the more extensive substrate currently provided 
by suitable sea ice.
    Bearded seal mothers feed throughout the lactation period, 
continuously replenishing fat reserves lost while nursing pups 
(Holsvik, 1998; Krafft et al., 2000). Therefore, the presence of a 
sufficient food resource near the nursing location is also important. 
Rearing young in poorer foraging grounds would require mothers to 
forage for longer periods and (or) compromise their own body condition, 
both of which could impact the transfer of energy to offspring and 
affect survival of pups, mothers, or both.
    Pup maturation: When not on the ice, there is a close association 
between mothers and pups, which travel together at the surface and 
during diving (Lydersen et al, 1994; Gjertz et al., 2000; Krafft et 
al., 2000). Pups develop diving, swimming, and foraging skills over the 
nursing period, and perhaps beyond (Watanabe et al., 2009). Learning to 
forage in a sub-optimal habitat could impair a pup's ability to learn 
effective foraging skills, potentially impacting its long-term 
survival. Further, hauling out reduces thermoregulatory demands which, 
in Arctic climates, may be critical for maintaining energy balance. 
Hauling out is especially important for growing pups, which have a 
disproportionately large skin surface and rate of heat loss in the 
water (Harding et al., 2005; Jansen et al., 2010).
    Mating: Male bearded seals are believed to establish territories 
under the sea ice and exhibit complex acoustic and diving displays to 
attract females. Breeding behaviors are exhibited by males up to 
several weeks in advance of females' arrival at locations to give 
birth. Mating takes place soon after females wean their pups. The 
stability of ice cover is believed to have influenced the evolution of 
this mating system.
    Molting: There is a peak in the molt during May-June, when most 
bearded seals (except young of the year) tend to haul out