Endangered and Threatened Species; Proposed Threatened Status for Subspecies of the Ringed Seal, 77476-77495 [2010-30934]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 75, Number 237 (Friday, December 10, 2010)]
[Proposed Rules]
[Pages 77476-77495]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-30934]



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Part VII





Department of Commerce





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National Oceanic and Atmospheric Administration



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50 CFR Part 223



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

Federal Register / Vol. 75 , No. 237 / Friday, December 10, 2010 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 223

[Docket No. 101126590-0589-01]
RIN 0648-XZ59


Endangered and Threatened Species; Proposed Threatened Status for 
Subspecies of the Ringed Seal

AGENCY: National Marine Fisheries Service, National Oceanic and 
Atmospheric Administration, 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 
ringed seal (Phoca hispida) under the Endangered Species Act (ESA) and 
announce a 12-month finding on a petition to list the ringed seal as a 
threatened or endangered species. Based on consideration of information 
presented in the status review report, an assessment of the factors in 
the ESA, and efforts being made to protect the species, we have 
determined the Arctic (Phoca hispida hispida), Okhotsk (Phoca hispida 
ochotensis), Baltic (Phoca hispida botnica), and Ladoga (Phoca hispida 
ladogensis) subspecies of the ringed seal are likely to become 
endangered throughout all or a significant portion of their range in 
the foreseeable future. Accordingly, we issue a proposed rule to list 
these subspecies of the ringed seal as threatened species, and we 
solicit comments on this proposed action. At this time, we do not 
propose to designate critical habitat for the Arctic ringed seal 
because it is not currently determinable. In order to complete the 
critical habitat designation process, we also solicit information on 
essential physical and biological features of Arctic ringed seal 
habitat.

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-XZ59, 
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 ringed, bearded (Erignathus barbatus), 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 ringed, bearded, 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 ringed seal (and the bearded seal) and submit this 12-
month finding to the Office of the Federal Register by December 3, 
2010. Our 12-month petition finding for bearded 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 ringed 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's 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 ringed 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

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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 time frame. 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 
ringed seal is presented in the status review report (Kelly et al., 
2010a; available at https://alaskafisheries.noaa.gov/).
    The ringed seal is the smallest of the northern seals, with typical 
adult body sizes of 1.5 m in length and 70 kg in weight. The average 
life span of ringed seals is about 15-28 years. As the common name of 
this species suggests, its coat is characterized by ring-shaped 
markings. Ringed seals are adapted to remaining in heavily ice-covered 
areas throughout the fall, winter, and spring by using the stout claws 
on their fore flippers to maintain breathing holes in the ice.

Seasonal Distribution, Habitat Use, and Movements

    Ringed seals are circumpolar and are found in all seasonally ice 
covered seas of the Northern Hemisphere as well as in certain 
freshwater lakes. They range throughout the Arctic Basin and southward 
into adjacent seas, including the southern Bering Sea and Newfoundland. 
Ringed seals are also found in the Sea of Okhotsk and Sea of Japan in 
the western North Pacific, the Baltic Sea in the North Atlantic, and 
landlocked populations inhabit lakes Ladoga and Saimaa east of the 
Baltic Sea (Figure 1).
    Throughout most of its range, the Arctic subspecies does not come 
ashore and uses sea ice as a substrate for resting, pupping, and 
molting. During the ice-free season in more southerly regions including 
the White Sea, the Sea of Okhotsk, and the Baltic Sea, ringed seals 
occasionally rest on island shores or offshore reefs. In lakes Ladoga 
and Saimaa, ringed seals typically rest on rocks and island shores when 
ice is absent. In all subspecies except the Okhotsk, pups normally are 
born in subnivean lairs (snow caves) on the sea ice (Arctic and Baltic 
ringed seals) or in subnivean lairs along shorelines (Saimaa and Ladoga 
ringed seals) in late winter to early spring. Although use of subnivean 
lairs has been reported for Okhotsk ringed seals, this subspecies 
apparently depends primarily on sheltering in the lee of ice hummocks.
    The seasonality of ice cover strongly influences ringed seal 
movements, foraging, reproductive behavior, and vulnerability to 
predation. Born et al. (2004) recognized three ``ecological seasons'' 
as important to ringed seals off northwestern Greenland: The ``open-
water season,'' the ice-covered ``winter,'' and ``spring,'' when the 
seals breed and after the breeding season haul out on the ice to molt. 
Tracking seals in Alaska and the western Canadian Arctic, Kelly et al. 
(2010b) used different terms to refer to these ecological seasons. 
Kelly et al. (2010b) referred to the open-water period when ringed 
seals forage most intensively as the ``foraging period,'' early winter 
through spring when seals rest primarily in subnivean lairs on the ice 
as the ``subnivean period,'' and the period between abandonment of the 
lairs and ice break-up as the ``basking period.''
    Open-water (foraging) period: Short and long distance movements by 
ringed seals have been documented during the open-water period. 
Overall, the record from satellite tracking indicates that ringed seals 
breeding in shorefast ice practice one of two strategies during the 
open-water foraging period. Some seals forage within 100 km of their 
shorefast ice breeding habitat while others make extensive movements of 
hundreds or thousands of kilometers to forage in highly productive 
areas and along the pack ice edge. Movements during the open-water 
period by ringed seals that breed in the pack ice are unknown. Tracking 
and observational records indicate that adult Arctic ringed seals 
breeding in the shorefast ice show inter-annual fidelity to breeding 
sites. Saimaa and Ladoga ringed seals show similar site fidelity. High 
quality, abundant food is important to the annual energy budgets of 
ringed seals. Fall and early winter periods, prior to the occupation of 
breeding sites, are important in allowing ringed seals to accumulate 
enough fat stores to support estrus and lactation.

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    Winter (subnivean period): At freeze-up in fall, ringed seals 
surface to breathe in the remaining open water of cracks and leads. As 
these openings freeze over, the seals push through the ice to breathe 
until it is too thick. They then open breathing holes by abrading the 
ice with the claws on their fore flippers. As the ice thickens, the 
seals continue to maintain the breathing holes by scratching at the 
walls. The breathing holes can be maintained in ice 2 m or greater in 
thickness but often are concentrated in the thinner ice of refrozen 
cracks.
    As snow accumulates and buries the breathing hole, the seals 
breathe through the snow layer. Ringed seals excavate lairs in the snow 
above breathing holes where snow depth is sufficient. These subnivean 
lairs are occupied for resting, pupping, and nursing young in annual 
shorefast and pack ice. Snow accumulation on sea ice is typically 
sufficient for lair formation only where pressure ridges or ice 
hummocks cause the snow to form drifts at least 45 cm deep (at least 
50-65 cm for birth lairs). Such drifts typically occur only where 
average snow depths (on flat ice) are 20-30 cm or more. A general lack 
of such ridges or hummocks in lakes Ladoga and Saimaa limits suitable 
snow drifts to island shorelines, where most lairs in Lake Ladoga and 
virtually all lairs in Lake Saimaa are found.
    Subnivean lairs provide refuge from air temperatures too low for 
survival of ringed seal pups. Lairs also conceal ringed seals from 
predators, an advantage especially important to the small pups that 
start life with minimal tolerance for immersion in cold water. When 
forced to flee into the water to avoid predators, the pups that survive 
depend on the subnivean lairs to subsequently warm themselves. Ringed 
seal movements during the subnivean period typically are quite limited, 
especially where ice cover is extensive.
    Spring (basking period): Numbers of ringed seals hauled out on the 
surface of the ice typically begin to increase during spring as the 
temperatures warm and the snow covering the seals' lairs melts. 
Although the snow cover can melt rapidly, the ice remains largely 
intact and serves as a substrate for the molting seals that spend many 
hours basking in the sun. Adults generally molt from mid-May to mid-
July, although there is regional variation. The relatively long periods 
of time that ringed seals spend out of the water during the molt has 
been ascribed to the need to maintain elevated skin temperatures. 
Feeding is reduced and the seal's metabolism declines during the molt. 
As seals complete this phase of the annual pelage cycle, they spend 
increasing amounts of time in the water.

Food Habits

    Ringed seals eat a wide variety of prey in the marine environment. 
Most ringed seal prey is small, and preferred fishes tend to be 
schooling species that form dense aggregations. Ringed seals rarely 
prey upon more than 10-15 species in any one area, and not more than 2-
4 of those species are considered important prey. Despite regional and 
seasonal variations in the diet of ringed seals, fishes of the cod 
family tend to dominate the diet of ringed seals from late autumn 
through early spring in many areas. Arctic cod (Boreogadus saida) is 
often reported to be among the most important prey species, especially 
during the ice-covered periods of the year. Other members of the cod 
family, including polar cod (Arctogadus glacialis), saffron cod 
(Eleginus gracilis), and navaga (Eleginus navaga), are also seasonally 
important to ringed seals in some areas. Arctic cod is not found in the 
Sea of Okhotsk, but capelin (Mallotus villosus) are abundant in the 
region. Other fishes reported to be locally important to ringed seals 
include smelt (Osmerus sp.) and herring (Clupea sp.). Invertebrates 
appear to become more important to ringed seals in many areas during 
the open-water season, and are often found to dominate the diets of 
young seals. In the brackish water of the Baltic Sea, the prey 
community includes a mixture of marine and freshwater fish species, as 
well as invertebrates. In the freshwater environment of Lake Saimaa, 
several schooling fishes were reported to be the most important prey 
species; and in Lake Ladoga, a variety of fish species were found in 
the diet of ringed seals.

Reproduction

    Sexual maturity in ringed seals varies with population status and 
can be as late as 7 years for males and 9 years for females and as 
early as 3 years for both sexes. Ringed seals breed annually, with 
timing varying regionally. Mating takes place while mature females are 
still nursing their pups and is thought to occur under the ice in the 
vicinity of birth lairs. Little is known about the breeding system of 
ringed seals; however, males are often reported to be territorial 
during the breeding season.
    A single pup is born in a subnivean lair on either the shorefast 
ice or pack ice. In much of the Arctic, pupping occurs in late March 
through April, but the timing varies with latitude. Pupping in the Sea 
of Okhotsk takes place in March and April. In the Baltic Sea, Lake 
Saimaa, and Lake Ladoga, pups are born in February through March. At 
birth, ringed seal pups are approximately 60-65 cm in length and weigh 
4.5-5.0 kg with regional variation. The pups are born with a white 
natal coat (lanugo) that provides insulation, particularly when dry, 
until it is shed after 4-6 weeks. Pups nurse for as long as 2 months in 
stable shorefast ice and for as little as 3-6 weeks in moving ice. Pups 
normally are weaned before break-up of spring ice. At weaning, pups are 
four times their birth weights, and they lose weight for several months 
after weaning.

Species Delineation

    The BRT reviewed the best scientific and commercial data available 
on the ringed seal's taxonomy and concluded that there are five 
currently recognized subspecies of the ringed seal: Arctic ringed seal; 
Baltic ringed seal; Okhotsk ringed seal; Ladoga ringed seal; and Saimaa 
ringed seal (Phoca hispida saimensis). The BRT noted, however, that 
further investigation would be required to discern whether there are 
additional distinct units, especially within the Arctic subspecies, 
whose genetic structuring has yet to be thoroughly investigated. We 
agree with the BRT's conclusions that these five subspecies of the 
ringed seal qualify as ``species'' under the ESA. Our DPS analysis 
follows, and the geographic distributions of the five subspecies are 
shown in Figure 1.
    Under our DPS policy (61 FR 4722; February 7, 1996), two elements 
are considered in a decision regarding the potential identification of 
a DPS: (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

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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).
    With respect to discreteness criterion 1 above, we concluded that 
resolution of ringed seal population segments beyond the subspecies 
level is not currently possible using the best available scientific and 
commercial data. We also did not find sufficient differences in the 
conservation status or management within any of the ringed seal 
subspecies among their respective range countries to justify the use of 
international boundaries to satisfy the discreteness criterion of our 
DPS Policy. We therefore conclude that there are no population segments 
within any of the subspecies that satisfy the discreteness criteria of 
our DPS Policy. Since there are no discrete population segments within 
any of the subspecies, we cannot take the next step of determining 
whether any discrete population segment is significant to the taxon to 
which it belongs.
[GRAPHIC] [TIFF OMITTED] TP10DE10.089

Abundance and Trends

    Several factors make it difficult to accurately assess ringed 
seals' 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 ringed seals 
expensive and logistically

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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. Some studies have relied on 
surveys of seal holes and then estimated the number of seals based on 
various assumptions of the ratio of seals to holes. Most surveys are 
conducted during the basking period and the numbers of seals on ice is 
multiplied by some factor to estimate population size or determine a 
population index. While a few, recent studies have used data recorders 
and haul-out models to develop correction factors for seals submerged 
and unseen, many studies present only estimates for seals visible on 
ice (i.e., ``basking population''). The timing of annual snow and ice 
melts also varies widely from year to year and, unless surveys are 
conducted to coincide with similar ice and weather conditions, 
comparisons between years (even if conducted during the same time of 
year) can be erroneous. With these limitations in mind, the best 
scientific and commercial data on abundance and trends are summarized 
below for each of the ringed seal subspecies.

Arctic Ringed Seal

    The Arctic ringed seal is the most abundant of the ringed seal 
subspecies and has a circumpolar distribution. The BRT divided the 
distribution of Arctic ringed seals into five regions: Greenland Sea 
and Baffin Bay, Hudson Bay, Beaufort Sea, Chukchi Sea, and the White, 
Barents and Kara Seas. These regions were largely chosen to reflect the 
geographical groupings of published studies and not to imply any actual 
population structure. These areas also do not represent the full 
distribution of Arctic ringed seals as estimates are not available in 
some areas (e.g., areas of the Russian Arctic coast and the Canadian 
Arctic Archipelago).
    The only available comprehensive estimate for the Greenland Sea and 
Baffin Bay region is 787,000, based on surveys conducted in 1979. 
Consistency in harvest records over time lends some confidence that the 
population has not changed significantly.
    The Hudson Bay ringed seal population was estimated at 53,346 based 
on the mid-point of estimates from aerial surveys conducted in 2007 and 
2008. Prior surveys conducted in western Hudson Bay in the 1970s 
produced an estimate of 455,000 seals, which was much larger than the 
218,300 reported in the 1950s. The earlier studies did not account for 
seals using pack ice habitats which might account for the difference. A 
more recent survey in 1995 provided an estimate of approximately 
280,000 seals when missed seals were accounted for.
    Population assessments of ringed seals in the Beaufort and Chukchi 
Seas have been mostly confined to U.S. and Canadian waters. Based on 
the available abundance estimates for study areas within this region 
and extrapolations for pack ice areas without survey data, a reasonable 
estimate for the Chukchi and Beaufort Seas is 1 million seals. 
Estimates derived for all Alaskan shorefast ice habitats in both the 
Chukchi and Beaufort Seas based on aerial surveys conducted in the mid 
1980s were 250,000 ringed seals in the shorefast ice and 1-1.5 million 
including seals in the pack-ice habitat.
    The White, Barents, Kara, and East Siberian Seas encompass at least 
half of the worldwide distribution of Arctic ringed seals. The total 
population across these seas may be as many as 220,000 seals based on 
available survey data, primarily from 1975-1993.

Okhotsk Ringed Seal

    Based on aerial surveys, ringed seal abundance in the Sea of 
Okhotsk from 1968-1990 was estimated at between 676,000 and 855,000 
seals. These estimates include a general (not species-specific) 30 
percent adjustment to account for seals in the water. Fluctuations in 
population estimates since catch limits were initiated in 1968 were 
suspected to be natural (Fedoseev, 2000). Based on these surveys, a 
conservative estimate of the current total population of ringed seals 
in the Sea of Okhotsk would be 676,000 seals. Aerial surveys conducted 
in the Sea of Okhotsk from 1968-1969 provided a population estimate of 
800,000. This was the same as the estimate previously back-calculated 
from catch data in 1966 when a population decline due to hunting was 
identified. These calculations also suggested that ringed seal 
abundance in the Sea of Okhotsk had been in a state of steady decline 
since 1955 when estimates suggested the population exceeded 1 million 
seals.

Baltic Ringed Seal

    The Baltic ringed seal population was estimated at 10,000 seals 
based on comprehensive surveys conducted in 1996. Historical estimates 
of population size for the Baltic ringed seal range from 50,000 to 
450,000 seals in 1900 (Kokko et al., 1999). These estimates were 
derived as back calculations from historical bounty records. The large 
range in the estimates reflects uncertainty in the hunting dynamics and 
whether the populations were historically subject to density 
dependence. By the 1940s, the population had been reduced to 25,000 
seals in large part due to Swedish and Finnish removal efforts. Ringed 
seals in the Baltic are found in three general regions, the Bothnian 
Bay, Gulf of Finland, and Gulf of Riga plus the Estonian west coast. 
Low numbers of ringed seals are also present in the Bothnian Sea and 
the southwestern region of Finland. The greatest concentration of 
Baltic ringed seals is found in the Bothnian Bay.

Ladoga Ringed Seal

    The population size of ringed seals in Lake Ladoga is currently 
suggested to range between 3,000 and 5,000 seals based on an aerial 
survey in 2001. This represents a decline from estimates of 20,000 and 
5,000-10,000 seals reported for the 1930s and the 1960s, respectively 
(Chapskii, 1974). Results from a Russian aerial survey in the 1970s 
estimated the population of ringed seals in Lake Ladoga to be 3,500-
4,700 seals.

Saimaa Ringed Seal

    The current population estimate of ringed seals in Lake Saimaa is 
less than 300, and the mean population growth rate from 1990-2004 was 
1.026. Lake Saimaa is a complex body of water, and the population 
trends and abundance for Saimaa ringed seals have differed across the 
various regions. It has been projected that the population of Saimaa 
ringed seals may reach 400 by 2015, but with the caveat that seals may 
no longer be present in some regions of the lake. Historical abundance 
of ringed seals in Lake Saimaa is estimated to have been between 4,000 
and 6,000 animals approximately 5,000 years ago (Sipil[auml] and 
Hyv[auml]rinen, 1998; Sipil[auml], 2006). However, using a back-casting 
process based on reported bounty statistics, the population was 
estimated in 1893 to be between 100 and 1,300 seals. In 1993, the 
Saimaa seal was listed as endangered under the ESA (58 FR 26920; May 6, 
1993) and as depleted under the U.S. Marine Mammal Protection Act of 
1972, as amended. At that time, the population was estimated at 160-180 
seals (57 FR 60162; December 18, 1992).

Summary of Factors Affecting the Ringed 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

[[Page 77481]]

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 each subspecies of 
the ringed seal 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 the five subspecies of the ringed 
seal (see ADDRESSES). As discussed above, the data on ringed seal 
abundance and trends of most populations are unavailable or imprecise, 
especially in the Arctic and Okhotsk subspecies, and there is little 
basis for quantitatively linking projected environmental conditions or 
other factors to ringed 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 ringed 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 each of the subspecies of the 
ringed seal therefore requires a focus on the observed and projected 
changes in sea ice, snow cover, ocean temperature, ocean pH (acidity), 
and associated changes in ringed seal prey species.
    The threats (analyzed below) associated with impacts of the warming 
climate on the habitat of ringed seals, to the extent that they may 
pose risks to these seals, are expected to manifest throughout the 
current breeding and molting range (for snow and ice related threats) 
or throughout the entire range (for ocean warming and acidification) of 
each of the subspecies, 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 Ringed Seal's Sea Ice Habitat
    Sea ice in the Northern Hemisphere can be divided into 
first[hyphen]year sea ice that formed in the most recent 
autumn[hyphen]winter period, and multi[hyphen]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, the Baltic Sea, Hudson Bay, and 
the Sea of Okhotsk are known as seasonal ice zones, where first year 
sea ice is renewed every winter. Similarly, freshwater ice in lakes 
Ladoga and Saimaa forms and melts annually. Both the observed and the 
projected effects of a warming global climate are most extreme in 
northern high[hyphen]latitude regions, in large part due to the 
ice[hyphen]albedo feedback mechanism in which melting of snow and sea 
ice lowers reflectivity and thereby further increases surface warming 
by absorption of solar radiation.
    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 ringed 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[hyphen]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[hyphen]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 the 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 increases in 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, 
global warming projected 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

[[Page 77482]]

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 2 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 and snow 
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 ringed seals, we therefore considered all the projections through 
the end of the 21st century 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 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. Snow cover on sea 
ice in the Northern Hemisphere was forecasted using one of the six 
models, the Community Climate System Model, version 3 (CCSM3, National 
Center for Atmospheric Research) (under the A1B scenario), a model that 
is known for incorporating advanced sea ice physics, and for which snow 
data were available. To incorporate natural variability, this model was 
run seven times.
    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 14 different regions throughout the ringed seal's 
range, including 12 regions for the Arctic ringed seal, one region for 
the Okhotsk ringed seal, and one region for the Baltic, Ladoga, and 
Saimaa ringed seals. For Arctic ringed seals, in three regions (Chukchi 
Sea, east Siberian Sea, and the central Arctic) 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, in two regions (western Bering and the Barents 
Seas) a single model (CCSM3) met the performance criteria, and in five 
regions (Baffin Bay, Hudson Bay, the Canadian Arctic Archipelago, east 
Greenland, and the Kara and Laptev Seas) none of the models performed 
satisfactorily. The models also did not meet the performance criteria 
for the Baltic region and 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), other 
existing analyses (Baltic Sea and Hudson Bay), and results from the 
hemispheric predictions (Baffin Bay, the Canadian Arctic Archipelago, 
and the East Greenland, Kara, and Laptev Seas), were used for regions 
where ice projections could not be obtained. For the Baltic Sea we 
reviewed the analysis of Jylha et al. (2008). They used seven regional 
climate models and found good agreement with observations for the 1902-
2000 comparison period. 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.
    Regional predictions of snow cover were based on results from the 
hemispheric projections for Arctic and Okhotsk ringed seals, and on 
other existing analyses for Baltic, Ladoga, and Saimaa ringed seals. 
For the Baltic Sea we referred to the analysis of Jylha et al. (2008) 
noted above. For lakes Ladoga and Saimaa we considered the analysis of 
Saelthun et al. (1998; cited in Kuusisto, 2005). They used a modified 
hydrological model to analyze the effects of climate change on 
hydrological conditions and runoff in Finland and the Scandinavian 
Peninsula.
    While our inferences about future regional ice and snow 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 the onset of potential impacts to ringed seals is 
complicated by the coarse resolution of the IPCC models.

[[Page 77483]]

Northern Hemisphere Sea Ice and Snow Cover Predictions
    Projections of Northern Hemisphere sea ice concentrations 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 in November 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. The month of May shows diminishing 
sea ice cover at 2050 and 2090 in the Barents and Bering Seas and the 
Sea of Okhotsk. By the month of June, projections begin to show 
substantial changes as the century progresses. Current conditions 
occasionally exhibit a lack of sea ice near the Bering Strait during 
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 in the Arctic 
by mid-century.
    As the Arctic Ocean warms and is covered by less ice, precipitation 
is expected to increase overall including during the winter months. 
Five climate models used by the Arctic Climate Impact Assessment 
forecasted an average increase in precipitation over the Arctic Ocean 
of 14 percent by the end of the century (Walsh et al., 2005). The 
impact of increased winter precipitation on the depth of snow on sea 
ice, however, will be counteracted by delays in the formation of sea 
ice. Over most of the Arctic Ocean, snow cover reaches its maximal 
depth in May, but most of that accumulation takes place in the autumn 
(Sturm et al., 2002). Snow depths reach 50 percent of the annual 
maximum by the end of October and 67 percent of their maximum by the 
end of November (Radionov et al., 1997). Thus, delays of 1-2 months in 
the date of ice formation would result in substantial decreases in 
spring snow depths despite the potential for increased winter 
precipitation. Thinner ice will be more susceptible to deforming and 
producing pressure ridges and ice hummocks favoring snow drifts where 
depths exceed those on flat ice (Iacozaa and Barber, 1999; Strum  et 
al., 2006). However, as noted above, average snow depths of 20-30 cm or 
more are typically necessary to form drifts that are deep enough for 
ringed seal lair formation. As spring air temperatures continue to 
warm, snow melt will continue to come earlier in the year. The CCSM3 
model forecasted that the accumulation of snow on sea ice will decrease 
by almost 50 percent by the end of this century, with more than half of 
that decline projected to occur by 2050. Although the forecasted snow 
accumulations in the seven integrations of the model varied, all 
predicted substantial declines over the century.
Regional Sea Ice and Snow Cover Predictions by Subspecies
    Arctic ringed seal: In the East Siberian, Chukchi, Beaufort, Kara-
Laptev, and Greenland Seas, as well as in Baffin Bay, and the Canadian 
Arctic Archipelago, little or no decline in ice extent is expected in 
April and May during the remainder of this century. In most of these 
areas, a moderate decline in sea ice is predicted during June within 
this century, while substantial declines in sea ice are projected in 
July and November after mid-century. The central Arctic (defined as 
regions north of 80[deg] N. latitude) also shows declines in sea ice 
cover that are most apparent in July and November after 2050. For 
Hudson Bay, under a warmer climate scenario (for the years 2041-2070) 
Joly et al. (2010) projected a reduction in the sea ice season of 7-9 
weeks, with substantial reductions in sea ice cover most apparent in 
July and during the first months of winter.
    In the Bering Sea, April and May ice cover is projected to decline 
throughout this century, with substantial inter-annual variability 
forecasted in the eastern Bering Sea. The projection for May indicates 
that there will commonly be years with little or no ice in the western 
Bering Sea beyond mid-century. Very little ice has remained in the 
eastern Bering Sea in June since the mid-1970s. Sea ice cover in the 
Barents Sea in April and May is also projected to decline throughout 
this century, and in the months of June and July, ice is expected to 
disappear rapidly in the coming decades.
    Based on model projections, April snow depths over much of the 
range of the Arctic ringed seal averaged 25-35 cm in the first decade 
of this century, consistent with on-ice measurements by Russian 
scientists (Weeks, 2010). By mid-century, a substantial decrease in 
areas with April snow depths of 25-35 cm is projected (much of it 
reduced to 20-15 cm). The deepest snow (25-30 cm) is forecasted to be 
found just north of Greenland, in the Canadian Arctic Archipelago, and 
in an area tapering north from there into the central Arctic Basin. 
Southerly regions, such as the Bering Sea and Barents Sea, are 
forecasted to have snow depths of 10 cm or less my mid-century. By the 
end of the century, April snow depths of 20-25 cm are forecasted only 
for a portion of the central Arctic, most of the Canadian Arctic 
Archipelago, and a few small, isolated areas in a few other regions. 
Areas with 25-30 cm of snow are projected to be limited to a few small 
isolated pockets in the Canadian Arctic by 2090-2099.
    Okhotsk ringed seal: As noted above, none of the IPCC models 
performed satisfactorily at projecting sea ice for the Sea of Okhotsk, 
and so projected surface air temperatures were examined relative to 
current climate conditions as a proxy to predict sea ice extent and 
duration. Based on that analysis, ice is expected to persist in the Sea 
of Okhotsk in March during the remainder of this century, although ice 
may be limited to the northern region in most years after mid-century. 
Conditions for sea ice in April are likely to be limited to the far 
northern reaches of the Sea of Okhotsk or non-existent by 2100. Little 
to no sea ice is expected in May by mid-century. Average snow depth 
projections for April show depths of 15-20 cm only in the northern 
portions of the Sea of Okhotsk in the past 10 years and nowhere in that 
sea by mid-century. By the end of the century average snow depths are 
projected to be 10 cm or less even in the northern Sea of Okhotsk.

[[Page 77484]]

    Baltic, Ladoga, and Saimaa ringed seals: For the Baltic Sea, the 
analysis of regional climate models by Jylh[auml] et al. (2008) was 
considered. They used seven regional climate models and found good 
agreement with observations for the 1902-2000 comparison period. For 
the forecast period 2071-2100, one model predicted a change to mostly 
mild conditions, while the remaining models predicted unprecedentedly 
mild conditions. They noted that their estimates for a warming climate 
were in agreement with other studies that found unprecedentedly mild 
ice extent conditions in the majority of years after about 2030. The 
model we used to project snow depths (CCSM3) did not provide adequate 
resolution for the Baltic Sea. The climate models analyzed by 
Jylh[auml] et al. (2008), however, forecasted decreases of 45-60 days 
in duration of snow cover by the end of the century in the northern 
Baltic Sea region. The shortened seasonal snow cover would result 
primarily from earlier spring melts, but also from delayed onset of 
snow cover. Depth of snow is forecasted to decrease 50-70 percent in 
the region over the same period. The depth of snow also will be 
decreased by mid-winter thaws and rain events. Simulations of the snow 
cover indicated that an increasing proportion of the snow pack will 
consist of icy or wet snow.
    Ice cover has diminished about 12 percent over the past 50 years in 
Lake Ladoga. Although we are not aware of any ice forecasts specific to 
lakes Ladoga and Saimaa, the simulations of future climate reported by 
Jylh[auml] et al. (2008) suggest warming winters with reduced ice and 
snow cover. Snow cover in Finland and the Scandinavian Peninsula is 
projected to decrease 10-30 percent before mid-century and 50-90 
percent by 2100 (Saelthun et al., 1998, cited in Kuusisto, 2005).
Effects of Changes in Ice and Snow Cover on Ringed Seals
    Ringed seals are vulnerable to habitat loss from changes in the 
extent or concentration of sea ice because they depend on this habitat 
for pupping, nursing, molting, and resting. The ringed seal's broad 
distribution, ability to undertake long movements, diverse diet, and 
association with widely varying ice conditions suggest resilience in 
the face of environmental variability. However, the ringed seal's long 
generation time and ability to produce only a single pup each year may 
limit its ability to respond to environmental challenges such as the 
diminishing ice and snow cover projected in a matter of decades. Ringed 
seals apparently thrived during glacial maxima and survived warm 
interglacial periods. How they survived the latter periods or in what 
numbers is not known. Declines in sea ice cover in recent decades are 
more extensive and rapid than any known for at least the last few 
thousand years (Polyak et al., 2010).
    Ringed seals create birth lairs in areas of accumulated snow on 
stable ice including the shore-fast ice over continental shelves along 
Arctic coasts, bays, and inter-island channels. While some authors 
suggest that shorefast ice is the preferred pupping habitat of ringed 
seals due to its stability throughout the pupping and nursing period, 
others have documented ringed seal pupping on drifting pack ice both 
nearshore and offshore. Both of these habitats can be affected by 
earlier warming and break-up in the spring, which shortens the length 
of time pups have to grow and mature in a protected setting. Harwood et 
al. (2000) reported that an early spring break-up negatively impacted 
the growth, condition, and apparent survival of unweaned ringed seal 
pups. Early break-up was believed to have interrupted lactation in 
adult females, which in turn, negatively affected the condition and 
growth of pups.
    Unusually heavy ice has also been implicated in shifting 
distribution, high winter mortality, and reduced productivity of ringed 
seals. It has been suggested that reduced ice thickness associated with 
warming in some areas could lead to increased biological productivity 
that might benefit ringed seals, at least in the short-term. However, 
any transitory and localized benefits of reduced ice thickness are 
expected to be outweighed by the negative effects of increased 
thermoregulatory costs and vulnerability of seal pups to predation 
associated with earlier ice break-up and reduced snow cover.
    Ringed seals, especially the newborn, depend on snow cover for 
protection from cold temperatures and predators. Occupation of 
subnivean lairs is especially critical when pups are nursed in late 
March-June. Ferguson et al. (2005) attributed low ringed seal 
recruitment in western Hudson Bay to decreased snow depth in April and 
May. Reduced snowfall results in less snow drift accumulation next to 
pressure ridges, and pups in lairs with thin snow cover are more 
vulnerable to predation than pups in lairs with thick snow cover 
(Hammill and Smith, 1989; Ferguson et al., 2005). When snow cover is 
insufficient, pups can also freeze in their lairs as documented in 1974 
when roofs of lairs in the White Sea were only 5-10 cm thick (Lukin and 
Potelov, 1978). Similarly, pup mortality from freezing and polar bear 
(Ursus maritimus) predation increased when unusually warm spring 
temperatures caused early melting near Baffin Island in the late 1970s 
(Smith and Hammill, 1980; Stirling and Smith, 2004). Prematurely 
exposed pups also are vulnerable to predation by wolves (Canis lupus) 
and foxes (Alopex lagopus and Vulpes vulpes)--as documented during an 
early snow melt in the White Sea in 1977 (Lukin, 1980)--and by gulls 
(Laridae) and ravens (Corvus corax) as documented in the Barents Sea 
(Gjertz and Lydersen, 1983; Lydersen and Gjertz, 1987; Lydersen et al., 
1987; Lydersen and Smith, 1989; Lydersen and Rig, 1990; Lydersen, 
1998). When lack of snow cover has forced birthing to occur in the 
open, some studies have reported that nearly 100 percent of pups died 
from predation (Kumlien, 1879; Lydersen et al., 1987; Lydersen and 
Smith, 1989; Smith et al., 1991; Smith and Lydersen, 1991). The high 
fidelity to birthing sites exhibited by ringed seals also makes them 
more susceptible to localized degradation of snow cover (Kelly et al., 
2010).
    Increased rain-on-snow events during the late winter also 
negatively impact ringed seal recruitment by damaging or eliminating 
snow-covered birth lairs, increasing exposure and the risk of 
hypothermia, and facilitating predation by polar bears and other 
predators. Stirling and Smith (2004) documented the collapse of 
subnivean lairs during unseasonal rains near southeastern Baffin Island 
and the subsequent exposure of ringed seals to hypothermia. They 
surmised that most of the pups that survived exposure to cold were 
eventually killed by polar bears, Arctic foxes, or possibly gulls. 
Stirling and Smith (2004) postulated that, should early season rain 
become regular and widespread in the future, mortality of ringed seal 
pups will increase, especially in more southerly parts of their range.
Potential Impacts of Projected Ice and Snow Cover Changes on Ringed 
Seals
    As discussed above, ringed seals divide their time between foraging 
in the water, and reproducing and molting out of the water, where they 
are especially vulnerable to predation. Females must nurse their pups 
for 1-2 months, and the small pups are vulnerable to cold temperatures 
and avian and mammalian predators on the ice, especially during the 
nursing period. Thus, a specific habitat requirement for ringed seals 
is adequate snow for the occupation of subnivean

[[Page 77485]]

lairs, especially in spring when pups are born and nursed.
    Northern Hemisphere snow cover has declined in recent decades and 
spring melt times have become earlier (ACIA, 2005). In most areas of 
the Arctic Ocean, snow melt advanced 1-6 weeks from 1979-2007. 
Throughout most of the ringed seal's range, snow melt occurred within a 
couple of weeks of weaning. Thus, in the past 3 decades, snow melts in 
many areas have been pre-dating weaning. Shifts in the timing of 
reproduction by other pinnipeds in response to changes in food 
availability have been documented. However, the ability of ringed seals 
to adapt to earlier snow melts by advancing the timing of reproduction 
will be limited by snow depths. As discussed above, over most of the 
Arctic Ocean, snow cover reaches its maximal depth in May, but most of 
that accumulation takes place in autumn. It is therefore unlikely that 
snow depths for bir