[Federal Register Volume 73, Number 250 (Tuesday, December 30, 2008)]
[Notices]
[Pages 79822-79828]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-31023]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[Docket No. 080318443-81628-02]
RIN 0648-XG53
Endangered and Threatened Wildlife; Notice of 12-Month Finding on
a Petition to List the Ribbon Seal as a Threatened or Endangered
Species
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Status review; notice of finding.
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SUMMARY: We, NMFS, announce a 12-month finding on a petition to list
the ribbon seal (Histriophoca fasciata) as a threatened or endangered
species under the Endangered Species Act of 1973 as amended (ESA).
After a formal review of the best available scientific and commercial
information, we find that listing of the ribbon seal is not warranted
at this time. Although the ribbon seal population abundance is likely
to decline gradually for the foreseeable future, primarily from slight
but chronic impacts on reproduction and survival caused by reduced
frequency of years with sea ice of suitable extent, quality, and
duration of persistence, it is not in danger of extinction or likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.
DATES: The finding announced in this notice was made on December 30,
2008.
ADDRESSES: Information used to make this finding is available for
public inspection by appointment during
[[Page 79823]]
normal business hours at the office of NMFS Alaska Region, Protected
Resources Division, 709 West Ninth Street, Room 461, Juneau, AK 99801.
This file includes the status review report, information provided by
the public, and scientific and commercial information gathered for the
status review. The ribbon seal petition and the status review report
can also be found at http://www.fakr.noaa.gov/protectedresources/seals/ice.htm.
FOR FURTHER INFORMATION CONTACT: James Wilder, NMFS Alaska Region,
telephone (907) 271-6620; Kaja Brix, NMFS Alaska Region, (907) 586-
7235; or Marta Nammack, NMFS, Office of Protected Resources, (301) 713-
1401.
SUPPLEMENTARY INFORMATION: On December 20, 2007, we received a petition
from the Center for Biological Diversity to list the ribbon seal as a
threatened or endangered species under the ESA, primarily due to
concern about threats to this species' habitat from climate warming and
loss of sea ice. The Petitioner also requested that critical habitat be
designated for ribbon seals concurrently with listing under the ESA.
Section 4(b)(3)(B) of the ESA 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 listing by other pending
proposals of higher priority. This finding is to be made within 12
months 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
that the petition met the requirements of the regulations under 50 CFR
424.14(b)(2) and determined that the petition presented substantial
information indicating that the petitioned action may be warranted.
This finding was published on March 28, 2008 (73 FR 16617). At that
time, we commenced a status review of ribbon seals and solicited
information pertaining to the species. We concurrently initiated status
reviews of three other ice seals (ringed (Phoca hispida), bearded
(Erignathus barbatus), and spotted (Phoca largha). These reviews are
still ongoing. The status review of the ribbon seal is a compilation of
the best available information concerning the status of ribbon seals,
including the past, present, and future threats to this species. The
Biological Review Team (BRT) that conducted the status review was
composed of scientists with expertise in the biology and ecology of
ribbon seals and with expertise in fisheries from NMFS' Alaska
Fisheries Science Center and a climate expert from NOAA's Pacific
Marine Environmental Lab. The Status Review produced by the BRT was
reviewed by four independent scientific experts, three of whom have
expertise in the biology and ecology of Arctic marine mammal species,
and specifically with ribbon seals, and the fourth expert is a climate
scientist. The reviewers agreed with the conclusions of the status
review and provided detailed comment, which the BRT addressed in the
final draft of the document.
There are two key tasks associated with conducting an ESA status
review. The first is to determine whether the petitioned entity
qualifies as one or more species under the ESA; if so, or if we
determine that there is a larger entity that includes the petitioned
entity and qualifies as a species under the ESA, the second task is to
conduct an extinction risk assessment to determine whether the species
is threatened or endangered. 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.'' For this status review, the
foreseeable future was determined to be the year 2050 because past and
current emissions of greenhouse gases have already largely set the
course for changes in the atmosphere and climate until that time, and
because of enormous uncertainty about future social and political
decisions on emissions that will dominate projection of conditions
farther into the future. Beyond the year 2050, projections of climate
scenarios are too heavily dependent on socio economic assumptions and
are therefore too divergent for reliable use in assessing threats to
ribbon seals.
It is important to note that our approach to establishing the
appropriate time frame for the foreseeable future, as noted above, was
the same as the approach used by the U.S. Fish & Wildlife Service
(USFWS) in its recent decision listing the polar bear as threatened
under the ESA (73 FR 28212). Although not relied on as the basis for
determining ``foreseeable future'' in the polar bear listing, the USFWS
also noted that the mid century threshold for reliable assessment of
threats will occur in about three polar bear generation lengths, or a
total of 45 years from now, a measure that had been used previously by
polar bear scientific expert groups as an appropriate time frame over
which to evaluate polar bear population trends for determining the
conservation status of the species. Coincidentally, the generation
length of the ribbon seal (defined as the average age of the parents of
an annual cohort or as the average age at which females give birth) is
likely to be similar to that of the polar bear, approximately 12 15
years. However, for the reasons stated above related to the uncertainty
in climate change projections beyond 2050, we believe that using 2050
as the foreseeable future is more appropriate with respect to ribbon
seals than using a specific number of generation lengths to support or
adjust the time frame for the foreseeable future. For species with
overlapping generations, like the ribbon seal, facing threats that are
primarily extrinsic, such as habitat destruction, commercial harvest,
or incidental mortality in fisheries, the generation length may be
essentially irrelevant; threats could undermine a population over the
course of many generations or, conceivably, in less than one. Moreover,
the time required to detect a specific change or trend in a population
depends mostly on the precision of population estimates, not the
generation time of the species. Therefore, and in summary, we
determined that the best available scientific information allows
reliable assessment of global warming and the related threats to ribbon
seals through 2050. Further discussion of how the foreseeable future
was defined for this analysis can be found in Section 4.1, Time Frame:
The Foreseeable Future, of the Status Review of the Ribbon Seal.
Species Background
The ribbon seal is a strikingly marked member of the family
Phocidae that primarily inhabits the Sea of Okhotsk, and the Bering and
Chukchi Seas. This species is strongly associated with the sea ice
during its whelping, mating, and pelage molt periods, from mid March
through June. Most of the rest of the year is spent at sea; the species
is rarely observed on land. The rates of survival and reproduction are
not well known, but ribbon seals can live 20 to 30 years. They become
sexually mature at 1 to 5 years of age, probably depending on
environmental conditions, and adult females usually give birth every
year to a single pup which is nursed for 3 to 4 weeks and then
abandoned to fend for itself.
[[Page 79824]]
Species Delineation
The ESA provides for listing species, subspecies, or distinct
population segments (DPSs) of vertebrate species. When we evaluate a
petition to list an entity as threatened or endangered under the ESA,
we must first determine whether the petitioned entity qualifies as a
species under the ESA. The Petitioner requested that we list the ribbon
seal species as threatened or endangered. When conducting a status
review, we can also evaluate the status of DPSs of a vertebrate species
to determine whether one or more warrant listing under the ESA.
The joint NMFS/ USFWS policy on the Recognition of Distinct
Vertebrate Population Segments (DPS) Under the Endangered Species Act
(61 FR 4722; February 7, 1996) describes two criteria that a population
segment must meet in order to be considered a DPS: (1) discreteness
from other conspecific population segments; and (2) significance to the
taxon to which it belongs. Although there are two main breeding areas
for ribbon seals, one in the Sea of Okhotsk and one in the Bering Sea,
there is currently no evidence of discrete populations on which to base
a separation into DPSs. Therefore, the entire global population was
considered to comprise the species for the purpose of assessing
extinction risk. More detail on this determination can be found in
Section 3 of the Status Review, Species Delineation. In assessing
extinction risk, the BRT considered whether any of the threats set
forth below posed a risk to the species throughout all or a significant
portion of its range, as a species may be endangered or threatened even
if it is at risk in only a significant portion of its range.
Extinction Risk Assessment
To assess the extinction risk, the BRT evaluated the risks based on
specific demographic factors of the species, such as abundance,
productivity, spatial structure, and diversity, as these relate to the
specific threats faced by the species outlined in section 4(a)(1) of
the ESA. These threats are the present or threatened destruction,
modification, or curtailment of its habitat or range; overutilization
for commercial, recreational, scientific, or educational purposes;
disease or predation; the inadequacy of existing regulatory mechanisms;
or other natural or manmade factors affecting its continued existence.
We evaluated whether these factors caused a risk of extinction
throughout all or a significant portion of the ribbon seal's range.
Demographic Factors
With a population likely comprising at least 200,000 individuals,
ribbon seals are not currently at risk from the demographic issues of
low abundance commonly associated with ESA listing decisions, such as
demographic stochasticity, inbreeding, loss of genetic diversity, and
depensatory effects. Aerial surveys were conducted in portions of the
eastern Bering Sea by the National Marine Mammal Laboratory (NMML) in
2003, 2007, and 2008. The data from these surveys are currently being
analyzed to construct estimates of abundance for the eastern Bering Sea
from frequencies of sightings, ice distribution, and the timings of
seal haul out behavior. In the interim, NMML researchers have developed
a provisional population estimate of 49,000 ribbon seals in the eastern
and central Bering Sea. Using restrictive assumptions, this number was
scaled according to distributions of ribbon seal breeding areas in 1987
to produce total Bering Sea estimates ranging from 98,000 to 190,000.
Similar scaling based on a rangewide distribution produced Bering Sea,
Sea of Okhotsk, and total range estimates of 115,000, 100,000, and
215,000, respectively. The current population trend is unknown, but the
recent estimate of 49,000 ribbon seals in the eastern and central
Bering Sea is consistent enough with historical estimates to suggest
that no major or catastrophic change has occurred in recent decades.
The species is thought to occupy its entire historically observed
range. There are no portions of their range in which ribbon seals have
been reported to have disappeared, nor are they known to be
demographically at risk in any portion of their range. Further detail
on historic and current abundance and trends can be found in Section
2.9 of the ribbon seal status review.
Present or Threatened Destruction, Modification, or Curtailment of the
Species' Habitat or Range
The main concerns about the conservation status of the ribbon seal
stem from the likelihood that its 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 reliable assessment of the future conservation
status of ribbon seals, therefore, requires a focus on projected
changes to specific regional conditions, particularly sea ice, which
could impact vital rates.
Unlike the Arctic Ocean, where sea ice is present year round, the
ice in the Bering Sea and Sea of Okhotsk is seasonal in nature. The
main thermodynamic physical influence at high latitudes is the cold and
darkness that occurs in winter. Therefore, despite the recent dramatic
reductions in Arctic Ocean ice extent during summer, the sea ice in the
northern Bering Sea and Sea of Okhotsk is expected to continue forming
annually in winter for the foreseeable future. The future central
Arctic will also continue to be an ice covered sea in winter, but will
contain more first year sea ice than multi year ice.
Ice extent in marginal seas such as the Bering Sea is characterized
not by summer minima since these seas have been ice free in summer
throughout recorded history but rather by winter maxima. Freezing
conditions in the northern Bering Sea persist from December through
April. Mean monthly maximum temperatures at Nome, Alaska (a sub Arctic
maritime climate station located at 64[deg] N), are -3[deg]C or below
for all months November through April. Freezing rather than thawing
should still predominate in these months even if a hypothesized ~3[deg]
C global warming signal is realized. The result is that the seasonal
formation of sea ice in the northern Bering Sea and Sea of Okhotsk is
substantially decoupled from the summer ice extent in the Arctic Ocean,
and is expected to continue annually through the foreseeable future,
along with typical, large interannual variations in extent and duration
of persistence.
Large areas of sea ice in the ribbon seal's range will form and
persist in most years through May; the occurrence of extensive ice in
June will be highly variable, as it has been in the past. Nevertheless,
in association with a long term warming trend there will likely be
changes in the frequency of years with extensive ice, the quality of
ice, and the duration of its persistence that may impact the amount of
suitable habitat in the geographic areas that ribbon seals have
preferred in the past. An assessment of the risks posed by these
changes must consider the ribbon seal life history functions associated
with sea ice and the potential effects on the vital rates of
reproduction and survival.
Despite the recent dramatic reductions in Arctic Ocean ice extent
during summer, the sea ice in the northern Bering Sea and Sea of
Okhotsk is expected to continue forming annually in winter for the
foreseeable future. As mentioned above, the sea ice regimes in the
Bering Sea and Sea of Okhotsk will continue to be subject to
[[Page 79825]]
large interannual variations in extent and seasonal duration, as they
have been throughout recorded history. While there may be more frequent
years in which sea ice coverage is reduced, the late March to early May
period in which the peak of ribbon seal reproduction occurs will
continue to have substantial ice for the foreseeable future. Still,
there will likely be more frequent years in which the ice is confined
to the northern regions of the observed breeding range.
In contrast to harp seals (Pagophilus groenlandicus), which are
their closest relatives, ribbon seals are much less closely tied to
traditional geographic locations for important life history functions
such as whelping and molting. In years of low ice it is likely that
ribbon seals will adjust, at least in part, by shifting their breeding
locations in response to the position of the ice edge, as they have
likely done in the past in response to interannual variability. For
example, observations indicate that extreme dispersal of ribbon seals
within their effective range is associated with years of unusual ice
conditions. The formation of extensive ice in the Bering and Okhotsk
Seas has been found to result in the occurrence of large numbers of
these seals further south than they normally occur. The reverse is also
true.
There has not been, however, any study that would verify whether
vital rates of reproduction or survival have been affected by these
interannual variations in ice extent and breeding. Whelping, nursing of
pups, and maturation of weaned pups could conceivably be impacted in
years when the ice does not extend as far south as it has typically in
the past, because the breeding areas would be farther from the
continental shelf break, a zone that seems to be a preferred foraging
area during spring. If these conditions occur more frequently, as is
anticipated from projections of future climate and sea ice conditions,
reproduction and survival of young could be impacted. Lacking relevant
data, the most conservative approach is to assume that the population
has been at equilibrium with respect to conditions in the past, and
that a change such as more frequent breeding farther from preferred
foraging habitats will have some impact on vital rates. Even given the
uncertainties, we conclude that the anticipated slight increase in
frequency of years with low ice extent in April and May is likely to
have some impact on reproductive rates.
As described in Section 2.5 of the status review, ribbon seals have
an apparent affinity for stable, clean, moderate sized ice floes that
are slightly, but not deeply interior to the pack ice edge. For the
foreseeable future, ice of this type is likely to occur annually in the
Bering Sea and Sea of Okhotsk, but it may be confined more frequently
to smaller areas, or areas farther north, than in the past. The
availability of moderately thick, stable ice floes could potentially
influence ribbon seal demography, particularly in May, via survival
rates of weaned pups. Pups spend a great deal of time on the ice during
a transition period of 2 3 weeks following weaning, presumably
developing their capabilities for self sufficient foraging. They enter
the water regularly during this period, and therefore may not be
particularly sensitive to modest reductions in ice coverage or quality.
Thus, although they are likely dependent on ice, weaned pups may not
require ice floes that can persist for weeks to meet their basic haul
out needs. Though uncertain, it is possible that the weaned pups will
be relatively limited in their capability to respond to rapidly
deteriorating ice fields by relocating over large distances, a factor
that could occur more frequently in the foreseeable future.
Subadult ribbon seals, which molt earlier than adults during March
to mid May, and which are not constrained by habitat requirements for
whelping and breeding, may be the least sensitive to the availability
and quality of sea ice. For example, in 2007, NMFS research cruises in
the Bering Sea encountered subadult ribbon seals in approximately the
expected proportions. Of 31 ribbon seals caught, 6 were subadults, 22
were adults, and 3 were young of the year (which were commonly
encountered but not always pursued for tagging). In other words, the
obvious presence of seals in the subadult age class did not indicate
that catastrophic losses had occurred in the ribbon seal cohorts
produced during the warm years of 2001 2005.
Adult ribbon seals, which are the last to molt, might be expected
to be the most sensitive to timing of the ice melt. Stable ice is
critical during this period, and ribbon seals have been observed to
rarely enter the water during this time. The pelage molt of phocid
seals is generally thought to be facilitated or enhanced by elevated
skin temperatures that can be achieved when hauled out versus in the
water. For example, it has been suggested that the harbor seal (Phoca
vitulina, a small phocid, similar in size and body composition to a
ribbon seal), could not complete its molt entirely in the water at
temperatures that the species would normally encounter in the wild.
Analysis of haul out records (Section 2.6, Life History, of the status
review) indicate that individual adult ribbon seals haul out almost
continuously for a period of 2 3 weeks, mostly during mid May to late
June, corresponding to the observed peak in molting. Therefore,
decreased availability of stable platforms for adults to complete their
molt out of the water may also lower survival, but it is not currently
possible to quantify this impact or the extent to which ribbon seals
may adapt by shifting locations for molting.
Sea ice coverage in June will likely be low or absent more
frequently in the foreseeable future. The implications of a loss of
access to a haul out substrate during this period are unknown, but they
may include energetic costs, increased susceptibility to skin disorders
and pathogens, and possibly increased exposure to any risks from which
the hair normally protects a seal (e.g., abrasion from crawling over
snow and ice). However, the ultimate effect on adult survival rate is
currently difficult or impossible to model.
These impacts on ribbon seal survival in years of low ice extent,
poor ice quality, or early melting are all of a sort that would not
necessarily be significant in any one year; a year of low ice extent
seems unlikely to cause widespread mortality through disruption of the
adult molt, or increased energetic costs for pups developing their
foraging capabilities. Rather, the overall strength of the impacts is
likely a function of the frequency of years in which they occur, and
the proportion of the population's range over which they occur. Also,
the effects on different age classes might be expected to be
correlated, though not always in concert, because they involve ice
characteristics at different times in the breeding molting period; low
ice extent during breeding may not always be accompanied by early
melting, and vice versa. As above, in the assessment of impacts on
reproduction, we conclude that the anticipated slight increase in
frequency of years with low ice extent in May and June is likely to
have some impact on survival rates.
The extent to which ribbon seals will adapt to more frequent years
with early ice melt by shifting the timing of reproduction and molting
is unknown. Peak whelping dates of harbor seals at Tugidak Island,
Alaska were 9 14 days earlier in 1964 and in the mid 1990s than in the
late 1970s. The changes were unlikely to be caused by shifts in the age
structure coupled with age specific differences in timing of
reproduction, and therefore may have been a response to changes in
environmental conditions. There are many examples in the scientific
literature of shifts in the timing of reproduction by pinnipeds
[[Page 79826]]
and terrestrial mammals in response to body condition and food
availability. In most of these cases, sub optimal conditions led to
later reproduction, which would not likely be beneficial to ribbon
seals as a phenotypic response to earlier spring ice melt. Over the
longer term (i.e. beyond the foreseeable future) a shift to an earlier
mean melt date may provide selection pressure for an evolutionary
response over many generations toward earlier reproduction.
Several factors are noteworthy for their potential to mitigate the
impacts on ribbon seals from predicted future sea ice scenarios. First,
adult ribbon seals may be less constrained to a specific geographic
area or region of the ice pack once breeding is complete, around the
onset of the adult molt. They may therefore be capable of considerable
shifts in distribution to ensure contact with suitable ice through the
molt period, especially in the Bering Sea where there is access through
the Bering Strait to the Chukchi Sea, in which ice persists more
frequently in June. Second, the models on which we based our assessment
of future ice conditions used a spatial resolution (~1[deg] of
latitude) that is much coarser than the scale at which ribbon seals are
likely to interact with fields of sea ice. Model scenarios, and the
remote sensed ice data that have been used to fit and tune the models,
may depict zero ice in areas where ribbon seals remain capable of
finding suitable ice. For example, in June 2008 the NOAA ship Oscar
Dyson encountered a field of ice with numerous ribbon and spotted seals
(Phoca largha) at 60[deg]N near St. Matthew Island, an area where no
ice was visible on the relatively high resolution (12.5 km) satellite
images of sea ice for that day. And third, the age of maturation for
females has been very low and pregnancy rates have been high in the
recent past (Section 2.7, Vital Parameters, of the Status Review),
implying that foraging conditions have been favorable, a scenario more
likely to reflect population growth rather than equilibrium; if so,
there may be some capacity to withstand a reduction in vital rates
without incurring an actual population decline.
In summary, more frequent future years of reduced spring ice extent
or ice quality could result in reduced vital rates of ribbon seal
reproduction and survival. These potential impacts are premised on the
assumption of a population at equilibrium with conditions in the recent
(cooler) past and the related possibility that changes such as
displacement of breeding locations or reduced availability of preferred
ice types will have some energetic costs that will ultimately be
reflected in vital rates. In the absence of relevant data, it is not
feasible to state the quantitative magnitude of the anticipated
impacts. Considering both the potential impacts and the factors
potentially conferring resilience, the BRT concluded that the net
impacts will be slight but chronic and likely to cause a gradual
decline in the ribbon seal population, but such decline is of
insufficient magnitude to place it in danger of extinction throughout
all or a significant portion of its range, now or within the
foreseeable future.
In light of the recent decision to list the polar bear as
threatened under the ESA, we note that the nature of ribbon seals'
relationship to sea ice is different from that of polar bears in
several significant respects. Ribbon seals' strong association with sea
ice occurs in sub Arctic seas, whereas polar bears are distributed
throughout most ice covered seas of the Northern Hemisphere, and
particularly in the Arctic Ocean. The seasonal contrast in the two
species' relationships with sea ice is also important. Ribbon seals use
annually formed sea ice for reproduction and molting in the spring, but
are largely unassociated with sea ice during summer, autumn, and early
winter, whereas most polar bears remain on the sea ice year round or
spend only short periods of time on land. Most polar bears rely on the
persistence of sea ice over productive continental shelf waters, where
they have both access to food (primarily ringed seals, Phoca hispida)
within the sea ice habitat and proximity to terrestrial denning areas.
Thus, the recent severe decline in the extent of summer sea ice,
particularly multi year ice, of the Arctic Ocean was a primary factor
in the conclusion that the polar bear should be considered threatened.
The further retreat of the summer sea ice into the Arctic polar basin
will force polar bears into increasingly marginal sea ice habitat over
relatively unproductive polar basin waters, or into terrestrial areas
lacking preferred prey and associated with increased competition and
human interactions. The increasing separation between the summer ice
edge and terrestrial denning areas will also subject polar bears to
increased open water swimming and risk of drowning. Ribbon seals, on
the other hand, are anticipated to experience little or no direct
effects from the further retreat of summer sea ice in the Arctic polar
basin, as they are primarily a pelagic, sub Arctic species during the
summer months.
Ocean acidification, a result of increased carbon dioxide in the
atmosphere, may impact ribbon seal survival and recruitment through
disruption of trophic regimes that are dependent on calcifying
organisms. The nature and timing of such impacts are, however,
extremely uncertain. Because of ribbon seals' apparent dietary
flexibility (Section 2.8 of the status review, Feeding Habits) and
because the major effects expected as a result of ocean acidification
may not appear until the latter half of this century, this threat is of
less immediate concern than the direct effects of sea ice degradation.
Further details on ocean acidification can be found in Section
4.3.1.1.4.2 of the status review.
Changes in ribbon seal prey, anticipated in response to habitat
changes resulting from ocean warming and loss of sea ice, have the
potential for negative impacts, but these impacts are not well
understood. Some changes already documented in the Bering Sea and the
North Atlantic Ocean are of a nature that could be ameliorative or
beneficial to ribbon seals. For example, several fish species,
including walleye pollock (Theragra chalcogramma), a common ribbon seal
prey, have shown northward distribution shifts and increased
recruitment in response to warming, at least initially. These ecosystem
responses may have very long lags as they propagate through trophic
webs. The apparent flexibility in ribbon seal foraging locations and
habits may make these threats of lower concern than more direct impacts
from changes in sea ice.
The above analyses of the threats associated with impacts of global
warming on ribbon seal habitat, to the extent that they may pose risks
to ribbon seals, were presumed 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 the species,
inasmuch as the finer scale spatial distribution of these threats is
not currently well understood. The analysis did not indicate that any
of these threats place the species in danger of extinction, now or in
the foreseeable future, in a significant portion of its range or its
entire range. More detailed information on the present or threatened
destruction, modification, or curtailment of ribbon seals' habitat or
range can be found in Section 4.3.1 of the status review.
Over-Utilization for Commercial, Subsistence, Recreational, Scientific,
or Educational Purposes
Recreational, scientific, and educational utilization of ribbon
seals is currently at very low levels and is not
[[Page 79827]]
projected to increase to significant threat levels in the foreseeable
future. Commercial harvests by Russian sealers have at times been high
enough to cause significant reductions in abundance and catch-per unit
effort. The population apparently rebounded from a period of high
harvest in the 1960s. Substantial but lower numbers were harvested for
a few years in the early 1990s. Although Russian government quotas were
recently put in place that would allow large harvests (~18,000
annually), the actual takes are low because of poor economic viability.
There is some effort in Russia to develop new uses and markets for seal
products, but unless this effort is successful, the harvest is unlikely
to increase in the near future. Subsistence harvest levels have been
low historically, but could potentially increase in the future if
ribbon seals are forced to use a reduced and more northerly ice field,
which could put them in closer proximity to Alaska Native communities
near the Bering Strait. Changes in subsistence or commercial takes
cannot be predicted with any certainty at this time. There is no
indication that illegal harvests are occurring.
Diseases, Parasites, & Predation
A variety of pathogens (or antibodies), diseases, helminthes,
cestodes, and nematodes have been found in ribbon seals. The prevalence
of these agents is not unusual among seals, but the population impact
is unknown. There may be an increased risk of outbreaks of novel
pathogens or parasites as climate related shifts in species
distributions lead to new modes of transmission. There is little or no
direct evidence of significant predation on ribbon seals, and they are
not thought to be a primary prey of any predators. Polar bears and
killer whales may be the most likely opportunistic predators in the
current sea ice regime, but walruses could pose a potentially greater
risk if reduced sea ice conditions force these pagophilic (ice-loving)
species into closer proximity in the future.
Inadequacy of Existing Regulatory Mechanisms
There is little evidence that the inadequacy of existing regulatory
mechanisms currently poses a threat to ribbon seals throughout all or a
significant portion of their range. However, there are no known
regulatory mechanisms that effectively address global reductions in sea
ice habitat at this time. Also, it is unclear what regulatory
mechanisms are in place to ensure that potential commercial harvests in
Russia are conducted in a sustainable fashion.
Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Although some pollutants are elevated in ribbon seals, there is no
conspicuous evidence of toxicity or other significant impacts to the
species throughout all or a significant portion of its range. Continued
and expanded monitoring would be prudent to document any trends in the
contaminants of greatest concern.
Oil and gas exploration and development activities may include
artificial island construction, drilling operations, pipeline
construction, seismic surveys, and vessel and aircraft operations. The
main issues for evaluating the impacts of exploration and development
activities on ribbon seals are the effects of noise, disturbance, and
potential oil spills produced from these activities. Any negative
effects on ribbon seals from noise and disturbance associated with
development activities are likely to be minor and localized. Ribbon
seals are also highly dispersed during the summer, open water season,
so the rate of interactions with seismic surveys would likely be low,
and, in any case, seals have not been shown to be significantly
impacted by oil and gas seismic surveys. The threat posed to ribbon
seals by oil spills will increase if offshore oil and gas development
and shipping activities increase across their range as predicted. The
potential impacts would be greatest during April June when the seals
are relatively aggregated, and substantially lower during the remainder
of the year when they are dispersed in the open water throughout the
North Pacific Ocean, Sea of Okhotsk, and Bering and Chukchi Seas.
Estimates from observed bycatch in commercial fisheries indicate
that less than 200 ribbon seals per year are taken, though mortalities
are certainly under reported in some fisheries. However, this level of
estimated bycatch of ribbon seals represents less than 0.1% of their
estimated population. Because there is little or no fishery activity
near aggregations of ribbon seals when they are associated with ice,
and they are highly dispersed during the remainder of the year, bycatch
is unlikely to be a significant threat to ribbon seal populations. For
the same reason, competition from fisheries that reduce local abundance
of ribbon seal prey is unlikely to be significant. Broad scale
reduction in a commercially fished, primary prey species could have a
significant impact, but the large groundfish fisheries in Alaskan
waters are managed to prevent depletion of the stocks.
The extraordinary reduction in Arctic sea ice that has occurred in
recent years has renewed interest in trans Arctic navigation routes
connecting the Atlantic and Pacific Oceans via the Northwest Passage
and the Northern Sea Route. The Chukchi Sea and Bering Strait would be
the most likely areas for increased exposure of pelagic ribbon seals to
ship traffic, because of the geographic constriction and the seasonal
migration of part of the ribbon seal population around the beginning
and end of the ice-free season. However, there is currently little or
no information on direct impacts from shipping on seals in open water.
Ribbon seals hauled out on sea ice may also be at risk from increased
ship traffic, but likely only during spring and early summer, and then
only by ice reinforced ships. Assessing risk from increases in shipping
and transportation is difficult because projections about future ship
trends within the ribbon seal's range are currently unavailable.
Several of the threats considered in this section were associated
with specific regions or times of year when ribbon seal distribution is
restricted, such as increased ship traffic in the Bering Strait region
or oil and gas activities during the ribbon seal breeding and molting
seasons. If such threats were to occur and cause a high rate of
mortality or forgone reproduction, the species could be considered
threatened or endangered in a significant portion of its range.
However, none of the threats considered here is presently considered to
be both sufficiently likely to occur and sufficiently high in impact,
alone or cumulatively, to raise concern about them posing a risk of
ribbon seal extinction or becoming endangered throughout a significant
portion of its range.
Conservation Efforts
When considering the listing of a species, section 4(b)(1)(A) of
the ESA requires consideration of efforts by any state, foreign nation,
or political subdivision of a state or foreign nation to protect the
species. Such efforts would include measures by Native American tribes
and organizations, local governments, and private organizations. Also,
Federal, tribal, state, and foreign recovery actions (16 U.S.C.
1533(f)), and Federal consultation requirements (16 U.S.C. 1536)
constitute conservation measures. On March 28, 2003, NMFS and the U.S.
Fish and Wildlife Service
[[Page 79828]]
(USFWS) published the final Policy for Evaluating Conservation Efforts
(PECE)(68 FR 15100). The PECE provides guidance on evaluating current
protective efforts identified in conservation agreements, conservation
plans, management plans, or similar documents (developed by Federal
agencies, state and local governments, tribal governments, businesses,
organizations, and individuals) that have not yet been implemented, or
that have been implemented but have not yet demonstrated effectiveness.
The PECE establishes two basic criteria for evaluating current
conservation efforts: (1) the certainty that the conservation efforts
will be implemented, and (2) the certainty that the efforts will be
effective. The PECE provides specific factors under these two basic
criteria that direct the analysis of existing conservation efforts.
The PECE identifies a number of factors to consider when evaluating
the certainty an effort will be implemented. These include whether: the
necessary resources (e.g., funding and staffing) are available; the
necessary agreements have been formalized such that the required
authority and regulatory mechanisms are in place; there is a schedule
for completion and evaluation of the stated objectives; and (for
voluntary efforts) the necessary incentives are in place to ensure
adequate participation. The evaluation of the certainty of an effort's
effectiveness is made on the basis of whether the effort or plan: (1)
establishes specific conservation objectives; (2) identifies the
necessary steps to reduce threats or factors for decline; (3) includes
quantifiable performance measures for the monitoring of compliance and
effectiveness; (4) incorporates the principles of adaptive management;
and (5) is likely to improve the species' viability at the time of the
listing determination.
The PECE identifies several important stipulations. Satisfaction of
the criteria for implementation and effectiveness establishes a given
conservation effort as a candidate for consideration, but does not mean
that the effort will ultimately change the risk assessment. The PECE
stresses that, just as listing determinations must be based on the
viability of the species at the time of review, they must also be based
on the state of protective efforts at the time of the listing
determination. There are circumstances where threats are so imminent,
widespread, and/or complex that it may be impossible for any agreement
or plan to include sufficient efforts to result in a determination that
listing is not warranted.
At this time, we are not aware of any formalized conservation
efforts for ribbon seals that have yet to be implemented, or which have
recently been implemented, but have yet to show their effectiveness in
removing threats to the species. NMFS co-manages ribbon seals with the
Ice Seal Committee (ISC), which is an Alaska Native Organization
dedicated to conserving seal populations, habitat, and hunting in order
to help preserve native cultures and traditions. The ISC co-manages ice
seals with NMFS by monitoring subsistence harvest and cooperating on
needed research and education programs pertaining to ice seals. Our
National Marine Mammal Lab is engaged in an active research program for
ribbon seals. The new information from research will be used to enhance
our understanding of the risk factors affecting ribbon seals, thereby
improving our ability to develop effective management measures for the
species.
ESA section 4(b)(1)(B) requires us to give consideration to species
which have been designated as requiring protection from unrestricted
commerce by any foreign nation, or pursuant to any international
agreement; or identified as in danger of extinction, or likely to
become so within the foreseeable future, by any state agency or any
agency of a foreign nation that is responsible for the conservation of
the species. We are not aware of any such special protections or
designations, or of any conservation efforts undertaken by foreign
nations specifically to protect ribbon seals. Ribbon seals are not
afforded any protective measures or special status via the Convention
for the International Trade in Endangered Species or the International
Union for Conservation of Nature.
In consideration of all of the threats and potential threats
identified above, the assessment of the risks posed by those threats,
the possible cumulative impacts, and the uncertainty associated with
all of these, we draw the following conclusions: (1) Ribbon seals are
not in current danger of extinction throughout all or a significant
portion of their range; (2) the abundance of the ribbon seal population
is likely to decline gradually for the foreseeable future, primarily
from slight but chronic impacts on reproduction and survival caused by
reduced frequency of years with sea ice of suitable extent, quality,
and duration of persistence; (3) despite the expectation of a gradual
decline, ribbon seals are not likely to become an endangered species
within the foreseeable future throughout all or a significant portion
of their range.
We have reviewed the status of the ribbon seal, considering the
best scientific and commercial data available. We have given
consideration to conservation efforts and special designations for
ribbon seals by states and foreign nations. Consideration of the ESA
section 4(a)(1) factors in the context of the biological status of the
species indicates that the species is not in danger of extinction
throughout all or a significant portion of its range, nor is it likely
to become so in the foreseeable future. We believe that the ribbon seal
does not meet the ESA definition of an endangered or threatened
species; therefore, the listing of ribbon seals under the ESA is not
warranted at this time. However, we will continue to monitor the status
of the ribbon seal. If conditions change in the future, we will re-
evaluate the status of this species to determine whether it should be
listed as threatened or endangered under the ESA. Because of the
remaining uncertainties regarding the effects of climate change, sea
ice cover, and potential Russian harvests, we will add the ribbon seal
to our Species of Concern list (http://www.nmfs.noaa.gov/pr/species/concern/#list; See 69 FR 19975, April 15, 2004 for description of
program). This will serve to (1) increase public awareness about the
species; (2) further identify data deficiencies and uncertainties in
the species' status and the threats it faces; (3) and stimulate
cooperative research efforts to obtain the information necessary to
evaluate the species' status and threats. As resources permit, we will
conduct further studies of ribbon seal abundance and status. We will
evaluate results of these and any other studies that may be conducted
and undertake a new status review, if warranted.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: December 22, 2008.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
[FR Doc. E8-31023 Filed 12-29-08; 8:45 am]
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