Marine Mammal Protection Act; Stock Assessment Reports for Two Stocks of Polar Bears, 33337-33343 [2021-13227]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 119 (Thursday, June 24, 2021)]
[Notices]
[Pages 33337-33343]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13227]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[FWS-R7-ES-2018-N051; FXES111607MPB01-189-FF07CAMM00]


Marine Mammal Protection Act; Stock Assessment Reports for Two 
Stocks of Polar Bears

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of availability; response to comments.

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SUMMARY: In accordance with the Marine Mammal Protection Act of 1972, 
as amended, we, the U.S. Fish and Wildlife Service, after consideration 
of comments received from the public, have revised marine mammal stock 
assessment reports for each of the two polar bear stocks in Alaska. We 
now make the final revised stock assessment reports for the Southern 
Beaufort Sea polar bear stock and the Chukchi/Bering Seas polar bear 
stock available to the public.

ADDRESSES: Document Availability: You may obtain a copy of the Southern 
Beaufort Sea polar bear and Chukchi/Bering Seas polar bear stock 
assessment reports by any one of the following methods:
     Internet: https://www.fws.gov/alaska/pages/marine-mammals/polar-bear (for both polar bear stocks).
     Write to or call (during normal business hours from 8 a.m. 
to 4:30 p.m., Monday through Friday) Dr. Patrick Lemons, Chief, U.S. 
Fish and Wildlife Service, Marine Mammals Management Office, 1011 East 
Tudor Road, MS-341 Anchorage, Alaska 99503; telephone: (800) 362-5148.

FOR FURTHER INFORMATION CONTACT: Dr. Patrick Lemons, Marine Mammals 
Management Office by telephone (800) 362-5148 or by email 
([email protected]). Persons who use a telecommunications device 
for the deaf (TDD) may call the Federal Relay Service at (800) 877-
8339.

SUPPLEMENTARY INFORMATION: We announce the availability of the final 
revised stock assessment reports (SARs) for two stocks of polar bears 
(Ursus maritimus).

Background

    Under the Marine Mammal Protection Act (MMPA; 16 U.S.C. 1361 et 
seq.) and its implementing regulations in the Code of Federal 
Regulations (CFR) at 50 CFR part 18, the U.S. Fish and Wildlife Service 
(Service) regulates the taking; import; and, under certain conditions, 
possession; transportation; purchasing; selling; and offering for sale, 
purchase, or export, of marine mammals. One of the goals of the MMPA is 
to ensure that stocks of marine mammals occurring in waters under U.S. 
jurisdiction do not experience a level of human-caused mortality and 
serious injury that is likely to cause the stock to be reduced below 
its optimum sustainable population level (OSP). The OSP is defined 
under the MMPA as ``the number of animals which will result in the 
maximum productivity of the population or the species, keeping in mind 
the carrying capacity of the habitat and the health of the ecosystem of 
which they form a constituent element'' (16 U.S.C. 1362(9)).
    To help accomplish the goal of maintaining marine mammal stocks at 
their OSPs, section 117 of the MMPA requires the Service and the 
National Marine Fisheries Service (NMFS) to prepare a SAR for each 
marine mammal stock that occurs in waters under U.S. jurisdiction. A 
SAR must be based on the best scientific information available; 
therefore, we prepare it in consultation with an independent Scientific 
Review Group (SRG) established under section 117(d) of the MMPA. Each 
SAR must include:
    1. A description of the stock and its geographic range;
    2. A minimum population estimate, current and maximum net 
productivity rate, and current population trend;
    3. An estimate of the annual human-caused mortality and serious 
injury by source and, for a strategic stock, other factors that may be 
causing a decline or impeding recovery of the stock;
    4. A description of commercial fishery interactions;
    5. A categorization of the status of the stock; and
    6. An estimate of the potential biological removal (PBR) level.
    The MMPA defines the PBR as ``the maximum number of animals, not 
including natural mortalities, that may be removed from a marine mammal 
stock while allowing that stock to reach or maintain its OSP'' (16 
U.S.C. 1362(20)). The PBR is the product of the minimum population 
estimate of the stock (Nmin); one-half the maximum 
theoretical or estimated net productivity rate of the stock at a small 
population size (Rmax); and a recovery factor 
(Fr) of between 0.1 and 1.0, which is intended to compensate 
for uncertainty and unknown estimation errors. This can be written as:

PBR = (Nmin)(\1/2\ of the Rmax)(Fr).

    Section 117 of the MMPA also requires the Service and the NMFS to 
review the SARs (a) at least annually for

[[Page 33338]]

stocks that are specified as strategic stocks, (b) at least annually 
for stocks for which significant new information is available, and (c) 
at least once every 3 years for all other stocks. If our review of the 
status of a stock indicates that it has changed or may be more 
accurately determined, then the SAR must be revised accordingly.
    A strategic stock is defined in the MMPA as a marine mammal stock 
``(A) for which the level of direct human-caused mortality exceeds the 
PBR level; (B) which, based on the best available scientific 
information, is declining and is likely to be listed as a threatened 
species under the Endangered Species Act of 1973, [as amended] (16 
U.S.C. 1531 et seq.) [ESA], within the foreseeable future; or (C) which 
is listed as a threatened or endangered species under the ESA, or is 
designated as depleted under the MMPA'' (16 U.S.C. 1362(19)).

Stock Assessment Report History for the Two Polar Bear Stocks

    Both polar bear SARs were last revised in January 2010. Because the 
polar bear is listed as a threatened species under the ESA, both the 
Southern Beaufort Sea and the Chukchi/Bering Seas polar bear stocks are 
considered strategic. The Service therefore considered all available 
new information on these stocks in 2011, 2012, and 2013, and determined 
that no new information was available that indicated the status of the 
stocks had changed or could be more accurately determined. However, as 
new information became available in 2014, the Service initiated 
revision of the SARs, and once completed, presented them for review to 
the SRG. Subsequent to that review, the Service published a notice in 
the Federal Register informing the public of the availability of these 
draft revised SARs and seeking public comment (82 FR 28526; June 22, 
2017). These final revised SARs incorporate the comments and 
suggestions provided to the Service by the SRG and the public, as 
appropriate.

Summary of Revised Stock Assessment Reports for the Two Polar Bear 
Stocks in Alaska

    The following table summarizes some of the information contained in 
the revised SARs for the Southern Beaufort Sea polar bear and the 
Chukchi/Bering Seas polar bear stocks, which includes each stock's 
Nmin, Rmax, Fr, PBR, annual estimated 
human-caused mortality and serious injury, and status.

Summary--Final Revised Stock Assessment Reports for the Southern Beaufort Sea Polar Bear and Chukchi/Bering Seas
                                                Polar Bear Stocks
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                                                                       Annual estimated human-
        Polar bear stock           Nmin      Rmax       Fr      PBR     caused mortality and      Stock status
                                                                           serious injury
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Southern Beaufort Sea..........       782     0.075      0.5       14  Annual estimated        Strategic.
                                                                        removals for each
                                                                        stock are provided in
                                                                        the SARs.
Chukchi/Bering Seas............     2,000    0.0603      0.5       30                          Strategic.
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Response to Public Comments

    We received comments on the draft revised SARs from the Marine 
Mammal Commission (Commission), Department of Wildlife Management, 
North Slope Borough, Utqia[gdot]vik, Alaska, BP Exploration (Alaska), 
Inc., and the Center for Biological Diversity. We present substantive 
issues raised in those comments that are pertinent to the SARs, edited 
for brevity, along with our responses below.

General Public Comments That Apply to Both SARs

    1. The Service should undertake a more extensive, finer scale 
analysis of genetic differences between the Chukchi/Bearing Seas (CBS) 
and Southern Beaufort Sea (SBS) stocks to delineate further the extent 
of stock discreteness.
    Response: Genetic differentiation between the two stocks is one 
metric to consider, but we believe sufficient data exist from other 
metrics (behavioral, movement, demographic) to support the current 
differentiation of the stocks. We will continue to review new 
information as it becomes available and reassess their discreteness. 
Additionally, the genetic work that has been done (and is cited in the 
current SARs) suggests that there is little genetic variation between 
the two stocks.
    2. The section on the distribution of the CBS and SBS stocks of 
polar bears should be expanded to discuss the uncertainty over where to 
draw the stock boundaries between them and the efforts that are being 
taken to resolve these questions.
    Response: Although the MMPA does not require the Service to 
describe stock boundaries but rather stock ranges, we added text to 
both documents indicating there is uncertainty associated with the 
current boundary.
    3. Figure 3 in both SARs should be revised to include alternative 
harvest estimates using Icy Cape as one possible stock boundary and 
Point Barrow as the other given the uncertainty over where to draw the 
boundary between the CBS and SBS stocks.
    Response: For the purposes of these SARs, the Service continues to 
accept the boundaries identified by the Polar Bear Specialist Group 
(PBSG). Should new information become available to better define these 
boundaries in the future, we will revise the SARs to reflect that new 
information.
    4. The Service should revise the genetics section of both SARs to 
include a stronger statement about the role genetics plays in the 
Service's decision to manage stocks separately.
    Response: Although the statute does not require a discussion of 
genetics in the SARs, we included information on research that shows 
the stocks appear to be genetically similar. However, we explicitly 
state that other factors (e.g., behavior) warrant the stocks being 
managed separately. The Service has determined that a stronger 
statement is not necessary.
    5. In the `current population trend' sections of both SARs the 
Service should explain why it has determined removals for subsistence 
during the 20th century were low enough to allow the populations to 
remain near carrying capacity.
    Response: The SARs do not state that subsistence during the 20th 
century was low enough to allow populations to remain near carrying 
capacity. Rather, it states that this is our belief for the period 
prior to the 20th century when subsistence harvest would have been the 
primary source of anthropogenic mortality.
    6. The ``climate change'' section of each report discusses the 
listing of ringed and bearded seals by the NMFS under the ESA. The 
Service notes that a district court ruling vacating the bearded seal 
listing was overturned on appeal, so that the listing is again in 
force. The Service should also note that the appeal of the ruling 
vacating the ringed seal listing is still pending.

[[Page 33339]]

    Response: The U.S. Supreme Court denied the petition for review of 
the decision and, therefore, the listings stand. We have removed these 
statements from the SARs.
    7. The Service should improve its review of the status of the 
stocks on an annual basis.
    Response: SARs are thoroughly vetted and accurately reflect the 
best scientific information available. The Service meets its statutory 
requirements of reviewing both polar bear stock assessments on an 
annual basis and, if appropriate, revises the current SARs. The Service 
then submits these draft revisions first to the SRG, noting to the SRG 
that they are preliminary documents pending complete Service review, 
and then for public comment. The Service also updates the SRG on any 
new information and ongoing studies during the SRG's annual meeting. We 
appreciate the concern over the time it takes for both of these reviews 
but balance that concern with the need to ensure our SARs contain the 
best available scientific information and are subject to public notice 
and comment process.
    8. The SARs must clearly state that anthropogenic climate change is 
the primary threat to the SBS and CBS stocks and must include key 
scientific findings documenting the negative effects that climate 
change is having on these populations.
    Response: There are currently no studies that show negative 
population-level impacts of sea ice loss for polar bears in the CBS 
stock. However, there are behavioral and distributional changes 
occurring as a result of sea ice loss, and we currently cite those 
studies that show such effects to the CBS stock (e.g., Rode et al. 
2015a, Wilson et al. 2016). We also document studies that show the 
negative population-level effects that the SBS stock are experiencing 
as a result of sea ice loss. We have added a citation to Atwood et al. 
(2016) to further clarify that climate change has been identified as 
the primary threat to polar bears.
    9. The Service should emphasize that bears in both populations are 
spending less time in their preferred shallow water sea-ice habitats as 
these habitats diminish and more time in marginal habitats on shore and 
on sea ice off the continental shelf. The following studies should be 
cited: Gleason and Rode (2009), Cherry et al. (2013), and Ware et al. 
(2017).
    Response: We added a reference to the Gleason and Rode (2009) study 
to make this point for the SBS SAR. The Ware et. al., study (2017) does 
not provide information that significantly changes our understanding of 
how bears' use of sea ice changes as it relates to sea ice loss, nor 
does it provide information that indicates the status of the species 
has changed or can be more accurately determined. The study by Cherry 
et al. (2013) is in reference to bears in Hudson Bay, so is not 
relevant for these SARs. We also cite Rode et al. (2015) in the CBS SAR 
to document increased land use by those bears, and Wilson et al. (2016) 
to highlight the reduction in `optimal' summer sea ice habitat in the 
Chukchi Sea.
    10. The Service should include new findings that provide further 
evidence for an increase in land-based denning in response to climate 
change: Olson et al. (2017).
    Response: The study by Olson et al. (2017) does not include 
information that substantially alters our understanding of increased 
land-based use, which is confirmed in Fishbach et al. (2007). Nor does 
it provide information that indicates the status of the species has 
changed or can be more accurately determined.
    11. In describing the different responses of the CBS and SBS stocks 
to sea ice loss, the SAR should report the findings of Ware et al. 
(2017).
    Response: As stated previously, the study by Ware et al. (2017) 
does not provide information that substantially alters our 
understanding of either population's status nor does it provide 
information that indicates the status of the species has changed or can 
be more accurately determined. The study by Ware et al. (2017) confirms 
our understanding of the different responses of the two stocks, 
information that is already discussed in the SAR.
    12. The Service should include the following citations for 
increasing energetic costs associated with sea ice changes: Durner et 
al. (2017), Ware et al. (2017).
    Response: As stated previously, these studies do not provide 
information that substantially alters our understanding of either 
population's status and do not provide information that indicates the 
status of the species has changed or can be more accurately determined. 
Further, these studies indicating energetic costs associated with sea 
ice loss confirm information already considered in this SAR.
    13. The Service should clearly and finally delineate the CBS/SBS 
boundary line.
    Response: We do not believe the SARs are the appropriate document 
in which to discuss delineation of the boundary line between these two 
stocks. We have described the geographic range of these stocks as 
required by the MMPA.
    14. The SARs must include important new information on the threats 
from oil and gas development including the April 2017 Executive Order 
attempting to lift the permanent ban on offshore drilling in the U.S. 
Arctic, and the Bureau of Ocean Energy Management proposal to approve 
the offshore Liberty drilling project in SBS polar bear habitat.
    Response: On January 20, 2021, the President issued Executive Order 
13990, which, amongst other things, revoked Executive Order 13795. 
Considering this action, the Service believes the SARs adequately 
address any potential threats from oil and gas development.
    15. The SARs should acknowledge there are currently no effective 
means of cleaning up an oil spill in Arctic waters.
    Response: Section 117(a)(3) requires the agency provide information 
on other factors that may cause a decline or impede recovery of a 
strategic stock. An oil spill in the Arctic could have negative impacts 
on these stocks, particularly if there are no (or limited) means of 
cleaning the spill. Therefore, we have included a statement to this 
effect in the revised documents.
    16. The Service needs to categorize each stock's status relative to 
OSP.
    Response: Section 117(a) states the draft SAR shall categorize the 
status of the stock as one that either has a level of human-caused 
mortality and serious injury that is not likely to cause the stock to 
be reduced below its OSP or is a strategic stock. The Service has 
categorized the status of each stock as strategic.
    17. The SARs must acknowledge that harvest of both populations 
exceeds PBR and may cause the stocks to be reduced below their optimal 
sustainable population, which is prohibited by the MMPA.
    Response: In meeting our statutory requirements under the MMPA 
Section 117, this stock assessment report contains an estimate of the 
potential biological removal level, describing the information used to 
calculate the estimate. We have determined that the SARs adequately 
describe the scope and extent of polar bear harvest in both stocks as 
presented.
    18. The SARs should include and discuss studies that forecast the 
likely extirpation of both polar bear stocks within this century: 
Amstrup et al. (2010), Atwood et al. (2016), Regehr et al. (2016).
    Response: We have further reviewed these studies and note they 
conclude the stocks have a high probability of becoming greatly 
reduced. Section 117(a)(3) requires the agency provide information on 
other factors that may

[[Page 33340]]

impede recovery of a strategic stock and, therefore, we added this 
point to the climate change section of each SAR.
    19. Speculation on the long-term status of each polar bear stock 
should be organized within a discrete section that is appropriately 
described as such.
    Response: We believe this information is appropriately contained 
within their current sections and that sufficient information is 
provided to allow readers to assess the level of confidence in the 
currently available science.
    20. The Service has provided inconsistent messages about the 
boundaries of both the CBS and SBS polar bears, which makes it 
difficult for subsistence hunters, subsistence communities, the public, 
and decisionmakers to adequately understand polar bear biology or 
management or the position of the Service. Clarity is needed on both 
boundaries.
    Response: Section 117 requires that the agency describe the 
geographic range of the subject stocks, including any seasonal or 
temporal variations but it does not require a delineation of 
boundaries. These SARs are based on the geographic ranges as described 
in each document. While work is currently being conducted to update the 
biology associated with the geographic range of the CBS and SBS stocks, 
the description provided in these documents reflects the best available 
science for each stock.
    21. Each SAR should be clear about the factors associated with 
uncertainty in determining whether the polar bears in each region 
constitute a stock. Further, the Service should also describe in detail 
the implications (e.g., conservation, subsistence) of the current 
uncertainty and inconsistencies in stock boundary determination.
    Response: We have explicitly provided the factors that identify 
these stocks as being considered and managed separately. These two 
stocks are spatially segregated and each stock is made up of a group 
occurring ``in a common spatial arrangement,'' per the statutory 
definition. This separation is further supported by the different 
patterns in body condition and responses to sea ice loss. Although we 
acknowledge there is some confusion concerning the established 
boundaries between these stocks, we do not believe the SARs are the 
appropriate document in which to discuss issues associated with these 
uncertainties.
    22. The Service's information on contaminants is incomplete for 
both stocks and does not include more recent papers. Relevant missing 
literature includes: Dietz et al. (2015); Letcher et al. 2011 
(conference abstract); McKiney et al. (2011a, b); Nuijten et al. 
(2016); and Routti et al. (2011). SARs should be updated to include the 
above references.
    Response: We included additional information as appropriate in each 
SAR.
    23. More detail should be provided about which Traditional 
Ecological Knowledge stakeholders were consulted and how that 
information was used to inform SARs.
    Response: We added reference to the Voorhees et al. (2014) study in 
the CBS SAR and the Joint Secretariat study (2015) in the SBS SAR.
    24. The Service should clarify what is meant by `relatively 
discrete subpopulations' on page 1 of both SARs.
    Response: We removed the term ``relatively discrete'' as it does 
not add to the statement that there are 19 subpopulations.
    25. Contaminant samples were not collected in a random or 
systematic manner. The Service should explain how contaminant data are 
indicative of stock status versus a sampling artifact or a difference 
in prey species having different contaminant burdens and provide 
evidence on how samples were collected.
    Response: The studies cited found that contaminants vary between 
bears in the two stocks, providing evidence of spatial segregation or 
differences in space use between them.
    26. The Service should provide evidence of why CBS and SBS stocks 
should be separated given the weak genetic and movement data (i.e., 
overlap in distribution of tagged bears).
    Response: We disagree that there are weak movement data. In the 10+ 
years that the Service has been conducting polar bear capture work in 
the Chukchi Sea, only twice have bears been recaptured in the Chukchi 
Sea that were previously captured in the Beaufort Sea. Similarly, we 
are unaware of any bears captured in the Chukchi Sea being recaptured 
in the Beaufort Sea. Movement data from Global Positioning System (GPS) 
collars clearly shows bears captured in the Chukchi Sea move to the 
northwest and away from the Beaufort Sea as the ice retreats, with many 
summering on the Russian coast and none ever summering on the northern 
coast of Alaska. Conversely, polar bear movements of those captured in 
the Beaufort Sea show bears moving north and northeast as the ice 
retreats. Those bears that summer on shore do so primarily near 
Kaktovik, Alaska, and not the Russian coast. In addition to movement 
data, numerous studies have shown significant differences in how bears 
in the two stocks are responding to sea ice loss, with bears in the 
Beaufort Sea experiencing population declines, lower body conditions, 
and reduced reproductive performance than bears in the Chukchi Sea.
    27. More details are needed about how the location of tagged bears 
in the Chukchi and Beaufort Seas might influence the representativeness 
of tagged bears to the entire population.
    Response: We added additional information stating that it's unclear 
what role capture location plays in our estimate of the stock's 
distribution, but that bears captured south of Point Hope overlap the 
space use patterns of bears that were captured more widely in the early 
1990s.
    28. On page 5 (SBS SAR) and page 6 (CBS SAR) similar sentences are 
present that state ``polar bears are generally expected to experience 
nutritional stress as loss of sea ice continues . . . .'' How is this 
relevant to defining the stocks? Even if relevant, both stocks respond 
similarly, thereby contradicting the supposition that these are stocks. 
The paragraph with these statements is not relevant to stock definition 
or geographic range and should therefore be removed from this section.
    Response: We disagree. The statutory definition of a ``population 
stock'' or ``stock'' includes a group of marine mammals of the same 
species occurring ``in a common spatial arrangement,'' such as these 
two polar bears stocks. The information is relevant to describing these 
two stocks because, even though bears may respond similarly to changing 
sea ice conditions, it shows that they are spatially segregated. If 
there was no spatial segregation, then we would expect to see similar 
patterns in body condition and response to sea ice loss between the 
stocks. However, the opposite is true. We therefore believe information 
in these paragraphs remains relevant and important to report.

Comments Specific to the Chukchi/Bering Seas Stock Assessment

    29. The Service should revise the SAR for the CBS stock to conform 
to that guidance [Guidelines for Preparing Stock Assessment Reports 
published by the National Marine Fisheries Service (NMFS) in 2016] by 
indicating that the minimum population size is unknown. If the Service 
retains 2,000 bears as the estimate of minimum population size in the 
final report, the agency should include compelling evidence that the 
stock has not declined since the last survey. In addition, as explained 
in the guidelines, a minimum population estimate should be calculated 
to provide assurance that ``a stock of unknown status would achieve and 
be maintained within OSP with 95% probability.''

[[Page 33341]]

Consistent with that guidance, the Service should include an analysis 
of how its point estimate of 2,000 bears (which, in any event, appears 
to be an estimate of Nbest rather than Nmin) satisfies this directive 
and meets the requirement under section 3(27) of the MMPA that the 
minimum population estimate provide reasonable assurance that ``the 
stock size is equal to or greater than the estimate.''
    Response: The Service appreciates and supports the efforts of the 
NMFS in developing their Office of Protected Species Technical 
Memorandum and the 2016 Guidelines for Preparing Stock Assessment 
Reports. However, these NMFS guidelines have not been adopted by the 
Service, and, while we consider the information contained within them 
to the extent applicable, they are not binding on the Service. 
Nonetheless, as discussed in the SAR, the Service considers a minimum 
population estimate of 2,000 individuals (Aars et al. 2006) to be the 
best available scientific information we have at this time. In 
addition, recent studies have indicated that bears inhabiting the 
Chukchi Sea seem to be in good physical condition and may be 
experiencing population growth (Voorhees et al. 2014; Rode et al. 
2014). Therefore, we are reasonably assured that the CBS stock includes 
at least 2,000 bears.
    30. Revise the section that discusses the U.S.-Russia Bilateral 
Agreement to state that harvest limits set under the Agreement have yet 
to be implemented by the United States pending the establishment of 
needed management and enforcement structures.
    Response: We do not believe the comment accurately describes 
Service actions under the U.S.-Russia Bilateral Agreement. Although we 
do not believe the SAR is the appropriate document in which to discuss 
implementation of the harvest limits under the U.S.-Russia Bilateral 
Agreement, we have provided updates to the SAR to reflect recent 
actions by the Commission and the Service.
    31. The discussion of harvest in Russia is included in the section 
on ``other mortality'' in the draft CBS SAR, because it is considered 
illegal. However, according to Kochnev and Zdor (2014) most, if not 
all, of that harvest is for subsistence purposes. If this is the case, 
it would make more sense to move that discussion into the section on 
Native subsistence harvest. Also, rather than relying on a personal 
communication from Eduard Zdor as one of the sources for the 
information, the Service should cite the related publication, Kochnev 
and Zdor (2014), which is included in the ``citations'' section as 
Kochnev and Zdor (2015).
    Response: We included the citation of Kochnev and Zdor (2015) 
instead of the personal communications statement. However, we kept this 
information in the ``other mortality'' section because it is still 
unreported harvest and unclear how much is for subsistence or possibly 
other purposes.
    32. The Service should report total harvest mortality for the CBS 
stock, including both the United States and Russia. Thus report 32 
bears as the best estimate of direct harvest in Russia.
    Response: We agree and added text to the final SAR to reflect this 
information.
    33. The SAR should cite the following studies suggesting low cub 
production and reduced maternity denning: Ovsyanikov (2012), Ovsyanikov 
and Menyushina (2014).
    Response: We do cite Ovsyanikov (2012), which sufficiently makes 
the identified points.
    34. The CBS population estimate should be listed as `unknown' given 
that it is more than 8 years old, and PBR should be listed as 
`undetermined' as PBR cannot be calculated with an unknown minimum 
population size.
    Response: The population estimate of 2,000 is based on extrapolated 
den data, which we acknowledge is more than 10 years old. It was the 
best scientific information available for these calculations. The 
Service has been analyzing data on this stock, and we will revise our 
SARs, subsequent to that analysis, if appropriate.
    35. On page 9, in the last paragraph, the Service should insert `in 
Russia' after `illegal harvests.'
    Response: We have made this change.
    36. On page 10, in the top paragraph: Why is the information in 
Kochnev and Zdor (2015) not presented given that it represents the best 
available information?
    Response: This section discusses the historic views on overharvest 
in the early 2000s; therefore, the study by Kochnev and Zdor is not 
relevant. We do, however, discuss the results of Kochnev and Zdor in 
the subsequent discussion.
    37. On page 10, the last two paragraphs in the penultimate 
paragraph on the page, the Service cautions that the results of 
Ovsyanikov (2012) were based on an ``inconsistent study design among 
years and lack of quantitative analyses to understand the demographic 
ramifications of the observed recruitment indices.'' The Service then 
goes on to use those results to suggest there is an ``apparently lower 
reproduction on Wrangel Island.'' If Ovsyanikov's results are suspect, 
then they should not be used in the SAR. The following should be 
deleted from the final sentence on this page: ``apparently lower 
reproduction on Wrangel Island.''
    Response: We believe it is relevant to cite the study by Ovsyanikov 
but highlight for readers the reasons why the results might not be 
reliable. We also did not delete ``apparently lower reproduction on 
Wrangel Island'' because it is in reference to the decision making 
process of the PBSG, and that is one of the factors they cited in their 
decision to consider the population `data deficient.'
    38. The second complete sentence on page 13 is information from 
Kochnev and Zdor (2015), which provides subsistence removal estimates 
based on interview data. Reference to this paper and its information 
should be included in the SAR.
    Response: We agree and revised the SAR to reflect this information.
    39. On page 16, the last sentence of the paragraph before ``Status 
of Stock'' is information from Kochnev and Zdor (2015), which is 
criticized for reasons similar to those given for Ovsyanikov (2012).
    Response: As noted above, we revised the SAR to reflect both 
studies and discussed their limitations.
    40. On page 19, the last sentence of paragraph before ``Oil and Gas 
Extraction'', the interpretation of Wilson et al. (2016) is that 
population declines will occur as a result of lost ``preferred'' 
habitat. This statement is overreaching.
    Response: We changed ``continued loss is likely to lead to 
population declines . . .'' to ``continued loss could lead to 
population declines . . . .''

Comments Specific to the Southern Beaufort Sea Stock Assessment

    41. Commenter appreciates the transparency and acknowledgement that 
the SBS minimum population estimate is biased low because the western 
extent of the SBS stock range (west of Point Barrow) was not included 
in previous capture/recapture studies. It is likely that the minimum 
population estimate is higher than 782 bears listed on page 8 of the 
draft stock report, given that a portion of the SBS stock range is not 
reflected in prior studies.
    Response: We agree and recognize that the minimum population 
estimate may be higher. Thus, consistent with the statutory definition 
of ``minimum population estimate,'' the estimate provides reasonable 
assurance that the stock is equal to or greater than the estimate.
    42. In the Other Mortality subsection, the Service should strike 
the words, ``near industry facilities'' from the line

[[Page 33342]]

on page 13: ``In 2012, one adult female and her two-year old male cub 
were found dead on an island near industry facilities.'' Industry 
operators worked closely with Service Law Enforcement and the Marine 
Mammals Management Office after the discovery of these bears. There was 
no discovered source of rhodamine B or hazardous substance unsecured or 
available to wildlife at industry facilities. The bears were also 
discovered close to Cross Island (the base for local whaling 
activities), a U.S. Air Force short-range radar site, and local 
communities. There are also shipping and boating activities that occur 
throughout the Beaufort Sea that could have been a source. Please 
include all or none of these potential sources given that the cause of 
the polar bears' death remains unknown.
    Response: We made the suggested change.
    43. The U.S. Geological Survey (USGS) has collected population data 
on SBS bears through at least 2015; new data should be analyzed and 
presented as soon as possible.
    Response: The USGS was working to analyze those data at the time 
the SAR was being developed; the Service considers all information, 
including information from the USGS, when it is available to us.
    44. The Service should provide information on the map in Figure 2 
indicating whether overlap exists between the two stocks (Northern 
Beaufort Sea (NBS) and SBS) and showing its likely extent. In addition, 
the Service should provide available information on the range of the 
stocks. The Service should use the best available information when 
describing the range of the SBS stock regardless of whether or not it 
has been accepted by the PBSG.
    Response: We modified the figure to include information on the 
Northern Beaufort Sea stock.
    45. Harvest data from Canada should be included in Figure 3 of the 
Service's SAR.
    Response: Canada records and reports harvest data based on a 
hunting season that overlaps 2 calendar years. The U.S. portion of the 
harvest, which is provided in Figure 3, is reported based on annual 
harvest data. Therefore, rather than revise Figure 3, we have included 
their harvest information in the body of the SAR.
    46. A proposed Rmax of 7.5 percent for the SBS 
population is much too high and the rate should be revised to a more 
science-based and precautionary value.
    Response: As we describe in the SAR, under favorable conditions, 
the population was capable of increasing up to 7.5 percent. Although we 
also acknowledge that potential current and future effects could lead 
to lower realized growth rates, 7.5 percent provides the best estimate 
to date of Rmax.
    47. The Service should confirm the current quota of 70 bears under 
the agreement between the Inuvialuit of Canada and the Inupiat of 
Alaska (I-I Agreement).
    Response: We have corrected the text to reflect a quota of 56 
bears: 35 for the United States and 21 for Canada.
    48. The Service should include total harvest mortality for the SBS 
stock, including U.S. and Canada harvest.
    Response: We included data on recent harvest as reported by Canada, 
which reports harvest by season rather than on annual bases.
    49. The Service should explain the changes to the SBS boundary by 
Canada and explain how those changes affect the annual average 
mortalities of the SBS.
    Response: We determined that information in the distribution 
section adequately reflects the changes of the boundary and included 
text to clarify the number of bears currently being harvested in 
Canada.
    50. The Service should cite the following studies to show declines 
in the stock being related to sea ice loss: Bromaghin et al (2015); 
Rode et al. (2014); and Regehr et al. (2010).
    Response: Those studies are already cited making those points.
    51. The SAR states that bears in the SBS are expected to experience 
nutritional stress, but evidence indicates that it is already 
happening: Cherry et al. (2009) and Whiteman et al. (2015).
    Response: The SAR states that, in general, polar bears are expected 
to experience nutritional stress. The section then goes on to provide 
evidence that bears in the SBS stock are experiencing negative effects 
of ice loss (e.g., Rode et al. (2014)).
    52. The Service should include the Herreman and Peacock (2013) and 
Rogers et al. (2015) studies as evidence of increased vulnerability to 
conflicts with humans.
    Response: We did not add the citations suggested because they do 
not provide evidence of increased vulnerability of conflicts with 
humans. However, we have added an additional statement to this effect 
after citations that do support this contention (e.g., Schliebe et al. 
(2008), Atwood et al. (2015a)).
    53. The Service should cite Durner et al. (2011), Pagano et al. 
(2012), and Pilfold et al. (2017) as evidence of increased long-
distance swimming and mortality/physiological stress.
    Response: We agree and added the references and citations to the 
discussion on responses to changing sea ice conditions.
    54. The population estimate for the SBS stock is nearly 8 years 
old. If no new estimates are available in 2018, the Service should 
revise the SAR and indicate that the population estimate is unknown.
    Response: We acknowledge the concern raised by the comment; 
however, we believe the population estimate of 900 animals reflects the 
best scientific information available for this SAR. In addition, 
because of possible negative biases, this population estimate is based 
on a cautious interpretation of trends and estimates and, therefore, we 
are reasonably assured that the SBS stock includes at least 900 bears. 
We will continue to review, on an annual basis, the status of this SAR 
to determine whether a revision is warranted.
    55. Details on the distribution of terrestrial den sites (e.g., 
which barrier islands, how many sites, etc.) should be provided in 
tables and/or figures rather than abstracted statements like 
``Currently, the primary terrestrial denning areas for the SBS stock in 
Alaska occur on the barrier islands from Barrow to Kaktovik, and along 
coastal areas up to 25 miles inland, including the Arctic National 
Wildlife Refuge to Peard Bay, west of Barrow.''
    Response: It is not possible to give a specific description of 
where all dens of the stock are distributed given that not every single 
adult female in the population has a GPS collar. As written, the 
existing descriptions cover the known distribution of polar bear dens. 
Sufficient denning habitat exists across the North Slope, so depending 
on snow cover in any given year, which is itself variable, anywhere 
within the described area could be used for denning.
    56. There should be discussion in the first paragraph about the 
relevant management authority for the SBS stock, specifically add 1-2 
sentences about the I-I Polar Bear Commission that manages the quota 
for the taking of polar bears in the Beaufort Sea.
    Response: We determined that the SAR adequately informs the reader 
of this voluntary quota as written.
    57. On page 6, it should be emphasized that population estimates 
have been difficult to obtain because the fieldwork does not correspond 
to the stock boundaries.
    Response: We determined that the SAR adequately describes 
challenges associated with population estimates.

[[Page 33343]]

    58. Although information is presented from Bromaghin et al. (2015), 
more data on the SBS population have been collected that are not 
presented in the SAR. Those data represent the best available science/
information and, therefore, that information should be presented.
    Response: Those data represent raw data that had not yet been 
analyzed at the time this SAR was developed and, in their state, they 
provided no additional information on the population's size.
    59. The sentences on page 9 about harvest seem to conflict given 
their overlap in time.
    Response: We are unaware of a conflict in the material as 
presented.
    60. On page 9, in the first paragraph, it is unclear how reports 
from Russian scientists pertain to SBS polar bears. Explanation needed.
    Response: We agree and removed reference to Russian scientists and 
residents of coastal Russia from the document.
    61. On page 10, top paragraph, the phrase ``Based on all available 
data . . .'' is not accurate. Data were collected through 2015, and 
thus data should have been available from 2010 to 2014 to the PBSG. 
This sentence should be revised.
    Response: The statement is accurate as written. The PBSG made their 
determination based on the available analyses on the population. While 
additional data have been collected on the SBS stock by the USGS, they 
had not yet been analyzed at the time the SAR was developed and were 
therefore unavailable for the PBSG to consider.
    62. On page 15, the statement ``Polar bears are adapted to life in 
a sea ice environment'' is somewhat misleading. The southern 
populations of polar bears, such as those in Hudson Bay, Labrador, and 
the Bering Sea, use sea ice only when available, and turn to alternate 
terrestrial habitat in summer. A more factually correct statement might 
read, ``Polar bears are adapted to life on sea ice but show significant 
temporal use of terrestrial habitats as well.''
    Response: We disagree. A primary factor that separates grizzly 
bears and polar bears is the adaptation of polar bears to life on sea 
ice. While it is true that polar bears come on land when sea ice is 
unavailable, if they were to stay on land indefinitely, they would not 
survive because they require seals hunted on sea ice to survive.
    63. On page 18 there is an assertion, ``Oiled polar bears are 
unable to effectively thermoregulate, and may be poisoned by ingestion 
of oil during grooming or eating contaminated prey (St. Aubin 
(1990)).'' Polar bears are highly vulnerable to oil ingestion with 
subsequent fatality (Oritsland et al. (1981)). This section needs 
revision with appropriate literature sources.
    Response: We disagree as the appropriate and important impacts to 
polar bears are discussed in the SARs. We have, however, updated the 
document to cite [Oslash]ritsland et al. (1981).

References

    In accordance with section 117(b)(1) of the MMPA, we include in 
this notice a list of the sources of information or published reports 
upon which we based the revised SARs. The Service consulted technical 
reports, conference proceedings, refereed journal publications, and 
scientific studies prepared or issued by Federal agencies, non-
governmental organizations, and individuals with expertise in the 
fields of marine mammal biology and ecology, population dynamics, 
Alaska Native subsistence use of marine mammals, modeling, and 
commercial fishing technology and practices. These agencies and 
organizations include: The Service, the USGS, the National Oceanic and 
Atmospheric Administration, the National Park Service, the Arctic 
Institute, the North American Wildlife and Natural Resource Conference, 
the Marine Mammals of the Holarctic V Conference, and the Outer 
Continental Shelf Environmental Assessment Program. In addition, the 
Service consulted publications such as the Journal of Wildlife 
Management, Conservation Biology, Marine Mammal Science, Ecological 
Applications, Biological Conservation, Aquatic Mammals, Journal of 
Zoology, Marine Mammal Science, and other refereed journal literature, 
technical reports, and data sources in the development of these SARs. A 
complete list of citations to the scientific literature relied on for 
each of the two revised SARs is available by visiting the Service's 
Marine Mammals Management species information page at: https://alaska.fws.gov/fisheries/mmm/reports.htm. These citations are likewise 
part of each SAR and may be viewed with the documents (see ADDRESSES).

Authority

    The authority for this action is the Marine Mammal Protection Act 
of 1972, as amended (16 U.S.C. 1361 et al.).

Signing Authority

    The Director, U.S. Fish and Wildlife Service, approved this 
document and authorized the undersigned to sign and submit the document 
to the Office of the Federal Register for publication electronically as 
an official document of the U.S. Fish and Wildlife Service. Martha 
Williams, Principal Deputy Director Exercising the Delegated Authority 
of the Director, U.S. Fish and Wildlife Service, approved this document 
on June 15, 2021, for publication.

Krista Bibb,
Acting Regulations and Policy Chief, Division of Policy, Economics, 
Risk Management, and Analytics, Joint Administrative Operations, U.S. 
Fish and Wildlife Service.
[FR Doc. 2021-13227 Filed 6-23-21; 8:45 am]
BILLING CODE 4333-15-P