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Marine Mammal Protection Act; Stock Assessment Reports

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Fish and Wildlife Service, Interior.


Notice of availability of draft revised marine mammal stock assessment reports for two stocks of polar bears; request for comments.


In accordance with the Marine Mammal Protection Act of 1972, as amended and its implementing regulations, we, the U.S. Fish and Wildlife Service, have developed draft revised marine mammal stock assessment reports for each of the two polar bear (Ursus maritimus) stocks in Alaska: The Southern Beaufort Sea polar bear stock and the Chukchi/Bering Seas polar bear stock. These two draft stock assessment reports are available for public review and comment.


We must receive comments by September 20, 2017.


To obtain the draft Stock Assessment Report for either polar bear stock, and to submit comments, see Document Availability and Public Comment, respectively, under SUPPLEMENTARY INFORMATION.

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Patrick Lemons, Marine Mammals Management Office, (800) 362-5148 or via email

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Under the Marine Mammal Protection Act (16 U.S.C. 1361 et seq., MMPA) 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 MMPA's goals 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 us and the National Marine Fisheries Service (NMFS) to prepare a Stock Assessment Report (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 regional scientific review groups (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 rates, 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;

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 Start Printed Page 28527rate 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 NMFS to review the SARs (a) at least annually for 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 bears 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. Therefore, the Service 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 obtained advice from the Alaska SRG. Therefore, these draft SARs incorporate the comments and suggestions provided to the Service by the Alaska SRG as appropriate.

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

The following table summarizes some of the information contained in the draft 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. After consideration of any public comments we receive, we will revise and finalize these SARs, as appropriate. We will publish a notice of availability and summary of the final SARs, including responses to comments we received.

Table 1—Summary: Draft Revised Stock Assessment Reports for the Southern Beaufort Sea Polar Bear and Chukchi/Bering Seas Polar Bear Stocks

Polar bear stockNminRmaxFrPBRAnnual estimated human-caused mortality and serious injury, 2006-2015Stock status
Southern Beaufort Sea7820.0750.514Annual estimated removals for each stock are provided in the SARsStrategic.
Chukchi/Bering Seas2,0000.06030.530Strategic.

Document Availability

Draft Revised SARs for Southern Beaufort Sea Polar Bear and Chukchi/Bering Seas Polar Bear Stocks

You may obtain copies by any one of the following methods:

  • Internet:​fisheries/​mmm/​polarbear/​reports.htm (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) Patrick Lemons, Chief, U.S. Fish and Wildlife Service, Marine Mammals Management Office, 1011 East Tudor Road, Anchorage, Alaska 99503; telephone: (800) 362-3800.

Public Comment

Draft Revised SARs for Southern Beaufort Sea Polar Bear and Chukchi/Bering Seas Polar Bear Stocks

You may submit a written comment by any one of the following methods:

  • Email:
  • Mail or hand-delivery: Chief, Marine Mammals Management Office (see address above).
  • Fax: (907) 786-3816.

Public Availability of Comments

Before including your address, phone number, email address, or other personal identifying information in your comment, you should be aware that your entire comment—including your personal identifying information—may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.


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 draft 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 U.S. Geological Survey, 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 from the Service by visiting the Service's Marine Mammal Management office's species information page at:​fisheries/​mmm/​Start Printed Page 28528reports.htm. These citations are likewise part of each draft SAR and may be reviewed with the documents (see Document Availability).

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

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Dated: April 27, 2017.

James W. Kurth,

Acting Director, U.S. Fish and Wildlife Service.

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[FR Doc. 2017-13060 Filed 6-21-17; 8:45 am]