[Federal Register Volume 79, Number 14 (Wednesday, January 22, 2014)]
[Notices]
[Pages 3612-3614]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-01145]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[FWS-R8-FHC-2013-N101; FF08EVEN00-FXFR1337088SSO0-134]


Marine Mammal Protection Act; Stock Assessment Report

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of availability of final report; response to comments.

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SUMMARY: In accordance with the Marine Mammal Protection Act of 1972,

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as amended (MMPA), and its implementing regulations, we, the U.S. Fish 
and Wildlife Service (Service), announce that we have revised our stock 
assessment report (SAR) for the southern sea otter (Enhydra lutris 
nereis) stock in California State, including incorporation of public 
comments. We now make our final revised SAR available to the public.

ADDRESSES: Document Availability: You may obtain a copy of the SAR from 
our Web site at http://www.fws.gov/ventura/species_information/so_sea_otter/index.html. Alternatively, you may contact the Ventura Fish 
and Wildlife Office, U.S. Fish and Wildlife Service, 2493 Portola Road, 
Suite B, Ventura, CA 93003; telephone: 805-644-1766.

FOR FURTHER INFORMATION CONTACT: For information on the methods, data, 
and results of the stock assessment, contact Lilian Carswell by 
telephone (805-612-2793) or by email ([email protected]). 
Persons who use a telecommunications device for the deaf (TDD) may call 
the Federal Information Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Background

    Under the MMPA (16 U.S.C. 1361 et seq.) and its implementing 
regulations in the Code of Federal Regulations (CFR) at 50 CFR part 18, 
we regulate the taking, possession, transportation, purchasing, 
selling, offering for sale, exporting, and importing 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 (OSP) 
level. 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. 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 annual human-caused mortality and serious injury 
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. This can be written as:

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

    Section 117 of the MMPA 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.) [the ``ESA''], within the foreseeable future; or 
(C) which is listed as a threatened species or endangered species under 
the [ESA], or is designated as depleted under [the MMPA].'' (16 U.S.C. 
1362(19)).
    The southern sea otter SAR was last revised in December, 2008. 
Because the southern sea otter qualifies as a strategic stock due to 
its listing as a threatened species under the ESA, the Service reviewed 
the stock assessment in December of 2009 and again in December of 2010. 
Both reviews concluded that the status had not changed, nor could it be 
more accurately determined. However, upon review in 2011, the Service 
determined that revision was warranted.
    Before releasing our draft SAR for public review and comment, we 
submitted it for technical review internally and also for scientific 
review by the Pacific Regional Scientific Review Group, which was 
established under the MMPA (16 U.S.C. 1386(d)). In a May 9, 2012 (77 FR 
27246), Federal Register notice, we made our draft SAR available for 
the MMPA-required 90-day public review and comment period. Following 
the close of the comment period, we revised the SAR based on public 
comments we received (see Response to Public Comments) and prepared the 
final revised SAR. Between publication of the draft and final revised 
SARs, we have not revised the status of the stock itself (the southern 
sea otter continues to retain its status as a strategic stock). 
However, we have updated the SAR to include the most recent information 
available.
    The following table summarizes the final revised SAR for southern 
sea otters in California, listing the stock's Nmin, 
Rmax, Fr, PBR, annual estimated human-caused 
mortality and serious injury, and status:

                                 Summary: Final Revised Stock Assessment Report for the Southern Sea Otter in California
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                                                                                                  Annual estimated human-
                  Stock                        Nmin         Rmax          Fr          PBR      caused mortality and serious          Stock status
                                                                                                          injury
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Southern sea otter.......................        2,924         0.06          0.1            8  Figures by specific source,   Strategic.
                                                                                                where known, are provided
                                                                                                in the SAR.
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Response to Public Comments

    We received comments on the draft SAR (77 FR 27246) from the Marine 
Mammal Commission and the Center for Biological Diversity. We present 
substantive issues raised in those comments that are pertinent to the 
SAR, along with our responses, below.
    Comment 1: While the SAR states that southern sea otter mortalities 
in gillnets

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are believed to be currently at or near zero, there is insufficient 
observer coverage for reliable estimates. In 2010, observations in the 
swordfish and thresher shark fishery were only 11.9 percent observer 
coverage. In the halibut and white seabass set gillnet fishery, 
observer coverage was at 12.5 percent. In the yellowtail, barracuda, 
and white seabass drift gillnet only, 4.6 percent of sets were 
observed. These levels of observer coverage are far below NMFS's goal 
of 20 percent observer coverage to achieve reliable estimates of marine 
mammal take. The Service should update its data for observer reports to 
the present and note that the observer coverage is too low for reliable 
estimates for take.
    Response: We state that southern sea otter mortalities resulting 
from entanglement in gill nets are likely to be at or near zero because 
of the depth restrictions that are in place and the current extent of 
the southern sea otter's range. However, we acknowledge that individual 
sea otters may occasionally transit areas that are not subject to 
closures and that levels of observer coverage of gill and trammel net 
fisheries that may interact with sea otters are low (for those 
fisheries that are observed at all). We have added the statement that 
levels of observer coverage of gill and trammel net fisheries are 
insufficient to confirm an annual incidental mortality and serious 
injury rate of zero in these fisheries. We have updated the SAR to 
include the most recent information currently available on observer 
coverage (through 2012).
    Comment 2: The SAR should estimate disease mortalities and report 
them. Studies have linked the diseased sea otters with Toxoplasma, 
which is likely a result of cat feces in land-based freshwater runoff.
    Response: We have added an estimate of mortality due to microcystin 
intoxication to our discussion of non-fishery-related anthropogenic 
mortality in the SAR. We discuss protozoal encephalitis, including that 
caused by Toxoplasma gondii, in this same section of the SAR (``Other 
Mortality''), but we do not include an estimate of the deaths caused by 
T. gondii in our estimate of annual anthropogenic mortality due to non-
fishery-related causes because the anthropogenic contribution to these 
disease levels in sea otters is not sufficiently understood.
    Comment 3: The habitat section should also include information 
about ocean acidification threats to habitat and prey of the southern 
sea otter. Sea otters consume calcifying organisms that are at risk 
from ocean acidification. Coastal waters of California are among the 
most vulnerable to ocean acidification. Survey observations reported 
that during the upwelling season California's coast is already being 
exposed to corrosive waters. This can have a detrimental effect on 
marine habitats, by reducing growth, calcification, survival, and 
reproduction of many marine organisms. Ocean acidification has been 
definitively linked to massive oyster die-offs in Oregon.
    Response: We have added information about the potential threat to 
sea otters posed by ocean acidification to the ``Habitat Issues'' 
section of the SAR.
    Comment 4: The threat of entanglement in marine debris, derelict 
fishing gear, and plastic should be discussed in the habitat section.
    Response: We list the number of known sea otter entanglements in 
marine debris and fishing gear under the heading ``Human-Caused 
Mortality and Serious Injury.'' Therefore, we have not added a 
discussion of these threats to the ``Habitat Issues'' section of the 
SAR.
    Comment 5: The SAR should be updated with the current status of 
progress on ending the no otter zone.
    Response: We have updated the SAR to indicate that the 
translocation program and its respective translocation and management 
zones were terminated by a rulemaking published on December 19, 2012 
(77 FR 75266).

Additional References Cited

Kroeker, K.J., R.L. Kordas, R.N. Crim, and G.G. Singh. 2010. Meta-
analysis reveals negative yet variable effects of ocean 
acidification on marine organisms. Ecology Letters 13:1419-1434.
Kurihara, H., T. Asai, S. Kato, and A. Ishimatsu. 2008. Effects of 
elevated pCO2 on early development in the mussel Mytilus 
galloprovincialis. Aquatic Biology 4:225-233.
Monson, D.H., J.A. Estes, J.L. Bodkin, and D.B. Siniff. 2000. Life 
history plasticity and population regulation in sea otters. Oikos 
90:457-468.
Stumpp, M., J. Wren, Frank Melzner, M.C. Thorndyke, and S.T. Dupont. 
2011. CO2 induced seawater acidification impacts sea 
urchin larval development I: Elevated metabolic rates decrease scope 
for growth and induce developmental delay. Comparative Biochemistry 
and Physiology, Part A: Molecular & Integrative Physiology 
160(3):331-340.

Authority

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

    Dated: January 8, 2014.
Stephen Guertin,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2014-01145 Filed 1-21-14; 8:45 am]
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