[Federal Register Volume 77, Number 90 (Wednesday, May 9, 2012)]
[Pages 27246-27248]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-11164]



Fish and Wildlife Service

[FWS-R8-FHC-2012-N018; FF08EVEN00-FXFR1337088SSO0L5-123]

Marine Mammal Protection Act; Stock Assessment Report

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of availability of draft revised stock assessment report 
for the southern sea otter in California; request for comments.


SUMMARY: In accordance with the Marine Mammal Protection Act of 1972, 
as amended (MMPA), and its implementing regulations, we, the U.S. Fish 
and Wildlife Service (Service), have developed a draft revised marine 
mammal stock assessment report (SAR) for the southern sea otter 
(Enhydra lutris nereis) stock in the State of California. We now make 
the SAR available for public review and comment.

DATES: We will consider comments that are received or postmarked on or 
before August 7, 2012.

ADDRESSES: If you wish to review the draft revised SAR for southern sea 
otter, you may obtain a copy from our Web site at http://www.fws.gov/ventura. Alternatively, you may contact the Ventura Fish and Wildlife 
Office, 2493 Portola Road, Suite B, Ventura, CA 93003 (telephone: 805-
644-1766). If you wish to comment on the SAR, you may submit your 
comments in writing by any one of the following methods:
     U.S. mail: Field Supervisor, at the above address;
     Hand delivery: Ventura Fish and Wildlife Office at the 
above address;
     Fax: (805) 644-3958; or
     Email: fw8ssostock@fws.gov.

FOR FURTHER INFORMATION CONTACT: Lilian Carswell, at the above street 
address, by telephone (805-612-2793), or by email (Lilian_Carswell@fws.gov).



    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,

[[Page 27247]]

purchasing, selling, offering for sale, exporting, and importing 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). 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(3)(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 established regional 
scientific review groups. Each SAR must include:
    1. A description of the stock and its geographic range;
    2. A minimum population estimate, maximum net productivity rate, 
and current population trend;
    3. An estimate of human-caused mortality and serious injury;
    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(3)(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 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.
    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 or endangered species under the ESA, or 
is designated as depleted under [the MMPA].'' 16 U.S.C. 1362(3)(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 had 
reviewed the stock assessment annually since then. In December of 2009 
and again in December of 2010, Service reviews concluded that revision 
was not warranted because the stock had not changed significantly, nor 
could it be more accurately determined. However, upon review in 2011, 
the Service determined that revision was warranted due to an increase 
in the relative number of strandings.
    The following table summarizes the information we are now making 
available in the draft revised southern sea otter SAR, which lists the 
stock's Nmin, Rmax, Fr, PBR, annual 
estimated human-caused mortality and serious injury, and status. After 
consideration of any public comments we receive, the Service will 
revise and finalize the SAR, as appropriate. We will publish a notice 
of availability and summary of the final SAR, including responses to 
submitted comments.

                Summary: Draft Revised Stock Assessment Report, Southern Sea Otter in California
                                                                         Annual estimated
                                                                       average human-caused
              Stock                  Nmin     Rmax      Fr      PBR        mortality and         Stock status
                                                                        serious injury (5-
                                                                           year average)
Southern sea otters..............    2,762     0.06      0.1        8  Due to lack of        Strategic.
                                                                        observer coverage,
                                                                        a science-based
                                                                        estimate cannot be

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 the MMPA, we include in this notice a list of 
the information sources and public reports upon which we based the SAR.

Bacon, C.E. 1994. An ecotoxicological comparison of organic 
contaminants in sea otters among populations in California and 
Alaska. M.S. thesis, University of California, Santa Cruz.
Bacon, C.E., W.M. Jarman, J.A. Estes, M. Simon, and R.J. Norstrom. 
1999. Comparison of organochlorine contaminants among sea otter 
(Enhydra lutris) populations in California and Alaska. Environ. 
Toxicology and Chemistry 18(3):452-458.
Bentall, G.B. 2005. Morphological and behavioral correlates of 
population status in the southern sea otter: a comparative study 
between central California and San Nicolas Island. Master's Thesis, 
University of California, Santa Cruz, unpublished.
Bryant, H.C. 1915. Sea otters near Point Sur. California Department 
of Fish and Game Bull. 1:134-135.
Cameron, G.A., and K.A. Forney. 2000. Preliminary estimates of 
cetacean mortality in California/Oregon gillnet fisheries for 1999. 
Paper SC/S2/O24 presented to the International Whaling Commission, 
2000 (unpublished). 12 pp. Available from NMFS, Southwest Fisheries 
Science Center, P.O. Box 271, La Jolla, California.
Carretta, J.V. 2001. Preliminary estimates of cetacean mortality in 
California gillnet fisheries for 2000. Paper SC/53/SM9 presented to 
the International Whaling Commission, 2001 (unpublished). 21 pp. 
Available from NMFS, Southwest Fisheries Science Center, P.O. Box 
271, La Jolla, California.
Cronin, M.A., J. Bodkin, B. Bellachey, J.A. Estes, and J.C. Patton. 
1996. Mitochondrial-DNA variation among subspecies and populations 
of sea otters (Enhydra lutris). J. Mammal. 77:546-557.

[[Page 27248]]

Estes, J.A. 1990. Growth and equilibrium in sea otter populations. 
J. Anim. Ecol. 59:385-401.
Estes, J.A., and R.J. Jameson. 1988. A double-survey estimate for 
sighting probability of sea otters in California. J. Wildl. Manage. 
Estes, J.A., B.B. Hatfield, K. Ralls, and J. Ames. 2003. Causes of 
mortality in California sea otters during periods of population 
growth and decline. Marine Mammal Science 19(1):198-216.
Forney, K.A., S.R. Benson, and G.A. Cameron. 2001. Central 
California gill net effort and bycatch of sensitive species, 1990-
1998. Pages 141-160 in Seabird Bycatch: Trends, Roadblocks, and 
Solutions, E.F. Melvin and J.K. Parrish, eds. Proceedings of an 
International Symposium of the Pacific Seabird Group, University of 
Alaska Sea Grant, Fairbanks, Alaska, 212 pp.
Hatfield, B.B., and J.A. Estes. 2000. Preliminary results of an 
evaluation of the potential threat to sea otters posed by the 
nearshore finfish trap fishery. Unpublished. 6 pp. plus appendices.
Hatfield, B.B., J.A. Ames, J.A. Estes, M.T. Tinker, A.B. Johnson, 
M.M. Staedler, and M.D. Harris. 2011. Sea otter morality in fish and 
shellfish traps: estimating potential impacts and exploring possible 
solutions. Endangered Species Research 13:219-229.
Herrick, S.F., Jr., and D. Hanan. 1988. A review of California 
entangling net fisheries, 1981-1986. National Oceanic and 
Atmospheric Administration Technical Memorandum. National Marine 
Fisheries Service. NOAA-TM-NMFS-SWFC-108. 39 pp.
Jameson, R.J. 1989. Movements, home range, and territories of male 
sea otters off central California. Marine Mammal Science 5:159-172.
Jameson, R.J., and S. Jeffries. 1999. Results of the 1999 survey of 
the Washington sea otter population. Unpublished report. 5 pp.
Jameson, R.J., and S. Jeffries. 2005. Results of the 2005 survey of 
the reintroduced Washington sea otter population. Unpublished 
report. 6 pp.
Jessup, D.A., M.A. Miller, M. Harris, B.B. Hatfield, and J.A. Estes. 
2004. The 2003 southern sea otter (Enhydra lutris nereis) unusual 
mortality event: A preliminary report to NOAA and USFWS. Unpublished 
report. 38pp.
Johnson, C.K., M.T. Tinker, J.A. Estes, P.A. Conrad, M. Staedler, 
M.A. Miller, D.A. Jessup, and J. A.K. Mazet. 2009. Prey choice and 
habitat use drive sea otter pathogen exposure in a resource-limited 
coastal system. PNAS 106:2242-2247.
Kannan, K., E. Perrotta, and N.J. Thomas. 2006. Association between 
perfluorinated compounds and pathological conditions in southern sea 
otters. Environmental Science & Technology 40:4943-4948.
Kannan, K., E. Perrotta, N.J. Thomas, and K.M. Aldous. 2007. A 
comparative analysis of polybrominated diphenyl ethers and 
polychlorinated biphenyls in southern sea otters that died of 
infectious diseases and noninfectious causes. Archives of 
Environmental Contamination and Toxicology 53:293-302.
Kannan K., K.S. Guruge, N.J. Thomas, S. Tanabe, J.P. Giesy. 1998. 
Butyltin residues in southern sea otters (Enhydra lutris nereis) 
found dead along California coastal waters. Environmental Science 
and Technology 32:1169-1175.
Kooyman, G.L., and D.P. Costa. 1979. Effects of oiling on 
temperature regulation in sea otters. Yearly progress report, Outer 
Continental Shelf Energy Assessment Program.
Kreuder, C., M.A. Miller, D.A. Jessup, L.J. Lowenstein, M.D. Harris, 
J.A. Ames, T.E. Carpenter, P.A. Conrad, and J.A.K. Mazet. 2003. 
Patterns of mortality in southern sea otters (Enhydra lutris nereis) 
from 1998-2001. Journal of Wildlife Diseases 39(3):495-509.
Kreuder, C., M.A. Miller, L.J. Lowenstine, P.A. Conrad, T.E. 
Carpenter, D.A. Jessup, and J.A.K. Mazet. 2005. Evaluation of 
cardiac lesions and risk factors associated with myocarditis and 
dilated cardiomyopathy in southern sea otters (Enhydra lutris 
nereis). American Journal of Veterinary Research 66:289-299.
Laidre, K.L., R.J. Jameson, and D.P. DeMaster. 2001. An estimation 
of carrying capacity for sea otters along the California coast. 
Marine Mammal Science 17(2):294-309.
Larson, S., R. Jameson, J. Bodkin, M. Staedler, and P. Bentzen. 
2002. Microsatellite DNA and mitochondrial DNA variation in remnant 
and translocated sea otter (Enhydra lutris) populations. J. Mammal. 
Mayer, K.A., M.D. Dailey, and M.A. Miller. 2003. Helminth parasites 
of the southern sea otter Enhydra lutris nereis in central 
California: abundance, distribution, and pathology. Diseases of 
Aquatic Organisms 53:77-88.
Miller, M.A., R.M. Kudela, A. Mekebri, D. Crane, S.C. Oates, M.T. 
Tinker, M. Staedler, W.A. Miller, S. Toy-Choutka, C. Domink, D. 
Hardin, G. Langlois, M. Murray, K. Ward and D.A. Jessup. 2010. 
Evidence for a novel marine harmful algal bloom: cyanotoxin 
(Microcystin) transfer from land to sea otters. PLoS ONE 5(9): 
Nakata, H., K. Kannan, L. Jing, N. Thomas, S. Tanabe, and J.P. 
Giesy. 1998. Accumulation pattern of organochlorine pesticides and 
polychlorinated biphenyls in southern sea otters (Enhydra lutris 
nereis) found stranded along coastal California, USA. Environ. Poll. 
Ralls, K., T.C. Eagle, and D.B. Siniff. 1996. Movement and spatial 
use patterns of California sea otters. Canadian Journal of Zoology 
Riedman, M.L., and J.A. Estes. 1990. The sea otter (Enhydra lutris): 
behavior, ecology, and natural history. U.S. Fish and Wildlife 
Service, Biol. Rep. 90(14). 126 pp.
Riedman, M.L., J.A. Estes, M.M. Staedler, A.A. Giles, and D.R. 
Carlson. 1994. Breeding patterns and reproductive success of 
California sea otters. J. Wildl. Manage. 58:391-399.
Sanchez, M.S. 1992. Differentiation and variability of mitochondrial 
DNA in three sea otter, Enhydra lutris, populations. M.S. Thesis, 
University of California, Santa Cruz.
Siniff, D.B., and K. Ralls. 1991. Reproduction, survival, and tag 
loss in California sea otters. Marine Mammal Science 7(3):211-229.
Siniff, D.B., T.D. Williams, A.M. Johnson, and D.L. Garshelis. 1982. 
Experiments on the response of sea otters, Enhydra lutris, to oil 
contamination. Biol. Conserv. 2:261-272.
Taylor, B.L., M. Scott, J. Heyning, and J. Barlow. 2002. Suggested 
guidelines for recovery factors for endangered marine mammals. 
Unpublished report submitted to the Pacific Scientific Review Group. 
7 pp.
Tinker, M.T., G. Bentall, and J.A. Estes. 2008. Food limitation 
leads to behavioral diversification and dietary specialization in 
sea otters. PNAS 105:560-565.
Tinker, M.T., J.A. Estes, K. Ralls, T.M. Williams, D. Jessup, and 
D.P. Costa. 2006. Population Dynamics and Biology of the California 
Sea Otter (Enhydra lutris nereis) at the Southern End of its Range. 
MMS OCS Study 2006-007. Coastal Research Center, Marine Science 
Institute, University of California, Santa Barbara, California. MMS 
Cooperative Agreement Number 14-35-0001-31063.
U.S. Fish and Wildlife Service. 2003. Final Revised Recovery Plan 
for the Southern Sea Otter (Enhydra lutris nereis). Portland, 
Oregon. 177 pp.
Valentine, K., D.A. Duffield, L.E. Patrick, D.R. Hatch, V.L. Butler, 
R.L. Hall, and N. Lehman. 2008. Ancient DNA reveals genotypic 
relationships among Oregon populations of the sea otter (Enhydra 
lutris). Conservation Genetics 9(4):933-938.
Wendell, F.E., R.A. Hardy, and J.A. Ames. 1986. An assessment of the 
accidental take of sea otters, Enhydra lutris, in gill and trammel 
nets. California Department of Fish and Game, Mar. Res. Tech. Rep. 
1991. Geographic variation in sea otters, Enhydra lutris. J. Mammal. 
Wilson, D.E., M.A. Bogan, R.L. Brownell, Jr., A.M. Burdin, and M.K. 
Maminov. 1991. Geographic variation in sea otters, Enhydra lutris. 
J. Mammal. 72(1):22-36.


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

    Dated: April 29, 2012.
Gregory E. Siekaniec,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2012-11164 Filed 5-8-12; 8:45 am]