[Federal Register Volume 60, Number 192 (Wednesday, October 4, 1995)]
[Notices]
[Pages 52008-52012]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-24622]
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DEPARTMENT OF THE INTERIOR
Marine Mammals; Stock Assessment Reports
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of completion and availability of final marine mammal
stock assessments and guidelines for preparing stock assessments.
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SUMMARY: Section 117 of the 1994 amendments to the Marine Mammal
Protection Act (MMPA) requires the Fish and Wildlife Service (Service)
and the National Marine Fisheries Service (NMFS) to prepare stock
assessments for each marine mammal stock that occurs in waters under
the jurisdiction of the United States. The Service made draft stock
assessments and preliminary guidelines available for public review and
comment on August 23, 1994. Comments received from the public and from
scientific review groups (established according to section 117) were
reviewed and incorporated into the reports and guidelines, as
appropriate. Final stock assessments have been completed and are now
available for polar bears, walrus, and northern sea otters in Alaska;
southern sea otters in California and northern sea otters in Washington
State; and two West Indian manatee stocks in the southeastern United
States and Puerto Rico. Final guidelines for preparing these stock
assessments are also available.
ADDRESSES: Copies of these final stock assessments and final guidelines
are available from the Division of Fish and Wildlife Management
Assistance, U.S. Fish and Wildlife Service, Mail Stop 840-ARLSQ, 1849 C
Street NW., Washington, D.C. 20240.
FOR FURTHER INFORMATION CONTACT: Jeff Horwath, Division of Fish and
Wildlife Management Assistance, Arlington, Virginia, at 703/358-1718.
For specific information about stock assessments for polar bears,
walrus, and northern sea otters in Alaska, contact David McGillivary in
the Service's Office of Marine Mammals Management, Anchorage, Alaska,
at 907/786-3800. For specific information about stock assessments for
southern sea otters in California and northern sea otters in Washington
State, contact Carl Benz in the Service's field office in Ventura,
California, Telephone 805/644-1766. For specific information about
stock assessments for West Indian manatees in the southeastern United
States and Puerto Rico, contact Robert Turner in the Service's field
office in Jacksonville, Florida, Telephone 904/232-2580.
SUPPLEMENTARY INFORMATION: On April 30, 1994, the MMPA Amendments of
1994 were enacted into law (Public Law 103-238). New section 117 of the
MMPA required the Service and the NMFS (as appropriate) to prepare and
periodically revise stock assessments for marine mammals that occur in
waters
[[Page 52009]]
under the jurisdiction of the United States. These reports must contain
information regarding the distribution and abundance of the stocks,
population growth rates and trends, estimates of annual human-caused
mortality from all sources, descriptions of the fisheries with which
the stocks interact, and the status of each stock.
Although many of the items included in the reports were described
explicitly in the MMPA, many elements, including a quantitative
definition of the parameters used in calculating Potential Biological
Removal (PBR) levels, were defined only in general terms. To promote
consistent interpretation of the provisions of the law, the NMFS
convened a workshop composed of NMFS and FWS scientists in June 1994 to
develop preliminary guidelines to be used in preparing draft stock
assessments.
On August 23, 1994, the Service published in the Federal Register a
notice of availability of draft guidelines and stock assessments (59 FR
43353) for polar bears, Pacific walrus, and Alaska sea otters in
Alaska, southern sea otters in California and northern sea otters in
Washington State, and West Indian manatees in the southeastern United
States and Puerto Rico. A 90-day public comment period expired on
November 21, 1994. Substantial background information was provided in
that notice, and is not repeated at this time. On November 16, 1994,
the Service, in response to public concerns, extended the public
comment period through December 1, 1994 (59 FR 59243). This new
expiration date provided several additional days for public comment
while reducing public confusion by aligning the Service's cut-off date
with that of the NMFS; that agency was developing their own stock
assessments and had also extended their comment period to December 1,
1994. The Service also concluded that it would allow a reasonable
amount of time for the Alaska Scientific Review Group (see next two
paragraphs) to review public comments prior to the Group's scheduled
meeting of December 12-13, 1994.
In addition to the requirements to develop stock assessments,
section 117 of the amendments to the MMPA also required the NMFS, in
consultation with the Service and others, to establish three
independent regional Scientific Review Groups (SRG) representing
Alaska, the Pacific Coast (including Hawaii), and the Atlantic Coast
(including the Gulf of Mexico). These SRG's were charged with providing
advice on the stock assessments and other issues appropriate for
pursuing the goals of the MMPA.
Subsequent to the close of the comment period for the draft stock
assessments, the Service provided copies of public comments, as
appropriate, to members of the Alaska, Pacific, and Atlantic SRG's for
review and consideration. All public comments and the input of the
appropriate SRG's was considered by the Service in producing the final
stock assessments announced by this Federal Register notice. Final
guidelines have also been completed. Following is a brief summary of
comments received and the Service's response to those comments.
Comments
Polar Bear
Multiple stock assessment versus single stock assessment. Comment:
Public comment favored development of two independent stock assessments
versus one combined stock assessment for both the Beaufort Sea and
Chukchi/Bearing Seas stocks. Response: The Service agrees and has
recognized the information on the two stocks contained in the initial
draft stock assessment into two individual final stock assessments.
Minimum population estimate. Comment: Public comment was not
received on the minimum population estimate for the Beaufort Sea stock
or lack of an estimate for the Chukchi/Bearing Seas stock. However, a
reanalysis of Service/National Biological Service mark and recapture
data for the Beaufort Sea stock resulted in a revised N(min)
estimate of 1,717 animals.
Maximum productivity rates. Comment: One organization, and an
observer at the Alaska SRG commented that the initial R(max) value
of 10 percent was greater than observed rates and suggested that a
review of data used for the calculation be conducted. Response: The
R(max) from the draft stock assessment was revised based on
modeling of observed reproduction and survival rates for polar bears in
the Beaufort Sea stock. A 6 percent value is now used.
Mortality. Comment: Several commenters suggested that the Service
should present the harvest averages for the last 5-year period instead
of the longer-term averages. Response: The Service concurs and has
modified the stock assessments accordingly. A common concern was that
modeling the effects of mortality did not account nor make adjustment
for the skewed sex ratio of the harvest. The final estimate of the
Potential Biological Removal (PBR) level for the Beauford Sea stock
includes the appropriate adjustment for the sex of harvested animals.
Status of stock. Comment: One comment stated that polar bear stocks
in Alaska should be designated as ``strategic'' because of the lack of
information regarding population size and status, inherently low
reproductive capability, and threats emanating from the harvest rates
and industry. Response: The Service has concluded that the stocks are
``non-strategic.'' The rationale for these decisions are described in
detail within the stock assessment and the calculations of PBR.
Pacific Walrus
Minimum population estimate. Comment: Several groups believed this
estimate should be based on the estimated population size obtained
during the last range-wide aerial survey (1990). They pointed out the
survey was conducted during an ice minimum period when only a few
walrus were counted along the ice edge. While many walrus were counted
on land, presumably many more were in the water and were not counted.
Response: The stock assessment report follows guidelines outlined in
the NMFS Workshop Report to use the best available scientific
information to calculate the minimum population estimate, (Nmin),
not the total estimated population, (Nbest). The minimum estimate
obtained is based on a sum of the direct counts of the walrus observed
on land, plus the adjusted estimate of that portion of the population
observed on the ice.
Maximum productivity rates. Comment: Several groups suggested the
0.06 value for Rmax in the draft stock assessment was too low; one
group believed it to be too high. Response: Commenting groups typically
confused the term maximum net productivity, as defined by the amended
MMPA and the PBR Workshop, with maximum productivity. The available
data for maximum growth at a small population size for the Pacific
walrus are scant. Estimated values of Rmax derived from population
models are equivocal. In our reassessment, the Service consulted with
experts from several agencies and the Alaska SRG. Recognizing the
limitations of the best available data and that the Rmax value
proposed in the draft stock assessment may not fully account for a
skewed sex ratio in the population, the Service chose to follow the
recommendation of the Alaska SRG to tentatively adopt 0.08 as a more
plausible estimate of Rmax. The Service is in the process of
reviewing available information and is open to revision of
[[Page 52010]]
this value when and if it becomes appropriate.
Mortality. Comment: Several groups questioned the use of
calculating the estimated average annual mortality due to subsistence
harvest on the basis of a 30 year data set. Some groups believed the
estimate of struck and lost was too high. Response: The Service agrees
that using the most recent 5-year period to calculate average annual
mortality is an approach which more accurately reflects current harvest
trends and levels; the value was recalculated using new information
from Russian colleagues obtained since publication of the draft stock
assessment. While the available information on struck and lost rates is
somewhat dated (collected during the late 1960's-early 1970's), it is
the only sound scientific information collected to date. The Service
believes it is appropriate to use these data until such time as newer
scientifically rigorous data can be obtained.
Status of stock. Comment: Several groups objected to the draft
stock assessment's categorization of the Pacific walrus stock as
``strategic.'' Response: Using the new, updated, and adjusted
information discussed above and presented in the final stock
assessment, the Service has concluded the stock is ``non-strategic.''
Northern Sea Otter in Alaska
Single species focus. Comment: The stock assessment inappropriately
focused on a single species. It should have included Alaska Natives in
its focus. Response: The stock assessment was developed based on the
MMPA requirements and guidance developed for all stock assessments
which focused on the status, incidental fisheries take, and other human
take of marine mammal species.
Multiple stocks vs. single stock. Comment: The Service was
inconsistent on the treatment of single versus multiple stocks. Several
commenters suggested that sea otters should be treated as multiple
stocks, while others agreed with a single Alaska stock. Response: The
Service will continue to consider splitting the Alaska stock of sea
otters into multiple stocks if the scientific data supports such a
split.
Minimum population estimate. Comment: Several commenters suggested
that the minimum population estimate was too low since they believed
that sea otter populations in Alaska have been growing rapidly. Others
concurred with the minimum population estimate. Response: The Service
is aware of the uncertainty of the population abundance of Alaska sea
otters. This is based on the fact that survey results are dated and
variable. The stock assessment followed the guidelines and used the
best available information to calculate the minimum population
estimate, not the total estimated population. Additional language was
added to clarify the variability of survey results. Additionally, the
table in the stock assessment was updated to include more recent data
that had become available.
Potential Biological Removal. Comment: Commenters suggested that
the Potential Biological Removal level should not be determined because
of the uncertainty associated with the minimum population estimate and
the lack of current survey information. Response: See ``Minimum
population estimate'' discussion above.
Maximum productivity rate. Comment: Several commenters suggested
that the maximum productivity rate was too high, while another believed
it to be accurate. Response: After reviewing public comments and the
comments of the Alaska Scientific Review Group, the maximum
productivity rate was increased to 20 percent based on information in
the scientific literature.
Incidental take. Comment: Comments were received describing the
incidental take of sea otters by commercial fisheries as insignificant,
while another commenter suggested that our incidental take data was
inadequate to evaluate commercial fishery interactions. Response: The
best available information was used by the Service. If more information
becomes available, future stock assessments will be modified
accordingly.
Native harvest. Comment: One commenter believed that too much
information was provided on Native harvest while another suggested
expanding the section to describe geographic patterns of Native
harvest. Response: Because the focus of the stock assessment was to be
commercial fisheries incidental take, other human-caused mortality was
generally described. In the case of human-caused mortality to sea
otters, this includes Native harvest.
Other human-caused mortality. Comment: The comment was received
that the section on human-caused mortality should be expanded to
include historic information. Response: This section was expanded.
Southern Sea Otter in California
Annual human-caused mortality. Comment: Sentiment was expressed
that the Service needs to clarify that southern sea otter mortality
attributable to drowning in lobster pots is unknown, but may be a
significant contributor to the lack of population growth at San Nicolas
Island. It was further stated that this information should be included
in the ``Fisheries Information'' section of the stock assessment.
Response: The Service agrees; comments were incorporated into the final
stock assessment.
Potential Biological Removal (PBR). Comment: Comment was received
that the stock assessment should clarify that the NMFS will defer to
the opinion of the Service regarding PBR for this species, and that the
option of the Service is that incidental take should remain at zero.
Response: This comment was noted but not incorporated into the final
stock assessment. The section on PBR has been expanded and retains the
clarification that the 1994 amendments to the MMPA do not pertain to
the southern sea otter. No take is allowed.
Endangered Species Act (ESA) listing, recovery plan, and
translocation effort. Comment: Comments were received that the final
stock assessment should: (1) Note the date and reason for listing this
stock as threatened under the ESA; (2) indicate that a recovery plan
has been developed and is being revised; (3) explain that the Service
has attempted to establish a reserve population at San Nicolas Island,
California; (4) discuss Public Law 99-625 and the closely associated
Management Zone to prohibit range expansion and protect fishery
resources; (5) indicate that a number of otters have entered the
Management Zone and have died, or may have died, as a consequence of
efforts to capture and remove them; and (6) discuss that an uncertain
number of sea otters may have been killed in recent years by small oil
spills and unusual diseases. Response: These comments were incorporated
into the final stock assessment.
Maximum productivity rate. Comment: Comment was received that
R(max) for the southern sea otter appeared to be closer to 4
percent or 5 percent rather than the 6 percent rate used in the stock
assessment and that this should be explained. Response: The 6 percent
rate continues to be used in the final stock assessment. The Service
believes that adequate data is presented in the ``Current and Maximum
Net Productivity Rates'' section to justify use of the 6 percent rate.
Comment: One commenter believed that the Service should note that
before 1985, when such fisheries were prohibited, the take of southern
sea otters was far above the estimates of PBR. Therefore, if
restrictions on gill nets were lifted, then the southern sea
[[Page 52011]]
otter would be designated as a ``strategic stock,'' requiring formation
of a Take Reduction Team to advise on measures that should be taken to
ensure that incidental take does not exceed the PBR. Response: The
final stock assessment was modified to incorporate these comments.
Northern Sea Otter in Washington State
Annual human-caused mortality. Comment: The Service should
elucidate Indian treaty rights, particularly in relation to MMPA
recovery objectives. It was further stated that this information should
be included in the ``Fisheries Information'' section of the stock
assessment. Response: The ``Annual Human-Caused Mortality'' section of
the stock assessment was changed to acknowledge the tribal rights
claim. However, until this issue is legally clarified, the Service is
unable to provide better information and guidance.
Comment: A comment was received that the Service should identify
the number and source(s) of animals translocated to Washington State.
Response: These comments were incorporated into the final stock
assessment.
Maximum Productivity Rate. Comment: One commenter stated that the
Service should describe and discuss data used to determine that
R(max) is 12 percent for the Alaska sea otter in Washington State.
Response: The ``Population Size'' section was modified slightly and now
describes the type of data and survey techniques used. However, actual
survey counts were not included in the final stock assessment.
Sea otter/fishery interaction. Comment: One commenter indicated
that the Service should include information on sea otter/fishery
interactions in Washington State. Response: This suggestion was
incorporated into the final stock assessment.
Comment: One commenter stated that the Service should indicate the
present distributions of sea otters and gil-net fisheries in Washington
State coastal waters. Response: The Service agrees and has incorporated
the comment into the final stock assessment.
West Indian Manatees
Annual mortality data. Comment: Comments was received that the
Service should use the most recent mortality data for the Florida
manatee. Response: The Service concurs. Summary data through December
1994, as provided by the Florida Department of Environmental
Protection, has been incorporated into the final stock assessment.
Stock definition and range. Comment: One commenter questioned the
Service's definition of a single stock of Florida manatees and
suggested that an Atlantic coast stock and a Gulf coast stock would be
more appropriate. Response: The Service considered the merits of
delineating two stocks of Florida manatees, but prefers to retain a
single stock classification, noting that genetic studies published to
date do not strongly support the definition of clearly distinct stocks.
Furthermore, intensive studies of far south Florida manatee movements
are lacking, and it may be premature to conclude that no genetic
exchange between Atlantic coast and Gulf coast animals. Should new
information become available, the Service will re-evaluate the stock
definition as needed. Such re-evaluations will be easily accommodated,
especially in light of section 117 of the MMPA that requires annual
review and, if appropriate, revision of stock assessments for strategic
stocks. West Indian manatees, in light of their endangered status, are
classified as strategic animals.
Potential Biological Removal. Comment: Concerns were raised about
the designation of a PBR level for manatees and the implications for
Section 7 consultations under ESAct and incidental take policy
regarding manatees. Response: The Service has already addressed these
concerns in the narrative of the assessments.
Summary of Final Stock Assessments
Along with the requirement of section 117(b)(3) of the 1994
amendments to the MMPA that require publication in the Federal Register
of a notice of availability of final stock assessments, a summary of
those final stock assessments must also be published. Appropriately,
the following table lists summary information for the Service's final
stock assessments for polar bears, walrus, and northern sea otters in
Alaska, southern sea otters in California and northern sea otters in
Washington State; and two West Indian manatee stocks in the
southeastern United States and Puerto Rico.
Dated: September 20, 1995.
John G. Rogers, Jr.,
Acting Director, U.S. Fish and Wildlife Service.
Summary of marine Mammal Stock Assessments for Species of Marine Mammals Under Fish and Wildlife Service Management Authority
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Annual
estimated Annual
Species Stock area SRG FWS N(min) R(max) F(r) PBR average human- fishing- Strategic
region region caused caused status
mortality mortality
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Polar bear-Chukchi/ Chukchi and Bering AKA 7 \1\ N/AV \1\ N/AV 1.0 \1\ N/AV 55........... 0............ No.
Bering Sea stock. Seas-Alaska and
Russia.
Polar bear-Beaufort Beaufort Sea-Alaska AKA 7 1,579 0.06 1.0 \2\ 72 63........... 0............ No.
Sea stock. and Canada.
Sea otter-Alaska stock Alaska............... AKA 7 100,000 0.2 1.0 10,000 506.......... <1........... no.="" pacific="" walrus........="" alaska="" and="" russia....="" aka="" 7="" 188,316="" 0.08="" 1.0="" 7,533="" 5,895........="" 16...........="" no.="" west="" indian="" manatee-="" southeastern="" u.s.a...="" atl="" 4="" 1,822="" 0.04="" 0.1="" 3="" \3\="" 49.......=""><1........... yes.="" florida="" stock.="" [[page="" 52012]]="" west="" indian="" manatee-="" puerto="" rico..........="" atl="" 4="" 86="" 0.04="" 0.1="" 0="" 2............="" unknown......="" yes.="" antillean="" stock.="" southern="" sea="" otter-="" central="" california="" pac="" 1="" 2,376="" 0.06="" 0.1="" \4\="" n/ap="" \5\="" unknown..="" \6\="" unknown..="" yes.="" california="" stock.="" and="" san="" nicolas="" island.="" sea="" otter-washington="" neah="" bay="" to="" pac="" 1="" 360="" 0.12="" 0.5="" 11="" \7\="" unknown..="" \6\="" unknown..="" no.="" stock.="" destruction="" island,="" wa.="" --------------------------------------------------------------------------------------------------------------------------------------------------------="" \1\="" n/av="" indicates="" not="" available.="" \2\="" adjusted="" upwards="" to="" 72="" animals="" from="" the="" calculated="" pbr="" of="" 48="" to="" reflect="" the="" approximate="" 2="" male:1="" female="" sex="" ratio="" of="" the="" harvest.="" see="" stock="" assessment="" for="" additional="" information.="" \3\="" estimated="" average="" human-caused="" mortality="" for="" the="" west="" indian="" manatee--florida="" stock="" from="" 1984-1992.="" the="" estimated="" average="" annual="" human="" caused="" mortality="" from="" 1974-1992="" is="" 36="" animals.="" \4\="" n/ap="" indicates="" not="" applicable.="" although="" the="" pbr="" level="" for="" the="" southern="" sea="" otter--california="" stock="" was="" calculated="" to="" be="" 7,="" their="" incidental="" take="" is="" not="" governed="" under="" section="" 118="" of="" the="" 1994="" amendments="" to="" the="" marine="" mammal="" protection="" act.="" \5\="" unknown.="" human="" caused="" mortalities="" of="" sea="" otters="" have="" been="" attributed="" to="" drowning="" in="" gill="" nets="" and="" lobster/crab="" pots,="" shootings,="" boat="" collisions,="" disease,="" and="" oil="" spills.="" however,="" data="" are="" insufficient="" for="" estimating="" annual="" losses.="" see="" stock="" assessment="" for="" additional="" information.="" \6\="" unknown.="" observer="" coverage="" is="" inadequate="" to="" estimate="" annual="" fishery="" mortality.="" \7\="" sea="" otters="" in="" washington="" state="" ares="" susceptible="" to="" the="" same="" sources="" of="" human-caused="" mortality="" as="" they="" are="" in="" california.="" [fr="" doc.="" 95-24622="" filed="" 10-3-95;="" 8:45="" am]="" billing="" code="" 4310-55-m="">