[Federal Register Volume 67, Number 165 (Monday, August 26, 2002)]
[Notices]
[Pages 54792-54794]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21654]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 081202A]


New Information Indicates Fine-scaled Stock Structure for Harbor 
Seals in Alaska

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of information; request for comments.

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SUMMARY: Recent studies indicate that stock structure of harbor seals 
in Alaska is more finely scaled than Stock Assessment Reports (SARs), 
compiled pursuant to the Marine Mammal Protection Act (MMPA), currently 
indicate. Under Section 119 of the MMPA, NMFS has entered into a co-
management agreement to conserve Alaska harbor seals jointly with the 
Alaska Native Harbor Seal Commission (ANHSC). NMFS and the ANHSC have 
outlined a process for proceeding with further evaluating and revising 
harbor seal stock structure. This notice invites the public to provide 
additional information and viewpoints that should be considered 
throughout the stock structure evaluation process.

DATES: Comments must be received before close of business on September 
25, 2002.

ADDRESSES: Comments should be forwarded to P. Michael Payne, Assistant 
Regional Administrator for Protected Resources, Alaska Regional Office, 
NMFS, Juneau, Alaska 99802.

FOR FURTHER INFORMATION CONTACT: Kaja Brix, Alaska Regional Office, 
NMFS, Juneau, Alaska, (907) 586-7824; or Thomas Eagle, Office of 
Protected Resources, NMFS, Silver Spring, MD, (301) 713-2322, ext. 105.

SUPPLEMENTARY INFORMATION:

Electronic Access

    This notice and a map of the areas in Alaska where seal groupings 
appear discrete may be found at www.fakr.noaa.gov/protectedresources.

Background

    Section 3 of the MMPA defines a population stock (referred to as 
``stock'' in this notice) as ``...a group of marine mammals of the same 
species or smaller taxon in a common spatial arrangement that 
interbreed when mature.'' Section 117 of the MMPA requires that NMFS 
publish stock assessments for each marine mammal stock under its 
jurisdiction. These stock assessment reports (SARs) provide a summary 
of information on each stock's geographic range, abundance, and annual 
productivity. Additionally, SARs provide information about human-caused 
sources of mortality or serious injury for each marine mammal stock. An 
accurate characterization of stocks is necessary to meet the goals of 
the MMPA.
    While the MMPA does not provide further guidance for identifying 
marine mammal stocks other than the definition above, NMFS describes 
its recommended approach to stock identification in its guidelines for 
preparing stock assessment reports. This approach is based on language 
in the purposes and policies sections of the MMPA that asserts that 
population stocks of marine mammals should not be permitted to diminish 
beyond the point at which they cease to be a functioning element of the 
ecosystem of which they are a part. The guidelines further note that a 
stock is a management unit that identifies a demographically isolated 
biological population. At the same time, the guidelines acknowledge the 
difficulties in obtaining comprehensive stock structure information due 
to resource constraints.
    The guidelines state that careful consideration needs to be given 
to how stocks are defined, particularly where mortality may be greater 
than sustainable levels (above the calculated Potential Biological 
Removal level). An inappropriately defined stock could lead to 
localized depletions or extirpations.
    Long-term movements and dispersal of marine mammals impact the 
genetic makeup of these animals. For instance, a small amount of 
breeding among individuals can be enough to prevent strong genetic 
differences from developing among adjacent groups of animals. When 
genetic differences are found among groups of seals, this indicates 
that gene flow, and movement or dispersal, among the groups is 
extremely low. Therefore, results of studies that show significant 
genetic differences provide a minimum estimate of the degree of 
population or stock structure. In other words, if a genetic analysis 
reveals some number of distinct, genetically differentiated units, a 
minimum of that number of demographically independent units is 
virtually certain.
    Under Section 119 of the MMPA, NMFS signed a co-management 
agreement (Agreement) with the ANHSC, a representative body for native 
subsistence users of harbor seals in

[[Page 54793]]

Alaska, in April 1999. The goals of this Agreement include promoting 
the sustained health of harbor seals (Phoca vitulina) in Alaska and the 
culture and way of life of Native Alaskans who rely on the harvest of 
harbor seals for subsistence purposes. In the Agreement, NMFS and the 
ANHSC agreed to identify and resolve, as early as possible, and through 
a consultative process, any conservation issues that may arise 
associated with harbor seals. Over the past two years, the Alaska 
Scientific Review Group (SRG), a regional scientific advisory group 
formed pursuant to the MMPA; the Marine Mammal Commission, a national 
scientific advisory group formed pursuant to the MMPA; and the Alaska 
Harbor Seal Co-management Committee, a group of NMFS and ANHSC advisors 
formed pursuant to the Co-management Agreement, have all raised the 
need to redefine harbor seal stock structure in Alaska.
    Consistent with the provisions of the Agreement, the Co-management 
Committee met in June 2001, to determine how to proceed with reviewing 
and using the newly available results of the genetics studies in a 
management context. The Co-management Committee agreed upon the 
following 3-phase process: (1) to inform all constituents about the 
results and availability of the genetics data; (2) to solicit 
additional input and discuss relevant information such as harbor seal 
abundance, distribution, and movement, as well as traditional and local 
knowledge; and (3) to make recommendations to NMFS regarding the use of 
all appropriate information in revising harbor seal stock structure in 
Alaska.
    The steps identified for this process included peer-review and 
publication of the genetics analysis by NMFS scientists; publication of 
a Federal Register notice to notify interested parties about the 
genetics results and to solicit additional information and viewpoints 
related to the stock structure for harbor seals; and discussion of all 
pertinent information in the co-management process to evaluate and 
revise harbor seal stock structure. The genetics analyses have been 
peer-reviewed at several scientific meetings and the results are in the 
process of being published in technical journals (for more information 
about these analyses, consult the contacts listed under For Further 
Information Contact). Since June 2001, the results of these studies, 
and the process for incorporating these results into the marine mammal 
stock assessment reports, have also been discussed at several SRG 
meetings and at a meeting convened by the Co-management Committee to 
review the harbor seal research plan. The ANHSC also discussed this 
issue at its meeting in Dillingham, Alaska April 29 through May 1, 
2002. NMFS is now publishing this Federal Register notice to solicit 
comments from interested constituents on additional information and 
viewpoints regarding population stock structure of harbor seals in 
Alaska. Following receipt of these comments, NMFS and the ANHSC will 
incorporate all available information, scientific and non-scientific, 
into its discussions and recommendations for a proposed revision to the 
currently recognized harbor seal population stock structure.

Recent Scientific Studies Relevant to Stock Structure

    Following is a summary of recent genetic analyses, telemetry and 
seal movement data, and population trend studies related to Alaska 
harbor seal stock structure.
    Genetics Studies: Recent genetic analyses indicate a much finer 
level of genetic differentiation among Alaska harbor seals than the 
current Stock Assessment Reports indicate, (three harbor seal stocks 
throughout the state). These analyses identify twelve genetically and 
demographically independent groups of seals indicating that a minimum 
amount of movement by seals occurs between or among the following 
areas: the Pribilof Islands; Bristol Bay; Tugidak Island; the northeast 
side of Kodiak Island; the southwest corner of Cook Inlet; the south 
side of the Kenai Peninsula; Prince William Sound; Glacier Bay; the 
inside waters (shielded from the Gulf of Alaska by large islands) of 
northern Southeast Alaska; the outside waters (open to the Gulf of 
Alaska) of northern Southeast Alaska; the inside waters of southern 
Southeast Alaska; and the outside waters of southern Southeast Alaska 
(for a map of these areas see Electronic Access).
    Due to data collection limitations, some areas of the harbor seal's 
range cannot be included in any of the genetic groupings. Therefore, 
these genetic data do not represent all animals or areas in Alaska 
inhabited by harbor seals. However, other scientific data can be used 
to define distinct groups of animals in areas where genetic information 
is lacking. Available telemetry and seal movements data, as well as 
population trend data, for instance, may be used to supplement genetic 
analyses and infer differences among groups of harbor seals in 
different locations.
    Results of Movement and Telemetry Studies: Satellite tagging 
provides useful information on the behavior and ranges of individual 
seals as well as insight into how stocks may be structured. Telemetry 
studies are important because they track movements that suggest the 
locations where harbor seals forage and provide information on 
geographic dispersal. The results of most telemetry studies on harbor 
seals in Alaska indicate that the animals move short distances (less 
than 50 kilometers). In fact, most studies indicate that the majority 
of adult harbor seals remain close to the location where they were 
tagged. For this reason, harbor seals in Alaska are generally 
characterized as non-migratory. The movements of adult seals support 
the conclusion that harbor seals exist in discrete groups among various 
locations.
    The telemetry studies also provide information regarding geographic 
and habitat features that animals do not cross that may represent long-
term barriers to gene flow among groups of seals. For instance, 
extensive tagging data from the Kodiak Archipelago indicate minimal 
movement of harbor seals across Shelikof Strait to the Alaska 
Peninsula, suggesting that this deep-water trench may be an effective 
barrier to harbor seal dispersal.
    Other studies of harbor seal movement patterns suggest that at 
least two additional areas in Alaska may contain harbor seals that are 
discrete from seals in adjacent areas. These two areas include the 
Aleutian Islands west of Unimak Pass and the northeastern Gulf of 
Alaska coast between Cape Suckling and Icy Strait (see Electronic 
Access). Harbor seals in the Aleutian Islands may also be considered 
discrete from seals to the east (on the north side of the Alaska 
Peninsula) based primarily on distance between haulout sites and 
potential oceanographic barriers between this region and the remainder 
of Alaska.
    The Cape Suckling to Icy Strait region of the eastern Gulf of 
Alaska consists of an extensive expanse of open-ocean coastline with 
few haulout sites. The sites that exist in this area are clustered in 
relatively isolated bays and inlets along the coastline that are 
separated from each other by long distances of relatively straight, 
open coastline. Inferences from the telemetry data suggest that seals 
in this region are geographically isolated from other adjacent groups 
of seals.
    Results from Population Trend Analyses: The results of counts at 
population trend-sites throughout the Gulf of Alaska provide additional

[[Page 54794]]

evidence that harbor seals have a finer scale stock structure than the 
current SAR indicates. These counts indicate stable or increasing 
harbor seal numbers in Southeast Alaska, except for Glacier Bay which 
shows a declining trend; several distinct trends in the central Gulf of 
Alaska; and possibly a declining trend in the Bering Sea.
    Southeast Alaska: Trend-sites for the Southeast Alaska stock were 
established in Ketchikan (1983), in Sitka (1984), and in Glacier Bay 
(1992). Current trend data for the Ketchikan trend-sites show an 
increasing trend among harbor seals of 7.4 percent per year (1983-
1998). The Sitka area exhibits a relatively stable trend of 1.1 percent 
per year (1984-1999). Glacier Bay experienced a decreasing trend of -
7.5 percent per year between 1992-98. These trend data indicate that 
Southeast Alaska is likely occupied by more than one discrete harbor 
seal group.
    Gulf of Alaska: The Kodiak Archipelago and Prince William Sound 
represent the principal trend-site areas for the current Gulf of Alaska 
stock of harbor seals. Tugidak Island, in the Kodiak Archipelago, is 
the main long-term trend index site. The Tugidak Island trend-site has 
demonstrated an historical decline of approximately 90 percent from the 
mid-1970s to the 1990s. However, counts at the Tugidak Island site have 
indicated a 6.7 percent per year increase from 1994-1999 during the 
pupping period, and 4.9 percent increase per year during the molting 
period. Recent trend data from the greater Kodiak area (1993-1999) 
suggest an increasing trend of 5.6 percent per year. Overall, however, 
seal abundance in this area remains substantially below abundance 
levels in the 1970s. In Prince William Sound, counts from surveys 
conducted during the harbor seal molt period have declined by 58 
percent since the first trend count surveys were conducted in the early 
1980s. Thus, the population trend data support genetic evidence that 
the Gulf of Alaska is likely to contain more than one stock of harbor 
seals.
    Bering Sea: A trend route was recently established in the eastern 
Bering Sea area along the north side of the Alaska Peninsula in Bristol 
Bay. The Bristol Bay trend route (1998-2001) indicates a declining 
trend of -1.3 percent per year. Total counts of harbor seals in the 
Bering Sea were also obtained in the 1970s and are considerably higher 
than the more recent counts on the Bristol Bay trend-site route. Recent 
population trends (1990-2000) for the land-based trend-site at Nanvak 
Bay indicate an increasing rate of 9.2 percent per year during the 
pupping period and 2.1 percent per year during the molting period. 
Counts in the Bering Sea are complicated by the sympatric ranges of 
harbor seals and spotted seals (P. largha); the two species are 
indistinguishable from aerial surveys.

Request for Comments

    The purposes of this notice are: (1) to inform interested 
constituents that several lines of evidence indicate that harbor seals 
have a finer-scale stock structure in Alaska than current Stock 
Assessment Reports indicate; (2) to advise the public that NMFS and 
ANHSC are evaluating harbor seal stock structure through a co-
management process; and (3) to solicit additional information and 
viewpoints that the public would like NMFS and ANHSC to consider 
throughout the evaluation of harbor seal stock structure.

    Dated: August 19, 2002.
David Cottingham,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 02-21654 Filed 8-23-02; 8:45 am]
BILLING CODE 3510-22-S