Endangered and Threatened Wildlife and Plants: 12-Month Finding for a Petition To List Southern Resident Killer Whales as Threatened or Endangered Under the Endangered Species Act (ESA)

Note: EPA no longer updates this information, but it may be useful as a reference or resource.
 

[Federal Register: July 1, 2002 (Volume 67, Number 126)]
[Proposed Rules]
[Page 44133-44138]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jy02-35]

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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Parts 223 and 224
[Docket No. 020603138-2138-01; I.D. 042502B]
RIN 0648-ZB22
 
Endangered and Threatened Wildlife and Plants: 12-Month Finding 
for a Petition To List Southern Resident Killer Whales as Threatened or 
Endangered Under the Endangered Species Act (ESA)

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.
ACTION: Status review; notice of determination.

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[[Page 44134]]

SUMMARY: NMFS announces a 12-month finding for a petition to list 
Southern Resident killer whales (Orcinus orca) as threatened or 
endangered under the Endangered Species Act (ESA). After a review of 
the best available scientific and commercial information, the agency 
finds that listing the Southern Resident killer whales is not warranted 
at this time because these killer whales do not constitute a species, 
subspecies, or distinct population segment (DPS) under the ESA. NMFS 
will continue to seek new information on the taxonomy, biology, and 
ecology of these whales, as well as potential threats to their 
continued existence, and within 4 years will reassess the status of 
these whales under the ESA. NMFS is issuing an advance notice of 
proposed rulemaking to designate this stock of killer whales as 
depleted under the Marine Mammal Protection Act (MMPA).

DATES: The finding announced in this document was made on May 31, 2002.

ADDRESSES: The complete file for this finding, including comments and 
information submitted, is available for public inspection by 
appointment during normal business hours at the NMFS Protected 
Resources Division, 525 NE Oregon Street, Suite 500, Portland, OR, 
97232-2737.

FOR FURTHER INFORMATION CONTACT: Dr. Thomas Eagle, Office of Protected 
Resources, Silver Spring, MD (301) 713-2322, ext. 105, or Mr. Garth 
Griffin, Northwest Regional Office, Portland, OR (503) 231-2005.

SUPPLEMENTARY INFORMATION:

Electronic Access

    A list of references cited in this notice is available via the 
Internet at http://www.nwr.noaa.gov.  Additional information, including 
the report of the NMFS Biological Review Team (BRT) and written 
comments from the Marine Mammal Commission and other co-managers, is 
also available at this Internet address.

Background

    Section 4(b)(3)(B) of the ESA requires that, for any petition to 
revise the List of Endangered and Threatened Wildlife and Plants that 
presents substantial scientific and commercial information, NMFS must 
make a finding within 12 months of the date of receipt of the petition 
about whether the petitioned action is (a) not warranted, (b) 
warranted, or (c) warranted but precluded from immediate proposal by 
other pending proposals of higher priority. Upon making a 12-month 
finding, the agency must promptly publish notice of such finding in the 
Federal Register.
    On May 2, 2001, NMFS received a petition from the Center for 
Biological Diversity (CBD) and 11 co-petitioners (CBD, 2001a) to list 
Southern Resident killer whales as threatened or endangered and to 
designate critical habitat for them under the ESA. The petitioned 
whales consist of three pods (J, K, and L) whose range during the 
spring, summer, and fall includes the inland waterways of Puget Sound, 
Strait of Juan de Fuca, and Georgia Strait. The primary impetus behind 
the petition is a recent decline in these pods from 97 animals in 1996 
to 78 animals in 2001. The petition highlighted key issues for NMFS' 
consideration, including: (1) Genetic, behavioral, and ecological 
evidence indicating that Southern Resident killer whales may be a DPS 
under the ESA; (2) population data documenting a recent decline in 
Southern Resident killer whales and analyses indicating that these 
whales may be at risk of extinction; and (3) an array of threats that 
may account for the decline in Southern Resident killer whales. On July 
26, 2001, NMFS received additional information from the lead 
petitioner, including an updated population viability analysis and a 
report on the July 2001 census of Southern Resident killer whales 
returning to the inland waters of Washington and southern British 
Columbia (CBD, 2001b).
    On August 13, 2001 (66 FR 42499), NMFS provided notice of its 
determination that the petition presents substantial information 
indicating that a listing may be warranted and that it would initiate a 
status review to determine if Southern Resident killer whales warrant 
listing under the ESA. To conduct the status review, NMFS formed a BRT 
comprising scientists from the agency's Alaska, Northwest, and 
Southwest Fisheries Science Centers. Because the ESA requires that NMFS 
make a listing determination based upon the best available scientific 
and commercial information, the agency solicited pertinent information 
on killer whales (66 FR 42499, August 13, 2001) and convened a meeting 
on September 26, 2001, to gather technical information from co-
managers, scientists, and individuals having research or management 
expertise pertaining to killer whale stocks in the north Pacific Ocean. 
In addition, in March 2002, the BRT received comments from the Marine 
Mammal Commission and Washington, Tribal, and Canadian co-managers on a 
preliminary draft of the BRT's status review findings. These comments 
were evaluated by the BRT, who then prepared a final status review 
document for Southern Resident killer whales (NMFS, 2002). The status 
review and other documents forming the administrative record for this 
finding are available on the Internet (see Electronic Access) or from 
NMFS (see ADDRESSES).

Biological Background

    Killer whales are one of the most strikingly pigmented of all 
cetaceans, making field identification easy. Killer whales are black 
dorsally and white ventrally, with a conspicuous white oval patch 
located slightly above and behind the eye. A highly variable gray or 
white saddle is usually present behind the dorsal fin. Saddle shape 
varies among individuals, pods, and from one side to the other on a 
single animal. Sexual dimorphism occurs in body size, flipper size, and 
height of the dorsal fin. More detailed information regarding this 
species' distribution, behavior, genetics, morphology, and physiology 
is contained in the BRT's status review (NMFS, 2002).
    Killer whales are classified as top predators in the food chain and 
the world's most widely distributed marine mammal (Leatherwood and 
Dahlheim, 1978; Heyning and Dahlheim, 1988). Although observed in 
tropical waters and the open sea, they are most abundant in coastal 
habitats and high latitudes. In the northeastern Pacific Ocean, killer 
whales occur in the eastern Bering Sea (Braham and Dahlheim, 1982) and 
are frequently observed near the Aleutian Islands (Scammon, 1874; 
Murie, 1959; Waite et al., 2001). They reportedly occur year-round in 
the waters of southeastern Alaska (Scheffer, 1967) and in the 
intracoastal waterways of British Columbia and Washington State 
(Balcomb and Goebel, 1976; Bigg et al., 1987; Osborne et al., 1988). 
There are occasional reports of killer whales along the coasts of 
Washington, Oregon, and California (Norris and Prescott, 1961; Fiscus 
and Niggol, 1965; Rice, 1968; Gilmore, 1976; Black et al., 1997), both 
coasts of Baja California (Dahlheim et al., 1982), the offshore 
tropical Pacific (Dahlheim et al., 1982), the Gulf of Panama, and the 
Galapagos Islands. In the western North Pacific, killer whales occur 
frequently along the Soviet coast in the Bering Sea, the Sea of 
Okhotsk, the Sea of Japan, and along the eastern side of Sakhalin and 
the Kuril Islands (Tomilin, 1957). There are numerous accounts of their 
occurrence off China (Wang, 1985) and Japan (Nishiwaki and Handa, 1958; 
Kasuya, 1971; Ohsumi, 1975). Data from the central Pacific are scarce. 
They have been reported off

[[Page 44135]]

Hawaii, but do not appear to be abundant in these waters (Tomich, 1986; 
Caretta et al., 2001).
    The killer whale is the largest species within the family 
Delphinidae. Various scientific names have been assigned to the killer 
whale (Hershkovitz, 1966; Heyning and Dahlheim, 1988). These various 
names can be explained by sexual and age differences in the size of the 
dorsal fin, individual variations in color patterns, and the 
cosmopolitan distribution of the animals. The genus Orcinus is 
currently considered monotypic with geographical variation noted in 
size and pigmentation patterns. Two proposed Antarctic species, O. 
nanus (Mikhalev et al., 1981) and O. glacialis (Berzin and Vladimirov, 
1982; Berzin and Vladimirov, 1983), both appear to refer to the same 
type of smaller individuals. However, due to significant uncertainties 
regarding the limited specimen data, these new taxa have not yet been 
widely accepted by the scientific community. Recent genetic 
investigations note marked differences between some forms of killer 
whale (Hoelzel and Dover, 1991; Hoelzel et al., 1998; Barrett-Lennard, 
2000; Barrett-Lennard and Ellis, 2001). A worldwide review of specimens 
is needed to document geographical variation in morphology.
    Killer whales in the Eastern North Pacific region (which includes 
the petitioned whale pods) have been classified into three forms termed 
Residents, Transients, and Offshore whales. The three forms vary in 
morphology, ecology, behavior, and genetic characteristics, all of 
which play an important role in determining whether the monotypic 
species O. orca can be subdivided under the ESA.

Resident Killer Whales

    Resident killer whales in the Eastern North Pacific are noticeably 
different from both the Transient and Offshore forms. The dorsal fin of 
Resident whales is rounded at the tip and falcate (curved and 
tapering). Resident whales have a variety of saddle patch 
pigmentations, with five different patterns recognized (Baird and 
Stacey, 1988a). Resident whales occur in large, stable pods with 
membership ranging from 10 to approximately 60 whales. Their presence 
has been noted in the waters from California to Alaska. The primary 
prey of Resident whales is fish. A recent summary of the differences 
between Resident and Transient forms is found in Baird (2000).
    Resident killer whales in the North Pacific consist of the 
following groups: Southern, Northern, Southern Alaska, western Alaska 
and western North Pacific Residents. Under the Marine Mammal Protection 
Act (MMPA), Residents are separated into two stocks: (1) The eastern 
North Pacific southern resident stock, which is the petitioned unit and 
(2) the eastern North Pacific northern resident stock, which includes 
the Northern (British Columbia) Residents, the Southern Alaska 
Residents, and the western Alaska Residents. The descriptions of the 
various units follows.
    Southern Residents: The Southern Resident killer whale assemblage 
contains three pods, J pod, K pod, and L pod, and is considered a stock 
under the MMPA. Their range during the spring, summer, and fall 
includes the inland waterways of Puget Sound, Strait of Juan de Fuca, 
and Georgia Strait. Their occurrence in the coastal waters off 
Washington, Vancouver Island, and more recently off the coast of 
central California has been documented. Little is known about the 
winter movements and range of the Southern Resident stock. Southern 
Residents have not been seen to associate with other Resident whales. 
Genetic data indicate that females from the Southern and Northern 
Resident populations have not been migrating between populations within 
at least the recent evolutionary history of these populations, 
suggesting reproductive isolation between Southern and Northern 
Resident killer whale stocks (Hoelzel et al., 1998; Barrett-Lennard, 
2000; Barrett-Lennard and Ellis, 2001).
    Northern Residents: The Northern Resident killer whale assemblage 
contains approximately 16 pods. They range from Georgia Strait (British 
Columbia) to Southeast Alaska (Ford et al., 1994; Dahlheim, 1997). On 
occasion they have been known to occur in Haro Strait (west of San Juan 
Island, Washington). Although some overlap in range occurs between the 
Northern and Southern Residents, no intermixing of pods has been noted. 
However, in Southeast Alaska, Northern Resident whales are known to 
associate with Southern Alaska Residents (Dahlheim et al., 1997), and 
there may be some gene flow between the two populations (Hoelzel et 
al., 1998; Barrett-Lennard, 2000; Barrett-Lennard and Ellis, 2001).
    Alaska Residents: There are two groups of Alaska Resident animals, 
Southern Alaska Residents and western Alaska Residents. The Resident 
whales of Southeast Alaska and Prince William Sound comprise the 
Southern Alaska Resident killer whale assemblage. At least 15 pods have 
been identified in these two regions. Resident killer whales 
photographed in Southeast Alaska travel frequently to Prince William 
Sound and intermix with all Resident groups from this area (Dahlheim et 
al., 1997; Matkin and Saulitis, 1997). Prince William Sound Resident 
whales have not been seen in Southeast Alaska, but have been noted off 
Kodiak Island intermixing with other, yet unnamed, Resident pods 
(Dahlheim, 1997; National Marine Mammal Laboratory, 2001). There are 
241 animals photographed in western Alaska that have been provisionally 
identified as ``Western Alaska Residents,'' but the number of pods 
represented is unknown (National Marine Mammal Laboratory, 2001). 
Recent vessel surveys in the southeastern Bering Sea have provided 
preliminary estimates of approximately 400 killer whales (Waite et al., 
2001). Although it is not yet known how many of these animals were 
Residents, killer whales occur both nearshore and offshore in the 
Bering Sea.
    Western North Pacific Residents: Resident killer whales co-occur 
with salmon along the coasts of Washington, British Columbia, and 
Alaska. If this pattern continues (or historically continued) further 
to the west, then Resident killer whales may be expected to occur along 
the coastline of Russia and Japan. Although there is documentation of 
killer whales in these areas, little is known about whether they are 
more similar to Resident, Transient, or Offshore types.

Transient Killer Whales

    There are several differences between Transient and Resident killer 
whales; these have most recently been summarized in Baird (2000). The 
dorsal fin of Transient whales tends to be more erect (i.e., straighter 
at the tip) than those of Resident and Offshore whales. Saddle patch 
pigmentation of Transient killer whales is restricted to three patterns 
(Baird and Stacey, 1988a). Pod structure is small (e.g., fewer than 10 
whales) and dynamic in nature. Transient whales occur throughout the 
Eastern North Pacific with a preference toward coastal waters. Their 
geographical range overlaps that of the Resident and Offshore whales. 
Individual Transient killer whales have been documented to move great 
distances reflecting a large home range (Goley and Straley, 1994; 
National Marine Mammal Laboratory, 2001). The primary prey of Transient 
killer whales is other marine mammals. Transient whales are not known 
to intermingle with Resident or Offshore whales. Significant genetic 
differences occur among Resident, Transient, and Offshore killer whales 
(Stevens et al., 1989; Hoelzel and Dover, 1991; Hoelzel

[[Page 44136]]

et al., 1998; Barrett-Lennard, 2000; Barrett-Lennard and Ellis, 2001). 
At this time, only one stock of Transient killer whales is recognized 
in eastern North Pacific waters, although recent genetic investigations 
indicate that up to three genetically different groups of Transient 
killer whales exist in the eastern North Pacific (the ``west coast'' 
Transients, the ``Gulf of Alaska Transients'' and AT1 pod) (Barrett-
Lennard, 2000; Barrett-Lennard and Ellis, 2001).

Offshore Killer Whales

    Offshore killer whales are similar to Resident whales (i.e., their 
fins appear to be more rounded at the tip). Most saddle patches appear 
to be closed (National Marine Mammal Laboratory, 2001). Offshore whales 
have been seen in groups ranging from 10 to 70 whales. They are known 
to range from central coastal Mexico to Alaska and occur in both 
coastal and offshore waters (300 miles off Washington State). While 
foraging, it is assumed that the main target is fish, but observational 
data on feeding events are extremely limited. Offshore whales are not 
known to intermingle with Resident or Transient whales. Genetic 
analysis suggests that Offshores may be reproductively isolated, but 
they appear to be more closely related to Southern Residents than to 
Northern Residents (Hoelzel et al., 1998).

Consideration as a ``Species'' Under the ESA

    The ESA defines a species to include ``any subspecies of fish or 
wildlife or plants, and any distinct population segment of any species 
of vertebrate fish or wildlife which interbreeds when mature.'' 
Guidance on what constitutes a DPS is provided by the joint NMFS-U.S. 
Fish and Wildlife Service interagency policy on vertebrate populations 
(61 FR 4722, February 7, 1996). To be considered a DPS, a population, 
or group of populations, must be ``discrete'' from other populations 
and ``significant'' to the taxon (species or subspecies) to which it 
belongs. A population segment of a vertebrate species may be considered 
discrete if:
    (1) It is markedly separated from other populations of the same 
taxon as a consequence of physical, physiological, ecological or 
behavioral factors. Quantitative measures of genetic or morphological 
discontinuity may also provide evidence of this separation; or
    (2) It is delimited by international governmental boundaries within 
which differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant under section 4(a)(1)(D) of the ESA.
    If a population segment is considered discrete, NMFS must then 
consider whether the discrete segment is ``significant'' to the taxon 
to which it belongs. Criteria that can be used to determine whether the 
discrete segment is significant include:
    (1) Persistence of the discrete population segment in an ecological 
setting unusual or unique for the taxon;
    (2) Evidence that loss of the discrete population segment would 
result in a significant gap in the range of the taxon;
    (3) Evidence that the discrete population segment represents the 
only surviving natural occurrence of a taxon that may be more abundant 
elsewhere as an introduced population outside its historical range; and
    (4) Evidence that the discrete population segment differs markedly 
from other populations of the species in its genetic characteristics.
    A population segment needs to satisfy only one of these criteria to 
be considered significant. Furthermore, the list of criteria is not 
exhaustive; other criteria may be used, as appropriate. As noted in the 
DPS policy, Congress has instructed NMFS and the U.S. Fish and Wildlife 
Service to use the authority to list a DPS ``sparingly and only when 
the biological evidence indicates such action is warranted'' (Senate 
Report 151, 96th Congress, 1st Session (1979)).

Defining a DPS Under Existing Killer Whale Taxonomy

    Two types of genetic data that have been collected for killer 
whales have proven useful for identifying DPS boundaries in other 
species: microsatellite (nuclear) DNA and mitochondrial DNA (mtDNA). 
Each type of genetic data offers a unique and valuable perspective on 
the ecology and evolutionary history of killer whales. Microsatellite 
data are available for killer whales from seven populations: Southern 
Residents, Northern Residents, Southern Alaskan Residents, Gulf of 
Alaska Transients, west coast Transients, and AT1 Transients from 
Prince William Sound in Alaska. The magnitude of the genetic 
differences between Southern and Northern Residents was about half that 
found between Residents and Transients and about twice that found 
between Northern Residents and Southern Alaska Residents. These 
differences indicate that the Southern Resident, Northern Resident, and 
Alaska Resident populations are reproductively isolated populations and 
that the isolation of Southern and Northern Residents from each other 
is greater than the isolation between Northern and Southern Alaska 
Residents. There may be some gene flow between the Northern Residents 
and Southern Alaska Residents (Hoelzel et al., 1998; Barrett-Lennard, 
2000; Barrett-Lennard and Ellis, 2001).
    Two mtDNA sequences have been found in North Pacific Resident 
killer whales. The Southern Residents have one sequence and the 
Northern Residents have another that differs by one DNA nucleotide. 
Southern Alaska Residents have both sequences. Both males and females 
inherit the mtDNA of their mother, so these data indicate that females 
from the Southern and Northern Resident populations have not been 
migrating between populations within at least the recent evolutionary 
history of these populations.
    The BRT recommended that Southern Residents meet the criterion for 
``discreteness'' under the DPS policy based on genetics and other 
information. However, the consideration of ``significance'' was far 
more difficult, largely due to uncertainties surrounding killer whale 
taxonomy. Correctly identifying the killer whale taxon is critical 
because the criteria used to evaluate ``significance'' of a DPS are 
defined relative to other populations within that taxon. The BRT 
concluded that the current designation of one global species for killer 
whales is likely inaccurate because available data suggest that 
additional species/subspecies of killer whales probably exist.
    In its consideration of ``significance,'' the BRT evaluated the 
importance of Southern Residents to the taxon represented by the 
currently recognized global species, O. orca. Based upon the following 
arguments, the BRT concluded that Southern Resident killer whales are 
not a DPS of the global species.
    Persistence in an ecological setting that is unusual or unique for 
the taxon. The habitat used by Southern Resident killer whales is very 
similar to that of the neighboring Northern Resident population segment 
(coastal fjord system, significant freshwater input, seasonal 
availability of concentrations of salmon) though different from 
habitats that other populations of killer whales occupy globally. In 
addition, although Southern and Northern/Alaska Residents consume 
salmon from different oceanographic systems, this difference is quite 
minor when comparing Southern Resident killer whales foraging 
strategies with other killer whale foraging strategies on a global 
scale.
    The petitioners suggested that Southern Resident killer whales 
occupy

[[Page 44137]]

a unique setting because the Puget Sound region is highly urbanized. 
Based upon the recommendation of the BRT, NMFS finds that this habitat 
difference is irrelevant to the ESA discussion because there is no 
evidence that Southern Residents have adapted in an evolutionary sense 
to urbanization in Puget Sound.
    Loss would represent a significant gap in the range of the taxon. 
Because Transient killer whales are known to occupy the same range as 
Southern Resident killer whales and because Offshore killer whales may 
occupy a portion of the same range as Southern Resident killer whales, 
extinction of Southern Resident killer whales might not result in a gap 
in the range of the taxon. In addition, other Resident or Offshore 
animals could re-colonize the current range of Southern Residents 
should that population be extirpated.
    Although it is plausible that the loss of Southern Resident killer 
whales could result in few, if any, killer whales in parts of Puget 
Sound for an extended period, killer whales would occupy their existing 
range from the Bering Sea through British Columbia. Furthermore, 
Transient and Offshore pods would continue to occupy other areas within 
the Pacific Ocean. NMFS, therefore, concluded that the potential gap 
that could result in the loss of Southern Residents would not be 
considered ``significant'' to the species.
    The only surviving natural occurrence of a taxon. Because Southern 
Resident killer whales are clearly not a ``discrete population segment 
representing the only surviving natural occurrence of a taxon that may 
be more abundant elsewhere as an introduced population outside its 
historic range,'' the BRT did not consider this criterion from the DPS 
policy.
    Evidence that the Southern Residents differ markedly from other 
populations in genetic characteristics. The BRT evaluated the genetic 
discreteness of Southern Resident killer whales in the context of 
genetic differences among all aggregations of killer whales globally. 
It found that the differences between Southern Residents and Resident 
pods in Canada and Alaska were small compared to genetic differences 
between Resident and Transient killer whale stocks. Consequently, the 
Southern Resident killer whale stock does not have markedly different 
genetic characteristics.

Southern Residents as a DPS Under Alternative Killer Whale Taxa

    Although the BRT concluded that current killer whale taxonomy was 
outdated, the scientists acknowledged that alternative taxa were not 
easily identified and noted that formal taxonomic changes would be slow 
to occur. In light of this, the BRT assessed which of several 
population units of killer whales might be designated as a putative 
taxon that would include Southern Resident killer whales if the global 
species were to be subdivided into two or more taxa.
    The BRT supported about equally four different scenarios for 
alternative taxa: (1) North Pacific Resident killer whales; (2) North 
Pacific Resident and Offshore killer whales; (3) fish-eating killer 
whales worldwide; and (4) the entire mtDNA lineage that includes 
Resident and Offshore type killer whales. Despite the broad range of 
possible alternative taxa, the BRT did attempt to discern whether the 
Southern Resident population would qualify as a DPS with respect to 
each of these alternative taxonomic scenarios. Such information would 
be deemed useful if future changes in this species' taxonomy warranted 
reconsidering the ESA/DPS status of Southern Resident killer whales.
    Within these four scenarios, the BRT expressed the strongest 
support for the proposition that Southern Residents would be a DPS of 
the Northern Pacific Residents (which included Southern, Northern, 
Alaska, and western North Pacific Resident killer whales). Support for 
Southern Residents as their own DPS diminished as the hypothesized 
taxon grew larger.

Risk Assessment Under Alternative Taxa

    Upon concluding that the petitioned entity-Southern Resident killer 
whale-is not a DPS of the smallest taxon identified by the scientific 
community (i.e., the global species), the BRT could have ended its 
investigation. However, because the team members believed that current 
killer whale taxonomy is outdated, they continued their assessment 
beyond the narrow focus of the petition. Therefore, the BRT also 
investigated Southern Residents as a component of several potential 
DPS, and they examined various putative taxa of which Southern 
Residents would be a DPS. Then, the BRT conducted Population Viability 
Analyses (PVA) to estimate the probability of extinction for two of the 
smallest possible population units.
    The first scenario analyzed was one for Southern Resident killer 
whales alone. As a continuation of the BRT's alternative taxa 
deliberations, this information would be considered useful if future 
changes in this species' taxonomy warranted reconsidering the ESA/DPS 
status of Southern Resident killer whales. According to the PVA model 
results, Southern Residents would have a £10 percent 
probability of extinction in 100 years under the assumption that 
population declines seen from 1992 to 2001 continue into the future. 
Under the assumption that growth rates in the future would more 
accurately be predicted by the full (27-year) time series of data 
available, the model predicts that extinction probability is 1 to 5 
percent in 100 years, with the higher values associated with higher 
probability and magnitude of catastrophic mortality events (e.g., oil 
spill). Again, these results pertain only to the smallest population 
assemblage containing Southern Residents, not to a recognized DPS. As 
such, they represent ``worst case'' estimates that are intended for 
comparison with other, larger aggregations.
    The second scenario evaluated the extinction risk of a combination 
of Southern Residents and the closest population stock (identified 
under the MMPA), which is the eastern North Pacific Northern Resident 
stock (resident killer whales in British Columbia and Alaska). 
According to the model, the extinction risk over 100 years for this 
larger assemblage is negligible, and even larger aggregations are 
expected to yield similarly negligible extinction risks. Therefore, 
additional simulations were not conducted.

Conclusions of the BRT

    Correctly identifying the killer whale taxon is critical because at 
least two of the criteria used to evaluate ``significance'' of a DPS 
are defined relative to other populations within that taxon. A 
population segment will qualify as a DPS if it occupies an ``ecological 
setting unusual or unique for the taxon'' or if ``loss of the discrete 
population segment would result in a significant gap in the range of 
the taxon.'' The BRT concluded that the current designation of one 
global species for killer whales is likely inaccurate because available 
data suggest that present taxonomy does not reflect current knowledge 
and additional species/subspecies of killer whales should be 
``officially'' recognized.
    The BRT attempted to identify alternative taxa, but gave roughly 
equal support to four different scenarios. The taxon to which Southern 
Residents might belong if the global species were to be subdivided 
could be as small as North Pacific Resident killer whales or as large 
as the mtDNA lineage consistent with fish eating whales. The BRT

[[Page 44138]]

conducted PVA modeling on two population units of killer whales, 
Southern Residents along and in combination with Northern and Alaska 
Residents for comparative purposes. Although Southern Residents are not 
considered a DPS of the global species, they face a relatively high 
risk of extinction. The combination of Southern, Northern, and Alaska 
Residents, however, was at a very low risk of extinction. Thus, the 
manner by which killer whale taxonomy is resolved in the future will 
play a key role in determining whether there is a DPS to which Southern 
Resident killer whales belong and in evaluating the status of that DPS 
under the ESA.
    As described previously in this notice, NMFS received comments on a 
preliminary draft of the BRT's status review findings from the Marine 
Mammal Commission and from Washington, Tribal, and Canadian co-
managers. These comments included technical questions and data (e.g., 
recent census data for Northern Resident whales), discussions of DPS 
and listing policy issues, and information describing the cultural and 
spiritual importance of killer whales to Native American Tribes.
    Some co-managers requested that NMFS use other DPS criteria for 
significance, such as the ecological role of Southern Resident killer 
whales in Puget Sound and Georgia Straits. The BRT discussed an array 
of criteria that may be useful for determining significance, including 
some not contained in the DPS policy but raised by the petitioners or 
co-managers. However, only the criteria described in the DPS policy 
were deemed applicable to assessing the significance of Southern 
Residents. Based on these criteria, the BRT concluded that Southern 
Resident killer whales are not a DPS of the global species. The 
criteria before the BRT for considering ``significance'' were 
sufficient to evaluate whether or not Southern Residents represented a 
DPS of killer whales. In the notice of joint policy regarding DPS 
determinations (61 FR 4722, February 7, 1996), NMFS and the U.S. Fish 
and Wildlife Service discussed the criteria for evaluating a portion of 
a species as a DPS. The Services noted that the ESA is not intended to 
establish a comprehensive biodiversity conservation program; rather, 
the ESA is focused on the protection and recovery of threatened and 
endangered species or population segments that are discrete and 
significant to the species and on the ecosystems upon which these 
particular species depend. In the 1996 policy notice, the Services 
responded to a comment suggesting that the ``significance'' criteria 
include a consideration of the affected population's importance to the 
ecosystem it occupies. The Services noted that most, if not all, 
populations play a significant role in their ecosystems. The Services 
also stated, ``On the other hand, populations commonly differ in their 
importance to the overall welfare of the species they represent, and it 
is this importance that the (DPS) policy attempts to reflect in the 
consideration of significance.'' NMFS concurs with other co-manager 
comments that the issue of classifying Southern Resident killer whales 
into a particular DPS cannot be resolved until the taxonomic structure 
of O. orca is clarified.

Finding

    NMFS has reviewed the petition, the report of the BRT (NMFS, 2002), 
co-manager comments, and other available information, and has consulted 
with species experts and other individuals familiar with killer whales. 
On the basis of the best available scientific and commercial 
information, the agency finds that the petitioned action is not 
warranted at this time because the petitioned group of killer whales 
does not constitute a DPS of the currently recognized species O. orca.
    The status review revealed uncertainties regarding the taxonomic 
status of killer whales worldwide. The taxonomy of killer whales that 
is currently published in the scientific literature includes a single 
species that includes all killer whales globally. The BRT discussed 
more recent, but inconclusive, evidence that O. orca could be separated 
from a single, global species into additional species or subspecies. In 
this case, NMFS recognized that taxonomists may be conservative or 
liberal in assigning new species and that the relevance of new 
information may be debated widely before it is generally accepted by 
the scientific community. Because the recent information related to the 
taxonomy of killer whales has not been subjected to that scientific 
debate, NMFS considers the published standard of a single, global 
species as the best available scientific information. In accordance 
with the report of the BRT, NMFS finds that Southern Resident killer 
whales are not a ``species'' under the ESA. Consequently, NMFS finds 
that listing Southern Resident killer whales as threatened or 
endangered is not warranted at this time.
    As noted in the report of the BRT, NMFS also investigated 
alternatives to identify whether there is a DPS to which Southern 
Residents may belong. Although a DPS could not be identified clearly, 
the BRT evaluated the risk of extinction of other larger potential DPSs 
by aggregating logical units. For a first logical step in aggregating 
units of killer whales, the BRT combined the Southern, Northern, and 
Alaska Residents and simulated the risk of extinction for this 
aggregation. Simulation results predicted that the extinction risk of 
that initial aggregation was negligible. Therefore, NMFS cannot 
identify a DPS to which Southern Residents may belong that is in danger 
of extinction throughout all or a significant portion of its range or 
likely to become endangered in the foreseeable future.
    NMFS is, however, concerned about the recent decline in the 
Southern Resident assemblage, and will continue to seek new information 
on the taxonomy, biology, and ecology of these whales, as well as 
potential threats to their continued existence. Within 4 years, NMFS 
will reconsider the taxonomy of killer whales. If the species O. orca 
has been subdivided in a manner that may allow Southern Resident killer 
whales to be identified as a DPS, NMFS will reconvene a BRT to reassess 
the status of these whales under the ESA. Also, in light of new 
information presented in the recently completed status review and in 
response to some co-manager recommendations, the agency will review the 
status of Southern Resident killer whales to determine whether they 
warrant reclassification as a depleted stock under the MMPA. A request 
for information relevant to making this latter determination is being 
made via a concurrent notice in the Federal Register.

References

    A complete list of all cited references is available on the 
Internet (see Electronic Access) or from NMFS upon request (see FOR 
FURTHER INFORMATION CONTACT).

    Dated: June 7, 2002.
William T. Hogarth,
Assistant Administrator for Fisheries, National Marine Fisheries 
Service.
[FR Doc. 02-16526 Filed 6-28-02; 8:45 am]
BILLING CODE 3510-22-S
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Endangered and Threatened Wildlife and Plants: 12-Month Finding for a Petition To List Southern Resident Killer Whales as Threatened or Endangered Under the Endangered Species Act (ESA)

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