[Federal Register Volume 70, Number 108 (Tuesday, June 7, 2005)]
[Notices]
[Pages 33116-33122]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-11210]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[Docket No. 040511147-5142-02; I.D. 042804B]
Listing Endangered and Threatened Species and Designating
Critical Habitat: 12-Month Finding on Petition to List the Cherry Point
Stock of Pacific Herring as an Endangered or Threatened Species
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of 12-month petition finding.
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SUMMARY: We (NMFS) have completed an updated Endangered Species Act
(ESA) status review of Pacific herring (Clupea pallasi), inclusive of
the Cherry Point herring stock (Strait of Georgia, Washington). We
initiated this status review update in response to a petition received
on May 14, 2004, to list the Cherry Point stock of Pacific herring as a
threatened or endangered species. We have determined that the Cherry
Point herring stock does not qualify as a ``species'' for consideration
under the ESA. Based upon the best available
[[Page 33117]]
scientific and commercial information, we conclude that the petitioned
action to list the Cherry Point Pacific herring stock as a threatened
or endangered species is not warranted. We find that the Cherry Point
stock is part of the previously defined Georgia Basin distinct
population segment (DPS) composed of inshore Pacific herring stocks
from Puget Sound (Washington) and the Strait of Georgia (Washington and
British Columbia). We have determined that the Georgia Basin DPS of
Pacific herring is not in danger of extinction or likely to become
endangered in the foreseeable future throughout all or a significant
portion of its range, and therefore does not warrant ESA listing at
this time.
DATES: The finding announced in this notice was made on June 1, 2005.
ADDRESSES: The status review update for Pacific herring and the list of
references cited in this notice are available upon request from Chief,
NMFS, Protected Resources Division, 1201 NE Lloyd Avenue, Suite 1100,
Portland, OR, 97232. These materials are also available on the Internet
at: http://www.nwr.noaa.gov.
FOR FURTHER INFORMATION CONTACT: For further information regarding this
notice contact Garth Griffin, NMFS, Northwest Region, (503) 231-2005,
or Marta Nammack, NMFS, Office of Protected Resources, (301) 713-1401.
SUPPLEMENTARY INFORMATION:
Background
ESA Statutory Provisions and Policy Considerations
Under the ESA, a listing determination may address a species,
subspecies, or a DPS of any vertebrate species which interbreeds when
mature (16 U.S.C. 1532(15)). On February 7, 1996, the U.S. Fish and
Wildlife Service and NMFS adopted a policy to clarify the agencies'
interpretation of the phrase ``distinct population segment of any
species of vertebrate fish or wildlife'' (ESA section 3(15)) for the
purposes of listing, delisting, and reclassifying a species under the
ESA (51 FR 4722). The joint DPS policy identified two elements that
must be considered when making DPS determinations: (1) the discreteness
of the population segment in relation to the remainder of the species
(or subspecies) to which it belongs; and (2) the significance of the
population segment to the remainder of the species (or subspecies) to
which it belongs.
Section 3 of the ESA defines an endangered species as ``any species
which is in danger of extinction throughout all or a significant
portion of its range,'' and a threatened species as one ``which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range.'' The statute
lists factors that may cause a species to be threatened or endangered
(ESA section 4(a)(1)): (a) the present or threatened destruction,
modification, or curtailment of its habitat or range; (b)
overutilization for commercial, recreational, scientific, or
educational purposes; (c) disease or predation; (d) the inadequacy of
existing regulatory mechanisms; or (e) other natural or manmade factors
affecting its continued existence.
Section 4(b)(1)(A) of the ESA requires NMFS to make listing
determinations based solely on the best scientific and commercial data
available after conducting a review of the status of the species and
after taking into account efforts being made to protect the species. In
making listing determinations under the ESA we first determine whether
a population or group of populations constitutes a DPS (i.e., whether
the populations(s) should be considered a ``species'' within the
meaning of the ESA), and if so we assess the level of extinction risk
faced by the DPS and any factors that have led to its decline. If it is
determined that the DPS' survival is at risk throughout all or a
significant portion of its range, we then assess efforts being made to
protect the species, determining if these efforts are adequate to
mitigate threats to the species. Based on the foregoing information and
the factors identified in ESA section 4(a)(1), we then make a listing
determination of whether the species is threatened, the species is
endangered, or listing is not warranted.
Life History of Pacific Herring
Pacific herring in the Eastern Pacific Ocean range from northern
Baja California north to at least the Mackenzie Delta in the Beaufort
Sea. They are also found in the Russian Arctic from the Chukchi Sea in
the east to the White Sea in the west, although the boundary between
Atlantic and Pacific herring is unclear in this region (Hay et al.,
2001b). In the Northwestern Pacific they are found throughout the
Western Bering Sea, the east coast of Kamchatka, and the Sea of
Okhotsk; on the east and west coasts of Hokkaido, Japan; and south and
west to the Yellow Sea off the Korean Peninsula (Haegele and
Schweigert, 1985; Hay et al., 2001b).
Adult herring in the Eastern Pacific move inshore during winter and
early spring and reside in holding areas before moving to adjacent
spawning grounds (Hay, 1985). Spawning grounds are typically in
sheltered inlets, sounds, bays, and estuaries (Haegele and Schweigert,
1985). Pacific herring usually spawn intertidally or in shallow
subtidal zones, depositing adhesive eggs over algae, vegetation, or
other substrates (Hay, 1985). The location and timing of spawning for
individual stocks are generally consistent and predictable from year to
year (Hay et al., 1989; O'Toole et al., 2000).
Pacific herring spawn timing varies with latitude, with earlier
spawning (i.e., early-winter) occurring in the more southern latitudes
of the species' range, and later spawning (i.e., mid-summer) occurring
toward the northern limit of the species' range (Hay, 1985). In Puget
Sound, spawning generally occurs from January to April, with peak
spawning activity in February and March; however, Pacific herring at
Cherry Point spawn from late-March to mid-June (Bargmann, 1998).
Pacific herring larvae drift in ocean currents after hatching and
are abundant in shallow nearshore waters (Lassuy, 1989; Hay and
McCarter, 1997). After 2 to 3 months, larvae metamorphose into
juveniles that form large schools and remain primarily in nearshore
shallow-water areas during the first summer. After their first summer,
juveniles may disperse to deeper offshore waters to mature or reside
year-round in nearshore waters (Hay, 1985). For example, some herring
are nonmigratory or resident and spend their entire life within Puget
Sound and the Strait of Georgia, while other more migratory herring
spend their summers in the offshore waters of Washington and southern
British Columbia (Hay et al., 2001a; Trumble, 1983).
Pacific herring age at first maturity ranges from age-2 to age-5
(Hay, 1985). Along the west coast of North America, populations of
Pacific herring exhibit a latitudinal cline in age at first maturity,
such that herring in southern locations (i.e., California) mature at an
earlier age and herring in the north (i.e., Bering Sea) mature at later
ages (Hay, 1985). In Puget Sound, Pacific herring reach sexual maturity
at age-2 to age-4 (Bargmann, 1998). Pacific herring in the Strait of
Georgia and other major assessment areas in British Columbia reach
sexual maturity at age-3 (Hay and McCarter, 1999). In general,
populations of Pacific herring also exhibit a latitudinal cline in mean
size-at-age, such that herring in southern locations (i.e., California)
exhibit small size and herring in the north (i.e., Bering Sea) attain a
far larger size at a similar age. Herring may spawn annually for
several years (Hay, 1985), with overall
[[Page 33118]]
fecundity increasing as body size increases (Ware, 1985; Hay, 1985).
In the state of Washington there are 21 documented spawning stocks:
19 stocks in Puget Sound (including the Cherry Point stock and the
recently re-discovered Wollochet Bay stock), and two on the Washington
Coast (Bargmann, 1998; Stout et al., 2001). The Cherry Point Pacific
herring stock historically spawned along the Washington coastline from
Hale Passage (between the north end of Bellingham Bay and the east
coast of Lummi Island), north to Cherry Point, Birch Point, Point
Roberts, and the border with Canada (Lemberg et al., 1997). Since 1996,
spawning of the Cherry Point stock has only occurred in the vicinity of
Birch Point and along the Cherry Point Reach. Spawning at Cherry Point
can begin as early as late-March and end as late as mid-June, although
peak spawning activity occurs around May 10th (O'Toole et al., 2000).
Spawning at all other Pacific herring locations in Puget Sound, Hood
Canal, and the Strait of Juan de Fuca normally occurs from late-January
through late-April (Trumble, 1983; Lemberg et al., 1997; O'Toole et
al., 2000) with peak spawning starting the last week of February or the
first week of March (O'Toole et al., 2000).
Since record keeping began in 1928, British Columbia Pacific
herring have been observed to spawn at over 1,300 locations along the
approximately 5,200 km of coastline that is classified as herring
spawning habitat (Hay and McCarter, 2004). In any given year, between
450 and 600 km of the British Columbia coast receives herring spawn.
The Canada Department of Fisheries and Oceans has identified six stock
assessment regions and 101 sub-areas or ``Herring Sections''
characterized by consistent Pacific herring spawning activity. In
general, Pacific herring spawn from January to May in southern British
Columbia and from mid-January to June in northern British Columbia
(Taylor, 1964; Hourston, 1980). As at Cherry Point, Pacific herring in
several Herring Sections in British Columbia exhibit notably late spawn
timing for their local region (e.g., Skidegate Inlet [Section 022] and
Masset Inlet [Section 011] in the Queen Charlotte Islands Region and
Burke Channel [Section 084] in the Central Coast Region) (Hay et al.,
1989).
Previous Federal Actions Relating to Pacific Herring
We completed a status review of Pacific Herring in 2001 (Stout et
al., 2001). This earlier review was initiated in response to a petition
received in February 1999 to list 18 species of marine fishes in Puget
Sound, including Pacific herring. We concluded that the Pacific herring
stocks in Puget Sound do not constitute a DPS (and therefore do not
qualify as a ``species'' under the ESA). We determined that these Puget
Sound herring stocks, including the Cherry Point stock, belonged to a
larger Georgia Basin Pacific herring DPS consisting of over 40 inshore
stocks from Puget Sound and the Strait of Georgia in the United States
and Canada (64 FR 17659; April 3, 2001). We concluded that the Georgia
Basin DPS is not threatened or endangered throughout all or a
significant portion of its range (64 FR 17659; April 3, 2001); however,
we did note concern regarding two herring stocks within the Georgia
Basin DPS (the Cherry Point and Discovery Bay stocks) that have shown
marked declines in range and abundance. Although we recognized that
these two declining stocks may be vulnerable to extirpation, we
concluded that they represent a relatively small portion of the more
than 40 stocks and assessment areas composing the DPS and do not confer
significant risk to the DPS throughout all or a significant portion of
its range.
Summary of Petitions Received
On January 22, 2004, NMFS received a petition from the Northwest
Ecosystem Alliance, the Center for Biological Diversity, Ocean
Advocates, People for Puget Sound, Public Employees for Environmental
Responsibility, Sam Wright, and the Friends of the San Juans to find
that the Cherry Point (Washington) stock of Pacific herring qualifies
as a DPS and warrants listing as a threatened or endangered species
under the ESA. Subsequently, on May 14, 2004, the same petitioners
submitted additional information including new genetic information on
the stock structure of Pacific herring in Puget Sound and the Strait of
Georgia (Washington) that had become available since the initial
petition was received on January 22, 2004. We considered the
petitioners' supplemental submission (in conjunction with the January
22, 2004, submission) as a distinct petition received by the agency on
May 14, 2004. On August 10, 2004, we issued our finding that the
petition received on January 22, 2004, fails to present substantial
scientific and commercial information indicating that the petitioned
action may be warranted, but that the petition received on May 14,
2004, does present substantial scientific and commercial information
indicating that the petitioned action may be warranted (69 FR 48455).
For a summary of the specific information presented in the two
petitions, the reader is referred to the above mentioned Federal
Register notice describing the petition findings. Most significantly,
the petition received on May 14, 2004, presented new genetic
information (Small et al., 2004) indicating that the Cherry Point
herring stock may be ``discrete'' and ``significant'' with respect to
the species, and may thereby qualify as a DPS for listing consideration
under the ESA. The majority of the information provided by the
petitioners regarding the viability of the Cherry Point herring stock
was evaluated in our earlier 2001 status review. The Cherry Point
herring stock has declined dramatically over the last three decades,
with the spawning biomass in 2000 representing a 94 percent decline
from historical observations. The 2001 status review noted that there
was a 50 percent chance that the Cherry Point stock would decline to 1
ton or less in 100 years (Stout et al., 2001). The petitioners also
provided additional biomass information from 2001-2004 for the period
since the 2001 status review.
Updated Status Review of Pacific Herring
The ESA requires that, as a consequence of accepting the above
petition, NMFS promptly commence a review of the species' status and
make a finding within 12 months after receiving the petition, whether
the petitioned action is warranted (ESA Section 4(b)(3)). To ensure
that our review was based on the best available and most recent
scientific information, we solicited information during a 60-day public
comment period regarding the DPS structure and extinction risk of, and
efforts being made to protect, the species (69 FR 48455; August 10,
2004).
We convened a Biological Review Team (BRT) (an expert panel of
scientists from NMFS' Northwest and Alaska Fisheries Science Centers,
and NOAA's National Ocean Service) to review the available information
and determine: (1) the DPS structure of Pacific herring, specifically
whether the Cherry Point herring stock qualifies as a ``species'' for
consideration under the ESA; and (2) whether the identified DPS(s) are
in danger of extinction or likely to become so in the foreseeable
future throughout all or a significant portion of its range. The BRT's
findings are presented in a January 24, 2005, memorandum ``Summary of
Scientific Conclusions of the Status of Cherry Point Pacific Herring
(Clupea pallasii) and Update of the Status of the Georgia
[[Page 33119]]
Basin Pacific Herring DPS,'' and are summarized briefly below.
Determination of ``Species''
Under the joint DPS policy (51 FR 4722; February 7, 1996) a
population segment may be considered discrete if it satisfies either
one of the following conditions: (1) it is markedly separated from
other populations of the same biological taxon as a consequence of
physical, physiological, ecological, or behavioral factors
(quantitative measures of genetic or morphological discontinuity may
provide evidence of this separation); or (2) it is delimited by
international governmental boundaries across which there is a
significant difference in exploitation control, habitat management or
conservation status. Under the joint DPS policy, if a population is
determined to be discrete, the agency must then consider whether it is
significant to the taxon to which it belongs. Considerations in
evaluating the significance of a discrete population include: (1)
persistence of the discrete population in an unusual or unique
ecological setting for the taxon; (2) evidence that the loss of the
discrete population segment would cause a significant gap in the
taxon's range; (3) evidence that the discrete population segment
represents the only surviving natural occurrence of a taxon that may be
more abundant elsewhere outside its historical geographic range; or (4)
evidence that the discrete population has marked genetic differences
from other populations of the species.
The BRT considered several types of information in evaluating the
DPS structure of Pacific herring, including whether the Cherry Point
herring stock qualifies for listing consideration as an independent
DPS. Information considered in evaluating the discreteness of stocks
include: (1) geographic variability in life-history characteristics and
morphology; (2) tagging and recapture studies indicating the level of
migration among stocks; and (3) genetic differentiation among stocks
reflective of marked reproductive isolation.
Relationship of Stock and DPS Concepts
Pacific herring in the vicinity of Cherry Point (Washington) are
considered to be a stock for management purposes in the state of
Washington (Bargmann, 1998). There is no definition of the term
``stock'' that is generally accepted by fisheries biologists (Stout et
al., 2001). The term stock has been used to refer to: (1) fish spawning
in a particular place or time, separated to a substantial degree from
fish spawning in a different place or time (Ricker, 1972); (2) a
population sharing a common environment that is sufficiently discrete
to warrant consideration as a self-perpetuating system that can be
managed separately (Larkin, 1972); (3) a species group or population of
fish that maintains and sustains itself over time in a definable area
(Booke, 1981); and (4) an intraspecific group of randomly mating
individuals with temporal or spatial integrity (Ihssen et al., 1981).
None of these definitions imply that a fish stock is ecologically,
biologically, or physiologically significant in relation to the
biological species as a whole. Hence, information establishing a group
of fish as a stock, such as the Cherry Point stock of Pacific herring,
does not necessarily qualify it as a DPS. A DPS may be composed of a
group of related stocks, or in some cases (if the evidence warrants) a
single stock, that form(s) a discrete population and are (is)
significant to the biological species as a whole.
Pacific Herring as a Metapopulation
A ``metapopulation'' is an aggregation of subpopulations linked by
migration, and subject to periodic extinction and recolonization events
(Levins, 1968, 1970). Observations of herring population structure in
the Atlantic and Pacific are consistent with this metapopulation
concept (McQuinn, 1997; Ware et al., 2000; Ware and Schweigert, 2001
,2002; Ware and Tovey, 2004): (1) local herring stocks are distributed
across spatially fragmented spawning habitat; (2) local stocks exhibit
partially independent demographics and dynamics; (3) there is
appreciable straying and gene flow among local populations; and (4)
there is evidence of disappearance and recolonization events.
Consistent with the consideration of Pacific herring as a
metapopulation, local spawning stocks of herring may demonstrate
distinctive demographic patterns and reproductive isolation over
relatively short temporal scales, yet over longer time periods
regularly exchange low levels of individuals or experience periodic
waves of dispersal during years of abundant recruitment.
DPS Determination for the Cherry Point Stock of Pacific Herring
The BRT concluded that the Cherry Point stock of Pacific herring
was ``discrete'' under the DPS policy (NMFS, 2005). The BRT determined
that the Cherry Point stock is markedly separated from other Pacific
herring populations as a consequence of physical, physiological,
ecological, or behavioral factors due to: (1) its locally unique late
spawn timing; (2) the locally unusual location of its spawning habitat
on an exposed section of coastline; (3) its consistently large size-at-
age and continued growth after maturation relative to other local
herring stocks; and (4) its differential accumulation of toxic
compounds relative to other local herring stocks, indicative of
different rearing or migratory conditions for Cherry Point herring.
Although the BRT determined that the Cherry Point stock represents
a discrete population, the BRT concluded that the stock is not
``significant'' to the taxon, and hence does not constitute a DPS
(NMFS, 2005). The BRT noted that: (1) over the broad geographic range
of Pacific herring, the local distinctiveness of the Cherry Point stock
is not unusual; (2) the late spawn timing of the Cherry Point stock is
not exceptional for Pacific herring, as there are other Pacific herring
stocks with similarly exceptionally late (as well as early) spawn
timing for their local region; (3) other Pacific herring stocks have
spawning habitats located on exposed coastlines subject to high-energy
wave action; and (4), given the level of genetic variability observed
within and between herring stocks, the level of genetic differentiation
exhibited by the Cherry Point stock was unlikely to indicate a marked
or evolutionarily significant level of differentiation. Based on this
information, the BRT concluded that the Cherry Point stock does not
satisfy the applicable DPS criteria for significance: Cherry Point does
not represent a unique or unusual ecological setting for Pacific
herring; the loss of the Cherry Point herring stock would not result in
a significant gap in the extensive range of Pacific herring; and the
Cherry Point stock does not exhibit marked genetic differentiation
relative to other Pacific herring populations.
Petition Finding
As summarized above, the May 14, 2004, petition submitted by the
Northwest Ecosystem Alliance and co-petitioners sought a finding that
the Cherry Point (Washington) stock of Pacific herring qualifies as a
DPS and warrants listing as a threatened or endangered species under
the ESA. In a Federal Register notice published on August 10, 2004 (69
FR 48455), we published the finding that the petition presented
substantial scientific and commercial information indicating that the
petitioned action may be warranted. As described in the preceding
section, we have determined that the Cherry Point stock of Pacific
herring is ``discrete,'' but is not ``significant'' under the joint
NMFS/U.S. Fish and Wildlife Service DPS policy. Thus, the
[[Page 33120]]
Cherry Point herring stock does not qualify as a DPS for listing
consideration under the ESA. Accordingly, we find that the action
sought by the May 14, 2004, Northwest Ecosystem Alliance et al.
petition is not warranted.
DPS Determination for Pacific Herring in the Georgia Basin
The BRT considered a number of alternative DPS configurations for
Pacific herring incorporating the Cherry Point herring stock, ranging
from the previously identified Georgia Basin DPS to a DPS encompassing
Pacific herring from San Diego (California) to Sitka (Alaska). Evidence
suggesting a DPS configuration larger than the Georgia Basin includes:
(1) tagging studies indicating that straying among herring stocks
occurs at spatial scales exceeding that of the Georgia Basin; (2)
information indicating relative genetic homogeneity of Pacific herring
stocks in the Pacific Northwest, Strait of Georgia, and British
Columbia; and (3) evidence supporting the concept that local herring
stocks are part of a larger Pacific herring metapopulation.
Notwithstanding this information, the majority of the BRT favored the
previous delineation of a Georgia Basin DPS of Pacific herring, finding
that the available information is insufficient to warrant modification
of the previous DPS delineation (NMFS, 2005). A variety of evidence
supports the finding that Georgia Basin Pacific herring satisfy the
criteria for discreteness and significance under the joint DPS policy,
including: the similarity in age composition of herring stocks in the
Strait of Georgia and Puget Sound supporting the discreteness of
Georgia Basin Pacific herring, and the ecological uniqueness of the
inshore waters of Puget Sound and the Strait of Georgia supporting the
significance of the Pacific herring in the Georgia Basin to the taxon
as-a-whole. (For a more detailed discussion of the information
supporting the delineation of the Georgia Basin DPS of Pacific herring,
the reader is referred to the Stout et al., 2001, status review). The
BRT delineated the Georgia Basin DPS as encompassing spawning stocks of
Pacific herring in the marine waters of Puget Sound, the Strait of
Georgia, and eastern Strait of Juan de Fuca in the United States and
Canada.
Review of the Species' Status
The ESA defines an endangered species as any species in danger of
extinction throughout all or a significant portion of its range, and a
threatened species as any species likely to become an endangered
species within the foreseeable future throughout all or a significant
portion of its range. Section 4(b)(1) of the ESA requires that the
listing determination be based solely on the best scientific and
commercial data available, after conducting a review of the status of
the species and taking into account those efforts, if any, being made
to protect such species.
The BRT considered the best available biological information to
assess the level of extinction risk for the Georgia Basin DPS of
Pacific herring. The BRT evaluated the DPS's extinction risk based on
risks to its abundance, productivity, spatial structure (including
spatial distribution and connectivity), and diversity. These four
``Viable Salmonid Population'' (VSP; McElhany et al., 2000) criteria
were developed to provide a consistent and logical framework for
assessing risks to populations and DPSs of West Coast salmon and
steelhead. Although initially developed for application to salmonid
metapopulations, the VSP criteria are well founded in the conservation
biology literature. Threats to a species' long-term persistence are
manifested demographically as risks to its abundance, productivity,
spatial structure, and productivity. These demographic risks thus
provide the most direct and robust biological indicators of extinction
risk. The BRT's assessment of extinction risk did not include an
evaluation of the likely or potential contribution of efforts being
made to protect the species, but was based solely on the available
biological information assuming that present conditions will continue,
and recognizing that natural demographic and environmental variability
is an inherent feature of present conditions. Below we summarize the
BRT's assessment of demographic risks to the Georgia Basin DPS's
abundance, productivity, spatial structure, and diversity, as well as
the BRT's extinction risk assessment for the DPS based on these risks.
Evaluation of Demographic Risks to the DPS
The majority opinion of the BRT was that there is very low risk to
the abundance of the Georgia Basin DPS, concluding that it is unlikely
that the current trends and levels of abundance contribute
significantly to the risk of extinction for the DPS, either by
themselves or in combination with other factors. The BRT noted that the
overall abundance of the DPS is at historically high levels since
monitoring began in the 1930s, in terms of the estimated biomass (the
recent abundance is well over 100,000 metric tons) and numbers of
herring (estimated at more than half a billion mature herring).
However, the BRT was concerned about the observed decline in the number
of the Cherry Point herring spawners from an estimated 24 million fish
in 2003 to 14 million fish in 2004.
The majority opinion of the BRT was that there is low risk to the
productivity of the DPS, concluding that it is unlikely to contribute
significantly to the risk of extinction for the DPS by itself, but that
there may be concern in combination with other factors. The BRT noted
that the DPS as a whole is highly productive with the overall
population trend and growth rate being highly positive. The BRT
observed that the overall DPS appeared to be in steep decline in the
1960s. However, some stocks have exhibited high levels of productivity
conferring resiliency to the DPS and reflecting an apparent ability to
rebound from past declines. The recent short-term trend for the overall
DPS is also very positive and recruitment levels remain high, despite
an apparent increase in adult mortality, possibly due to predation by
seals, disease factors, and other risk factors.
The BRT's appraisal of risk to the spatial structure of the DPS
ranged from very low risk to increasing risk. The majority opinion of
the BRT was that the DPS faces low risk to its spatial structure,
concluding that it is unlikely that spatial distribution and
connectivity contribute significantly to the risk of extinction by
themselves, and that there is some concern that they may in combination
with other factors. The BRT noted that the DPS remains well
distributed, with no gaps in the geographic range of spawning within
the DPS. All, or nearly all, of the historically occupied areas
continue to support spawning, and moderate migration rates based on
tagging information indicate little loss of connectivity among stocks
within the DPS. The BRT noted that increasing trends in the DPS are not
uniformly distributed among stocks or spawning areas, with the Central
and Northeastern portions of the DPS exhibiting declines. The BRT was
concerned that the bulk of the spawning distribution and abundance and
productivity in the DPS has become spatially compacted, particularly in
the northern half of the DPS. However, the BRT felt that declining
trends in some parts of the DPS are not a major concern in the context
of a herring metapopulation, particularly in light of observations of
high connectivity among stocks, and evidence of disappearance and
subsequent recolonization events in the
[[Page 33121]]
British Columbia portion of the DPS. The BRT also felt that the spatial
compaction of the most abundant and productive spawning stocks may be a
natural phenomenon.
The majority opinion of the BRT was that there is low risk to the
diversity of the DPS, concluding that it is unlikely that diversity
contributes significantly to the risk of extinction for the DPS, but
that it may in combination with other factors. The BRT noted that the
DPS continues to exhibit diversity in spawn timing and migratory
behavior both within and among spawning stocks. Although there is
limited long-term data regarding the genetic diversity of the DPS, the
BRT concluded that there has been no apparent genetic loss as compared
to other marine species. The BRT noted concern that the life-history
diversity of the DPS has apparently declined with the compression of
population age structure (a much smaller proportion of older age
classes), the decline of late-spawning herring (principally the Cherry
Point herring stock), and an apparent decline in nonmigratory inlet
herring stocks on the eastern side of the Strait of Georgia. The BRT
was uncertain whether the migratory/nonmigratory life-history types are
specific to certain populations, or are present to some degree in most
or all spawning stocks in the Strait of Georgia and Puget Sound.
Assessment of the Risk of Extinction
Informed by its assessment of demographic risks to the DPS, and a
consideration of the interactions among demographic risks, the BRT
concluded that the Georgia Basin DPS of Pacific herring is not at risk
of extinction in all or a significant portion of its range, nor likely
to become so in the foreseeable future. The BRT noted that the overall
abundance of the DPS is at historically high levels, and that the
linear extent of coastline used for spawning has been increasing. The
BRT concluded that the available information suggests that spawning
stocks in the Georgia Basin DPS operate as a ``mixed structure''
metapopulation (Harrison and Taylor, 1997) in which all subpopulations
are connected by migration, but some are relatively discrete with
weaker demographic linkages to other subpopulations in the DPS. It is
expected in a viable metapopulation that some local subpopulations will
be in decline, other subpopulations will be increasing, and some
suitable habitat patches may be unoccupied. Accordingly, the
observation that some local stocks are declining (principally the
Cherry Point stock, and the nonmigratory inlet stocks in the eastern
Strait of Georgia) is not by itself cause for concern about the long-
term viability of the DPS. Additionally, given the metapopulation
structure of the DPS, the BRT did not feel that the low demographic
risks (described in the previous section) collectively represent a risk
to the long-term viability of the DPS. The few declining stocks
represent a small proportion of the more than 40 stocks and assessment
areas that compose the Georgia Basin DPS. Evidence of significant
migration among stocks, high levels of gene flow, and disappearance and
subsequent recolonization events for Georgia Basin Pacific herring
suggest that local extirpations or stock declines confer little risk to
the overall DPS. The specific stocks exhibiting decline, however,
appear to exhibit greater demographic independence on generational time
scales relative to other stocks within the DPS. It is possible, given
their weaker connectivity with other spawning stocks in the DPS, that
if these declining stocks were lost, recolonization might take longer
than it might for a classical metapopulation in which subpopulations
are connected by higher rates of exchange. Nonetheless, the BRT did not
feel that the current risks to these declining stocks posed risks to
the DPS as a whole, or to any significant portion of the DPS.
The BRT considered whether recent factors have disrupted the
function of the metapopulation such that its long-term viability is
compromised. The BRT concluded that the patterns of abundance and
distribution within the Georgia Basin DPS appear to be typical of what
is seen in other herring metapopulations throughout northwestern North
America, including metapopulations in relatively pristine areas in
southeastern Alaska and British Columbia. The BRT noted, however, that
if habitat areas were lost or permanently degraded to the point that
they lacked the potential to support a spawning subpopulation, this
could seriously impair the function of the entire metapopulation. The
BRT concluded that the declining Cherry Point and eastern Strait of
Georgia inlet stocks do not appear to be limited by habitat factors.
The BRT concluded that the available evidence does not suggest unusual
levels of risk to the DPS as a whole, nor to any significant portion of
the DPS.
Consideration of ``Significant Portion of its Range''
The ESA defines endangered and threatened species in terms of the
level of extinction risk ``throughout all or a significant portion of
its range'' (sections 3(6) and 3(20)). If it is determined that the
defined species is not in danger of extinction or likely to become so
throughout all of its range, but there are major geographic areas where
the species is no longer viable, the statute directs that we must
address whether such areas represent a significant portion of the
species' range. As mentioned above, the BRT expressed concern regarding
declines in the Cherry Point stock and the non-migratory inlet stocks
in the eastern Strait of Georgia, but concluded that these stocks do
not represent a significant portion of the Georgia Basin DPS's range.
The BRT recognized that the Cherry Point stock is characterized by late
spawn timing, but noted that this timing represents the tail of the
distribution of run timing for the DPS as a whole and overlaps with the
range of spawn timing exhibited by other stocks in the DPS. The BRT
noted that the Cherry Point stock represents only one of about 40
recognized herring stocks and management areas within the DPS. Although
at peak abundance (in the early 1970s) the Cherry Point stock possibly
represented about 11 percent of the DPS's total biomass, other
historically large stocks were severely depressed at the time due to
over-harvesting and poor recruitment conditions. Thus, it is
speculative to conclude that the Cherry Point stock historically
represented a substantial portion of the ESU's biomass. With respect to
the declining inlet stocks in the eastern Strait of Georgia, the BRT
concluded that it is unclear whether their nonmigratory life history
represents a biologically significant portion of the DPS. Pentilla
(1986) suggested that some proportion of adult herring in Puget Sound
are nonmigratory as well. The BRT observed that it is unclear whether
the nonmigratory life-history type is specific to certain stocks or is
present to some degree in all herring stocks. Based on the above
information, the BRT concluded that the declining Cherry Point and
eastern Strait of Georgia inlet herring stocks individually and
collectively do not represent a significant portion of the Georgia
Basin DPS's range.
Efforts Being Made to Protect the Species
Section 4(b)(1)(A) of the ESA requires the Secretary to make
listing determinations solely on the basis of the best scientific and
commercial data available after taking into account efforts being made
to protect a species (emphasis added). Therefore, in making listing
determinations we first assess the
[[Page 33122]]
defined species' level of extinction risk, and identify factors that
have led to its decline. If it is determined that the species' survival
is at risk, we then assess existing efforts being made to protect the
species to determine if those measures ameliorate the risks faced by
the species. As described above, the BRT concluded that the defined
species' (the Georgia Basin DPS of Pacific herring) survival is not at
risk. It is not necessary to assess whether protective efforts reduce
risks to a DPS that has been determined to be viable.
Listing Determination
Informed by NMFS' findings that: (1) the spawning stocks of Pacific
herring in the Georgia Basin (including the marine waters of Puget
Sound, the Strait of Georgia, and eastern Juan de Fuca Strait in the
United States and Canada) constitute a DPS; and (2) the DPS is not in
danger of extinction or likely to become endangered in the foreseeable
future throughout all or a significant portion of its range, we
conclude that the Georgia Basin DPS of Pacific herring does not warrant
listing as threatened or endangered under the ESA.
References
Copies of the BRT's Status Review Update report, the petition, and
related materials are available on the Internet at http://www.nwr.noaa.gov, or upon request (see ADDRESSES section above).
Authority: 16 U.S.C. 1531 et seq.
Dated: June 1, 2005.
Rebecca Lent,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
[FR Doc. 05-11210 Filed 6-6-05; 8:45 am]
BILLING CODE 3510-22-S