[Federal Register Volume 60, Number 192 (Wednesday, October 4, 1995)]
[Rules and Regulations]
[Pages 51928-51932]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-24698]



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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 227

[I.D. 092895B]


Endangered and Threatened Species; West Coast Pink Salmon 
Petition Determination

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

ACTION: Notice of determination.

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SUMMARY: NMFS has determined that neither Elwha River nor lower 
Dungeness River pink salmon, as petitioned, constitute a ``species'' 
under the Endangered Species Act of 1973 (ESA). However, Elwha River 
and lower Dungeness River pink salmon are part of a larger 
evolutionarily significant unit (ESU) that includes all odd-year pink 
salmon stocks in Washington as far west as the Elwha River and in 
southern British Columbia, Canada (including the Fraser River and 
eastern Vancouver Island), as far north as Johnstone Strait. Further, 
NMFS has identified a second pink salmon ESU which includes even-year 
pink salmon residing in the Snohomish River, WA. NMFS has determined 
that, at the present time, neither of these ESUs warrant listing as a 
threatened or endangered species.

ADDRESSES: Environmental and Technical Services Division, NMFS, 525 NE 
Oregon Street, Suite 500, Portland, OR 97232.

FOR FURTHER INFORMATION CONTACT: Garth Griffin, Environmental and 
Technical Services Division, 503/231-2005 or Marta Nammack, Protected 
Species Management Division, 301/713-1401.

SUPPLEMENTARY INFORMATION:

Petition Background

    On March 14, 1994, the Secretary of Commerce received a petition 
from Professional Resources Organization-Salmon (PRO-Salmon), to list 
as threatened or endangered nine naturally spawning populations of 
salmon indigenous to northwestern Washington and to designate critical 
habitat under the ESA (PRO-Salmon, 1994). Two of the petitioned 
populations included pink salmon (Oncorhynchus gorbuscha) stocks 
residing in the Elwha River and the lower Dungeness River on 
Washington's Olympic Peninsula. NMFS published a document on September 
12, 1994 (59 FR 46808) that the petition presented substantial 
scientific information indicating that listings may be warranted. 
Concurrently, NMFS also announced its intention to initiate 
comprehensive status reviews of all species of Pacific salmon and 
anadromous trout in Washington, Oregon, Idaho, and California.
    In announcing these comprehensive status reviews, NMFS requested 
comments from any party having relevant information concerning (1) 
whether any salmon stock qualifies as a ``species'' under the ESA and 
(2) whether any salmon stock is endangered or threatened based on NMFS' 
listing criteria. In addition, NMFS specifically solicited information 
on the petitioned stocks. NMFS also requested information on areas that 
may qualify as critical habitat for all stocks of pink, chum, sockeye, 
and chinook salmon, and sea-run cutthroat trout in Washington, Oregon, 
Idaho, and California. Status reviews for west coast coho salmon and 
steelhead are nearing completion.

Biological Background

    The NMFS' Northwest Fisheries Science Center Biological Review Team 
(BRT) has reviewed the status of west coast pink salmon (Northwest 
Fisheries Science Center BRT, 1995), the prominent results of which are 
summarized below. A copy of the draft BRT report is available upon 
request (see ADDRESSES).
    Pink salmon occur in oceanic and freshwater areas around the 
Pacific rim of Asia and North America. Spawning populations range from 
Puget Sound, WA to Norton Sound, AK in North America and from North 
Korea to the Anadyr Gulf, Russia in Asia (Heard, 1991; Mathisen, 1994). 
In Washington, pink salmon regularly spawn as far south as southern 
Puget Sound and on the Olympic Peninsula along the Strait of Juan de 
Fuca (Williams et al., 1975, Washington Department of Fisheries (WDF) 
et al., 1993), with about 70 percent of the spawning in north Puget 
Sound (WDF et al., 1993).
    Across its natural range, pink salmon spawn in both large and small 
river systems in the late summer and fall. Spawning occurs in shallow 
pools and riffles exposed to moderately fast currents. Water 
temperatures during peak spawning activity range from about 5 deg.-
15 deg. C. Pink salmon mature at the smallest average size of any 
species of Pacific salmon (1.0-2.5 kg) and show marked sexual 
dimorphism (Davidson, 1935; Pritchard, 1937; Beacham and Murray, 1985). 
Spawning populations throughout much of the range of pink salmon may be 
extremely large, often exceeding hundreds of thousands of adults 
(Heard, 1991; WDF et al., 1993).
    Upon emerging from gravel, juvenile pink salmon migrate rapidly 
downstream, generally in schools. After a few weeks to a few months in 
estuaries and nearshore habitat, pink salmon migrate to sea where they 
reside for 12-16 months (Heard, 1991).
    In addition to their small size, extreme sexual dimorphism, and 
short freshwater residence as juveniles, pink salmon differ from other 
salmonids in that they lack a variable age structure. Almost all pink 
salmon are 2 years of age at maturity (Gilbert, 1914; Bilton and 
Ricker, 1965; Turner and Bilton, 1968). The most significant result of 
this rigid age structure has been the development of two separate, and 
often distinctive, broodlines of pink salmon. Fish in the broodline 
that mature in even-numbered years are referred to as ``even-year'' 
pink salmon while those that mature in alternate, odd-numbered 

[[Page 51929]]
years are referred to as ``odd-year'' pink salmon (Aspinwall, 1974; 
Johnson, 1979; McGregor, 1982; Beacham et al., 1985).
    The geographic distribution of the two pink salmon broodlines is 
not random. At the southern extent of the pink salmon range in North 
America, odd-year pink salmon are most abundant (Atkinson et al., 1967; 
WDF et al., 1993). Pink salmon populations in British Columbia are 
dominated by odd-year fish, whereas populations from the northern Queen 
Charlotte Islands and western Alaska are dominated by even-year fish 
(Neave, 1952; Aro and Shepard, 1967; Ricker and Manzer, 1974). In Asia 
and North America, even-year pink salmon generally become more abundant 
as latitude increases (Heard, 1991). The reasons for this variation in 
broodline dominance are not well understood (Ricker, 1962; Heard, 
1991).

Consideration as a ``Species'' Under the ESA

    To qualify for listing as a threatened or endangered species, Elwha 
River and lower Dungeness River pink salmon must constitute ``species'' 
under the ESA. The ESA defines a ``species'' to include any ``distinct 
population segment of any species of vertebrate * * * which interbreeds 
when mature.'' On November 20, 1991, NMFS published a policy (56 FR 
58612) describing how it will apply the ESA definition of ``species'' 
to Pacific salmonid species. This policy provides that a salmonid 
population will be considered distinct, and hence a species under the 
ESA, if it represents an ESU of the biological species. The population 
must satisfy two criteria to be considered an ESU: (1) It must be 
reproductively isolated from other conspecific population units, and 
(2) it must represent an important component in the evolutionary legacy 
of the biological species. The first criterion, reproductive isolation, 
need not be absolute, but must be strong enough to permit 
evolutionarily important differences to accrue in different population 
units. The second criterion would be met if the population contributed 
substantially to the ecological/genetic diversity of the species as a 
whole. Further guidance on the application of this policy is contained 
in ``Pacific salmon (Oncorhynchus spp.) and the Definition of Species 
under the ESA,'' which is available upon request (see ADDRESSES).

Reproductive Isolation

    For this criterion, NMFS has considered available information 
regarding geographic and life-history factors that may isolate pink 
salmon, as well as genetic factors which indicate reproductive 
isolation. The petitioners considered reproductive isolation with 
respect to eleven groups of pink salmon which have previously been 
identified in the State of Washington (WDF et al., 1993). In addition 
to those identified by the petitioner, previously identified pink 
salmon stocks include Snohomish River even-year pink salmon (the only 
even-year population in Washington, Oregon, Idaho, or California) and 
odd-year pink salmon populations in the following Washington rivers: 
(1) Nooksack, (2) Skagit, (3) Stillaguamish, (4) Snohomish, (5) 
Puyallup, (6) Nisqually, (7) Hamma Hamma, (8) Duckabush, (9) 
Dosewallips, and (10) upper Dungeness.
    With respect to the two criteria established by NMFS to define a 
``species'' of Pacific salmon, the petitioner contended that the lower 
Dungeness and Elwha River populations of pink salmon were both 
reproductively isolated from other pink salmon populations. 
Reproductive isolation was inferred primarily on the basis of distance 
to nearest neighboring population. For lower Dungeness River pink 
salmon, this distance is 10 km and for Elwha River pink salmon, this 
distance is 25 km. Genetic data, in the form of allozyme variation, 
support a hypothesis for at least partial reproductive isolation of the 
lower Dungeness River population (Shaklee et al., 1991), but no genetic 
data exist for the Elwha River population (WDF et al., 1993).
    Considerable evidence exists that indicates that even- and odd-year 
pink salmon are reproductively isolated. As discussed above under 
Biological Background, pink salmon exhibit a rigid age structure that 
results in two separate broodlines, even- and odd-year pink salmon. 
Throughout much of the range of this species, many rivers which support 
pink salmon populations produce both even- and odd-year broodlines 
which have no opportunity for interbreeding. As a result, this life 
history characteristic yields in each of these rivers two temporally 
isolated populations with almost no prospect of genetic exchange.
    Numerous genetic studies also support the belief that even- and 
odd-year pink salmon populations are reproductively isolated. Studies 
conducted by Okazaki (1984) and Reisenbichler (1992) found large 
genetic differences between even- and odd-year pink salmon from the 
same area, with the magnitude of the differences roughly comparable to 
that found between coastal and inland steelhead. Strong allozyme 
frequency differences between even- and odd-year broodlines spawning at 
the same locality have been reported in Alaska (Aspinwall, 1974; 
Johnson, 1979; McGregor, 1982), Canada (Beacham et al., 1985) and 
Russia (Salmenkova et al., 1981; Altukohov et al., 1983; Kartavstev, 
1991) for many polymorphic enzyme coding loci. In addition, Shaklee and 
Varnavskaya (1994) reported a large genetic difference between even- 
and odd-year Snohomish River pink salmon.

Ecological/Genetic Diversity

    For this criterion, NMFS considered environmental, ecological, and 
life history information in its assessment of potential pink salmon 
ESUs. Further, historic accounts of artificial propagation were 
considered to determine (1) How indigenous even- and odd-year west 
coast pink salmon populations have been altered, and (2) the 
relationship of historic populations to the presently defined ESUs.
    Little information was provided by the petitioner regarding NMFS' 
evolutionary significance criterion. The petitioner believed that 
spatial and temporal isolation of the lower Dungeness River population 
from the upper Dungeness River population, due to differences in run 
timing and spawning location, contribute to the distinctiveness of the 
lower river population. No quantitative data are available to support a 
hypothesis for the distinctiveness of the Elwha River population.

Environmental, Ecological, and Life-History Information

    Along the west coast of North America, climate varies primarily 
with latitude. As such, coastal regions exhibit north to south 
gradients of increasing average rainfall and decreasing average 
temperature. Streamflows in this region tend to be lowest in August and 
September, whereas water temperatures in northwestern Washington are 
generally highest in July and August (Hydrosphere Data Products, Inc., 
1993). Run timing and spawn timing are sensitive to these factors. As a 
result, streamflow patterns determine the temporal availability and 
suitability of spawning and incubation habitat for pink salmon.
    Pink salmon populations can vary considerably in run timing 
(Sheridan, 1962) and spawn timing within a single river system. This 
type of life-history variability can have consequences for a 
populations' fitness (Taylor, 1980; Mortensen et al., 1991) and 
therefore, is an important consideration when 

[[Page 51930]]
attempting to identify distinct population units (Gharett and Smoker, 
1993).
    In its analysis of run timing, NMFS found the time period of peak 
spawning for odd-year pink salmon populations to be highly variable 
among river systems in northwestern Washington. Pink salmon populations 
in the Strait of Juan de Fuca exhibit the earliest average date of peak 
spawning, while peak spawning of Nisqually River populations typically 
occurs an average of 1 month later. Timing of peak spawning of even-
year pink salmon in the Snohomish river is about 3 to 4 weeks earlier 
than that of odd-year fish, even though these two groups use much of 
the same habitat.
    In addition to differences in run timing, considerable variation in 
body size and shape is apparent among pink salmon populations. 
Available data indicate significant variation in the length of odd-year 
pink salmon among various drainages in Washington. In general, the 
smallest fish appear in cold, turbid rivers in Puget Sound (Nooksack 
and Nisqually Rivers), and along the Strait of Juan de Fuca (lower and 
upper Dungeness River), while the largest fish tend to exist in Hood 
Canal. Limited data regarding Snohomish River even-year pink salmon 
suggest that this population contains the smallest pink salmon observed 
in Washington.
    Comparisons of pink salmon length data among British Columbia and 
Washington indicate that, with the exception of Snohomish and Skagit 
River populations, odd-year pink salmon populations in Washington 
appear to be smaller than the average for odd-year British Columbia 
populations (Beacham and Murray 1985). However, this comparison is 
complicated by the fact that the Washington data were taken more 
recently than the British Columbia data. Even-year Snohomish River 
adult pink salmon are similar in size to pink salmon in even-year 
populations from the central mainland and northern Vancouver Island, 
but tend to be smaller than the even-year British Columbia average. 
Again, however, the data may not be strictly comparable, because they 
were taken in different years.
    Some evidence exists for recent declines in body length of odd-year 
pink salmon in Washington. This aspect raises concern regarding the 
ability of natural populations of pink salmon to recover, since, in 
general, decreases in body size equate to decreased fecundity and 
decreased juvenile production (but see Ricker et al., 1978; Ricker, 
1989). NMFS was unable to review any new data on body size in odd-year 
British Columbia pink salmon to determine whether size has declined in 
these stocks (Ricker et al., 1978; Ricker, 1989). However, the decline 
in body length of odd-year Washington pink salmon is qualitatively 
similar to a decline in length observed in pink salmon returning to 
Auke Creek, AK, over the last 20 years. Further, data estimated from 
catches of southeastern Alaska pink salmon suggest similarly declining 
body length trends over an even longer period (Marshall and Quinn, 
1988). Therefore, NMFS believes that this factor should be closely 
monitored to ensure that natural populations remain viable in the 
future.
    Homing and straying are prominent features of Pacific salmon 
biology that can have significant effects on population structure. 
Consequently, these issues are relevant to ESU determinations for these 
species. Pink salmon have a widespread reputation for straying at 
higher rates than other species of Pacific salmon (Horrall, 1981). If 
true, the result may be a less conspicuous population structure and, 
potentially, reduced opportunity for local adaptations to be 
maintained. Few technically sound studies have been conducted to 
estimate straying rates of Pacific salmon and provide empirical 
evidence supporting the hypothesis that pink salmon stray at relatively 
higher rates than other species of Oncorhynchus is mixed (Quinn, 1993; 
Altukhov and Salmenkova, 1994). However, the rapid colonization of 
systems newly available to pink salmon indicates that this species has 
an unusual ability to expand into suitable habitat when conditions are 
favorable (Merrell, 1962; Kwain and Laurie, 1981; Heard, 1991).
    It is difficult to say with any degree of certainty that pink 
salmon stray more frequently relative to other species of Pacific 
salmon. It is apparent that straying in pink salmon may be highly 
dependent on spawning location and on conditions at time of spawning. 
The consequences of straying on pink salmon populations are not clear, 
but such consequences may contribute to less conspicuous population 
structure and reduced local adaptations.

Artificial Propagation

    It is commonly believed that even-year pink salmon were 
historically either absent from Washington or were at an abundance too 
low to sustain harvest (Rounsefell, 1938; Ellis and Noble, 1959). 
Consequently, WDF made several attempts earlier in this century to 
establish even-year pink salmon runs in northwestern Washington (WDF, 
1916-1964; Neave, 1965; Roppel, 1982). More than 82 million pink salmon 
eggs were transported from Alaska to various locations in Washington in 
even-numbered years between 1910 and 1932. In addition, more than one 
million odd-year Alaskan pink salmon eggs were brought into Washington 
from southeastern Alaska in 1929. An estimated 85 million juveniles 
released between 1911 and 1933 produced no recorded returns of even-
year pink salmon adults to Washington rivers, including the Snohomish 
River (Ellis and Noble, 1959; Neave, 1965). Attempts to establish even-
year pink salmon in Washington were renewed between 1944 and 1956 with 
the transport of nearly 4 million eggs from the Skeena River drainage 
in British Columbia, Canada. Of the 1.3 million fry released, at least 
several hundred are believed to have returned as adults. However, no 
evidence exists that returns were sustained beyond one or two 
generations (Ellis and Noble, 1959; Neave, 1965).
    Even-year pink salmon in Washington are known only to occur in the 
Snohomish River (WDF et al., 1993). The origin of this population is 
uncertain; these fish may be endemic or may have resulted from one or 
more transplants of even-year fish from Alaska or Canada. Regardless of 
its origin, the Snohomish River even-year population has apparently 
been naturally self-sustaining for at least the last 18 generations 
(about 36 years).
    In addition to stock transplants, relatively large numbers of pink 
salmon were produced in Washington hatcheries around Puget Sound from 
the early 1950's through the late 1980's. Transfers of fish among 
hatcheries and drainages were common during this period; however, very 
few pink salmon were transplanted to areas outside Puget Sound. Three 
hatcheries have dominated pink salmon production in Washington: Hood 
Canal Hatchery on Finch Creek in Hood Canal, Puyallup Hatchery on 
Voight Creek in south Puget Sound, and Dungeness Hatchery on the 
Dungeness River.
    In recent years, only Hood Canal Hatchery has maintained an active 
pink salmon propagation program. Most hatchery production of pink 
salmon in Washington is composed of odd-year fish released from this 
facility. Originally, in 1953, broodstock for this hatchery was derived 
from adult pink salmon returning to the Dungeness and Dosewallips 
Rivers. Presently, this hatchery uses native broodstock, which are 
generally released into Finch Creek, the location of the hatchery. Over 
the past decade releases from Hood Canal hatchery have averaged about 1 
million fry released every other year into Finch 

[[Page 51931]]
Creek. Therefore, although artificial propagation of pink salmon in the 
past may have affected the population structure of odd-year pink salmon 
in Puget Sound, recent hatchery production has probably had little 
effect on this structure due in part to the use of native broodstocks.

ESU Determinations

    Based on its evaluation of genetic, life-history, and ecological 
information pertaining to pink salmon, NMFS has determined that two 
ESUs exist for North American pink salmon in WA and southern British 
Columbia, Canada. These two ESUs include: (1) even-year pink salmon 
residing in the Snohomish River, Washington (and likely, even-year pink 
salmon populations in southern British Columbia); and (2) odd-year pink 
salmon occurring in Washington as far west as the Elwha River and in 
southern British Columbia, Canada (including the Fraser River and 
eastern Vancouver Island) as far north as Johnstone Strait. A summary 
of the information that led to these conclusions is presented below.

Even-Year Pink Salmon ESU

    A single population of even-year pink salmon occurs in the United 
States south of Alaska--in the Snohomish River, WA. Genetically, this 
population is much more similar to even-year pink salmon from British 
Columbia and Alaska than it is to odd-year pink salmon from Washington. 
In addition, a similar pattern is found in phenotypic and life-history 
traits such as body size and run timing. This result is consistent with 
numerous studies that have found large genetic differences between 
even- and odd-year pink salmon from the same area (e.g., Aspinwall, 
1974; Beacham et al., 1985; Kartavtsev 1991).
    The Snohomish River even-year pink salmon population is 
geographically isolated by several hundred kilometers from other even-
year pink salmon populations of appreciable size. However, life-history 
features of the Snohomish River even-year population are similar to 
those in other even-year populations from central British Columbia. For 
example, time of peak spawning of even-year pink salmon in the 
Snohomish River is comparable to that of even-year British Columbia 
pink salmon and 3-4 weeks earlier than that of odd-year pink salmon in 
the Snohomish River. Genetic analyses are highly dependent upon 
standardization between laboratories, but available data indicate that 
even-year Snohomish River pink salmon are among the most distinctive of 
any pink salmon sample from the United States or southern British 
Columbia.
    At the present time, the Snohomish River even-year pink salmon 
population is relatively small, on the order of a few thousand adults 
per generation. In defining the term ``species'' as it applies to 
Pacific salmon, NMFS has previously stated that a population should not 
be considered an ESU if the historic size (or historic carrying 
capacity) is too small for it to be plausible to assume the population 
has remained isolated over an evolutionary important time period 
(Waples, 1991). The fact that small spawning populations are regularly 
observed may reflect the dynamic processes of extinction, straying, and 
recolonization (Waples, 1991). Therefore, the small size of the current 
Snohomish River even-year pink salmon population suggests that it may 
be part of a larger geographic unit on evolutionary time scales 
(hundreds or thousands of years). The odd-year Snohomish River pink 
salmon population, which has the same spawning habitat available, is 1-
2 orders of magnitude larger; therefore, it is possible that the even-
year population was once much larger in the past. If that were the 
case, long-term persistence of this population in isolation would be 
easier to explain, since larger, isolated populations are likely to be 
more resilient to extinction than a small population such as this one.

Odd-Year Pink Salmon ESU

    Genetic information indicates that odd-year pink salmon from 
southern British Columbia and Washington are clearly in a different 
evolutionary lineage than nearby even-year populations and more 
northerly odd-year populations. Within the southern British Columbia-
Washington pink salmon group, there is also evidence of geographic 
population genetic structure, with detectable differences among groups 
of populations from the Dungeness River, Hood Canal, Puget Sound, and 
Fraser River, and southern and central British Columbia, Canada. In 
some analyses, Nisqually and Nooksack River populations in Puget Sound, 
WA are genetic outliers not similar to each other. Even so, none of the 
genetic differences within the southern British Columbia-Washington 
pink salmon group is very large in absolute magnitude.
    Based on currently available information, NMFS concludes that the 
northern boundary of the odd-year ESU corresponds to the Johnstone 
Strait region of British Columbia, Canada. The ESU does not include 
northern British Columbia, Alaskan, or Asian populations of pink 
salmon. In Washington, westernmost populations in this ESU are found in 
the Dungeness River, but the ESU presumably would also include the 
Elwha River population, if a remnant still exists (see Status of West 
Coast Pink Salmon ESUs). Some uncertainty exists whether populations in 
the Dungeness River (and possibly the Elwha River in Washington and 
southern Vancouver Island in British Columbia) belong in a separate 
ESU. Further, given the uncertainty associated with the presence of 
populations outside this range, NMFS believes that insufficient 
information presently exists to determine whether other populations of 
pink salmon on the Olympic Peninsula or locations further south should 
be included in this ESU.

Status of West Coast Pink Salmon ESUs

    In considering whether these ESUs are threatened or endangered 
according to the ESA, NMFS evaluated both qualitative and quantitative 
information. Qualitative evaluations considered recent, published 
assessments by agencies or conservation groups of the status of pink 
salmon within the geographic area. Quantitative assessments were based 
on current and historical abundance information and time series data 
compiled from a variety of Federal, state, and tribal agency records.
    Nehlsen et al. (1991) considered salmon stocks throughout 
Washington, Idaho, Oregon, and California and enumerated all stocks 
that they found to be extinct or at risk of extinction. Pink salmon 
stocks in the Klamath and Sacramento Rivers, located in California, 
were considered extinct. Three stocks were considered to be at high 
risk of extinction (Russian River, CA; Elwha River, WA; and Skokomish 
River, WA) and one at moderate risk of extinction (Dungeness River, 
WA). Pink salmon stocks that do not appear in their summary were either 
not considered to be at risk of extinction or there was insufficient 
information to classify them.
    The WDF et al. (1993) categorized all salmon stocks in Washington 
on the basis of stock origin, production type, and status (healthy, 
depressed, critical, or unknown). Of the 15 pink salmon stocks 
identified by WDF et al. (1993), nine were classified as healthy, two 
as critical (lower Dungeness and Elwha Rivers), two as depressed (upper 
Dungeness and Dosewallips Rivers), and two as unknown (North and Middle 
Fork Nooksack, and South Fork Nooksack River). All runs were classified 
as wild production and all, 

[[Page 51932]]
except those in the North and Middle Forks of the Nooksack River, were 
reported to be of native origin. In the planned 1995 revision of the 
Washington State Salmon and Steelhead Inventory, the WDF intends to 
recommend that Elwha River pink salmon be classified as extinct since 
no adult fish have been observed since 1989 despite extensive annual 
surveys (Northwest Fisheries Science Center BRT, 1995).
    Based on available data, it is difficult to ascertain with any 
degree of certainty the extent of the ESU that contains the Snohomish 
River even-year pink salmon population. The small size of the current 
Snohomish River even-year population suggests that it may be part of a 
larger geographic unit over evolutionary time. The Snohomish River 
even-year population is geographically isolated by several hundred 
kilometers from other even-year populations of appreciable size; 
however, similar life history characteristics, such as time of peak 
spawning, are similar to that of even-year British Columbia pink 
salmon. Results of genetic data are heavily dependent on whether an 
adjustment is made for possible differences in methods for recording 
data. Further, it is not clear which analyses should be preferred, 
those with or without adjustment for possible bias.
    Given the uncertainty associated with the extent of the even-year 
ESU, NMFS considered the status of this ESU under two scenarios: (1) 
The ESU is composed solely of the Snohomish River pink salmon 
population, and (2) the ESU contains populations of even-year pink 
salmon from British Columbia in addition to the Snohomish River 
population. Under both scenarios, NMFS was unable to demonstrate that 
this ESU is currently at risk of extinction or endangerment. Available 
information indicates that the Snohomish River pink salmon population 
is relatively small with, generally, an increasing trend in abundance 
in recent years. Further, even-year pink salmon populations in British 
Columbia are generally stable or increasing. Therefore, under both ESU 
scenarios, NMFS has concluded that even-year pink salmon do not 
presently warrant listing under the ESA.
    Similar to the even-year ESU, uncertainty remains regarding the 
extent of the odd-year pink salmon ESU. Environmental and ecological 
characteristics generally show a strong north-south trend; however, 
NMFS was unable to identify any substantial differences that 
consistently differentiate Washington and British Columbia odd-year 
pink salmon populations. Although odd-year pink salmon show 
considerable variation in body size among populations in Washington, 
the range of variation does not exceed that found in British Columbia. 
Genetic information shows a clear distinction between nearby even-year 
pink salmon and more northerly odd-year populations. Within the 
southern British Columbia and Washington pink salmon group, evidence of 
geographic population structure exists; however, none of the genetic 
differences is very large in absolute magnitude. Even though genetic 
differences among odd-year pink salmon are relatively small, the 
consistent genetic differences among geographically isolated groups of 
populations suggest that there has been some degree of reproductive 
isolation among pink salmon populations in this region.
    Most populations in the odd-year pink salmon ESU appear to be 
healthy, and overall abundance appears to be close to historic levels. 
The two most distinctive Puget Sound populations, the Nooksack and 
Nisqually River populations, both show non-significant trends in recent 
abundance. No other factors were identified by NMFS which would 
threaten the near-term survival of these populations. However, the two 
populations on the northern Olympic Peninsula (both of which occur in 
the Dungeness River and one of which, in the lower river, was 
petitioned for listing) appear to be at the greatest risk of extinction 
in this ESU. Nevertheless, because (1) most of the populations in this 
ESU are stable or increasing and (2) the two populations at greatest 
risk are not consistently differentiated from other populations in the 
ESU with regard to genetic or life history characters, NMFS concludes 
that the odd-year pink salmon ESU is not presently at risk of 
extinction or endangerment. Furthermore, NMFS concludes that the 
geographic boundaries of the even- and odd-year pink salmon ESUs should 
be regarded as provisional. As such, these geographic boundaries are 
subject to revision should substantial new information become 
available. The NMFS welcomes the submission of any new information that 
may help resolve uncertainties regarding the extent of these pink 
salmon ESUs.

Determination

    After a thorough analysis of all available information, NMFS has 
determined that neither Elwha River nor lower Dungeness River pink 
salmon, as petitioned, constitute a ``species'' under the ESA. However, 
Elwha River and lower Dungeness River pink salmon are part of a larger 
ESU that includes all odd-year pink salmon stocks in Washington as far 
west as the Elwha River and in southern British Columbia, Canada 
(including the Fraser River and eastern Vancouver Island), as far north 
as Johnstone Strait. Further, NMFS has identified a second ESU for pink 
salmon which includes even-year pink salmon residing in the Snohomish 
River, WA. NMFS has determined that, at the present time, neither ESU 
warrants listing as a threatened or endangered species.

References

    A list of references is available upon request (See ADDRESSES).

    Dated: September 28, 1995.
Rolland A. Schmitten,
Assistant Administrator for Fisheries, National Marine Fisheries 
Service.
[FR Doc. 95-24698 Filed 9-29-95; 4:08 pm]
BILLING CODE 3510-22-F