Endangered and Threatened Species: 90-Day Finding on Petition to Redefine the Southern Extent of the Central California Coho Salmon Evolutionarily Significant Unit, 14683-14687 [E6-4192]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 71, Number 56 (Thursday, March 23, 2006)]
[Notices]
[Pages 14683-14687]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-4192]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No. 060317074-6074-01; I.D. No. 031306A]


Endangered and Threatened Species: 90-Day Finding on Petition to 
Redefine the Southern Extent of the Central California Coho Salmon 
Evolutionarily Significant Unit

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

ACTION: Notification of 90-day petition finding.

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SUMMARY: We, the National Marine Fisheries Service (NMFS), have 
received a petition to redefine the southern boundary of the Central 
California Coast (CCC) coho salmon (Oncorhynchus kisutch) 
Evolutionarily Significant Unit (ESU) to exclude coho salmon 
populations in the counties (Santa Cruz County and coastal San Mateo 
County) south of San Francisco Bay, California. Coho salmon populations 
south of San Francisco Bay are part of the CCC coho salmon ESU, which 
is listed as an endangered species under the Endangered Species Act of 
1973, as amended (ESA). The petition fails to present substantial 
scientific or commercial information indicating that the petitioned 
action may be warranted. Furthermore, after reviewing the best 
available scientific and other information, NMFS finds the petitioned 
action is not warranted.

DATES: The finding announced in this document is effective March 23, 
2006.

ADDRESSES: Comments or questions concerning this petition finding 
should be submitted to the Regional Administrator, Southwest Region, 
NMFS, 501 W. Ocean Blvd., Suite 5200, Long Beach, CA 90802-4213.

FOR FURTHER INFORMATION CONTACT: Craig Wingert, NMFS, Southwest Region, 
(562) 980-4021, or Marta Nammack, NMFS, Office of Protected Resources, 
(301)713-1401.

SUPPLEMENTARY INFORMATION:

Background

    Section 2(b) of the ESA outlines the purposes of the statute which 
are to provide a means whereby the ecosystems upon which endangered and 
threatened species depend may be conserved, to provide a program for 
the conservation of such endangered species and threatened species, and 
to take such steps as may be appropriate to achieve the purposes of the 
treaties and conventions set forth in subsection (2)(a).
    Section 4(a) of the ESA directs the Secretary to determine whether 
a species is endangered or threatened solely on the basis of the best 
scientific and commercial data available to him after conducting a 
review of the status of the species and after taking into account those 
efforts, if any, being made by any state or foreign nation, to protect 
such species.
    The ESA authorizes the listing, delisting, or reclassification of a 
species, subspecies, or distinct population segment of a vertebrate 
species (DPS) (16 U.S.C. 1533(4)(a)). We have determined that DPSs are 
represented by Evolutionarily Significant Units (ESUs) for Pacific 
salmon, and we treat ESUs as ``species'' under the ESA (Salmonid ESU 
Policy, 56 FR 58612; November 20, 1991). Under the Salmonid ESU policy, 
a stock of Pacific salmon is considered a distinct population, and 
hence a ``species'' under the ESA, if it represents an evolutionarily 
significant unit (ESU) of the biological species. A stock must satisfy 
two criteria to be considered an ESU: (1) It must be substantially 
reproductively isolated from other conspecific population units; and 
(2) It must represent an important component in the evolutionary legacy 
of the species.
    Coho salmon populations that occupy coastal streams in Santa Cruz 
and San Mateo counties south of San Francisco Bay are currently 
considered part of the larger CCC coho salmon ESU. This ESU was 
originally listed as a threatened

[[Page 14684]]

species on October 31, 1996 (61 FR 56138), but has recently been 
reclassified as an endangered species (70 FR 37160; June 28, 2005). 
While the ESA authorizes the listing, delisting, or reclassification of 
a species, subspecies, or DPS of a vertebrate species, it does not 
authorize the listing or delisting of a subset or portion of a listed 
species, subspecies, or DPS (16 U.S.C. 1533(4); 50 CFR 424.11(d)).
    Section 4(b)(3)(A) of the ESA requires that, to the maximum extent 
practicable, within 90 days after receiving a petition for delisting, 
the Secretary make a finding whether the petition presents substantial 
scientific information indicating that the petitioned action may be 
warranted. The ESA implementing regulations for NMFS define 
``substantial information'' as the amount of information that would 
lead a reasonable person to believe that the measure proposed in the 
petition may be warranted (50 CFR 424.14(b)(1)). In evaluating a 
petitioned action, the Secretary must consider whether such a petition: 
(1) clearly indicates the recommended administrative measure and the 
species involved; (2) contains a detailed narrative justification for 
the recommended measure, describing past and present numbers and 
distribution of the species involved and any threats faced by the 
species; (3) provides information regarding the status of the species 
over all or a significant portion of its range; and (4) is accompanied 
by appropriate supporting documentation (50 CFR 424.14(b)(2)).

The Petition

    On November 12, 2003, we received a petition from Mr. Homer T. 
McCrary (petitioner) to redefine the southern extent of the CCC coho 
salmon ESU boundary by excluding coho salmon populations occupying 
watersheds in Santa Cruz and coastal San Mateo counties, California, 
from the ESU. We received a petition addendum from the petitioner on 
February 9, 2004, that provided additional information clarifying the 
original petition and responding to new information regarding coho 
salmon museum specimens. On July 16, 2004, our Southwest Fisheries 
Science Center (Science Center) provided a scientific evaluation of the 
petition which was forwarded to the petitioner. On October 18 and 25, 
2004, respectively, the petitioner responded to the Science Center's 
evaluation with a critique and supplemental information. The Science 
Center provided a second scientific evaluation of the petition and of 
the October 2004 information on March 17, 2005, which was subsequently 
forwarded to the petitioner. The petitioner responded to the Science 
Center's second evaluation on May 10, 2005. On October 11, 2005, and 
December 5, 2005, the petitioner further questioned the Science 
Center's conclusions and the listing of these populations south of San 
Francisco pursuant to NMFS' Salmonid ESU policy (56 FR 58612; November 
20, 1991). NMFS' Southwest Region and Science Center staff met with the 
petitioner and his representatives on November 30, 2005, to discuss 
information contained in the petition and supplementary information 
provided by the petitioner, the Science Center's evaluations of the 
petition, and NMFS' Salmonid ESU policy.
    The petition and supplemental information and correspondence from 
the petitioner assert that coho salmon populations south of San 
Francisco Bay do not meet NMFS' criteria for protection as a threatened 
(or endangered) species, pursuant to the ESA. The petitioner's 
assertions are based on the following: (1) geographic range 
descriptions for coho salmon in the early scientific literature and old 
newspaper accounts that the petitioner asserts document San Francisco 
as the southern boundary for the species; (2) the absence of coho 
salmon remains in the refuse sites (i.e., middens) of the native 
people; (3) the physical characteristics (i.e., climate, geology, and 
hydrology) of streams originating in the Santa Cruz mountains, which 
are inhospitable to coho salmon; (4) the absence of self-sustaining, 
natural populations of coho salmon in streams south of San Francisco 
Bay prior to 1906 when exotic (out-of-ESU) stocks were artificially 
introduced, and the resulting conflict of NMFS' ESU policy for Pacific 
salmon with protecting these populations; and (5) the ephemeral, 
artificially maintained (i.e., through hatchery production) nature of 
the extant coho salmon in streams south of San Francisco that precludes 
them from constituting an important component in the evolutionary 
legacy of the species. Based on these arguments, the petitioner has 
requested that we redefine the southern boundary of the CCC coho salmon 
ESU to include only those populations north of San Francisco Bay.
    To inform our decision on whether the petition presents substantial 
information indicating that the petitioned action may be warranted, we 
requested the Southwest Fisheries Science Center Laboratory in Santa 
Cruz to review the petition and all supplemental information to assess 
its scientific credibility. In addition, we reviewed the information in 
the petition and supplemental documents to see if it provided any 
rationale for why including the southern populations in the CCC coho 
ESU did not comport with NMFS' Salmonid ESU Policy (56 FR 58612; 
November 20, 1991).

Early Scientific Accounts

    The petition asserts that there is no valid historic (including 
accounts from local newspapers) or scientific source which documents 
the presence of coho salmon south of San Francisco prior to 1912. 
Because the scientific documentation published prior to 1906, primarily 
by early ichthyologist David Starr Jordan (Jordan, 1892; Jordan and 
Gilbert, 1876-1919; Jordan, Gilbert, and Hubbs, 1882; Jordan and 
Everman, 1902; Jordan, 1904a; Jordan, 1904b; etc.), referenced coho 
salmon as occurring north of San Francisco, the petitioner concludes 
coho salmon were absent south of San Francisco. We disagree with the 
petitioner's claim. Jordan was describing the North American 
distribution of coho salmon in a general ichthyofaunal reference, and 
his use of commonly used phraseology that a species is abundant up to, 
or from, a geographical landmark does not mean that the species was 
absent in areas beyond the referenced landmark. Jordan also wrote, 
``This species (coho salmon) is not common south of the Columbia, but 
is sometimes taken in California'' (Jordan, 1894). Coho salmon were 
more abundant in Oregon and California than indicated by this 
statement, further highlighting the problematic nature of relying on 
general ichthyofaunal references for precise species distribution 
information. Regarding the various excerpts from early newspaper 
articles, we view these as non-scientific reports of already depressed 
salmonid populations rather than as definitive scientific proof that 
these fish were unquestionably absent from the area.
    We also disagree with the petitioner's claim that coho salmon are 
not native to streams south of the San Francisco Bay. In fact, coho 
salmon specimens collected from San Mateo and Santa Cruz county streams 
in 1895 and currently held in the California Academy of Science's (CAS) 
Ichthyological Collection (CAS, 2004) represent clear evidence that 
coho salmon were native to, and present in, streams south of San 
Francisco Bay prior to 1906. The CAS maintains four samples (jars) of 
specimens that authenticate the collection of 11 native coho salmon 
from Waddell Creek and four from Scott Creek in Santa Cruz County on 
June 5, 1895, by the party of Rutter, Scofield, Seale, and Pierson 
(CAS, 2004). Also, two coho salmon

[[Page 14685]]

specimens were collected from San Vicente Creek in Santa Cruz County 
and one from Gazos Creek in San Mateo County by the same party of 
investigators. Although the collection of these latter specimens is not 
dated, they can reasonably be assumed to have been collected during the 
same period. Coho salmon continue to persist in these four streams 
today.
    In correspondence the petitioner submitted to us following 
submission of the petition, the petitioner questioned the validity of 
these coho salmon specimens based on an assumption there were lapses in 
their chain of custody. The petitioner also suggested that, even if the 
coho salmon specimens were valid, they represent nothing more than 
evidence of ephemeral colonies of coho salmon in the streams south of 
San Francisco Bay. The petitioner's questions regarding the validity of 
these specimens focus on three points: (1) damage suffered to the 
ichthyological collection as a result of the 1906 San Francisco 
earthquake when it was housed at Stanford University in Palo Alto, 
California; (2) one of the four jars of specimens is missing; and (3) 
the original misidentification of the specimens as chum and Chinook 
salmon and their subsequent corrected identification as coho salmon by 
an unknown individual at an unknown date.
    In a letter to us dated October 25, 2004, the petitioner cited an 
excerpt from the Stanford Ichthyological Bulletin (Bohlke, 1953), 
describing damage to the University's fish collections. The excerpt 
from Bohlke (1953) states that ``(m)ore than 1,000 jars and bottles 
were broken although the majority survived intact;'' however, ``much 
[specimens from broken containers] was saved although there were 
numerous instances in which the material had to be discarded. 
Nonetheless, some doubt regarding some specimens and their origin 
inevitably occurred * * * and labels stating that the original 
containers were lost during the earthquake.'' (Bohlke, 1953). We 
believe it is improbable that all 1,895 specimens had their original 
containers broken, ended up on the floor, were misidentified from their 
original labels, and had their `earthquake' labels removed. According 
to the Senior Collections Manager for the CAS Ichthyological Collection 
(Spence, pers. comm., 2004), there is no evidence to suggest that the 
fish in the collection jars are not coho salmon, or that the specimens 
are not the same fish collected by Rutter, Scofield, Seale, and Pierson 
in 1895. In addition, the Collections Manager added that the appearance 
of the specimens is consistent with collection and preservation 
protocols used in the late 1800's (Spence, pers. comm., 2004). Prior to 
the early 1900s, specimens were preserved directly in alcohol, whereas 
in subsequent years, fish were initially ``fixed'' in a diluted 
formaldehyde solution (formalin) and then transferred to alcohol. The 
lens of the fish eye turns white in fish preserved directly in alcohol, 
but appears darker in those fixed in formalin. The Collections Manager 
stated that, although not a definitive test, ``the eyes of all the 
specimens in question are consistent with direct alcohol preservation 
(no formalin)'' (Spence, pers. comm., 2004).
    Regarding the one missing specimen jar, the Collections Manager 
indicated that it evidently was misplaced because the CAS was preparing 
to move to another location, but the jar has since been relocated 
(Spence, pers. comm., 2004) . With regard to the issue of 
misidentification, the Collections Manager confirmed that, when these 
specimens were originally entered into the Stanford University ledger, 
they were misidentified as chum and Chinook salmon rather than coho 
salmon (NMFS, 2005a, unpublished memorandum). However, the specimens 
were subsequently re-identified as coho salmon while still in the 
possession of Stanford University before the ichthyological collection 
was transferred to the CAS. When the CAS entered the Stanford 
University ichthyological collection into an electronic database in the 
1990s, it initially used the original Stanford University ledgers as 
the source for species identifications and incorrectly entered the 
species identifications (NMFS, 2005a, unpublished memorandum). The 
database entries were corrected in 1999 when the original collection 
jars were examined and the re-identifications were once again 
discovered. These specimens were recently re-examined by CAS museum 
curators Dr. McCosker and Dr. Iwamoto, who concluded all but one of the 
specimens are coho salmon (Spence, pers. comm., 2004). The fact that 
these specimens were misidentified when originally catalogued is not 
particularly surprising, given the era in which they were collected. 
Prior to 1900, the taxonomy and nomenclature of salmonids was far from 
settled and not much was known about the early life history of the five 
Pacific salmon species. Based on the available information and our 
investigation, we find no reason to doubt that these fish are in fact 
the coho salmon collected from streams in San Mateo and Santa Cruz 
counties in 1895. Tissues from the 1895 specimens were provided by the 
petitioner to the Santa Cruz Laboratory for genetic analysis; however, 
the laboratory was not able to obtain any useable material for genetic 
analysis (Adams, pers. comm., 2006).
    Finally, we disagree with the petitioner's claim that, even if 
verified, the coho salmon specimens are only evidence of an ephemeral 
colony resulting from favorable ocean conditions rather than evidence 
of a native population. Metapopulation dynamics characterized by local 
extinction and recolonization, and reinforcement by straying, is 
typical for coho salmon in California (NMFS, 2005a, unpublished 
memorandum). Accordingly, it would be natural for coho salmon 
populations at the southern end of the species range to be founded and 
continually reinforced by straying migrants from elsewhere in the 
species range. NMFS believes these coho salmon populations south of San 
Francisco are part of the CCC coho salmon ESU, which functions as a 
metapopulation, and their inclusion in this ESU is consistent with the 
agency's ESU Salmonid policy (56 FR 58612).

Archeological Excavations

    The petitioner argues that the failure of Gobalet et al. (2004) to 
identify the remains of coho salmon in the 1,238 fish bones found in 
Native American middens in Santa Cruz and coastal San Mateo counties is 
another line of evidence that the species is not native to the area. 
NMFS disagrees with the petitioner's claim. Gobalet et al. (2004) wrote 
``(t)he samples from the eight archaeological sites in San Mateo and 
Santa Cruz counties and the two sites previously reported by Gobalet 
and Jones (1995) were limited, did not include sites on Pescadero and 
San Gregorio Creeks (San Mateo County), and yielded 1,156 diagnostic 
elements, of which only five (0.4 percent) were salmonids (all 
steelhead which are the more abundant species in the area).'' The low 
number of salmonid remains discovered is likely due to the fact that 
salmonid bones do not preserve well due to higher porosity and are 
generally thinner than other bony fish (Gobalet et al., 2004). In fact, 
coho salmon have rarely been documented in archeological excavations 
within their known range in California, according to Gobalet et al. 
(2004). Coho salmon were only documented at archaeological sites in the 
eastern San Francisco Bay area and Del Norte county, despite the fact 
that the species is known to be native to streams in Marin, Sonoma,

[[Page 14686]]

Mendocino, and Humboldt counties. Due to the paucity of material 
collected in San Mateo and Santa Cruz counties, much more extensive 
sampling would be needed to use archaeological excavation findings as 
definitive evidence for establishing the presence or absence of coho 
salmon in the area. If coho salmon material exists in the 
archaeological excavations of the San Mateo and Santa Cruz County 
coasts at the same frequency as in the San Francisco Bay area (14 of 
105,000 elements), then at least 7,506 elements would have to be 
recovered and analyzed before a single coho salmon could be expected to 
be found (Gobalet et al., 2004).

Local Physical Conditions

    The petitioner also argues that the hydrologic, geologic, and 
climatic environments are so extreme in the streams south of San 
Francisco Bay that they preclude the long-term persistence of coho 
salmon because of the species' rigid 3-year life history. The available 
evidence does not support this argument. In fact, our Science Center 
has recently published an analysis predicting the potential for stream 
reaches within the geographic range of the CCC coho salmon ESU to 
exhibit habitat characteristics suitable for coho salmon during 
spawning or juvenile rearing as a function of the underlying 
geomorphological and hydrological characteristics of the landscape 
(NMFS, 2005b). This analysis, based on widely accepted fish-habitat 
relationships, uses indicators of geology, hydrology, precipitation, 
and climate (ambient air temperature) to express habitat conditions 
favorable to coho salmon. The analysis concludes that coastal streams 
south of San Francisco exhibit conditions favorable to coho salmon.
    While some localized habitat differences may exist between 
watersheds north and south of San Francisco Bay, we are unaware of any 
conclusive scientific evidence, and the petition does not offer any, 
that would lead one to conclude that these habitat differences are 
significant enough to preclude coho salmon presence south of San 
Francisco. While climatic conditions, erosive geology, and variable 
hydrology can be detrimental to coho salmon, these conditions are not 
unique to the area south of San Francisco and also occur in other 
portions of the geographic range of this ESU where coho salmon are 
acknowledged to be native and persistent.

Artificial Introduction

    The petition contends that coho salmon were first introduced to 
streams south of San Francisco Bay with the delivery of 50,000 coho 
salmon eggs from Baker Lake, Washington, to the Brookdale Hatchery on 
the San Lorenzo River in Santa Cruz county in 1906 (Bowers, 1906). The 
petition asserts that this introduction was the beginning of an effort 
to establish a coho salmon fishery which continues today and founded 
the coho salmon populations in San Mateo and Santa Cruz counties. The 
petition is correct in stating that coho salmon fry from sources 
outside of California have been planted in the streams south of San 
Francisco; however, coho salmon fry from sources within California and 
also from local watersheds have also been planted in these streams. 
Available evidence does not support the hypothesis that the out-of-
state Baker Lake introductions founded the coho salmon populations 
south of San Francisco Bay. In fact, juvenile coho salmon specimens 
were collected in 1895 from San Mateo and Santa Cruz counties and are 
currently housed in the CAS Ichthyological Collection (CAS, 2004). As 
discussed previously, we do not question the authenticity of these 
specimens. These collections occurred 11 years prior to the coho salmon 
egg deliveries from Baker Lake to the Brookdale Hatchery on the San 
Lorenzo River, and therefore, demonstrate coho presence in the area 
prior to any introductions from other areas.
    Available records of out-of-area coho salmon plantings prior to 
1911 indicate a total of 400,000 eggs were transferred over 5 years 
from Baker Lake to the Brookdale Hatchery and planted in unspecified 
Santa Cruz County stream locations between 1905 and 1910 (Bowers, 1906, 
1907, 1908, 1909, 1910). The number of Baker Lake eggs is relatively 
small and is not likely to have contributed to the coho salmon 
populations observed by Gilbert in 1910 (Smith, 1914). The Baker Lake 
coho salmon eggs were almost certainly planted as fry, which was the 
early practice of most hatcheries throughout California, including 
three plantings in Scott Creek from 1913 to 1930. This practice is no 
longer used by hatcheries because of the extremely poor survival rate 
of planted fry. Thus, it is likely that few if any of these planted 
fish survived to reproduce as adults, much less establish a new 
population in the area.
    Recent genetic evidence supports this point (NMFS, 2005a, 
unpublished memorandum). Molecular genetic data assembled and analyzed 
by the Southwest Fisheries Science Center's Santa Cruz Laboratory 
indicate coho salmon south of San Francisco Bay represent a historic 
part of the CCC coho salmon ESU (NMFS, 2005b) and are not the result of 
anthropogenic introductions (NMFS, 2005a, unpublished memorandum). 
These data are from two studies of genetic variation for 18 
microsatellite genes in coho salmon populations from the entire range 
of the species in California. These two studies include genotypes from 
more than 5,500 fish, an examination of the genetics of fish from 
various life stages and brood years, and systematic sampling to remove 
temporal and age-class variation. The 18 microsatellite genes are 
highly variable, with a total of almost 500 alleles, and provide 
sufficient information content to detect isolation between populations 
and insight into biogeographic patterns at multiple scales (NMFS, 
2005a, unpublished memorandum). Within this ESU, the studies found that 
all coho salmon populations south of San Francisco Bay are more closely 
related to each other than to any others, and their closest relatives 
are found in the populations just to the north of San Francisco Bay in 
Marin county. In some cases, alleles in coho salmon from San Mateo and 
Santa Cruz counties do not appear to be present in any other 
populations within the ESU. More generally, genetic structure within 
the CCC coho salmon ESU is one of isolation by distance, with genetic 
distance highly correlated with geographic distance. This is an 
equilibrium pattern that exists when populations are structured by 
adaptation-drift and distance-dependent migration acting together. The 
results are not consistent with the petitioner's claim that 
anthropogenic outplantings replaced lineages in the southern part of 
the range, or that these populations are non-native introductions 
(NMFS, 2005a, unpublished memorandum).
    These results suggest that, while coho salmon south of San 
Francisco have unique genetic characteristics, they nonetheless are 
clearly part of the CCC coho salmon ESU. These findings do not rule out 
the possibility that coho salmon populations in San Mateo and Santa 
Cruz counties may have received some genetic signals from the 
introduction of out-of-state or out-of-ESU fish; however, the number of 
unique alleles in the southern populations clearly demonstrates the 
genetic attributes of a native species at the edge of its range (NMFS, 
2005a, unpublished memorandum).

[[Page 14687]]

South of San Francisco Bay Populations and NMFS' Salmonid ESU Policy

    The original petition argued that the inclusion of coho populations 
south of San Francisco Bay in the listed CCC coho salmon ESU did not 
comport with NMFS' Salmonid ESU policy (56 FR 58612) because coho 
salmon in the area south of San Francisco were of exotic origin (i.e., 
originated from out-of-state or -ESU hatchery plantings), and, 
therefore, could not represent an important evolutionary legacy of the 
species. In recent correspondence to us, the petitioner advocated 
delisting the southernmost coho salmon populations (i.e., those south 
of San Francisco) based on the argument that these populations (even if 
native) are not evolutionarily significant to the CCC coho salmon ESU 
as a whole because they do not exhibit any unique phenotypic or life 
history traits or contribute to the ESU as a whole because they are 
biological sinks for the ESU. Based on these arguments, the petitioner 
has asserted that including these southern populations in the ESU is 
not consistent with NMFS' Salmonid ESU Policy (56 FR 58612), and that 
if the policy was properly applied, they would be excluded from the CCC 
coho salmon ESU. We believe the southern populations are of native 
origin based on the reasons discussed earlier and disagree with the 
petitioner's rationale and interpretation of our Salmonid ESU Policy. 
Much of the discussion in Waples (1991), the paper that NMFS' Salmonid 
ESU Policy was based on, is concerned with whether to designate a 
population or group of populations as an ESU and not, as advocated by 
the petitioner's representatives, whether or not to include or exclude 
a population that is part of an ESU. Waples (1991) argued that 
ephemeral populations should not be considered ESUs by themselves but 
should be included within the context of larger populations that will 
persist over evolutionary time frames. Using this rationale, every 
population of coho salmon needs to be included in some coho salmon ESU. 
We believe coho salmon south of San Francisco are part of the CCC coho 
salmon ESU, which represents an important component in the evolutionary 
legacy of the species. While it is uncertain as to whether or not all 
the populations in this area are dependent (sink) or independent 
(source) populations, their inclusion in the CCC coho salmon ESU is 
clearly in accordance with our Salmonid ESU policy.
    The petitioner has argued that sink populations contribute nothing 
to the ESU as a whole. We disagree with this assertion. A sink 
population is one that produces fewer recruits than spawners and 
receives more immigrants than the migrants it produces. Being a sink, 
however, is not the same as being a biological black hole which simply 
absorbs migrants and contributes nothing to the population. We believe 
inclusion of these southern populations (even if historically smaller 
relative to other populations within the ESU) in the CCC coho salmon 
ESU is appropriate because they are native populations within the 
species' historic range and contribute to the ESU as a whole. Finally, 
we believe protection and restoration of the coho salmon populations 
south of San Francisco Bay are essential to the conservation of this 
ESU as a whole because this geographic area is at the southernmost edge 
of the species distribution in North America and is likely to be a 
source of evolutionary innovation for the species.

Petition Finding

    After reviewing the information contained in the petition, we find 
that the petition does not present substantial scientific or commercial 
information indicating that the petitioned action may be warranted. In 
any case, even if the information presented by the petitioner were to 
have been considered to warrant further review, a review of additional 
scientific and commercial information regarding the description of the 
CCC coho salmon ESU indicates that the petitioned action is not 
warranted.

References

    Copies of the petition and related materials are available on the 
Internet at https://www.swr.noaa.gov, or upon request (see ADDRESSES 
section above)

    Authority: 16 U.S.C. 1531 et seq.

    Dated: March 17, 2006.
James W. Balsiger,
Acting Deputy Assistant Administrator for Regulatory Programs, National 
Marine Fisheries Service.
[FR Doc. E6-4192 Filed 3-22-06; 8:45 am]
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