Listing Endangered and Threatened Wildlife; 12-Month Findings on Petitions To List Spring-Run Oregon Coast Chinook Salmon and Spring-Run Southern Oregon and Northern California Coastal Chinook Salmon as Threatened or Endangered Under the Endangered Species Act, 45970-45974 [2021-17211]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 86, Number 156 (Tuesday, August 17, 2021)]
[Notices]
[Pages 45970-45974]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-17211]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No. 210806-0159]
RTID 0648-XW032 and 0648-XW013


Listing Endangered and Threatened Wildlife; 12-Month Findings on 
Petitions To List Spring-Run Oregon Coast Chinook Salmon and Spring-Run 
Southern Oregon and Northern California Coastal Chinook Salmon as 
Threatened or Endangered Under the Endangered Species Act

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

ACTION: Notice of 12-month petition findings.

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SUMMARY: We, NMFS, announce 12-month findings on 2 petitions to list 
populations of spring-run Chinook salmon (Oncorhynchus tshawytscha) as 
threatened or endangered Evolutionarily Significant Units (ESUs) under 
the Endangered Species Act (ESA) and to designate critical habitat 
concurrently with the listings. We have completed a comprehensive 
analysis of Oregon Coast (OC) and Southern Oregon and Northern 
California Coastal (SONCC) spring-run Chinook salmon populations in 
response to the petitions. Based on the best scientific and commercial 
data available, including the ESU configuration report, we have 
determined that listing the OC and SONCC spring-run Chinook salmon 
populations as threatened or endangered ESUs is not warranted. We 
determined that the OC and SONCC spring-run Chinook salmon populations 
do not meet the ESU Policy criteria to be considered ESUs separate from 
the OC and SONCC fall-run Chinook salmon populations and, therefore, do 
not meet the statutory definition of a species under the ESA. We also 
announce the availability of an ESU configuration report we prepared to 
inform our determination.

DATES: These findings were made on August 17, 2021.

ADDRESSES: The documents informing the 12-month findings, including the 
ESU configuration report (Ford et al. 2021), are available by 
submitting a request to the Assistant Regional Administrator, Protected 
Resources Division, West Coast Regional Office, 501 W Ocean Blvd., 
Suite 4200, Long Beach, CA 90802, Attention: OC and SONCC spring-run 
Chinook salmon 12-month Findings. The documents are also available 
electronically at https://www.fisheries.noaa.gov/protected-resource-regulations?title=&field_species_vocab_target_id=Chinook+Salmon&sort_by=field_relevant_date_value.

FOR FURTHER INFORMATION CONTACT: Gary Rule, NMFS West Coast Region at 
[email protected], (503) 230-5424; or Heather Austin, NMFS Office of 
Protected Resources at [email protected], (301) 427-8422.

SUPPLEMENTARY INFORMATION:

Background

    On September 24, 2019, the Secretary of Commerce received a 
petition from the Native Fish Society, Center for Biological Diversity, 
and Umpqua Watersheds (hereafter, the OC Petitioners) to list OC 
spring-run Chinook salmon as a threatened or endangered ESU under the 
ESA. Currently, OC spring-run Chinook salmon populations are part of 
the OC Chinook salmon ESU that combines populations of spring- and 
fall-run Chinook salmon and is not listed under the ESA. The OC 
Petitioners request that OC spring-run Chinook salmon be considered as 
a separate ESU and listed as threatened or endangered. The OC 
Petitioners also request the designation of critical habitat for OC 
spring-run Chinook salmon concurrent with ESA listing. On April 13, 
2020, we published a positive 90-day finding (85 FR 20476) (RTID 0648-
XW013) announcing that the petition presented substantial scientific or 
commercial information indicating that the petitioned action may be 
warranted. In our 90-day finding, we also announced the initiation of a 
status review to determine whether the spring-run populations of OC 
Chinook salmon constitute an ESU, and, if so, whether that OC spring-
run Chinook salmon ESU is in danger of extinction or likely to become 
so within the foreseeable future throughout all or a significant 
portion of its range; and we requested information to inform our status 
review.
    On May 4, 2020, the Secretary of Commerce received a petition from 
Richard K. Nawa (hereafter, the SONCC Petitioner, or Petitioners when 
referring collectively to the OC Petitioners and the SONCC Petitioner) 
to identify SONCC spring-run Chinook salmon as a separate ESU and list 
the ESU as threatened or endangered under the ESA. Currently, SONCC 
spring-run Chinook salmon populations are part of the SONCC Chinook 
salmon ESU that combines populations of spring- and fall-run Chinook 
salmon and is not listed under the ESA. The SONCC

[[Page 45971]]

Petitioner requests that SONCC spring-run Chinook salmon be considered 
as a separate ESU and listed as threatened or endangered. The SONCC 
Petitioner also requests the designation of critical habitat for SONCC 
spring-run Chinook salmon concurrent with ESA listing. On March 16, 
2021, we published a positive 90-day finding (86 FR 14407) (RTID 0648-
XW032) announcing that the petition presented substantial scientific or 
commercial information indicating that the petitioned action may be 
warranted. In our 90-day finding, we also announced the initiation of a 
status review to determine whether the spring-run populations of SONCC 
Chinook salmon constitute an ESU, and, if so, whether that SONCC 
spring-run Chinook salmon ESU is in danger of extinction or likely to 
become so within the foreseeable future throughout all or a significant 
portion of its range; and we requested information to inform our status 
review.

Listing Species Under the ESA

    We are responsible for determining whether species under our 
jurisdiction are threatened or endangered under the ESA (16 U.S.C. 1531 
et seq.). To make this determination, we first consider whether a group 
of organisms constitutes a ``species'' under section 3 of the ESA (16 
U.S.C. 1532), and then, if so, consider whether the status of the 
species qualifies it for listing as either threatened or endangered. 
Section 3 of the ESA defines species to include any subspecies of fish 
or wildlife or plants, and any distinct population segment (DPS) of any 
species of vertebrate fish or wildlife which interbreeds when mature. 
In 1991, we issued the Policy on Applying the Definition of Species 
Under the Endangered Species Act to Pacific Salmon (``ESU Policy''; 56 
FR 58612; November 20, 1991), which explains that a Pacific salmon 
population unit will be considered a DPS, and hence a ``species'' under 
the ESA, if it represents an ``evolutionarily significant unit'' of the 
biological species. The two criteria for delineating an ESU are: (1) It 
is substantially reproductively isolated from other conspecific 
population units; and (2) it represents an important component in the 
evolutionary legacy of the species. The ESU Policy is used exclusively 
for delineating distinct population segments of Pacific salmon. A joint 
NMFS-U.S. Fish and Wildlife Service (USFWS) (jointly, ``the Services'') 
policy clarifies the Services' interpretation of the phrase ``distinct 
population segment'' for the purposes of listing, delisting, and 
reclassifying a species under the ESA (``DPS Policy''; 61 FR 4722; 
February 7, 1996). In announcing this policy, the Services indicated 
that the ESU Policy for Pacific salmon was consistent with the DPS 
Policy and that NMFS would continue to use the ESU Policy for Pacific 
salmon.
    Section 3 of the ESA further 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. Thus, we 
interpret an ``endangered species'' to be one that is presently in 
danger of extinction. A ``threatened species,'' on the other hand, is 
not presently in danger of extinction, but is likely to become so in 
the foreseeable future. In other words, the primary statutory 
difference between a threatened and endangered species is the timing of 
when a species may be in danger of extinction, either presently 
(endangered) or in the foreseeable future (threatened).
    Section 4(a)(1) of the ESA also requires us to determine whether 
any species is endangered or threatened as a result of any of the 
following five factors: The present or threatened destruction, 
modification, or curtailment of its habitat or range; overutilization 
for commercial, recreational, scientific, or educational purposes; 
disease or predation; the inadequacy of existing regulatory mechanisms; 
or other natural or manmade factors affecting its continued existence 
(16 U.S.C. 1533(a)(1)(A)-(E)). Section 4(b)(1)(A) of the ESA requires 
us 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 by any 
state or foreign nation or political subdivision thereof to protect the 
species. In evaluating the efficacy of formalized domestic conservation 
efforts that have yet to be implemented or demonstrate effectiveness, 
we rely on the Services' joint Policy for Evaluation of Conservation 
Efforts When Making Listing Decisions (PECE; 68 FR 15100; March 28, 
2003).

Status Review

    As part of our review of the Petitioners' requests to delineate the 
OC and SONCC spring-run Chinook salmon ESUs and list them as threatened 
or endangered under the ESA, we formed an expert panel (Panel) 
consisting of scientists from NMFS Northwest Fisheries Science Center 
and Southwest Fisheries Science Center. We asked the Panel to provide: 
(1) An analysis and review of the Petitioners' claims that OC and SONCC 
spring-run Chinook salmon populations should be considered ESUs; and, 
if any new ESUs were identified, (2) a description of the demographic 
risks (i.e., abundance, productivity, spatial distribution and 
diversity) of the new ESUs. The first task was for the Panel to compile 
the best available scientific and commercial information relevant to 
re-evaluating the ESU structure of the OC and SONCC Chinook salmon 
ESUs, including information provided by the Petitioners. Specifically, 
the NMFS West Coast Region (WCR) requested the Panel use the criteria 
in the ESU Policy (56 FR 58612; November 20, 1991) to evaluate whether 
the OC and/or SONCC spring-run Chinook salmon populations should be 
considered ESUs. If the Panel concluded that one or both of the spring-
run Chinook salmon populations should be considered a separate ESU, and 
the WCR concurred, the Panel would complete the second task of 
describing the demographic risks, and submit their report on both tasks 
to the WCR. If the Panel concluded, and WCR concurred, that there 
should not be a change in the current ESU structure for either ESU 
(i.e., the spring-run Chinook salmon are part of the current ESU), the 
Panel would finalize their ESU structure findings and submit a report 
to the WCR. Under this second scenario, the Panel would not conduct a 
demographic risk analysis of the OC or SONCC spring-run Chinook salmon.
    In order to complete their ESU analysis, the Panel considered a 
variety of scientific information from the literature, unpublished 
documents, and direct communications with researchers working on the 
genetics of Chinook salmon, as well as information submitted to NMFS in 
response to the 90-day findings on the petitions. Information that was 
not previously peer-reviewed was formally reviewed by the Panel. The 
Panel evaluated the information provided by the Petitioners and 
considered additional factors that may contribute to our understanding 
of the evolutionary significance of run-timing in Chinook salmon.
    The Panel's draft report was subjected to independent peer review 
as required by the Office of Management and Budget (OMB) Final 
Information Quality Bulletin for Peer Review (M-05-03; December 16, 
2004). The draft report was peer reviewed by three independent 
specialists selected from the academic and scientific community, with 
expertise in the genetic diversity and biology of salmonids. The peer

[[Page 45972]]

reviewers were asked to evaluate the adequacy, appropriateness, and 
application of data used in the report. Of the three peer reviewers, 
two responded with written comments and the third responded informally 
that they had no comments. All peer reviewer comments were addressed 
prior to dissemination and finalization of the draft report and 
publication of these 12-month findings.
    We subsequently reviewed the report, its cited references, and peer 
review comments, and believe the report, which informs our 12-month 
findings, provides the best available scientific and commercial 
information on the OC and SONCC Chinook salmon ESUs. Much of the 
information discussed below is attributable to the report. However, in 
making the 12-month findings determination, we have independently 
applied the statutory provisions of the ESA, our regulations regarding 
listing determinations (50 CFR part 424), and our ESU Policy.

Previous Federal Actions

    On March 9, 1998, following completion of a comprehensive status 
review of Chinook salmon (O. tshawytscha) populations in Washington, 
Oregon, Idaho, and California, we published a proposed rule to list 
seven Chinook salmon ESUs as threatened or endangered under the ESA (63 
FR 11482). In this proposed rule, we identified the OC Chinook salmon 
ESU as comprised of coastal populations of spring- and fall-run Chinook 
salmon from the Elk River north to the mouth of the Columbia River (63 
FR 11482, March 8, 1998). We did not propose to list the OC ESU of 
Chinook salmon under the ESA, concluding that the ESU was neither in 
danger of extinction nor likely to become endangered in the foreseeable 
future.
    On September 16, 1999, following an updated status review for four 
Chinook salmon ESUs, we published a final rule to list two Chinook 
salmon ESUs as threatened under the ESA (64 FR 50394). In this 1999 
final rule, we identified the SONCC Chinook salmon ESU as composed of 
coastal populations of spring- and fall-run Chinook salmon from Euchre 
Creek, Oregon, through the Lower Klamath River, California (inclusive) 
(64 FR 50394, September 16, 1999). After assessing information 
concerning Chinook salmon abundance, distribution, population trends, 
and risks, and after considering efforts being made to protect Chinook 
salmon, we determined in this 1999 final rule that the SONCC ESU of 
Chinook salmon did not warrant listing under the ESA.

Evolutionary Significant Unit Analysis

    The Petitioners requested we delineate and list the OC and SONCC 
spring-run Chinook salmon populations as ESUs. As described above, the 
ESU Policy requires the consideration of two elements when deciding 
whether a population unit is an ESU: (1) It is substantially 
reproductively isolated from other conspecific population units; and 
(2) it represents an important component in the evolutionary legacy of 
the species. The first criterion, reproductive isolation, refers to 
restricted interbreeding among populations. Such isolation does not 
have to be absolute, but it must be strong enough to permit 
evolutionarily important differences to accrue in different population 
units. Information that can be useful in determining the degree of 
reproductive isolation includes documentation of fish straying from one 
population to another, recolonization rates of other populations, the 
efficacy of natural barriers to migration, and measurements of genetic 
differences between populations. Each of these types of information has 
its limitations. Identification of physical barriers to genetic 
exchange can help define the geographic extent of distinct populations 
but reliance on physical features alone can be misleading in the 
absence of supporting biological information. Documentation of straying 
between populations can provide information about the movements of 
individual fish but not the genetic consequences of migration. 
Furthermore, measurements of current straying or recolonization rates 
provide no direct information about the magnitude or consistency of 
such rates in the past. In this respect, data from the analysis of 
genetic variation between individuals or groups of fish can be very 
useful because they reflect levels of gene flow that have occurred over 
evolutionary time scales.
    To be considered an ESU, the population must also represent an 
important component in the evolutionary legacy of the species. The 
evolutionary legacy of a species is the genetic variability that is a 
product of past evolutionary events and which represents the reservoir 
upon which future evolutionary potential depends. This second criterion 
would be met if the population contributed substantially to the 
ecological/genetic diversity of the species as a whole. In other words, 
if the population became extinct, would this event represent a 
significant loss to the ecological/genetic diversity of the entire 
species? In making this determination, the following questions are 
relevant:
    1. Is the population genetically distinct from other conspecific 
populations?
    2. Does the population occupy unusual or distinctive habitat?
    3. Does the population show evidence of unusual or distinctive 
adaptation to its environment?
    Several types of information are useful in addressing these 
questions. Again, the strengths and limitations of the information will 
be considered in making the determination. Phenotypic/life-history 
traits, such as size, fecundity, and age and time of spawning may 
reflect local adaptations of evolutionary importance, but 
interpretation of these traits is complicated by their sensitivity to 
environmental conditions. Data from DNA analysis provides valuable 
insight into levels of overall genetic differentiation among 
populations but in many cases does not contain direct information 
regarding the extent of adaptive genetic differences. Habitat 
differences suggest the possibility for local adaptations but do not 
prove that such adaptations exist.

Methods for Analyzing Genetic Variation

    Genetic variability within and between populations of Chinook 
salmon generally falls into two categories: Neutral and adaptive 
genetic variation. Most of the variation in a species' genome (the sum 
total of an organism's DNA) has no influence on survival or 
reproduction, and hence is considered to be selectively neutral. 
Examining patterns of selectively neutral variation among individuals 
in populations is very useful for understanding the relationships 
between those individuals and the histories of the populations. For 
example, neutral variation can be used to estimate the degree of gene 
flow or interbreeding among different populations, or the familial 
relationships among specific individuals. Adaptive genetic variation 
refers to genes or regulatory regions of the genome that have an effect 
on fitness (survival or reproduction). Adaptive genetic variation 
occurs when certain DNA sequence variants in a population help some 
members survive or reproduce better than others.

Reproductive Isolation Criterion

    The 1998 and 1999 coastwide status reviews for Chinook salmon 
focused on patterns of neutral genetic variation and did not consider 
differences in run timing (adaptive genetic variation) alone to be 
indicative of substantial

[[Page 45973]]

reproductive isolation. This conclusion was due in part to the observed 
patterns of genetic variation, in which spring-run and fall-run fish 
spawning in the same or nearby rivers were genetically similar to each 
other and more similar to each other than to populations of either run 
type spawning in geographically distant rivers (Myers et al. 1998; 
Busby et al. 1999). The Panel reviewed subsequent genetic studies and 
found that they clearly confirm the earlier findings that, as a group, 
coastal spring-run Chinook salmon are not a distinct evolutionary 
lineage within the species, but rather share their evolutionary history 
and most of their genetic variation with the fall-run Chinook salmon 
spawning in the same and nearby rivers. In other words, the patterns of 
genetic variation coastwide indicate that spring-run Chinook salmon 
spawning in different rivers are generally more differentiated from 
each other than they are to co-occurring fall-run Chinook salmon.
    Although this pattern is apparent when viewed on a coastwide scale, 
it is important to note that most of the coastwide Chinook salmon 
genetic studies conducted over the past two decades had few samples 
from the OC and SONCC areas. The Oregon Department of Fish and Wildlife 
identified up to nine rivers in the currently defined OC Chinook salmon 
ESU as having either spring-run populations or a spring-run or summer-
run component to a population, but no genetics study has included more 
than three spring-run or summer-run population samples, and spring-run 
or summer-run samples have only been analyzed for a total of four OC 
river systems: Nehalem, Trask, Siletz, and Umpqua rivers. Following a 
review of the available information, the Panel found that some of the 
samples from co-occurring spring-run and fall-run populations in the OC 
areas do not necessarily seem to be closely genetically related. In 
particular, Umpqua River spring-run (sampled from the Rock Creek 
hatchery) tend to cluster with SONCC samples of both run types in a 
number of studies rather than with Umpqua fall-run samples or other OC 
fall-run samples (Myers et al. 1998; Waples et al. 2004; Seeb et al. 
2007; Narum et al. 2008; Clemento et al. 2014; Hecht et al. 2015; note 
that some studies used the same set of samples so these data are not 
all independent). This pattern could indicate that Umpqua River spring-
run Chinook salmon are in fact historically more closely related to 
SONCC Chinook salmon, or could be a result of past broodstock transfers 
from the Rogue River (and elsewhere) into the Rock Creek Hatchery (as 
summarized by Myers et al. 1998, Appendix D). In addition, fall-run 
samples from the Trask River Hatchery were more closely related to 
other OC fall-run samples than to Trask River Hatchery spring-run 
samples (Beacham et al. 2006). A similar pattern was seen in wild fall-
run and spring-run Chinook salmon from the Siletz River (Davis et al. 
2017). Extensive out-of-basin spring-run (and fall-run) Chinook salmon 
hatchery releases in the Trask River may be an explanation for this 
pattern. Similarly, although relatively few spring-run Chinook salmon 
hatchery releases have occurred in the Siletz River, that basin did 
receive more than 2 million Columbia River hatchery Chinook salmon 
releases between 1934 and 1952 (Myers et al. 1998, Appendix D). 
Additional sampling and genetic analysis of natural-origin fish across 
the range of return timing in multiple OC and SONCC rivers would help 
improve our understanding of the genetic relationships among OC and 
SONCC Chinook salmon populations. However, the available data does not 
indicate that spring-run Chinook salmon spawning in rivers on the 
Oregon Coast, as a group, form a distinct lineage separate from OC 
fall-run Chinook salmon.
    The SONCC area is more thoroughly sampled, particularly with 
respect to the Rogue River basin. Within the SONCC ESU, it is apparent 
that the close genetic relationship between geographically proximate 
spring-run and fall-run Chinook salmon continues to be true when viewed 
at the within-ESU scale. In particular, in several studies, spring-run 
and fall-run samples from the Rogue River are more genetically related 
to each other than either are to samples from other rivers in the SONCC 
ESU. In other words, within the currently delineated SONCC Chinook 
salmon ESU, spring-run and fall-run fish spawning in the Rogue River 
appear to reproduce more with each other than with fall-run fish 
spawning in other rivers in the ESU. The Panel found that this pattern 
is similar to what has been reported in the Upper Klamath and Trinity 
Rivers (Anderson and Garza 2018), and is also apparent in the Puget 
Sound and Lower Columbia Chinook ESUs.
    In addition to neutral genetic variation, adaptive genetic 
variation has been used to identify differences between individual fish 
or groups of fish. An example is the gene-region that has been 
associated with run-timing in Chinook salmon and steelhead, the GREB1L 
gene (otherwise referred to as the GREB1L region of the genome). Hess 
et al. (2016), Prince et al. (2017) and Thompson et al. (2019a) 
characterized the GREB1L region as two alleles (different forms) and 
three genotypes (different combinations of the two alleles): 
Individuals with two early run-timing alleles (early run homozygotes), 
individuals with two late run-timing alleles (late run homozygotes), 
and individuals with one allele for the early and one for the late run-
timing (heterozygotes). There are five recent studies that have 
examined run-time-associated variants in the GREB1L region in OC and 
SONCC Chinook samples (Prince et al. 2017; Anderson & Garza 2018; 
Thompson et al. 2019a; O'Malley et al. 2020a; O'Malley et al. 2020b). 
These studies have found that heterozygotes are common, indicating that 
interbreeding between fish homozygous for the spring-run and fall-run 
variants is commonly occurring. This pattern has been extensively 
studied in the Rogue River basin of the SONCC ESU (Thompson et al. 
2019; O'Malley et al. 2020a; O'Malley et al. 2020b), where researchers 
have obtained relatively large sample sizes of fish based on carcass 
surveys and surveys of captured live fish conducted throughout the run. 
For the OC, the only river that has been sampled using the GREB1L 
markers is the Siletz River (Anderson and Garza 2018; Thompson et al. 
2020). That study also found substantial proportions of heterozygotes, 
particularly among fish that returned to the river early and were 
identified as spring-run (29 percent). A similarly high proportion of 
GREB1L region heterozygotes have been found in other coastal Chinook 
salmon ESUs (Upper Klamath River, Anderson and Garza 2018; Rogue River, 
Thompson et al. 2019a; Washington Coast, Thompson et al. 2019b).
    The GREB1L region has been demonstrated to be highly associated 
with run timing in multiple populations of coastal Chinook salmon 
(i.e., coastal spring-run Chinook salmon are homozygous for the early 
alleles, and fall-run Chinook are homozygous for the late alleles--
Anderson and Garza 2018, Thompson et al. 2019a,b, O'Malley et al. 2020, 
Thompson et al. 2020). The finding of substantial proportions of 
heterozygotes provides evidence of contemporary interbreeding between 
alternative homozygotes at the GREB1L region. This, in turn, implies 
that mating among spring-run and fall-run (and likely intermediate 
timed) fish is common in multiple watersheds (reviewed by Ford et al. 
2020). Analysis of recombination events (Anderson and Garza 2018, 
Thompson et al. 2020) also indicates that at least in the Upper

[[Page 45974]]

Klamath River, such interbreeding must have also occurred historically 
at some level, although the rate of interbreeding was not determined 
and could be lower than is seen now.
    In both the OC and the SONCC ESUs, there is therefore strong 
evidence from GREB1L region markers that interbreeding between spring-
run and fall-run Chinook salmon is common, at least for the two 
watersheds that have been studied to date (Rogue River, Siletz River). 
However, the data do not indicate whether the current levels of 
interbreeding occurred historically under more pristine conditions. 
Patterns of random genomic variation (indicative of population history) 
indicate that spring-run Chinook salmon in the OC and SONCC ESUs are, 
as a group, not substantially reproductively isolated from fall-run 
Chinook spawning in the OC and SONCC rivers. There is some indication 
that spring-run Chinook salmon in the Umpqua River may have somewhat 
reduced gene flow from other OC fall-run and spring-run Chinook salmon 
populations, but past hatchery practices may have also influenced this 
result. As a whole, however, the available data indicate that the 
spring-run portions of the OC and SONCC ESUs are not substantially 
reproductively isolated from the fall-run populations in the ESUs. 
Additional genetic sampling of fish throughout the period of migration 
in multiple populations, especially in the OC ESU, would be very 
helpful for further evaluating this question.

Evolutionary Legacy Criterion

    The early run-timing trait is an important component of diversity 
within the Chinook salmon species. In particular, the trait allows 
Chinook salmon to access upstream habitats that are inaccessible to 
later returning fish in some years. Run time diversity as a whole is 
also expected to increase viability by broadening the portfolio of 
traits within a species or an ESU, which leads to increased resilience 
to environmental variation (Quinn et al. 2016). Recent reviews of ESU/
DPS configurations of Chinook salmon (Anderson et al. 2018) and 
steelhead (Pearse et al. 2019) support this point, as does a recent 
expert workshop report (Ford et al. 2020) and the original coastwide 
status review of Chinook salmon (Myers et al. 1998). Recovery plans for 
Chinook salmon ESUs that contain populations with both spring-run and 
fall-run fish also emphasize the importance of recovering populations 
with both life-history strategies (Shared Strategy Development 
Committee 2007; Dornbush 2013; Pearse et al. 2019).
    While recognizing the importance of run-timing variation to species 
and ESU viability, Myers et al. (1998) concluded that patterns of 
genetic variation and patterns of variation for other life-history 
traits indicated that coastal spring- and fall-run Chinook salmon 
shared the same recent evolutionary history. Coastal ESUs were 
identified based on concordant patterns of genetic, life-history, and 
geographic variation, with run-timing variation considered to be an 
important element of diversity within ESUs. Subsequent reports of Upper 
Klamath Trinity River Chinook salmon and Northern California steelhead 
have reached the same conclusion (Williams et al. 2013, Anderson et al. 
2018, Pearse et al. 2019). Recent genetic studies have greatly 
increased our knowledge of the genetic basis of run-timing variation, 
but these studies do not change or invalidate the previous conclusion 
that spring-run and fall-run Chinook salmon in the currently delineated 
OC and SONCC Chinook salmon ESUs share a recent evolutionary legacy, 
and they are, on the whole, more genetically similar to each other than 
to populations in other ESUs. The two run types display similar 
characteristics in other life-history traits, and are genetically 
similar to each other due to a combination of recent common ancestry 
and ongoing interbreeding. Identifying a spring-run-only Chinook salmon 
ESU for either the OC or SONCC areas would therefore be inconsistent 
with our ESU policy, both because of high levels of interbreeding 
between spring-run and fall-run fish in these ESUs and because spring-
run fish, as a group, in these ESUs do not form a distinct evolutionary 
lineage within the species.

Conclusions on the Evolutionarily Significant Unit Analysis

    The Panel concluded, and the WCR concurred, that the best available 
information indicates that OC and SONCC spring-run Chinook salmon 
populations do not meet the reproductive isolation and genetic legacy 
criteria of the ESU Policy. The spring-run phenotype and the spring-run 
variant within the GREB1L chromosomal region are clearly an important 
part of the diversity within the Chinook salmon species, but the 
available data indicate that spring-run Chinook salmon in the OC and 
SONCC ESUs regularly interbreed with and share a recent evolutionary 
history throughout the vast majority of their genome with fall-run 
Chinook salmon in the same rivers.

Final Determination

    Section 4(b)(1) of the ESA requires that NMFS make listing 
determinations 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 by any state or 
foreign nation, or political subdivisions thereof, to protect and 
conserve the species. We have independently reviewed the best available 
scientific and commercial information, including the information 
provided in the petitions and public comments submitted on the 90-day 
findings (85 FR 20476, April 13, 2020; 86 FR 14407, March 16, 2021), 
the ESU configuration review report, and other published and 
unpublished information, and have consulted with species experts and 
individuals familiar with the OC and SONCC Chinook salmon ESUs.
    Our determination set forth here is based on a synthesis and 
integration of the foregoing information. Based on our consideration of 
the best available scientific and commercial information, as summarized 
here and in the ESU configuration report, we conclude that OC and SONCC 
spring-run Chinook salmon populations do not constitute ESUs. 
Accordingly, OC and SONCC spring-run Chinook salmon populations do not 
meet the statutory definition of a species, and thus, OC and SONCC 
spring-run Chinook salmon populations do not warrant listing under the 
ESA.
    This is a final action, and, therefore, we are not soliciting 
public comments.

References

    A complete list of all references cited herein is available upon 
request (see FOR FURTHER INFORMATION CONTACT).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: August 6, 2021.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
[FR Doc. 2021-17211 Filed 8-16-21; 8:45 am]
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