Endangered and Threatened Wildlife and Plants; Removal of the Apache Trout From the List of Endangered and Threatened Wildlife, 72739-72757 [2024-19330]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 89, Number 173 (Friday, September 6, 2024)]
[Rules and Regulations]
[Pages 72739-72757]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19330]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2022-0115; FXES1113090FEDR-245-FF09E22000]
RIN 1018-BG94


Endangered and Threatened Wildlife and Plants; Removal of the 
Apache Trout From the List of Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service or USFWS), are 
removing the Apache trout (Oncorhynchus apache), a fish native to 
Arizona, from the Federal List of Endangered and Threatened Wildlife. 
Our review indicates that the threats to the Apache trout have been 
eliminated or reduced to the point that the species no longer meets the 
definition of an endangered or threatened species under the Endangered 
Species Act of 1973, as amended (Act). Accordingly, the prohibitions 
and conservation measures provided by the Act, particularly through 
section 4 and 7, will no longer apply to the Apache trout.

DATES: This rule is effective October 7, 2024.

ADDRESSES: The proposed rule and this final rule, the post-delisting 
monitoring plan, the comments we received on the proposed rule, and 
supporting documents are available at https://www.regulations.gov under 
Docket No. FWS-R2-ES-2022-0115.

FOR FURTHER INFORMATION CONTACT: Heather Whitlaw, Field Supervisor, 
Arizona Ecological Services Office, U.S. Fish and Wildlife Service, 
9828 North 31st Ave #C3, Phoenix AZ 85051-2517; telephone 602-242-0210, 
[email protected]. Individuals in the United States who are deaf, 
deafblind, hard of hearing, or have a speech disability may dial 711 
(TTY, TDD, or TeleBraille) to access telecommunications relay services. 
Individuals outside the United States should use the relay services 
offered within their country to make international calls to the point-
of-contact in the United States.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species warrants 
removal from the Federal Lists of Endangered and Threatened Wildlife 
and Plants if it

[[Page 72740]]

no longer meets the definition of an endangered species (in danger of 
extinction throughout all or a significant portion of its range) or a 
threatened species (likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range). The Apache trout is listed as threatened, and we are delisting 
it because we have determined it does not meet the Act's definition of 
an endangered or threatened species. Delisting a species can be 
completed only by issuing a rule through the Administrative Procedure 
Act rulemaking process (5 U.S.C. 551 et seq.).
    What this document does. This rule removes the Apache trout from 
the List of Endangered and Threatened Wildlife (List) due to the 
species' recovery.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered species or a threatened species because of any 
of five factors: (A) The present or threatened destruction, 
modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. The determination to delist a 
species must be based on an analysis of the same factors.
    Under the Act, we must review the status of all listed species at 
least once every five years. We must delist a species if we determine, 
on the basis of the best available scientific and commercial data, that 
the species is neither a threatened species nor an endangered species. 
Our regulations at 50 CFR 424.11(e) identify four reasons why we might 
determine a species shall be delisted: (1) The species is extinct, (2) 
the species has recovered to the point at which it no longer meets 
thedefinition of an endangered species or a threatened species, (3) new 
information that has become available since the original listing 
decision shows the listed entity does not meet thedefinition of an 
endangered species or a threatened species, or (4) new information that 
has become available since the original listing decision shows the 
listed entity does not meet thedefinition of a species. Here, we have 
determined that the Apache trout has recovered to the point at which it 
no longer meets the definition of an endangered species or a threatened 
species; therefore, we are delisting it.
    Specifically, our analysis indicates that the Apache trout now 
consists of multiple, sufficiently resilient populations across 
subbasins encompassing a large percentage of the species' historical 
range. Due to conservation efforts undertaken to date, the Apache trout 
now encompasses 30 confirmed genetically pure populations across 3 
basins and 6 subbasins. Twenty-five of the 30 pure populations of 
Apache trout are located in whole (22) or in part (3) on Tribal lands, 
where longstanding policy has and will continue to result in 
significant protections of the watersheds and these populations.
    We consider the Apache trout to be a conservation-reliant species, 
which we define in this case as a species that has met recovery 
criteria but requires continued active management to sustain the 
species and associated habitat in a recovered condition (see Scott et 
al. 2010, entire), given that the Apache trout requires active 
management to maintain suitable habitat. To address this management 
need for conservation activities to address long-term management of 
this species, the Arizona Game and Fish Department (AZGFD), White 
Mountain Apache Tribe (WMAT), the U.S. Forest Service (USFS), Trout 
Unlimited, and the Service developed, and are implementing, the Apache 
trout Cooperative Management Plan (CMP; USFWS 2021, entire) and are 
committed to the continuing long-term management of this species. 
Management of conservation barriers and removal of nonnative trout 
following the CMP, which will not be impacted by this delisting 
determination, will ensure that the Apache trout maintains sufficient 
resiliency, redundancy, and representation to maintain viability into 
the future.

Previous Federal Actions

    Please refer to the proposed rule to delist the Apache trout 
published on August 11, 2023, (88 FR 54548) for a detailed description 
of previous Federal actions concerning this species.

Peer Review

    A species status assessment (SSA) team prepared an SSA report for 
the Apache trout (USFWS 2022a, entire). The SSA team was composed of 
Service biologists, in consultation with other species experts from 
WMAT, AZGFD, USFS, and Trout Unlimited. The SSA report represents a 
compilation of the best scientific and commercial data available 
concerning the status of the species, including the impacts of past, 
present, and future factors (both negative and beneficial) affecting 
the species.
    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 
2016, memorandum updating and clarifying the role of peer review of 
listing and recovery actions under the Act, we solicited independent 
scientific review of the information contained in the Apache trout SSA 
report. As discussed in the proposed rule, we sent the SSA report to 
three independent peer reviewers and received three responses. The peer 
reviews can be found at https://www.regulations.gov. In preparing the 
proposed rule, we incorporated the results of these reviews, as 
appropriate, into the SSA report, which was the foundation for the 
proposed rule and this final rule. A summary of the peer review 
comments and our responses can be found in the proposed rule (88 FR 
54548; August, 11, 2023).

Summary of Changes From the Proposed Rule

    In preparing this final rule, we reviewed and fully considered all 
comments we received during the comment period from the peer reviewers 
and the public on the proposed rule to reclassify the Apache trout. 
Minor, nonsubstantive changes and clarifications were made to the SSA 
report and this final rule in response to comments. The information we 
received during the peer review and public comment period on the 
proposed rule did not change our analysis, rationale, or determination 
for delisting the Apache trout. Below is a summary of the 
clarifications made in this final rule.
    (1) We made revisions to the Recovery Plan Implementation, below, 
to provide more clarity on various management and conservation actions 
that have been taken to benefit the Apache trout. With regard to 
management of the Apache trout and Apache trout habitat, we clarified 
that: projects on Apache Sitgreaves National Forest (ASNF) lands 
require National Environmental Policy Act review; and the WMAT, AZGFD, 
ASNF, USFWS, and Trout Unlimited are all signatories to the 2021 Apache 
Trout Cooperative Management Plan (USFWS 2021, entire).
    (2) We included recent confirmation of the one population listed as 
``pure-suspected'' in the SSA report. This population has been analyzed 
and was found to be genetically pure since the publication of the 
proposed rule on August 11, 2023 (88 FR 54548) (Mussmann 2024, pers. 
comm.).
    (3) We noted ``put-and-take opportunities'' provided by AZGFD and 
WMAT that are intended to generate

[[Page 72741]]

public support for Apache trout recovery.
    (4) We clarified that Apache trout recovery streams on Tribal lands 
have not and will not be opened for angling in the future according to 
longstanding Tribal policy.
    (5) Finally, we included information on our post-delisting 
monitoring (PDM) plan (Dauwalter et al. 2024, entire) that will start 
once the Apache trout is delisted. This plan will be managed and 
adhered to by the Service and its partners for at least 10 years. 
Specifically, the PDM plan prescribes for monitoring of Apache trout 
abundance and for ongoing assessments of conservation barrier 
effectiveness.

Summary of Comments and Recommendations

    In the proposed rule published on August 11, 2023 (88 FR 54548), we 
requested that all interested parties submit written comments on the 
proposal by October 10, 2023. We also contacted appropriate Federal and 
State agencies, Tribal entities, scientific experts and organizations, 
and other interested parties and invited them to comment on the 
proposal. A newspaper notice inviting general public comment was 
published in the White Mountain Independent on August 18, 2023. We did 
not receive any requests for a public hearing. All substantive 
information received during the comment period has either been 
incorporated directly into this final determination or is addressed 
below.

Public Comments

    We reviewed all public comments for substantive issues and new 
information regarding the species. Substantive comments we received 
during the comment period are addressed below.
    (1) Comment: Three commenters expressed opposition to delisting the 
Apache trout based on the projected effects of climate change and 
associated effects on Apache trout habitat. The noted effects include 
reduced habitat suitability, diminished stream volume, and less 
precipitation. Two commenters cited recent peer-reviewed published 
projections by Dauwalter (2023 et al., entire) that apply these effects 
specifically to Apache trout and regionally to the southwestern United 
States. The third commenter stated that the implication of warmer 
upstream temperatures being a benefit to Apache trout populations in 
those portions of streams was incorrect.
    Our response: The SSA report examined in depth the effects of 
climate change and associated effects on Apache trout habitat and did 
not find these effects to impact the resiliency of the species in the 
foreseeable future. Specifically, as we stated in the SSA report (USFWS 
2022a, pp. 51, 135-140), the model suggests that most streams currently 
occupied by Apache trout, or those currently unoccupied but designated 
as recovery streams, are not temperature limited. Suitability only 
improves when 2080s projections of temperature alone are considered, 
because some headwater reaches appear to be too cold, currently, for 
occupancy. That is, cold temperatures can be limiting to Apache trout 
populations in some streams, and any warming may benefit them in 
headwater reaches--at least until the 2080s. It is only when future 
changes in precipitation are considered, as well, that habitat 
suitability decreases during the 2080s. Many habitat patches that are 
currently occupied by the species are projected to remain suitable into 
the 2080s, which suggests their resiliency is only limited by the size 
of the patch they currently occupy (Peterson et al. 2014, pp. 564-268; 
Isaak et al. 2015, pp. 2548-2551). In the Summary of Biological Status 
and Threats section of this final rule, we expanded our discussion of 
climate change as a threat.
    In response to the reference to Dauwalter (2023, entire), we note 
that the cited manuscript was based on appendix C of the SSA report 
(USFWS 2022a, pp. 133-137) and was published by Apache trout SSA core 
team members following completion of the SSA report. Dauwalter et al. 
(2023, entire) noted that most Apache trout populations are isolated 
upstream of barriers to nonnative trout in stream reaches that are 
currently thermally suitable with respect to mean July temperatures and 
concluded those habitats would remain suitable into the 2080s. Cold 
headwater reaches are projected to warm, becoming more suitable in the 
2080s. Thus, intentional isolation and the resultant truncated 
downstream distributions of Apache trout populations in headwater 
streams explain the nominal effect of projected temperature increases 
due to climate change on this cold-adapted salmonid. Standardized model 
parameters suggest that future declines in precipitation, manifested 
through reduced snowpack and its influence on streamflows, will play a 
larger role than temperature in the suitability--and, thus, 
resiliency--of Apache trout habitats at least into the 2080s.
    (2) Comment: Two commenters stated that the delisting is premature 
because of impacts to Apache trout habitat caused by grazing by horses 
and livestock. Examples of these impacts may include eroded soils and 
streambanks, damaged riparian vegetation, widening of streams, effects 
on water depth and temperature, and contamination of streams by fecal 
material. One commenter stated that current land management plans by 
the USFS are inadequate to address these impacts. They further 
identified the western Black River watershed as a particular location 
where severe stream degradation has occurred due to grazing by horses 
on Tribal land.
    Our response: Stream habitat quality was assessed and classified in 
the Current Conditions section of the SSA report (USFWS 2022a, pp. 61-
96) and these assessments considered and reflected impacts from 
stochastic events (e.g., wildfire) and a variety of anthropogenic 
factors (e.g., road crossings, developed floodplains, logging, animal 
use). The SSA report section on Future Conditions (USFWS 2022a, pp. 97-
106) included analysis of future conditions from environmental change 
and management actions and the projected influences on the species' 
ability to sustain populations in the wild over defined timeframes. 
Thirty-seven distinct threat factors were considered in this analysis, 
with Apache trout experts considering continued conservation actions 
(e.g., barrier construction and maintenance, chemical and mechanical 
removal of invasive species, habitat restoration, watershed management) 
and wildfires as the most important factors affecting the future 
condition of the Apache trout.
    Grazing management was ultimately ranked as the 14th most important 
factor affecting the future condition of Apache trout. There are few 
livestock grazing allotments associated with Apache trout recovery 
streams, and the USFS engages in active management to remove feral 
horses and stray cattle where they occur outside of authorized areas. 
There are areas where habitat quality has been degraded by legacy 
grazing and other anthropogenic factors, especially in sensitive wet 
meadow habitats. In addition, Apache trout recovery partners are 
currently pursuing funding to address degraded habitats with ungulate 
exclosure areas, riparian plantings, and instream habitat restoration 
projects. Current proposals are focused on the Black River and Little 
Colorado River watersheds along Burro, Centerfire, Hayground, and 
Thompson creeks and South Fork Little Colorado River. Funding has 
already been secured and projects begun on Boggy/Lofer and Flash creeks 
on Tribal lands. Additionally, it is important to emphasize that 
despite certain degraded habitats, due in part to possible

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anthropogenic factors including grazing that have been in place since 
the species was listed, populations of the species have grown to meet 
the recovery criteria. Accordingly, we find that because the species 
met recovery criteria despite the effects of grazing activities, and 
because ongoing and future restoration projects and active grazing 
management will decrease the effects of this stressor in the future, 
delisting is not premature due to potential impacts of grazing.
    (3) Comment: One commenter stated that populations under 500 
individuals are at higher risk from demographic and genetic 
stochasticity, as well as stochastic events such as stream drying, 
fire, inbreeding, and low genetic variation.
    Our response: The population estimates presented in the SSA report 
are strictly estimates of adult population size. Total population size 
estimates, which are available for some populations, are generally much 
larger than the estimates of adult population size presented in the SSA 
report. Although we contend that there is uncertainty about the exact 
threshold under which Apache trout populations are at higher risk from 
stochastic events, we generally agree with this comment, which is why 
this concept was discussed in the SSA report's Executive Summary 
section on resiliency (USFWS 2022a, p.7), as well as the sections on 
population size (USFWS 2022a, p.43), effective population size (USFWS 
2022a, p.44), habitat connectivity and metapopulation dynamics (USFWS 
2022a, p.45), habitat factors (USFWS 2022a, p.75), and population 
resiliency (USFWS 2022a, p.78).
    (4) Comment: One commenter stated that the 30-year, 6-generation 
timeframe used for our future condition analysis is arbitrary and not 
based on anything biologically meaningful. They stated that we have 
used longer timeframes when analyzing the effects of climate change and 
other long-term impacts for other species' classification analyses.
    Our response: The SSA framework documentation suggests that a 
meaningful timeframe should encompass multiple generations when 
considering a species' future condition and status (USFWS 2016, p. 18). 
We found that 30 years, or 6 generations of the Apache trout is a 
meaningful timeframe in which to analyze future condition because 
within this timeframe it is likely that the primary threats of 
nonnative trout and climate change will continue to be relevant to the 
species and it is biologically reasonable to assess the species' 
response to these threats within this timeframe. We have a high level 
of confidence in the results of our analysis of these threats and 
responses within this timeframe, and our confidence in the results of 
an analysis extended beyond this timeframe decreases. Additionally, 
this timeframe allows us to reasonably forecast upcoming management 
activities as they will be implemented through the CMP.
    (5) Comment: One commenter stated that the information and data we 
used to assess stream temperatures are outdated and that predicted 
higher stream temperatures will lead to an increase of invasive trout 
species in Apache trout streams.
    Our response: We used the best available in situ temperature 
monitoring data collected by the Apache-Sitgreaves National Forests on 
Apache trout recovery streams (2013-2018) and a widely-used stream 
temperature model (NorWeST; Isaak et al. 2017, entire) that contained 
projections into the 2080s (GCM projections of a ten-model ensemble and 
A1B emissions scenario; Isaak et al. 2017) to understand future habitat 
suitability--an approach that was subjected to peer review and was 
published (Dauwalter et al. 2023, entire).
    Thermal tolerances between trout species are similar, and recovery 
streams are suitable at this time and expected to remain so well into 
the future. We view invasive trout as one of the primary ongoing 
threats to this species and have developed short- and long-term plans, 
which are described in the CMP and Apache Trout Monitoring Plan, to 
monitor for and manage this threat long-term (Apache Trout CMP 
Workgroup 2021, entire; Dauwalter et al. 2024, entire). Since 2015, 
recovery partners have eradicated invasive trout in Crooked and Flash 
creeks, and likely eradicated them from Aspen (formerly Squaw) and 
Paradise creeks during 2022. Much progress has been made in suppressing 
brook trout in the upper West Fork Black River population area, and in 
2023, YY-male brown trout stocking began to ensure success of this 
effort. Additional nonnative trout removal projects will begin as the 
ongoing projects are completed.
    In addition to these projects, recovery partners are supporting 
efforts to develop a YY-male brown trout broodstock for future use in 
eradication projects. Construction of a new conservation barrier on Big 
Bonito Creek has begun, and engineering designs for new conservation 
barriers on Aspen, Crooked/Boggy/Lofer, Flash, Little Bonito, Little 
Diamond/Coyote, Ord, Paradise, and Wohlenberg creeks have been acquired 
or are expected to be finalized during 2024. Finally, both the CMP and 
the Apache Trout Monitoring Plan (Apache Trout CMP Workgroup 2021, 
entire; Dauwalter et al. 2024, entire) detail our future invasive trout 
surveillance and Apache trout monitoring plans.
    (6) Comment: One commenter stated that the SSA report indicates 
that 11 of 31 Apache trout streams lack evidence of hybridization with 
other trout species, however the proposed rule does not discuss this.
    Our response: Table 11 in the SSA report (USFWS 2022a pp. 8-9) 
shows that 29 populations are ``pure-tested'' with another ``pure-
suspected.'' Tissue samples from the ``pure-suspected'' population were 
collected and submitted for genetic analyses, and preliminary results 
indicate genetic purity of this population as well (Mussman pers. comm. 
2024). Table 15 in the SSA report (USFWS 2022a, p. 104) also 
demonstrates the same information: there are 29 populations with a 
genetic score of 4 (pure-tested) and 1 with a score of 3 (pure-
suspected). These are the 30 populations (now all confirmed to be pure) 
referenced throughout the SSA report, the 5-year status review, the 
proposed rule, and this final rule.
    (7) Comment: One commenter stated that protection of Apache trout 
habitat in the West Fork of the Black River from exotic trout has not 
been accomplished as promised by the AZGFD and as required by the 
Central Arizona Project (CAP) settlement agreement. They indicated 
doubt that this protection would be accomplished by a conservation 
management plan.
    Our response: The 2008 Reinitiated Biological Opinion on 
Transportation and Delivery of Central Arizona Project Water to the 
Gila River Basin in Arizona and New Mexico and its Potential to 
Introduce and Spread Nonindigenous Aquatic Species (USFWS 2008, entire) 
includes a list of barriers to be constructed by U.S. Bureau of 
Reclamation (Reclamation) and states: ``Reclamation will construct a 
single fish barrier at these sites, of a design similar to those 
completed on Aravaipa, Sonoita, or Fossil Creeks. Siting and design 
will be subject to agreement between Reclamation and the Service, with 
appropriate review and input from AZGFD, the landowner, and experts on 
southwestern fishes, hydrology, and nonindigenous species invasions. 
Reclamation will maintain the barriers in good operating condition for 
the expected 100-year life of CAP. Management actions upstream of these 
barriers (e.g., stream renovation, species repatriation) will be the 
responsibility of

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the Service or AZGFD but may be funded through the existing Fund 
Transfer Program. Reclamation or its designate will monitor fish 
populations upstream of each constructed barrier for a period of five 
years following construction, unless such monitoring is redundant to 
that conducted by other agencies. Monitoring is intended to evaluate 
the success of the barriers in preventing invasions of nonindigenous 
fishes.''
    AZGFD is not required by the referenced agreement to eradicate 
invasive fish from West Fork Black River, but has been working with 
recovery partners to do so. They have been working with White Mountain 
Apache Tribe (WMAT) Game and Fish Department and the Service on 
intensive mechanical removal of brook trout in the West Fork Black 
River (upper) and Thompson Creek (upper) recovery population areas, and 
much progress has been made to eradicate them since 2021. These three 
recovery partners proposed chemical renovation of this system during 
2022, but they changed approaches due to public concerns raised during 
meetings about the project. Brook trout are much less abundant in the 
West Fork Black River (upper) recovery area and have been eradicated 
from the Thompson Creek (upper) population area, following several 
years of intensive mechanical removal efforts (2021-present).
    (8) Comment: Two commenters expressed concern over the 
effectiveness of protective barriers in keeping Apache trout 
populations free of nonnative trout. One commenter stated that all 
protective barriers would eventually be breached by exotic trout, and 
the other commenter stated that most Apache trout populations are 
isolated above protective barriers and are all at risk of invasion by 
invasive trout.
    Our response: In the SSA report we discuss how fish passage 
barriers have long been used as a conservation tool to protect Apache 
trout populations from invading nonnative fishes that occur and are 
naturalized from historical stocking practices (Robinson et al. 2004, 
entire; Avenetti et al. 2006, entire). A short-term evaluation of 
effectiveness of barriers protecting Apache trout populations found 
that only 1 of 1,436 salmonids marked downstream were collected 
upstream of the evaluated barriers over a 3-year period. Despite short-
term effectiveness, long-term evaluation was needed (Avenetti et al. 
2006, entire). Maintenance on barriers is commonly conducted by 
managers when effectiveness is questionable due to physical integrity 
or flow patterns, when channel migration compromises structural 
integrity, or for other reasons.
    In addition, barrier design has sometimes been inadequate. Large 
trout have been observed jumping step pools associated with a 1-meter 
(m) barrier on Fish Creek during high flows, suggesting passage was 
likely at high flows and that the design was inadequate (Avenetti et 
al. 2006, pp. 214-215). Recent barrier assessment included an engineer 
review and design modification suggestions that have informed barrier 
modification and maintenance, and recent barriers have been designed to 
withstand higher flows to ensure protection of Apache trout populations 
above those barriers (AZGFD and USFWS 2015, entire). The SSA report 
shows that 19 of 30 pure populations are free of nonnative trout. 
However, considering recent apparent eradications in Aspen (pending) 
and Bear Wallow (confirmed) creeks, 21 populations are now free of 
nonnative trout. Conservation barriers have been critical to recovery 
of Apache trout and other native trout recovery efforts.
    Brown trout were eradicated from Crooked Creek in 2015 after 13 
years of mechanical removal effort. Although the barrier protecting 
that population has not been replaced or modified since, the Apache 
trout population above that site has remained free of brown trout and 
their abundance has increased 379 percent: adult Apache trout abundance 
was estimated at 301 adults in 2016 and 1,444 adults in 2023. 
Similarly, abundance of Apache trout in Paradise Creek increased from 
an estimated 11 adults in 2018 to 164 adults in 2023 concomitant with 
brown trout eradication efforts, and this population will be augmented 
with additional Apache trout from Deep Creek to address genetic 
concerns due to low population size around 2018. Finally, abundance of 
Apache trout in Bear Wallow Creek increased from an estimated 384 
adults in 2020 to 1,542 adults in 2023 following nonnative trout 
eradication. It is impossible to overstate the importance of 
conservation barriers in nonnative trout management within the context 
of native trout recovery efforts in the West. Recovery partners have 
demonstrated over the last two decades that they understand how to 
build and maintain durable conservation barriers and address nonnative 
trout invasions when they occur.
    (9) Comment: One commenter stated that, in general, current land 
management plans being implemented by the USFS are generally vague and 
are not enforceable. They stated that ``desirable conditions,'' as 
outlined in Apache-Sitgreaves National Forests (ASNF) Land Management 
Plan are too broad and may not occur within timeframes beneficial to 
Apache trout. They identified the Black River Watershed Restoration 
Project as an example of how ongoing incompatible land uses (i.e., 
cattle grazing) have prevented streams from being restored. The 
commenter also stated that the conservation management plan described 
in our proposed rule is not enforceable and will open Apache trout 
stream habitat to further degradation if the species is delisted.
    Our response: As discussed in this final rule in the Recovery 
Criteria section, although the CMP is a voluntary agreement, we 
anticipate the plan will be implemented into the foreseeable future. 
Signatories of the CMP all have pre-existing legal authority for land 
management and wildlife management across the entire range of the 
Apache trout. Furthermore, signatories to the plan have more than a 40-
year track record of active, effective, and continuous voluntary Apache 
trout conservation work demonstrating an enduring commitment to the 
conservation of this species. The Apache Trout Recovery Plan and the 
CMP (USFWS 2009, entire; Apache Trout Cooperative Management Plan 
Workgroup 2021, entire) describe ways to enhance or restore stream and 
riparian habitats. Apache trout recovery partners (WMAT, AZGFD, USFWS, 
USFS, and Trout Unlimited) indicated their commitment to ensure the 
long-term persistence of Apache trout, restore and maintain quality 
instream habitats, ensure that land management is compatible with 
functioning watershed conditions, and provide and enhance sportfishing 
opportunities for Apache trout.
    The SSA report analysis of 37 distinct threat factors identified 
grazing management as the 14th most important factor affecting the 
future condition of Apache trout. Additionally, as discussed above in 
comment response (2), there are few active livestock grazing allotments 
associated with Apache trout recovery streams and the USFS engages in 
active management to remove feral horses and stray cattle where they 
occur outside of authorized areas. The actions being undertaken to date 
to address degradation to habitat due to grazing have not impeded the 
species from achieving recovery. There are Apache trout habitat areas 
where habitat quality has been degraded by legacy grazing, especially 
in sensitive wet meadow habitats, and much of that area has already 
been protected with fencing exclosures.

[[Page 72744]]

    Projects for new and rebuilt fencing exclosures of sensitive 
habitats and riparian plantings are planned on the Apache-Sitgreaves 
National Forests and Tribal lands. For example, Apache trout recovery 
partners are working cooperatively on projects to address degraded 
habitats with ungulate exclosure areas, riparian plantings, and 
instream habitat restoration projects along Burro, Centerfire, 
Hayground, and Thompson creeks, West Fork Black River, and South Fork 
Little Colorado River on the Apache Sitgreaves National Forests. 
Similar projects have already begun along Flash and Boggy/Lofer creeks 
on Tribal land. National Environmental Policy Act review for several of 
these beneficial projects fall under the umbrella of the Black River 
Watershed Restoration Project which describes many tools for improving 
watershed condition in the project area and are consistent with the 
objectives of the Apache-Sitgreaves National Forests Land Management 
Plan.

Background

    A thorough review of the biological information on the Apache trout 
including taxonomy, life history, ecology, and conservation activities, 
as well as threats facing the species or its habitat is presented in 
our SSA report (USFWS 2022a, entire) and the revised recovery plan for 
Apache trout (USFWS 2009, entire), which are available at https://www.regulations.gov under Docket No. FWS-R2-ES-2022-0115. A summary of 
that information is presented here.
    The Apache trout is a salmonid species endemic to the White 
Mountains region of east-central Arizona. The species is currently 
found in the White River, Black River, and the Little Colorado River 
drainages in the White Mountains of east-central Arizona, although the 
historical distribution is not known with certainty. Apache trout 
occupies headwater streams upstream of natural and conservation 
barriers, which likely reflects a truncated distribution from 
historical distributions due to nonnative trout, habitat alterations, 
and other factors (USFWS 2009, pp. 1, 6-16). Distinguishing 
characteristics of Apache trout include a fusiform (spindle-shaped) 
body and large dorsal fin, with spots on the body pronounced and often 
uniformly spaced both above and below the lateral line. Spots are 
circular in outline, are medium-sized, and appear slightly smaller than 
most interior subspecies of cutthroat trout (Oncorhynchus clarkii) but 
more like typical cutthroat trout than Gila trout (O. gilae) (Miller 
1972, pp. 410-411). Yellow or yellow-olive colors predominate, with 
tints of purple and pink observable on live specimens. Two black spots 
are located horizontally on the eye before and aft of the pupil, 
creating the image of a black band through the eye. A red or pink 
lateral band is usually absent (Miller 1972, p. 414). Dorsal, pelvic, 
and anal fins have conspicuous cream or yellowish tips. Like most trout 
occupying small headwater streams, the Apache trout has been described 
as an opportunistic feeder, primarily feeding on various species of 
insects such as caddisflies (Trichoptera), mayflies (Ephemeroptera), 
stoneflies (Plecoptera), and beetles (Coleoptera) (Harper 1978, p. 
108).

Recovery Criteria

    Section 4(f) of the Act directs us to develop and implement 
recovery plans for the conservation and survival of endangered and 
threatened species unless we determine that such a plan will not 
promote the conservation of the species. Under section 4(f)(1)(B)(ii), 
recovery plans must, to the maximum extent practicable, include 
objective, measurable criteria which, when met, would result in a 
determination, in accordance with the provisions of section 4 of the 
Act, that the species be removed from the Lists of Endangered and 
Threatened Wildlife and Plants.
    Recovery plans provide a roadmap for us and our partners on methods 
of enhancing conservation and minimizing threats to listed species, as 
well as measurable criteria against which to evaluate progress towards 
recovery and assess the species' likely future condition. However, they 
are not regulatory documents and do not substitute for the 
determinations and promulgation of regulations required under section 
4(a)(1) of the Act. A decision to revise the status of a species or to 
delist a species is ultimately based on an analysis of the best 
scientific and commercial data available to determine whether a species 
is no longer an endangered species or a threatened species, regardless 
of whether that information differs from the recovery plan.
    There are many paths to accomplishing recovery of a species, and 
recovery may be achieved without all of the criteria in a recovery plan 
being fully met. For example, one or more criteria may be exceeded 
while other criteria may not yet be accomplished. In that instance, we 
may determine that the threats are minimized sufficiently, and that the 
species is robust enough that it no longer meets the Act's definition 
of an endangered species or a threatened species. In other cases, we 
may discover new recovery opportunities after having finalized the 
recovery plan. Parties seeking to conserve the species may use these 
opportunities instead of methods identified in the recovery plan. 
Likewise, we may learn new information about the species after we 
finalize the recovery plan. The new information may change the extent 
to which existing criteria are appropriate for identifying recovery of 
the species. The recovery of a species is a dynamic process requiring 
adaptive management that may, or may not, follow all of the guidance 
provided in a recovery plan.
    The Apache trout recovery plan identified two major areas of focus 
to achieve the long-term survival and viability of the species: 
protection of Apache trout habitat from various watershed alteration 
activities (e.g., forestry, livestock grazing, reservoir construction, 
agriculture, road construction, and mining) and protection from 
introduction of nonnative trout species that have resulted in 
hybridization, competition, and predation (USFWS 2009, p. v). To 
achieve recovery, the recovery plan identified criteria that assist in 
determining whether the Apache trout has recovered to the point that 
the protections afforded by the Act are no longer needed. These 
criteria are:
    (1) Habitat sufficient to provide for all life functions at all 
life stages of 30 self-sustaining, discrete populations of pure Apache 
trout has been established and protected through plans and agreements 
with responsible land and resource management entities. These plans 
will address and serve to remedy current and future threats to Apache 
trout habitat.
    (2) Thirty discrete populations of genetically pure Apache trout 
have been established and determined to be self-sustaining. A 
population will be considered self-sustaining by the presence of 
multiple age classes and evidence of periodic natural reproduction. A 
population will be considered established when it is capable of 
persisting under the range of variation in habitat conditions that 
occur in the restoration stream.
    (3) Appropriate angling regulations are in place to protect Apache 
trout populations while complying with Federal, State, and Tribal 
regulatory processes.
    (4) Agreements are in place between the Service, the AZGFD, and the 
WMAT to monitor, prevent, and control disease and/or causative agents, 
parasites, and pathogens that may threaten Apache trout.

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Recovery Plan Implementation

    The following discussion summarizes the recovery criteria and 
information on recovery actions that have been implemented under each 
delisting criterion.
    Delisting Criterion 1: Habitat sufficient to provide for all life 
functions at all life stages of 30 self-sustaining, discrete 
populations of pure Apache trout has been established and protected 
through plans and agreements with responsible land and resource 
management entities. This criterion has been met.
    Since the time of listing, the Service, in collaboration with WMAT, 
AZGFD, the USFS, and Trout Unlimited, have worked to maintain and 
restore riparian habitats where the Apache trout occurs. Multiple age 
classes are represented across the populations, which are indicative of 
healthy recruitment and stable populations from year to year. Although 
the average abundance of adults is fewer than 500 within most 
populations, the diversity of age classes suggests healthy survival and 
recruitment rates. Furthermore, adult individuals make up a significant 
share of the overall population, which is indicative that many fry and 
juveniles are able to survive to adulthood without the need for 
restocking from adjacent populations or hatcheries.
    The habitat of Apache trout is managed, and land-use impacts on the 
species are reduced through environmental review of proposed projects. 
For example, the ASNF Land Management Plan incorporates desired 
conditions for aquatic habitats to contribute to the recovery of 
federally listed species and to provide self-sustaining populations of 
native species (ASNF 2015, pp. 16-26). Projects on ASNF lands also 
require National Environmental Policy Act review. WMAT also has land 
management plans to protect Apache trout populations. Alteration of 
logging practices, road closure and removal, and ungulate exclusion 
through fencing or retiring allotments have all been used to manage 
Apache trout habitat on the ANSFs and Fort Apache Indian Reservation 
(Robinson et al. 2004, p. 1; USFWS 2009, pp. 23-29).
    The WMAT, AZGFD, ASNF, USFWS, and Trout Unlimited all signed the 
2021 Apache Trout Cooperative Management Plan that has no expiration 
date and details how each agency will use their management authorities 
to conserve, protect, and manage Apache trout populations and habitat 
into the future. WMAT has sovereign authority to regulate fishing on 
the Fort Apache Indian Reservation which comprises 76 percent of Apache 
trout habitat. WMAT laws and regulations instituted land and stream 
closures prohibiting sportfishing of relict populations long before the 
Apache trout received protection under the Endangered Species Act. WMAT 
continues to prohibit sportfishing of recovery populations, and this 
policy is not expected to change. Additionally, the AZGFD provides for 
the continued protection and conservation of the Apache trout in the 
Arizona Wildlife Conservation Strategy (AZGFD 2022, entire).
    Delisting Criterion 2: Thirty discrete populations of genetically 
pure Apache trout have been established and determined to be self-
sustaining. This criterion has been met.
    Compared to the time of listing when we identified 14 genetically 
pure populations, currently, the Apache trout consists of 30 
genetically pure populations. The one population that was described as 
``pure-suspected'' in the SSA report and proposed rule has been since 
analyzed and was found to be genetically pure (Mussmann 2024, pers. 
comm). These populations are comprised of both relict and replicate 
populations. A relict population of Apache trout is one that was 
originally discovered in a stream within the historical range of the 
species and is the species' original genetic stock. A replicate 
population of Apache trout is one that was established using 
individuals from a relict population or another replicate population 
that represents a relict genetic lineage. Replicate populations are 
usually established within the historical range of the species, 
including both streams that were originally unoccupied by Apache trout 
and streams where Apache trout have been extirpated. The relict 
populations have remained pure and are self-sustaining without the need 
for restocking since their discovery (Leon 2022, pers. comm.).
    Following the initial introduction of 100 to 200 individuals, most 
of the replicate populations did not require additional introduction of 
individuals (USFWS 2022b, p. 58). However, periodic introductions of 
additional individuals from the same donor streams have been made in 
subsequent years in several populations to improve genetic diversity 
within replicated populations and to reduce impacts to donor streams 
from large, one-time transfers. Replicate populations were established 
as early as 1967 and as late as 2008.
    In order to ensure that genetically pure populations of Apache 
trout are protected, conservation barriers that prohibit nonnative 
trout species from accessing upstream portions of occupied Apache trout 
habitat have been and will continue to be constructed and maintained 
per the CMP. The conservation barriers prevent nonnative trout from 
hybridizing with, competing with, and preying on Apache trout.
    Delisting Criterion 3: Appropriate angling regulations are in place 
to protect Apache trout populations while complying with Federal, 
State, and Tribal regulatory processes. This criterion has been met.
    Apache trout recovery streams on Tribal lands have not and will not 
be opened for angling in the future according to longstanding Tribal 
policy. Twenty-five of the 30 pure populations of Apache trout are 
located in whole (22) or in part (3) on Tribal lands accounting for 
approximately 76 percent of all occupied Apache trout recovery habitat. 
Apache trout streams on national forest lands are protected with 
fishing closures when populations are small and vulnerable, and with 
catch-and-release regulations in larger populations where harvest could 
still negatively impact the population. To generate public support for 
recovery of the species, AZGFD does provide put-and-take opportunities 
for Apache trout in Silver Creek, East Fork Black River, and West Fork 
Little Colorado River. WMAT provides similar opportunities in the North 
Fork White River, lower East Fork White River, Cibeque Creek, lower 
Paradise Creek, and lower Diamond Creek. Apache trout fisheries are 
also established in some lakes (e.g., Big Bear, Hurricane, Christmas 
Tree, Earl Park) to afford the public opportunities to harvest Apache 
trout, which also has the benefit of raising public awareness for the 
species.
    Delisting Criterion 4: Agreements are in place between the Service, 
AZGFD, and WMAT to monitor, prevent, and control disease and/or 
causative agents, parasites, and pathogens that may affect Apache 
trout. This criterion has been met.
    By December 2021, the Service, AZGFD, USFS, WMAT, and Trout 
Unlimited signed the CMP for Apache trout. The goal of the CMP is to 
ensure the long-term persistence of the Apache trout by monitoring and 
maintaining existing populations, establishing new populations, 
restoring and maintaining existing habitats, and conducting disease, 
parasite, and pathogen prevention and monitoring activities. Although 
the CMP is a voluntary agreement among the cooperating agencies, it is 
reasonable to conclude the plan will be implemented into the future for 
multiple reasons.

[[Page 72746]]

    First, each of the cooperating agencies have established a long 
record of engagement in conservation actions for the Apache trout. Many 
of the management activities, such as the construction of conservation 
barriers, have been ongoing since at least the 1990s (USFWS 2022b, pp. 
70-73). Second, implementation of the CMP is already underway. The 
recovery partners are constructing and maintaining conservation 
barriers, removing invasive species, planning for restocking Apache 
trout as needed, and repairing and restoring habitats. Third, the 
conservation mission and authorities of these agencies authorize this 
work even after the species is delisted. Once the Apache trout is 
delisted the PDM plan will be initiated and will be adhered to by the 
CMP signatories and other recovery partners for at least 10 years 
(Dauwalter et al. 2024, entire). Specifically, the PDM plan prescribes 
for monitoring of Apache trout populations to ensure that the number of 
fish in populations remains stable and prescribes for ongoing 
assessments of conservation barrier effectiveness in protecting Apache 
trout from nonnative trout species. Fourth, there is a practical reason 
to anticipate implementation of the CMP into the future: the plan's 
actions are technically not complicated to implement, and costs are 
relatively low. We also have confidence that the actions called for in 
the CMP will be effective in the future because they have already 
proven to be effective as evidenced by the information collected from 
recent habitat actions and associated monitoring (USFWS 2022b, entire). 
Lastly, if the CMP is not adhered to by the cooperating agencies or an 
evaluation by the Service suggests the habitat and population numbers 
are declining, the Service would evaluate the need to again add the 
species to the List (i.e., ``relist'' the species) under the Act. Taken 
together, it is therefore reasonable to conclude that the CMP will be 
implemented as anticipated, and that the long-term recovery of Apache 
trout will be maintained and monitored adequately, thus meeting the 
conditions of this criterion.

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and the implementing 
regulations in title 50 of the Code of Federal Regulations set forth 
the procedures for determining whether a species is an endangered 
species or a threatened species, issuing protective regulations for 
threatened species, and designating critical habitat for endangered 
species. On April 5, 2024, jointly with the National Marine Fisheries 
Service, the Service issued a final rule that revised the regulations 
in 50 CFR part 424 regarding how we add, remove, and reclassify 
endangered and threatened species and what criteria we apply when 
designating listed species' critical habitat (89 FR 23919). This final 
rule is now in effect and is incorporated into the current regulations. 
Our analysis for this decision applied our current regulations. Given 
that we proposed delisting this species under our prior regulations 
(revised in 2019), we have also undertaken an analysis of whether the 
decision would be different if we had continued to apply the 2019 
regulations and we concluded that the decision would be the same. The 
analyses under both the regulations currently in effect and the 2019 
regulations are available on https://www.regulations.gov.
    The Act defines an ``endangered species'' as a species that is in 
danger of extinction throughout all or a significant portion of its 
range, and a ``threatened species'' as a species that is likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range. The Act requires that we 
determine whether any species is an endangered species or a threatened 
species because of any of the following factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects. The determination to delist a 
species must be based on an analysis of the same five factors.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the species' expected response and 
the effects of the threats--in light of those actions and conditions 
that will ameliorate the threats--on an individual, population, and 
species level. We evaluate each threat and its expected effects on the 
species, then analyze the cumulative effect of all of the threats on 
the species as a whole. We also consider the cumulative effect of the 
threats in light of those actions and conditions that will have 
positive effects on the species--such as any existing regulatory 
mechanisms or conservation efforts. The Secretary determines whether 
the species meets the definition of an ``endangered species'' or a 
``threatened species'' only after conducting this cumulative analysis 
and describing the expected effect on the species.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis which is 
further described in the 2009 Memorandum Opinion on the foreseeable 
future from the Department of the Interior, Office of the Solicitor (M-
37021, January 16, 2009; ``M-Opinion,'' available online at https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf). 
The foreseeable future extends as far into the future as we can make 
reasonably reliable predictions about the threats to the species and 
the species' responses to those threats. We need not identify the 
foreseeable future in terms of a specific period of time. We will 
describe the foreseeable future on a case-by-case basis, using the best 
available data and taking into account considerations such as the 
species' life-history characteristics, threat-projection timeframes, 
and environmental variability. In other words, the foreseeable future 
is the period of time over which we can make reasonably reliable 
predictions. ``Reliable'' does not mean ``certain''; it means 
sufficient to

[[Page 72747]]

provide a reasonable degree of confidence in the prediction, in light 
of the conservation purposes of the Act.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
stressors to the species. The SSA report does not represent our 
decision on whether the species should be delisted. However, it does 
provide the scientific basis that informs our regulatory decisions, 
which involve the further application of standards within the Act and 
its implementing regulations and policies.
    To assess the Apache trout's viability, we used the three 
conservation biology principles of resiliency, representation, and 
redundancy (Smith et al. 2018, pp. 306-310). Briefly, resiliency is the 
ability of the species to withstand environmental and demographic 
stochasticity (for example, wet or dry, warm or cold years), redundancy 
is the ability of the species to withstand catastrophic events (for 
example, droughts, large pollution events), and representation is the 
ability of the species to adapt to both near-term and long-term changes 
in its physical and biological environment (for example, climate 
conditions, pathogen). In general, species viability will increase with 
increases in resiliency, redundancy, and representation (Smith et al. 
2018, p. 306). Using these principles, we identified the species' 
ecological requirements for survival and reproduction at the 
individual, population, and species levels, and described the 
beneficial and risk factors influencing the species' viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated individual species' life-history 
needs. The next stage involved an assessment of the historical and 
current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. Throughout all of these 
stages, we used the best available information to characterize 
viability as the ability of a species to sustain populations in the 
wild over time, which we then used to inform our regulatory decision.
    The following is a summary of the key results and conclusions from 
the SSA report; the full SSA report can be found on the Service website 
at https://ecos.fws.gov/ecp/species/3532 and at https://www.regulations.gov under Docket No. FWS-R2-ES-2022-0115.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of the 
Apache trout and its resources, and the threats that influence the 
species' current and future condition, in order to assess the species' 
overall viability and the risks to that viability. In addition, the SSA 
report documents our comprehensive biological status review for the 
species, including an assessment of the potential threats to the 
species. The following is a summary of this status review and the best 
available information gathered since that time that have informed this 
decision.
    The primary threats affecting the Apache trout are the invasion of 
nonnative trout species into Apache trout habitat and the effects of 
climate change, which are projected to result in more wildfire and 
debris runoff in streams. Introgression of nonnative trout species into 
Apache trout habitat has resulted in hybridization of certain 
populations. Additionally, nonnative trout species compete with the 
Apache trout, and certain species have been known to prey on the Apache 
trout. Wildfires in the region can result in ash and debris flow, 
creating unsuitable conditions for the Apache trout and possibly 
resulting in fatalities and extirpation of populations. To address 
these major threats, management actions, including construction of 
conservation barriers, as well as restocking and restoring habitats, 
have been implemented.

Nonnative Species

    Nonnative species, especially nonnative salmonids, remain one of 
the largest threats to the Apache trout (Rinne 1996, p. 152). Over 61 
million nonnative sport fishes have been stocked into lakes in the 
Little Colorado and Black River drainages since the 1930s (Rinne and 
Janisch 1995, p. 398). Over 8 million nonnative sport fishes were 
introduced directly into the Little Colorado and Black rivers and their 
tributaries since the 1930s, and many of these were nonnative salmonids 
(Rinne and Janisch 1995, p. 398). Recent stocking practices have been 
altered to reduce interactions with, and risks to, native species, such 
as using triploid (sterile) rainbow trout for stocking into open water 
systems (EcoPlan Associates 2011, p. 21). However, threats remain due 
to acclimated nonnative populations from historical stockings.
    As discussed below, hybridization with rainbow trout and cutthroat 
trout can lead to functional extirpation of Apache trout populations. 
Competition with and predation by brown trout and brook trout are also 
of high concern. While no published studies have documented competition 
and predation impacts on Apache trout by nonnative salmonids such as 
brown trout and brook trout, it is generally accepted that the negative 
interaction has led to reduction or extirpation of some populations 
(Rinne 1996, p. 152). Appendix C of the SSA report analyzes the 
negative effect of nonnative trout presence on occupancy of juvenile 
Apache trout at the site scale in fish surveys (USFWS 2022a, p. 134-
137).

Genetic Factors (Population)

    Discussed below are the three genetic factors that pose a risk to 
the viability of Apache trout populations: hybridization, inbreeding, 
and low genetic variability.
Hybridization
    Hybridization can introduce traits that are maladaptive, disrupt 
adaptive gene complexes, or result in outbreeding depression (Hedrick 
2000, entire). Hybridization can also lead to the loss of species-
specific alleles, and hybridization with Pacific trout species has long 
been recognized as a threat to the viability of native trout species 
(or subspecies) (Behnke 1992, p. 54). This has resulted in arguments 
that only genetically pure populations should be considered a part of 
the species or subspecies (Allendorf et al. 2004, p. 1212).
    A long history of nonnative trout stocking in Arizona has led to 
hybridization between Apache trout and rainbow trout, even to the 
extent of genetic extirpation, and it is one of the main reasons for 
the historical decline of Apache trout (Rinne and Minckley 1985, pp. 
285, 288-291; Carmichael et al. 1993, pp. 122, 128; Rinne 1996, pp. 
150-152). The major threat of hybridization is the reason the 2009 
revised recovery plan lists as an objective the establishment and/or 
maintenance of 30 self-sustaining, discrete populations of genetically 
pure Apache trout within its historical range (USFWS 2009, pp. vi, vii, 
5, 22). That same objective has largely been in place since the first 
recovery plan was developed for the species in 1979 (USFWS 1979, p. 
15). A comprehensive assessment of the genetic purity of naturally 
reproducing Apache trout populations in 1993 showed only 11 of 31 
streams were deemed to be generically pure (Carmichael et al. 1993,

[[Page 72748]]

p. 128). At the time the 2009 revised recovery plan was completed, 28 
populations of genetically pure Apache trout were extant (USFWS 2009, 
p. 2). The proposed delisting rule for Apache trout indicated that 
there were 29 genetically pure populations (88 FR 54548; August 11, 
2023); one population described as ``pure-suspected'' in the proposed 
delisting rule has since been confirmed to be genetically pure. 
Currently, the Apache trout consists of 30 genetically pure 
populations.
Inbreeding and Low Genetic Diversity
    Small populations are more likely to exhibit inbreeding and low 
genetic diversity. Inbreeding often results in inbreeding depression 
and expression of recessive and deleterious alleles (Wang et al. 2002, 
p. 308). Cutthroat trout are an example of inland trout in North 
America where inbreeding has been documented for some small, isolated 
populations (Metcalf et al. 2008, p. 152; Carim et al. 2016, pp. 1368-
1372). Low genetic diversity limits the ability of populations to adapt 
to changing and novel environments (Allendorf and Ryman 2002, pp. 62-
63).
    The one study of genetic diversity in Apache trout showed strong 
distinction among three genetic lineages (Soldier, Ord, and East Fork 
White River lineages) represented by the nine populations studied, but 
genetic diversity was low within populations (Wares et al. 2004, pp. 
1896-1897). Low genetic diversity within populations suggests that they 
were founded with a small number of individuals. Replicate populations 
of Apache trout have often been established with a few hundred 
individuals, with an unknown subset successfully reproducing. No 
studies have evaluated inbreeding in Apache trout populations, or how 
genetic management (e.g., genetic rescue) may benefit Apache trout 
populations, and these topics remain of management interest (Wang et 
al. 2002, pp. 308, 313-315; Whiteley et al. 2015, pp. 42-48; Robinson 
et al. 2017, pp. 4418-4419, 4430).

Climate Change, Wildfire, Stream Conditions

    The climate has changed when compared to historical records, and it 
is projected to continue to change due to increases in atmospheric 
carbon dioxide and other greenhouse gasses (U.S. Global Change Research 
Program 2017, pp. 10-11). The American Southwest has the hottest and 
driest climate in the United States. The U.S. Fourth National Climate 
Assessment suggests that warming temperatures will lead to decreasing 
snowpack, increasing frequency and severity of droughts, and increasing 
frequency and severity of wildfires, and these in turn will result in 
warmer water temperatures, reduced streamflows (especially baseflows), 
and increased risk of fire-related impacts to aquatic ecosystems 
(Gonzales et al. 2018, pp. 1133-1136; Overpeck and Bonar 2021, p. 139). 
In fact, the current drought in the western United States is one of the 
worst in the last 1,200 years and is exacerbated by climate warming 
(Williams et al. 2020, p. 317). Climate warming will make droughts 
longer, more severe, and more widespread in the future.
    An eight-fold increase in the amount of land burned at high 
severity during recent wildfires, including in the southwestern United 
States, has been observed and it is likely that warmer and drier fire 
seasons in the future will continue to contribute to high-severity 
wildfires where fuels remain abundant (Parks and Abatzoglou 2021, p. 
6). Wildfires have increased in frequency and severity in Arizona and 
New Mexico primarily due to changes in climate but also because of 
increased fuel loads (Mueller et al. 2020, p. 1; Parks and Abatzoglou 
2021, pp. 5-7), including within the historical range of the Apache 
trout (Dauwalter et al. 2017a, entire). Larger, more frequent, and more 
severe wildfires accompanying a changing climate together may drive 
conversions in vegetation type from forest to shrub or grassland 
because of higher tree mortality, limited seed dispersal in larger burn 
patches, soil damage that reduces seedling establishment, and a 
changing climate that reduces seedling survival--all of which combine 
to inhibit forest regeneration (Keeley et al. 2019, p. 775; Coop et al. 
2020, p. 670). Wildfires can result in ash flows that create unsuitable 
water quality conditions for salmonids, and high-intensity fires in 
steep watersheds are likely to result in channel-reorganizing debris 
flows (Gresswell 1999, pp. 210-211; Cannon et al. 2010, p. 128). 
Approximately 30 percent of forests in the Southwest are projected to 
have an elevated risk of conversion to shrubland and grassland because 
of increased fire severity due to climate change (Parks et al. 2019, p. 
9). Conifer reduction in the White Mountains could reduce stream 
shading important for maintaining suitable stream temperatures for 
Apache trout (Baker and Bonar 2019, pp. 862-864).
    In the absence of existing peer-reviewed science on the effects of 
climate change on the Apache trout itself, we applied the vulnerability 
assessment approach that was used to evaluate wildfire and temperature 
warming vulnerability in Gila trout streams and applied it to Apache 
trout populations (USFWS 2022a, pp. 121-130). The analysis suggests 
that streams such as West Fork Little Colorado River have a high risk 
of crown fire (wildfire spreading at the canopy level) and subsequent 
debris flows. Other streams in the Wallow Fire perimeter have a lower 
risk of future wildfires due to reduced fuel loads.
    To evaluate stream temperature risk due to climate warming, we 
first evaluated Apache trout occupancy across all habitat patches and 
found that 95 percent of all occupied patches occurred in reaches at or 
below 16.5 degrees Celsius ([deg]C) (61.7 degrees Fahrenheit ([deg]F)) 
mean July water temperatures. Then all streams were modeled to contain 
reaches where mean July water temperatures were less than or equal to 
16.5 [deg]C (61.7 [deg]F), a conservative temperature threshold, based 
on temperature projections for the 2080s from an ensemble global 
climate model for the A1B emissions scenario (i.e., middle-of-the-road 
scenario). Big Bonito Creek, Fish Creek, and Boggy/Lofer Creeks 
contained the largest amount of habitat with mean July temperatures 
less than 16.5 [deg]C (61.7 [deg]F) in the 2080s. The East Fork Little 
Colorado River, Snake Creek, Rock Creek, Rudd Creek, and South Fork 
Little Colorado River had the lowest percent of habitat with mean July 
temperatures less than or equal to 16.5 [deg]C (61.7 [deg]F) in the 
2080s.
    Most Apache trout habitat patches are not currently limited by warm 
stream temperatures because the habitat designated for species recovery 
is upstream of fish passage barriers (Avenetti et al. 2006, p. 213; 
USFWS 2009, p. 19; USFWS 2022b, pp. 118-127). Based on our analysis, 
these habitat patches are far enough upstream to also not be limited by 
warm stream temperatures into the 2080s. Some streams may even be 
currently limited by cold temperatures for juvenile Apache trout, and 
these areas may in fact benefit from warmer stream temperatures at 
least up until the 2080s.

Cumulative Impacts

    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have not 
only analyzed individual effects on the species, but we have also 
analyzed their potential cumulative effects. We incorporate the 
cumulative effects into our SSA analysis when we characterize the 
current and future conditions of the species. To assess the current and 
future

[[Page 72749]]

conditions of the species, we undertake an iterative analysis that 
encompasses and incorporates the threats individually and then 
accumulates and evaluates the effects of all the factors that may be 
influencing the species, including threats and conservation efforts. 
Because the SSA framework considers not just the presence of the 
factors, but to what degree they collectively influence risk to the 
entire species, our assessment integrates the cumulative effects of the 
factors and replaces a standalone cumulative effects analysis.

Conservation Efforts and Regulatory Mechanisms

    Several conservation actions are routinely undertaken to protect, 
restore, and re-establish Apache trout populations across the species' 
historical range and, in one case, outside of the historical range. 
Discussed below are the major past and ongoing conservation efforts for 
Apache trout, which include removal of nonnative trout species, 
reintroduction of Apache trout, habitat maintenance and restoration, 
hatchery propagation, and angling regulations. These activities are 
managed under the CMP. The CMP will remain in force until terminated by 
mutual agreement of signed parties. Any involved party may withdraw 
from this plan on 30 days' written notice to the other signatories. 
Amendments to the CMP may be proposed by any involved party and will 
become effective upon written approval by all partners.
Nonnative Trout Removal
    Removal of nonnative salmonids often occurs after conservation 
barriers are constructed and before Apache trout are reintroduced, or 
removals are done when nonnative salmonids have invaded an extant 
Apache trout population. As noted above, conservation barriers are 
artificial barriers built to separate upstream populations of Apache 
trout from downstream populations where other trout species and hybrids 
are found. These downstream populations are managed to provide 
sportfishing opportunities. Removal is commonly done using piscicides 
(chemicals that are poisonous to fish) or electrofishing. A few studies 
have documented the higher effectiveness of piscicides on removing 
nonnative salmonids from Apache trout streams, although more than one 
treatment may be required (Rinne et al. 1981, p. 78; Kitcheyan 1999, 
pp. 16-17).
    Electrofishing (often referred to as mechanical removal) is also 
used to remove nonnative fishes where piscicides have not been approved 
for use, or where populations of Apache trout are sympatric with 
nonnative trout, and it is not desirable to eliminate Apache trout 
simultaneously with nonnative trout. For example, electrofishing was 
used from 2018 to 2021, to remove over 14,670 brook trout and 3,932 
brown trout from 9 Apache trout streams, with successful eradication 
suspected in some streams that will be later confirmed with future 
electrofishing or environmental DNA surveys (Manuell and Graves 2022, 
p. 8).
    Piscicides are typically more effective at ensuring all fish are 
removed, which is important because nonnative populations can become 
reestablished if only a few individuals survive (Thompson and Rahel 
1996, pp. 336-338; Finlayson et al. 2005, p. 13; Meyer et al. 2006, p. 
858). In contrast, electrofishing removal is most effective in small 
stream systems with simple habitat (Meyer et al. 2006, p. 858). 
Environmental DNA surveys are conducted to confirm presence or absence 
of target organisms; this technique is often used in native trout 
conservation projects to help locate any remaining nonnative fish and 
target them for removal using either electrofishing or secondary 
applications of piscicides (Carim et al. 2020, pp. 488-490).
Reintroduction
    Apache trout are typically reintroduced after the habitat is 
protected by a conservation barrier and nonnative salmonids have been 
removed. Apache trout populations are usually established using fish 
from another population, although hatchery stocks have been used to 
establish populations as well. The donor stream is selected, in part, 
based on the number of fish in that population so that removing some 
does not jeopardize donor population viability; donor stream selection 
is also based on the need to replicate relict populations to enhance 
redundancy of those lineages. Planning efforts are underway to 
establish additional populations where feasible, for example in Fish 
Creek, Hayground Creek, Home Creek, and the lower West Fork-Black 
River. Historically, 100 to 200 fish have been used to establish 
populations, but there is evidence that this number of founding 
individuals has resulted in the low genetic diversity observed in some 
populations (Wares et al. 2004, pp. 1896-1897). Future populations will 
be established using larger total numbers over several years to 
maximize genetic diversity while minimizing impacts to donor 
populations (USFWS 2021, p. 13).
Habitat Management and Restoration
    Past habitat surveys and anecdotal observations identified stream 
segments in poor condition and in need of protection and restoration 
(Carmichael et al. 1995, p. 116; Robinson et al. 2004, pp. 1-3, 14-17). 
The subbasins where Apache trout are found are managed by multiple 
agencies at the Federal, State, and Tribal level. The management of the 
individual subbasins are as follows: Black River (WMAT, USFS/AZGFD), 
Bonito Creek (WMAT), East Fork White River (WMAT), North Fork White 
River (WMAT), Diamond Creek (WMAT), Little Colorado River (USFS/AZGFD), 
and Colorado River (AZGFD). Of the 30 genetically pure populations, 16 
relict and 6 replicated populations occur only on WMAT lands, 1 relict 
and 1 replicated population occur on both WMAT and USFS/AZGFD managed 
lands (Soldier Creek and upper West Fork Black River, respectively), 5 
replicated populations occur only on USFS/AZGFD managed lands, and 1 
replicated population occurs on both San Carlos Apache Tribe and USFS/
AZGFD managed lands (Bear Wallow Creek).
    The habitat of Apache trout is managed to ameliorate land-use 
impacts through environmental review of proposed projects. For example, 
WMAT has land management plans that protect Apache trout populations 
and implement habitat restoration projects. Projects occurring on or 
adjacent to Apache trout habitat include alteration of logging 
practices, road closure and removal, and ungulate exclusion through 
fencing or retiring allotments, and all have been reviewed for 
potential impacts to Apache trout habitat on the ASNF and Fort Apache 
Indian Reservation (Robinson et al. 2004, entire; USFWS 2009, p. 23).
    The Southwest Region of the USFS has the Riparian and Aquatic 
Ecosystem Strategy (Strategy; USFS 2019, entire), and restoration of 
aquatic habitat is identified through site-specific land management 
actions, such as the currently ongoing Black River Restoration Project. 
Working with partners on such actions is outlined in the Strategy (USFS 
2019, pp. 17-18).
Hatcheries
    Hatcheries have been used for Apache trout conservation and to 
establish sportfishing opportunities in lakes and streams. Apache trout 
from Williams Creek National Fish Hatchery have been used to establish 
populations including those in the West Fork Little Colorado

[[Page 72750]]

and West Fork Black rivers, but they have been most often used to 
provide sportfishing opportunities in lakes and streams on the Fort 
Apache Indian Reservation. Progeny from the Apache trout broodstock at 
Williams Creek National Fish Hatchery are also transferred annually, at 
the direction of WMAT, to be reared at Arizona's Silver Creek and Tonto 
Creek hatcheries and stocked to support sportfishing on State-managed 
lands. This broodstock is expected to be used to establish additional 
recovery populations in the future due to improvements in genetic 
fitness and representation following several years of incorporating 
wild milt (fish semen) into the broodstock program (2017-present).
Angling and Harvest Regulations
    Apache trout streams are largely protected with fishing closures 
when populations are small and vulnerable, or by catch-and-release 
regulations in larger populations where harvest could negatively impact 
the population. WMAT does not allow any fishing to occur in areas 
occupied by Apache trout recovery populations. Both WMAT and AZGFD 
provide put-and-take opportunities for Apache trout in multiple lakes 
and streams to afford the public opportunities to harvest Apache trout 
and generate public awareness and support for recovery of the species.
Emergency Contingency Plan
    Wildfire, drought, nonnative trout invasions (e.g., barrier 
failure), and disease can threaten the viability and genetic integrity 
of Apache trout populations. We and our partners will continue to track 
these threats during the monitoring described in the CMP or through 
other monitoring and reporting systems. If needed, we and our partners 
in the CMP will transport individual fish to other streams or 
hatcheries with suitable isolation facilities until they can be 
repatriated into their original or an alternate site (USFWS 2021, p. 
13).

Current Condition

Resiliency--Demographic and Habitat Factors

    Resiliency references the ability of a species or population to 
bounce back from disturbances or catastrophic events, and is often 
associated with population size, population growth rate, and habitat 
quantity (patch size) and quality (USFWS 2016, p. 6).
    Three demographic and six habitat factors were used to describe the 
current condition (status) and overall resiliency of Apache trout 
populations. These factors are commonly used to describe the health and 
integrity of native trout populations in the western United States 
(Williams et al. 2007, pp. 478-481; USFWS 2009, pp. 17-22; Dauwalter et 
al. 2017a, pp. 1-2). The three demographic factors are genetic purity, 
adult population size, and recruitment variability. The six habitat 
factors are stream length occupied, July temperature, percent of stream 
intermittency, habitat quality, nonnative trout presence, and barrier 
effectiveness.
    Hybridization can introduce traits that are maladaptive or result 
in outbreeding depression. Thus, often only genetically pure 
populations are considered to be part of a species for conservation 
purposes. Apache trout populations were classified using the results of 
the most recent genetic testing for the presence of nonnative trout 
alleles (rainbow trout and cutthroat trout) when available (Carmichael 
et al. 1993, p. 127; Carlson and Culver 2009, pp. 5-9; Weathers and 
Mussmann 2020, pp. 4-7; Weathers and Mussmann 2021, pp. 4-7). Genetic 
material (e.g., fin clips) is often collected during population 
monitoring, or it is collected during surveys targeting fish for 
genetic testing if there is evidence that barriers are compromised or 
other evidence suggests that hybridizing species (rainbow trout and 
cutthroat trout) or hybrid individuals may be present (e.g., from 
visual assessment). In the absence of genetic testing, the presence of 
hybridizing species, presence of hybrid phenotypes, or professional 
judgment based on putative barrier effectiveness were used to classify 
populations as being genetically pure or hybridized.
    Adult population size is the estimated number of adult Apache trout 
(greater than or equal to 130-mm TL) in a population in the most recent 
year of population monitoring. Before 2016, estimates of streamwide 
adult abundance were made from monitoring data collected under the 
basinwide visual estimation technique protocol (Dolloff et al. 1993, 
pp. v-17), and in a few cases, from information collected during 
general aquatic wildlife surveys (e.g., Robinson et al. 2004, pp. 3-13) 
or from electrofishing data (catch per single electrofishing pass) when 
collecting tissues for genetic analysis (such as was used in Carlson 
and Culver 2009). Since 2016, estimates of adult abundance have been 
based on an updated systematic sampling design (Dauwalter et al. 2017a, 
entire). Recruitment variability seeks to quantify the number of size 
classes present. The presence of individuals in more size (and 
therefore age) classes is indicative of more stable recruitment from 
year to year, which indicates that populations are more able to 
withstand year-to-year environmental variability (stochasticity; 
Maceina and Pereira 2007, pp. 121-123). Length frequency data from 
monitoring surveys were used to determine the number of size classes 
present.
    The length of an occupied stream, often referred to as patch size, 
was measured in kilometers using the National Hydrography Dataset 
(1:24,000 scale), and upstream and downstream extents were typically 
defined by experts as the extent of occupancy from fish survey data, 
suitable habitat, or barriers to fish passage (conservation barriers). 
Extent of occupied habitat has been shown to be positively associated 
with the probability of population persistence (e.g., viability, 
extinction probability) for western native trout (Harig et al. 2000, 
pp. 997-1000; Hilderbrand and Kershner 2000, pp. 515-518; Finlayson et 
al. 2005, p. 13), and it has been used as an indicator of persistence 
in indices of population health and as an indicator of translocation 
success (Harig and Fausch 2002, pp. 546-548; Williams et al. 2007, pp. 
479-480; Cook et al. 2010, pp. 1505-1508).
    We selected July temperature as a measurement of habitat quality 
because the Apache trout, like other salmonids, is a cold-water 
stenotherm (a species that can survive only within a narrow range of 
temperature). Under Climate Change, Wildfire, Stream Conditions, above, 
we highlight the thermal tolerance and habitat suitability values 
derived from several laboratory and field studies of Apache trout. The 
maximum mean July temperature in habitat extent occupied by each Apache 
trout population is based on modeled average July temperatures 
predicted for each 1-km stream segment in Arizona from the NorWeST 
dataset (Isaak et al. 2017, pp. 7-13). The NorWeST dataset predicts 
mean August temperatures (average of mean daily temperatures for the 
month of August) for each 1-km (0.6 mi) stream segment in the National 
Hydrography Dataset (1:100,000 scale). These predictions were adjusted 
based on an empirical relationship between mean August and mean July 
(monthly mean of mean daily temperatures) temperatures in Apache trout 
streams from data collected by USFS on ASNF.
    Intermittency percentage is the percent of occupied habitat extent 
estimated to become intermittent during severe drought years. The 
percent of stream length occupied that becomes intermittent (dry) 
during severe drought years due to low natural flows, decreasing flow 
trends in recent years, anthropogenic impacts to flow, or other

[[Page 72751]]

factors. The percentage was based on professional judgment and 
knowledge of the habitat. The southwestern United States is a naturally 
warm and dry environment with reduced surface water resources that may 
subside due to low annual precipitation (snowpack and rainfall) and 
interactions with local geology (Long et al. 2006, pp. 90-94). The 
region is currently in a megadrought that has large consequences for 
streamflows (Williams et al. 2020, p. 314), and other researchers 
highlighted the time period from 2000 to 2003 as a severe drought 
period (Hoerling and Eischeid 2007, p. 2).
    Habitat quality is the condition of riparian and instream habitat 
throughout the occupied habitat extent. Stream habitat quality was 
classified based on professional judgment at the whole stream scale or 
by segment and then computed as a weighted average (weighted by 
length).
    The presence of rainbow trout, brown trout, brook trout, or 
cutthroat trout within the habitat accessible to the Apache trout 
population (or defined habitat extent) is either confirmed or not 
present. Rainbow trout and cutthroat trout have been documented to 
hybridize with Apache trout (Carmichael et al. 1993, p. 128), and brown 
trout and brook trout compete with and prey on Apache trout, thus 
reducing the carrying capacity of habitat to support Apache trout 
(Carmichael et al. 1995, p. 114). Presence of each species is 
attributed based on survey data, angler reports, anecdotal information, 
and, in some cases, barrier effectiveness and proximity of nonnative 
species and likelihood of invasion upstream of ineffective barriers.
    Barriers were classified as functional or nonfunctional, and 
functionality was classified as known or suspected. Functionality was 
classified based on documented presence of nonnative trout above a 
barrier, documented movement of marked fish from below to above a 
barrier, known streamflow paths around or through barriers, poor 
structural integrity, or other factors influencing perceived 
functionality based on professional judgment. On some streams, more 
than one conservation barrier has been constructed to provide 
functional redundancy and security due to possible failure, as well as 
to allow management flexibility for controlling nonnative trout 
invasions or conducting nonnative trout removals (mechanical or 
chemical).

Resiliency

    The resiliency of Apache trout populations (and habitats) was 
assessed using a 4.0 grading scale and grade-point-average (GPA) 
framework. Using this framework, each Apache Trout population received 
a grade and grade point equivalents based on the current condition of 
the three demographic and six habitat factors described above. The 
condition of each factor was graded based on the results of expert 
elicitation (see USFWS 2022a, pp. 85-96 for how this grading scale was 
used to evaluate Apache trout population resiliency).
    Demographic and habitat factor data show that relict and hybridized 
Apache trout populations occur in two major river basins (the Black 
River and White River basins), replicate populations occur in all major 
basins (including one replicate population outside the species' 
historical range in the Colorado River), and unoccupied recovery 
streams occur in the Little Colorado River and Black River basins. 
Relict populations occur in five of six subbasins to which they are 
native. Hybridized populations occur in the Black River and Diamond 
Creek subbasins. As mentioned previously, of the 38 extant populations 
of Apache trout, 30 populations of Apache trout are known to be pure, 
(81.1 percent). One of eight (12.5 percent) populations has been 
confirmed as hybridized through genetic testing, whereas seven have 
been assumed to be hybridized because of known barrier failures and 
invasion of rainbow trout.
    A summary of demographic factors showed a majority of genetically 
pure Apache trout populations to have adult (greater than 130-mm [5.1 
in] TL) population sizes of between 100 and 1,000 individuals (see 
table 11 in USFWS 2022b, p. 86); one population, East Fork White River, 
was estimated to have more than 2,200 adults (see table 11 in USFWS 
2022b, p. 86). Most populations showed consistent recruitment, with 
four or five size classes (and presumably year classes) present, which 
suggests they are stable and self-sustaining populations (see figure 
18C in USFWS 2022b, p. 83).
    Habitat factors for Apache trout populations showed a wide range of 
current conditions. The extent of stream occupied by Apache trout 
populations ranged from 0.4 km (0.25 mi) to 30.1 km (18.7 mi); most 
were less than 14 km (8.7 mi). Maximum mean July temperatures in 
occupied habitat were less than or equal to 15.5 [deg]C (59.9 [deg]F) 
for relict and replicate populations, whereas unoccupied streams and 
hybrid populations had warmer maximum mean July temperatures up to 17.5 
[deg]C (63.5 [deg]F). Most populations or unoccupied streams exhibited 
little intermittency during severe drought, but two hybridized 
populations and one unoccupied stream were estimated to be more than 50 
percent intermittent (up to 95 percent). Unoccupied streams and streams 
occupied by hybrid populations had the lowest habitat quality (in part 
due to 2011 Wallow Fire), while a majority of relict and replicate 
populations inhabited high-quality habitat. Nineteen Apache trout 
populations were sympatric with brown trout, 7 with rainbow trout, and 
2 with brook trout. Thirty-six populations or unoccupied recovery 
streams currently have conservation barriers to isolate them from 
nonnative fishes downstream; 31 of these populations are protected by 
barriers that are known or suspected to be functional; 10 populations 
have a second barrier downstream for added protection across all 
population types (relict, replicate, hybrid, unoccupied).
    Overall, the current condition of the 30 genetically pure Apache 
trout populations averaged 2.89 (B average) on a 4.0 scale. Based on 
the demographic and habitat factor grade point equivalents for each 
population, Apache trout populations were more often limited by 
demographic factors than habitat factors. Adult (greater than 130-mm 
TL) population size was most frequently the limiting demographic 
factor. Unoccupied streams (e.g., Home Creek) had demographic GPAs 
equaling 0.0. East Fork White River had the highest demographic GPA 
(4.00). Likewise, presence of nonnative trout was frequently a limiting 
habitat factor. Centerfire and Stinky creeks on the Apache-Sitgreaves 
National Forests (ASNF) had the lowest habitat factor (GPA of 1.33); 
Deep Creek (WMAT) had the highest habitat factor (GPA of 3.50).

Redundancy and Representation

    Redundancy and representation and for Apache trout were evaluated 
by quantifying the presence of relict populations, and their 
replication on the landscape, as putative genetic lineages at the 
subbasin level. Redundancy was measured as the replication of relict 
lineages into new streams by subbasin. Replication of relict 
populations, and thus redundancy of purported relict subbasin lineages, 
was measured both within and outside of the native subbasin for each 
subbasin genetic lineage. The number of populations that meet certain 
persistence, abundance, and recruitment criteria can also be used to 
quantify population redundancy by subbasin or a larger basin unit 
(e.g., geographic management unit).

[[Page 72752]]

Representation was based on presence of genetically pure relict 
populations from each subbasin.
    Tracking the redundancy and representation of relict populations by 
subbasin, as subbasin lineages, is a surrogate for the assumed unique 
genetic diversity, and presumed unique adaptation potential, that is 
often found to be structured around the hierarchical nature of drainage 
basins (Vrijenhoek et al. 1985, pp. 400-402; Wares et al. 2004, pp. 
1890-1891, 1897). While such genetic structuring is evident in Apache 
trout for the nine populations (and three genetic lineages) that have 
been studied (Wares et al. 2004, pp. 1895-1896), no comprehensive 
rangewide study of genetic diversity has been conducted across all 
genetically pure populations. Accounting for relict Apache trout 
populations in this way presumably reflects the representation and 
redundancy of genetic diversity, and thus adaptive potential, of the 
species in each subbasin in which it is native.
    When quantified in this way, extant relict populations exist in 
five of six subbasins within the historical range of the Apache trout; 
only the Little Colorado River subbasin is no longer represented within 
an extant relict lineage. The East Fork White River subbasin has the 
highest level of redundancy and representation; it contains six relict 
populations still extant within the subbasin and four replicated 
populations in other subbasins that were founded with individuals from 
relict populations native to the East Fork White River subbasin. Of the 
subbasins containing relict populations, the Black River and Diamond 
Creek subbasins contain the lowest level of redundancy and 
representation, with three populations each occurring on the landscape 
(Black River: one relict and two replicates; Diamond Creek: two relicts 
and one replicate).

Future Condition

    The primary threats affecting Apache trout viability include 
invasion by nonnative trout and climate change, which encompasses 
warmer stream temperatures, more frequent and severe droughts, 
increased wildfire frequency and post-fire debris flow, reduced 
snowpack and increased rain on snow events, and more intense summer 
monsoon precipitation. A 30-year future (which equates to approximately 
six generations of Apache trout) was chosen for our future condition 
projections because within this timeframe it is likely that these 
primary threats will continue to be relevant to the species, and also 
because it is biologically reasonable to assess the species' response 
to these threats within this timeframe. Additionally, this timeframe 
allows us to reasonably forecast upcoming management activities as they 
will be implemented through the CMP.
    Continued implementation of the CMP will actively manage threats to 
Apache trout including the presence of nonnative trout and wildfire and 
post-fire debris flow. Nonnative trout impact the Apache trout in 
multiple ways including hybridization, predation, and competition. 
Wildfires primarily produce debris flows that render habitat unsuitable 
for the species. To mitigate these two threats, recovery partners will 
continue to undertake successful conservation actions such as 
construction and maintenance of conservation barriers, removal (by 
physical or chemical means) of nonnative trout species, restocking of 
Apache trout via hatchery and/or existing relict populations, 
restoration of Apache trout habitats and reduction of fuel loads to 
reduce the risk of wildfires, and fish salvages following wildfires per 
the CMP. Continued construction and maintenance of conservation 
barriers will continue to prevent hybridization of the Apache trout 
with other trout species, as well as to prevent competition with and 
predation by other fish species.
    Climate change threats that are more uncertain and difficult to 
mitigate include warming stream temperatures, more frequent and severe 
droughts, reduced snowpack with increased rain on snow events, and more 
intense summer monsoon precipitation. The future scenarios that were 
developed for Apache trout incorporate these factors in order to 
evaluate how climate variability might influence future condition for 
the species.
    While the SSA report contains a total of five scenarios, in 
determining the future condition and status of the species for this 
rulemaking we determined that only two of the five scenarios are 
plausible. Scenarios 1 and 2 in the SSA assumed that no multi-agency 
CMP would be in place after the species is delisted; however, since the 
SSA report and the scenarios were developed, the CMP has been signed 
and is currently being implemented, making these scenarios not 
plausible. Our assessment of scenarios indicated that scenario 5 is 
also not plausible given the constraints involved with securing funding 
and commitment from partners for ``greatly increased'' management of 
the species to occur (USFWS 2022a, p. 121). Given these factors, we did 
not consider scenarios 1, 2, and 5 and relied on scenarios 3 and 4 to 
inform our status determination.
    As noted above, a 30-year timeframe was chosen because it 
encompasses six generations of Apache trout and is, therefore, a 
biologically reasonable timeframe for assessing the likelihood of 
threats as well as the species' response to those threats. 
Additionally, this timeframe allows us to reasonably forecast upcoming 
management activities that will be implemented through the CMP. The two 
scenarios used for our status determination in this final rule reflect 
both exogenous factors such as watershed condition and climatic 
changes, as well as management action feasibility and volume given 
funding and other programmatic constraints (e.g., funding and other 
resources) and policy. The scenarios incorporate a status quo level of 
management through the CMP, as well as potentially increased levels of 
management through future conservation actions that could take place 
throughout the future. Each scenario was based on a 30-year timeframe 
and each includes climate change impacts and other factors impacting 
the Apache trout, implementation of the CMP, and scientific and 
technological advancement. The two scenarios from the SSA report that 
we evaluated are:
    Scenario 3 (Sustained Management, i.e., status quo): Recovery and 
conservation efforts continue at sustained levels, which during the 
years 2000-2020 were proven to be beneficial to Apache trout recovery. 
This level of management will be maintained into the future as 
prescribed by and implemented through the CMP. Thus, actions continue 
and are effective at reducing some threats. This includes legally 
required actions and those voluntarily agreed to in the CMP. Barrier 
construction, population expansion, and nonnative trout removals occur 
at levels required to meet recovery criteria (30 pure populations, or 
similar) and are maintained thereafter. USFWS assistance to the WMAT 
continues. Some funding sources disappear (e.g., National Fish and 
Wildlife Foundation Apache Trout Keystone Initiative), but other 
funding sources emerge (e.g., National Fish Habitat Act). This scenario 
represented the status quo scenario with approximately the same level 
of resources and management action as a 2000-2020 baseline.
     Barrier installation and maintenance continues at 2000-
2020 levels. The number of viable Apache trout populations and 
metapopulations

[[Page 72753]]

increases to meeting recovery goals and is maintained after delisting.
     Effectiveness of land management policies for stream 
ecosystem and threatened species is initially maintained through 
delisting due to the CMP agreement in place. Across the Apache trout 
range, watershed functional conditions are maintained or improved, 
riparian and instream habitat are maintained or improved in quality, 
and stream temperatures are maintained or improved to support Apache 
trout due to protections during land management planning and 
implementation.
     Because of climate change, stream temperatures become 
warmer, droughts continue to become more frequent and severe, risk of 
wildfire and post-fire debris flow increases, snowpack decreases but 
increased rain on snow events occur, and summer monsoon rains become 
more intense.
    Scenario 4 (Increased Management): Recovery and conservation 
efforts continue but at levels increased slightly from 2000-2020 
baseline levels that are beneficial to the species. Management actions 
continue and some become effective at reducing some threats. After 
barrier construction, population expansion, and nonnative trout 
removals initially occur at levels required to meet recovery criteria 
(30 pure populations, or similar) and Apache trout are delisted, the 
level of actions is maintained due to the CMP in place, but also 
increases due to emergence of new research and technology. USFWS 
assistance to the WMAT continues. Legislation emerges resulting in new 
funding sources for fish habitat projects (e.g., National Fish Habitat 
Act), and there is broad implementation of the Four Forest Restoration 
Initiative, Black River Restoration Environmental Assessment, and FAIR 
Forest Management Plan (fuels management) that are beneficial to 
watershed functional conditions and reduced wildfire risk.
     Barrier installation and maintenance increase slightly 
from 2000-2020 levels due to new technology that increases 
effectiveness and reduces cost and maintenance. The number of viable 
Apache trout populations increases and one large metapopulation is 
realized to meet and exceed recovery goals.
     Effectiveness of land management policies for stream 
ecosystem and threatened species is initially maintained through 
delisting due to the CMP in place. Across the Apache trout range, 
watershed functional conditions are improved, riparian and instream 
habitat are improved in quality, and stream temperatures are improved 
(riparian restoration and recovery) to support Apache trout due to 
protections during land management planning and implementation.
     Because of climate change, stream temperatures become 
warmer, droughts continue to become more frequent and severe, risk of 
wildfire and post-fire debris flow increases, snowpack decreases but 
more rain on snow events occur, and summer monsoon rains become more 
intense.
    For each scenario provided in the SSA report, Apache trout core 
team members indicated in an online survey the overall impact of each 
scenario on populations across the species' range, or subsets of the 
range with which they are familiar, using their best professional 
judgment. Each core team expert responded to survey questions in terms 
of what the condition--described as a GPA--of each Apache trout 
population (or currently unoccupied stream) would be, based on the 
grading scale used to describe current conditions, above, under each of 
the five future condition scenarios after a 30-year timeframe. GPAs 
were summarized across populations to assess the influence of each 
scenario on the rangewide status of Apache trout.
    When survey responses of future condition were summarized 
(averaged) across populations for scenarios 3 and 4 to infer a future 
rangewide condition of the Apache trout under each scenario, the future 
condition of the species under scenario 4 (increased management) was 
expected to improve compared to scenario 3 (sustained management), 
similar to that of individual populations.
    Under scenario 3, which maintains the same level of conservation 
management and actions as are currently being implemented through the 
CMP, the condition of the species was estimated at a GPA score of 2.53. 
This average score, however, includes variation in populations. Under 
scenario 3, we project the future condition of the majority of the 
relict populations would modestly decline, resulting in slightly lower 
resiliency. These declines are attributed to potential impacts from 
climate change and its effect on forest fires that are not expected to 
be offset by other management actions (e.g., nonnative trout 
eradication) which are generally not currently needed in relict 
populations. On the other hand, we project that some replicate 
populations would have slightly better condition in the future compared 
to current conditions due to completion of ongoing nonnative trout 
eradication efforts (e.g., West Fork Black River [lower]) and planned 
replacement of nonfunctional conservation barriers (e.g., West Fork 
Little Colorado River). Overall, relative to current condition, the 
species' overall resiliency under scenario 3 may modestly decline. 
Therefore, even though redundancy would remain the same, representation 
may be slightly reduced due to the projected decline of the Apache 
trout relict populations under scenario 3.
    Under scenario 4, which evaluates an increased level of 
conservation management versus what is currently being implemented 
through the CMP, the future condition of the Apache trout would be 
essentially unchanged with a GPA score of 2.86. This represents a 
nominal decrease when compared to the current condition GPA score of 
2.89. Under scenario 4, we project slight improvement in future 
conditions across some populations with other populations remaining 
essentially unchanged or experiencing slight declines. Some natural 
processes (e.g., purging of nonnative alleles) and planned management 
actions not represented in scenarios 3 and 4 (e.g., new population 
establishment, metapopulation creation) are expected to occur that will 
further improve specific and range-wide GPA scores. Further, average 
grant funding to support field crews and conservation projects obtained 
during 2020-2022 also far exceeds the average annual funding obtained 
for similar work during the 2000-2020 baseline period. Thus, future 
condition scores for scenarios 3 and 4 likely underestimate actual 
future conditions for the species as additional populations are created 
and maintained, nonnative trout populations are eradicated, and 
populations with low levels of introgression purge nonnative alleles 
over time.
    Under both scenarios, the CMP plays an important role in 
determining the species' future condition and the management of threats 
to Apache trout. The CMP was drafted and signed to ensure that current 
conservation efforts will continue in perpetuity. The signing of the 
CMP has a demonstrable effect on the species' overall status with 
current management level resulting in only a slight and modest decline 
under scenario 3 (the status quo scenario). Scenario 4, in which 
funding for conservation efforts would increase, results in maintaining 
the species' overall future condition. Overall, the result of our 
future scenarios analysis demonstrates the importance of continued 
implementation of the CMP to ensure both the maintenance of current 
populations and habitat, the

[[Page 72754]]

restoration of degraded habitat, and the establishment of new 
populations.
    For climate-related threats to Apache trout that are not able to be 
actively managed, we relied on a model developed to inform the 
magnitude of effects that these factors might have through the 
foreseeable future. For increased stream temperatures, our model 
suggested that most streams currently occupied by Apache trout, or 
unoccupied but designated as recovery streams, are not temperature 
limited, and that suitability improved when 2080s projections of 
temperature alone were considered because some headwater reaches 
appeared to be currently too cold for occupancy. Most habitat patches 
were not limited by warm stream temperatures because the habitat 
designated for species recovery is upstream of protective fish passage 
barriers that are far enough upstream to not be temperature limiting 
now or into the 2080s (Avenetti et al. 2006, p. 213; USFWS 2009, p. 19; 
USFWS 2022b, pp. 118-127). In fact, the effect of temperature on 
juvenile Apache trout occupancy suggested that streams can be too cold, 
and model projections of stream temperature in the 2080s increased the 
amount of suitable habitat in some streams because of the unimodal 
response to temperature. This suggests cold temperatures can be 
limiting Apache trout populations in some streams, and any warming may 
benefit them in headwater reaches--at least up until the 2080s.
    It was only when future changes in precipitation were considered in 
tandem with stream temperature that habitat suitability decreased into 
the 2080s. Many habitat patches that are currently occupied by the 
species are projected to remain suitable into the 2080s, which suggests 
their resiliency is only limited by the size of the patch they 
currently occupy (Peterson et al. 2014, pp. 564-268; Isaak et al. 2015, 
pp. 2548-2551; USFWS 2022a, pp. 135-140). However, when projections of 
reduced precipitation were also considered, habitat suitability 
decreased in Apache trout streams. This is not surprising given that 
stream intermittency and drought have impacted some populations in the 
past (Robinson et al. 2004, pp. 15-17; Williams et al. 2020, entire), 
and less precipitation, and thus streamflow, would exacerbate these 
impacts, especially since the Southwest is anticipated to experience 
novel and mega-drought conditions in future climates (Crausbay et al. 
2020, pp.337-348; Williams et al. 2020, entire).
    Precipitation in the White Mountains primarily falls as winter snow 
and summer monsoon rain (Mock 1996, pp. 1113-1124). However, decreases 
in precipitation due to climate change are expected to occur in winter 
in the form of snow (Easterling et al. 2017, p. 207), and decreases in 
snowpack are likely to negatively impact stream baseflows and summer 
temperatures. Hydrologic models linked to climate models show future 
precipitation increasingly falling as rain, higher frequency of rain-
on-snow, and increased snowmelt rates, all of which lead to increased 
overland runoff to streams and less infiltration to groundwater. Less 
groundwater storage leads to less groundwater discharge to streams in 
late summer and early autumn (Huntington and Niswonger 2012, pp. 16-
18). The summer monsoon season can add precipitation, but at much 
warmer temperatures regardless of whether it occurs as overland flow or 
through shallow groundwater discharge pathways.
    While snow melt can result in overland flow during spring runoff, 
it also infiltrates into groundwater and does so at near freezing 
temperatures (at or just above 0 [deg]C (32 [deg]F); Potter 1991, pp. 
847, 850). Thus, any groundwater contributions to streams that 
originate from snowmelt are likely to have a stronger cooling effect on 
stream temperatures released over longer time periods than overland 
flow from either snowmelt or monsoon rains. If snowpack is reduced in 
the future it is likely that groundwater return flows may occur earlier 
and be less overall, thus providing less of a cooling effect into late 
summer, especially prior to monsoon rains (Overpeck and Bonar 2021, pp. 
139-141).

Determination of the Apache Trout's Status

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species meets the definition of an endangered species or a 
threatened species. The Act defines an ``endangered species'' as a 
species that is in danger of extinction throughout all or a significant 
portion of its range, and a ``threatened species'' as a species that is 
likely to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range. The Act requires 
that we determine whether a species meets the definition of an 
endangered species or a threatened species because of any of the 
following factors: (A) The present or threatened destruction, 
modification, or curtailment of its habitat or range; (B) 
Overutilization for commercial, recreational, scientific, or 
educational purposes; (C) Disease or predation; (D) The inadequacy of 
existing regulatory mechanisms; or (E) Other natural or manmade factors 
affecting its continued existence.

Status Throughout All of Its Range

    The Apache trout is a species endemic to multiple river basins in 
eastern Arizona. Due to conservation efforts undertaken within these 
past decades, the Apache trout now encompasses 30 genetically pure 
populations across 3 basins and 6 subbasins. While these populations 
will continue to be impacted by potential invasion of nonnative trout 
and debris runoff from wildfire and climate change, construction and 
maintenance of conservation barriers and restocking efforts have 
contributed and will continue to contribute to restoration of habitats 
and populations. Currently, these 30 Apache trout populations are 
assessed to possess good conditions (2.89 on a 4.0 grading scale). 
Within these 30 populations, relict populations have an average GPA of 
2.93, and replicate populations have an average GPA of 2.85. These 
results demonstrate that both types of populations contain moderate to 
good condition with the relict populations rated slightly higher.
    Apache trout representation is best demonstrated within the 17 
relict populations across five subbasins. While further studies would 
need to be conducted to ascertain the genetic uniqueness of each relict 
population, these populations are not derived from known populations, 
suggesting that some of these populations could represent unique 
genetic lineages for the species. To further preserve the genetic 
diversity of the species, the Service and our partners have established 
replicate populations within and alongside other subbasins, resulting 
in the total of 30 populations across six subbasins. As noted above in 
our resiliency discussion, through continuous monitoring, restoration 
of habitat, and, if needed, restocking, these populations are rated as 
being in fair or good condition. The genetic uniqueness of these 
populations helps maintain the diverse gene pool of the species, giving 
the species greater adaptive capacity to respond to environmental 
changes.
    The presence of multiple relict and replicate populations across 
different subbasins demonstrates a high level of redundancy. Redundancy 
is further enhanced through the creation of new replicate populations 
from relict populations. These populations are created in adjacent 
subbasins, providing greater protection for the species against 
catastrophic events that may impact

[[Page 72755]]

individual subbasins. Overall, the presence of 30 populations across 
six subbasins, with all being rated as fair to good condition, provide 
the Apache trout with sufficient redundancy to withstand catastrophic 
events that may impact the species.
    Lastly, as noted earlier, we have met all criteria that the 
recovery plan recommended for delisting. This represents a significant 
recovery of the species. Recovery plan criteria are meant to function 
as guidance for recovery rather than hard metrics that must be met. 
Instead, we use the best available information to determine the status 
of the species.
    Overall, the Apache trout now consists of multiple, sufficiently 
resilient populations across subbasins encompassing a large percentage 
of the species' historical range. Furthermore, while long-term threats 
such as nonnative trout species will continue to persist, continued 
management of conservation barriers will ensure that the threats do not 
negatively impact the species. Accordingly, we conclude that the 
species is not currently in danger of extinction, and thus does not 
meet the definition of an endangered species, throughout its range.
    In considering whether the species meets the definition of a 
threatened species (likely to become an endangered species within the 
foreseeable future) throughout its range, we identified the foreseeable 
future of Apache trout to be 30 years based on our ability to reliably 
predict the likelihood of future threats as well as the species' 
response to future threats, and because it is a timeframe in which we 
can reasonably forecast upcoming management activities as they will be 
implemented through the CMP. Our analysis of future condition 
emphasized the importance of continued management of the conservation 
barriers and removal of nonnative trout. Species viability modestly 
declined in scenario 3, and increased in scenario 4, due to increases 
in management efforts. Scenarios 3 and 4 are both scenarios in which 
the CMP is being implemented. In our assessment, we found that the CMP, 
while voluntary in nature, plays a vital role in continuing to improve 
the status of the Apache trout into the future. For example, WMAT, 
AZGFD, and the USFWS are currently working together to mechanically 
remove brook trout from the upper West Fork Black River population, 
including Thompson Creek, in case chemical renovation of this system is 
not ultimately approved.
    This effort represents just one of the ongoing efforts to improve 
the species' overall condition, as well as the willingness of Federal, 
State, Tribal, and private partners to continue these conservation 
efforts into the future. Other collaborative conservation efforts 
include brook and brown trout removal projects, fish passage 
improvements, riparian habitat restoration projects, and conservation 
barrier replacements or old barrier removal projects on Tribal, State, 
and Federal lands. WMAT and the USFWS are currently working to 
eradicate brown trout from Aspen, Big Bonito, Coyote, Little Bonito, 
and Little Diamond creeks. All partners are working on fish passage 
improvements, including removing four conservation barriers on 
Hayground, Home, and Stinky creeks and replacing six culverts on 
Paradise and Thompson creeks to improve fish passage, increase occupied 
extents, and allow for metapopulation dynamics among connected 
populations. Riparian habitat restoration projects are underway on 
Boggy and Lofer creeks and being planned for Flash Creek, South Fork 
Little Colorado River, and West Fork Black River. Finally, conservation 
barrier replacements are underway that will protect the populations in 
Aspen, Boggy/Lofer, Coyote, Crooked, Flash, Little Bonito, Little 
Diamond, Ord, Paradise, and Wohlenberg creeks.
    Apache trout populations with high resiliency will continue to be 
the focus of active habitat management, such as riparian vegetation 
management and habitat restoration, to improve or ensure their climate 
resiliency into the 2080s and potentially beyond. Most habitat patches 
are not currently limited by warm stream temperatures. Habitat 
designated for Apache trout recovery largely occurs in colder, upstream 
areas above conservation barriers (Avenetti et al. 2006, p. 213; USFWS 
2009, p. 19), and even with increasing stream temperatures through the 
foreseeable future many of these areas will not be limited by warmer 
temperatures into the 2080s. As described previously, the effect of 
temperature on juvenile Apache trout occupancy suggests that many 
streams can in fact be too cold, and projections of stream temperature 
into the 2080s in some cases increased the amount of suitable habitat 
in some streams because of the unimodal response to temperature.
    Overall, the signing of the CMP in 2021 ensures that conservation 
for the Apache trout will remain for the long-term. With the CMP in 
place and considering future effects from climate change and the 
response of Apache trout to these effects, we conclude that the Apache 
trout will exhibit sufficient resiliency, redundancy, and 
representation to maintain viability for the foreseeable future. 
Accordingly, we conclude that the species is not likely to become in 
danger of extinction in the foreseeable future, and thus does not meet 
the definition of a threatened species, throughout all of its range.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. Having determined that the Apache trout is not in danger of 
extinction or likely to become so in the foreseeable future throughout 
all of its range, we now consider whether it may be in danger of 
extinction (i.e., endangered) or likely to become so in the foreseeable 
future (i.e., threatened) in a significant portion of its range--that 
is, whether there is any portion of the species' range for which both 
(1) the portion is significant; and, (2) the species is in danger of 
extinction or likely to become so in the foreseeable future in that 
portion. Depending on the case, it might be more efficient for us to 
address the ``significance'' question or the ``status'' question first. 
We can choose to address either question first. Regardless of which 
question we address first, if we reach a negative answer with respect 
to the first question that we address, we do not need to evaluate the 
other question for that portion of the species' range.
    In undertaking this analysis for Apache trout, we choose to address 
the status question first. We began by identifying portions of the 
range where the biological status of the species may be different from 
its biological status elsewhere in its range. For this purpose, we 
considered information pertaining to the geographic distribution of (a) 
individuals of the species, (b) the threats that the species faces, and 
(c) the resiliency condition of populations.
    We evaluated the range of the Apache trout to determine if the 
species is in danger of extinction now or likely to become so in the 
foreseeable future in any portion of its range. Because the range of a 
species can theoretically be divided into portions in an infinite 
number of ways, we focused our analysis on portions of the species' 
range that may meet the definition of an endangered species or a 
threatened species. Although we assessed current and future conditions 
at a population scale in the SSA report, interactions between 
populations within a subbasin can be complex (i.e., in some subbasins, 
there are genetic exchanges between populations while in others,

[[Page 72756]]

populations are separated by barriers). Thus, to assess these portions 
equally, we focus our analysis here at the subbasin scale. That said, 
the current and future conditions of the populations will be used to 
discuss the conditions of the subbasins.
    Within these portions, we examined the following threats: invasive 
trout, habitat loss due to wildfire, and the effects from climate 
change, including synergistic and cumulative effects. As discussed in 
our rangewide analyses, nonnative trout and wildfire are the main 
drivers of the species' status.
    Looking across the different subbasins, all but one have the mean 
GPA of 2.83 or above under its current condition (meaning good 
conditions under our conditions metric). When examining future 
conditions, even under the worst-case scenario, with reduced management 
and no CMP, all but one subbasin have a future condition status of 
fair. While there are differences in scoring within each subbasin, at 
the subbasin scales, these subbasins possess sufficient resiliency such 
that we do not consider them to be in danger of extinction or likely to 
become so within the foreseeable future. For these subbasins, we 
assessed them to possess the same status as our rangewide analysis.
    Out of all the subbasins of the Apache trout, the Diamond subbasin 
has the lowest mean GPA of 2.33 under its current condition. However, 
under future condition, we project the species will slightly decline 
from its current condition under scenario 3. Under both scenarios 3 and 
4, the Diamond subbasin remains on the lower end of the fair rating.
    The major driver of a subbasin's status is its habitat condition 
score. Although future condition scoring does not separate demographic 
GPA from habitat GPA, we know from the current condition score that the 
limiting factor for Apache trout within the Diamond subbasin is habitat 
condition. Three of the four populations within the Diamond subbasin 
have high demographic GPAs, with high abundance and multiple age 
classes. However, the scores for habitat quality are 2.33, 2.00, 1.83, 
and 1.83, due primarily to shorter occupied stream lengths compared to 
other populations. Additionally, the streams within the Diamond 
subbasin experience a higher percentage of intermittency, meaning that 
larger portions of the stream tend to go dry during periods of drought. 
Given the continuing effects of climate change, it is likely that these 
streams will experience periods with intermittent streamflow in some 
reaches into the future.
    Although populations of the Apache trout in the Diamond subbasin 
are currently rated as being in fair condition, the low habitat quality 
(primarily due to occupied stream length being less than 11.25 km (7 
mi), estimations of intermittent stream proportions, the presence of 
brown trout, and current barrier conditions) and the potential for 
decline due to climate change could lead to elevated risk to 
populations in the foreseeable future in this portion of the range. 
Work to eradicate (and prevent reinvasion of) brown trout from two 
streams in this subbasin is underway, which, if successful, would 
result in higher habitat scores once completed (with all other scores 
remaining unchanged, the subbasin's average habitat GPA would rise to 
2.58 once the work is completed) and would reduce the risk of 
population declines in this portion of the range (USFWS 2022a, p. 101). 
However, these actions have not yet significantly improved the status 
of this subbasin, and we assessed this subbasin to be at elevated risk 
of extirpation to a degree that this portion of the range may be in 
danger of extinction within the foreseeable future.
    Given that the Diamond subbasin may be in danger of extinction 
within the foreseeable future, we next evaluated if this portion of the 
range was significant. Although every subbasin provides some 
contribution to the species' resiliency, representation, and 
redundancy, as noted above, the Diamond subbasin populations occupy a 
short stream length (30.2 km (18.8 mi)) that comprises a small portion 
of the Apache trout's overall range (10.7 percent of the Apache trout's 
overall range of 281.5 km (174.9 mi)). Ecologically, the habitats where 
these populations are found are not dissimilar to habitats found in the 
other subbasins. As in the other subbasins, Apache trout in the Diamond 
subbasin are found in headwater streams with shallow depth, relatively 
slow-moving water, and coarse, clean gravel streambeds.
    The Diamond subbasin is comprised of a mixture of replicate and 
relict populations. Although this subbasin contains relict populations, 
these and the replicate populations are associated with populations in 
the neighboring subbasins of North Fork White River and East Fork White 
River. Specifically, relict populations in the adjacent subbasin were 
used as founder stocks for the replicate populations in the Diamond 
subbasin, and the relict population in the Diamond subbasin was used to 
create a replicate population in an adjacent subbasin. Thus, through 
the process of replication of populations, the genetic contribution of 
the Diamond subbasin is dispersed across other subbasins.
    Overall, the Diamond subbasin's short stream length relative to the 
species' overall range, lack of ecological uniqueness, proximity to 
other subbasins, and existence of replicate populations lead us to 
conclude that this portion of the Apache trout's range does not 
represent a significant portion of the range; therefore, we find that 
there are no portions of the species' range that warrant further 
consideration, and the species is not in danger of extinction or likely 
to become so in the foreseeable future in any significant portion of 
its range. This does not conflict with the courts' holdings in Desert 
Survivors v. Department of the Interior, 321 F. Supp. 3d 1011, 1070-74 
(N.D. Cal. 2018), and Center for Biological Diversity v. Jewell, 248 F. 
Supp. 3d 946, 959 (D. Ariz. 2017) because, in reaching this conclusion, 
we did not apply the aspects of the Final Policy on Interpretation of 
the Phrase ``Significant Portion of Its Range'' in the Endangered 
Species Act's Definitions of ``Endangered Species'' and ``Threatened 
Species'' (79 FR 37578; July 1, 2014), including the definition of 
``significant'' that those courts' decisions held to be invalid.

Determination of Status

    Our review of the best available scientific and commercial 
information indicates that the Apache trout does not meet the 
definition of an endangered species or a threatened species in 
accordance with sections 3(6) and 3(20) of the Act. In accordance with 
our regulations at 50 CFR 424.11(e)(2) currently in effect, the Apache 
trout has recovered to the point at which it no longer meets the 
definition of an endangered species or a threatened species. Therefore, 
we are removing the Apache trout from the Federal List of Endangered 
and Threatened Wildlife.

Effects of This Rule

    This rule revises 50 CFR 17.11(h) by removing the Apache trout from 
the Federal List of Endangered and Threatened Wildlife. On the 
effective date of this rule (see DATES, above), the prohibitions and 
conservation measures provided by the Act, particularly through 
sections 7 and 9 or any 4(d) rule, will no longer apply to the Apache 
trout. Federal agencies will no longer be required to consult with the 
Service under section 7 of the Act in the event that activities they 
authorize, fund, or carry out may affect the Apache trout.

[[Page 72757]]

This rule will also remove the Federal regulations related to the 
Apache trout's 4(d) rule at 50 CFR 17.44(a).

Post-Delisting Monitoring

    Section 4(g)(1) of the Act requires us, in cooperation with the 
States, to implement a monitoring program for not less than 5 years for 
all species that have been recovered. Post-delisting monitoring (PDM) 
refers to activities undertaken to verify that a species delisted due 
to recovery remains secure from the risk of extinction after the 
protections of the Act no longer apply. The primary goal of a PDM is to 
monitor the species to ensure that its status does not deteriorate, and 
if a decline is detected, to take measures to halt the decline so that 
proposing it as endangered or threatened is not again needed. If at any 
time during the monitoring period data indicate that protective status 
under the Act should be reinstated, we can initiate listing procedures, 
including, if appropriate, emergency listing.
    We have prepared a PDM plan for the Apache trout. We published a 
notice of availability of a draft PDM plan with the proposed delisting 
rule (88 FR 54548; August 11, 2023), and we did not receive any 
comments on the plan. Therefore, we consider the plan final. As 
discussed in the proposed rule, the PDM plan for Apache trout will 
monitor populations following the same sampling protocol used by 
cooperators prior to delisting. Monitoring will consist of tracking 
Apache trout distribution and abundance and potential adverse changes 
to Apache trout habitat due to environmental or anthropogenic factors. 
Post-delisting monitoring will occur for a 10-year period, beginning 
after the final delisting rule is published, and will include the 
implementation of (1) Apache Trout Monitoring Plan (``Monitoring 
Plan,'' Dauwalter et al. 2017b, entire) and (2) Apache Trout CMP, 
Apache Trout Cooperative Management Plan Workgroup 2021, entire) for 
the duration of the PDM period. Both plans are currently being 
implemented and will continue to be implemented into the future. The 
Monitoring Plan describes population and habitat survey methods, data 
evaluation methods, and monitoring frequency for each population. The 
CMP describes roles, responsibilities, and evaluation and reporting 
procedures by the cooperators. Together these plans will guide 
collection and evaluation of pertinent information over the PDM period 
and will be implemented jointly by the USFWS, WMAT, AZGFD, USFS, and 
Trout Unlimited. Both documents will be available upon the publication 
of this rule at https://www.regulations.gov, under the Docket No. FWS-
R2-ES-2022-0115.
    During the PDM period, if declines in the Apache trout's protected 
habitat, distribution, or persistence were detected, the Service, 
together with other PDM partners, would investigate causes of the 
declines, including considerations of habitat changes, human impacts, 
stochastic events, or any other significant evidence. The outcome of 
the investigation would be to determine whether the Apache trout 
warranted expanded monitoring, additional research, additional habitat 
protection, or relisting as an endangered or threatened species under 
the Act. If relisting the Apache trout were warranted, emergency 
procedures to relist the species may be followed, if necessary, in 
accordance with section 4(b)(7) of the Act.

Required Determinations

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951, May 4, 1994), Executive Order 13175 
(Consultation and Coordination with Indian Tribal Governments), the 
President's memorandum of November 30, 2022 (Uniform Standards for 
Tribal Consultation; 87 FR 74479, December 5, 2022), and the Department 
of the Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with federally recognized 
Tribes and Alaska Native Corporations on a government-to-government 
basis. In accordance with Secretary's Order 3206 of June 5, 1997 
(American Indian Tribal Rights, Federal-Tribal Trust Responsibilities, 
and the Endangered Species Act), we readily acknowledge our 
responsibilities to work directly with Tribes in developing programs 
for healthy ecosystems, to acknowledge that Tribal lands are not 
subject to the same controls as Federal public lands, to remain 
sensitive to Indian culture, and to make information available to 
Tribes.
    The Apache trout occurs on area managed by the WMAT. As noted 
above, we have coordinated with WMAT in conserving and protecting the 
Apache trout's habitat and populations, and we have coordinating with 
WMAT throughout the development of the PDM plan. Furthermore, WMAT 
participated in the development of the SSA. Going forward, we 
anticipate our partnership with WMAT to continue into the future 
regardless of any potential changes in the Apache trout's status under 
the Act.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at https://www.regulations.gov and upon request from 
the Arizona Ecological Services Office (see FOR FURTHER INFORMATION 
CONTACT).

Authors

    The primary authors of this rule are staff members of the Service's 
Species Assessment Team and the U.S. Fish and Wildlife Service Arizona 
Fish and Wildlife Conservation Office.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Plants, 
Reporting and recordkeeping requirements, Transportation, Wildlife.

Regulation Promulgation

    Accordingly, we amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245, unless 
otherwise noted.


Sec.  17.11   [Amended]

0
2. In Sec.  17.11, in paragraph (h), amend the List of Endangered and 
Threatened Wildlife by removing the entry for ``Trout, Apache'' under 
``Fishes''.

0
3. In Sec.  17.44, revise the heading of paragraph (a) to read as 
follows:


Sec.  17.44   Species-specific rules--fishes.

    (a) Lahontan cutthroat trout and Paiute cutthroat trout 
(Oncorhynchus clarkii henshawi and Oncorhynchus clarkii seleniris). * * 
*
* * * * *

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2024-19330 Filed 9-5-24; 8:45 am]
BILLING CODE 4333-15-P