Endangered and Threatened Wildlife and Plants; Reclassification of the Humpback Chub From Endangered to Threatened With a Section 4(d) Rule, 57588-57610 [2021-20964]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 198 (Monday, October 18, 2021)]
[Rules and Regulations]
[Pages 57588-57610]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-20964]



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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2018-0081; FF09E22000 FXES11130900000 212]
RIN 1018-BD47


Endangered and Threatened Wildlife and Plants; Reclassification 
of the Humpback Chub From Endangered to Threatened With a Section 4(d) 
Rule

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are 
reclassifying the humpback chub (Gila cypha) from endangered to 
threatened under the Endangered Species Act of 1973, as amended (Act), 
due to substantial improvements in the species' overall status since 
its original listing as endangered in 1974. This action is based on a 
thorough review of the best available scientific and commercial 
information available, which indicates that the humpback chub no longer 
meets the definition of an endangered species under the Act. The 
humpback chub will remain protected as a threatened species under the 
Act. We are also finalizing a rule under section 4(d) of the Act that 
provides for the conservation of the humpback chub.

DATES: This rule is effective November 17, 2021.

ADDRESSES: This final rule, supporting documents we used in preparing 
this rule, and public comments we received are available on the 
internet at https://www.regulations.gov under Docket No. FWS-R6-ES-2018-
0081. Persons who use a telecommunications device for the deaf (TDD) 
may call the Federal Relay Service at 800-877-8339.

FOR FURTHER INFORMATION CONTACT: Tom Chart, Director, telephone: 303-
236-9885. Direct all questions or requests for additional information 
to HUMPBACK CHUB QUESTIONS, U.S. Fish and Wildlife Service, Upper 
Colorado River Endangered Fish Recovery Program, P.O. Box 25486, DFC, 
Lakewood, CO 80225. Persons who use a TDD may call the Federal Relay 
Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, if a species is 
determined to no longer be an endangered or threatened species, we may 
reclassify the species or remove it from the Federal Lists of 
Endangered and Threatened Wildlife and Plants due to recovery. A 
species is an ``endangered species'' for purposes of the Act if it is 
in danger of extinction throughout all or a significant portion of its 
range and is a ``threatened species'' if it is likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range. We are reclassifying the humpback 
chub from endangered to threatened (i.e., ``downlisting'') because we 
have determined that the species is no longer in danger of extinction 
throughout all or a significant portion of its range. Downlisting a 
species can only be completed by issuing a rule.
    What this document does. This rule reclassifies the humpback chub 
from endangered to threatened (i.e., to ``downlists'' the species), 
with a rule issued under section 4(d) of the Act, based on the species' 
current status, which has been improved through implementation of 
conservation actions.
    The basis for our action. Under the Act, we can determine that a 
species is an endangered or threatened species based on any one or more 
of the following five factors or the cumulative effects thereof: (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. Based on an 
assessment of the best available information regarding the status of 
and threats to the humpback chub, we have determined that the species 
no longer meets the definition of endangered under the Act, but does 
meet the definition of threatened.
    We are promulgating a section 4(d) rule. The rule we are 
promulgating under section 4(d) of the Act (``4(d) rule'') provides 
exceptions to take prohibitions for activities that will further 
recovery of the species. This final rule recognizes that, based on the 
best available science, the humpback chub no longer meets the 
definition of an endangered species, but will remain protected as a 
threatened species under the Act. This progress towards recovery is a 
result of conservation efforts implemented by stakeholders. 
Collaborative conservation efforts have reduced the intensity of 
threats to the species and improved its population numbers. The 4(d) 
rule will accommodate recovery activities such as nonnative control 
efforts, habitat restoration, monitoring, research, stocking, and 
refuge maintenance.

Previous Federal Actions

    On March 11, 1967, the Secretary of the Interior published a final 
rule (32 FR 4001) listing the humpback chub as an endangered species in 
accordance with the Endangered Species Preservation Act of 1966 (80 
Stat. 926; 16 U.S.C. 668aa(c)). Subsequently, the humpback chub 
retained classification as an endangered species under the Endangered 
Species Conservation Act of 1969 (16 U.S.C. 668aa) and the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.), and on 
January 4, 1974, the species was included in a final rule (39 FR 1158) 
establishing a list of endangered native wildlife at 50 CFR part 17. On 
March 21, 1994, we designated critical habitat for humpback chub along 
610 kilometers (km) (379 miles (mi)) of the Colorado River basin (59 FR 
13374).
    We issued the first recovery plan for the humpback chub on August 
22, 1979. We revised the recovery plan on September 19, 1990, and we 
further amended and supplemented the 1990 revised plan with new 
recovery goals on August 1, 2002. The recovery criteria presented in 
the 2002 recovery plan remain reasonable measures to gauge progress 
towards recovery and a valuable reference as we refine our vision of 
recovery for the humpback chub, and work to update the recovery plan.
    On January 22, 2020, we proposed to downlist the humpback chub from 
``endangered'' to ``threatened'' (85 FR 3586). Please refer to that 
proposed rule for a detailed description of the Federal actions 
concerning this species that occurred prior to January 22, 2020.

Summary of Changes From the Proposed Rule

    As explained below under Summary of Comments and Recommendations, 
we made several changes in this final rule in response to public 
comments we received on our January 22, 2020, proposed rule (85 FR 
3586). In incorporating the primary changes resulting from public 
input, we:
     Completed minor editorial changes and reorganized various 
sections of the rule to increase readability;
     Updated population status for all extant populations to 
include the most recent monitoring data;
     Revisited the analysis of future water availability and 
included newly available climate information;
     Revisited management actions performed by the two multi-
stakeholder programs and included analysis of

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actions newly implemented or planned, including, but not limited to, 
actions affecting river flows, food supply, and nonnative fish;
     Considered new information regarding the continued 
existence of the Upper Basin Recovery Program and funding for the two 
multi-stakeholder programs implementing management actions to benefit 
humpback chub; and
     Revisited our analysis of the species' status in a 
significant portion of its range based on the ruling of the court in 
Center for Biological Diversity v. Everson, 2020 WL 437289 (D.D.C. Jan. 
28, 2020).

We have incorporated this information below under Summary of Biological 
Status and Threats and Determination of Humpback Chub Status, in this 
rule. Additionally, we updated the species status assessment (SSA) 
report to clarify the historical and current species range (Service 
2018b, entire).

Supporting Documents

    A species status assessment (SSA) team prepared an SSA report for 
the humpback chub. The SSA team was composed of Service biologists, in 
consultation with other species experts. 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 actions under the Act, we sought peer review of the SSA report. 
The Service sent the SSA report to 3 independent peer reviewers and 
received 3 responses. The purpose of peer review is to ensure that our 
reclassification determinations and 4(d) rules are based on 
scientifically sound data, assumptions, and analyses. The peer 
reviewers have expertise in the biology, habitat, and threats to the 
species. The Service also sent the SSA report to over 25 State, Tribal, 
Federal, and private partners, including scientists with expertise in 
desert river biology, ecology, and hydrology, for review. We received 
review from 29 individuals across 12 partner organizations (Service 
2018b, pp. iv-v).

Final Reclassification Determination

Background

    It is our intent to discuss only those topics directly related to 
downlisting humpback chub in this rule. The citations represent only 
the sources required to support this action or to provide context for 
it, and are not the sum total of all literature pertaining to the 
species. For more information on the description, taxonomy, biology, 
ecology, and habitat of the species, please refer to the species status 
assessment (SSA) report for the humpback chub (Service 2018b, entire), 
as well as the materials cited in this rule. These documents will be 
available as supporting materials on https://www.regulations.gov under 
Docket No. FWS-R6-ES-2018-0081.
    The humpback chub is a fish endemic to the warm-water portions of 
the Colorado River basin of the southwestern United States. The 
humpback chub lives in discrete, rocky, canyon-bound river reaches 
characterized by swift currents in portions of Utah, Colorado, and 
Arizona. Multiple adaptations allow the humpback chub to survive the 
highly variable flow conditions of these desert river ecosystems, such 
as a long lifespan of approximately 20 to 40 years, large body size up 
to 480 millimeters (mm) (19 inches (in)), high reproductive potential 
by producing up to 2,500 eggs per year, tolerance to a wide range of 
water qualities, and a variable diet.
    There are currently five extant, or occupied, humpback chub 
populations: Desolation and Gray Canyons (the Green River in Utah), 
Black Rocks (the Colorado River in Colorado), Westwater Canyon (the 
Colorado River in Utah), Cataract Canyon (the Colorado River in Utah), 
and Grand Canyon (the Colorado and Little Colorado Rivers in Arizona). 
Although it provides suitable habitats for humpback chub, the Dinosaur 
National Monument population is extirpated. Five of these populations 
(the Dinosaur National Monument, Desolation and Gray Canyons, Black 
Rocks, Westwater Canyon, and Cataract Canyon populations) are in the 
upper basin, and one population (the Grand Canyon population) is in the 
lower basin.

Recovery

    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 List.
    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 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.
    We published the first recovery plan for the humpback chub in 1979, 
and published an updated plan in 1990 (Service 1979; Service 1990). In 
2002, the humpback chub recovery goals supplemented and amended the 
1990 recovery plan, and provided objective and measurable demographic 
criteria and recommendations for site-specific management actions 
needed for recovery (Service 2002). For detailed description of 
recovery planning for the humpback chub and descriptions of the 2002 
recovery criteria, please refer to the Recovery Planning and Recovery 
Criteria section in the January 22, 2020, proposed rule (85 FR 3586).
    The current status of humpback chub partially meets the 2002 
recovery

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criteria. Many demographic criteria are met by the five extant 
populations of humpback chub, which have not declined significantly 
over the past decade. However, recovery criteria are not fully met 
because the adult population of Dinosaur National Monument declined and 
the population is now considered extirpated. We expect to revise the 
recovery plan for humpback chub when this rulemaking is complete in 
order to incorporate the new scientific information.

Regulatory and Analytical Framework

Regulatory Framework

    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 is 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 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. We consider these same five 
factors in downlisting a species from endangered to threatened (50 CFR 
424.11(c) through (e)).
    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 expected response by the species, 
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 now and in 
the foreseeable future.
    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. The term 
``foreseeable future'' extends only so far into the future as we can 
reasonably determine that both the future threats and the species' 
responses to those threats are likely. In other words, the foreseeable 
future is the period of time in which we can make reliable predictions. 
``Reliable'' does not mean ``certain''; it means sufficient to provide 
a reasonable degree of confidence in the prediction. Thus, a prediction 
is reliable if it is reasonable to depend on it when making decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.

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 
threats to the species. The SSA report does not represent a decision by 
the Service on whether the species should be listed as an endangered or 
threatened species under the Act. It does, however, 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. The following is a summary of 
the key results and conclusions from the SSA report; the full SSA 
report can be found at Docket No. FWS-R6-ES-2018-0081 on https://www.regulations.gov.
    To assess humpback chub viability, we used the three conservation 
biology principles of resiliency, redundancy, and representation 
(Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency supports the 
ability of the species to withstand environmental and demographic 
stochasticity (for example, wet or dry, warm or cold years), redundancy 
supports the ability of the species to withstand catastrophic events 
(for example, droughts, large pollution events), and representation 
supports the ability of the species to adapt over time to long-term 
changes in the environment (for example, climate changes). In general, 
the more resilient and redundant a species is and the more 
representation it has, the more likely it is to sustain populations 
over time, even under changing environmental conditions. 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 the 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

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sustain populations in the wild over time. We use this information to 
inform our regulatory decision.

Summary of Biological Status and Threats

    The following discussion is a summary of the results and 
conclusions from the SSA report for the humpback chub, which contains a 
more complete description of our scientific analysis (Service 2018b, 
entire).
    For our analysis, we identified the species' ecological 
requirements for survival and reproduction at the individual, 
population, and species levels, and described the factors, both 
positive and negative, that influence the viability of the humpback 
chub, currently and into the future (Service 2018b, entire). We 
evaluated the species' current levels of resiliency, redundancy, and 
representation, and projected plausible changes to these ``3Rs'' into 
the future (Service 2018b, entire). Below, we summarize the results of 
our analysis. Please refer to the SSA report (Service 2018b, entire) 
and the Summary of Biological Status and Threats section in the 
proposed rule (85 FR 3586-3594; January 22, 2020) for a more detailed 
discussion of the factors affecting the humpback chub and its 
viability.

Summary of Species Needs

    Individual humpback chub need diverse, rocky, canyon river habitat 
for spawning, rearing, feeding, and sheltering; suitable river flow and 
water temperature regimes for spawning, egg incubation, larval 
development, and growth; and an adequate and reliable food supply, 
including aquatic and terrestrial insects, crustaceans, and plant 
material (Service 2018b, pp. 15-33). Humpback chub populations need: 
Habitats with few predatory nonnative fish species, allowing the young 
to survive and recruit; suitable water quality with few toxic inputs, 
such as fire ash or other contaminants, supporting survival of all life 
stages; and unimpeded range and connectivity between discrete canyon 
habitats, providing free movement of individuals among populations. At 
the species level, the humpback chub needs multiple populations to 
provide adequate redundancy against potential catastrophic events and 
sufficient genetic diversity (representation) to ensure adaptive traits 
of the species (Service 2018b, pp. 15-33).

Summary of Species Current Condition

    As documented in more detail in our SSA report (Service 2018b, 
entire), to evaluate the current condition of the humpback chub, we 
evaluated a number of stressors that influence the resiliency of 
populations. The stressors that influence resiliency of humpback chub 
populations include river flows (Factor A) and predatory nonnative fish 
(Factor C) in the upper basin populations; and river flows (Factor A), 
water temperature (Factor A), food supply (Factor A), and predatory 
nonnative fish (Factor C) in the lower basin (Service 2018b, pp. 34-
100). Some stressors, such as low river flows and warm water 
temperatures, may also act cumulatively to increase the impact of 
predatory nonnative fish. Certain needs or stressors require continued 
management, such as river flow and nonnative fish in all five extant 
populations, and water temperature and food supply in the Grand Canyon 
population. Ongoing management actions are primarily undertaken by two 
multi-stakeholder management programs, the Upper Colorado River 
Endangered Fish Recovery Program (Upper Basin Recovery Program) and the 
Glen Canyon Dam Adaptive Management Program (Glen Canyon Dam AMP). 
Below, we summarize the current condition for the species first in the 
upper basin and then in the lower basin, with more detail provided in 
our SSA report (Service 2018b, pp. 34-124).
    Summary of Current Conditions in the Upper Basin--Currently, four 
populations of humpback chub occur in the upper basin (Desolation and 
Gray Canyons, Black Rocks, Westwater Canyon, and Cataract Canyon), with 
one additional extirpated population (Dinosaur National Monument). The 
Upper Basin Recovery Program's conservation and management actions have 
maintained and improved resource conditions for humpback chub 
populations in the upper basin over the last 15 years. The Westwater 
Canyon population has increased substantially over the past 5 years 
(Hines et al. 2020, pp. 10, 28, 32), and the Black Rocks populations 
has remained stable (Francis et al. 2021, pp. 36-38). The best 
available information indicates that the Desolation and Gray Canyons, 
and Cataract Canyon populations are also stable (Ahrens 2019, pp. 2, 7; 
Caldwell 2021, p. 17). Currently, management actions in the upper basin 
have improved river flows such that habitats are suitable to support 
humpback chub populations. Although nonnative predatory fish species 
that prey on humpback chub, such as northern pike (Esox lucius), 
walleye (Sander vitreus), and smallmouth bass (Micropterus dolomieu), 
have been documented near multiple humpback chub populations, the upper 
basin populations are largely free of these predators. Below, we 
summarize the condition of humpback chub habitats and populations in 
the upper basin, with additional detail provided in the SSA report 
(Service 2018b, pp. 34-124).
    In the upper basin, the four extant populations (Desolation and 
Gray Canyons, Black Rocks, Westwater Canyon, and Cataract Canyon) and 
one extirpated population (Dinosaur National Monument) currently have 
high-quality rocky canyon habitat, an adequate food base, and unimpeded 
connectivity (Service 2018b, pp. 83-85). Federal, State, and Tribal 
land ownership largely protects the humpback chub's canyon habitats in 
the upper basin, and recreation is the primary activity in these 
canyons. Water temperature is suitable and unaltered by reservoir 
releases in the upper basin, except for a portion of the extirpated 
Dinosaur National Monument population in the Green River that is cooled 
by releases from the Flaming Gorge Dam. Fish passage structures ensure 
movement can occur between the populations in the upper basin (Service 
2018b, pp. 83-85).
    The stressors of highest concern to the humpback chub in the upper 
basin are reduced river flows and predatory, nonnative fish. Over the 
last 50 years, the operation of large, Federal dams altered river flows 
and temperature regimes of upper basin rivers by reducing spring peak 
flows and increasing summer and winter base flows, conditions generally 
unsuitable for humpback chub. Additionally, large municipal and 
agricultural water withdrawals during the 20th century reduced the 
amount of water in the upper basin rivers. Water withdrawals have 
remained relatively stable over approximately the last 20 years 
(Colorado Water Conservation Board 2019, p. 1; 2020 p. 1; Wyoming Solar 
Energy Association 2019, p. 3), while severe and persistent drought has 
reduced water supply in the upper basin since 2000 (Udall and Overpeck 
2017, p. 2406; Williams et al. 2020, p. 315). Climatic warming and 
increased evapotranspiration have exacerbated declines in precipitation 
since 2000 (Milly and Dunne 2020, pp. 1252-1254; Williams et al. 2020, 
pp. 314-317), resulting in reduced water availability to the upper 
basin rivers (Udall and Overpeck 2017, pp. 2404-2406) used by the 
humpback chub.
    The humpback chub evolved in an environment relatively free of 
predators and competitors, so the species is ill-adapted to live with 
the many nonnative fish that have been introduced into the

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Colorado River basin. The humpback chub is a soft-rayed fish with no 
defense mechanisms to protect itself from nonnative predatory fish 
species. Over 50 nonnative fish species have been introduced into the 
upper basin, some of which prey on or compete with young humpback chub, 
thereby reducing survival rates of juvenile humpback chub. Smallmouth 
bass present the largest predatory threat to native fish in the upper 
basin (Johnson et al. 2008, p. 1946), but northern pike and walleye are 
also problematic nonnative predators. Humpback chub are at most risk 
from predation if nonnative predators colonize their canyon habitats, 
which may result in severe, localized predation on young humpback chub. 
Nonnative predators can also emigrate from nearby source populations 
and exert predatory pressure on humpback chub populations. Adult 
northern pike and walleye migrate through upper basin humpback chub 
populations in low densities, but do not yet reside and reproduce in 
any population. Nearby populations of smallmouth bass have not 
colonized Black Rocks, Westwater Canyon, or Cataract Canyon, but have 
been collected there in low densities. Smallmouth bass inhabit and 
reproduce in Dinosaur National Monument and Desolation and Gray 
Canyons, and periodically increase in density in response to low river 
flows and warm water temperatures that promote their reproduction and 
growth. Although a concern, nonnative predators occur in low densities 
in humpback chub habitats in the upper basin but have not colonized 
these habitats.
    The Upper Basin Recovery Program oversees management actions needed 
to improve conditions for the humpback chub in the upper basin. Over 
the past 15 years, the Upper Basin Recovery Program has implemented a 
large suite of actions to improve the resources of highest concern for 
humpback chub, including, but not limited to: providing and protecting 
river flows; managing and removing predatory, nonnative fish; and 
installing and operating fish passage structures.
    Despite the severe drought experienced in the upper basin over the 
past 15 to 20 years, management of river flows has restored much of the 
important intra- and inter-annual variability of river flow that the 
humpback chub needs to breed, feed, and shelter. Changes in the 
operation of large Federal dams and provision of water dedicated to 
environmental flows have managed flows to benefit the humpback chub. 
Despite a severe reduction in water availability due to drought since 
2000, water managers have provided flow regimes in upper basin rivers 
that support humpback chub. For example, both Flaming Gorge Dam (the 
Green River) and the Aspinall Unit (the Colorado River) changed 
operational release patterns in 2006 and 2012, respectively, to reduce 
adverse effects of altered flow regimes and to provide downstream flows 
to benefit the humpback chub and other fish species (Service 2018b, p. 
39). Operational release patterns at Flaming Gorge Dam, implemented 
since 2006, have been evaluated for their effectiveness, and revised 
flow recommendations have been drafted to further improve river flow 
conditions for humpback chub and other fish species (LaGory et al. 
2019, pp. 4-24, 5-6, 5-20-5-32). Implementing, evaluating, and revising 
flow recommendations demonstrates a commitment by stakeholders to 
provide flow regimes that benefit the humpback chub.
    To maintain flows, the Upper Basin Recovery Program acquired water 
stored in reservoirs in the Yampa and Colorado Rivers and releases this 
water to support the humpback chub when needed, such as during low-flow 
periods during the summer (Service 2018b, p. 39). Stakeholders in the 
Upper Basin Recovery Program implement various other actions to improve 
flow conditions for humpback chub, such as voluntary releases of water 
to augment the spring peak on the Colorado River mainstem (Coordinated 
Reservoir Operations), which has occurred 12 times since 1997 (Service 
2018b, p. 39). Furthermore, the Colorado Water Conservation Board holds 
instream flow water rights on two reaches of the Colorado River to 
maintain minimum flows in the river, which may benefit downstream 
habitats and designated critical habitat for humpback chub.
    In the upper basin, the Upper Basin Recovery Program also 
implements a comprehensive suite of nonnative fish management actions 
to limit predation by nonnative fish species (Service 2018b, p. 90). 
The two core actions to reduce predation of humpback chub are removing 
predatory fish from approximately 966 km (600 mi) of river and 
screening reservoirs to prevent predators from escaping into the 
downstream habitats used by humpback chub. Additionally, State partners 
in the Upper Basin Recovery Program no longer stock certain nonnative 
predators, and instead stock fish species that are more compatible with 
the recovery of humpback chub, such as sterile individuals that will 
not establish populations in river habitats. State partners also have 
implemented harvest regulations that promote the removal of nonnative 
predatory fish throughout the upper basin, including sponsoring 
incentivized harvest in some locations.
    Over the last 20 years, partners have installed five fish passage 
structures in the Colorado, Gunnison, and Green Rivers to provide 
ecological connectivity between the upper basin populations. Fish 
passages built by the Upper Basin Recovery Program partners allow 
humpback chub in all four extant upper basin populations to emigrate to 
any of the other three extant populations and the extirpated Dinosaur 
National Monument population. Unimpeded movement between all upper 
basin populations provided by the fish passage structures allows for 
genetic exchange and maintenance of genetic diversity of populations.
    Upper basin populations have been monitored using catch per unit 
effort (CPUE) protocols since the mid-1980s, but more rigorous mark-
recapture population estimation techniques began in some humpback chub 
populations in the late 1990s. Abundance estimates generally have some 
uncertainty, with wide confidence intervals in older estimates and more 
precision in recent estimates. Despite the uncertainty associated with 
population monitoring techniques, these abundance estimates and 
associated CPUE data provide important demographic information about 
humpback chub populations.
    The Black Rocks and Westwater Canyon populations both declined from 
around year 2000, when they were first estimated, through about 2006, 
after which they both stabilized through about 2012 (Service 2018b, p. 
101). The most recent preliminary estimates of the Black Rocks 
population, for years 2016 and 2017, indicate continued stabilization 
of the population at around 430 adults (Francis et al. 2021, pp. 36-
38). A large group of juvenile humpback chub documented in 2017 may 
increase the size of the Black Rocks population in future years 
(Francis et al. 2021, pp. 36, 38). The most recent estimates of the 
Westwater Canyon population, for years 2016 and 2017, indicate the 
population increased substantially to around 3,300 adults (Hines et al. 
2020, pp. 10, 28, 32), likely the result of several years of 
recruitment since 2015. For the last 19 years, adult survival for 
humpback chub in Black Rocks and Westwater Canyon was relatively stable 
around 75 percent (Hines et al. 2020, pp. 10, 33; Francis et al. 2021, 
pp. 39-40). Emigration of humpback chub between Black Rocks and 
Westwater Canyon demonstrate connectivity, with approximately 2 percent 
of each population emigrating to the other population each year, for a 
net

[[Page 57593]]

contribution of approximately 50 individuals a year to the Black Rocks 
population (Hines et al. 2020, p. 17; Francis et al. 2021, p. 41).
    Adult abundance trends in Desolation and Gray Canyons are generally 
similar to those for Westwater and Black Rocks because they were 
highest around year 2000 and subsequently declined through about 2006 
(Service 2018b, p. 101). However, estimates from 2001 to 2003 have low 
precision and did not employ the same sampling regime as subsequent 
sampling. Since 2003, when standardized sampling began, preliminary 
analysis of long-term demographic metrics, catch rates, and site-
specific abundance estimates indicate that the Desolation and Gray 
Canyons humpback chub population is stable (Caldwell 2021, p. 17). 
Specifically, canyon-wide catch rates of adults and the proportion of 
first year adults have remained consistent (Caldwell 2021, pp. 17, 27-
31). Using estimates from 2006 to 2019, the adult abundance trends for 
long-term monitoring sites in Desolation and Gray Canyons are stable or 
increasing (Caldwell 2021, pp. 17, 32-33). Results from standardized, 
long-term monitoring in 2018 and 2019 demonstrates that the Desolation 
and Gray Canyons population is likely stable.
    The Cataract Canyon population is small, with fewer than 500 
adults. Swift currents make this population difficult to monitor. 
Abundance of humpback chub in Cataract Canyon is estimated by CPUE 
rather than more robust mark-recapture techniques, which makes 
estimating a population trend for Cataract Canyon difficult. Monitoring 
efforts from 2017 documented the highest annual CPUE for humpback chub 
in Cataract Canyon over the last 26 years (Ahrens 2017, p. 7), and the 
CPUE measured in 2019 was also above average (Ahrens 2019, pp. 2, 10). 
Analysis of CPUE by year since the 1990s demonstrates the population is 
stable, as the CPUE for humpback chub in Cataract Canyon has been 
increasing, but not in a statistically significant manner (Ahrens 2019, 
pp. 2, 7). Additionally, new sampling techniques in 2017 and 2019 
increased the ability to document the presence of juvenile humpback 
chub in Cataract Canyon (Ahrens 2017, p. 2; Ahrens 2019, p. 3).
    Unlike the other four populations in the upper basin, the Dinosaur 
National Monument population is currently below detection limits for 
humpback chub and is now considered functionally extirpated. By 1998, 
humpback chub in Dinosaur National Monument were absent or rare in 
habitats where the species was likely common in the 1940s (Tyus 1998, 
p. 192). The last collections of humpback chub in this population were 
in the Yampa River in 2004 (Service 2018b, p. 114) and in the Green 
River in 2006 (Bestgen and Irving 2006, p. 2). The decline of the 
humpback chub population in Dinosaur National Monument likely started 
with the treatment of the Green River with rotenone (a chemical used to 
kill fish) following the completion of Flaming Gorge Dam in 1962 
(Service 2018b, p. 81). Starting in 1963, any remaining humpback chub 
in the Green River portion of the Dinosaur National Monument population 
were negatively affected for decades by the cold, stable releases from 
Flaming Gorge Dam. Since 2006, operational changes at Flaming Gorge Dam 
have improved the water temperature and flow conditions in the Green 
River so that they could be more suitable for humpback chub. These 
operational flow regimes at Flaming Gorge Dam have been evaluated and 
could be revised to further reduce impacts on humpback chub and other 
native fish species (LaGory et al. 2019, pp. 4-24, 5-6, 5-20-5-32).
    Flows in the Yampa River portion of the Dinosaur National Monument 
population are largely unregulated, but the Yampa River has experienced 
large-scale water withdrawals and low river flows, especially in the 
early 2000s. The extreme low flows in 2002 likely resulted in the 
extirpation of the remaining humpback chub in the Yampa River and 
allowed smallmouth bass to proliferate throughout the upstream reaches. 
Since 2007, water acquired by the Upper Basin Recovery Program and 
released from Elkhead Reservoir has supported improved flow conditions 
in the Yampa River (Service 2018b, p. 39), but smallmouth bass continue 
to dominate the Yampa River upstream of humpback chub habitats.
    Dinosaur National Monument may now have suitable resource 
conditions to support a reestablishment effort of humpback chub. The 
rocky canyon habitats preferred by the humpback chub are still present 
in Dinosaur National Monument, and the native fish community is largely 
intact. Although management actions have improved resource conditions 
in Dinosaur National Monument, immigration from other humpback chub 
populations is too low for the species to recolonize naturally, and the 
population is considered extirpated. Because habitats could potentially 
support a population, the Upper Basin Recovery Program has convened a 
team to consider translocation or stocking to restore the humpback chub 
to the Dinosaur National Monument population.
    Summary of Current Conditions in the Lower Basin--The lower basin 
has one large population of humpback chub located in the Grand Canyon. 
Resource conditions in the lower basin are of sufficient quality and 
quantity to support population resiliency. Humpback chub are 
reproducing in many of these broadly distributed areas, demonstrating 
that the species can complete its entire life history in multiple, 
diverse locations within the Grand Canyon in the lower basin. Below, we 
summarize current conditions for humpback chub in the lower basin, with 
additional detail provided in the SSA report (Service 2018b, pp. 34-
124).
    Although the Grand Canyon population is the only humpback chub 
population in the lower basin, the population is large and includes: A 
core population area in the Little Colorado River and nearby mainstem 
Colorado River; a recent range expansion into western Grand Canyon; and 
individuals translocated into tributary habitats in Havasu Creek and 
the upper Little Colorado River. The Grand Canyon population has high-
quality canyon reaches that provide unimpeded connectivity between its 
habitats. In this population, there are no barriers to movement, except 
for those created by natural falls or chutes in tributary habitats. 
Translocated humpback chub placed above these natural barriers helped 
improve redundancy of humpback chub populations in the lower basin. 
Landownership surrounding the Grand Canyon population is Federal and 
Tribal, so human access and use are well-regulated.
    The stressors of highest concern to humpback chub in the lower 
basin are altered river flows, reduced water temperature, inadequate 
food supply, and predatory nonnative fish. Releases from the Glen 
Canyon Dam alter the flow and temperature regimes of the Colorado River 
throughout much of the Grand Canyon population by reducing spring 
peaks, increasing base flows, and cooling the river through much of the 
year. Despite flow and temperature changes, humpback chub continue to 
use the mainstem near the mouth of the Little Colorado River for all 
life stages, except spawning, egg incubation, and larval development, 
which occur primarily in the Little Colorado River (Service 2018b, p. 
59). Furthermore, the species has recently expanded into the western 
Grand Canyon (Van Haverbeke et al. 2017; Rogowski et al. 2018, p. 26) 
as the elevation of Lake Mead has

[[Page 57594]]

receded, possibly the result of warmer water temperatures in the 
mainstem portion of the river (Van Haverbeke et al. 2017, p. 285).
    The Long-Term Experimental and Management Plan prescribes the 
release patterns from the Glen Canyon Dam, helping to reduce and 
minimize impacts to humpback chub habitats in the Grand Canyon (U.S. 
Department of the Interior (DOI) 2016, pp. 1-2). Starting in 2004, the 
temperature of water released through the Glen Canyon Dam increased in 
the summer and fall periods to 16 degrees Celsius ([deg]C) (61 degrees 
Fahrenheit ([deg]F)). Warmer temperatures generally allow individual 
humpback chub to grow larger and more quickly, but warmer water may 
also allow predatory, nonnative fish to invade and expand into humpback 
chub habitats.
    Predatory nonnative fish in the lower basin include warm-water 
species that have escaped from Lake Powell and cold water salmonids 
such as brown trout (Salmo trutta) and rainbow trout (Oncorhynchus 
mykiss) that prey on juvenile humpback chub in the cold tailwaters of 
Glen Canyon Dam (Ward and Morton-Starner 2015, p. 1184). Although these 
two predators overlap with humpback chub in portions of the mainstem 
Colorado River, the predators are concentrated in the colder water 
immediately below Glen Canyon Dam and tributaries of the Colorado River 
in the Grand Canyon, so are not distributed fully throughout humpback 
chub habitats in the lower basin. The majority of the areas inhabited 
by humpback chub, including the Little Colorado River and western Grand 
Canyon, are dominated by native fish (Pillow et al. 2018, p. 7; Stone 
et al. 2018, p. 119; Van Haverbeke et al. 2019, p. 8; Kegerries et al. 
2020, p. 146; Van Haverbeke et al. 2020, p. 8). Nonnative fish are 
likely limited by abiotic (physical) factors in the Little Colorado 
River, such as carbon dioxide and sediment regimes, which allows 
humpback chub and other native fish species to dominate this important 
habitat (Stone et al. 2018, p. 119). Similarly, turbidity could be 
limiting nonnative species in the western Grand Canyon allowing for 
humpback chub range expansion (Kegerries et al. 2020, pp. 152-154).
    In the lower basin, the Glen Canyon Dam AMP coordinates the 
protection of natural resources of the Colorado River flowing through 
the Grand Canyon, including the humpback chub, from Glen Canyon Dam to 
the Lake Mead inflow. Actions undertaken to support recovery of 
humpback chub include, but are not limited to: Management actions to 
reduce nonnative fish species; altering dam releases to study possible 
improvements of important food sources for humpback chub, such as 
mayflies, stoneflies, and caddisflies; and the translocation of 
humpback chub to new habitats.
    In the lower basin, management actions are geared toward the 
removal of both warm water and cold water nonnative fish species, but 
these actions do not occur unless predetermined conditions are met (DOI 
2016, pp. B-22-B-31; NPS 2018, pp. 7-26). Removal of nonnative trout 
occurs in locations managed for humpback chub, but, currently, removal 
of nonnative species in the lower basin occurs only in Bright Angel 
Creek. The National Park Service (NPS) has recently implemented an 
``Expanded Nonnative Species Management Plan'' to prevent, control, 
minimize, or eradicate potentially harmful nonnative aquatic species 
(NPS 2018, p. 1). Recent increases in the nonnative green sunfish 
(Lepomis cyanellus) and brown trout in the Glen Canyon reach have 
raised concerns about risks to humpback chub and have prompted NPS to 
consider additional tools and new approaches to control nonnative 
aquatic species (NPS 2018, pp. 1-3).
    In the lower basin, temperature, daily flow variation, and 
competition with other fish species influence the aquatic food base 
available to humpback chub, which may limit the size of the Grand 
Canyon population of humpback chub. Dam releases for hydropower 
production that match intra-daily electrical demand, a process known as 
``hydropeaking,'' could limit the availability of important 
macroinvertebrates eaten by humpback chub and other native fish 
species, by desiccating insect eggs that are laid during high water 
periods but then are exposed as flows recede (Miller et al. 2020, p. 
584). It is unclear if hydropeaking reduces the availability of aquatic 
insects for humpback chub in the Grand Canyon (Kennedy et al. 2016, p. 
1), so the Glen Canyon Dam AMP is testing a series of flows 
specifically to improve the production of macroinvertebrates. The 
experiments are ongoing and it is unclear if these production flows 
have increased long-term macroinvertebrate density (Kennedy and 
Meuhlbauer 2020, pp. 12-20) or improved condition of humpback chub.
    Since 2003, partners in the Glen Canyon Dam AMP have translocated 
humpback chub to tributaries of the Colorado River to establish 
population redundancy and introduce humpback chub to areas with low 
densities of nonnative fish. Humpback chub translocated upstream in the 
Little Colorado River above Chute Falls, a natural barrier to fish 
movement, demonstrated higher growth rates and earlier sexual maturity 
than those below the falls, and are also likely reproducing in the 
translocation area (Stone et al. 2020, p. 1). A 3-year effort to 
introduce humpback chub into Shinumo Creek in the lower basin indicated 
that the tributary provided favorable conditions for growth and 
survival despite high emigration rates (Spurgeon et al. 2015, p. 502), 
but a 2014 fire and subsequent flooding extirpated humpback chub from 
the area (Healy et al. 2020a, p. 9). A later effort in Havasu Creek 
found that translocated individuals survived and grew at rates that 
matched the Little Colorado River core population, and these 
individuals potentially established a self-sustaining population (Healy 
et al. 2020a, pp. 1-2). In addition, humpback chub were translocated 
into Bright Angel Creek in 2018 and 2020, and evaluation is underway 
(Healy et al. 2020b, pp. 3-5). These efforts indicate that humpback 
chub tolerates translocation for conservation, which may be an 
important tool to its recovery in the future.
    The lower basin's Grand Canyon population of humpback chub is the 
largest and most extensively distributed population of all the 
populations across the species' range, with broadly distributed groups 
of humpback chub in mainstem and tributary habitats between Glen Canyon 
Dam and Lake Mead. The core area includes the Little Colorado River and 
nearby portions of the mainstem Colorado River. A substantial 
population decline occurred in the Little Colorado River during the 
1990s, followed by a strong increase around 2007 (Van Haverbeke et al. 
2019, pp. 21, 41). This core group remained relatively stable from 2008 
to 2014, with a high abundance of approximately 11,500 to 12,000 adults 
(Service 2018b, pp. 117-119; Van Haverbeke et al. 2019, p. 41). 
Significantly lower abundance estimates in 2015 and 2016 likely 
resulted from humpback chub remaining in the mainstem Colorado River 
(Van Haverbeke et al. 2019, p. 25), not a reduction in population size. 
Since 2017, spring adult and subadult abundances equal or exceed 
previous estimates (Van Haverbeke et al. 2019, pp. 8, 41-42), 
demonstrating this population continues to be large and stable. 
Increases in adult abundance after 2006 were likely due to increased 
recruitment corresponding with warmer temperatures of released water 
and reduced nonnative, predatory trout numbers near the confluence with 
the Little Colorado River.

[[Page 57595]]

    In addition to the core population in and near the Little Colorado 
River, the Grand Canyon population also has multiple aggregations of 
adult and subadult humpback chub distributed in the mainstem Colorado 
River. Humpback chub catch rates within these aggregations have 
increased significantly since 2010, especially in western Grand Canyon 
(Van Haverbeke et al. 2020, pp. 9, 31). In fact, relatively large 
numbers of humpback chub in the western Grand Canyon, including age-0 
individuals (life stage after larvae, within the first year of life), 
downstream of Diamond Creek indicate the likelihood of a new 
subpopulation (Van Haverbeke et al. 2017, pp. 285, 288-289; Rogoswki et 
al. 2018, pp. 26, 33-34). Length frequencies for the humpback chub in 
western Grand Canyon indicate local, natural recruitment (Van Haverbeke 
et al. 2017, p. 288; Rogoswki et al. 2018, p. 34). Evidence of 
reproduction and recruitment that does not appear to be reliant on the 
Little Colorado River indicates that the western Grand Canyon is likely 
a second, subpopulation in the lower basin, which would improve 
redundancy in the lower basin.
    Lastly, translocation efforts are potentially establishing a third, 
smaller subpopulation in Havasu Creek. Beginning in 2016, natural 
recruitment to sexual maturity of humpback chub that were produced in 
Havasu Creek occurred simultaneously with increases in abundance for 
this population (Healy et al. 2020a, pp. 2, 8). Although the Havasu 
Creek population is still new and its long-term success is not 
guaranteed, it provides additional redundancy to the Grand Canyon 
population, the lower basin, and the species.
    Summary of Species' Current Condition--The humpback chub has many 
traits that enable individuals to be resilient in the face of 
environmental or demographic stochasticity, including a long life span, 
high reproductive potential, use of habitats and water quality that are 
arduous to other fish species, adaptation to a wide variety of flow and 
thermal regimes, and a variable omnivorous diet. Population resiliency 
is demonstrated by the stability of small populations (Cataract 
Canyon), population increases after previous declines (Grand Canyon and 
Westwater Canyon), population establishment after translocations 
(Havasu Creek), expansion into new areas (western Grand Canyon), and 
stabilization after previous declines (Black Rocks). In addition, the 
large population size of the Little Colorado River portion of the Grand 
Canyon population in the lower basin reduces risk from stressor and 
environmental stochasticity. Similarly, the large Westwater Canyon 
population supports a strong core population in the upper basin.
    The current distribution of the humpback chub in five extant 
populations across the upper and lower basins, with new populations 
emerging in the lower basin, provides redundancy for the humpback chub 
and reduces catastrophic risk. The distribution of the four extant 
populations in the upper basin across different river basins and many 
miles of rivers also reduces catastrophic risk. Black Rocks and 
Westwater Canyon are the only two populations that are in relatively 
close proximity. In the lower basin, the single humpback chub 
population is large and widespread, a distribution that provides 
redundancy and reduces catastrophic risk to the species. In the lower 
basin, humpback chub may be expanding their range into western Grand 
Canyon and reproducing in newly established locations, such as Havasu 
Creek, which may also provide redundancy to the large Little Colorado 
River core area.
    Humpback chub populations also have adequate representation, as the 
multiple populations distributed across the range support the species' 
genetic diversity. The species' genetic diversity has not declined over 
the past decade (Bohn et al. 2019, p. 25). Upper basin populations are 
generally more diverse than the lower basin population, demonstrating 
adequate exchange of individuals between populations in the upper basin 
(Bohn et al. 2019, pp. 8, 24-25). Recent analysis recommends that 
genetic diversity of the species be managed as three units: Upper 
Colorado River (Cataract Canyon, Black Rocks, and Westwater Canyon), 
Green River (Desolation and Gray Canyons), and the Lower Basin (Grand 
Canyon and tributaries) (Bohn et al. 2019, p. 8).
    Summary of Future Conditions--In our SSA report, we evaluated 
future conditions for the humpback chub using projections for the 
stressors, habitat factors, and demographic factors that influence its 
resiliency, redundancy, and representation (Service 2018b, pp. 125-
153). For this species status assessment, we defined viability as the 
ability of the species to sustain populations in natural ecosystems 
over a biologically meaningful timeframe, in this case, 16 and 40 years 
into the future. These timeframes are periods that allow us to 
reasonably project the potential effects of various stressors within 
the range of the species and account for multiple generations of the 
humpback chub. These projections are consistent with the time scale for 
which we have data available on the species and its stressors. We 
projected the resiliency, redundancy, and representation of the 
humpback chub under three plausible future scenarios, both 16 and 40 
years into the future. We developed future scenarios to help capture 
uncertainty associated with the future and describe the range of 
plausible future conditions within the overall range of the humpback 
chub. Below, we summarize the three future scenarios that we used to 
evaluate a range of plausible future conditions for the humpback chub, 
which are discussed in greater detail in our SSA report (Service 2018b, 
pp. 134-135).
    Future Scenario 1 describes a reduction or elimination in current 
voluntary management actions for the species, but recognizes that 
conservation actions established under binding operational plans and 
agreements would continue; as such, Scenario 1 describes a plausible 
future with reduced conservation actions. Future Scenarios 2 and 3 
include the established management actions undertaken in Scenario 1, 
along with currently implemented voluntary management actions, and 
additional proactive and adaptive management actions that may be needed 
in the future; both Scenarios 2 and 3 are plausible futures with 
continued commitment to conservation actions. Scenarios 2 and 3 differ 
in their confidence in the effectiveness of the conservation actions: 
Scenario 2 considers that implemented actions are not fully effective 
to mitigate impacts of drought, future water development, nonnative 
fishes, or other threats, whereas Scenario 3 considers that implemented 
actions are sufficient to mitigate impacts of drought, future water 
development, nonnative fishes, and other threats. Scenarios 2 and 3 
were developed to recognize the uncertainty concerning management 
actions' ability to mitigate stressors impacting humpback chub, 
especially future water availability and nonnative fish.
    Under Scenario 1, conditions would severely degrade within both 16 
and 40 years, primarily in the upper basin because collaborative 
partnerships would be eliminated or reduced. However, if collaborative 
partnerships remain in place and their conservation actions are 
effective as described under Scenario 3, resource conditions improve at 
16- and 40-year timeframes. Under Scenario 2, degradation of resources 
takes place, even as conservation actions continue, resulting in 
neutral conditions within 16 years, but poor

[[Page 57596]]

conditions within 40 years. Although there is high uncertainty 
regarding resource conditions under Scenario 2 at 40 years, 
extrapolation of the expected resource conditions from 2034 onward 
demonstrates a continuing decline in resource conditions. The potential 
extirpation of multiple populations could most likely occur in the 
upper basin under the short 16-year timeframe in Scenario 1 and the 
longer 40-year timeframe under Scenario 2. Under Scenario 3, ongoing 
threat management proves successful in the long term, improving 
resource conditions. The health (resiliency) and distribution 
(redundancy) of all five extant populations reduces the risk from a 
potential catastrophic event under Scenario 3.
    Scenarios 1 and 2 projected that within 40 years the populations 
and overall viability of humpback chub would be at increased risk and 
could decline (Service 2018b, pp. 159-163). Future conditions for 
humpback chub would only improve under Scenario 3 if long-term 
management actions are successful. The SSA report contains a more 
detailed discussion of our evaluation of the biological status of the 
humpback chub and the influences that may affect its continued 
existence (Service 2018b, pp. 154-163).
    New Scientific Information--New scientific and commercial data 
completed after the SSA report (Service 2018b, entire) helps improve 
our understanding of the humpback chub and the management actions 
needed to conserve the species. We included this new information above 
in our summary of current conditions for both the upper and lower 
basins. Since 2018, new monitoring data indicates that all four extant 
upper basin populations are likely stable or increasing, reducing the 
uncertainty of the trajectory of these populations. In the lower basin, 
monitoring indicates that the Little Colorado River core area is 
stable, that humpback chub have expanded their range into western Grand 
Canyon, and that a translocated population in Havasu Creek is naturally 
recruiting. Population demographics for all extant populations of the 
species indicates that management actions enacted recently, such as 
operational flow regimes from dams and nonnative fish removal, are 
assisting the species. This information increases support for Scenario 
3, as continued management actions in both basins are resulting in 
improved population resiliency across the current range of the species.
    To date, the Upper Basin Recovery Program has not been formally 
extended and is scheduled to expire in 2023, so Scenario 1 in the SSA 
report (2018b, entire), with its reduction of conservation efforts, 
remains plausible. Partners are committed to implementing recovery 
actions after 2023, as demonstrated by their ongoing negotiations to 
define the future of the partnership. However, until the structure and 
funding for this partnership is defined, the analysis of future 
conditions under Scenario 1 as presented in the SSA report (Service 
2018b, entire) remains unchanged.
    The purpose of the SSA was to characterize the current and future 
viability of the humpback chub in terms of the 3Rs, considering the 
potential current and future effects of stressors. In our SSA report, 
we described the current condition and three plausible future 
conditions for the humpback chub in terms of its resiliency, 
redundancy, and representation (Service 2018b, entire).
    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 of stressors on individuals, 
populations, and 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 condition of the 
species across the upper and lower basins and five populations. Our 
assessment of the current and future conditions encompasses and 
incorporates the threats individually and cumulatively (Service 2018b, 
entire). Our current and future condition assessment is iterative 
because it accumulates and evaluates the effects of all the factors 
that may be influencing the species, including negative influences from 
stressors and positive influences from conservation efforts. We 
evaluate potential effects from these influences consistently across 
the same subset of habitat and demographic needs for the species, both 
currently and into the future. Because the SSA framework considers not 
just the presence of the factors, but also 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.
    In our determination, we correlate the threats acting on the 
species to the factors in section 4(a)(1) of the Act. We summarize the 
status assessment for the humpback chub below.
    The biological information we reviewed and analyzed as the basis 
for our findings is documented in the SSA report (Service 2018b, 
entire), a summary of which is provided above. The projections for the 
future condition of the species are based on our expectations of the 
potential stressors that may affect the humpback chub. The potential 
stressors we evaluated in detail in the SSA report (Service 2018b, 
entire) that fall under Factors A, B, C, and E of the Act are: River 
flows (Factor A) and predatory nonnative fish (Factor C) in the upper 
basin populations; and river flows (Factor A), water temperature 
(Factor A), food supply (Factor A), and predatory nonnative fish 
(Factor C) in the lower basin population (Service 2018b, pp. 34-100). 
Existing regulatory mechanisms (Factor D) are discussed below.
    Some stressors, such as low river flows and warm water 
temperatures, may also act cumulatively to increase the impact of 
predatory nonnative fish. Certain needs or stressors require continued 
management, such as river flow and nonnative fish in all five extant 
populations, and water temperature and food supply in the Grand Canyon 
population. Ongoing management actions are primarily undertaken by two 
multi-stakeholder management programs, the Upper Colorado River 
Endangered Fish Recovery Program (Upper Basin Recovery Program) and the 
Glen Canyon Dam Adaptive Management Program (Glen Canyon Dam AMP).
    Our analysis found that the primary drivers for the humpback chub's 
current and future condition are diminishing river flow (Factor A), 
increasing water temperature (Factor A), expanding populations of 
nonnative fish (Factor C), and food availability in the Grand Canyon 
(Factor A). Low river flows and warm water temperatures may also act 
cumulatively to increase predation by nonnative predators. We summarize 
these stressors below, with more detail provided in the SSA report 
(Service 2018b, pp. 126-133).
    River flow and temperature--The presence and operation of large 
dams alters suitable river flow and temperatures. Historically, dam 
operations did not always provide river flow conditions that supported 
humpback chub, but recent modifications to operations have reduced some 
impacts from the presence of dams. In the upper basin, modifications 
including restoring much of the important intra- and inter-annual 
variability of river flow have helped improve conditions for the 
humpback chub. Revised operational regimes are subsequently monitored, 
evaluated, and revised for their effectiveness to improve conditions 
for the humpback

[[Page 57597]]

chub (LaGory et al. 2019, pp. 4-24, 5-6, 5-20-5-32).
    We also evaluated how the effects of climate change could impact 
river flows and water temperatures by using hydroclimate projections of 
future water resources in the Colorado River basin. Hydroclimate 
projections predict that decreased warm-season runoff will reduce water 
supply, primarily from increased frequency and severity of drought, 
which will further result in warmer water temperatures (U.S. Bureau of 
Reclamation 2016, pp. i-ii). Climatic warming and increased 
evapotranspiration are expected to exacerbate a decline in water supply 
beyond declines in precipitation (Udall and Overpeck 2017, pp. 2404-
2406; Milly and Dunne 2020, pp. 1252-1254; Williams et al. 2020, pp. 
314-317). Warmer, lower flows in the upper basin increase the risk of 
nonnative fish species impacting humpback chub populations by 
supporting the growth and reproduction of smallmouth bass. Warmer 
releases from Lake Powell could also impact abundance and distribution 
of nonnative fish in the Grand Canyon.
    Currently, river flow conditions and temperatures are largely 
adequate for humpback chub in both the upper and lower basins because 
reservoir managers have exercised flexibility in their operations to 
support humpback chub while meeting downstream delivery obligations. 
Furthermore, current river flow conditions have supported native fish 
strongholds in humpback chub habitats despite nearby populations of 
predatory nonnative fish. Future river flow and temperature conditions 
are uncertain because regional climatic patterns predict reduction in 
water availability that may exceed the ability of operational 
flexibility to provide adequate flows.
    Food availability--Humpback chub require an adequate and reliable 
food supply, which can consist of a variety of insects, crustaceans, 
and plants. Food is supplied by the instream production of 
invertebrates, insect emergences, and floods laden with debris. In the 
upper basin, although food supply has not been measured, it is not 
estimated to be a limiting factor. Conversely, below Glen Canyon Dam in 
the lower basin, the condition of the humpback chub populations is 
hypothesized to be impacted by low aquatic insect diversity and stream 
productivity. To improve egg-laying conditions for aquatic insects, the 
primary food source for the humpback chub in the Colorado River, the 
Glen Canyon Dam AMP is conducting experiments to evaluate densities of 
macroinvertebrates under various flow regimes (Kennedy and Meuhlbauer 
2020, pp. 12-20) to see if they will appreciably improve humpback chub 
condition. Therefore, low food availability could be a stressor to the 
species in the lower basin.
    Predation--Predation and competition by nonnative fish are 
stressors to humpback chub in both the upper and lower basins. Juvenile 
humpback chub are vulnerable to predation from predatory, nonnative 
fish during the first few years of life. Nonnative fish can also 
compete for resources with adult humpback chub, reducing the ability of 
the humpback chub to breed, feed, and shelter. Although the humpback 
chub has no natural defense mechanism to protect itself from nonnative 
predators, the more arduous hydrological conditions of the humpback 
chub's canyon habitats are less favorable to the nonnative predators, 
which may limit the effects of nonnative fish. However, predation from 
nonnative fish may also increase when warm water temperatures act 
cumulatively with low flows.
    In the upper basin, predation and competition by nonnative fish, 
particularly smallmouth bass, walleye, and northern pike, are potential 
threats to the viability of humpback chub. All upper basin humpback 
chub populations have dense nonnative predator populations nearby and 
experience predation pressure when adult predators emigrate. However, 
only the extant Desolation and Gray Canyons and the extirpated Dinosaur 
National Monument experience localized reproduction of smallmouth bass. 
Smallmouth bass colonization of multiple humpback chub populations 
would significantly decrease the viability of the species in the upper 
basin, but this has not yet occurred. In-river removal of nonnative 
predators focused on disrupting spawning successfully reduces adult 
densities of northern pike (Bestgen et al. 2020, pp. 11-12) and 
smallmouth bass (Hawkins 2019, pp. 12, 23) in certain reaches of the 
upper basin, but environmental conditions conducive to reproduction can 
produce strong year classes of young fish. This demonstrates that long-
term commitment to nonnative predator control can improve conditions 
for the humpback chub and other native fish, but must be performed 
consistently in order to control nonnative fish populations. 
Commitments to multifaceted management of nonnative fish has reduced 
the threat posed by nonnative predators in the upper basin, but if 
management actions decrease, the threat would likely increase.
    In the lower basin, current densities of nonnative predators are 
low in areas inhabited by humpback chub, such as the Little Colorado 
River and western Grand Canyon, likely because of abiotic factors, such 
as turbidity, water chemistry, and temperature (Pillow et al. 2018, p. 
7; Van Haverbeke et al. 2019, p. 8; Kegerries et al. 2020, p. 146). 
Management actions in place to prevent and respond to establishment of 
new species, including the NPS ``Expanded Nonnative Species Management 
Plan,'' provides additional tools and new approaches for controlling 
nonnative aquatic species (NPS 2018, pp. 1-3). Recent increases in 
brown trout density in the Lees Ferry reach of the Colorado River and 
the discovery of green sunfish immediately below Glen Canyon Dam 
demonstrate that risks do exist in the lower basin, but these risks are 
currently upstream of humpback chub habitats. Lower elevations of Lake 
Powell enhance risk of warm water nonnative predator establishment in 
the Grand Canyon via increased risk of fish escaping through Glen 
Canyon Dam and warmer water releases that support nonnative predators.
    Currently, nonnative fish moderately impact two (one extant and one 
extirpated) populations of humpback chub, while the remaining four 
extant populations are not currently being impacted. The threat of 
nonnative fish is being managed in the upper basin through multifaceted 
management actions, including but not limited to in-river nonnative 
predator removal, active flow management, and reservoir containment. In 
the lower basin, abiotic conditions currently limit the threat of 
nonnative fish. There remains risk for future increases in impacts from 
nonnative fish caused by altered flow conditions, but the magnitude of 
these impacts is uncertain. Therefore, nonnative predatory fish are not 
currently a threat to the species, but could become a threat in the 
future if management actions decrease.
    Regulatory mechanisms--Regulatory mechanisms (Factor D) and other 
management efforts benefit the humpback chub. Most resources affecting 
humpback chub are strictly regulated through Federal, State, and Tribal 
mechanisms. Humpback chub are considered a sensitive species in Utah 
(Utah Division of Wildlife Resources 2017, p. 2), a State threatened 
species in Colorado (Colorado Parks and Wildlife 2020, p. 3), a Tier 1 
vulnerable species in Arizona (Arizona Game and Fish 2019, p. 32), and 
an endangered species under Navajo Nation Code (Navajo Nation 2020, p. 
2), which provide various protections within those

[[Page 57598]]

boundaries. The humpback chub's canyon habitats are largely protected 
by Federal, State, and Tribal land ownership, and humans primarily use 
humpback chub habitats for recreation. Releases from large dams, 
primarily operated by the U.S. Bureau of Reclamation (USBR), are now 
operated to promote river function and fish habitat under binding 
operational and management plans described in the Records of Decision 
for the Aspinall Unit (USBR 2012, p. 1), Flaming Gorge Dam (USBR 2006, 
pp. 1-2), and Glen Canyon Dam (DOI 2016, pp. 1-2). In the upper basin, 
the Colorado Water Conservation Board holds instream flow water rights 
on two reaches of the Colorado River to maintain minimum flows in the 
river, which may benefit downstream-designated critical habitat for the 
humpback chub. Water use and delivery in the Colorado River basin is 
strictly regulated under existing Federal, State, and Tribal laws 
commonly referred to as the ``Law of the River,'' including, but not 
limited to, the Colorado River Compact of 1922, the Upper Colorado 
River Basin Compact of 1948, the Colorado River Storage Project Act of 
1956, the Colorado River Basin Project Act of 1968, and individual 
State and Tribal statutes that regulate water appropriation.
    The Upper Basin Recovery Program and Glen Canyon Dam AMP are key 
regulatory mechanisms that shape the current and future condition of 
humpback chub. These programs are considered regulatory mechanisms 
because they are authorized through, and comply with, Federal 
legislation and the Law of the River. The Upper Basin Recovery Program 
was authorized under Public Law 106-392 and has been renewed on a 
periodic basis by acts of Congress. The Glen Canyon Dam AMP was 
established under the Record of Decision to operate Glen Canyon Dam 
needed to comply with the Grand Canyon Protection Act of 1992 (USBR 
1996, pp. G-3-G-4), and funding for the program was authorized under 
Public Law 106-377. The Upper Basin Recovery Program coordinates and 
implements the majority of management actions in the upper basin, while 
the Glen Canyon Dam AMP undertakes management actions for the mainstem 
Colorado River in the lower basin. For example, both programs provide 
adequate habitat conditions by managing river flow and water 
temperature and by managing nonnative fish species. Conservation 
efforts implemented by the two programs over the past three decades 
demonstrate the success of these collaborative partnerships.
    The cooperative agreement implementing the Upper Basin Recovery 
Program was first signed in 1988, extended in 2001 and 2009, and is 
scheduled to expire in 2023. Expiration in 2023 creates uncertainty for 
continued implementation of conservation efforts. However, commitment 
to continue the decades-long partnership is strong, as demonstrated by 
ongoing efforts to extend the partnership beyond 2023. Language in 
Public Law 116-9 requires program stakeholders to work with the 
Secretary of the Interior to develop a list of actions necessary to 
assist in the recovery of the endangered fishes in the upper basin, and 
to estimate the costs of those actions. The partners are actively 
working to provide this information and to simultaneously define a 
program structure and funding strategy that would implement the actions 
after 2023. Partners recognize that declining hydropower production 
requires the negotiation of new funding strategies (Western Area Power 
Administration (WAPA) 2020, pp. 8-12, 16) and that funding must be 
adequate to implement the management actions necessary for humpback 
chub recovery in the upper basin. Until the Upper Basin Recovery 
Program partnership is defined and adequately funded, the humpback 
chub's future resource conditions are not certain because critical 
management actions, such as leasing water for river flows, in-river 
nonnative fish removal, fish passage operations, and monitoring may not 
be implemented.
    In the lower basin, the Long-Term Experimental and Management Plan 
and other legally binding mechanisms provide more certainty for 
humpback chub conservation actions, including additional adaptive 
actions likely needed to respond to changing resource conditions 
(Service 2018b, pp. 12-14). Unlike the Upper Basin Recovery Program, 
the Glen Canyon Dam AMP and associated funding does not have a 
scheduled expiration. However, declining hydropower production also 
impacts the funding strategies for this partnership (WAPA 2020, pp. 8-
12, 16). Continued implementation of management actions is critical to 
the humpback chub's future resource conditions in the lower basin.

Summary of Comments and Recommendations

    In the proposed rule published in the Federal Register on January 
22, 2020 (85 FR 3586), we requested that all interested parties submit 
written comments on our proposal to downlist the humpback chub by March 
23, 2020. We also contacted appropriate Federal and State agencies, 
Native American Tribes, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. 
Newspaper notices inviting general public comment were published in the 
Arizona Daily Sun (Arizona), the Salt Lake Tribune (Utah), and the 
Grand Junction Sentinel (Colorado). We did not receive any requests for 
a public hearing. All comments are posted at https://www.regulations.gov 
under Docket No. FWS-R6-ES-2018-0081. All substantive information 
received during the comment period is either incorporated directly into 
this final rule or is addressed below.

State Comments

    Section 4(b)(5)(A)(ii) of the Act states that the Secretary must 
give actual notice of a proposed regulation under section 4(a) to the 
State agency in each State in which the species is believed to occur, 
and invite the comments of such agency. Section 4(i) of the Act directs 
that the Secretary will submit to the State agency a written 
justification for his or her failure to adopt regulations consistent 
with the agency's comments or petition. We solicited and received 
comments from the States of Arizona (Arizona Game and Fish Department), 
Colorado (Colorado Department of Natural Resources), and Utah (Utah 
Public Lands Policy Coordinating Office). The three States support our 
reclassification of humpback chub with a section 4(d) rule.

Tribal Comments

    We received one letter from a Native American Tribe, the Navajo 
Nation, in which the Little Colorado River portion of the Grand Canyon 
population resides. On July 2, 2020, we conducted government-to-
government consultation concerning the proposed rule to reclassify 
humpback chub with a section 4(d) rule. The Navajo Nation supports our 
reclassification of humpback chub with a section 4(d) rule.

Public Comments

    We received 78 letters from the public that provided comments on 
our January 22, 2020, proposed rule (85 FR 3586). We received letters 
from the general public, nongovernmental organizations such as water 
users, power customers, and environmental organizations. All of the 
comments included their views on whether the humpback chub should be 
reclassified, with letters of support for and opposition to the 
downlisting. We considered identical comments

[[Page 57599]]

submitted by different entities to be one substantive comment, such as 
identical letters and emails submitted by multiple water user groups 
and the Sierra Club. Relevant public comments are addressed in the 
following summary, and new information was incorporated in this final 
rule.
    Comment (1): Some comments stated that the humpback chub should not 
be reclassified because population demographics do not meet the current 
recovery goals. Specifically, those comments stated that upper basin 
population abundances were too small to warrant reclassification and 
the current recovery goals include the Dinosaur National Monument 
population, which has experienced extirpation in the last two decades. 
Additional comments requested that we use the most recent population 
monitoring data to characterize the current condition of the species. 
Specifically, those comments requested that we incorporate updated 
monitoring information for the Little Colorado River, western Grand 
Canyon, and all upper basin populations.
    Our Response: We used the most recent monitoring data to 
characterize the status of the species and updated population status 
descriptions throughout the rule. The current distribution of the 
humpback chub in five extant populations across the upper and lower 
basins, with new locations emerging in the lower basin, provides 
adequate redundancy for the species. Populations are either stable 
(Grand Canyon, Desolation and Gray Canyons, Cataract Canyon, and Black 
Rocks), or are increasing (Westwater Canyon and western Grand Canyon), 
demonstrating their resiliency regardless of abundance. As summarized 
above, the current condition of the species includes adequate 
resiliency, redundancy, and representation to support species 
viability.
    We recognize that the extirpation of the Dinosaur National Monument 
population negatively affected the species and reestablishing that 
population would have conservation value to the species. Because 
existing habitats could potentially support a population, the Upper 
Basin Recovery Program has convened a team to consider translocation or 
stocking to restore humpback chub to Dinosaur National Monument. We 
support this conservation effort.
    As described under Recovery above, recovery plans provide important 
guidance to the Service, States, Tribes, and other partners on methods 
of enhancing conservation and minimizing threats to listed species, as 
well as measurable criteria against which to measure progress towards 
recovery, but they are not regulatory documents and cannot substitute 
for the determinations and promulgation of regulations required under 
section 4(a)(1) of the Act. We expect to revise the recovery plan for 
the humpback chub when this rulemaking is complete.
    Our decision to revise the status of the humpback chub is based on 
an analysis of the best scientific and commercial data available, 
regardless of whether that information differs from the recovery plan. 
As described in Determination of Status below, our review of the best 
available scientific and commercial information indicates that the 
humpback chub meets the definition of a threatened species.
    Comment (2): Some comments stated that we should not reclassify the 
species to threatened because the species will receive less protection 
under the Act. Furthermore, some comments specifically mentioned that 
if this rulemaking were finalized, there would be no regulatory 
mechanisms in place to protect the species from large-scale projects, 
including hydropower projects proposed for the Little Colorado River 
currently under Federal Energy Regulatory Commission (FERC) review.
    Our Response: Reclassification from endangered to threatened would 
not remove the species from the Federal List of Endangered and 
Threatened Wildlife. Therefore, this rule would not eliminate 
protections afforded by the Act, including prohibitions of take under 
section 9 of the Act, except as defined under this rule's special 4(d) 
provisions. Likewise, reclassification would not change in any way the 
recovery planning provisions of section 4(f) of the Act, the 
consultation requirements under section 7 of the Act, or the ability of 
the Service to enter into partnerships for the management and 
protection of the humpback chub.
    As part of this rulemaking, we developed a species-specific 4(d) 
rule, the provisions of which would promote the conservation of the 
humpback chub by providing continued protection from take and would 
facilitate the expansion of the species' range by increasing 
flexibility in management activities. These activities are intended to 
support the conservation of humpback chub. All other actions that could 
impact the species would still be governed by the Act's prohibitions of 
take under section 9 of the Act.
    The Act's section 9 take prohibitions, along with the consultation 
requirements under section 7 of the Act, would provide adequate 
regulatory oversight for projects likely to jeopardize the continued 
existence or recovery of humpback chub. This includes the proposed 
hydropower projects in the Little Colorado River under FERC 
consideration. The Department of the Interior has submitted comments on 
these projects specific to potential impacts to humpback chub. As 
stated in both of FERC's May 21, 2020, Preliminary Permits, if a 
license is pursued, FERC ``will comply with the requirements of the 
[Act] during its review of the application'' (FERC 2020a, p. 5; FERC 
2020b, p. 5).
    Comment (3): Some comments stated that the provisions of the 4(d) 
rule for humpback chub would not protect humpback chub, specifically 
the catch and release angling provisions. Conversely, all three States 
provided comments supporting the 4(d) rule provisions, with the State 
of Colorado specifically stating that all provisions are relevant to 
the recovery of the humpback chub.
    Our Response: We determined that the specific provisions in the 
4(d) rule adequately protect humpback chub while facilitating the 
conservation and management of humpback chub where they currently 
occur, and may occur in the future. We included descriptions of 
reasonable care to limit the take to humpback chub during these 
important conservation activities. Of particular note, we provide take 
prohibitions for catch-and-release angling of humpback chub only in 
areas outside of the core populations, thus protecting humpback chub 
from intentional angling pressure in these important areas.
    Comment (4): One comment stated that the proposed rule fails to 
adequately address whether the chub's most at-risk populations in the 
upper basin are still ``in danger of extinction'' and, if so, whether 
any of these higher risk populations constitute a ``significant 
portion'' of the chub's range thereby requiring the species as a whole 
to remain federally listed as endangered.
    Our Response: Based on the ruling of the court in Center for 
Biological Diversity v. Everson, 2020 WL 437289 (D.D.C. Jan. 28, 2020), 
we have revised our evaluation of the status of the humpback chub 
throughout a significant portion of its range to meet the court's 
requirements under Status Throughout a Significant Portion of Its 
Range, below.
    Comment (5): Some comments indicated that we failed to fully 
analyze and include the current and future effects of climate change in 
the Colorado River basin that cause river flow declines, such as air 
temperature increases, increased evapotranspiration,

[[Page 57600]]

and precipitation declines. Some commenters provided scientific 
research on the severe and persistent drought in the Colorado River 
since 2000, including how existing climatic warming has exacerbated 
declines in precipitation.
    Our Response: We recognize that adequate flow regimes are key to 
the conservation of humpback chub and that climate change may impact 
flow regimes in the Colorado River basin. We analyzed the current and 
expected future condition of flow regimes to support humpback chub in 
the SSA, including the ongoing and expected impact of climate change on 
this resource. Because we recognize climate change impacts will likely 
reduce water supply through a variety of mechanisms, such as less 
precipitation, warmer air temperatures, drier soils, and increased 
evapotranspiration, all future scenarios analyzed in the SSA, and used 
in this rule, assume that the mean annual availability of water 
(snowpack and runoff) will be lower in the future (Service 2018b, p. 
134). However, atmospheric conditions and water supply are not the only 
factor in realized flows in humpback chub habitats, because all 
humpback chub habitats are downstream of large federally operated 
reservoirs. Federal legislation and interstate compacts ensure that 
water is released downstream through humpback chub habitats, and 
reservoir operators have flexibility in operations. This flexibility is 
exercised in the upper basin by providing intra-annual variation in 
flows (spring peaks and base flows) tailored to the hydrological 
conditions. This can be demonstrated because, despite a severe 
reduction in water availability since 2000, water managers have 
provided intra- and inter-annual variability of flow regimes that 
support humpback chub.
    We recognize that this flexibility of water storage projects may be 
outpaced by declines in long-term water supply. Considering this 
important relationship between long-term water supply and reservoir 
operations, future resource conditions varied according to the likely 
implementation and effectiveness of reservoir operations compared with 
declining water supply (Service 2018b, p. 134). For example, Scenario 2 
in the SSA considered a future where ``water operations cannot provide 
adequate flows or temperatures in humpback chub habitats because 
drought or other factors have decreased [long-term] water supply'' 
(Service 2018b, p. 135).
    In this final rule, we have included new scientific research 
concerning climate change and water supply in the Colorado River basin 
that has been published since the completion of the SSA report (Service 
2018b, entire) and the publication of the proposed rule (January 22, 
2020; 85 FR 3586). We incorporated this new research into our final 
rule in Summary of Biological Status and Threats, including references 
provided by commenters. Despite the severe drought during the past 15 
to 20 years, management of river flows has restored much of the 
important intra- and inter-annual variability of river flow that the 
humpback chub needs to breed, feed, and shelter. Although regional 
climatic patterns are expected to reduce water availability in the 
future, the flexible operation of large dams may mitigate the impacts 
of this decrease on humpback chub through flow management and 
shepherding of water to downstream users. Although operations have been 
able to provide humpback chub with adequate flows despite the recent 
severe drought, future climatic conditions could outstrip management 
flexibility or increase frequency of drier hydrologies, which benefit 
nonnative species.
    Current river flow conditions and temperatures are largely adequate 
for humpback chub in both basins despite ongoing climatic warming. 
Therefore, we find that climate change does not place humpback chub at 
immediate risk of extinction (i.e., the species is not endangered as a 
result of climate change). The uncertainty concerning the possible 
severity in water supply declines does pose a threat to humpback chub 
in the future, such that we conclude that humpback chub is likely to 
become endangered within the foreseeable future. Therefore, our review 
of the best available scientific and commercial information, including 
recent information concerning climate change, indicates that the 
humpback chub meets the definition of a threatened species rather than 
an endangered species.
    Comment (6): Some comments stated the humpback chub is at risk from 
non-climate change related modifications to river flows, such as 
modified temperature regimes below large dams, human water use, 
declines in spring peak flows, and reduced flows in the Little Colorado 
River from aquifer diversions. Some comments requested we include 
additional descriptions of reservoir operation management actions that 
benefit humpback chub, including water provided to support peak- and 
base-flows.
    Our Response: Modified flow regimes resulting from reservoir 
operations and human water use could possibly impact humpback chub. We 
considered these potential impacts when we completed the SSA report for 
the humpback chub and in our analysis in the proposed rule. We included 
additional research and management actions into this rule in Summary of 
Biological Status and Threats, above, including references provided by 
commenters.
    We considered habitat alterations from dam operations and human 
water use, including altered river thermal regimes, spring peak flows, 
and human water withdrawals in the SSA report (Service 2018b, pp. 35, 
59, 87, 126). Current river flow conditions and temperatures are 
largely adequate for humpback chub. Therefore, we find that modified 
flow regimes from reservoir operations and human water use do not place 
humpback chub at immediate risk of extinction. Possible water supply 
declines in the future could pose a threat to humpback chub resource 
conditions, such that we conclude that humpback chub is likely to 
become endangered within the foreseeable future. The findings of our 
analysis is consistent with our determination that the humpback chub 
meets the definition of a threatened species rather than an endangered 
species.
    Comment (7): Some commenters stated that we should consider impacts 
from nonnative fish, especially nonnative trout in the Grand Canyon, 
and smallmouth bass, northern pike, and walleye in the upper basin. 
Some comments stated that the threat from nonnative fish should 
preclude its reclassification as threatened. Conversely, water user 
organizations and all three State wildlife agencies requested that we 
include additional information concerning nonnative fish management 
actions into the proposed rule and use that information to justify that 
the species does warrant reclassification.
    Our Response: Nonnative fish impact humpback chub, especially when 
nonnative fish prey upon humpback chub when their habitats overlap. In 
the SSA, we considered the presence and impacts of nonnative predators, 
such as trout in the lower basin (Service 2018b, pp. 71, 91, 128), 
smallmouth bass, northern pike, and walleye in the upper basin (Service 
2018b, pp. 42, 87, 128), and conservation actions designed to mitigate 
these threats (Service 2018b, pp. 87, 91, 97). We included additional 
research and management actions into this rule in Summary of Biological 
Status and Threats, above, including references provided by commenters.
    Current conditions of nonnative fish are acceptable to humpback 
chub because problematic, nonnative predators reproduce in only one 
extant

[[Page 57601]]

population, Desolation and Gray Canyons. Other populations do have 
nonnative predators nearby, but these predators have not colonized 
humpback chub habitats. Nonnative fish conditions are expected to 
remain acceptable in the upper basin because of the commitment to 
multifaceted nonnative fish management and existence of adequate flow 
regimes, but the risk for substantial and rapid degradation is present 
if management actions are ceased. In the lower basin, current densities 
of nonnative predators are low in areas inhabited by humpback chub, 
such as the Little Colorado River and western Grand Canyon, and 
management actions are in place to prevent establishment of new 
species. The findings of our analysis of the threat of nonnative fish 
to humpback chub is consistent with our determination that the humpback 
chub meets the definition of a threatened species rather than an 
endangered species.
    Comment (8): Some comments stated that we did not adequately 
consider possible impacts of water contamination on humpback chub, 
including impacts from oil, gas, and uranium extraction and possible 
contaminant spills.
    Our Response: In the SSA report, we stated that humpback chub needs 
suitable water quality with few contaminants and little risk of spills 
(Service 2018b, p. 28). We analyzed the current and expected future 
condition of water quality and found that it is not limiting any 
populations of humpback chub or predicted to in the foreseeable future 
(Service 2018b, pp. 50, 73); therefore, water quality was not 
considered a threat to the viability of the species.
    Comment (9): One comment stated that we did not adequately consider 
possible impacts of the parasitic Asian tapeworm on humpback chub.
    Our Response: In the SSA report, we recognized the presence of 
aquatic parasites in humpback chub habitats, including Asian tapeworm, 
but determined that no parasites or parasitic outbreak has impacted any 
humpback population (Service 2018b, p. 23). We analyzed the current and 
future expected condition of parasites and found that they are not 
limiting any populations of humpback chub or predicted to in the 
foreseeable future (Service 2018b, p. 128); therefore, this was not 
considered a threat to the viability of the species.
    Comment (10): Some comments stated that altered habitat was 
limiting the viability of humpback chub.
    Our Response: In the SSA report, we recognized that humpback chub 
needs diverse rocky canyon habitat (Service 2018b, p. 28). We analyzed 
the current and future expected condition of this resource for humpback 
chub and found that humpback chub's rocky canyon habitat is largely 
unchanged and located in lands administered by Federal, State, and 
Tribal agencies that protect the current and future condition (Service 
2018b, pp. 34, 58, 83, 86). Therefore, habitat alteration was not 
considered a threat to the viability of the species.
    Comment (11): Some comments stated that the populations of humpback 
chub are fragmented, especially by Glen Canyon Dam, and that lack of 
connectivity reduces the genetic fitness of the species.
    Our Response: In the SSA report, we recognized that the humpback 
chub requires connectivity (Service 2018b, p. 29). We analyzed the 
current and future expected condition of connectivity for humpback chub 
and found that at a species level, Glen Canyon Dam is a barrier to 
movement between the upper and lower basins. Within the upper basin, 
there is no impediment to movement among the four extant populations 
because multiple fish passage projects have been built and operated 
over the past two decades. Movement of individuals in the upper basin 
are sufficient to ensure genetic exchange and diversity, but not 
sufficient to repopulate other areas (Service 2018b, p. 52). In the 
lower basin, connectivity between the Little Colorado River population 
and other aggregations downstream is sufficient for genetic exchange, 
but the demographic effect is unclear (Service 2018b, p. 75). There are 
no barriers between the Little Colorado River and the newly expanded 
population in the western Grand Canyon.
    Because humpback chub in the upper and lower basin can freely swim 
between habitats in each basin, population connectivity was not 
considered a threat to the viability of the species. In the 2002 
Recovery Goals we determined that recovery of the species can be 
achieved via two unconnected recovery units, the lower basin and upper 
basin, demarcated at Glen Canyon Dam. The findings of our analysis of 
connectivity within the range of humpback chub is consistent with our 
determination that the humpback chub meets the definition of a 
threatened species rather than an endangered species.
    Comment (12): Some comments stated that we did not appropriately 
consider the impact of food supply in the Grand Canyon and requested 
that we incorporate additional information from recent studies of 
macroinvertebrate flows in the Grand Canyon.
    Our Response: In the SSA report, we recognized that humpback chub 
need an adequate and reliable food supply (Service 2018b, p. 28). We 
analyzed the current and future expected condition of this resource for 
humpback chub and found the aquatic food base in Grand Canyon is 
affected by temperature, daily flow variation, and fish competition, 
which may limit the size of the humpback chub population (Service 
2018b, p. 68); therefore, we considered this impact to the viability of 
the species in the proposed rule.
    Discharge variation from hydropeaking operations in the Grand 
Canyon limits the success of aquatic egg-laying insect species whose 
eggs are desiccated during the incubation cycle. It is unclear if 
ongoing macroinvertebrate production flow experiments have increased 
long-term macroinvertebrate density (Kennedy and Meuhlbauer 2020, pp. 
12-20) or if they will appreciably improve humpback chub condition. We 
incorporated this research and management action into this rule in 
Summary of Biological Status and Threats, including references provided 
by commenters. The findings of our analysis of food supply within the 
range of humpback chub is consistent with our determination that the 
humpback chub meets the definition of a threatened species rather than 
an endangered species.
    Comment (13): Some comments requested that we update our 
description of the future of the Upper Basin Recovery Program to 
include the most recent planning of program partners. The comments 
stated that the uncertainty regarding the future of the Upper Basin 
Recovery Program, as described in Scenario 1, was not justified because 
program partners have a strong commitment to future implementation of 
the program.
    Our Response: We have included new information from the planning 
process to reauthorize the Upper Basin Recovery Program in our Summary 
of Biological Status and Threats, above. We understand that the 
partners are working diligently to find a framework for the Upper Basin 
Recovery Program to continue after 2023. The past performance of the 
Upper Basin Recovery Program's implementation of recovery actions over 
the past three decades cannot be discounted. However, at this time, 
there are no signed extensions or reauthorizations of the program on 
which we can rely for this rule. Until the Upper Basin Recovery Program 
partnership is defined, the humpback chub's future resource conditions 
are not certain

[[Page 57602]]

because critical management actions, such as leasing water for river 
flows, in-river nonnative fish removal, fish passage operations, and 
monitoring may not be implemented.
    We must rely on the best available information when making our 
determination and at this time we must recognize that there is 
uncertainty in the future structure and funding for the Upper Basin 
Recovery Program. Therefore, we did not alter the analysis of Scenario 
1 presented in the SSA report.

Determination of Humpback Chub 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.'' For a more detailed discussion on the factors considered when 
determining whether a species meets the definition of an endangered 
species or a threatened species and our analysis on how we determine 
the foreseeable future in making these decisions, please see Regulatory 
and Analytical Framework.

Status Throughout All of Its Range

    As required by the Act, we considered the five factors in assessing 
whether humpback chub is an endangered or threatened species throughout 
all of its range. We carefully examined the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by humpback chub. We reviewed the information 
available in our files and other available published and unpublished 
information and information that we received from public comments on 
our January 22, 2020, proposed rule (85 FR 3586), and we consulted with 
recognized experts and State agencies. We documented our analysis in an 
SSA report (Service 2018b, entire).
    We identified changes to water flow and temperature (Factor A), 
food availability (Factor A), and predatory, nonnative fish (Factor C) 
as potential stressors to humpback chub (Service 2018b, pp. 126-133). 
There is no evidence that overutilization (Factor B) of humpback chub, 
disease (Factor C), or other natural and manmade factors affecting the 
species (Factor E) are occurring. We evaluated each potential stressor, 
including its source, affected resources, exposure, immediacy, 
geographic scope, magnitude, and impacts on individuals and 
populations, and our level of certainty regarding this information, to 
determine which stressors were likely to be drivers of the species' 
current and future conditions (Service 2018b, pp. 126-133). We also 
evaluated the effects of stressors that may operate cumulatively, such 
as low river flows and warm water temperatures that may act 
cumulatively to increase predation by nonnative predators.
    As described in the determinations below, we first evaluate whether 
the humpback chub is in danger of extinction throughout its range now. 
We then evaluate whether the species is likely to become in danger of 
extinction throughout its range in the foreseeable future. We finally 
consider whether the humpback chub is an endangered or threatened 
species in a significant portion of its range.
    In this finding, we evaluate the best available scientific 
information about the species' current and projected future levels of 
demographic and habitat factors (these are described in the SSA report 
in terms of resiliency, redundancy, and representation) to describe the 
viability of the species, and how it may change over time (using three 
plausible future scenarios). Ultimately, we compare our evaluation of 
the species risk of extinction against the definition of an endangered 
species.
    As summarized above, resource conditions for the humpback chub 
across five extant populations, four in the upper basin and one large 
population in the lower basin, are adequate. Habitats support multiple, 
resilient populations in the upper basin, including the large Westwater 
Canyon population, and the large, stable Grand Canyon population in the 
lower basin, with range expansion into western Grand Canyon. The 
species currently demonstrates sufficient levels of resiliency, 
redundancy, and representation across both the upper basin and lower 
basin populations, such that the potential extirpation of multiple 
populations is not likely to occur now or in the short term. The 
current resiliency of the large core population in the lower basin and 
the current resiliency and redundancy of the four populations in the 
upper basin decrease the risk to the species from stochastic and 
catastrophic events, such that the species currently has a low risk of 
extinction.
    Thus, after assessing the best available information, we conclude 
that the humpback chub no longer meets the Act's definition of an 
endangered species. We therefore proceed with determining whether the 
humpback chub is likely to become endangered within the foreseeable 
future throughout all of its range.
    The key statutory difference between a threatened species and an 
endangered species is the timing of when a species may be in danger of 
extinction, either now (endangered species) or in the foreseeable 
future (threatened species).
    In considering the foreseeable future, we projected a range of 
plausible future scenarios for the humpback chub and evaluated the 
condition of demographic factors and habitat factors under each future 
scenario. We then summarized the future viability for the species in 
terms of its resiliency, redundancy, and representation under each of 
the three future scenarios. For the purposes of this finding, we 
generally define viability as the ability of the species to sustain a 
population in the wild over a biologically meaningful timeframe, in 
this case, 16 to 40 years into the future, a biologically meaningful 
timeframe that represents multiple generations of humpback chub. The 
timeframe should be sufficient to be able to observe changes in the 
condition of the species through multiple generations, multiple cycles 
of changes to climate conditions, such as drought, and is a timeframe 
in which we can reasonably rely on projections about the future.
    To assist us in evaluating the status of the species in the 
foreseeable future, we evaluated the future condition of the humpback 
chub under three plausible future scenarios, 16 and 40 years into the 
future. These scenarios were designed to capture the full range of 
plausible futures and uncertainty associated with the implementation 
and effectiveness of conservation actions important to the humpback 
chub's survival. Although the likelihood of each scenario occurring in 
the future may vary, the changes in conservation efforts projected by 
the three scenarios are all plausible, so the scenarios capture the 
full range of conditions that the humpback chub could experience 16 and 
40 years into the future. We evaluated the viability of the humpback 
chub under each of these scenarios in terms of its expected resiliency, 
redundancy, and representation into the foreseeable future.
    Looking into the foreseeable future, habitat and demographic 
conditions for the humpback chub would severely degrade within both 16 
and 40 years under Scenario 1, primarily in the upper basin. However, 
if collaborative partnerships remain in place and their

[[Page 57603]]

conservation actions are effective as described under Scenario 3, 
resource conditions improve at both the 16- and 40-year timeframes. 
However, under Scenario 2, degradation of resources takes place, even 
as conservation actions continue, resulting in the same conditions as 
current condition within 16 years, but reduced conditions within 40 
years. Although there is high uncertainty associated with the 
projection of the resource conditions in 40 years under Scenario 2, 
extrapolation of the conditions demonstrates a continuing decline in 
resource conditions under Scenario 2. The potential extirpation of 
multiple populations could most likely occur in the upper basin under 
the short 16-year timeframe in Scenario 1 and the longer 40-year 
timeframe under Scenario 2. Under Scenario 3, ongoing threat management 
proves successful in the long term, improving resource conditions. 
Under Scenario 3, the health (resiliency) and distribution (redundancy) 
of all five extant populations reduces the risk from a potential 
catastrophic event, but there is less resiliency and redundancy under 
Scenarios 1 and 2, which represents more risk to the species.
    Based on the uncertain trajectory of several of the upper basin 
populations; the uncertainty associated with certain resource 
conditions, including nonnative predatory fish, river flow, and food 
supply in the Grand Canyon; and the unresolved future of the Upper 
Basin Recovery Program, the future conditions for the populations and 
overall species viability are at increased risk and could decline 
within 40 years under Scenarios 1 and 2. Future conditions would only 
improve under Scenario 3 if long-term management actions are 
successful.
    Therefore, there is enough risk in the foreseeable future 
associated with potential reductions in conservation actions that are 
important to the species' survival, such that the humpback chub is 
likely to become endangered throughout all of its range within the 
foreseeable future. Specifically, there is enough risk associated with 
the potential reduction of important management actions, which could 
occur with reduced funding in the Upper Basin Recovery Program, such 
that the humpback chub is at risk of extinction in the foreseeable 
future.
    Thus, after assessing the best available information, we determine 
that the humpback chub is not currently in danger of extinction, but is 
likely to become in danger of extinction within the foreseeable future 
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. The court in Center for Biological Diversity v. Everson, 
2020 WL 437289 (D.D.C. Jan. 28, 2020) (Center for Biological 
Diversity), vacated the aspect 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) that provided that the Services 
do not undertake an analysis of significant portions of a species' 
range if the species warrants listing as threatened throughout all of 
its range. Therefore, we proceed to evaluating whether the species is 
endangered 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 
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.
    Following the court's holding in Center for Biological Diversity, 
we now consider whether there are any significant portions of the 
species' range where the species is in danger of extinction now (i.e., 
endangered). In undertaking this analysis for the humpback chub, we 
choose to address the status question first--we consider information 
pertaining to the geographic distribution of both the species and the 
threats that the species faces to identify any portions of the range 
where the species is endangered.
    For the humpback chub, we considered whether the threats are 
geographically concentrated in any portion of the species' range at a 
biologically meaningful scale. We examined the following threats: River 
flows and water temperature (which could be affected by climate change 
in the long term) (Factor A), food supply (Factor A), and predatory 
nonnative fish (Factor C), including cumulative effects. There is no 
evidence that overutilization (Factor B) of humpback chub, disease 
(Factor C), or other natural and manmade factors affecting the species 
(Factor E) are occurring.
    Current river flow conditions and temperatures are largely adequate 
for humpback chub throughout its range, in both the upper and lower 
basins, because reservoir operations have had the flexibility and 
commitment to support humpback chub. Despite the severe drought 
experienced during the past 15 to 20 years across the species' range, 
management of river flows has restored much of the important intra- and 
inter-annual variability of river flow that the humpback chub needs to 
breed, feed, and shelter. Specifically, in the upper basin, changes in 
the operation of large Federal dams and provision of water dedicated to 
environmental flows have reduced the effects of drought on river flows. 
Therefore, despite a severe reduction in water availability since 2000, 
water managers have provided flow regimes in upper basin rivers that 
support humpback chub, and upper basin populations have stabilized or 
expanded in response. As a result, we did not identify a concentration 
of threats associated with either river flows or water temperature.
    In the lower basin, the Long-Term Experimental and Management Plan 
prescribes release patterns from Glen Canyon Dam, helping to reduce and 
minimize impacts to Grand Canyon habitats. This includes experimental 
releases to support the aquatic food base in Grand Canyon. Currently, 
the water flows, water temperatures, and food base in the Grand Canyon 
have supported a large, stable population in the Colorado River and are 
supporting a range expansion in the western Grand Canyon. As such, we 
did not identify a concentration of threats in the lower basin.
    Current river flow conditions have supported humpback chub 
populations in both the upper and lower basins and have helped reduce 
the presence of nonnative predatory fish species in humpback chub 
habitats, despite populations of predators nearby. Additionally, 
nonnative fish management actions have helped reduce nonnative 
predatory species, such as in-river nonnative predator removal, active 
flow management, and reservoir containment. As a result, nonnative 
predators are not limiting three out-of-the four extant humpback chub 
populations in the upper basin, and are a moderate issue for one 
population in the upper basin. Smallmouth bass inhabit and reproduce in 
Dinosaur National Monument, so nonnative predators could potentially be 
an issue if Dinosaur National Monument supported a humpback chub 
population

[[Page 57604]]

and was not extirpated, but we did not identify a concentration of 
nonnative predators in this area. In the lower basin, nonnative fish 
are likely limited by abiotic factors, so nonnative predators are not 
an issue across the majority of humpback chub habitats in the lower 
basin, including the Little Colorado River and western Grand Canyon 
(Pillow et al. 2018, p. 7; Van Haverbeke et al. 2019, p. 8; Kegerries 
et al. 2020, p. 146). Management actions are also in place to prevent 
establishment of new nonnative species in the lower basin, including 
the NPS ``Expanded Nonnative Species Management Plan,'' which provides 
additional tools and new approaches for controlling nonnative aquatic 
species (NPS 2018, pp. 1-3). Therefore, we did not identify any 
concentration of threats associated with nonnative predators across the 
range of the species.
    We found no concentration of threats in any portion of the humpback 
chub range at a biologically meaningful scale. Thus, there are no 
portions of the species' range where the species has a different status 
from its rangewide status. Therefore, no portion of the species' range 
provides a basis for determining that the species is in danger of 
extinction in a significant portion of its range, and we determine that 
the species is likely to become in danger of extinction within the 
foreseeable future throughout all of its range. This is consistent with 
the courts' holdings in Desert Survivors v. Department of the Interior, 
No. 16-cv-01165-JCS, 2018 WL 4053447 (N.D. Cal. Aug. 24, 2018), and 
Center for Biological Diversity v. Jewell, 248 F. Supp. 3d, 946, 959 
(D. Ariz. 2017).

Determination of Status

    Our review of the best available scientific and commercial 
information indicates that humpback chub does not meet the definition 
of an endangered species in accordance with sections 3(6) and 4(a)(1) 
of the Act, but does meet the definition of a threatened species in 
accordance with sections 3(20) and 4(a)(1) of the Act. Therefore, we 
are downlisting humpback chub in the List of Endangered and Threatened 
Wildlife from endangered to threatened.

Final Rule Issued Under Section 4(d) of the Act

    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is classified, those activities that would or would 
not constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a listing on 
proposed and ongoing activities within the range of the species being 
listed. Because we are reclassifying this species as a threatened 
species, the prohibitions in section 9 would not apply directly. We are 
therefore putting into place below a set of regulations to provide for 
the conservation of the species in accordance with section 4(d), which 
also authorizes us to apply any of the prohibitions in section 9 to a 
threatened species. The 4(d) rule, which includes a description of the 
kinds of activities that would or would not constitute a violation, 
complies with this policy.

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the ``Secretary shall issue such regulations as he deems 
necessary and advisable to provide for the conservation'' of species 
listed as threatened. The U.S. Supreme Court has noted that statutory 
language like ``necessary and advisable'' demonstrates a large degree 
of deference to the agency (see Webster v. Doe, 486 U.S. 592 (1988)). 
Conservation is defined in the Act to mean ``the use of all methods and 
procedures which are necessary to bring any endangered species or 
threatened species to the point at which the measures provided pursuant 
to [the Act] are no longer necessary.'' Additionally, the second 
sentence of section 4(d) of the Act states that the Secretary ``may by 
regulation prohibit with respect to any threatened species any act 
prohibited under section 9(a)(1), in the case of fish or wildlife, or 
section 9(a)(2), in the case of plants.'' Thus, the combination of the 
two sentences of section 4(d) provides the Secretary with wide latitude 
of discretion to select and promulgate appropriate regulations tailored 
to the specific conservation needs of the threatened species. The 
second sentence grants particularly broad discretion to us when 
adopting the prohibitions under section 9.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld rules 
developed under section 4(d) as a valid exercise of agency authority 
where they prohibited take of threatened wildlife, or include a limited 
taking prohibition (see Alsea Valley Alliance v. Lautenbacher, 2007 
U.S. Dist. Lexis 60203 (D. Or. 2007); Washington Environmental Council 
v. National Marine Fisheries Service, 2002 U.S. Dist. Lexis 5432 (W.D. 
Wash. 2002)). Courts have also upheld 4(d) rules that do not address 
all of the threats a species faces (see State of Louisiana v. Verity, 
853 F.2d 322 (5th Cir. 1988)). As noted in the legislative history when 
the Act was initially enacted, ``once an animal is on the threatened 
list, the Secretary has an almost infinite number of options available 
to him with regard to the permitted activities for those species. He 
may, for example, permit taking, but not importation of such species, 
or he may choose to forbid both taking and importation but allow the 
transportation of such species'' (H.R. Rep. No. 412, 93rd Cong., 1st 
Sess. 1973).
    Exercising this authority under section 4(d), we have developed a 
species-specific 4(d) rule that is designed to address the humpback 
chub's specific threats and conservation needs. Although the statute 
does not require us to make a ``necessary and advisable'' finding with 
respect to the adoption of specific prohibitions under section 9, we 
find that this rule as a whole satisfies the requirement in section 
4(d) of the Act to issue regulations deemed necessary and advisable to 
provide for the conservation of the humpback chub. As discussed above 
under the Determination of Humpback Chub's Status section, we conclude 
that the humpback chub is no longer at risk of extinction, but is still 
likely to become so in the foreseeable future, primarily due to changes 
to water flow and temperature, food availability, and predatory, 
nonnative fish. The provisions of this 4(d) rule promote conservation 
of the humpback chub by providing continued protection from take, 
encouraging improvements to the species' habitat, and facilitating the 
expansion of the species' range by increasing flexibility in management 
activities. The provisions in this rule are some of many regulatory 
tools that we will use to promote the conservation of the humpback 
chub.

Provisions of the 4(d) Rule

    This 4(d) rule provides for the conservation of the humpback chub 
by prohibiting the following activities, with certain exceptions 
(discussed below): Importing or exporting; possession and other acts 
with unlawfully taken specimens; delivering, receiving, transporting, 
or shipping in interstate or foreign commerce in the course of 
commercial activity; or selling or offering for sale in interstate or 
foreign commerce. In addition, anyone taking, attempting to take, or 
otherwise possessing a humpback chub, or parts thereof, in violation of 
section 9 of the Act will be subject to a penalty under section 11 of 
the Act, with certain

[[Page 57605]]

exceptions (discussed below). Under section 7 of the Act, Federal 
agencies must continue to ensure that any actions they authorize, fund, 
or carry out are not likely to jeopardize the continued existence of 
the humpback chub.
    Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, or collect, or to attempt to engage in any 
such conduct. Some of these provisions have been further defined in 
regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by 
direct and indirect impacts, intentionally or incidentally. Allowing 
incidental and intentional take in certain cases, such as for the 
purposes of scientific inquiry, monitoring, or to improve habitat or 
water availability and quality, would help preserve a species' 
remaining populations, slow their rate of decline, and decrease 
synergistic, negative effects from other stressors.
    We recognize the special and unique relationship with our State 
natural resource agency partners in contributing to conservation of 
listed species. State agencies often possess scientific data and 
valuable expertise on the status and distribution of endangered, 
threatened, and candidate species of wildlife and plants. State 
agencies, because of their authorities and their close working 
relationships with local governments and landowners, are in a unique 
position to assist us in implementing all aspects of the Act. In this 
regard, section 6 of the Act provides that we shall cooperate to the 
maximum extent practicable with the States in carrying out programs 
authorized by the Act. Therefore, any qualified employee or agent of a 
State conservation agency that is a party to a cooperative agreement 
with us in accordance with section 6(c) of the Act, who is designated 
by his or her agency for such purposes, will be able to conduct 
activities designed to conserve the humpback chub that may result in 
otherwise prohibited take without additional authorization.
    As discussed above under Summary of Biological Status and Threats, 
changes to water flow and temperature, food availability, and 
predatory, nonnative fish affect the status of the humpback chub. A 
range of conservation activities, therefore, have the potential to 
benefit the humpback chub, including nonnative fish removal, habitat 
restoration projects, monitoring of humpback chub, management of 
recreational fisheries, research, educational and outreach programs, 
and maintenance of humpback chub refuges and stocking programs. 
Accordingly, this 4(d) rule addresses activities to facilitate 
conservation and management of the humpback chub where they currently 
occur and may occur in the future by excepting them from the Act's take 
prohibition under certain specific conditions. These activities are 
intended to increase management flexibility and encourage support for 
the conservation and habitat improvement of the humpback chub. Under 
this 4(d) rule, take will continue to be prohibited, except for actions 
allowed in this 4(d) rule, provided the actions are approved by the 
Service, in coordination with any existing designated recovery program, 
for the purpose of the conservation or recovery of the humpback chub. 
Approval must be in writing (by letter or email) from a Service 
biologist or supervisor with authority over humpback chub decisions. 
Take is allowed under this 4(d) rule as follows, and is further 
described below:
     Take resulting from creating and maintaining humpback chub 
refuge populations;
     Take resulting from expanding the range of the species, 
including translocating wild fish and stocking hatchery-reared fish;
     Incidental take from reducing or eliminating nonnative 
fish from habitats adjacent to, or occupied by, humpback chub;
     Take resulting from catch-and-release angling activities 
associated with humpback chub, including incidental take from non-
humpback chub-targeted angling in the six core populations and take 
from humpback chub-targeted angling in any newly established areas; and
     Take associated with chemical treatments in support of the 
recovery of humpback chub.
    These forms of allowable take are explained in more detail below. 
For all forms of allowable take, reasonable care must be practiced to 
minimize the impacts from the actions. Reasonable care means limiting 
the impacts to humpback chub individuals and populations by complying 
with all applicable Federal, State, and Tribal regulations for the 
activity in question; using methods and techniques that result in the 
least harm, injury, or death, as feasible; undertaking activities at 
the least impactful times and locations, as feasible; procuring and 
implementing technical assistance from a qualified biologist on 
projects regarding all methods prior to the implementation of those 
methods; ensuring the number of individuals removed or sampled 
minimally impacts the existing wild population; ensuring no disease or 
parasites are introduced into the existing humpback chub population; 
and preserving the genetic diversity of wild populations.

Creation and Maintenance of Refuge Populations

    Establishing and maintaining humpback chub refuge populations is an 
important consideration for long-term humpback chub viability because 
refuge populations safeguard genetic diversity against catastrophic 
declines in wild populations and can be necessary to protect a 
population from extirpation. In the case of declining wild populations, 
refuge populations provide the flexibility to perform supplemental 
stocking into existing populations or reintroduction of individuals to 
extirpated areas. Refuge populations may also allow for stocking of 
individuals into new areas that expand the range of the species (see 
Translocation or Stocking of Humpback Chub, below). The process of 
establishing and supplementing refuge populations requires take in the 
form of collection of wild individuals of various life stages. 
Furthermore, the long-term care and maintenance of refuge populations 
will result in take, including death of individuals held in captivity. 
However, preservation of genetic diversity in refuge populations 
outweighs any losses to wild populations if performed in a deliberate, 
well-designed process.
    Currently, some, but not all, of the genetic diversity of humpback 
chub exists in captive refuge populations. Approximately 1,000 
individuals from the Grand Canyon population are managed as a refuge 
population at the Southwestern Native Aquatic Resources and Recovery 
Center in Dexter, New Mexico; additionally, a small number of adults 
from the Black Rocks and Desolation and Gray Canyons populations reside 
at the Ouray National Fish Hatchery. In order to preserve the full 
breadth of genetic diversity of humpback chub, creation of additional 
refuge populations could be suggested in the revised humpback chub 
recovery plan, by the Service, or in other proceedings, such as section 
7 consultations between the Service and Federal agencies. We expect to 
revise the recovery plan for humpback chub when this rulemaking process 
is complete.
    This 4(d) rule describes creation and maintenance of humpback chub 
refuge populations excepted from take as activities undertaken for the 
long-term protection of humpback chub genetic diversity. Refuge 
populations must include specific genetic groupings of humpback chub as 
defined by the best available science and must be managed

[[Page 57606]]

to maintain the genetic diversity of the species. Refuge populations 
can occur at both captive and wild locations.
    The Service must approve in writing the designation of a refuge 
population, and any removal of individuals from wild populations. 
Subsequent to those approvals, under this 4(d) rule, the Service would 
no longer regulate the take associated with maintenance of that 
population. Take associated with refuge populations could include 
harvest of wild individuals from extant populations; incidental take 
during the long-term care of individuals in captivity; take related to 
disease, parasite, genetic assessment, and management of captive 
populations; and natural mortality of individuals existing in refuge 
populations.

Translocation and Stocking of Humpback Chub

    Translocating wild humpback chub and stocking hatchery-reared 
humpback chub are important management actions supporting the long-term 
viability of the species. Introducing individuals into new areas can 
provide increased redundancy and decreased risk to catastrophic events 
by expanding the range of the species. Introducing individuals into 
wild populations can provide increased resiliency for extant 
populations by potentially offsetting population declines or increasing 
genetic diversity. The process of translocating wild individuals can 
result in take to wild individuals, including possible mortality to 
fish that are moved. The process of culturing and stocking individuals 
can also result in take via hatchery methods or incidental mortality of 
stocked individuals. However, if the translocation or stocking program 
is performed under a deliberate, well-designed program, the benefits to 
the species can greatly outweigh the losses.
    Translocations of wild humpback chub to new locations have 
demonstrated success in the Grand Canyon as described above in The 
Lower Basin. Between 2003 and 2015, juvenile humpback chub were 
translocated from the Little Colorado River to Shinumo Creek, Havasu 
Creek, and the Little Colorado River above Chute Falls. At all three 
locations, translocated fish established residency and demonstrated 
acceptable growth rates, increasing the range of the species (although 
the Shinumo Creek population was later extirpated via ash-laden floods 
following a wildfire). The Havasu Creek and Chute Falls populations 
also demonstrated wild reproduction and recruitment, further supporting 
the management action of translocations for expanding the range of the 
humpback chub. Based on these successes, translocation appears to be a 
possible tool to reintroduce individuals into the Dinosaur National 
Monument population or to expand the range of humpback chub into other 
areas.
    Currently, humpback chub are not cultured in hatcheries, nor are 
any broodstock fish maintained at a hatchery. However, in the future, 
hatchery production and culture may be a necessary tool either to 
supplement existing populations or to introduce individuals to new 
locations without harvesting wild fish.
    This 4(d) rule describes translocation and stocking of humpback 
chub excepted from take as any activity undertaken to expand the range 
of humpback chub or to supplement existing wild populations. Take from 
translocation could include harvest and movement of wild individuals 
from extant populations to new areas and subsequent mortality of fish 
in new locations. Any translocation program must be approved in writing 
by the Service. Take from stocking programs could include take during 
the long-term care of individuals in captivity; take related to 
disease, parasite, genetic assessment, and management of captive 
populations while they are in captivity; and take from stocking, 
including subsequent mortality of stocked individuals. Any harvest of 
wild fish to support a stocking program must comply with the conditions 
described above under Creation and Maintenance of Refuge Populations. 
Any stocking of humpback should follow best hatchery and fishery 
management practices, such as those described in the American Fisheries 
Society's Fish Hatchery Management (Wedemeyer 2002, entire), and be 
approved by the Service in writing.

Nonnative Fish Removal

    Control of nonnative fishes is vital for the continued recovery of 
humpback chub because predatory nonnative fishes are a principal threat 
to humpback chub (see Summary of Biological Status and Threats, above). 
Removal of nonnative fishes reduces predation and competition pressure 
on humpback chub, increasing humpback chub survival, recruitment, and 
access to resources. During the course of removing nonnative fishes, 
take of humpback chub may occur from incidental captures resulting in 
capture, handling, injury, or possible mortality. However, nonnative 
removal activities in humpback chub habitats are designed to be 
selective, allowing for the removal of predatory, nonnative fish while 
humpback chub are returned safely to the river. Therefore, if nonnative 
fish removal is performed under deliberate, well-designed programs, the 
benefits to humpback chub can greatly outweigh losses.
    Currently, active nonnative fish removal is widespread in the upper 
basin, but is less common in the lower basin. Control of nonnative 
fishes is conducted by qualified personnel in the upper basin via 
mechanical removal using boat-mounted electrofishing, nets, and seines, 
primarily focusing on removal of smallmouth bass, northern pike, and 
walleye. Removal of nonnative fishes in the upper basin is performed 
under strict standardized protocols to limit impacts to humpback chub. 
In the lower basin, nonnative fish actions primarily focus on 
preventing establishment of new species (such as removal of green 
sunfish below Glen Canyon Dam) and controlling populations of trout in 
tributary habitats (such as removal of brown trout in Bright Angel 
Creek). New techniques, as available and feasible, may also need to be 
implemented in the future.
    This 4(d) rule defines nonnative fish removal as any action with 
the primary or secondary purpose of mechanically removing nonnative 
fishes that compete with, predate, or degrade the habitat of humpback 
chub, and that is approved in writing by the Service for that purpose. 
These methods include mechanical removal within occupied humpback chub 
habitats, including, but not limited to, electrofishing, seining, 
netting, and angling, or other ecosystem modifications such as altered 
flow regimes or habitat modifications. All methods must be conducted by 
qualified personnel and used in compliance with applicable Federal, 
State, and Tribal regulations. Whenever possible, humpback chub that 
are caught alive as part of nonnative fish removal should be returned 
to their capture location as quickly as possible.

Catch-and-Release Angling of Humpback Chub

    Recreational angling is an important consideration for management 
of all fisheries, as recreational angling is the primary mechanism by 
which the public interacts with fishes. Furthermore, angling 
regulations are an important communication tool. While the humpback 
chub is not currently a species that is prized for its recreational or 
commercial value, the species is a large-bodied, catchable-sized fish 
that could offer potential recreational value in certain situations. 
Conservation value from public support for humpback chub could arise 
through newly established

[[Page 57607]]

fishing locations and public engagement with this species. Furthermore, 
anglers target species that co-occur with humpback chub at some 
locations. As a result, otherwise legal angling activity in humpback 
chub habitats could result in the unintentional catch of humpback chub 
by the angling public. Catch-and-release angling, both intentional and 
incidental, can result in take of humpback chub through handling, 
injury, and potential mortality. However, the conservation support that 
angling provides can outweigh losses to humpback chub, if the angling 
program is designed appropriately.
    Currently, State angling regulations require the release of all 
incidental catches of humpback chub and do not allow anglers to target 
the species. Therefore, current angling regulations for humpback chub 
by the States of Arizona, Colorado, and Utah demonstrate a willingness 
to enact appropriate regulations for the protection of the humpback 
chub. It is important to continue to protect humpback chub from 
intentional (i.e., targeted) angling pressure in the six core 
populations (five extant and one extirpated) because of their 
importance to the recovery of the species. Supporting recreational 
fishing access to these areas for species other than humpback chub is 
an important consideration for State and Tribal entities. We allow 
incidental take of humpback chub from angling activities that are in 
accordance with State and Tribal fishing regulations in the six core 
humpback chub populations, but that do not target humpback chub. That 
is, incidental take associated with incidental catch-and-release of 
humpback chub in the core populations would not be prohibited. 
Reasonable consideration by the States and Tribes for incidental catch 
of humpback chub in the six core populations include: (1) Regulating 
tactics to minimize potential injury and death to humpback chub if 
caught; (2) communicating the potential for catching humpback chub in 
these areas; and (3) promoting the importance of the six core 
populations.
    Outside of the six core populations, we foresee that Federal, 
State, or Tribal governments may want to establish a new location where 
humpback chub could be targeted for catch-and-release angling. Newly 
established locations could offer a genetic refuge for core populations 
of humpback chub (see Creation and Maintenance of Refuge Populations, 
above), provide a location for hatchery-reared fish (see Translocation 
and Stocking of Humpback Chub, above), and offer the public a chance to 
interact with the species in the wild. Therefore, we allow intentional 
take of humpback chub from catch-and-release angling activities that 
target humpback chub and are in accordance with State and Tribal 
fishing regulations in areas outside of the six core humpback chub 
populations.
    Sport fishing for humpback chub would only be allowed through the 
4(d) rule and subsequent State or Tribal regulations created in 
collaboration with the Service. This rule would allow recreational 
catch-and-release fishing of humpback chub in specified waters, not 
including the six core populations. Management as a recreational 
species would be conducted after completion of, and consistent with the 
goals within, a revised recovery plan for the species. The principal 
effect of this 4(d) rule would be to allow take in accordance with 
fishing regulations enacted by States or Tribes, in collaboration with 
the Service.
    Recreational opportunities may be developed by the States and 
Tribes in new waters following careful consideration of the locations 
and impacts to the species. Reasonable consideration for establishing 
new recreational locations for humpback chub include, but are not 
limited to: (1) Carefully evaluating each water body and determining 
whether the water body can sustain angling; (2) ensuring the population 
does not detrimentally impact core populations of humpback chub through 
such factors as disease or genetic drift; (3) ensuring adequate 
availability of humpback chub to support angling; and (4) monitoring to 
ensure there are no detrimental effects to the population from angling. 
If monitoring indicates that angling has a negative effect on the 
conservation of humpback chub in the opinion of the Service, the 
fishing regulations must be amended or the fishery could be closed by 
the appropriate State.

Chemical Treatments Supporting Humpback Chub

    Chemical treatments of water bodies are an important fisheries 
management tool because they are the principal method used to remove 
all fishes from a defined area. That is, chemical treatments provide 
more certainty of complete removal than other methods, such as 
mechanical removal. Therefore, chemical treatments are used for a 
variety of restoration and conservation purposes, such as preparing 
areas for stocking efforts, preventing nonnative fishes from colonizing 
downstream areas, and resetting locations after failed management 
efforts. Chemical treatments of water bodies could take humpback chub 
if individuals reside in the locations that are treated and cannot be 
salvaged completely prior to treatment. However, the overall benefit of 
conservation actions implemented using chemical treatment can outweigh 
the losses of humpback chub, if careful planning is taken prior to 
treatments.
    Chemical piscicides (chemicals that are poisonous to fish) have 
been used in the upper and lower basin to remove upstream sources of 
nonnative fishes in support of humpback chub. For example, Red Fleet 
Reservoir (Green River, Utah) was treated by Utah Division of Wildlife 
Resources to remove walleye that were escaping downstream, and a slough 
downstream of Glen Canyon Dam (Colorado River, Arizona) was treated by 
NPS to remove green sunfish before they could invade humpback chub 
habitat. At Red Fleet Reservoir, chemical treatment also provided the 
Utah Division of Wildlife Resources with the ability to establish a new 
fish community that supported angling interests and provided greater 
compatibility with downstream conservation efforts.
    Chemical treatments could support a variety of activities to assist 
in the conservation of humpback chub, including certain other actions 
described in this 4(d) rule. For example, chemical treatments could be 
used prior to introducing humpback chub to a wild refuge population, a 
translocation site, or a sport fishing location. Nonnative fishes can 
also be removed using chemical treatments, providing a faster and more 
complete removal than mechanical removal. Furthermore, chemical 
treatments offer the ability to fully restore a location after a failed 
introduction effort. For example, if humpback chub were stocked into a 
new area, but did not successfully establish, landowners may want to 
restore this location for another purpose.
    Chemical treatments would be allowed under this 4(d) rule. 
Necessary precautions and planning should be applied to avoid impacts 
to humpback chub. For example, treatments upstream of occupied humpback 
chub habitats should adhere to all protocols to limit the potential for 
fish toxicants and piscicides traveling beyond treatment boundaries. 
Chemical treatments that take place in locations where humpback chub 
occur, or may occur, must take place only after a robust salvage effort 
takes place to remove humpback chub in the area. Whenever possible, 
humpback chub that are salvaged should be moved to a location that 
supports recovery of the species. Any chemical treatment that takes 
place in an area where humpback chub may

[[Page 57608]]

reside would need written approval from the Service, but treatments of 
unoccupied habitat would not need to be approved. Once the location of 
a chemical treatment is approved in writing by the Service, the take of 
humpback chub by qualified personnel associated with performing a 
chemical treatment would not be regulated by the Service.

Reporting and Disposal of Humpback Chub

    Under the 4(d) rule, if humpback chub are killed during actions 
described in the 4(d) rule, the Service must be notified of the death 
and may request to take possession of the animal. Notification should 
be given to the appropriate Service Regional Law Enforcement Office or 
associated management office. Information on the offices to contact is 
set forth under Regulation Promulgation, below. Law enforcement offices 
must be notified within 72 hours of the death, unless special 
conditions warrant an extension. The Service may allow additional 
reasonable time for reporting if access to these offices is limited due 
to closure or if the activity was conducted in area without sufficient 
communication access.

Permits

    We may issue permits to carry out otherwise prohibited activities, 
including those described above, involving threatened wildlife under 
certain circumstances. Regulations governing permits are codified at 50 
CFR 17.32. With regard to threatened wildlife, a permit may be issued 
for the following purposes: Scientific purposes, to enhance propagation 
or survival, for economic hardship, for zoological exhibition, for 
educational purposes, for incidental taking, or for special purposes 
consistent with the purposes of the Act. There are also certain 
statutory exemptions from the prohibitions, which are found in sections 
9 and 10 of the Act.
    This 4(d) rule would not impact existing or future permits issued 
by the Service for take of humpback chub. Any person with a valid 
permit issued by the Service under Sec.  17.22 or Sec.  17.32 may take 
humpback chub, subject to all take limitations and other special terms 
and conditions of the permit.
    Nothing in this 4(d) rule changes in any way the recovery planning 
provisions of section 4(f) of the Act, the consultation requirements 
under section 7 of the Act, or our ability to enter into partnerships 
for the management and protection of the humpback chub. However, 
interagency cooperation may be further streamlined through planned 
programmatic consultations for the species between us and other Federal 
agencies, where appropriate.

Required Determinations

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be 
prepared in connection with determining a species' listing status under 
the Endangered Species Act. We published a notice outlining our reasons 
for this determination in the Federal Register on October 25, 1983 (48 
FR 49244). We also determine that 4(d) rules that accompany regulations 
adopted pursuant to section 4(a) of the Act are not subject to the 
National Environmental Policy Act.

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), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial 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. We coordinated with Tribes in the 
range of the humpback chub and requested their input on this rule. On 
July 2, 2020, we conducted government-to-government consultation with 
the Navajo Nation regarding this rule.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at https://www.regulations.gov at Docket No. FWS-R6-ES-
2018-0081, and upon request from the Upper Colorado River Endangered 
Fish Recovery Program Office (see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this final rule are staff members of the 
Upper Colorado River Endangered Fish Recovery Program Office.

List of Subjects in 50 CFR Part 17

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

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; and 4201-4245, 
unless otherwise noted.

0
2. Amend Sec.  17.11(h) by revising the entry for ``Chub, humpback'' 
under Fishes on the List of Endangered and Threatened Wildlife to read 
as follows:


Sec.  17.11   Endangered and threatened wildlife.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                           Listing citations and
          Common name             Scientific name      Where listed          Status          applicable rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
Fishes
 

[[Page 57609]]

 
                                                  * * * * * * *
Chub, humpback.................  Gila cypha.......  Wherever found...  T................  32 FR 4001, 3/11/1967;
                                                                                          86 FR [INSERT Federal
                                                                                           Register  PAGE WHERE
                                                                                           THE DOCUMENT BEGINS];
                                                                                           10/18/2021; 50 CFR
                                                                                           17.44(dd); \4d\ 50
                                                                                           CFR 17.95(e).\CH\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


0
3. Amend Sec.  17.44 by adding paragraph (dd) to read as follows:


Sec.  17.44   Special rules--fishes.

* * * * *
    (dd) Humpback chub (Gila cypha). (1) Prohibitions. The following 
prohibitions that apply to endangered wildlife also apply to humpback 
chub. Except as provided under paragraphs (dd)(2) and (3) of this 
section and Sec. Sec.  17.4 and 17.5, it is unlawful for any person 
subject to the jurisdiction of the United States to commit, to attempt 
to commit, to solicit another to commit, or cause to be committed, any 
of the following acts in regard to this species:
    (i) Import or export, as set forth at Sec.  17.21(b) for endangered 
wildlife.
    (ii) Take, unless excepted as outlined in paragraphs (dd)(2)(i) 
through (v) of this section.
    (iii) Possession and other acts with unlawfully taken specimens, as 
set forth at Sec.  17.21(d)(1) for endangered wildlife.
    (iv) Interstate or foreign commerce in the course of commercial 
activity, as set forth at Sec.  17.21(e) for endangered wildlife.
    (v) Sale or offer for sale, as set forth at Sec.  17.21(f) for 
endangered wildlife.
    (2) General exceptions from prohibitions. In regard to this 
species, you may:
    (i) Conduct activities as authorized by an existing permit under 
Sec.  17.32.
    (ii) Conduct activities as authorized by a permit issued prior to 
November 17, 2021 under Sec.  17.22 for the duration of the permit.
    (iii) Take, as set forth at Sec.  17.21(c)(2) through (c)(4) for 
endangered wildlife.
    (iv) Take, as set forth at Sec.  17.31(b).
    (v) Possess and engage in other acts with unlawfully taken 
specimens, as set forth at Sec.  17.21(d)(2) for endangered wildlife.
    (3) Exceptions from prohibitions for specific types of incidental 
take. You may take humpback chub while carrying out the following 
legally conducted activities in accordance with this paragraph (dd)(3):
    (i) Definitions. For the purposes of this paragraph (dd)(3):
    (A) Qualified person means a full-time fish biologist or aquatic 
resources manager employed by any of the Colorado River Basin State 
wildlife agencies, Native American Tribes, the Department of the 
Interior bureaus and offices located within the Colorado River basin, 
or fish biologist or aquatic resource manager employed by a private 
consulting firm, provided the firm has received a scientific collecting 
permit from the appropriate State agency.
    (B) The six core populations means the following populations of the 
humpback chub: Desolation and Gray Canyons (Green River, Utah), 
Dinosaur National Monument (Green and Yampa Rivers, Colorado and Utah), 
Black Rocks (Colorado River, Colorado), Westwater Canyon (Colorado 
River, Utah), Cataract Canyon (Colorado River, Utah), and Grand Canyon 
(Colorado and Little Colorado Rivers, Arizona).
    (C) Reasonable care means limiting the impacts to humpback chub 
individuals and populations by complying with all applicable Federal, 
State, and Tribal regulations for the activity in question; using 
methods and techniques that result in the least harm, injury, or death, 
as feasible; undertaking activities at the least impactful times and 
locations, as feasible; and protecting existing extant wild populations 
of humpback chub by ensuring minimal impacts from the removal or 
sampling of individuals, preventing the introduction of disease or 
parasites, and preserving genetic diversity.
    (ii) Creation and maintenance of refuge populations. A qualified 
person may take humpback chub in order to create or maintain a captive 
or wild refuge population that protects the long-term genetic diversity 
of humpback chub, provided that reasonable care is practiced to 
minimize the effects of that taking.
    (A) Methods of allowable take under this paragraph (dd)(3)(ii) 
include, but are not limited to:
    (1) Removing wild individuals via electrofishing, nets, and seines 
from the six core populations;
    (2) Managing captive populations, including handling, rearing, and 
spawning of captive fish;
    (3) Sacrificing individuals for hatchery management, such as 
parasite and disease certification; and
    (4) Eliminating wild refuge populations if conditions are deemed 
inadequate for conservation of the species or are deemed detrimental to 
the six core populations.
    (B) Before the establishment of any captive or wild refuge 
population, the Service must approve, in writing, the designation of 
the refuge population, and any removal of humpback chub individuals 
from wild populations. Subsequent to a written approval for the 
establishment of a refuge population, take associated with the 
maintenance of the refuge population would not be prohibited under the 
Act.
    (iii) Translocation and stocking of humpback chub. A qualified 
person may take humpback chub in order to introduce individuals into 
areas outside of the six core populations. Humpback chub individuals 
may be introduced to new areas by translocating wild individuals to 
additional locations or by stocking individuals from captivity. All 
translocations of wild individuals and stocking of individuals from 
captivity must involve reasonable care to minimize the effects of that 
taking. Translocations of wild individuals and stocking of individuals 
from captivity must be undertaken to expand the range of humpback chub 
or to supplement existing populations.
    (A) Methods of allowable take under this paragraph (dd)(3)(iii) 
include, but are not limited to:
    (1) Removing wild individuals via electrofishing, nets, and seines;
    (2) Managing captive populations, including handling, rearing, and 
spawning;
    (3) Sacrificing individuals for hatchery management, such as 
parasite and disease certification; and
    (4) Removing or eliminating all humpback chub from failed 
introduction areas via mechanical or chemical methods.
    (B) The Service must approve, in advance and in writing:
    (1) Any translocation program; and
    (2) Any stocking of humpback chub into any of the six core 
populations.

[[Page 57610]]

    (iv) Nonnative fish removal. A qualified person may take humpback 
chub in order to perform nonnative fish removal for conservation 
purposes if reasonable care is practiced to minimize effects to 
humpback chub. For this paragraph (dd)(3)(iv), nonnative fish removal 
for conservation purposes means any action with the primary or 
secondary purpose of mechanically removing nonnative fishes that 
compete with, predate, or degrade the habitat of humpback chub.
    (A) Methods of allowable take under this paragraph (dd)(3)(iv) 
include, but are not limited to:
    (1) Mechanical removal of nonnative fish within occupied humpback 
chub habitats, including, but not limited to, electrofishing, seining, 
netting, and angling; and
    (2) The use of other ecosystem modifications, such as altered flow 
regimes or habitat modifications.
    (B) The Service and all applicable landowners must approve, in 
advance and in writing, any nonnative fish removal activities under 
this paragraph (dd)(3)(iv).
    (v) Catch-and-release angling of humpback chub. States and Tribes 
may enact Federal, State, and Tribal fishing regulations that address 
catch-and-release angling.
    (A) In the six core populations, angling activities may include 
nontargeted (incidental) catch and release of humpback chub when 
targeting other species in accordance with Federal, State, and Tribal 
fishing regulations.
    (B) In areas outside of the six core populations, angling 
activities may include targeted catch and release of humpback chub in 
accordance with Federal, State, and Tribal fishing regulations.
    (C) Angling activities may cause take via:
    (1) Handling of humpback chub caught via angling;
    (2) Injury to humpback chub caught via angling; and
    (3) Unintentional death to humpback chub caught via angling.
    (D) Reasonable consideration by the Federal, State, and Tribal 
agencies for incidental catch and release of humpback chub in the six 
core populations include:
    (1) Regulating tactics to minimize potential injury and death to 
humpback chub if caught;
    (2) Communicating the potential for catching humpback chub in these 
areas; and
    (3) Promoting the importance of the six core populations.
    (E) Reasonable consideration for establishing new recreational 
angling locations for humpback chub include, but are not limited to:
    (1) Evaluating each water body's ability to support humpback chub 
and sustain angling;
    (2) Ensuring the recreational fishing population does not 
detrimentally impact the six core populations of humpback chub through 
such factors as disease or genetic drift; and
    (3) Monitoring to ensure there are no detrimental effects to the 
humpback chub population from angling.
    (F) The Service and all applicable State, Federal, and Tribal 
landowners must approve, in advance and in writing, any new 
recreational fishery for humpback chub.
    (vi) Chemical treatments to support humpback chub. A qualified 
person may take humpback chub by performing a chemical treatment in 
accordance with Federal, State, and Tribal regulations that would 
support the conservation and recovery of humpback chub, provided that 
reasonable care is practiced to minimize the effects of such taking.
    (A) For treatments upstream of occupied humpback chub habitat:
    (1) Service approval is not required; and
    (2) Care should be taken to limit the potential for fish toxicants 
and piscicides traveling beyond treatment boundaries and impacting 
humpback chub.
    (B) For treatments in known or potentially occupied humpback chub 
habitat:
    (1) The Service must approve, in advance and in writing, any 
treatment;
    (2) Care should be taken to perform robust salvage efforts to 
remove any humpback chub that may occur in the treatment area before 
the treatment is conducted; and
    (C) Whenever possible, humpback chub that are salvaged should be 
moved to a location that supports recovery of the species.
    (vii) Reporting and disposal requirements. Any mortality of 
humpback chub associated with the actions authorized under the 
regulations in this paragraph (dd)(3) must be reported to the Service 
within 72 hours, and specimens may be disposed of only in accordance 
with directions from the Service. Reports in the upper basin (upstream 
of Glen Canyon Dam) must be made to the Service's Mountain-Prairie 
Region Law Enforcement Office, or the Service's Upper Colorado River 
Endangered Fish Recovery Office. Reports in the lower basin (downstream 
Glen Canyon Dam) must be made to the Service's Southwest Region Law 
Enforcement Office, or the Service's Arizona Fish and Wildlife 
Conservation Office. Contact information for the Service's regional 
offices is set forth at 50 CFR 2.2, and the phone numbers of Law 
Enforcement offices are at 50 CFR 10.22. The Service may allow 
additional reasonable time for reporting if access to these offices is 
limited due to office closure or if the activity was conducted in an 
area without sufficient communication access.
* * * * *

Martha Williams,
Principal Deputy Director, Exercising the Delegated Authority of the 
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2021-20964 Filed 10-15-21; 8:45 am]
BILLING CODE 4333-15-P