Endangered and Threatened Wildlife and Plants; Threatened Species Status With Section 4(d) Rule for Pecos Pupfish and Designation of Critical Habitat, 92744-92785 [2024-27127]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 89, Number 226 (Friday, November 22, 2024)]
[Proposed Rules]
[Pages 92744-92785]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27127]



[[Page 92743]]

Vol. 89

Friday,

No. 226

November 22, 2024

Part II





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Threatened Species 
Status With Section 4(d) Rule for Pecos Pupfish and Designation of 
Critical Habitat; Proposed Rule

Federal Register / Vol. 89 , No. 226 / Friday, November 22, 2024 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2024-0143; FXES1111090FEDR-256-FF09E21000]
RIN 1018-BH76


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status With Section 4(d) Rule for Pecos Pupfish and Designation of 
Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the Pecos pupfish (Cyprinodon pecosensis), a fish species from the 
Pecos River Basin of New Mexico and Texas, as a threatened species and 
designate critical habitat under the Endangered Species Act of 1973, as 
amended (Act). This determination also serves as our 12-month finding 
on a petition to list the Pecos pupfish. After a review of the best 
available scientific and commercial information, we find that listing 
the species is warranted. Accordingly, we propose to list the Pecos 
pupfish as a threatened species with a rule issued under section 4(d) 
of the Act (``4(d) rule''). If we finalize this rule as proposed, the 
Pecos pupfish would be added to the List of Endangered and Threatened 
Wildlife and the Act's protections would be extended to the species. We 
also propose to designate critical habitat for the Pecos pupfish under 
the Act. In total, 136.12 river miles (219.06 river kilometers) and 
26,555.54 acres (10,746.64 hectares) in Chaves and Eddy Counties, New 
Mexico, and Culberson and Reeves Counties, Texas, fall within the 
boundaries of the proposed critical habitat designation. We also 
announce the availability of an economic analysis of the proposed 
designation of critical habitat for Pecos pupfish.

DATES: We will accept comments received or postmarked on or before 
January 21, 2025. We must receive requests for a public hearing, in 
writing, at the address shown in FOR FURTHER INFORMATION CONTACT, by 
January 6, 2025.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R2-ES-2024-0143, 
which is the docket number for this rulemaking. Then, click on the 
Search button. On the resulting page, in the panel on the left side of 
the screen, under the Document Type heading, check the Proposed Rule 
box to locate this document. You may submit a comment by clicking on 
``Comment.'' Comments submitted electronically using the Federal 
eRulemaking Portal must be received by 11:59 p.m. eastern time on the 
closing date.
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R2-ES-2024-0143, U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Information Requested, below, for more information).
    Availability of supporting materials: Supporting materials, such as 
the species status assessment report, are available on the Service's 
website at https://www.fws.gov/office/new-mexico-ecological-services, 
at https://www.regulations.gov at Docket No. FWS-R2-ES-2024-0143, or 
both. If we finalize the critical habitat designation, we will make the 
coordinates or plot points or both from which the maps are generated 
available at https://www.regulations.gov at Docket No. FWS-R2-ES-2024-
0143 and on the Service's website at https://www.fws.gov/office/new-mexico-ecological-services.

FOR FURTHER INFORMATION CONTACT: Shawn Sartorius, Field Supervisor, 
U.S. Fish and Wildlife Service, New Mexico Ecological Services Field 
Office, 2105 Osuna NE, Albuquerque, NM 87113; telephone 505-697-7606. 
Individuals in the United States who are deaf, deafblind, hard of 
hearing, or have a speech disability may dial 711 (TTY, TDD, or 
TeleBraille) to access telecommunications relay services. Individuals 
outside the United States should use the relay services offered within 
their country to make international calls to the point-of-contact in 
the United States. Please see Docket No. FWS-R2-ES-2024-0143 on https://www.regulations.gov for a document that summarizes this proposed rule.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Act, a species warrants 
listing if it meets the definition of an endangered species (in danger 
of extinction throughout all or a significant portion of its range) or 
a threatened species (likely to become an endangered species within the 
foreseeable future throughout all or a significant portion of its 
range). If we determine that a species warrants listing, we must list 
the species promptly and designate the species' critical habitat to the 
maximum extent prudent and determinable. We have determined that the 
Pecos pupfish meets the definition of a threatened species; therefore, 
we are proposing to list it as such, and we are proposing a designation 
of its critical habitat. Both listing a species as an endangered or 
threatened species and making a critical habitat designation can be 
completed only by issuing a rule through the Administrative Procedure 
Act rulemaking process (5 U.S.C. 551 et seq.).
    What this document does. We propose to list the Pecos as a 
threatened species with a rule issued under section 4(d) of the Act, 
and we propose the designation of critical habitat for the species
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that Pecos pupfish meets the 
definition of a threatened species due to the following threats: (1) 
introgression of the sheepshead minnow (Cyprinodon variegatus) (Factor 
E), (2) the loss and decline of surface and ground waters (Factor A), 
(3) degradation of water quality (Factor A), and (4) habitat loss and 
fragmentation (Factor A), all of which are exacerbated by the ongoing 
and expected effects of climate change (Factor E).
    Section 4(a)(3) of the Act requires that the Secretary of the 
Interior (Secretary), to the maximum extent prudent and determinable, 
concurrently with listing, designate critical habitat for the species. 
Section 3(5)(A) of the Act defines critical habitat as (i) the specific 
areas within the geographical area occupied by the species, at the time 
it is listed, on which are found those physical or biological features 
(I) essential to the conservation of the species and (II) which may 
require special management considerations or protections; and (ii) 
specific areas outside the geographical

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area occupied by the species at the time it is listed, upon a 
determination by the Secretary that such areas are essential for the 
conservation of the species. Section 4(b)(2) of the Act states that the 
Secretary must make the designation on the basis of the best scientific 
data available and after taking into consideration the economic impact, 
the impact on national security, and any other relevant impacts of 
specifying any particular area as critical habitat.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other governmental agencies, Native 
American Tribes, the scientific community, industry, or any other 
interested parties concerning this proposed rule. We particularly seek 
comments concerning:
    (1) The species' biology, range, and population trends, including:
    (a) Biological or ecological requirements of the species, including 
habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns 
and the locations of any additional populations of this species;
    (d) Historical and current population levels, and current and 
projected trends; and
    (e) Past and ongoing conservation measures for the species, its 
habitat, or both.
    (2) Threats and conservation actions affecting the species, 
including:
    (a) Factors that may be affecting the continued existence of the 
species, which may include habitat modification or destruction, 
overutilization, disease, predation, the inadequacy of existing 
regulatory mechanisms, or other natural or manmade factors.
    (b) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species.
    (c) Existing regulations or conservation actions that may be 
addressing threats to this species.
    (3) Additional information concerning the historical and current 
status of this species.
    (4) Information to assist with applying or issuing protective 
regulations under section 4(d) of the Act that may be necessary and 
advisable to provide for the conservation of the Pecos pupfish. In 
particular, information concerning:
    (a) The extent to which we should include any of the Act's section 
9 prohibitions in the proposed 4(d) rule; or
    (b) Whether we should consider any additional or different 
exceptions from the prohibitions in the proposed 4(d) rule.
    (5) Specific information related to critical habitat, such as:
    (a) The amount and distribution of Pecos pupfish habitat;
    (b) Any additional areas occurring within the range of the species, 
Chaves and Eddy Counties, New Mexico, and Culberson and Reeves 
Counties, Texas, that should be included in the designation because 
they (i) are occupied at the time of listing and contain the physical 
or biological features that are essential to the conservation of the 
species and that may require special management considerations or 
protection, or (ii) are unoccupied at the time of listing and are 
essential for the conservation of the species; and
    (c) Special management considerations or protection that may be 
needed in critical habitat areas we are proposing, including managing 
for the potential effects of climate change.
    (6) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat.
    (7) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
designation, and the related benefits of including or excluding 
specific areas.
    (8) Information on the extent to which the description of probable 
economic impacts in the economic analysis is a reasonable estimate of 
the likely economic impacts and the description of the environmental 
impacts in the environmental assessment is complete and accurate and 
any additional information regarding probable economic impacts that we 
should consider.
    (9) Whether any specific areas we are proposing for critical 
habitat designation should be considered for exclusion under section 
4(b)(2) of the Act, and whether the benefits of potentially excluding 
any specific area outweigh the benefits of including that area, in 
particular for those covered by the Pecos Pupfish Conservation 
Agreement (see more details in Conservation Efforts and Regulatory 
Mechanisms below). If you think we should exclude any additional areas, 
please provide information supporting a benefit of exclusion.
    (10) Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Please note that submissions merely stating support for, or 
opposition to, the action under consideration without providing 
supporting information, although noted, do not provide substantial 
information necessary to support a determination. Section 4(b)(1)(A) of 
the Act directs that determinations as to whether any species is an 
endangered or a threatened species must be made solely on the basis of 
the best scientific and commercial data available, and section 4(b)(2) 
of the Act directs that the Secretary shall designate critical habitat 
on the basis of the best scientific data available.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the website. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov.
    Our final determination may differ from this proposal because we 
will consider all comments we receive during the comment period as well 
as any information that may become available after this proposal. Based 
on the new information we receive (and, if relevant, any comments on 
that new information), we may conclude that the species is endangered 
instead of threatened, or we may conclude that the species does not 
warrant listing as either an endangered species or a threatened 
species. For critical habitat, our final designation may not include 
all areas proposed, may include some additional areas that meet the 
definition of critical habitat, or may exclude some areas if we find 
the benefits of exclusion outweigh

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the benefits of inclusion and exclusion will not result in the 
extinction of the species. In addition, we may change the parameters of 
the prohibitions or the exceptions to those prohibitions in the 
protective regulations under section 4(d) of the Act if we conclude it 
is appropriate in light of comments and new information received. For 
example, we may expand the prohibitions if we conclude that the 
protective regulation as a whole, including those additional 
prohibitions, is necessary and advisable to provide for the 
conservation of the species. Conversely, we may establish additional or 
different exceptions to the prohibitions in the final rule if we 
conclude that the activities would facilitate or are compatible with 
the conservation and recovery of the species. In our final rule, we 
will clearly explain our rationale and the basis for our final 
decision, including why we made changes, if any, that differ from this 
proposal.

Public Hearing

    Section 4(b)(5) of the Act provides for a public hearing on this 
proposal, if requested. Requests must be received by the date specified 
in DATES. Such requests must be sent to the address shown in FOR 
FURTHER INFORMATION CONTACT. We will schedule a public hearing on this 
proposal, if requested, and announce the date, time, and place of the 
hearing, as well as how to obtain reasonable accommodations, in the 
Federal Register and local newspapers at least 15 days before the 
hearing. We may hold the public hearing in person or virtually via 
webinar. We will announce any public hearing on our website, in 
addition to the Federal Register. The use of virtual public hearings is 
consistent with our regulations at 50 CFR 424.16(c)(3).

Previous Federal Actions

    We identified the Pecos pupfish as a Category 2 candidate in both 
the December 30, 1982, Review of Vertebrate Wildlife, Notice of Review 
(47 FR 58454); and the September 18, 1985, Review of Vertebrate 
Wildlife, Notice of Review (50 FR 37958). Category 2 candidates were 
those species for which the Service had information that proposed 
listing was possibly appropriate, but conclusive data on biological 
vulnerability and threats were not available to support a proposed rule 
at the time. This situation changed when the Pecos pupfish was 
identified as a Category 1 candidate in the January 6, 1989, Animal 
Notice of Review (54 FR 554) and in the November 21, 1991, Animal 
Notice of Review (56 FR 58804). Category 1 candidates were those 
species for which the Service had on file sufficient information to 
support issuance of proposed listing rules. In the February 28, 1996, 
Candidate Notice of Review (61 FR 7596), we discontinued the 
designation of multiple categories of candidates, and only former 
Category 1 species are now recognized as candidates for listing 
purposes. The Pecos pupfish remained a candidate species in the 1996 
Notice of Review and also in the September 19, 1997, Notice of Review 
(62 FR 49398).
    The Pecos pupfish was proposed for listing as an endangered species 
without critical habitat on January 30, 1998 (63 FR 4608). Within the 
ensuing year between the proposal of the species for listing and the 
required final determination, a conservation agreement was developed. 
The conservation agreement was cited in the March 17, 2000, withdrawal 
of the proposed rule to list (65 FR 14513) as sufficient to ensure the 
viability of the Pecos pupfish.
    On June 18, 2007, we were petitioned to list the Pecos pupfish as 
an endangered species as part of a multi-species petition to list 475 
species in the Service's Southwest Region by WildEarth Guardians (WEG, 
formerly Forest Guardians). On December 16, 2009, we issued a positive 
90-day finding that the petition presented information indicating that 
the listing of the Pecos pupfish may be warranted (74 FR 66866) and 
initiated a status review. Per a court-approved settlement agreement, 
we agreed to send a 12-month petition finding for the Pecos pupfish to 
the Federal Register by December 1, 2024.

Peer Review

    A species status assessment (SSA) team prepared an SSA report for 
the Pecos pupfish. 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 in our August 22, 
2016, memorandum updating and clarifying the role of peer review in 
listing and recovery actions under the Act (https://www.fws.gov/sites/default/files/documents/peer-review-policy-directors-memo-2016-08-22.pdf), we solicited independent scientific review of the information 
contained in the Pecos pupfish SSA report. We sent the SSA report to 
four independent peer reviewers and received four responses. Results of 
this structured peer review process can be found at https://www.regulations.gov and https://www.fws.gov/office/new-mexico-ecological-services. In preparing this proposed rule, we incorporated 
the results of these reviews, as appropriate, into the SSA report, 
which is the foundation for this proposed rule.

Summary of Peer Reviewer Comments

    As discussed in Peer Review above, we received comments from four 
peer reviewers on the draft SSA report. We reviewed all comments we 
received from the peer reviewers for substantive issues and new 
information regarding the contents of the SSA report. The peer 
reviewers generally concurred with our methods and conclusions and 
provided additional information, clarifications, and suggestions, 
including clarifications in terminology, additional literature on 
habitat fragmentation, discussions of severity of threats, and other 
editorial suggestions. Otherwise, no substantive changes to our 
analysis and conclusions within the SSA report were deemed necessary, 
and peer reviewer comments are addressed in version 1.2 of the SSA 
report (Service 2024, entire).

I. Proposed Listing Determination

Background

    A thorough review of the taxonomy, life history, and ecology of the 
Pecos pupfish is presented in the SSA report (version 1.2; Service 
2024, pp. 1-21). The following sections are a synopsis of that 
information.
    The Pecos pupfish is a small, deep-bodied (28 to 46 millimeter (mm) 
(1.1 to 1.8 inch (in.)), freshwater fish from the Pecos River Basin of 
New Mexico and Texas. It occurs in a variety of aquatic environments 
including wetlands, sinkholes, waterfowl impoundments, streams, springs 
and the Pecos River mainstem. The species historically inhabited the 
upper, middle, and lower Pecos River from just above Bitter Lake 
National Wildlife Refuge (NWR), Chaves County, NM, in the north, to 
south of the mouth of Independence Creek, in Crockett and Terrell 
Counties, TX, in the south. The Pecos pupfish is a member of the 
Cyprinodontidae family (pupfish and killifish), a group that includes 9 
genera, 115 species, and 8 subspecies (ITIS 2023, entire). It is 
recognized as a valid taxon by the American Fisheries Society, and the 
Service accepts this taxonomy.

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    The Pecos pupfish varies in body color from gray to brown to 
iridescent blue. Pecos pupfish vary phenotypically amongst isolated 
habitat types, which may be advantageous for adapting to different food 
availability, dissolved oxygen availability, and salinity levels 
(Collyer et al. 2015, entire; Xu 2017, p. 22). Pecos pupfish are 
opportunistic omnivores; their diet is primarily composed of a diatom-
detritus mixture, but may also include animal material, filamentous 
algae, macrophytes, sand, and seeds (Davis 1981, p. 536).
    Pupfish are a euryhaline group of fish and are able to withstand 
conditions such as elevated salinity, higher water temperatures, and 
lower dissolved oxygen, that many other fish cannot tolerate (Kodric-
Brown 1975, pp. 3, 6). The Pecos pupfish occurs in a variety of aquatic 
environments including wetlands, sinkholes, waterfowl impoundments, 
streams, springs, and the Pecos River mainstem (Hoagstrom and Brooks 
1999, pp. 14-16; Collyer et al. 2015, p. 182). Pecos pupfish prefer 
environments with little to no water flow, and, in areas with flows, 
they typically occupy pools and shallow runs and riffles (Hoagstrom and 
Brooks 1999, pp. 36, 45). Within their occupied habitat, Pecos pupfish 
require a diverse set of microscale habitat conditions. A variety of 
underwater features such as crevices, boulders, large rocks, scattered 
pebbles, and aquatic plants provide topographic diversity throughout 
the range of the Pecos pupfish (Kodric-Brown 1975, p. 35; 1977, pp. 
750-751, 753-756, and 761-762).
    Pecos pupfish are sexually mature at 20 mm (0.79 in), within a few 
months of hatching (Kodric-Brown 1983, p. 128). Female Pecos pupfish 
lay an average of 10 eggs per day that adhere to spawning substrate, 
such as vegetation or rocks (Kodric-Brown 1977, pp. 751, 761-762, 764; 
(Garrett 1982, pp. 360, 363; Farrington and Brandenburg 2003, p. 1). 
Spawning occurs May through September, peaking in late June through 
July when water temperatures consistently exceed 30 degrees Celsius 
([deg]C) (86 degrees Fahrenheit ([deg]F)) in shallow waters less than 2 
meters (m) (6.56 feet (ft)) deep, and in areas with a variety of silt-
free underwater features such as crevices, boulders, large rocks, 
scattered pebbles, and aquatic plants (Kodric-Brown 1975, p. 35; 1977, 
pp. 750-751, 753-756, and 761-762). Pecos pupfish generally live for 1 
year but can live an average of 2.5 years in captivity (Kodric-Brown 
1977, p. 752m 765; Doege 2023, entire).

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and the implementing 
regulations in title 50 of the Code of Federal Regulations set forth 
the procedures for determining whether a species is an endangered 
species or a threatened species, issuing protective regulations for 
threatened species, and designating critical habitat for endangered and 
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 use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the species' expected response and 
the effects of the threats--in light of those actions and conditions 
that will ameliorate the threats--on an individual, population, and 
species level. We evaluate each threat and its expected effects on the 
species, then analyze the cumulative effect of all of the threats on 
the species as a whole. We also consider the cumulative effect of the 
threats in light of those actions and conditions that will have 
positive effects on the species, such as any existing regulatory 
mechanisms or conservation efforts. The Secretary determines whether 
the species meets the definition of an ``endangered species'' or a 
``threatened species'' only after conducting this cumulative analysis 
and describing the expected effect on the species.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis, which is 
further described in the 2009 Memorandum Opinion on the foreseeable 
future from the Department of the Interior (DOI), Office of the 
Solicitor (M-37021, January 16, 2009; ``M-Opinion,'' available online 
at https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf). The foreseeable future extends as far into the future as 
the U.S. Fish and Wildlife Service and National Marine Fisheries 
Service (hereafter, the Services) can make reasonably reliable 
predictions about the threats to the species and the species' responses 
to those threats. We need not identify the foreseeable future in terms 
of a specific period of time. We will describe the foreseeable future 
on a case-by-case basis, using the best available data and taking into 
account considerations such as the species' life-history 
characteristics, threat-projection timeframes, and environmental 
variability. In other words, the foreseeable future is the period of 
time over which we can make reasonably reliable predictions. 
``Reliable'' does not mean ``certain''; it means sufficient to provide 
a reasonable degree of confidence in the prediction, in light of the 
conservation purposes of the Act.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
threats to the species. The SSA report does not represent our decision 
on

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whether the species should be proposed for listing as an endangered or 
threatened species under the Act. However, it does provide the 
scientific basis that informs our regulatory decisions, which involve 
the further application of standards within the Act and its 
implementing regulations and policies.
    To assess Pecos pupfish viability, we used the three conservation 
biology principles of resiliency, redundancy, and representation 
(Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency is the 
ability of the species to withstand environmental and demographic 
stochasticity (for example, wet or dry, warm or cold years); redundancy 
is the ability of the species to withstand catastrophic events (for 
example, droughts, large pollution events); and representation is the 
ability of the species to adapt to both near-term and long-term changes 
in its physical and biological environment (for example, climate 
conditions, pathogens). In general, species viability will increase 
with increases in resiliency, redundancy, and representation (Smith et 
al. 2018, p. 306). Using these principles, we identified the species' 
ecological requirements for survival and reproduction at the 
individual, population, and species levels, and described the 
beneficial and risk factors influencing the species' viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated 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 sustain populations in the 
wild over time, which we then used to inform our regulatory decision.
    The following is a summary of the key results and conclusions from 
the SSA report; the full SSA report can be found at Docket No. FWS-R2-
ES-2024-0143 on https://www.regulations.gov and at https://www.fws.gov/office/new-mexico-ecological-services.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of the 
species, its resources, and the threats that influence the species' 
current and future condition, in order to assess the species' overall 
viability and the risks to that viability.
    We analyze these factors both individually and cumulatively to 
determine the current condition of the species and project the future 
condition of the species under both plausible future scenarios at mid- 
and late-century.

Species Needs

    For the Pecos pupfish to have sufficient resiliency, redundancy, 
and representation, individuals need suitable habitat that supports 
essential life functions at all life stages (see table 1, below). Based 
upon the best available scientific and commercial information, and 
acknowledging existing ecological uncertainties, the Pecos pupfish 
needs include: (1) adequate population abundance, (2) sufficient water 
quantity, (3) suitable water quality, and (4) habitat diversity.

Table 1--Summary of Pecos Pupfish Individual Environmental Needs by Life
                                  Stage
------------------------------------------------------------------------
               Life stage                  Resource/environmental needs
------------------------------------------------------------------------
Spawning adult.........................   Warm water
                                          temperatures between May and
                                          September.
                                          Suitable oviposition
                                          sites (such as crevices,
                                          boulders, pebbles, scattered
                                          rocks, and subsurface
                                          vegetation mats).
                                          Shallow water less
                                          than 2 m (6.56 ft) deep.
Egg....................................   Salinities greater
                                          than 35,000 milligrams/liter
                                          (mg/L).
Juvenile/non-breeding adults...........   Adequate abundance of
                                          food (algae, insects,
                                          vegetation, etc.).
Overwintering adults and juveniles.....   Dense vegetation.
                                          Deeper water.
All....................................   Hydrologic conditions
                                          conducive to survival
                                          (sufficient water levels,
                                          sufficient water temperature,
                                          etc.).
------------------------------------------------------------------------

Adequate Population Abundance
    Two demographic factors, adult survival and fecundity, influence 
Pecos pupfish population trends and stability (Kodric-Brown and 
Mazzolini 1992, p. 175; Echelle and Connor 1989, p. 725; Echelle et al. 
2003b, entire). The best available information indicates that Pecos 
pupfish can live up to 1 year in the wild and 2.5 years in captivity; 
however, we have no data on egg and juvenile survival (Kodric-Brown 
1977, pp. 756-758; Garrett et al. 2002, p. 366; Doege 2023, entire). 
Data collected annually as part of a 23-year monitoring effort for the 
Pecos Pupfish Conservation Agreement (see more details in Conservation 
Efforts and Regulatory Mechanisms below) have consistently detected 
Pecos pupfish; however, there are typically significant year-to-year 
variations in the number of fish caught at each sampling location (Hatt 
2021, p. 6). To be resilient, populations of Pecos pupfish need to have 
enough individuals (abundance) to withstand stochastic events. 
Additionally, populations need to exist in locations where 
environmental conditions provide suitable habitat and water quality 
such that adequate numbers of individuals can be supported, and where 
there is an absence of sheepshead minnow. Without all these factors, a 
population has an increased likelihood for localized extirpation.
    The sheepshead minnow, once confined to shallow, brackish, coastal 
waters of the Gulf and Atlantic coasts of the continental United 
States, was introduced via a bait-bucket transfer into Red Bluff 
Reservoir near Pecos, Texas, in the early 1980s (Echelle and Connor 
1989, p. 717; Childs et al. 1996, p. 2020;). By the late 1980s, Pecos 
pupfish were extirpated from this area and replaced by the Pecos 
pupfish x sheepshead minnow hybrid (Connor 1987, p. 2; Echelle and 
Connor 1989, pp. 717-720). In 1997, Pecos pupfish x sheepshead minnow 
hybrids were discovered in the Pecos River at Loving Crossing, Eddy 
County, NM (Echelle et al. 1997, p. 338; Echelle and Echelle 2007, p. 
4). Records from 2016 and 2017 indicate that sheepshead minnow likely 
occur as far north as the Brantley Dam, Eddy County, NM, and that non-
introgressed Pecos pupfish are extirpated from the Pecos River below

[[Page 92749]]

Brantley Reservoir, with the exception of the Salt Creek Texas (TX) 
population (Davenport 2023a, entire).
Sufficient Water Quantity
    Pecos pupfish depend on sufficient water quantity to complete all 
stages of their lifecycle. While Pecos pupfish persist in shallow 
habitats less than 1 m (3.3 ft) deep (Salt Creek, NM), they may need 
deeper water to provide thermal refugia and winter habitat (Kodric-
Brown 1977, p. 755). Sufficient water quantity is also necessary 
throughout the year for breeding and adult survival (Kodric-Brown 1977, 
p. 754; Hoagstrom et al. 2015, p. 14). It is surmised that water 
quantity changes in small, ephemeral streams have led to Pecos pupfish 
mortality events in both Bitter Creek and Salt Creek (NM) (Davenport 
2023a and 2023b, entire; Jacobsen 2023, entire; Hoagstrom 2009, p. 28).
    Water quantity for the Pecos pupfish is influenced by a variety of 
factors depending on the specific aquatic environment of a particular 
Pecos pupfish site or population. Sinkhole environments in the Pecos 
Basin are largely spring-fed systems derived from the San Andres 
artesian aquifer (Land 2003, p. 230). Similarly, permanent water in the 
Bitter Creek and Salt Creek (NM) likely originates from spring flow 
from the San Andres aquifer (Land and Huff 2009, p. 1). Salt Creek (TX) 
likely is supported by spring flows from the Toyah Aquifer, though no 
direct modeling has been done on this particular stream (LaFave 1987, 
p. 34). These streams also hold water during precipitation events. 
Water in Bitter Lake NWR is managed through a series of constructed 
impoundments and water conveyance structures. The Bureau of Land 
Management (BLM) Overflow Wetlands are supported by outflows of water 
from Lea Lake, a sinkhole in Bottomless Lakes State Park, as well as 
precipitation. Finally, water in the Pecos River is managed by the 
Bureau of Reclamation (BOR) for water deliveries, environmental flows, 
and fulfilling obligations under the 1948 Pecos River Compact 
(Llewellyn et al. 2021, pp. 39-42).
    Karst aquifer systems, like that found in Bitter Lake NWR, may 
affect sinkhole systems, as groundwater pumping may tap into conduits 
that feed springs or sinkholes (Veni 2013, p. 47). Precipitation cycles 
and agricultural activity appear to be the two main factors causing 
variation in the aquifer levels (Land and Newton 2008, p. 189). 
However, the Roswell Artesian Basin provides an example of a 
rechargeable artesian aquifer, where water reduction measures and high 
levels of rainfall in the 1970's led to a reversal in long-term 
hydraulic head declines and allowed this aquifer to recharge (Land and 
Newton 2008, p. 190).
Suitable Water Quality
    Members of the Cyprinodon genus are known for their wide 
physiological tolerance relative to many other freshwater fishes. Pecos 
pupfish are able to tolerate a wide range of water quality conditions 
(Hoagstrom and Brooks 1999 entire). In areas where the salinity 
gradient changes, Pecos pupfish dominate the areas with the highest 
salinities (Hoagstrom and Brooks 1999 p. 12). However, at salinities 
greater than 35,000 mg/L, larval and egg development are suppressed or 
halted (Hoagstrom and Brooks 1999, p. 21; Propst 1999, p. 67). Pecos 
pupfish can also tolerate low dissolved oxygen for at least short 
periods, with measurements of dissolved oxygen levels as low as 2.5 mg/
L during Pecos pupfish sampling (Hoagstrom and Brooks, 1999, p. 31; 
Propst 1999, pp. 67-68). These tolerance limits are further supported 
by extremes of temperature, dissolved oxygen, and salinity, often 
resulting in pupfish mortality (Hoagstrom and Brooks 1999, p. 21; 
Propst 1999, p. 67). In addition to natural impacts to water quality, 
industrial and agricultural pollutants have been shown to negatively 
impact Pecos pupfish (Houston et al. 2019, p. 33).
Habitat Diversity
    The Pecos pupfish occurs in a variety of aquatic environments with 
a variety of underwater features that provide topographic diversity, 
such as crevices, boulders, large rocks, scattered pebbles, and aquatic 
plants provide topographic diversity throughout the range (Kodric-Brown 
1975, p. 35; 1977, pp. 750-751, 753-756, and 761-762).Pecos pupfish 
typically occupy pools and shallow runs and riffles (Hoagstrom and 
Brooks 1999, pp. 36, 45). For reproduction, Pecos pupfish require 
shallow water less than 2 m (6.56 ft) deep and in areas with 
topographic diversity (Kodric-Brown 1977, pp. 750-751). Rocky 
embankments appear to be the most desirable breeding substrate, as the 
most aggressive and largest males occupy these areas at Mirror Lake, 
Bottomless Lakes State Park, Chaves County, NM (Kodric-Brown 1975, pp. 
34-35). The percentage of males holding territory can vary year to year 
and is influenced by the amount of breeding and foraging habitat 
available (dependent on water levels), and that density of territorial 
males was highest in dense patches of aquatic vegetation, and lowest in 
flat silty areas with isolated rocks (Kodric-Brown 1975, pp. 20, 34-
35). During the colder months when water temperatures drop below 10 
[deg]C (50 [deg]F), Pecos pupfish become inactive and can be found in 
deeper water with dense vegetation and flocculent material (such as 
fine detritus or non-living organic matter) present in the substrate 
(Kodric-Brown 1977, p. 752; Hoagstrom et al. 2015, p. 17).
    For the Pecos pupfish to be resilient, each population needs to be 
able to withstand stochastic events or disturbances that can 
drastically alter local ecosystems. Populations of Pecos pupfish need 
to have enough individuals (abundance) and occupy multiple types of 
habitats with sufficient water quantity and quality, (habitat 
diversity), such as sinkholes, streams, and wetlands to withstand 
stochastic events. Additionally, populations need to exist in locations 
where environmental conditions provide suitable habitat and water 
quality such that adequate numbers of individuals can be supported. 
Without all these factors, a population has an increased likelihood for 
localized extirpation.
    For a species to persist over time, it must exhibit attributes 
across its range that relate to either representation or redundancy. 
Representation describes the ability of a species to adapt to changing 
environmental conditions over time and is characterized by the breadth 
of genetic and environmental diversity within and among populations 
(Shaffer and Stein 2000, p. 308). For the Pecos pupfish to exhibit 
adequate representation, resilient populations should occur within the 
Pecos River Basin to which it is native. The breadth of morphological, 
genetic, and behavioral variation should be preserved to maintain the 
evolutionary variation of the species.
    Redundancy describes the ability of a species to withstand 
catastrophic events (Tear et al. 2005, p. 841; Redford et al. 2011, p. 
42). Adequate redundancy minimizes the effect of localized extirpation 
on the range-wide persistence of a species (Shaffer and Stein 2000, p. 
308). Redundancy for the Pecos pupfish is characterized by having 
multiple, resilient, and representative populations across the range of 
the species. Also important for measuring redundancy is the 
connectivity among discrete populations that allows for immigration and 
emigration between populations and increases the likelihood of 
recolonization should a population become extirpated. In the case of 
the Pecos pupfish, however, increasing connectivity among populations 
can present a hybridization risk.

[[Page 92750]]

Threats

    Following are summary evaluations of four threats analyzed in the 
SSA report for the Pecos pupfish: introgression of the sheepshead 
minnow (Factor E), the loss and decline of surface and ground water, 
degradation of water quality, and habitat loss and fragmentation 
(Factor A), which are exacerbated by the effects of climate change 
(Factor A). We also evaluate existing regulatory mechanisms (Factor D) 
and ongoing conservation measures.
    In the SSA report, we also considered two additional threats: 
golden algal blooms (Factor A) and competition for food resources 
(Factor C). We concluded that, as indicated by the best available 
scientific and commercial information, these threats are currently 
having little to no impact on Pecos pupfish populations and thus the 
overall effect of these threats now and into the future is expected to 
be minimal. Therefore, we will not present summary analyses of those 
threats in this document, but we considered them in the current and 
future condition assessments in the SSA report. For full descriptions 
of all threats and how they impact the species, please see the SSA 
report (Service 2024, pp. 43-44).
Sheepshead Minnow Introgression
    The sheepshead minnow is a threat to the Pecos pupfish through 
hybridization and competition for resources (Echelle et al. 2003b, 
entire; Echelle and Connor 1989, pp. 725-726). Pecos pupfish and 
sheepshead minnow lack isolating mechanisms and readily interbreed, and 
within as few as 5 to 7 years hybridization leads to the complete loss 
of genetically pure (non-introgressed) Pecos pupfish in the area of 
introgression (Cokendolpher 1980, entire; Echelle and Connor 1989, pp. 
725-726; Echelle et al. 2003b, entire; Kodric-Brown and Rosenfield 
2004, entire). Once a population is no longer genetically pure, it no 
longer exists. In addition, research suggests that the hybrid fish grow 
faster and are larger than pure Pecos pupfish, and thus outcompete 
genetically pure Pecos pupfish for resources (Rosenfield et al. 2004, 
p. 1595). Pecos pupfish hybridization with the sheepshead minnow is one 
of the greatest threats to this species and is cited as the cause of 
extirpation from historical sites (Echelle and Connor 1989, pp. 725-
726; Echelle et al. 2003b, entire; Pecos Pupfish Conservation Team 
(Conservation Team) 2022, p. 5).
    The New Mexico State Game Commission and Texas Parks and Wildlife 
Department (TPWD) implemented State fishing regulations that prohibit 
use of sheepshead minnow in the bait harvest and use program since 
1999. However, this nonnative invasive species occurs within the lower 
Pecos River, below the Red Bluff Reservoir, and may be unintentionally 
captured, transferred, and released into Pecos pupfish habitat, and 
thus remains an ongoing threat (Conservation Team 2022, pp. 3, 5). 
While the Red Bluff Reservoir provides a physical barrier that prevents 
sheepshead minnow from naturally moving into the middle Pecos River, 
and the Brantley Dam and Reservoir provide a barrier that prevents the 
sheepshead minnow from naturally moving into the upper Pecos River, 
recreational fishing occurs throughout the river, so it is highly 
likely that a bait-bucket transfer would lead to an introduction of 
sheepshead minnow and result in the introgression of the population of 
Pecos pupfish within the upper Pecos River. Fish barriers have been 
installed at Bitter Lake NWR and at the BLM Overflow Wetlands to 
prevent entrance of sheepshead minnow from the mainstem Pecos River.
Loss and Decline of Surface and Groundwater
    Adverse impacts to both water quantity and, to a lesser extent, 
water quality, are threats to Pecos pupfish viability. As anthropogenic 
uses of water increase from urban, agricultural, and industrial 
development, water management will become more important to maintain 
adequate water for the Pecos pupfish. While the demand on water in the 
Pecos River Basin is expected to increase based on climate change 
projections (Sites Southwest 2008, pp. 6-3, 6-6), we have reasonable 
certainty that there will be adequate aquifer levels until 2100 
(Llewellyn et al. 2021, pp. 99-100). Although diversions from the Pecos 
River are capped by existing water rights, agreements, and regulations, 
decreasing surface water availability can increase the demand for 
pumped ground water (Dunbar et al. 2022, p. 87).
    In New Mexico, population growth in Chaves County, which contains 
the majority of current occupied Pecos pupfish sites, averaged a 1.3 
percent annual growth rate between 1960 and 2010 (Consensus Planning, 
Inc. 2016, p. 10) but a 1.9 percent annual decline between 2010 and 
2020. The Pecos Valley Artesian Conservancy District (PVACD) regulates 
ground water use within the aquifer and supplies water to about 110,000 
acres of crops/year (Llewellyn et al. 2021, p. 47). The amount of water 
withdrawn causes seasonal variability in aquifer levels, but yearly 
fluctuations in ground water levels typically remain similar (PVACD 
2023, entire). The long-term average water level has remained constant. 
Water availability in the Pecos River is influenced by a variety of 
factors including human development, primarily agriculture. However, 
this river is currently managed for multiple uses, including endangered 
species conservation, and future human water use from the river is not 
expected to substantially increase in the future.
    In Texas, the Delaware River, 12 mi (19.31 km) north of Salt Creek 
(TX), is experiencing an increase in ground water pumping to support 
hydraulic fracturing (fracking) operations, and we expect the increased 
water usage to continue around Salt Creek (TX) (Scanlon et al. 2020, 
pp. 3510-3513). Both a deep and shallow aquifer (Rustler and Pecos 
Valley complex) may support the springs feeding Salt Creek (TX) (George 
et al. 2011, pp. 4, 58, 146). However, there are no specific hydrologic 
models detailing how the aquifers influence the flows in Salt Creek 
(TX). Conversely, fracking is not a threat to the Pecos pupfish 
populations in New Mexico as the oil formations there are structured 
differently than those in Texas.
    Water use may increase with a growing human population, potentially 
further depleting ground-water storage and negatively influencing the 
Pecos pupfish's future (Llewellyn et al. 2021, p. 84). Activities such 
as surface and groundwater withdrawals, as well as impoundments, have 
decreased streamflow resulting in direct habitat loss and increased 
habitat fragmentation (Llewellyn et al. 2021, p. 138). Karst aquifer 
systems, like that found on Bitter Lake NWR, may affect sinkhole 
systems, as groundwater pumping may tap into conduits that feed springs 
or sinkholes (Veni 2013, p. 47). Precipitation cycles and agricultural 
activity appear to be the two main factors causing variation in the 
aquifer levels (Land and Newton 2008, p. 189). We are uncertain of how 
the aquifers will be affected and recover (rainfall and recharge), if 
at all, and how reduced surface flows (irrigation) would be affected by 
human population growth (Land and Newton 2008, p. 190).
    The Pecos River provides connected wetted habitat year-round. There 
are four federally owned reservoirs on the Pecos River: Santa Rosa 
(U.S. Army Corps of Engineers (Corps)); Sumner (BOR); Brantley (BOR); 
and Avalon (BOR), and the ground water rights are owned by the NM 
Interstate Stream Commission (Service 2017, pp. 7 and 11). The State 
and Federal agencies

[[Page 92751]]

work together to maintain river flows that provide water for a variety 
of reasons, including environmental reasons. For the last few decades, 
the only releases from Fort Sumner Reservoir to Brantley Reservoir have 
been block releases that occur several times a year at intervals and 
timing contrary to the historical flow regimes, leading to artificially 
low flows (Hoagstrom et al. 2008, p. 6). These block releases manage 
for the threatened Pecos bluntnose shiner (Notropis simus pecosensis) 
and act as a buffer to drying events even though the water may be 
repurposed from environmental use to consumptive irrigation use, and 
will be beneficial to the Pecos pupfish (Hoagstrom et al. 2008, p. 6).
Degradation of Water Quality
    Because Pecos pupfish are relatively tolerant of more extreme water 
quality conditions (high temperatures, low dissolved oxygen, high 
salinity), minor changes to water quality are generally seen as less of 
a concern (Propst 1999, p. 68). However, throughout the Pecos pupfish's 
range, water temperatures have the potential to exceed the fish's 
thermal tolerance (Brown and Feldmeth 1971, entire). Furthermore, it is 
surmised that extreme salinity caused declines in two historical Pecos 
pupfish populations in two springs in Laguna Grande De la Sal, NM 
(Hoagstrom and Brooks 1999, pp. 13-16).
    The entirety of the Pecos pupfish range in the Pecos River has 
ongoing water quality concerns and is considered impaired by the New 
Mexico Environmental Department (Llewellyn et al. 2021, pp. 27-29). 
Below Sumner Reservoir, the river improves for 160 km (100 mi) before 
becoming impaired by nutrients from irrigation return flow, urban 
runoff, and municipal wastewater treatment plant effluent to the State 
line (Llewellyn et al. 2021, pp. 27-28). Another stressor is 
contamination of water by oil and gas development (Bonetti et al. 2021, 
entire). Pipelines present another potential route of contamination, as 
leaks or ruptures may allow oil, gas, or brines to enter underground 
aquifers that contribute to spring flow or by point sources from spills 
and leaks on the surface (Ashworth 1990, p. 31). Oil and brine 
contamination may impair water quality to the extent that Pecos pupfish 
will be unable to carry out metabolic functions (e.g., breathing) 
(Bonetti et al. 2021, p. 4). However, the pipelines in the vicinity of 
Bitter Lake NWR, BLM Area of Critical Environmental Concern (ACEC), and 
Bottomless Lakes State Park are protected and managed to keep these 
systems conserved and free from contamination.
Global Climate Change and Drought
    The Southwest United States is thought to be extremely sensitive to 
increased drought and higher average temperatures caused by climate 
change (Sheffield and Wood 2008, p. 101). In particular, temperatures 
across New Mexico, including in the Pecos River Basin, have risen 
approximately 1.1 [deg]C) (2 ([deg]F) between 1970 and 2020 (Dunbar et 
al. 2022, pp. 4-5). While Pecos pupfish have persisted through 
historical drought conditions, observations from Bitter Lake NWR 
suggest that prolonged drought or higher temperatures have likely led 
to mortality events (Jacobsen 2023, entire). Because Pecos pupfish are 
able to persist in degraded, saline water conditions, they are likely 
to be somewhat resilient to adverse water flow and temperature impacts 
(Propst 1999, pp. 67-68). However, Pecos pupfish are likely persisting 
at or near their thermal maximum, particularly during the hottest parts 
of the year (Matthews and Zimmerman 1990, p. 27). The increasing 
temperatures predicted by climate modeling suggest that water 
temperatures have the potential to exceed the thermal maximum for Pecos 
pupfish (Llewellyn et al. 2021, p. 88). This is particularly crucial 
for sites that are shallower, have limited freshwater input, or are 
isolated from any potential thermal refugia. Observations of the 
Conchos pupfish (C. eximius), a close relative of the pupfish, suggest 
that drought may have caused declines in fish numbers (Davis 1980, p. 
83).
    Climate change manifests in a variety of ways. An average increase 
in temperature manifests itself locally as higher daytime temperatures 
and higher overnight low temperatures (Hayhoe et al. 2018, p. 88). In 
terms of precipitation, broadly speaking, wet areas are expected to get 
wetter and experience more intense precipitation events, while dry 
areas are expected to get drier and experience more intense drought 
events (Shafer et al. 2014, pp. 443-445; Kloesel et al. 2018, pp. 995-
996, 1004). Another effect of climate change is exacerbated drought due 
to feedback loops between high air temperatures, low humidities, and 
low soil moisture (Cheng et al. 2019, pp. 4437-4440). Potential effects 
of climate change that are likely to affect water quality and quantity 
include increased temperatures, evaporation, evapotranspiration, 
drought, earlier runoff, and reduced or increased precipitation 
(Llewellyn et al. 2021, p. 98). The main uncertainty of a changing 
climate is the resulting demands on surface and ground water aquifers 
that support habitat for the Pecos pupfish, thereby reducing water 
quantity and leading to impaired water quality.
Habitat Loss and Fragmentation
    Groundwater depletion has dried up several marshes, playas, and 
spring ponds formerly occupied by Pecos pupfish adjacent to the Pecos 
River in New Mexico and Texas (Hoagstrom and Brooks 1999, p. 11). 
Direct habitat loss was also believed to have caused the extirpation of 
Comanche Springs pupfish (C. elegans) in Texas near Fort Stockton 
(Echelle et al. 2003a, p. 114). Habitat loss occurs when streams are 
dewatered, and surface flow is eliminated. To date, we are unaware of 
habitat loss within the range of the species at a scale that has caused 
the extirpation of Pecos pupfish in an entire population. However, 
significant habitat impairment has occurred throughout the range of the 
Pecos pupfish. For example, the Pecos River has been significantly 
altered through dam construction, channelization, and water diversions 
resulting in the loss of off-channel marshes, oxbows, and changes to 
mainstem flows (Hoagstrom and Brooks 1999, pp. 10-12).
    While we have no data regarding to what extent the Pecos pupfish 
use off-channel marshes and oxbows, based on habitat descriptions of 
the current known occupied locations we presume that at least a portion 
of the available off-channel habitat may have been used by Pecos 
pupfish for connectivity (Hoagstrom and Brooks 1999, p. 22). 
Furthermore, research suggests that habitat fragmentation and 
alteration may have rendered Pecos pupfish populations in the lower 
Pecos River more vulnerable to hybridization with the sheepshead 
minnow, and identified morphological differences between populations 
that are linked to aquatic habitat type and diversity (Collyer et al. 
2015, p. 191). Similarly, pupfish need large and connected populations 
to have a chance to potentially withstand introgression (Collyer et al. 
2015, p. 191). More recently, in 2020, 2022, and 2023, drought events 
led to the loss of portions of Bitter Creek on Bitter Lake NWR, with 
Pecos pupfish mortality observed in 2020 and 2022. Data collected 
during winter surveys suggest that the Pecos pupfish is able to return 
to sections of the creek once sufficient water quantities are present. 
Although data are lacking from the Pecos River mainstem, this scenario 
likely occurs there as well.

[[Page 92752]]

    Habitat fragmentation is the disruption of continuous habitat 
resulting in smaller disconnected areas and can be either temporary or 
permanent (Wiegand et al. 2005, p. 109). The natural landscape for the 
Pecos pupfish comprises isolated sinkholes with unknown subsurface 
connectivity, disjunct wetlands and ephemeral streams, and a 
historically well-connected river system. Much of the direct habitat 
loss and fragmentation within the range of the Pecos pupfish is the 
result of dewatering of habitat as a result of anthropogenic 
development, and water management and use, such as demand for water for 
agriculture and oil and gas development (Hoagstrom et al. 2008, p. 6). 
Climate change impacts in the Pecos River Basin will likely result in 
higher overall surface temperatures. In general, warming surface 
temperatures directly impact evapotranspiration rates and can lead to 
lowered surface water (Llewellyn et al. 2021, p. 21). However, 
throughout the range of the Pecos pupfish the hydrology impacting their 
habitat is a complicated mix of evaporation, spring flow, and 
groundwater recharge.
    The loss of habitat connectivity and the resulting fragmentation 
can lead to isolation among populations, which may have caused a 
genetic bottleneck in some Pecos pupfish populations (Collyer et al. 
2015, p. 191; Whiteley 2023, pp. 6-7). Isolated and small populations 
are also more susceptible to stochastic events and amplify the effects 
of inbreeding depression and genetic drift (Rieman and Allendorf 2001, 
p. 762). Fragmentation and isolation of habitats can increase the risk 
of local extirpation as recolonization from adjacent populations is 
less likely (Hoagstrom et al. 2008, p. 13). As habitat loss and 
fragmentation increases, habitat diversity decreases.
Summary of Threats
    The greatest threats to the Pecos pupfish are introgression with 
sheepshead minnow, loss and decline of surface and ground water, 
degradation of water quality, habitat loss and fragmentation, and the 
effects of climate change. Introduction of sheepshead minnow into new 
locations occupied by Pecos pupfish could lead to rapid introgression, 
replacing the genetically pure population with Pecos pupfish hybrids. 
Research has found Pecos pupfish populations that are already 
negatively impacted by habitat alteration are likely more at risk of 
introgression because the reduction in habitat increases competition 
for breeding substrate (Kodric-Brown and Rosenfield 2004, pp. 121-122; 
Collyer et al. 2015, p. 191). Anthropogenic water use and management 
has impacts on most of the surface water and groundwater within the 
range of the Pecos pupfish, and continued development and climate-
driven changes to water availability will continue to impact the 
species in the future. Climate change impacts including higher average 
annual temperatures, more variable or lower average annual 
precipitation, and increased drought frequency, are currently impacting 
the Pecos pupfish and will likely continue to do so. Increasing 
temperatures increase the risk that shallow habitat could exceed the 
thermal tolerance of Pecos pupfish, and the resulting increased 
evapotranspiration leads to lowering of water levels with the potential 
for corresponding increases in salinity and water temperatures and 
lowered dissolved oxygen.

Conservation Efforts and Regulatory Mechanisms

    In 1999, a conservation agreement was developed to address the 
threats to Pecos pupfish (Conservation Team 1999; entire). Since 
implementation of the conservation agreement, conservation efforts have 
included sheepshead minnow eradication, installation of fish barriers, 
and enforcement of State fishing rules in an effort to protect the 
Pecos pupfish from further introgression of sheepshead minnows or 
hybrids and alleviate other threats affecting the Pecos pupfish 
(Conservation Team 2022, p. 3). The conservation agreement was amended 
in 2013 and in 2022 (Conservation Team 2022, pp. 1, 4).
    These above-mentioned stressors--introgression, water quantity, and 
habitat degradation and loss--have been considered and some have been 
reduced through the implementation of the conservation agreement 
(Conservation Team 2022, entire). The agreement has eight signatory 
agencies: TPWD; New Mexico Department of Game and Fish (NMDGF); New 
Mexico Energy, Minerals, and Natural Resources Department; New Mexico 
Department of Agriculture; New Mexico Interstate Stream Commission; 
Commissioner of Public Lands; New Mexico State Land Office; BLM; and 
the Service (Conservation Team 2022, pp. 8-23). The duration of the 
conservation agreement is indefinite with formal review every 10 years 
(Conservation Team 2022, p. 12).
    Since 1999, one fish barrier has been installed at Bitter Lake NWR, 
near the confluence with the Pecos River. In 2019, two fish barriers 
were replaced at the BLM Overflow Wetlands, where north and south 
concrete barriers were installed to prevent the entrance of fish from 
the mainstem Pecos River into the complex. The barrier on the BLM 
Overflow Wetlands not only protects the wetlands, but also protects the 
Bottomless Lakes complex from the threat of hybridization.
    Moving forward, the conservation agreement will continue to provide 
guidance for agencies and partners working towards Pecos pupfish 
conservation, help provide for ongoing maintenance of fish barriers, 
installation of additional fish barriers, and enforcing existing State 
and Federal baitfish regulations.
    The Fort Worth Zoo and other collaborating zoos have successfully 
bred Pecos pupfish in captivity since 2000. Captive conservation 
efforts have focused on propagation techniques, animal husbandry 
research, and propagation for stocking. Beginning in 2012, the State of 
Texas began working with private landowners within the Pecos River 
watershed to identify opportunities for the development of Pecos 
pupfish production ponds. Two ponds were established in 2024; 
recruitment of additional landowners and establishment of additional 
ponds is ongoing. The goal of the ponds is to sustain the genetic 
lineage from the Salt Creek, TX, population, create stable habitats 
isolated from potential sheepshead minnow incursion with secure water 
sources, and provide a stock of fish that can be used to establish 
other locations.

Current Condition

    A thorough review of the Pecos pupfish's current condition is 
presented in chapter 4 of the SSA report (version 1.2, Service 2024, 
pp. 46-74).
    We divided the Pecos pupfish's range into nine analysis units (AU) 
(Figure 1). Currently, the Pecos pupfish is distributed across seven of 
nine AUs covering the historical range; two of the AUs are considered 
extirpated (figure 1; table 3; Service 2024, figure 20, p. 52). We 
defined Pecos pupfish AUs based on documented occurrences, U.S. 
Geological Survey hydrological unit code (HUC)-12 sub-watershed 
boundaries, stream and river features, and barriers (such as Brantley 
Reservoir and Red Bluff Reservoir) (Service 2024, p, 51). This approach 
is based on the assumption that the closer occurrences are (such as 
within the same AU), the more likely similar environmental processes 
are influencing the sites where the fish occurs. We evaluated the 
current viability of Pecos pupfish using

[[Page 92753]]

population resiliency and species' redundancy and representation.
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[[Page 92754]]

    The species is known from nine analysis units.

              Table 2--Analysis Units for the Pecos Pupfish
------------------------------------------------------------------------
                Analysis unit                        Land ownership
------------------------------------------------------------------------
1: Upper Pecos River.........................  BLM, State, private.
2: Salt Creek Wilderness.....................  FWS.
3: Bitter Creek Drainage.....................  FWS.
4: Bitter Lake NWR Middle Tract Wetlands.....  FWS.
5: Bottomless Lakes State Park...............  State.
6: BLM Overflow Wetlands and Lea Lake........  BLM, State.
7: Middle Pecos River........................  BLM, State, private.
8: Salt Creek (TX)...........................  Private.
9: Lower Pecos River.........................  BLM, State, private.
------------------------------------------------------------------------

    To assess resiliency, we developed a qualitative model that 
incorporates one demographic metric (occurrence) and three habitat 
metrics (water quantity, water quality, and habitat diversity), and 
genetic security into the overall status for each unit (table 3). We 
selected habitat diversity as a metric as habitats with multiple 
aquatic environments may better allow the fish to withstand changing or 
adverse conditions.
    To assess redundancy of the Pecos pupfish, we examined (1) how many 
extant sites exist within each AU, (2) how connected these sites are 
within the unit, and (3) how connected each unit is to nearby units. 
Importantly though, the diversity of the habitat, and not the number of 
sites Pecos pupfish have been detected, reflects the extent of the 
occupied Pecos pupfish habitat within the unit. For example, Bitter 
Creek (on Bitter Lake NWR) is approximately 1,546 m (5,072 ft) of 
variably wetted stream and is counted as a single site. Similarly, the 
BLM Overflow Wetlands cover over 1,000 acres (405 ha) and is also 
counted as a single site. However, we assume that with the exception of 
the sites delineated on the upper Pecos River, which is a riverine 
environment, each site is representative of a discrete aquatic 
environment.
    To assess representation, we used aquatic environment (riverine, 
shallow stream, sinkholes, and wetlands) as a surrogate for genetic 
data. Genetic studies of Pecos pupfish have revealed important genetic 
relationships across the range of the species. The population of Pecos 
pupfish in the upper reaches of Salt Creek (TX) shows a specific allele 
that is unique to this location (Echelle et al. 2003b, p. 6). Recent 
work in the northern portion of their range has found that Pecos 
pupfish populations in the Bottomless Lakes State Park and BLM Overflow 
Wetland (AUs 5 and 6, respectively), are highly genetically 
differentiated from each other and from other populations (Whiteley 
2023, pp. 7-9, 18). Additionally, individuals sampled from Bottomless 
Lakes State Park showed high inbreeding coefficient, (Whiteley 2023, p. 
26). Analysis showed distinct clustering of Pecos pupfish at two sites 
at Bottomless Lakes State Park (Mirror Lake and Lazy Lagoon) and all of 
the sampled sites at Bitter Lake NWR (Whiteley 2023, p. 18). On Bitter 
Lake NWR, two distinct clusters were observed that may indicate gene 
flow (Whiteley 2023, p. 19). The sampled sites in the Middle Tract 
Wetlands clustered with each other and Bitter Creek, while the four 
sample sinkholes all clustered with each other (Whiteley 2023, p. 8). 
While that data analyzed by Whitely (2023, entire) did not attempt to 
infer a relationship between environmental factors, a result that might 
reflect either developmental plasticity or local genetic adaptation, 
research does suggest that Pecos pupfish morphology differs depending 
on the aquatic environments (i.e., habitat diversity) (Echelle and 
Echelle 2007, p. 7; Collyer et al. 2015, p. 187-189; Xu 2017, pp. 22, 
26-27; Whiteley 2023, entire).

                                Table 3--Condition Criteria Resiliency Analysis Metrics as Applied to Each Analysis Unit
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Condition                 Genetic security           Occurrence            Water quantity           Water quality        Habitat diversity
--------------------------------------------------------------------------------------------------------------------------------------------------------
High condition (high resiliency)..  No evidence of          Extant or presumed      Stable and sufficient   No severe impairments   Unit has a diverse
                                     introgression with      extant observed at,     water availability      to water quality        habitat assemblage
                                     sheepshead minnow.      or in the vicinity      throughout the unit.    documented and no       within the unit
                                                             of, each of these       Low flow or drying      recorded                (streams/river,
                                                             sites at least once     events documented,      contamination events.   wetlands, and
                                                             within the last 5       but no long-term                                sinkholes).
                                                             years.                  drying events
                                                                                     recorded.
Moderate condition (moderate        Introgression possible  Two or fewer of the     Occasional low flows    Occasional water        Fish restricted to
 resiliency).                        in the unit, but no     known occupied sites    or drying events        quality impairments     just a single
                                     confirmation.           confirmed or presumed   across <50% of the      documented, likely      habitat type within
                                                             extirpated.             unit with rare long-    linked to low flows.    the unit.
                                                                                     term drying events      No documented
                                                                                     documented.             exposure to surface
                                                                                                             contaminants.
Low condition (low resiliency)....  Introgression only in   Pupfish extant at 50%   Routine low flows and   Documented exposure to  N/A.
                                     a portion of the        or fewer of sites       drying events across    surface contaminants
                                     unit.                   identified.             the majority of the     within much of the
                                                             Populations low         unit and regular long-  unit.
                                                             enough that fish are    term drying events.
                                                             not detected on 50%
                                                             or more visits to
                                                             occupied locations.
Likely extirpated.................  Confirmed               N/A                     N/A                     N/A                     N/A.
                                     introgression
                                     throughout the unit.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 92755]]

    Fundamental to our analysis of the Pecos pupfish was the 
determination of scientifically sound analytical units at a scale 
useful for assessing the species. As there is little information 
available regarding the demographic or genetic processes that define 
the spatial structure of Pecos pupfish populations, we relied on 
spatial occurrence data to define a suitable extent for our AUs. Within 
each AU, we identified discrete sites where Pecos pupfish have been 
documented to occur during past sampling and inventory efforts (Brooks 
1992, entire; Hoagstrom and Brooks 1999, entire; National Heritage New 
Mexico (NHNM) 2021, entire; GBIF 2022, entire). These sites represent 
the documentation of at least one Pecos pupfish at a specific location 
at a point in time. Many of these sites have not been routinely visited 
or have been visited only once. Eleven sampling locations representing 
nine sites have been annually sampled (Hatt 2022, p. 5). In some cases, 
such as sinkholes, these sites are analogous to subpopulations. In 
others, such as the Pecos River or BLM Overflow Wetlands, the 
documented sites represent only the accessible portion of the habitat 
and likely do not represent the entire population in the area.
    Based on the available data and our understanding of Pecos pupfish 
ecology, we developed a basis for assigning a risk category for each 
metric at the population AU level (table 4). The risk category reflects 
a qualitative determination of the likelihood that the species' 
response to the conditions described in each individual metric, over 
the 20-year period following the year 2023, would be extirpated from a 
given population AU. This 20-year timeframe correlates with 
approximately 20 1-year generations, which is near the maximum of the 
presumed Pecos pupfish lifespan in the wild.

 Table 4--Qualitative and Quantitative Descriptions of the Three Risk Categories Used in the Resiliency Analysis
----------------------------------------------------------------------------------------------------------------
                                                        Estimated chance       Numerical
          Risk category              Analysis unit     of extirpation for  extirpation risk        Threats
                                       condition            20 years           estimate        characterization
----------------------------------------------------------------------------------------------------------------
Low risk........................  High condition.....  Extirpation is                  <10%  Threats to pupfish
                                                        very unlikely.                        needs are
                                                                                              minimized or
                                                                                              limited in spatial
                                                                                              extent within the
                                                                                              unit.
Moderate risk...................  Moderate condition.  Extirpation is                10-40%  Threats to pupfish
                                                        unlikely.                             needs are
                                                                                              widespread
                                                                                              throughout the
                                                                                              unit but limited
                                                                                              in duration or
                                                                                              severity.
High risk.......................  Low condition......  Extirpation risk                >40%  Threats to pupfish
                                                        ranges from being                     are severe and
                                                        about as likely                       pervasive
                                                        as not to being                       throughout the
                                                        very likely.                          unit.
----------------------------------------------------------------------------------------------------------------

    We ranked and scored the individual metrics as one (low), two 
(moderate) or three (high), based on criteria described in table 3, 
then combined them to produce a categorical condition score for each 
AU. We then averaged that score across all four categories to develop 
an overall unit score. For the overall unit score, an average of 
greater than 2.6 was considered high condition, 1.6 to 2.5 was 
considered moderate condition, and 1.5 or less was considered low 
condition. To aid in the comparison of AUs (with each other and under 
various future scenarios (see the Future Condition section, below)) and 
assess the species' viability, we categorized the final condition 
scores as ``high'' (population generally secure), ``moderate'' 
(population marginally secure), or ``low'' (population generally 
insecure). We based these categories primarily on our understanding of 
Pecos pupfish habitat needs, known stressors, and the principles of 
conservation biology. We acknowledge that there is uncertainty 
associated with this model and some of the supporting data; however, 
the methodology is appropriate for assessing the status of the Pecos 
pupfish across its range given the best available information.
Resiliency
    Unit 1: Upper Pecos River: Pecos pupfish remain extant in the upper 
Pecos River. Based on their preference for slower, warmer, and more 
saline conditions, and observations from surveys conducted in support 
of other routine fish monitoring, Pecos pupfish are limited to specific 
areas within the upper Pecos River channel and these areas likely shift 
both spatially and temporally. This situation is reflected in data that 
show varying numbers of Pecos pupfish in year-to-year sampling and seem 
to indicate that, during periods of drying, Pecos pupfish are often 
more represented in samples (Davenport 2023b, entire). Although it is 
unclear if any particular site in the upper Pecos River has been lost, 
the highly variable nature of this river section and shifting 
populations likely means that sampling at the same site will not always 
detect the Pecos pupfish.
    The upper Pecos River is subject to regular severe low flows and 
intermittent drying (Follansbee et al. 1915, p. 452; Hatch et al. 1985, 
p. 561; Hoagstrom et al. 2008, p. 6). Because this situation threatens 
the persistence of the federally threatened Pecos bluntnose shiner, 
conservation measures are in place by the BOR through a biological 
opinion (under section 7 of the Act) to minimize intermittent drying. 
These measures buffer the threat of river drying for Pecos bluntnose 
shiner and, by extension, Pecos pupfish. The entire Pecos pupfish range 
in the Pecos River has ongoing water quality concerns and is considered 
impaired due to nutrient loading, discharges from municipal wastewater 
treatment plant discharges, and livestock grazing (Llewellyn et al. 
2021, pp. 28-29). The current condition evaluation for the upper Pecos 
River population determined that occurrence, water quality, and habitat 
diversity are in moderate condition, and water quality is in low 
condition. Thus, the Upper Pecos River population is determined to be 
in overall moderate current condition and has moderate resiliency.
    Unit 2: Salt Creek Wilderness: No routine Pecos pupfish monitoring 
occurs within the Salt Creek Wilderness AU. Pecos pupfish remain extant 
in Salt Creek (NM) and likely at three sinkholes in the unit (Inkpot, 
Little Inkpot, and New Sinkhole). A visit to Salt Creek (NM) in 
February 2023 confirmed presence of the pupfish but also documented a 
mortality event of several thousand mostly juvenile pupfish from an 
undetermined cause (Jacobsen 2023,

[[Page 92756]]

entire). Although Pecos pupfish remain extant at several locations in 
the unit, the habitat available within the unit is small, so this 
stream unit may be subject to mortality events. Pecos pupfish are 
presumed to have been extirpated from Pren's Hole, though the cause is 
unknown (Hatt 2019, p. 5). Pren's Hole seemingly was colonized by a 
flash flood (Hoagstrom and Brooks 1999, p. 16).
    We have no recent data on water quality or quantity within this 
unit from the sinkholes or Salt Creek (NM). Deeper sinkholes generally 
have stable conditions, both in water quantity and quality, and thus we 
assume that likely holds true for the sinkholes in this unit as pupfish 
need large populations and room for expansion (Collyer et al. 2015, p. 
191). Salt Creek (NM) likely experiences routine drying events 
throughout the year, and concurrently with those drying events, 
impairments to temperature, dissolved oxygen, and salinity.
    Though the permanent water in both stream and sinkhole aquatic 
environments is supported by water from the San Andres aquifer, the 
depth of the sinkholes likely provides a more stable long-term 
environment. Conversely, Salt Creek (NM), although more ephemeral, 
allows for Pecos pupfish dispersal throughout the unit and provides a 
potential connection to the Pecos River. This diversity of habitat 
helps buffer the unit against both gradual environmental changes as 
well as stochastic events, such as floods or golden algae, that may 
impact a single aquatic environment. The current condition evaluation 
for the Salt Creek Wilderness determined that habitat diversity is in 
high condition, and occurrence, water quality, and water quantity are 
in moderate condition. Thus, the Salt Creek Wilderness population is 
determined to be in overall moderate current condition and has moderate 
resiliency.
    Unit 3: Bitter Creek Drainage: Routine monitoring occurs in Bitter 
Creek as well as two of the sinkholes in the unit. We extrapolated both 
formal and informal monitoring data to the remainder of the unit, and 
based on habitat availability presumed the Pecos pupfish remains extant 
at all documented occupied sites in the unit. There have been 
documented fish kills on Bitter Creek, but routine monitoring indicates 
that Pecos pupfish populations in the creek remain extant, though 
highly variable (Hatt 2021).
    Water quality is routinely sampled, and no impairments have been 
detected. Much of the water in this unit is derived from underground 
springs from the San Andres aquifer. This includes all of the sinkholes 
as well as the springs that feed Bitter Creek such as the Dragonfly 
Spring and Lost River. The closest monitoring well to this unit shows a 
long-term stable water depth trend that likely corresponds to stable 
spring flows in the unit (Pecos Valley Artesian Conservancy District 
(PVACD) 2023, entire). The water in Bitter Creek is supplemented by 
precipitation. Because evaporation exceeds precipitation across the 
Pecos River Basin, during drought years, portions of Bitter Creek dry 
out (Land 2003, p. 230).
    Though the permanent water in both the stream and sinkhole aquatic 
environments is supported by water from the San Andres aquifer, the 
depth of the sinkholes likely provides a more stable long-term 
environment. Bitter Creek is supported by both seasonal precipitation 
as well as spring flows from Dragonfly Spring and the Lost River. This 
diversity of habitat helps buffer the unit against both gradual 
environmental changes as well as stochastic events, such as floods or 
golden algae, that may impact a single aquatic environment. The Bitter 
Creek Drainage population's current condition evaluation determined 
that occurrence, water quality, and habitat diversity are in high 
condition, and water quality is in moderate condition. Thus, the Bitter 
Creek Drainage population is determined to be in overall high current 
condition and has high resiliency.
    Unit 4: Bitter Creek Middle Tract Wetlands: Pecos pupfish are 
routinely monitored at three sites within the Middle Tract Wetlands AU, 
however, most of the impoundments listed as occupied have not been 
surveyed in decades (Hatt 2022, p. 5). Despite this lack of data, we 
presume that the Pecos pupfish remains extant at all documented 
occupied sites in the unit, due to both their connection to occupied 
habitat and the absence of any known mortality event. While Pecos 
pupfish are not always detected at the monitoring sites during 
consecutive surveys, they have been shown to remain extant within those 
sites (Hatt 2019, p. 5; Hatt 2022, p. 5).
    This unit is composed of artificial wetlands and ditches that are 
managed by Bitter Lake NWR. The ditches are spring fed and retain 
permanent water. The wetland impoundments vary widely in habitat 
extent, and while many are likely to retain permanent water in most 
years, given the variable nature of the water in the impoundments, the 
amount of habitat is presumed to vary widely in any given year, and may 
be extremely limited in particularly dry years.
    There are no known water quality impairments in the unit that would 
impact the Pecos pupfish. When water levels are low, the shallow 
impoundments and wetlands in the unit are subject to adverse water 
quality such as increased temperature and salinity, and decreased 
available dissolved oxygen because water becomes lentic or stagnant and 
soon evaporates.
    Aquatic environments in this unit area are a mix of manmade 
channels, impoundments, and wetlands. While we do not have data on how 
Pecos pupfish move between these environments, the diversity of 
habitats likely helps buffer the Pecos pupfish from short-term 
environmental changes such as drought, provides ample sheltering and 
breeding habitat, and provides protection from stochastic events such 
as floods or golden algae blooms. Thus, the Bitter Lake NWR Middle 
Tract Wetlands population's current condition evaluation determined 
that occurrence, water quantity, water quality, and habitat diversity 
are in overall high current condition and the population has high 
resiliency.
    Unit 5: Bottomless Lakes State Park: Pecos pupfish have been 
routinely monitored at three sites in this AU and are found exclusively 
in sinkhole habitat. While Pecos pupfish were confirmed extirpated from 
Upper Figure 8 Lake during the 2021 monitoring, they remain extant 
throughout the remainder of the known occupied sites within the unit, 
including the adjacent Lower Figure 8 Lake sinkhole (Hatt 2021, p. 7).
    All of the Pecos pupfish sinkholes at Bottomless Lakes State Park 
are fed by springs from the San Andres artesian aquifer (Land 2003, p. 
229). Though some historical lowering of sinkhole levels has occurred, 
the recent trend is an increase in surface water levels in the 
sinkholes. Water levels in the sinkholes appear to be closely related 
to the overall fluctuation in water levels in the artesian aquifer 
(Land 2003, p. 231). No documented water contamination either from 
surface sources or natural water quality parameters has been recorded 
in the unit. Although sinkholes may exhibit more stable water quantity 
and quality, a mortality event was documented in 2020 in Upper Figure 8 
Lake, which illustrates the susceptibility of these habitats to 
stochastic events. The Bottomless Lakes State Park population's current 
condition evaluation determined that occurrence, water quantity, and 
water quality are in high condition, and habitat diversity is in 
moderate condition. Thus, the Bottomless Lakes State Park population is 
in overall high current condition and high resiliency.

[[Page 92757]]

    Unit 6: BLM Overflow Wetlands and Lea Lake: Pecos pupfish in this 
unit are surveyed in limited accessible areas of the BLM Overflow 
Wetlands (Hatt 2022, p. 2). Pecos pupfish are presumed extant 
throughout the suitable habitat within the wetland because installed 
fish barriers protect the unit from sheepshead minnow introgression 
(Hoagstrom et al. 2015, p. 16).
    Lea Lake typically exhibits stable water quantity throughout the 
year (Hoagstrom and Brooks 1999, p. 16). In addition, wetland water is 
supplied by several springs throughout the complex as well as surface 
flows during precipitation events. As a result of the different sources 
of water, the extent of aquatic habitat varies both seasonally and 
annually. However, owing to the constant source of water from Lea Lake, 
as well as the springs in the complex, permanent water remains in many 
locations. Additionally, there are no known water contamination issues 
in this unit.
    This unit contains a large wetland complex and the largest sinkhole 
in Bottomless Lakes State Park. This sinkhole was not included in Unit 
5 as it is not hydrologically connected to the other sinkholes in Unit 
5 and is hydrologically connected to the BLM Overflow Wetlands. The 
habitat diversity represented by these aquatic environments provides a 
buffer from stochastic events.
    The BLM Overflow Wetlands AU is the only other unit that has high 
internal redundancy. Similar to the Pecos River, the BLM Overflow 
Wetlands provide a large area with many microhabitats. This unit was 
historically connected to the Pecos River during high flows, but fish 
barriers installed to protect the unit from sheepshead minnow 
introgression have limited this connection. The BLM Overflow Wetlands 
and Lea Lake population's current condition evaluation determined that 
occurrence, water quantity, and habitat diversity are in high 
condition, and water quality is in moderate condition. Thus, the BLM 
Overflow Wetlands and Lea Lake population is in overall high current 
condition and has high resilience.
    Unit 7: Middle Pecos River: It is likely that Pecos pupfish are 
extirpated from the Pecos River between Brantley Dam and Red Bluff 
Reservoir. Sheepshead minnow are regularly caught between Brantley Dam 
and Red Bluff Reservoir, which indicates that they are present 
throughout this segment of the Pecos River system (Davenport 2023a, 
entire). Additionally, the middle Pecos River has regular issues with 
severe low flows and intermittency, water quality impairments, and 
stochastic events (Zymonas and Propst 2007, p. 45). The middle Pecos 
River population's current condition evaluation determined that water 
quantity and habitat diversity are in moderate condition, and water 
quality is in low condition. Due to the presence of sheepshead minnow, 
the middle Pecos River population is considered extirpated.
    Unit 8: Salt Creek (TX): Pecos pupfish in Salt Creek (TX) are 
currently present in only a single reach of the stream. While the fish 
at this location are not routinely monitored, a visit to this unit in 
2023 confirmed that fish are present (Montagne 2023, p. 2). Pecos 
pupfish from the lower reach of Salt Creek (TX), near the confluence 
with the Pecos River, were confirmed introgressed with sheepshead 
minnow from the Pecos River. An unidentified physical barrier in the 
lower reaches of Salt Creek (TX) appears to have limited the spread of 
sheepshead minnow and introgressed pupfish into the upper reaches that 
comprise this AU (Echelle et al. 2003b, pp. 4-6). The Salt Creek (TX) 
population's current condition evaluation determined that occurrence, 
water quantity, and habitat diversity are in moderate condition, and 
water quality is in low condition. Thus, the Salt Creek (TX) population 
is in overall moderate current condition and has moderate resilience.
    Unit 9: Lower Pecos River: Pecos pupfish have been extirpated from 
the lower Pecos River due to introgression with the sheepshead minnow. 
The flow of the lower Pecos River north of Independence Creek is 
subject to frequent and ongoing intermittency issues, regularly 
experiencing no flow events, especially during the irrigation season 
and during periods of drought. South of Independence Creek the 
character of the river changes to one with steeper bank and canyon and 
permanent water flow. The water in this unit has very high salinity and 
increasing ongoing impacts from contaminants (Hoagstrom 2009, pp. 35-
36). Hazardous material spills or leaks associated with oil and gas 
production are an ongoing problem in this unit and may be increasing in 
both number and frequency (Scanlon et al. 2020, p. 3511). The lower 
Pecos River population's current condition evaluation determined that 
water quantity and habitat diversity are in moderate condition, and 
water quality is in low condition. Due to the presence of sheepshead 
minnow, the lower Pecos River population is considered extirpated.
Redundancy
    Redundancy describes the ability of a species to withstand 
catastrophic events by maintaining multiple, resilient populations 
distributed (and connected, as appropriate) within the species' varied 
habitats and across the species' range. We assessed Pecos pupfish 
redundancy at two scales, within the individual AUs and across the 
range of the species. Within the analysis unit we looked at connection 
both internal to the unit and across adjacent units to characterize the 
overall redundancy of a unit. The overall redundancy of the unit could 
not be higher than the lowest internal or external redundancy score. 
Important to the discussion of redundancy in Pecos pupfish populations 
is the consideration of sheepshead minnow introgression. While 
connectivity enhances redundancy within and among AUs, this same 
connectivity increases the threat of sheepshead minnow introgression. A 
well-connected Pecos pupfish population is one that allows for 
dispersal and recolonization but is also one that is at increased risk 
of introgression. Redundancy throughout the species' range, coupled 
with healthy populations, may help lower the risk of introgression. A 
healthy, robust Pecos pupfish population may be more resistant to 
introgression and, thus, less likely to contribute to spread of hybrid 
fish (Kodric-Brown and Rosenfield 2004, p. 122).
    The Upper Pecos AU (Unit 1) is well connected throughout its length 
and the pattern of flow within the river likely creates a variety of 
microhabitat sites that are suitable for the Pecos pupfish. The Upper 
Pecos is moderately connected to adjacent off-channel units, though 
only at times of high flow.
    The Salt Creek Wilderness unit (Unit 2) is one of two units that 
are currently connected to the Pecos River during periods of high flow. 
In the Salt Creek Wilderness unit, the connection to the unit is 
limited to Salt Creek (NM) proper where the Pecos pupfish may be found 
in only one permanent pool in Salt Creek (NM). Within this unit, Pecos 
pupfish are distributed among several sinkholes and in Salt Creek (NM); 
there is no known, above-ground connection between these areas.
    Bitter Creek Drainage unit (Unit 3) does not have any known 
connection to adjacent AUs. Internally, many of the occupied sites 
within the Bitter Creek Drainage are isolated sinkholes. There is 
connection along Bitter Creek and to the springs that feed the creek; 
however, there is no known connection between the creek and adjacent 
sinkholes. It is

[[Page 92758]]

also surmised that there may be some underground connection between the 
springs in the Dragonfly Spring sinkhole area (Land and Huff 2009, p. 
20). It is currently unknown how extensive this connection is (if at 
all) or if a Pecos pupfish would be able to move between sinkholes 
underground.
    The Middle Tract unit (Unit 4) is connected to the Upper Pecos at 
the southern end of the unit during periods of high flow. While pupfish 
are likely widely distributed within the Middle Tract unit, connection 
among the different occupied sites is managed through a series of 
diversions and manmade impoundments. Water flow through the unit is 
generally north to south, and when the gates between the impoundments 
are open, flow is likely too great to allow Pecos pupfish to move up 
the current.
    The Bottomless Lakes State Park unit (Unit 5) does not have any 
known connection to adjacent AUs and is fully isolated from all other 
AUs.
    The BLM Overflow Wetlands unit (Unit 6) is the only other unit that 
has high internal redundancy. Similar to the Pecos River, the Overflow 
Wetlands provide a large area with many microhabitats. This unit was 
historically connected to the Pecos River during high flows, but fish 
barriers installed to protect the unit from sheepshead minnow 
introgression have limited this connection.
    Salt Creek (TX) unit (Unit 8) is directly connected to the lower 
Pecos River. There is a presumed natural barrier within Salt Creek (TX) 
upstream from the confluence that moderates this connectivity. The 
barrier has allowed non-introgressed Pecos pupfish to remain extant in 
the upper reaches of Salt Creek (TX) despite the presence of an 
introgressed population downstream. It is currently unknown how many 
extant sites are found in the upper areas of Salt Creek (TX), but the 
connection between them likely varies seasonally with the amount of 
water in the creek.
    We did not analyze the redundancy in the middle or lower Pecos 
River units (AUs 7 and 9), as the Pecos pupfish populations there are 
considered to be extirpated.
Representation
    Representation describes the ability of a species to adapt to 
changing environmental conditions over time and is characterized by the 
breadth of genetic and environmental diversity within and among 
populations. As previously discussed, Pecos pupfish are known from a 
variety of different aquatic environmental settings and show specific 
morphological variation related to these environmental settings. 
Populations have been documented in sinkholes, streams, marshes, 
managed wetlands, and rivers with varying physical characteristics 
(i.e., size, gradient, elevation, temperature, etc.).
    Although some limited genetic analysis has been done on the Pecos 
pupfish that indicated potential geographic structure to Pecos pupfish 
populations, research cautioned against a rigorous application of the 
results since the divergence was minor (Echelle and Echelle 2007, p. 
7). More recent research has shown differences between Pecos pupfish 
populations among the samples from Bitter Lake NWR, Bottomless Lakes 
State Park, and the BLM Overflow Wetlands (Whiteley 2023, entire), and 
morphological divergence in Pecos pupfish populations that corresponded 
to differing habitat use (Collyer et al. 2015, p. 187; Xu 2017, p. 22). 
While there are no studies that directly relates morphological 
differences in Pecos pupfish to genetic differentiation, the best 
available information suggests that including a range of aquatic 
environments (i.e., habitat diversity) represents much of the current 
diversity of the Pecos pupfish species (Echelle and Echelle 2007, p. 7; 
Collyer et al. 2015, p. 187; Xu 2017, p. 22; Whiteley 2023, entire). 
Therefore, we are using environmental setting as a surrogate for 
genetics to measure representation.
    Currently, the Pecos pupfish is found within nearly all of the 
historically occupied environmental settings but is considered 
extirpated from the Pecos River in southern New Mexico and northwestern 
Texas and is likely extirpated from several off-channel locations in 
that same region. However, the upper Pecos River, the only remaining 
riverine AU, has moderate resiliency, which reflects a potential 
increase in the loss of representation of riverine Pecos pupfish in New 
Mexico. The only remaining extant AU in Texas also has moderate 
resiliency, which presents a risk to representation of Pecos pupfish in 
Texas. Pecos pupfish have likely experienced some reduction in 
representation as a result of the large range reduction following 
extirpations from the Pecos River and off-channel locations in Texas 
and southern New Mexico.
Assessment of Current Viability
    The Pecos pupfish is currently distributed across seven of nine AUs 
covering the historical range. Within those seven AUs, four were 
assessed to be in high resiliency condition and three in moderate 
condition. Across the range of the species, we identified 66 distinct 
locations (sites) where Pecos pupfish have been recorded since 1992. As 
of 2023, 8 (12.1 percent) of these 66 sites are confirmed or presumed 
extirpated and four are in unknown status. The remaining 54 sites (81.2 
percent) are extant or presumed extant. Twenty-one sites (31.8 percent) 
have been confirmed as extant within the last 5 years. This does not 
consider losses that may have occurred before the first comprehensive 
range-wide surveys occurred in 1999 (Hoagstrom and Brooks 1999, 
entire). There has been a large decline in the extent of the occupied 
range because of the extirpation of Pecos pupfish from their historical 
range in the Pecos River below Brantley Dam (southern New Mexico and 
Texas). Pecos pupfish were historically found in riverine, stream, 
wetland, and sinkhole habitats and currently continue to be recorded in 
all of these habitats. Because of the reduction in the range caused by 
the extirpation of Pecos pupfish from a large section of the Pecos 
River, the species has experienced a reduction in both redundancy and 
representation. However, we do not have the data on the historical size 
of the Pecos pupfish population in the Pecos River or the genetic 
relationship between this population and others to adequately assess 
the relative importance of this population to the species. Regardless, 
the species has four populations in high condition, three in moderate 
condition, and none in low condition. These populations are well 
distributed throughout the range and among habitat types.
    Although there is uncertainty surrounding the demography of 
differing Pecos pupfish populations and their genetic relationships, 
data suggests that the Pecos pupfish still occurs in multiple 
populations representing the historical range of habitat variation for 
the species. Though declines in range extent and, likely, population 
size have occurred, 11 years of monitoring data suggest that the Pecos 
pupfish continues to have multiple, long-term persistent populations 
throughout its range.

Future Condition

    Using the same methods described for Current Condition, we assessed 
viability of the Pecos pupfish under three future scenarios at two 
timesteps, years 2050 and 2100, consistent with the best available 
information (Service 2024, pp. 76-102). Each scenario focused on a 
different climate projection for the Pecos River Basin, because 
changing climate conditions will affect the Pecos pupfish's required 
water quality and quantity parameters. We also assessed

[[Page 92759]]

the risk of sheepshead minnow introgression into other parts of the 
species' range.
    Although development such as urbanization, agriculture, and oil and 
gas extraction may have local effects on some Pecos pupfish sites, we 
do not expect substantial effects from these sources at the species or 
AU level. The exception to this situation is the potential for oil and 
gas development in the vicinity of Salt Creek (TX) to cause significant 
variation in stream flow. Oil and gas development in this area is 
expected to increase as energy demands are needed with increased human 
development (Llewellyn et al. 2021, pp. 81, 163, 171). While we do not 
have ongoing monitoring on Salt Creek (TX), stream gauges on the Black 
River in New Mexico have shown a direct correlation between oil and gas 
activities and reductions in stream flow, which provides relevant 
context for how Salt Creek (TX) may be impacted.
    Water availability in the Pecos River is influenced by a variety of 
factors including human development, primarily agriculture (see Loss 
and Decline of Surface and Groundwater above). However, this river is 
currently managed for multiple uses, including endangered species 
conservation, and future human water use from the river is not expected 
to substantially increase in the future. Given these factors, we find 
that the most important abiotic factors affecting Pecos pupfish 
viability will result from potential changes in water availability 
resulting from changing climatic conditions.
    The most important biotic factor is the potential for hybridization 
and genetic introgression by sheepshead minnow. If sheepshead minnow 
gain access to the upper Pecos River, the Salt Creek Wilderness and 
Middle Tract Wetlands AUs are most at risk of introgression because 
they are both connected hydrologically to the Pecos River during 
flooding events, thus allowing for potential movement of sheepshead 
minnow into these off-channel habitats. In the case of the Salt Creek 
Wilderness, only Salt Creek (NM) itself is vulnerable to sheepshead 
minnow invasion, as the isolated sink holes in that AU are not likely 
to be inundated during Pecos River flooding events. Because of the 
managed nature of the Middle Tract Wetlands by the Bitter Lake NWR 
staff and the existence of numerous water control structures that can 
reduce opportunities for fish movement, the vulnerability within the 
unit decreases with distance from the Pecos River. Managed water flows, 
manmade barriers, and direct human intervention would likely be 
employed to manage the spread of sheepshead minnow throughout the unit 
if the species were to gain access to the upper Pecos River. The lower 
portion of Salt Creek (TX) is already introgressed with sheepshead 
minnow, although some upstream portions of the stream have maintained 
non-introgressed pupfish. However, there is no clear barrier preventing 
additional upstream movement, so we assume the risk of introgression 
remains high there. The remaining three units adjacent to the Pecos 
River (Bitter Creek Drainage, Bottomless Lakes State Park, and the 
isolated sinkholes with the Salt Creek Wilderness) have either manmade 
or natural barriers that would prevent or minimize the chance of the 
spread of sheepshead minnow from the Pecos River into these units 
resulting in low introgression risk.
    The Intergovernmental Panel on Climate Change uses representative 
concentration pathways (RCPs) in climate change scenarios to project 
future concentrations of greenhouse gases (IPPC 2014, entire). Among 
the RCPs, the higher values mean higher greenhouse gas emissions and 
therefore higher global surface temperatures and more pronounced 
effects of climate change.
    To assess potential future conditions for the Pecos pupfish, we 
utilized results from a study that developed projections of future 
water management and hydrologic conditions to assess future water 
availability across the Pecos River Basin in New Mexico (Llewellyn et 
al. 2021, entire) and selected three scenarios to represent the 
variability of potential future conditions that could impact the Pecos 
pupfish and its habitat:
     Scenario 1: Hot and dry (RCP 8.5)--Steep increase in 
annual average temperature coupled with steep decreases in annual 
precipitation.
     Scenario 2: Hot and wet (RCP 8.5)--Steep increase in 
annual average temperature coupled with an increase in annual average 
precipitation.
     Scenario 3: Warm and dry (RCP 4.5)--Modest increase in 
annual average temperature and modest decrease in annual average 
precipitation.
    For each of the scenarios we assumed that the Pecos Pupfish 
Conservation Agreement will remain active, and the signatory agencies 
will continue monitoring the biological condition of the species and 
working to prevent spread of sheepshead minnow (Conservation Team 2022, 
p. 3).
Assumptions and Limitations
    As with any analysis, we made many assumptions that have 
consequences for our projections and interpretation of Pecos pupfish 
viability. First, we only used occurrence data starting in 1992 as the 
basis for our analysis. This was the first published range-wide survey 
of the Pecos pupfish and therefore provided the most comprehensive data 
set on Pecos pupfish occurrence. Sites that were only recorded prior to 
1992 were excluded from our analysis but were included in the overall 
picture of historical distribution.
    We were unable to locate information on thresholds or water body 
sizes that equate to an increase in extirpation risk specifically for 
Pecos pupfish. It is logical to assume populations that occupy smaller 
and shallower habitats are less resilient, but there are no clear 
thresholds in the literature at which the size raises extinction risk. 
We also did not find any specific thresholds for water quality impacts 
to Pecos pupfish populations that equate to a specific extirpation 
risk. Pupfish, including the Pecos pupfish, are known for their 
tolerance for water quality conditions that inhibit the fecundity and 
survival of other fish. We assumed that populations experiencing long-
term high temperatures or elevated salinity are less resilient, but 
there are no clear thresholds at which this long-term exposure raises 
extirpation risk. Thus, our categorization methodology may over- or 
under-estimate resiliency of populations depending on the actual 
biological thresholds.
    A critical assumption is that the primary stressors we identified, 
sheepshead minnow presence, and water quality and quantity alteration 
that leads to habitat loss and fragmentation, which are exacerbated due 
to climate change, are the primary threats to the species' long-term 
viability. Although land use practices and development have impacted 
the species historically, given the current distribution of Pecos 
pupfish populations, we anticipate that these activities would not have 
a large future impact.
    In order to characterize sheepshead minnow introgression into the 
future, we separately assessed this stressor. This stressor is a low 
probability, high consequence event where, if the event occurs, a 
population could be extirpated or highly degraded. The future scenarios 
included climate effects but assumed no change in sheepshead minnow 
presence. Both the climate change scenarios and the risk of sheepshead 
minnow introgression should be considered when assessing the status of 
the species.
    Another assumption in this SSA regards the role of conservation in 
future viability of the Pecos pupfish.

[[Page 92760]]

With the current conservation agreement in place, the Conservation Team 
has been proactive in supporting the species. We incorporated these 
efforts into several aspects of our analysis, such as our evaluation of 
the probability of current Pecos pupfish populations being invaded by 
nonnatives, taking into consideration conservation measures to prevent 
such invasion. However, we did not incorporate water conservation 
efforts into our future projects. While past water conservation, 
particularly in the PVACD, has had beneficial impacts to groundwater 
supply within the range of the Pecos pupfish, we were uncertain of the 
direct link between these measures and Pecos pupfish habitat. Based on 
this, we assume that water conservation efforts that maintain current 
aquifer levels, or limit future declines could improve resilience of 
Pecos pupfish populations. However, because both the implementation and 
success of any water conservation efforts and response of Pecos pupfish 
habitat to changing aquifer levels is unknown, were unable to 
incorporate this into our analysis. Surface Temperature
    Average annual surface temperatures as well as the incidence of 
extreme heat events are projected to increase across the entirety of 
the Southwest including the Pecos Basin (Vose et al. 2017, entire). 
Within the Pecos Basin, average surface temperatures could increase by 
as much as 13.32 [deg]F (-10.4 [deg]C) to an average surface 
temperature in excess of 70 [deg]F (21.1 [deg]C).
    As temperatures increase across the region, we anticipate a 
corresponding increase in evapotranspiration rates. Both temperature 
and evapotranspiration rates can have negative effects on Pecos pupfish 
and their habitat. Increasing temperatures increase the risk of golden 
algae blooms as well as increasing the chances that shallow habitat 
could exceed the thermal tolerance of Pecos pupfish. Greater 
evapotranspiration leads to lowering of water levels with the potential 
for corresponding increases in salinity and water temperatures and 
lowered dissolved oxygen. Lowered water levels also may lead to a 
reduction in the overall habitat available to Pecos pupfish along with 
the potential of the complete loss of water in shallow aquatic 
environments.
Precipitation and Aquifer Levels
    Precipitation changes related to climate change are more variable 
and less certain than those changes projected for temperature. In the 
Southwest, the occurrence of seasonal monsoons complicates the picture 
for overall projected changes to precipitation in the Pecos River 
Basin. Though generally models predict a drying trend across the Pecos 
Basin, under certain RCP 8.5 conditions, monsoon moisture increases, 
leading to an increase in average annual precipitation. Under both RCP 
4.5 and RCP 8.5 scenarios, snowpack in the headwater of the Pecos River 
decreases with a corresponding earlier snowmelt runoff (Llewellyn et 
al. 2021, p. 191). Though precipitation changes could potentially 
reduce flows into the San Andres aquifer from the Sacramento Mountains, 
the effect of lower snowpack and runoff will likely be most impactful 
to the Pecos River.
    The level of the San Andres aquifer likely directly impacts the 
water sources for most non-riverine Pecos pupfish habitats, except for 
those in Salt Creek (TX) (Land 2003, p. 228). Although we do not know 
the exact relationship between aquifer levels and the springs that 
provide flows to sinkholes, wetlands, and streams that provide Pecos 
pupfish habitat, we can infer that changes to the aquifer level will 
likely produce a corresponding change in spring flows. Levels in the 
San Andres aquifer are influenced by the amount of historical water in 
the aquifer and current inputs (Land and Huff 2009, p. 20) as well as 
pumping by users in the PVACD.
Future Scenarios
Scenario 1--Hot and Dry (RCP 8.5)
    In this scenario, future annual air temperature increases slightly, 
and annual precipitation decreases throughout the Pecos River Basin. 
Though temperatures increase in all seasons, summer and autumn 
temperatures are predicted to increase more than winter and spring 
temperatures. By 2100 (and likely much sooner), conditions in the Pecos 
River Basin would be much drier than the historical average. 
Precipitation would be greatly decreased in all seasons, though 
decreases would be most extreme during the monsoon season. Runoff 
inflow into the Pecos River Basin will decrease across every season, 
and the inflow that will occur is anticipated to be the result of very 
few large storm events (Llewellyn et al. 2021, p. 105).
Scenario 2--Hot and Wet (RCP 8.5)
    In this scenario, both temperature and annual precipitation 
increase throughout the Pecos River Basin. Increased temperatures 
retain more moisture in the atmosphere leading to increased monsoons. 
This scenario is more seasonally variable, with sharply increased 
inflow during the monsoon season and a steep decrease of inflow during 
the spring runoff. In this scenario, spring and summer temperatures 
increase more rapidly than fall and winter temperatures. While 
precipitation decreases during winter and spring, precipitation 
increases during the summer and autumn monsoon season, leading to an 
overall increase in precipitation within the Pecos River Basin. As a 
result of decreased winter precipitation, spring runoff is anticipated 
to decrease. However, a large increase in monsoon flows make up for the 
spring runoff decrease (Llewellyn et al. 2021, pp. 105-106).
Scenario 3--Warm and Dry (RCP 4.5)
    This scenario anticipates the smallest changes to temperature and 
precipitation of the three scenarios. By 2100, this scenario predicts 
slightly higher average temperatures and a slightly dryer climate. 
Importantly, summer and fall temperatures are anticipated to increase 
almost twice as much as winter and spring temperatures (Llewellyn et 
al. 2021, p. 101).
Future Condition Projections
    Using the projections for temperature, precipitation, and San 
Andres aquifer under the three scenarios outlined above, we then 
predicted the potential range of outcomes these scenarios could have on 
the Pecos pupfish. Future conditions were analyzed for each resiliency 
metric and summarized for each unit (Service 2024, appendix C, entire).
Scenario 1--Hot and Dry (RCP 8.5)
    This scenario forecasts extreme drying and higher temperatures 
across the Pecos River Basin. A decrease in precipitation across the 
basin along with increased air temperatures and overall drying trends 
is projected to lead to decreases in stream flow, spring output, and 
potentially a lowering of the aquifer that supports wetland and 
sinkhole habitats for the pupfish. Although the Pecos River is managed 
for flows that support endangered species such as the Pecos bluntnose 
shiner, decreasing precipitation will lead to an increase in drying 
days, impeding the ability of the upstream storage to deliver reliable 
water to both downstream users and retain adequate flow in the Pecos 
River and. Higher temperatures, particularly during the summer, will 
lead to an increase in water needs and increased groundwater pumping by 
agriculture in the PVACD. Higher temperatures also increase evaporative 
loss from water

[[Page 92761]]

bodies and could lead to decreases in habitats available for the 
pupfish.
    This scenario will have some negative effects on all Pecos pupfish 
AUs. The most severe impacts are anticipated to be to small streams. 
Salt Creek (TX), Salt Creek (NM), and Bitter Creek are all projected to 
dry and cease flowing during the hottest parts of the year leading to 
local fish kills, or in the case of Salt Creek (TX), possibly the loss 
of all habitats in the AU. All of these creeks currently experience 
intermittent drying events, and lower precipitation and increased 
temperatures in the future will exacerbate this existing condition that 
stresses these habitats. Wetland areas such as the BLM Overflow 
Wetlands and the managed wetlands on Bitter Lake NWR are also 
anticipated to be significantly impacted in this scenario. At the 2050 
timestep, given the climate projections, habitat conditions are 
projected to be similar to current conditions with minimal changes to 
most aquatic environments, with the exception of small streams that are 
already experiencing impacts from warming and drying temperatures. By 
2100, significant degradation to Pecos pupfish habitat and a decline in 
its distribution are expected. Shallow streams will likely no longer 
support permanent water leading to the loss of fish in Bitter Creek, 
Salt Creek (NM), and Salt Creek (TX), which would mean the extirpation 
of Pecos pupfish from Texas. Habitat extent in wetland habitats in the 
BLM Overflow Wetlands and Middle Tract on Bitter Lake NWR will be 
greatly reduced, and pupfish would be expected to persist only in 
deeper channels or near springs.
    Historically, the San Andres aquifer has been resilient and 
rebounded after extended drought (Land and Newton 2008, pp. 189-190). 
However, the conditions under this scenario, RCP 8.5, at 2100 will be 
much hotter and drier than the historical average and are expected to 
lead to unprecedented conditions in aquifer levels and surface water 
quality and quantity. Across the range of the Pecos pupfish, we 
anticipate substantial increases in salinity as a result of increased 
evapotranspiration. Although Pecos pupfish can tolerate higher salinity 
levels than most fish, significant salinity impairment (salinities 
greater than 35,000 mg/L) could lead to a reduction in suitable 
conditions for breeding. Increasing surface temperatures will lead to 
an increase in water temperatures and likely lowered dissolved oxygen 
saturation. This will be particularly pronounced in shallow habitat 
such as streams and wetlands. A substantial reduction in the aquifer 
level would reduce the outflow of springs leading to a loss of fish in 
habitats that rely on steady, perennial spring flow and a reduction (or 
elimination) of available habitat in shallower sinkholes. Additionally, 
the increasing temperature and evaporation could cause shallower 
habitats to exceed the thermal and saline tolerances of the Pecos 
pupfish. Consequently, we anticipate a reduction in both the number, 
extent, and population sizes of extant sites in sinkhole units. 
Finally, we anticipate greatly reduced flows in the Pecos River under 
this scenario. While reduced flows in the Pecos River have the 
potential to benefit the pupfish on a seasonal basis, long-term drying 
events will lead to the disconnection of occupied sites and increased 
impairment of water quality.
    Given these assumed future changes in the environment, by 2050, 
three AUs (Bitter Lake NWR Middle Tract Wetlands, Bottomless Lakes 
State Park, and BLM Overflow Wetlands and Lea Lake) are projected to 
remain in high condition, three units (Upper Pecos River, Salt Creek 
Wilderness, and Bitter Creek Drainage) are in moderate condition, and 
one unit (Salt Creek (TX)) is in low condition (Service 2024, p. 83). 
At 2100, only one AU (Bottomless Lakes State Park) is in high 
condition, four units (Upper Pecos River, Bitter Creek Drainage, Bitter 
Lake NWR Middle Tract Wetlands, and BLM Overflow Wetlands and Lea Lake) 
are in moderate condition, one unit (Salt Creek Wilderness) is in low 
condition, and one AU (Salt Creek (TX)) is extirpated. Although habitat 
conditions are expected to generally decline across the range, the 
Bottomless Lakes State Park AU is anticipated to remain in high 
condition because the sinkhole habitats there are expected to be less 
affected by potential aquifer declines. While only two units (Bitter 
Creek Drainage and Salt Creek (TX)) experience declines from current 
condition at 2050, by 2100 all units except Bottomless Lakes State Park 
experience declines from current condition.
Scenario 2--Hot and Wet (RCP 8.5)
    This scenario forecasts a significantly higher average annual 
surface temperature across the Pecos River Basin. Unlike Scenario 1, 
higher summer temperatures result in more moisture in the atmosphere, 
consequently leading to an increase in precipitation during the summer 
monsoon season (June-September). Overall higher surface temperatures 
will lead to similar outcomes as described under Scenario 1, such as 
water quality impairment, and reduction in habitat extent. However, the 
predicted increased monsoons may buffer some systems from the most 
severe impacts of increasing average temperatures.
    As with Scenario 1, the small streams are most likely to experience 
the most severe adverse impacts from increasing annual temperatures. 
These aquatic environments will likely experience more drying events 
and subsequent impairments to salinity, water temperatures, and 
dissolved oxygen. At the 2050 timestep, conditions appear similar to 
current conditions throughout much of the Pecos pupfish range. However, 
small streams will likely stop flowing during the hottest parts of the 
year, leading to local fish kills, or in the case of Salt Creek (TX), 
possibly the loss of all habitats in the AU. By 2100, rising annual 
temperatures may eliminate year-round stream flow in all but the 
wettest years. Consequently, we anticipate the loss of the Pecos 
pupfish population at Salt Creek (TX) and a reduction in occupied sites 
in Bitter Creek and the Salt Creek Wilderness. Increased temperatures 
will have an impact on shallower wetlands in the BLM Overflow Wetlands 
and Bitter Lake NWR Middle Tract Wetlands. Prolonged extreme air 
temperatures can adversely impact water quality and could result in 
decreased fitness, hinder breeding, or lead to fish kills. Sinkholes 
are the most stable environment for the Pecos pupfish, and this is 
unlikely to change in this scenario. The San Andres aquifer responds 
quickly to precipitation inputs, and an increase in monsoon season 
precipitation will likely prevent significant declines in sinkhole 
water levels.
    Given these assumed future changes in the environment, at 2050, 
three units (Bitter Lake NWR Middle Tract Wetlands, Bottomless Lakes 
State Park, and BLM Overflow Wetlands and Lea Lake) are projected to 
remain in high condition, three units (Upper Pacos River, Salt Creek 
Wilderness, and Bitter Creek Drainage) are in moderate condition, one 
unit (Salt Creek (TX)) is in low condition, and two units (Middle Pecos 
River and Lower Pecos River) remain extirpated. Under this scenario, 
only two units (Bitter Creek Drainage and Salt Creek (TX)) experience a 
decrease from current condition. At 2100, two units (Bottomless Lakes 
State Park and BLM Overflow Wetlands and Lea Lake) are in high 
condition, three units (Upper Pecos River, Bitter Creek Drainage, and 
Bitter Lake NWR Middle Tract Wetlands) are in moderate condition, one 
unit (Salt Creek Wilderness) is in low condition, and three units 
(Middle Pecos River, Salt Creek (TX), and Lower Pecos River) are

[[Page 92762]]

extirpated, with all units except Upper Pecos River, Bottomless Lakes 
State Park, and BLM Overflow Wetlands and Lea Lake experiencing a 
decrease from current condition.
Scenario 3--Warm and Dry (RCP 4.5)
    This scenario forecasts a minimal increase in yearly average 
temperatures and a minimal decrease in precipitation across the basin. 
Even minimal decreases in precipitation could have consequences for 
shallow streams in several units (Salt Creek Wilderness, Bitter Creek 
Drainage, and Salt Creek (TX)). Like the prior scenarios, the 2050 time 
step appears fairly similar to current condition. By 2100, small 
streams are likely experiencing increased water stress, and in dry 
years likely most of the stream environments will be dry. However, 
under this scenario, we anticipate minimal impacts to groundwater 
resources and thus minimal impacts to sinkhole, spring fed, and river 
habitats.
    At 2050, four units (Bitter Creek Drainage, Bitter Lake NWR Middle 
Tract Wetlands, Bottomless Lakes State Park, and BLM Overflow Wetlands 
and Lea Lake) are projected to be in high condition, and three units 
(Upper Pecos River, Salt Creek Wilderness, and Salt Creek (TX)) are in 
moderate condition, and two units (Middle Pecos River and Lower Pecos 
River) are extirpated. At 2100, three units (Bitter Lake NWR Middle 
Tract Wetlands, Bottomless Lakes State Park, and BLM Overflow Wetlands 
and Lea Lake) are projected to be in high condition, three units (Upper 
Pecos River, Salt Creek Wilderness, and Bitter Creek Drainage) are in 
moderate condition, one unit (Salt Creek (TX)) is in low condition, and 
two units (Middle Pecos River and Lower Pecos River) are extirpated. In 
Scenario 3, no units experience decreases from current condition at 
2050; however, at 2100 two units (Bitter Creek Drainage and Salt Creek 
(TX)) experience decreases from current condition.
Sheepshead Minnow
    Along with the three scenarios described above, we also considered 
the risk of sheepshead minnow introgression into the different AUs. 
Because sheepshead minnow are often used as bait fish, the most likely 
path for the sheepshead minnow to move into units existing with non-
introgressed Pecos pupfish populations is through a bait bucket 
transfer into the Pecos River upstream of Brantley Reservoir. Based on 
data collected from the lower Pecos River, this scenario would be 
highly likely to result in the introgression of the entire population 
of Pecos pupfish in the Pecos River (Unit 1, Upper Pecos River) 
(Whiteley 2023, p. 2). Bait bucket transfers are highly unlikely to 
occur in any of the other AUs, as these units are generally either well 
controlled or do not contain game fish species. As such, the most 
likely route for sheepshead minnow introgression into other AUs would 
be natural movement of sheepshead minnow from the Upper Pecos River AU, 
if they gained access there.
    The AUs most at risk of sheepshead minnow introgression from the 
upper Pecos River are the Salt Creek Wilderness and Middle Tract 
Wetlands, which are both connected hydrologically to the upper Pecos 
River during flooding events, allowing for potential movement of 
sheepshead minnow into these off-channel habitats. In the case of the 
Salt Creek Wilderness, only Salt Creek (NM) itself is vulnerable to 
sheepshead minnow invasion, as the isolated sink holes in that AU are 
not likely to be inundated during Pecos River flooding events. Because 
of the managed nature of the Middle Tract Wetlands by the Bitter Lake 
NWR staff and the existence of numerous water control structures that 
can reduce opportunities for fish movement, the vulnerability within 
the unit decreases with distance from the Pecos River. Managed water 
flows, manmade barriers, and direct human intervention would likely be 
employed to manage the spread of sheepshead minnow throughout the unit 
if the species were to gain access to the Upper Pecos River. The lower 
portion of Salt Creek (TX) is already introgressed with sheepshead 
minnow; however, despite the lack of a clear barrier preventing 
upstream movement, upstream portions of the stream have maintained non-
introgressed pupfish. Because we cannot identify a barrier, we assume 
the risk of introgression remains high. The remaining three units 
adjacent to the Pecos River (Salt Creek Wilderness, Bitter Creek 
Drainage, and Bottomless Lakes State Park) have either manmade or 
natural barriers that would prevent or minimize the chance of the 
spread of sheepshead minnow from the Pecos River into these units, 
resulting in low introgression risk.
Assessment of Future Viability
    We considered what the Pecos pupfish needs to maintain viability 
and characterized the status of the species in terms of its resiliency, 
redundancy, and representation. For the purpose of this assessment, we 
define viability as the ability of the species to sustain populations 
in natural ecosystems within a biologically meaningful timeframe: in 
this case, out to 2100. We chose 2100 because we have information to 
reasonably project the potential significant effects of stressors 
within the range of the Pecos pupfish within this timeframe. Based on 
the Pecos pupfish life history and habitat needs, and in consultation 
with the species' experts, we identified the potential stressors 
(negative influences), and the contributing sources of those stressors, 
that are likely to affect the species' future viability. We then 
evaluated how these potential future stressors would interact with 
current stressors, and how, and to what extent they would affect the 
species in the future. Based on the best available information, we 
believe the two largest influences on the future viability of the Pecos 
pupfish are the potential of introgression with sheepshead minnow and 
climate change-driven impacts to water quantity, water quality, and 
loss of habitat diversity. While water pollution and human development 
(particularly agricultural and oil and gas development) activities have 
likely influenced the species' current condition and may affect some 
areas (Salt Creek (TX)) in the future, we found that the changing 
climate and the related effects to water availability to sustain 
habitats has, and will continue to have, the greatest influence on the 
status of the Pecos pupfish. Sheepshead minnow introduction, while much 
less predictable, does have the potential to impact Pecos pupfish 
populations above Brantley Dam should an introduction occur.
    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have 
analyzed the cumulative effects of identified threats and conservation 
actions on the species. To assess the current and future condition of 
the species, we evaluate the effects of all the relevant factors that 
may be influencing the species, including threats and conservation 
efforts. Because the SSA framework considers not just the presence of 
the factors, but to what degree they collectively influence risk to the 
entire species, our assessment integrates the cumulative effects of the 
factors and replaces a standalone cumulative-effects analysis.

Determination of Pecos Pupfish 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 in

[[Page 92763]]

danger of extinction throughout all or a significant portion of its 
range, and a ``threatened species'' as a species likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range. The Act requires that we determine 
whether a species meets the definition of an endangered species or a 
threatened species because of any of the following factors: (A) The 
present or threatened destruction, modification, or curtailment of its 
habitat or range; (B) overutilization for commercial, recreational, 
scientific, or educational purposes; (C) disease or predation; (D) the 
inadequacy of existing regulatory mechanisms; or (E) other natural or 
manmade factors affecting its continued existence.

Status Throughout All of Its Range

    Our assessment of best available information indicates that 
currently two of the nine known Pecos pupfish populations have been 
extirpated, and three others are in moderate condition. The majority of 
known occupied Pecos pupfish sites are within the other five units 
around Bitter Lake NWR and Bottomless Lakes State Park in New Mexico 
(AUs 2-6). Within these units, four were found to be in high condition 
and one in moderate condition, indicating that multiple areas across 
the species' core range have high resiliency. The small Salt Creek AU 
in Texas is currently in moderate condition. This unit is disconnected 
from the remainder of the species' range in New Mexico, providing some 
redundancy in maintaining a relatively large geographic range. The two 
large units of the Lower and Middle Pecos River have been previously 
extirpated due to the introgression of the sheepshead minnow. Loss of 
these parts of the range represent a significant reduction in the 
overall range and redundancy for the species and loss of a large 
segment of the riverine habitats historically available to the species. 
The riverine habitats continue to be represented by the Upper Pecos 
River Unit.
    Under all three plausible future scenarios, species condition would 
be reduced by 2100. In the hottest and driest scenario (Scenario 1), 
shallow streams are likely to be lost, leading to the extirpation of 
Pecos pupfish in Salt Creek (TX) and a reduction in redundancy and 
representation in the Salt Creek Wilderness and Bitter Creek Drainage 
units. Deeper sinkholes and wetlands are more stable and are expected 
to maintain suitable conditions for the Pecos pupfish under all 
scenarios. However, units such as Bitter Creek Drainage, Middle Tract, 
and BLM Overflow Wetlands are more vulnerable to losses in redundancy 
in Scenario 1 due to susceptibility to habitat losses from future 
drying climatic conditions. The Pecos River may also be unable to 
sustain year-round flows under conditions predicted in Scenario 1. The 
increased stream flows from projected increase in monsoons in Scenario 
2 help maintain sinkhole habitats throughout the range of the Pecos 
pupfish, and to a lesser extent, likely may buffer wetland habitats 
from the most severe impacts of increased temperatures. However, small 
streams are likely still at elevated risk of being lost or experiencing 
long-term drying or mortality events. Finally, in the mildest future 
climate scenario (Scenario 3), further effects to most habitat 
(wetlands, sinkholes, and riverine) are anticipated to be minimal. 
However, like the other two scenarios, shallow streams likely will 
experience drying and mortality events.
    Under all three scenarios, we anticipate some reductions to 
resilience, redundance, and representation. Although some additional 
changes to Pecos pupfish status are projected to occur by 2050, we 
anticipate that measurable changes to viability will be more apparent 
by 2100. The resilience of the aquifer to small year-to-year variation 
and the adaptability of the Pecos pupfish to variable habitat 
conditions will likely offset some of the climate changes through 2050. 
Under all scenarios, at least one AU remains in high condition. Under 
both Scenarios 1 and 2, Pecos pupfish are projected to be extirpated 
from Salt Creek (TX), eliminating the only population outside of New 
Mexico that has been described as genetically different from the core 
populations in New Mexico. Pecos pupfish experience most losses of 
known occupied sites under Scenario 1, though losses would be likely to 
occur under scenarios 2 and 3 as well. Bottomless Lakes State Park 
remains the only AU that would be in high condition under all three 
scenarios.
    Concurrent with the effects of climate change is the risk of 
expansion of sheepshead minnow and subsequent hybridization with Pecos 
pupfish. Salt Creek (TX) is already at high risk of loss due to 
sheepshead minnow introgression. The Upper Pecos River is currently 
highly vulnerable to sheepshead minnow introduction via a bait bucket 
transfer. Should this introduction occur, non-introgressed Pecos 
pupfish would likely be extirpated from this unit, and, as a 
consequence there would be no remaining Pecos pupfish in the Pecos 
River. This would also increase the potential for sheepshead minnow 
invasion into portions of the Salt Creek Wilderness, the Middle Tract 
Wetlands, and possibly the Overflow Wetlands units.
    The Pecos Pupfish Conservation Agreement will continue to provide 
guidance for agencies and partners working toward Pecos pupfish 
conservation through several means. First, the monitoring outlined in 
the conservation agreement will provide a long-term data set on the 
persistence of Pecos pupfish and, as methods are refined, population 
trends within four AUs (Bitter Creek Drainage and Bitter Lake NWR 
Middle Tract Wetlands, BLM Overflow Wetlands and Lea Lake, and 
Bottomless Lakes State Park). This monitoring will allow partners to 
detect potential sheepshead minnow introgression and allow for the 
detection of long-term declines or extirpations of Pecos pupfish. 
Secondly, the conservation agreement will help provide for ongoing 
maintenance (or potentially additional) barriers to fish passage that 
may protect some of the AUs from sheepshead minnow introgression should 
a bait bucket transfer into the Upper Pecos River occur. Finally, the 
agreement can reduce the opportunity for further invasions by a 
collaborative effort of State and Federal entities to enforce existing 
baitfish regulations.
    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we find that Pecos pupfish populations will continue to face 
the ongoing risk of sheepshead minnow introgression, and populations 
will remain small and isolated from one another. The risk of sheepshead 
minnow introgression is cumulative, meaning that the risk builds over 
time such that the risk of this species being introduced into the 
current Pecos pupfish range by a bait bucket transfer is higher in the 
future than it is currently. Additionally, Pecos pupfish populations 
will experience reductions in resiliency, redundance, and 
representation through 2050, with more measurable declines by 2100 due 
to decreased surface water availability, increased frequency of 
drought, higher than average temperatures, and continued groundwater 
depletion.
    We considered whether the Pecos pupfish is presently in danger of 
extinction and determined that endangered status is not appropriate. 
The current conditions assessed in the SSA report show that the Pecos 
pupfish is distributed across seven of nine AUs across the historical 
range. Although there may have been reductions from

[[Page 92764]]

the historical range and population sizes, monitoring data indicate 
that the Pecos pupfish continues to have multiple, long-term, 
persistent populations throughout the range. Currently only two of the 
seven AUs are at high risk for sheepshead minnow introgression, and 
four AUs are not subjected to declines in water quantity. While threats 
are currently acting on the species and many of those threats are 
expected to continue into the future, we did not find that the species 
is currently in danger of extinction throughout all of its range. We 
believe the demand on water in the Pecos River Basin is expected to 
increase based on climate change projections (Sites Southwest 2008, pp. 
6-3, 6-6), but adequate aquifer levels may be maintained until 2100 
(Llewellyn et al. 2021, p. 100). Thus, after assessing the best 
available information, we conclude that the Pecos pupfish is not 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, 435 
F. Supp. 3d 69 (D.D.C. 2020) (Everson), vacated the provision 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'' (hereafter ``Final Policy''; 79 FR 
37578, July 1, 2014) that provided if the Services determine that a 
species is threatened throughout all of its range, the Services will 
not analyze whether the species is endangered in a significant portion 
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 Everson, we now consider whether 
the species is in danger of extinction in a significant portion of its 
range. In undertaking this analysis for Pecos pupfish, we choose to 
address the status question first.
    We evaluated the range of the Pecos pupfish to determine if the 
species is in danger of extinction in any portion of its range. The 
range of a species can theoretically be divided into portions in an 
infinite number of ways. We focused our analysis on portions of the 
species' range that may meet the definition of an endangered species. 
For Pecos pupfish, we considered whether the threats or their effects 
on the species are greater in any biologically meaningful portion of 
the species' range than in other portions such that the species is in 
danger of extinction in that portion.
    We examined the range for biologically meaningful portions based on 
the four broad categories of aquatic environments that Pecos pupfish 
occupy throughout its range, which reflect phylogenic relationships as 
well as physiogeographical differences in aquatic habitat. The aquatic 
environments germane to the range of the Pecos pupfish are riverine 
(includes the upper, middle, and lower Pecos River segments), shallow 
stream (includes Salt Creek (NM) and Salt Creek (TX)), sinkholes 
(includes Salt Creek Wilderness, Bitter Creek Drainage, and Bottomless 
Lakes State Park), and wetlands (includes Bitter Creek Middle Tract 
Wetlands and BLM Overflow Wetlands and Lea Lake).
    Once we identified the biologically meaningful portions to examine, 
we then turned to the question of whether these portions may have a 
different biological status. Of these aquatic environments, the 
riverine environment contains just one population, the upper Pecos 
River, which is in moderate condition. The other environments have 
multiple populations, including four in high condition. Therefore, we 
are examining the riverine environment to determine if it has a 
different status than the remainder of the range.
    We evaluated the available information about this portion of the 
range of Pecos pupfish that occupies the upper Pecos River in this 
context, assessing its biological significance in terms of condition 
criteria (genetic security, occurrence, water quality, water quantity, 
and habitat diversity; see Current Condition) used to assign the 
current condition of Pecos pupfish populations. While the entire Pecos 
River is characterized as a sometimes fairly shallow and meandering 
riverine habitat with ephemeral tributaries, the primary risk to the 
upper Pecos River population is the introduction of sheepshead minnow. 
The single population in this aquatic habitat is also affected by 
severe low flow or no flow events and intermittency, as well as water 
quality impairments. Sheepshead minnow were introduced to portions of 
the Pecos River in the 1980s; Brantley Dam currently serves as a 
barrier to prevent sheepshead minnow from naturally moving north into 
the upper Pecos River. Because sheepshead minnow are often used as bait 
fish, the most likely path for the sheepshead minnow to move into non-
introgressed Pecos pupfish populations is through a bait bucket 
transfer into the Pecos River upstream of Brantley Reservoir. At that 
point, sheepshead minnow could naturally spread from the upper Pecos 
River to additional Pecos pupfish populations. Because the risk of 
introduction of sheepshead minnow is equal across all habitat types and 
is the primary reason that we found the Pecos pupfish to be threatened 
rangewide, there is not a difference in risk that would cause the upper 
Pecos River to have a different status than the remainder of the range.
    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 does not conflict with the courts' 
holdings in Desert Survivors v. U.S. Department of the Interior, 321 F. 
Supp. 3d 1011, 1070-74 (N.D. Cal. 2018) and Center for Biological 
Diversity v. Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, 
in reaching this conclusion, we did not apply the aspects of the Final 
Policy, including the definition of ``significant'' that those court 
decisions held to be invalid.

Determination of Status

    Based on of the best scientific and commercial data available, we 
determine that the Pecos pupfish meets the Act's definition of a 
threatened species. Therefore, we propose to list the Pecos pupfish as 
a threatened species in accordance with sections 3(20) and 4(a)(1) of 
the Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition as a listed 
species, planning and implementation of recovery actions, requirements 
for Federal protection, and prohibitions against certain practices. 
Recognition through listing results in public

[[Page 92765]]

awareness, and conservation by Federal, State, Tribal, and local 
agencies, foreign governments, private organizations, and individuals. 
The Act encourages cooperation with the States and other countries and 
calls for recovery actions to be carried out for listed species. The 
protection required by Federal agencies, including the Service, and the 
prohibitions against certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Section 4(f) of the Act calls for the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The goal of this process is to restore listed 
species to a point where they are secure, self-sustaining, and 
functioning components of their ecosystems.
    The recovery planning process begins with development of a recovery 
outline made available to the public soon after a final listing 
determination. The recovery outline guides the immediate implementation 
of urgent recovery actions while a recovery plan is being developed. 
Recovery teams (composed of species experts, Federal and State 
agencies, nongovernmental organizations, and stakeholders) may be 
established to develop and implement recovery plans. The recovery 
planning process involves the identification of actions that are 
necessary to halt and reverse the species' decline by addressing the 
threats to its survival and recovery. The recovery plan identifies 
recovery criteria for review of when a species may be ready for 
reclassification from endangered to threatened (``downlisting'') or 
removal from protected status (``delisting''), and methods for 
monitoring recovery progress. Recovery plans also establish a framework 
for agencies to coordinate their recovery efforts and provide estimates 
of the cost of implementing recovery tasks. Revisions of the plan may 
be done to address continuing or new threats to the species, as new 
substantive information becomes available. The recovery outline, draft 
recovery plan, final recovery plan, and any revisions will be available 
on our website as they are completed (https://www.fws.gov/program/endangered-species), or from our New Mexico Ecological Services Field 
Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    If this species is listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost-share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. In addition, 
pursuant to section 6 of the Act, the State(s) of New Mexico and Texas 
would be eligible for Federal funds to implement management actions 
that promote the protection or recovery of the Pecos pupfish. 
Information on our grant programs that are available to aid species 
recovery can be found at: https://www.fws.gov/service/financial-assistance.
    Although the Pecos pupfish is only proposed for listing under the 
Act at this time, please let us know if you are interested in 
participating in recovery efforts for this species. Additionally, we 
invite you to submit any new information on this species whenever it 
becomes available and any information you may have for recovery 
planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7 of the Act is titled Interagency Cooperation and mandates 
all Federal action agencies to use their existing authorities to 
further the conservation purposes of the Act and to ensure that their 
actions are not likely to jeopardize the continued existence of listed 
species or adversely modify critical habitat. Regulations implementing 
section 7 are codified at 50 CFR part 402.
    Section 7(a)(2) states that each Federal action agency shall, in 
consultation with the Secretary, ensure that any action they authorize, 
fund, or carry out is not likely to jeopardize the continued existence 
of a listed species or result in the destruction or adverse 
modification of designated critical habitat. Each Federal agency shall 
review its action at the earliest possible time to determine whether it 
may affect listed species or critical habitat. If a determination is 
made that the action may affect listed species or critical habitat, 
formal consultation is required (50 CFR 402.14(a)), unless the Service 
concurs in writing that the action is not likely to adversely affect 
listed species or critical habitat. At the end of a formal 
consultation, the Service issues a biological opinion, containing its 
determination of whether the federal action is likely to result in 
jeopardy or adverse modification.
    In contrast, section 7(a)(4) of the Act requires Federal agencies 
to confer with the Service on any action which is likely to jeopardize 
the continued existence of any species proposed to be listed under the 
Act or result in the destruction or adverse modification of critical 
habitat proposed to be designated for such species. Although the 
conference procedures are required only when an action is likely to 
result in jeopardy or adverse modification, action agencies may 
voluntarily confer with the Service on actions that may affect species 
proposed for listing or critical habitat proposed to be designated. In 
the event that the subject species is listed or the relevant critical 
habitat is designated, a conference opinion may be adopted as a 
biological opinion and serve as compliance with section 7(a)(2).
    Examples of discretionary actions for the Pecos pupfish that may be 
subject to conference and consultation procedures under section 7 are 
management of Federal lands administered by the BLM, the BOR, the 
Corps, and the Service's NWR System as well as actions that require a 
Federal permit (such as a permit from the Corps under section 404 of 
the Clean Water Act (33 U.S.C. 1251 et seq.) or actions funded be 
Federal agencies such as the Federal Highway Administration, Federal 
Aviation Administration, or the Federal Emergency Management Agency. 
Federal actions not affecting listed species or critical habitat--and 
actions on State, Tribal, local, or private lands that are not 
federally funded, authorized, or carried out by a Federal agency--do 
not require section 7 consultation. Federal agencies should coordinate 
with the New Mexico Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT) with any specific questions on section 7 
consultation and conference requirements.

II. Protective Regulations Under Section 4(d) of the Act

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the Secretary shall issue such regulations as she deems 
necessary and advisable to provide for the

[[Page 92766]]

conservation of species listed as threatened species. 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. With these two sentences in section 4(d), Congress 
delegated broad authority to the Secretary to determine what 
protections would be necessary and advisable to provide for the 
conservation of threatened species, and even broader authority to put 
in place any of the section 9 prohibitions, for a given species.
    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, as a valid 
exercise of agency authority, rules developed under section 4(d) that 
included limited prohibitions against takings (see Alsea Valley 
Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington 
Environmental Council v. National Marine Fisheries Service, 2002 WL 
511479 (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 [her] with regard to the permitted activities for those 
species. [She] may, for example, permit taking, but not importation of 
such species, or [she] 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).
    The provisions of this species' proposed protective regulations 
under section 4(d) of the Act are one of many tools that we would use 
to promote the conservation of the Pecos pupfish. The proposed 
protective regulations would apply only if and when we make final the 
listing of the Pecos pupfish as a threatened species. Nothing in 4(d) 
rules 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 Pecos pupfish. As mentioned previously 
in Available Conservation Measures, section 7(a)(2) of the Act requires 
Federal agencies, including the Service, to ensure that any action they 
authorize, fund, or carry out is not likely to jeopardize the continued 
existence of any endangered species or threatened species or result in 
the destruction or adverse modification of designated critical habitat 
of such species. In addition, even before the listing of any species or 
the designation of its critical habitat is finalized, section 7(a)(4) 
of the Act requires Federal agencies to confer with the Service on any 
agency action which is likely to jeopardize the continued existence of 
any species proposed to be listed under the Act or result in the 
destruction or adverse modification of critical habitat proposed to be 
designated for such species. These requirements are the same for a 
threatened species regardless of what is included in its 4(d) rule.
    Section 7 consultation is required for Federal actions that ``may 
affect'' a listed species regardless of whether take caused by the 
activity is prohibited or excepted by a 4(d) rule (under application of 
a ``blanket rule'' (for more information, see 89 FR 23919, April 5, 
2024) or a species-specific 4(d) rule). A 4(d) rule does not change the 
process and criteria for informal or formal consultations and does not 
alter the analytical process used for biological opinions or 
concurrence letters. For example, as with an endangered species, if a 
Federal agency determines that an action is ``not likely to adversely 
affect'' a threatened species, this will require the Service's written 
concurrence (50 CFR 402.13(c)). Similarly, if a Federal agency 
determines that an action is ``likely to adversely affect'' a 
threatened species, the action will require formal consultation with 
the Service and the formulation of a biological opinion (50 CFR 
402.14(a)). Because consultation obligations and processes are 
unaffected by 4(d) rules, we may consider developing tools to 
streamline future intra-Service and inter-agency consultations for 
actions that result in forms of take that are not prohibited by the 
4(d) rule (but that still require consultation). These tools may 
include consultation guidance, online consultation processes via the 
Service's digital project planning tool (Information for Planning and 
Consultation; https://ipac.ecosphere.fws.gov/), template language for 
biological opinions, or programmatic consultations.
    Exercising the Secretary's authority under section 4(d) of the Act, 
we propose to apply the protections for the Pecos pupfish through our 
regulations at 50 CFR 17.31(a). In our April 5, 2024, final rule 
revising those regulations (89 FR 23919 at 23922-23923), we found that 
applying those regulations 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 threatened species. We 
have not identified any ways in which a protective regulation for this 
threatened species would need to differ from the regulations at 50 CFR 
17.31(a) in order to contain the protections that are necessary and 
advisable to provide for the conservation of the Pecos pupfish. 
Therefore, if we finalize this rule as proposed, the regulations at 50 
CFR 17.31(a) apply. This means that except as provided in 50 CFR 17.4 
through 17.8, or in a permit issued pursuant to 50 CFR 17.32, all of 
the provisions of 50 CFR 17.21 for endangered wildlife, except Sec.  
17.21(c)(3) and (5), would apply to the Pecos pupfish, and the 
provisions of 50 CFR 17.32(b) concerning exceptions for certain 
entities would also apply to the species.

Provisions of the Proposed 4(d) Rule

    Exercising the Secretary's authority under section 4(d) of the Act, 
we have developed a proposed rule that is designed to address the Pecos 
pupfish's conservation needs. As discussed previously in Summary of 
Biological Status and Threats, we have concluded that the Pecos pupfish 
is likely to become in danger of extinction within the foreseeable 
future primarily due to risk of introduction of nonnative invasive 
sheepshead minnow into new locations occupied by Pecos pupfish, loss 
and declines of surface and ground water, degradation of water quality, 
and habitat loss and fragmentation. Section 4(d) requires the Secretary 
to issue such regulations as she deems necessary and advisable to 
provide for the conservation of each threatened species and authorizes 
the Secretary to include among those protective regulations any of the 
prohibitions that section 9(a)(1) of the Act prescribes for endangered 
species. We are not required to make a ``necessary and advisable'' 
determination when we apply or do not apply specific section 9 
prohibitions to a threatened species (In re: Polar Bear Endangered 
Species Act Listing and 4(d) Rule Litigation, 818 F. Supp. 2d 214, 228 
(D.D.C. 2011) (citing Sweet Home Chapter of Communities for a Great 
Oregon v. Babbitt, 1 F.3d 1, 8 (D.C. Cir. 1993), rev'd on other 
grounds, 515 U.S. 687 (1995))). Nevertheless, even though

[[Page 92767]]

we are not required to make such a determination, we have chosen to be 
as transparent as possible and explain below why we find that, if 
finalized, the protections, prohibitions, and exceptions in this 
proposed rule as a whole satisfy the requirement in section 4(d) of the 
Act to issue regulations deemed necessary and advisable to provide for 
the conservation of the Pecos pupfish.
    The protective regulations we are proposing for Pecos pupfish 
incorporate prohibitions from section 9(a)(1) to address the threats to 
the species. The prohibitions of section 9(a)(1) of the Act, and 
implementing regulations codified at 50 CFR 17.21, make it illegal for 
any person subject to the jurisdiction of the United States to commit, 
to attempt to commit, to solicit another to commit or to cause to be 
committed any of the following acts with regard to any endangered 
wildlife: (1) import into, or export from, the United States; (2) take 
(which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect) within the United States, within the territorial 
sea of the United States, or on the high seas; (3) possess, sell, 
deliver, carry, transport, or ship, by any means whatsoever, any such 
wildlife that has been taken illegally; (4) deliver, receive, carry, 
transport, or ship in interstate or foreign commerce, by any means 
whatsoever and in the course of commercial activity; or (5) sell or 
offer for sale in interstate or foreign commerce. This protective 
regulation includes all of these prohibitions because the Pecos pupfish 
is at risk of extinction in the foreseeable future and putting these 
prohibitions in place will help to prevent further declines, preserve 
the species' remaining populations, slow its rate of decline, and 
decrease synergistic, negative effects from other ongoing or future 
threats.
    In particular, this proposed 4(d) rule would provide for the 
conservation of the Pecos pupfish by prohibiting the following 
activities, unless they fall within specific exceptions or are 
otherwise authorized or permitted: importing or exporting; take; 
possession and other acts with unlawfully taken specimens; delivering, 
receiving, carrying, 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.
    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. Regulating 
take would help preserve the species' remaining populations, slow their 
rate of decline, and decrease cumulative effects from other ongoing or 
future threats. Therefore, we propose to prohibit take of the Pecos 
pupfish, except for take resulting from those actions and activities 
specifically excepted by the 4(d) rule.
    Exceptions to the prohibition on take would include all of the 
general exceptions to the prohibition on take of endangered wildlife, 
as set forth in 50 CFR 17.21.
    Despite these prohibitions regarding threatened species, we may 
under certain circumstances issue permits to carry out one or more 
otherwise-prohibited activities, including those described above. The 
regulations that govern permits for threatened wildlife state that the 
Director may issue a permit authorizing any activity otherwise 
prohibited with regard to threatened species. These include permits 
issued for the following purposes: for 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 (50 CFR 
17.32). The statute also contains certain exemptions from the 
prohibitions, which are found in sections 9 and 10 of the Act.
    In addition, to further the conservation of the species, any 
employee or agent of the Service, any other Federal land management 
agency, the National Marine Fisheries Service, a State conservation 
agency, or a federally recognized Tribe, who is designated by their 
agency or Tribe for such purposes, may, when acting in the course of 
their official duties, take threatened wildlife without a permit if 
such action is necessary to: (i) Aid a sick, injured, or orphaned 
specimen; or (ii) dispose of a dead specimen; or (iii) salvage a dead 
specimen that may be useful for scientific study; or (iv) remove 
specimens that constitute a demonstrable but nonimmediate threat to 
human safety, provided that the taking is done in a humane manner; the 
taking may involve killing or injuring only if it has not been 
reasonably possible to eliminate such threat by live-capturing and 
releasing the specimen unharmed, in an appropriate area.
    We recognize the special and unique relationship that we have 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 must 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, would be able to conduct 
activities designed to conserve Pecos pupfish that may result in 
otherwise prohibited take without additional authorization.
    The proposed 4(d) rule would also provide for the conservation of 
the species by allowing exceptions that incentivize conservation 
actions or that, while they may have some minimal impact on the Pecos 
pupfish, are not expected to rise to the level that would have a 
negative impact (i.e., would have only de minimis impacts) on the 
species' conservation. The exceptions to these prohibitions include 
incidental and intentional take (described below) that are expected to 
have negligible impacts to the Pecos pupfish and its habitat.
    Those exceptions include the following activities:
    (1) Management and maintenance of ponds that are stocked with 
captive-bred Pecos pupfish by the State of Texas.
    (2) Research activities on individual Pecos pupfish in those ponds 
by holders of a valid State-issued scientific research permit, 
zoological permit, or educational display permit. Individuals 
exercising this exception must provide to the State of Texas annual 
reports containing the following information: the nature of research 
performed; dates of fieldwork; the number of individuals collected or 
captured, and the methods used to obtain them; a description of any 
accidental injuries or mortalities; the number of individuals from 
which genetic material was collected, the type of tissue collected, and 
the institution or location where the genetic material is being stored. 
The location of fieldwork and landowner identifying information is not 
required. This exception applies only to individuals with a current, 
valid permit from the State of Texas and applies only to research 
conducted on pupfish ponds on private lands that are

[[Page 92768]]

part of the TPWD Pecos pupfish production pond effort. The State of 
Texas must provide annual reports to the Service regarding use of this 
exception.

III. Critical Habitat

Background

    Section 4(a)(3) of the Act requires that, to the maximum extent 
prudent and determinable, we designate a species' critical habitat 
concurrently with listing the species. Critical habitat is defined in 
section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Our regulations at 50 CFR 424.02 define the geographical area 
occupied by the species as an area that may generally be delineated 
around species' occurrences, as determined by the Secretary (i.e., 
range). Such areas may include those areas used throughout all or part 
of the species' life cycle, even if not used on a regular basis (e.g., 
migratory corridors, seasonal habitats, and habitats used periodically, 
but not solely by vagrant individuals).
    Conservation, as defined under section 3 of the Act, means to use 
and the use of all methods and procedures that are necessary to bring 
an endangered or threatened species to the point at which the measures 
provided pursuant to the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping, and transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot be otherwise 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that each Federal action agency ensure, in 
consultation with the Service, that any action they authorize, fund, or 
carry out is not likely to result in the destruction or adverse 
modification of designated critical habitat. The designation of 
critical habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area. Such 
designation also does not allow the government or public to access 
private lands. Such designation does not require implementation of 
restoration, recovery, or enhancement measures by non-Federal 
landowners. Rather, designation requires that, where a landowner 
requests Federal agency funding or authorization for an action that may 
affect an area designated as critical habitat, the Federal agency 
consult with the Service under section 7(a)(2) of the Act. If the 
action may affect the listed species itself (such as for occupied 
critical habitat), the Federal agency would have already been required 
to consult with the Service even absent the designation because of the 
requirement to ensure that the action is not likely to jeopardize the 
continued existence of the species. Even if the Service were to 
conclude after consultation that the proposed activity is likely to 
result in destruction or adverse modification of the critical habitat, 
the Federal action agency and the landowner are not required to abandon 
the proposed activity, or to restore or recover the species; instead, 
they must implement ``reasonable and prudent alternatives'' to avoid 
destruction or adverse modification of critical habitat.
    Under the first prong of the Act's definition of critical habitat, 
areas within the geographical area occupied by the species at the time 
it was listed are included in a critical habitat designation if they 
contain physical or biological features (1) which are essential to the 
conservation of the species and (2) which may require special 
management considerations or protection. For these areas, critical 
habitat designations identify, to the extent known using the best 
scientific data available, those physical or biological features that 
are essential to the conservation of the species (such as space, food, 
cover, and protected habitat).
    Under the second prong of the Act's definition of critical habitat, 
we can designate critical habitat in areas outside the geographical 
area occupied by the species at the time it is listed, upon a 
determination that such areas are essential for the conservation of the 
species.
    Section 4(b)(2) of the Act requires that we designate critical 
habitat on the basis of the best scientific data available. Further, 
our Policy on Information Standards Under the Endangered Species Act 
(published in the Federal Register on July 1, 1994 (59 FR 34271)), the 
Information Quality Act (section 515 of the Treasury and General 
Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; 
H.R. 5658)), and our associated Information Quality Guidelines provide 
criteria, establish procedures, and provide guidance to ensure that our 
decisions are based on the best scientific data available. They require 
our biologists, to the extent consistent with the Act and with the use 
of the best scientific data available, to use primary and original 
sources of information as the basis for recommendations to designate 
critical habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information compiled in the SSA report and information developed during 
the listing process for the species. Additional information sources may 
include any generalized conservation strategy, criteria, or outline 
that may have been developed for the species; the recovery plan for the 
species; articles in peer-reviewed journals; conservation plans 
developed by States and counties; scientific status surveys and 
studies; biological assessments; other unpublished materials; or 
experts' opinions or personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not be needed 
for recovery of the species. Areas that are important to the 
conservation of the species, both inside and outside the critical 
habitat designation, will continue to be subject to: (1) Conservation 
actions implemented under section 7(a)(1) of the Act; (2) regulatory 
protections afforded by the requirement in section 7(a)(2) of the Act 
for Federal agencies to ensure their actions are not likely to 
jeopardize the continued existence of any endangered or threatened 
species; and (3) the prohibitions found in the 4(d) rule. Federally 
funded or permitted projects affecting listed species outside their 
designated critical habitat areas may still result in jeopardy findings 
in some cases. These protections and conservation tools will continue 
to contribute to recovery of the species.

[[Page 92769]]

Similarly, critical habitat designations made on the basis of the best 
scientific data available at the time of designation will not control 
the direction and substance of future recovery plans, habitat 
conservation plans (HCPs), or other species conservation planning 
efforts if new information available at the time of those planning 
efforts calls for a different outcome.

Physical or Biological Features Essential to the Conservation of the 
Species

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12(b), in determining which areas we will designate as 
critical habitat from within the geographical area occupied by the 
species at the time of listing, we consider the physical or biological 
features that are essential to the conservation of the species and 
which may require special management considerations or protection. The 
regulations at 50 CFR 424.02 define ``physical or biological features 
essential to the conservation of the species'' as the features that 
occur in specific areas and that are essential to support the life-
history needs of the species, including, but not limited to, water 
characteristics, soil type, geological features, sites, prey, 
vegetation, symbiotic species, or other features. A feature may be a 
single habitat characteristic or a more complex combination of habitat 
characteristics. Features may include habitat characteristics that 
support ephemeral or dynamic habitat conditions. Features may also be 
expressed in terms relating to principles of conservation biology, such 
as patch size, distribution distances, and connectivity. For example, 
physical features essential to the conservation of the species might 
include gravel of a particular size required for spawning, alkaline 
soil for seed germination, protective cover for migration, or 
susceptibility to flooding or fire that maintains necessary early-
successional habitat characteristics. Biological features might include 
prey species, forage grasses, specific kinds or ages of trees for 
roosting or nesting, symbiotic fungi, or absence of a particular level 
of nonnative species consistent with conservation needs of the listed 
species. The features may also be combinations of habitat 
characteristics and may encompass the relationship between 
characteristics or the necessary amount of a characteristic essential 
to support the life history of the species.
    In considering whether features are essential to the conservation 
of the species, we may consider an appropriate quality, quantity, and 
spatial and temporal arrangement of habitat characteristics in the 
context of the life-history needs, condition, and status of the 
species. These characteristics include, but are not limited to, space 
for individual and population growth and for normal behavior; food, 
water, air, light, minerals, or other nutritional or physiological 
requirements; cover or shelter; sites for breeding, reproduction, or 
rearing (or development) of offspring; and habitats that are protected 
from disturbance.
    The individual needs of Pecos pupfish vary somewhat by life stage 
(egg, hatchling, juvenile, adult); however, as an aquatic species, 
Pecos pupfish need adequate water quantity and water quality to meet 
their resource functions, which include feeding, growth, survival, and 
breeding. The Pecos pupfish occurs in a variety of aquatic environments 
including wetlands, sinkholes, impoundments, streams, springs, and 
rivers, specifically the Pecos River mainstem (Hoagstrom and Brooks 
1999, pp. 14-16; Collyer et al. 2015, p. 182). All life stages of the 
Pecos pupfish prefer environments with little to no water flow, and, in 
areas with flows, they typically occupy pools and shallow runs and 
riffles (Hoagstrom and Brooks 1999, pp. 36, 45). Pecos pupfish tolerate 
high salinity (less than 35,000 mg/L) and low dissolved oxygen (greater 
than 2.5 mg/L), and while the specific thermal tolerance of Pecos 
pupfish is unknown, studies examining thermal tolerance of other 
pupfish found tolerance to range from below 0 [deg]C to 45 [deg]C (23 
[deg]F to 113 [deg]F) (Bennett and Beitinger 1997, pp. 81-85; Hoagstrom 
and Brooks 1999, pp. 21, 31; Propst 1999, pp. 67-68). However, data 
collected in studies of desert pupfish found that temperatures above 
42.7 [deg]C (108.9 [deg]F) may be lethal (Schoenherr and Feldmeth 1992, 
p. 50; BEEC 2010, p. 8). These physical conditions (dissolved oxygen, 
salinity, and temperature) can be greatly affected by spring discharge 
and other flow parameters (Kodric-Brown 1975, pp. 3, 6). Overwintering 
juvenile and adult Pecos pupfish need dense aquatic vegetation and 
flocculent materials (such as fine detritus or non-living organic 
matter) in the substrate (Kodric-Brown 1977, p. 752; Hoagstrom et al. 
2015, p. 17). Therefore, sufficient water quality and water quantity 
that provides the appropriate conditions for the Pecos pupfish is 
essential to the species.
    Spawning adult Pecos pupfish require slow-moving waters that are 
less than 2 m (6.56 ft) deep, and in areas with topographic diversity 
that include a variety of underwater features such as crevices, 
boulders, large rocks, scattered pebbles, and aquatic plants that are 
used for oviposition sites (Kodric-Brown 1975, p. 35; 1977, pp. 750-
751, 753-756, and 761-762). Rocky embankments appear to be the most 
desirable breeding substrate, and the density of territorial males is 
highest in dense patches of aquatic vegetation, and lowest in flat 
silty areas with isolated rocks (Kodric-Brown 1975, pp. 20, 34-35). 
Female Pecos pupfish lay individual eggs that adhere to spawning 
substrate, such as vegetation or rocks (Kodric-Brown 1977, pp. 751, 
761-762, 764). Therefore, habitat with crevices, boulders, large rocks, 
scattered pebbles, and aquatic plants is essential to the species.
    The introduction of the nonnative, invasive sheepshead minnow has 
the potential to negatively affect Pecos pupfish through hybridization 
(Echelle et al. 2003b, entire; Echelle and Connor 1989, pp. 725-726). 
Hybridization eventually leads to the loss of non-introgressed 
(genetically pure) Pecos pupfish in the area of introgression (Echelle 
and Connor 1989, p. 725; Echelle et al. 2003b, entire). Sheepshead 
minnow also outcompete the Pecos pupfish for resources (Echelle et al. 
2003b, entire; Echelle and Connor 1989, pp. 725-726). Therefore, the 
absence of this nonnative invasive species is essential to the Pecos 
pupfish. Bait bucket transfers of sheepshead minnow are most likely in 
the Upper Pecos Unit. Bait bucket transfers are highly unlikely to 
occur in any of the other AUs as these generally are either well 
controlled or do not contain game fish species. As such, the most 
likely route for sheepshead minnow introgression would be from the 
Upper Pecos River AU to the Salt Creek Wilderness and Middle Tract 
Wetlands, which are both hydrologically connected to the upper Pecos 
River during flooding events, allowing for potential movement of 
sheepshead minnow into these off-channel habitats.

Summary of Essential Physical or Biological Features

    We derive the specific physical or biological features essential to 
the conservation of Pecos pupfish from studies of the species' habitat, 
ecology, and life history as described below. Additional information 
can be found in the SSA report (Service 2024, entire; available on 
https://www.regulations.gov under Docket No. FWS-R2-ES-2024-0143). We 
have determined that the following physical or biological features are 
essential to the conservation of Pecos pupfish:
    (1) Water quality parameters that support all life stages of the 
Pecos pupfish, including:

[[Page 92770]]

    (a) Absence of pollutants, or a level of contaminants low enough 
that it does not negatively impact necessary water quality conditions 
for Pecos pupfish individuals;
    (b) Salinity less than 35,000 mg/L;
    (c) Temperature less than 42.7 [deg]C (108.9 [deg]F); and
    (d) Dissolved oxygen greater than 2.5 mg/L.
    (2) Sufficient water quantity parameters that support all life 
stages of the Pecos pupfish, including:
    (a) Permanent water in some area of habitat; and
    (b) Water depth less than 2 m (6.56 ft) deep to allow for thermal 
refugia and breeding.
    (3) Presence of silt-free underwater features such as crevices, 
boulders, large rocks, scattered pebbles, and aquatic plants that are 
used for egg deposition.
    (4) Absence of nonnative invasive sheepshead minnow.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing contain features which are essential to the conservation of 
the species and which may require special management considerations or 
protection. The features essential to the conservation of this species 
may require special management considerations or protection to reduce 
the following threats: introduction of sheepshead minnow, habitat 
degradation due to declines in water quantity and water quality, and 
habitat fragmentation.
    Management activities that could ameliorate these threats include, 
but are not limited to: (1) construction and maintenance of barriers 
that prevent the spread of sheepshead minnow; (2) enforcement of 
existing State regulatory mechanisms that prohibit bait-bucket releases 
of sheepshead minnow in New Mexico and Texas; (3) active management of 
wetlands to provide for adequate water quantity and flow; (4) securing 
water rights to provide long-term spring flows; (5) monitoring and 
preventing water quality impairments from upland sources such as 
agricultural runoff and industrial pollutants; and (6) survey and 
monitoring to further characterize the extent and spread of 
hybridization with sheepshead minnows.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available to designate critical habitat. In accordance 
with the Act and our implementing regulations at 50 CFR 424.12(b), we 
review available information pertaining to the habitat requirements of 
the species and identify specific areas within the geographical area 
occupied by the species at the time of listing and any specific areas 
outside the geographical area occupied by the species to be considered 
for designation as critical habitat. We are not currently proposing to 
designate any areas outside the geographical area occupied by the 
species because (1) we have not identified any unoccupied areas that 
meet the definition of critical habitat, and (2) we have determined 
that the occupied areas are sufficient to conserve the species.
    We anticipate that recovery will require conserving the genetic 
diversity of extant populations across the species' current range and 
maintaining and, where necessary, improving habitat and habitat 
connectivity to ensure the long-term viability of the Pecos pupfish. 
This proposed critical habitat designation delineates the habitat that 
is physically occupied and used by the species rather than delineating 
all land or aquatic areas that influence the species. We have 
determined that the areas currently occupied by the Pecos pupfish would 
maintain the species' resiliency, redundancy, and representation and 
are sufficient to conserve the species. Therefore, we are not currently 
proposing to designate any areas outside the geographical area occupied 
by the species. Sources of data for this proposed critical habitat 
include multiple databases maintained by universities and State 
agencies, scientific and agency reports, and numerous survey reports 
throughout the species' range (Service 2024, pp. 28-34).
    In summary, for areas within the geographical area occupied by the 
species at the time of listing, we delineated critical habitat unit 
boundaries using the following criteria:
    (1) We delineated areas within the historical range that had 
positive survey data between the year 1992 and the time of listing (see 
Service 2024).
    (2) We terminated stream segments at barriers, confluences, areas 
where genetically pure Pecos pupfish have been extirpated, other 
obvious unsuitable habitat, or a location selected based on expert 
knowledge of a lack of presence.
    (3) We included connecting stream segments between occupied stream 
segments as long as the inclusion does not disagree with criterion (2) 
and there are no data to suggest that the Pecos pupfish is not present.
    When determining proposed critical habitat boundaries, we made 
every effort to avoid including developed areas such as lands covered 
by buildings, pavement, and other structures because such lands lack 
physical or biological features necessary for Pecos pupfish. The scale 
of the maps we prepared under the parameters for publication within the 
Code of Federal Regulations may not reflect the exclusion of such 
developed lands. Any such lands inadvertently left inside critical 
habitat boundaries shown on the maps of this proposed rule have been 
excluded by text in the proposed rule and are not proposed for 
designation as critical habitat. Therefore, if the critical habitat is 
finalized as proposed, a Federal action involving these lands would not 
trigger section 7 consultation with respect to critical habitat and the 
requirement of no adverse modification unless the specific action would 
affect the physical or biological features in the adjacent critical 
habitat.
    The proposed critical habitat designation is defined by the map or 
maps, as modified by any accompanying regulatory text, presented at the 
end of this document under Proposed Regulation Promulgation.

Proposed Critical Habitat Designation

    We are proposing to designate five units of critical habitat for 
Pecos pupfish: 136.12 river mi (219.06 river km) of instream habitat 
(to the ordinary high water mark, not including riparian areas) and 
26,555.54 acres (10,746.64 ha) of lands that encompass numerous 
isolated sinkholes and wetland areas. The critical habitat areas we 
describe below constitute our current best assessment of areas that 
meet the definition of critical habitat for Pecos pupfish.
    The five areas we propose as critical habitat are: (1) Upper Pecos 
River Unit; (2) Salt Creek Wilderness Unit; (3) Bitter Lake Unit; (4) 
BLM Overflow Wetlands/Bottomless Lakes Unit; and (5) Salt Creek (TX) 
Unit. Table 5 shows the proposed critical habitat units and the 
approximate area of each unit. The Bitter Lake Unit includes both the 
Bitter Creek Drainage and Bitter Lake NWR Middle Tract Wetlands AUs 
(see table 2 for a list of the AUs). The BLM Overflow Wetlands/
Bottomless Lakes Unit includes both the Bottomless Lakes State Park and 
BLM Overflow Wetlands and Lea Lake AUs. Two AUs from the SSA report, 
the Middle Pecos River and Lower Pecos River units, are not proposed as 
critical habitat units because no extant genetically pure Pecos pupfish 
remain in these units.

[[Page 92771]]



                           Table 5--Proposed Critical Habitat Units for Pecos Pupfish
                   [Area estimates reflect all land within critical habitat unit boundaries.]
----------------------------------------------------------------------------------------------------------------
                                                                                       Length of unit in river
       Critical habitat unit                Occupied?        Land ownership by type   miles (km) or unit size in
                                                                                              acres (ha)
----------------------------------------------------------------------------------------------------------------
1. Upper Pecos River...............  Yes...................  Federal...............  32.61 river mi (52.48 km).
                                     Yes...................  State.................  4.86 river mi (7.82 km).
                                     Yes...................  Private...............  84.41 river mi (135.84 km).
2. Salt Creek Wilderness...........  Yes...................  Federal...............  5,428.74 acres (2,196.93
                                     Yes...................                           ha).
3. Bitter Lake.....................  Yes...................  Federal...............  9,663.15 acres (3,910.54
                                     Yes...................  State.................   ha).
                                     Yes...................  Private...............  87.87 acres (35.56 ha).
                                                                                     2,221.88 acres (899.16 ha).
4. BLM Overflow Wetlands/Bottomless  Yes...................  Federal...............  1,784 acres (721.96 ha).
 Lakes.                              Yes...................  State.................  1,854.78 acres (750.60 ha).
                                     Yes...................  Private...............  5,515.12 acres (2,231.89
                                                                                      ha).
5. Salt Creek (TX).................  Yes...................  Private...............  14.24 river mi (22.92 km)
                                                                                    ----------------------------
    Total..........................  ......................  ......................  136.12 river mi (219.06
                                                                                      km).
                                                                                     26,555.54 acres (10,746.64
                                                                                      ha).
----------------------------------------------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding.

    We present brief descriptions of all units, and reasons why they 
meet the definition of critical habitat for Pecos pupfish, below.

Unit 1: Upper Pecos River

    The Upper Pecos River Unit consists of 121.88 river mi (196.15 km). 
The Upper Pecos River Unit begins at Bosque Draw in Chaves County, New 
Mexico, and extends south on the Pecos River to (but not including) 
Brantley Lake, in Eddy County, New Mexico. The entire unit is currently 
occupied by the species and supports all of the physical and biological 
features (PBFs) essential to the conservation of the species. Ownership 
of the adjacent riparian areas is 26.76 percent Federal, 3.99 percent 
State, and 69.26 percent private.
    Based on prior introductions, without barriers, sheepshead minnow 
could spread through all the accessible portions of the Upper Pecos 
River Unit. In addition, this unit is subject to regular severe low and 
intermittent flows. Conservation measures are in place by the BOR under 
a biological opinion to minimize river intermittency for the federally 
threatened Pecos bluntnose shiner. These measures buffer the threat of 
river drying for Pecos bluntnose shiner and, by extension, Pecos 
pupfish.
    The entirety of this unit has ongoing water quality concerns and is 
considered impaired. Water availability in the unit is primarily 
influenced by the management of the upstream dam at Fort Sumner. River 
flows downstream of Bitter Lake NWR are influenced by groundwater 
pumping by PVACD water users and return flows from crop irrigation. 
Therefore, special management considerations may be required to 
maintain barriers that prevent the spread of sheepshead minnow into the 
upper Pecos River, enforce prohibitions of bait-bucket releases of 
sheepshead minnow in New Mexico and Texas, maintain adequate water 
quantity and flow, monitor and prevent water quality impairments from 
upland sources such as agricultural runoff and industrial pollutants, 
routinely monitor for Pecos pupfish and to document the extent and 
spread of hybridization with sheepshead minnows. The Upper Pecos River 
Unit is occupied by two federally listed species, the threatened Pecos 
sunflower (Helianthus paradoxus) and the endangered Pecos bluntnose 
shiner. There is a complete overlap with designated critical habitat 
for the Pecos bluntnose shiner (see 50 CFR 17.95(e); 52 FR 5295, 
February 20, 1987).

Unit 2: Salt Creek Wilderness

    The Salt Creek Wilderness Unit contains Salt Creek (New Mexico 
(NM)) and four sinkholes within 5,428.74 acres (2,196.93 ha) of land 
between Cottonwood Road and the confluence with the Pecos River in 
Chaves County, New Mexico. Areas within this proposed critical habitat 
unit are limited to the sinkholes and wetlands areas, and do not 
include the lands adjacent to the wetted areas. The wetted areas within 
this unit are currently occupied by the species and support all of the 
PBFs essential to the conservation of the species. Ownership of the 
adjacent riparian areas is 100 percent Federal, primarily encompassing 
the Refuge North Tract of Bitter Lake NWR. Salt Creek (NM) is an 
ephemeral stream with permanent water in deeper pools along the stream 
course. There is a low risk of introgression with sheepshead minnow 
into the sinkholes within the Salt Creek Wilderness Unit, as they are 
isolated from the Pecos River. Although fish remain extant at several 
locations in the unit, the extent of habitat is small, and Salt Creek 
(NM) is subject to mortality events. Therefore, special management 
considerations may be required to enforce prohibitions of bait-bucket 
releases of sheepshead minnow in New Mexico and Texas, maintain fish 
barriers to prevent spread of sheepshead minnow, maintain adequate 
water quantity and flow in Salt Creek (NM), monitor and prevent water 
quality impairments from upland sources such as agricultural runoff and 
industrial pollutants, and routinely monitor for Pecos pupfish to 
document the spread and extent of hybridization with sheepshead 
minnows. There is no overlap with any designated critical habitat for 
other listed species.

Unit 3: Bitter Lake

    The Bitter Lake Unit contains Bitter Creek and numerous isolated 
sinkholes, spring ditches, managed and natural wetlands, and oxbows of 
the Pecos River within 11,972.90 acres (4,845.26 ha) of land between 
Bitter Lake Road in the north and Miami Road in the South in Chaves 
County, New Mexico. All of the wetted areas in the entire unit are 
currently occupied by the species and support all of the PBFs essential 
to the conservation of the species. Ownership of the adjacent riparian 
areas is 80.71 percent Federal, 0.73 percent State, and 18.56 percent 
private. Most of the unit falls within Bitter Lake NWR. While the 
sinkholes in the Bitter Lake Unit are isolated and well protected from 
sheepshead minnow introgression, there

[[Page 92772]]

is a potential to introduce sheepshead minnow to the managed wetlands 
within Bitter Lake NWR if the fish barriers are overtopped in high flow 
events. Water quality surveys have not detected any impairment to the 
aquatic environments in the unit. Furthermore, most of the unit is 
within Bitter Lake NWR, which protects the unit from direct surface 
contamination.
    The water in Bitter Creek is supplemented by precipitation during 
wet seasons or years, and during drought years, when precipitation is 
not sufficient to maintain surface flows, portions of Bitter Creek dry 
out. Therefore, special management considerations may be required to 
maintain adequate flows in Bitter Creek to maintain habitat 
connectivity and for routine monitoring for Pecos pupfish. The Bitter 
Lake Unit is occupied by seven federally listed species, the threatened 
Wright's marsh thistle (Cirsium wrightii), threatened Pecos sunflower, 
endangered Noel's amphipod (Gammarus desperatus), endangered Roswell 
springsnail (Pyrgulopsis roswellensis), endangered Pecos assiminea 
(Assiminea pecos), endangered Pecos gambusia (Gambusia nobilis), and 
the endangered Koster's springsnail (Juturnia kosteri). There is a 
complete overlap with designated critical habitat for the Wright's 
marsh thistle (see 50 CFR 17.96(a); 88 FR 25208, May 25, 2023), Noel's 
amphipod (see 50 CFR 17.95(h); 76 FR 33036, June 7, 2011), Roswell 
springsnail (see 50 CFR 17.95(f); 77 FR 33036, June 7, 2011), Pecos 
assiminea (see 50 CFR 17.95(f); 76 FR 33036, June 7, 2011), and 
Koster's springsnail (see 50 CFR 17.95(f); 76 FR 33036, June 7, 2011).

Unit 4: BLM Overflow Wetlands/Bottomless Lakes

    The BLM Overflow Wetlands/Bottomless Lakes Unit contains a wetland 
and several sinkholes within 9,153.90 acres (3,704.45 ha) of land in 
Chaves County, New Mexico. This unit is east of the Pecos River and 
between Highway 380 in the north and the approximate southern border of 
the BLM Overflow Wetlands ACEC in the South. The wetlands and sinkholes 
within this unit are currently occupied by the species and support all 
of the PBFs essential to the conservation of the species. Ownership of 
the adjacent riparian areas is 19.49 percent Federal, 20.26 percent 
State, and 60.25 percent private. The majority of occupied habitat 
within this unit falls within Bottomless Lakes State Park and the BLM 
Overflow Wetlands ACEC.
    Although the BLM Overflow Wetlands contain constructed and 
maintained fish barriers, a severe flood could overtop or wash out 
these barriers, presenting a risk from sheepshead minnow, which are 
present near this population. The isolated sinkholes and wetlands 
within Bottomless Lakes State Park are well protected from sheepshead 
minnow introgression because (1) they do not contain game fish species 
and (2) fishing with baitfish is illegal, making these areas a low risk 
of bait-bucket releases. In 2020, a complete loss of pupfish in Upper 
Figure 8 Lake sinkhole is speculated to have been caused by a golden 
algae outbreak, but the actual causes are unknown. Therefore, special 
management considerations may be required for routine monitoring for 
Pecos pupfish to document the extent and spread of hybridization with 
sheepshead minnows. The BLM Overflow Wetlands/Bottomless Lakes Unit is 
occupied by one federally listed species, the threatened Pecos 
sunflower.

Unit 5: Salt Creek (TX)

    The Salt Creek (TX) Unit consists of 14.24 river mi (22.92 km) in 
Culberson and Reeves Counties, Texas. The unit begins at RM 2119 in 
Culberson County, Texas, and extends northeast on Salt Creek to RM 652 
in Reeves County, Texas. Ownership of the adjacent riparian areas is 
entirely under private ownership.
    Pecos pupfish from the lower reach of the Salt Creek (TX) Unit, 
near the confluence with the Pecos River, were confirmed introgressed 
with sheepshead minnow, though an unidentified physical barrier appears 
to have limited the spread of introgressed fish further upstream. The 
entirety of this unit has ongoing water quality concerns and is 
considered impaired due to contaminants introduced from upland sources 
such as agricultural runoff and industrial pollutants from oil and gas 
extraction. While during wet seasons or years, the water in Salt Creek 
(TX) is supplemented by precipitation, during drought years, the 
precipitation is not sufficient to maintain surface flows. Therefore, 
special management considerations may be required to maintain barriers 
that prevent the spread of sheepshead minnow into the upper portion of 
Salt Creek (TX), enforce prohibitions of bait-bucket releases of 
sheepshead minnow in New Mexico and Texas, maintain adequate water 
quantity and flow, and monitor and prevent water quality impairments 
from upland sources such as agricultural runoff and industrial 
pollutants, and to survey and monitor the extent and spread of 
hybridization with sheepshead minnows. There is no overlap with any 
designated critical habitat for other listed species in the Salt Creek 
(TX) Unit.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they authorize, fund, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species. In 
addition, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action which is likely to 
jeopardize the continued existence of any species proposed to be listed 
under the Act or result in the destruction or adverse modification of 
proposed critical habitat.
    Destruction or adverse modification means a direct or indirect 
alteration that appreciably diminishes the value of critical habitat as 
a whole for the conservation of a listed species (50 CFR 402.02).
    Compliance with the requirements of section 7(a)(2) is documented 
through our issuance of:
    (1) A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    (2) A biological opinion for Federal actions that may affect, and 
are likely to adversely affect, listed species or critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species and/or 
destroy or adversely modify critical habitat, we provide reasonable and 
prudent alternatives to the project, if any are identifiable, that 
would avoid the likelihood of jeopardy and/or destruction or adverse 
modification of critical habitat. We define ``reasonable and prudent 
alternatives'' (at 50 CFR 402.02) as alternative actions identified 
during formal consultation that:
    (1) Can be implemented in a manner consistent with the intended 
purpose of the action,
    (2) Can be implemented consistent with the scope of the Federal 
agency's legal authority and jurisdiction,
    (3) Are economically and technologically feasible, and
    (4) Would, in the Service Director's opinion, avoid the likelihood 
of jeopardizing the continued existence of the listed species or avoid 
the likelihood of destroying or adversely modifying critical habitat.

[[Page 92773]]

    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 set forth requirements for Federal 
agencies to reinitiate consultation. Reinitiation of consultation is 
required and shall be requested by the Federal agency, where 
discretionary Federal involvement or control over the action has been 
retained or is authorized by law and: (1) If the amount or extent of 
taking specified in the incidental take statement is exceeded; (2) if 
new information reveals effects of the action that may affect listed 
species or critical habitat in a manner or to an extent not previously 
considered; (3) if the identified action is subsequently modified in a 
manner that causes an effect to the listed species or critical habitat 
that was not considered in the biological opinion or written 
concurrence; or (4) if a new species is listed or critical habitat 
designated that may be affected by the identified action. As provided 
in 50 CFR 402.16, the requirement to reinitiate consultations for new 
species listings or critical habitat designation does not apply to 
certain agency actions (e.g., land management plans issued by the 
Bureau of Land Management in certain circumstances).

Destruction or Adverse Modification of Critical Habitat

    The key factor related to the destruction or adverse modification 
determination is whether implementation of the proposed Federal action 
directly or indirectly alters the designated critical habitat in a way 
that appreciably diminishes the value of the critical habitat for the 
conservation of the listed species. As discussed above, the role of 
critical habitat is to support physical or biological features 
essential to the conservation of a listed species and provide for the 
conservation of the species.
    Section 4(b)(8) of the Act requires that our Federal Register 
documents ``shall, to the maximum extent practicable also include a 
brief description and evaluation of those activities (whether public or 
private) which, in the opinion of the Secretary, if undertaken may 
adversely modify [critical] habitat, or may be affected by such 
designation.'' Activities that may be affected by designation of 
critical habitat for the Pecos pupfish include those that may affect 
the physical or biological features of the proposed critical habitat 
(see Physical or Biological Features Essential to the Conservation of 
the Species).

Exemptions

Application of Section 4(a)(3) of the Act

    Section 4(a)(3)(B)(i) of the Act provides that the Secretary shall 
not designate as critical habitat any lands or other geographical areas 
owned or controlled by the Department of Defense (DoD), or designated 
for its use, that are subject to an integrated natural resources 
management plan (INRMP) prepared under section 101 of the Sikes Act 
Improvement Act of 1997 (16 U.S.C. 670a), if the Secretary determines 
in writing that such plan provides a benefit to the species for which 
critical habitat is proposed for designation. No DoD lands with a 
completed INRMP are within the proposed critical habitat designation.

Consideration of Impacts Under Section 4(b)(2) of the Act

    Section 4(b)(2) of the Act states that the Secretary shall 
designate and make revisions to critical habitat on the basis of the 
best available scientific data after taking into consideration the 
economic impact, national security impact, and any other relevant 
impact of specifying any particular area as critical habitat. The 
Secretary may exclude an area from critical habitat if the benefits of 
exclusion outweigh those of inclusion, so long as exclusion will not 
result in the extinction of the species concerned. Exclusion decisions 
are governed by the regulations at 50 CFR 424.19 and the ``Policy 
Regarding Implementation of Section 4(b)(2) of the Endangered Species 
Act'' (hereafter, the ``2016 Policy''; 81 FR 7226, February 11, 2016), 
both of which were developed jointly with the National Marine Fisheries 
Service (NMFS). We also refer to a 2008 Department of the Interior 
Solicitor's opinion entitled ``The Secretary's Authority to Exclude 
Areas from a Critical Habitat Designation under Section 4(b)(2) of the 
Endangered Species Act'' (M-37016).
    In considering whether to exclude a particular area from the 
designation, we identify the benefits of including the area in the 
designation, identify the benefits of excluding the area from the 
designation, and evaluate whether the benefits of exclusion outweigh 
the benefits of inclusion. If the analysis indicates that the benefits 
of exclusion outweigh the benefits of inclusion, the Secretary may 
exercise discretion to exclude the area only if such exclusion would 
not result in the extinction of the species. In making the 
determination to exclude a particular area, the statute on its face, as 
well as the legislative history, are clear that the Secretary has broad 
discretion regarding which factor(s) to use and how much weight to give 
to any factor. In our final rules, we explain any decision to exclude 
areas, as well as decisions not to exclude, to make clear the rational 
basis for our decision. We describe below the process that we use for 
taking into consideration each category of impacts and any initial 
analyses of the relevant impacts.

Consideration of Economic Impacts

    Section 4(b)(2) of the Act and its implementing regulations require 
that we consider the economic impact that may result from a designation 
of critical habitat. To assess the probable economic impacts of a 
designation, we must first evaluate specific land uses or activities 
and projects that may occur in the area of the critical habitat. We 
then must evaluate the impacts that a specific critical habitat 
designation may have on restricting or modifying specific land uses or 
activities for the benefit of the species and its habitat within the 
areas proposed. We then identify which conservation efforts may be the 
result of the species being listed under the Act versus those 
attributed solely to the designation of critical habitat for this 
particular species. The probable economic impact of a proposed critical 
habitat designation is analyzed by comparing scenarios both ``with 
critical habitat'' and ``without critical habitat.''
    The ``without critical habitat'' scenario represents the baseline 
for the analysis, which includes the existing regulatory and socio-
economic burden imposed on landowners, managers, or other resource 
users potentially affected by the designation of critical habitat 
(e.g., under the Federal listing as well as other Federal, State, and 
local regulations). Therefore, the baseline represents the costs of all 
efforts attributable to the listing of the species under the Act (i.e., 
conservation of the species and its habitat incurred regardless of 
whether critical habitat is designated). The ``with critical habitat'' 
scenario describes the incremental impacts associated specifically with 
the designation of critical habitat for the species. The incremental 
conservation efforts and associated impacts would not be expected 
without the designation of critical habitat for the species. In other 
words, the incremental costs are those attributable solely to the 
designation of critical habitat, above and beyond the baseline costs. 
These are the costs we use when evaluating the benefits of inclusion 
and exclusion of particular areas from the final designation of 
critical habitat should we

[[Page 92774]]

choose to conduct a discretionary section 4(b)(2) exclusion analysis.
    Executive Order (E.O.) 14094 amends and reaffirms E.O. 12866 and 
E.O. 13563 and directs Federal agencies to assess the costs and 
benefits of available regulatory alternatives in quantitative (to the 
extent feasible) and qualitative terms. Consistent with the E.O. 
regulatory analysis requirements, our effects analysis under the Act 
may take into consideration impacts to both directly and indirectly 
affected entities, where practicable and reasonable. If sufficient data 
are available, we assess to the extent practicable the probable impacts 
to both directly and indirectly affected entities. Section 3(f) of E.O. 
12866 identifies four criteria when a regulation is considered a 
``significant regulatory action'' and requires additional analysis, 
review, and approval if met. The criterion relevant here is whether the 
designation of critical habitat may have an economic effect of $200 
million or more in any given year (section 3(f)(1) of E.O 12866 as 
amended by E.O. 14094). Therefore, our consideration of economic 
impacts uses a screening analysis to assess whether a designation of 
critical habitat for Pecos pupfish is likely to exceed the threshold 
for a regulatory action significant under section 3(f)(1) of E.O. 
12866, as amended by E.O. 14094.
    For this particular designation, we developed an incremental 
effects memorandum (IEM) considering the probable incremental economic 
impacts that may result from this proposed designation of critical 
habitat. The information contained in our IEM was then used to develop 
a screening analysis of the probable effects of the designation of 
critical habitat for the Pecos pupfish (Industrial Economics, Inc. 
(IEc) 2024; entire). We began by conducting a screening analysis of the 
proposed designation of critical habitat in order to focus our analysis 
on the key factors that are likely to result in incremental economic 
impacts. The purpose of the screening analysis is to filter out 
particular geographical areas of critical habitat that are already 
subject to such protections and are, therefore, unlikely to incur 
incremental economic impacts. In particular, the screening analysis 
considers baseline costs (i.e., absent critical habitat designation) 
and includes any probable incremental economic impacts where land and 
water use may already be subject to conservation plans, land management 
plans, best management practices, or regulations that protect the 
habitat area as a result of the Federal listing status of the species. 
Ultimately, the screening analysis allows us to focus our analysis on 
evaluating the specific areas or sectors that may incur probable 
incremental economic impacts as a result of the designation. The 
presence of the listed species in occupied areas of critical habitat 
means that any destruction or adverse modification of those areas is 
also likely to jeopardize the continued existence of the species. 
Therefore, designating occupied areas as critical habitat typically 
causes little if any incremental impacts above and beyond the impacts 
of listing the species. As a result, we generally focus the screening 
analysis on areas of unoccupied critical habitat (unoccupied units or 
unoccupied areas within occupied units). Overall, the screening 
analysis assesses whether designation of critical habitat is likely to 
result in any additional management or conservation efforts that may 
incur incremental economic impacts. This screening analysis combined 
with the information contained in our IEM constitute what we consider 
to be our economic analysis of the proposed critical habitat 
designation for the Pecos pupfish and is summarized in the narrative 
below.
    As part of our screening analysis, we considered the types of 
economic activities that are likely to occur within the areas likely 
affected by the critical habitat designation. In our evaluation of the 
probable incremental economic impacts that may result from the proposed 
designation of critical habitat for the Pecos pupfish, first we 
identified, in the IEM dated March 26, 2024, probable incremental 
economic impacts associated with the following categories of 
activities: (1) Federal lands management (BLM, Natural Resources 
Conservation Service, BOR, and our NWR System), (2) prescribed fire 
projects, (3) pipeline and utility crossings, (4) watershed restoration 
activities, (5) road maintenance and bridge replacement maintenance, 
(6) pesticide use, (7) construction of recreation improvements and 
management of recreation activities, (8) stocking practices, (9) 
surveys and monitoring, (10) agriculture, and (11) oil and gas 
exploration and extraction. We considered each industry or category 
individually. Additionally, we considered whether their activities have 
any Federal involvement. Critical habitat designation generally will 
not affect activities that do not have any Federal involvement; under 
the Act, designation of critical habitat only affects activities 
conducted, funded, permitted, or authorized by Federal agencies. If we 
list the species, in areas where the Pecos pupfish is present, Federal 
agencies would be required to consult with the Service under section 7 
of the Act on activities they authorize, fund, or carry out that may 
affect the species. If when we list the species, we also finalize this 
proposed critical habitat designation, Federal agencies would be 
required to consider the effects of their actions on the designated 
habitat, and if the Federal action may affect critical habitat, our 
consultations would include an evaluation of measures to avoid the 
destruction or adverse modification of critical habitat.
    In our IEM, we attempted to clarify the distinction between the 
effects that would result from the species being listed and those 
attributable to the critical habitat designation (i.e., difference 
between the jeopardy and adverse modification standards) for the Pecos 
pupfish's critical habitat. Because the designation of critical habitat 
for Pecos pupfish is being proposed concurrently with the listing, it 
has been our experience that it is more difficult to discern which 
conservation efforts are attributable to the species being listed and 
those which will result solely from the designation of critical 
habitat. However, the following specific circumstances in this case 
help to inform our evaluation: (1) The essential physical or biological 
features identified for critical habitat are the same features 
essential for the life requisites of the species, and (2) any actions 
that would likely adversely affect the essential physical or biological 
features of occupied critical habitat are also likely to adversely 
affect the Pecos pupfish itself. The IEM outlines our rationale 
concerning this limited distinction between baseline conservation 
efforts and incremental impacts of the designation of critical habitat 
for this species. This evaluation of the incremental effects has been 
used as the basis to evaluate the probable incremental economic impacts 
of this proposed designation of critical habitat.
    The proposed critical habitat designation for the Pecos pupfish 
includes a total of five units, all of which are occupied by the 
species. Ownership of the riparian lands adjacent to the two proposed 
riverine units includes 32.61 river mi (52.48 km; 23.95 percent) 
Federal, 4.86 river mi (7.82 km; 3.57 percent) State, and 98.65 river 
mi (158.76 km; 72.47 percent) private. Ownership of lands that 
encompass numerous isolated sinkholes and wetland areas that are 
currently occupied by the species in three proposed units includes 
16,875.89 acres (6,829.43 ha, 63.55 percent) Federal, 1,942.65 acres 
(786.16 ha, 7.32 percent) State, and 7,737 acres (3131.05 ha, 29.14 
percent) private. In these areas, any

[[Page 92775]]

actions that may affect the Pecos pupfish or its habitats would also 
affect designated critical habitat. Three of the five proposed units 
overlap with existing critical habitat for seven other federally listed 
species, including Pecos bluntnose shiner, Koster's springsnail, Pecos 
sunflower, Noel's amphipod, Wright's marsh thistle, Roswell 
springsnail, and Pecos assiminea.
    The proposed critical habitat designation for the Pecos pupfish 
totals 136.12 river mi (219.06 river km) of instream habitat (to the 
ordinary high water mark, not including riparian areas) and 26,555.54 
acres (10,746.64 ha) of lands that encompass numerous isolated 
sinkholes and wetland areas that are currently occupied by the species 
(the sinkholes and wetlands areas, not including the lands adjacent to 
the wetted areas). In these areas any actions that may affect the 
species or its habitat would also affect designated critical habitat, 
and it is unlikely that any additional conservation efforts would be 
recommended to address the adverse modification standard over and above 
those recommended to avoid jeopardizing the continued existence of the 
Pecos pupfish. Therefore, only administrative costs are expected in 100 
percent of the proposed critical habitat designation. While this 
additional analysis will require time and resources by both the Federal 
action agency and the Service, it is believed that, in most 
circumstances, these costs would predominantly be administrative in 
nature and would not be significant.
    The entities most likely to incur incremental costs are parties to 
section 7 consultations, including Federal action agencies and, in some 
cases, third parties, most frequently State agencies or municipalities. 
Activities that we expect would be subject to consultations that may 
involve private entities as third parties are oil and gas operations 
that may occur on private lands. However, based on coordination with 
State agencies, the cost to private entities is expected to be 
relatively minor (administrative costs of less than $5,700 per 
consultation effort); therefore, they would not be significant.
    The probable incremental economic impacts of the Pecos pupfish 
critical habitat designation are expected to be limited to additional 
administrative effort as well as minor costs of conservation efforts 
resulting from a small number of future section 7 consultations. This 
limitation is due to two factors: (1) the proposed units are considered 
occupied by the Pecos pupfish, and occupied units are afforded 
significant baseline protection under the Act due to the presence of 
the listed species; and (2) the Pecos pupfish receives additional 
baseline protection from co-occurring listed species, which include 
species with overlapping critical habitat and similar resource and 
habitat needs. At approximately $5,700 or less per consultation, the 
burden resulting from designation of critical habitat for the Pecos 
pupfish, based on the anticipated annual number of consultations and 
associated consultation costs, is not expected to exceed $11,000 in 
most years. The designation is unlikely to trigger additional 
requirements under State or local regulations. Thus, the annual 
administrative burden is relatively low. Any future probable 
incremental economic impacts are not likely to exceed $200 million in 
any single year, and impacts that are concentrated in any geographical 
area are not likely as a result of this critical habitat designation.
    We are soliciting data and comments from the public on the economic 
analysis discussed above. During the development of a final 
designation, we will consider the information presented in the economic 
analysis and any additional information on economic impacts we receive 
during the public comment period to determine whether any specific 
areas should be excluded from the final critical habitat designation 
under authority of section 4(b)(2), our implementing regulations at 50 
CFR 424.19, and the 2016 Policy. We may exclude an area from critical 
habitat if we determine that the benefits of excluding the area 
outweigh the benefits of including the area, provided the exclusion 
will not result in the extinction of this species.

Consideration of National Security Impacts

    Section 4(a)(3)(B)(i) of the Act may not cover all DoD lands or 
areas that pose potential national-security concerns (e.g., a DoD 
installation that is in the process of revising its INRMP for a newly 
listed species or a species previously not covered). If a particular 
area is not covered under section 4(a)(3)(B)(i), then national-security 
or homeland-security concerns are not a factor in the process of 
determining what areas meet the definition of ``critical habitat.'' 
However, we must still consider impacts on national security, including 
homeland security, on those lands or areas not covered by section 
4(a)(3)(B)(i) because section 4(b)(2) requires us to consider those 
impacts whenever it designates critical habitat. Accordingly, if DoD, 
Department of Homeland Security (DHS), or another Federal agency has 
requested exclusion based on an assertion of national-security or 
homeland-security concerns, or we have otherwise identified national-
security or homeland-security impacts from designating particular areas 
as critical habitat, we generally have reason to consider excluding 
those areas.
    However, we cannot automatically exclude requested areas. When DoD, 
DHS, or another Federal agency requests exclusion from critical habitat 
on the basis of national-security or homeland-security impacts, we must 
conduct an exclusion analysis if the Federal requester provides 
information, including a reasonably specific justification of an 
incremental impact on national security that would result from the 
designation of that specific area as critical habitat. That 
justification could include demonstration of probable impacts, such as 
impacts to ongoing border-security patrols and surveillance activities, 
or a delay in training or facility construction, as a result of 
compliance with section 7(a)(2) of the Act. If the agency requesting 
the exclusion does not provide us with a reasonably specific 
justification, we will contact the agency to recommend that it provide 
a specific justification or clarification of its concerns relative to 
the probable incremental impact that could result from the designation. 
If we conduct an exclusion analysis because the agency provides a 
reasonably specific justification or because we decide to exercise the 
discretion to conduct an exclusion analysis, we will defer to the 
expert judgment of DoD, DHS, or another Federal agency as to: (1) 
Whether activities on its lands or waters, or its activities on other 
lands or waters, have national-security or homeland-security 
implications; (2) the importance of those implications; and (3) the 
degree to which the cited implications would be adversely affected in 
the absence of an exclusion. In that circumstance, in conducting a 
discretionary section 4(b)(2) exclusion analysis, we will give great 
weight to national-security and homeland-security concerns in analyzing 
the benefits of exclusion.
    In preparing this proposal, we have determined that the lands 
within the proposed designation of critical habitat for Pecos pupfish 
are not owned or managed by the DoD or DHS, and, therefore, we 
anticipate no impact on national security or homeland security.

Consideration of Other Relevant Impacts

    Under section 4(b)(2) of the Act, we consider any other relevant 
impacts, in addition to economic impacts and

[[Page 92776]]

impacts on national security discussed above. To identify other 
relevant impacts that may affect the exclusion analysis, we consider a 
number of factors, including whether there are approved and permitted 
conservation agreements or plans covering the species in the area--such 
as safe harbor agreements (SHAs), candidate conservation agreements 
with assurances (CCAAs) or ``conservation benefit agreements'' or 
``conservation agreements'' (``CBAs'') (CBAs are a new type of 
agreement replacing SHAs and CCAAs in use after April 2024 (89 FR 
26070; April 12, 2024)), or HCPs--or whether there are non-permitted 
conservation agreements and partnerships that may be impaired by 
designation of, or exclusion from, critical habitat. In addition, we 
look at whether Tribal conservation plans or partnerships, Tribal 
resources, or government-to-government relationships of the United 
States with Tribal entities may be affected by the designation. We also 
consider any State, local, social, or other impacts that might occur 
because of the designation.

Summary of Exclusions Considered Under 4(b)(2) of the Act

    At this time, we are not considering any exclusions from the 
proposed designation based on economic impacts, national security 
impacts, or other relevant impacts--such as partnerships, management, 
or protection afforded by cooperative management efforts--under section 
4(b)(2) of the Act. Some areas within the proposed designation are 
included in the Conservation Agreement for the Pecos Pupfish between 
and among TPWD; NMDGF; New Mexico Energy, Minerals and Natural 
Resources Department; New Mexico Department of Agriculture; New Mexico 
Interstate Stream Commission; New Mexico State Land Office; BLM; and 
the Service.
    If through the public comment period we receive information that we 
determine indicates that there are economic, national security, or 
other relevant impacts from designating particular areas as critical 
habitat, then as part of developing the final designation of critical 
habitat, we will evaluate that information and may conduct a 
discretionary exclusion analysis to determine whether to exclude those 
areas under authority of section 4(b)(2) and our implementing 
regulations at 50 CFR 424.19. If we receive a request for exclusion of 
a particular area and after evaluation of supporting information we do 
not exclude, we will fully explain our decision in the final rule for 
this action. (Please see ADDRESSES, above, for instructions on how to 
submit comments).

Required Determinations

Clarity of the Proposed Rule

    We are required by E.O.s 12866 and 12988 and by the Presidential 
Memorandum of June 1, 1998, to write all rules in plain language. This 
means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help us 
revise the rulemaking, your comments should be as specific as possible. 
For example, you should tell us the numbers of the sections or 
paragraphs that are unclearly written, which sections or sentences are 
too long, the sections where you feel lists or tables would be useful, 
etc.

Regulatory Planning and Review (Executive Orders 12866, 13563 and 
14094)

    Executive Order 14094 amends and reaffirms the principles of E.O. 
12866 and E.O. 13563 and states that regulatory analysis should 
facilitate agency efforts to develop regulations that serve the public 
interest, advance statutory objectives, and are consistent with E.O.s 
12866, 13563, and 14094. Regulatory analysis, as practicable and 
appropriate, shall recognize distributive impacts and equity, to the 
extent permitted by law. E.O. 13563 emphasizes further that regulations 
must be based on the best available science and that the rulemaking 
process must allow for public participation and an open exchange of 
ideas. We have developed this proposed rule in a manner consistent with 
these requirements.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

    Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.), 
as amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (SBREFA; title II of Pub. L. 104-121, March 29, 1996.), whenever 
an agency is required to publish a notice of rulemaking for any 
proposed or final rule, it must prepare and make available for public 
comment a regulatory flexibility analysis that describes the effects of 
the rule on small entities (i.e., small businesses, small 
organizations, and small government jurisdictions). However, no 
regulatory flexibility analysis is required if the head of the agency 
certifies the rule will not have a significant economic impact on a 
substantial number of small entities. The SBREFA amended the RFA to 
require Federal agencies to provide a certification statement of the 
factual basis for certifying that the rule will not have a significant 
economic impact on a substantial number of small entities.
    According to the Small Business Administration, small entities 
include small organizations such as independent nonprofit 
organizations; small governmental jurisdictions, including school 
boards and city and town governments that serve fewer than 50,000 
residents; and small businesses (13 CFR 121.201). Small businesses 
include manufacturing and mining concerns with fewer than 500 
employees, wholesale trade entities with fewer than 100 employees, 
retail and service businesses with less than $5 million in annual 
sales, general and heavy construction businesses with less than $27.5 
million in annual business, special trade contractors doing less than 
$11.5 million in annual business, and agricultural businesses with 
annual sales less than $750,000. To determine whether potential 
economic impacts to these small entities are significant, we considered 
the types of activities that might trigger regulatory impacts under 
this designation as well as types of project modifications that may 
result. In general, the term ``significant economic impact'' is meant 
to apply to a typical small business firm's business operations.
    Under the RFA, as amended, as understood in light of recent court 
decisions, Federal agencies are required to evaluate the potential 
incremental impacts of rulemaking on those entities directly regulated 
by the rulemaking itself; in other words, the RFA does not require 
agencies to evaluate the potential impacts to indirectly regulated 
entities. The regulatory mechanism through which critical habitat 
protections are realized is section 7 of the Act, which requires 
Federal agencies, in consultation with the Service, to ensure that any 
action authorized, funded, or carried out by the agency is not likely 
to destroy or adversely modify critical habitat. Therefore, under 
section 7, only Federal action agencies are directly subject to the 
specific regulatory requirement (avoiding destruction and adverse 
modification) imposed by critical habitat designation. Consequently, 
only

[[Page 92777]]

Federal action agencies would be directly regulated if we adopt the 
proposed critical habitat designation. The RFA does not require 
evaluation of the potential impacts to entities not directly regulated. 
Moreover, Federal agencies are not small entities. Therefore, because 
no small entities would be directly regulated by this rulemaking, the 
Service certifies that, if made final as proposed, the proposed 
critical habitat designation will not have a significant economic 
impact on a substantial number of small entities.
    In summary, we have considered whether the proposed designation 
would result in a significant economic impact on a substantial number 
of small entities. For the above reasons and based on currently 
available information, we certify that, if made final, the proposed 
critical habitat designation would not have a significant economic 
impact on a substantial number of small business entities. Therefore, 
an initial regulatory flexibility analysis is not required.

Energy Supply, Distribution, or Use--Executive Order 13211

    E.O. 13211 (Actions Concerning Regulations That Significantly 
Affect Energy Supply, Distribution, or Use) requires agencies to 
prepare statements of energy effects to the extent permitted by law 
when undertaking actions identified as significant energy actions (66 
FR 28355, May 22, 2001). E.O. 13211 defines a ``significant energy 
action'' as an action that (i) meets the definition of a ``significant 
regulatory action'' under E.O. 12866, as amended by E.O. 14094, and 
(ii) is likely to have a significant adverse effect on the supply, 
distribution, or use of energy. In our economic analysis, we did not 
find that this proposed critical habitat designation would 
significantly affect energy supplies, distribution, or use. Therefore, 
this action is not a significant energy action, and no statement of 
energy effects is required.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), we make the following finding:
    (1) This proposed rule would not produce a Federal mandate. In 
general, a Federal mandate is a provision in legislation, statute, or 
regulation that would impose an enforceable duty upon State, local, or 
Tribal governments, or the private sector, and includes both ``Federal 
intergovernmental mandates'' and ``Federal private sector mandates.'' 
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal 
intergovernmental mandate'' includes a regulation that ``would impose 
an enforceable duty upon State, local, or Tribal governments'' with two 
exceptions. It excludes ``a condition of Federal assistance.'' It also 
excludes ``a duty arising from participation in a voluntary Federal 
program,'' unless the regulation ``relates to a then-existing Federal 
program under which $500,000,000 or more is provided annually to State, 
local, and Tribal governments under entitlement authority,'' if the 
provision would ``increase the stringency of conditions of assistance'' 
or ``place caps upon, or otherwise decrease, the Federal Government's 
responsibility to provide funding,'' and the State, local, or Tribal 
governments ``lack authority'' to adjust accordingly. At the time of 
enactment, these entitlement programs were Medicaid; Aid to Families 
with Dependent Children work programs; Child Nutrition; Food Stamps; 
Social Services Block Grants; Vocational Rehabilitation State Grants; 
Foster Care, Adoption Assistance, and Independent Living; Family 
Support Welfare Services; and Child Support Enforcement. ``Federal 
private sector mandate'' includes a regulation that ``would impose an 
enforceable duty upon the private sector, except (i) a condition of 
Federal assistance or (ii) a duty arising from participation in a 
voluntary Federal program.''
    The designation of critical habitat does not impose a legally 
binding duty on non-Federal Government entities or private parties. 
Under the Act, the only regulatory effect is that Federal agencies must 
ensure that their actions are not likely to destroy or adversely modify 
critical habitat under section 7. While non-Federal entities that 
receive Federal funding, assistance, or permits, or that otherwise 
require approval or authorization from a Federal agency for an action, 
may be indirectly impacted by the designation of critical habitat, the 
legally binding duty to avoid destruction or adverse modification of 
critical habitat rests squarely on the Federal agency. Furthermore, to 
the extent that non-Federal entities are indirectly impacted because 
they receive Federal assistance or participate in a voluntary Federal 
aid program, the Unfunded Mandates Reform Act would not apply, nor 
would critical habitat shift the costs of the large entitlement 
programs listed above onto State governments.
    (2) We do not believe that this proposed rule would significantly 
or uniquely affect small governments, because the lands being proposed 
for critical habitat designation are owned by the New Mexico State 
Parks, BLM, BOR, and the Service's NWR System. None of these government 
entities fits the definition of ``small government jurisdiction.'' 
Therefore, a small government agency plan is not required.

Takings--Executive Order 12630

    In accordance with E.O. 12630 (Government Actions and Interference 
with Constitutionally Protected Private Property Rights), we have 
analyzed the potential takings implications of designating critical 
habitat for Pecos pupfish in a takings implications assessment. The Act 
does not authorize the Services to regulate private actions on private 
lands or confiscate private property as a result of critical habitat 
designation. Designation of critical habitat does not affect land 
ownership, or establish any closures, or restrictions on use of or 
access to the designated areas. Furthermore, the designation of 
critical habitat does not affect landowner actions that do not require 
Federal funding or permits, nor does it preclude development of habitat 
conservation programs or issuance of incidental take permits to permit 
actions that do require Federal funding or permits to go forward. 
However, Federal agencies are prohibited from carrying out, funding, or 
authorizing actions that would destroy or adversely modify critical 
habitat. A takings implications assessment has been completed for the 
proposed designation of critical habitat for Pecos pupfish, and it 
concludes that, if adopted, this designation of critical habitat does 
not pose significant takings implications for lands within or affected 
by the designation.

Federalism--Executive Order 13132

    In accordance with E.O. 13132 (Federalism), this proposed rule does 
not have significant federalism effects. A federalism summary impact 
statement is not required. In keeping with Department of the Interior 
and Department of Commerce policy, we requested information from, and 
coordinated development of this proposed critical habitat designation 
with, appropriate State resource agencies. From a federalism 
perspective, the designation of critical habitat directly affects only 
the responsibilities of Federal agencies. The Act imposes no other 
duties with respect to critical habitat, either for States and local 
governments, or for anyone else. As a result, the proposed rule does 
not have substantial direct effects either on the States, or on the 
relationship between the Federal Government and the States, or on the 
distribution of powers and responsibilities among the various levels of 
government. The proposed

[[Page 92778]]

designation may have some benefit to these governments because the 
areas that contain the features essential to the conservation of the 
species are more clearly defined, and the physical or biological 
features of the habitat necessary for the conservation of the species 
are specifically identified. This information does not alter where and 
what federally sponsored activities may occur. However, it may assist 
State and local governments in long-range planning because they no 
longer have to wait for case-by-case section 7 consultations to occur.
    Where State and local governments require approval or authorization 
from a Federal agency for actions that may affect critical habitat, 
consultation under section 7(a)(2) of the Act would be required. While 
non-Federal entities that receive Federal funding, assistance, or 
permits, or that otherwise require approval or authorization from a 
Federal agency for an action, may be indirectly impacted by the 
designation of critical habitat, the legally binding duty to avoid 
destruction or adverse modification of critical habitat rests squarely 
on the Federal agency.

Civil Justice Reform--Executive Order 12988

    In accordance with E.O. 12988 (Civil Justice Reform), the Office of 
the Solicitor has determined that the rule would not unduly burden the 
judicial system and that it meets the requirements of sections 3(a) and 
3(b)(2) of the order. We have proposed designating critical habitat in 
accordance with the provisions of the Act. To assist the public in 
understanding the habitat needs of the species, this proposed rule 
identifies the physical or biological features essential to the 
conservation of the species. The proposed areas of critical habitat are 
presented on maps, and the proposed rule provides several options for 
the interested public to obtain more detailed location information, if 
desired.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

    This proposed rule does not contain information collection 
requirements, and a submission to the Office of Management and Budget 
(OMB) under the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et 
seq.) is not required. We may not conduct or sponsor and you are not 
required to respond to a collection of information unless it displays a 
currently valid OMB control number.

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

    Regulations adopted pursuant to section 4(a) of the Act are exempt 
from the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et 
seq.) and do not require an environmental analysis under NEPA. We 
published a rule-related notice outlining our reasons for this 
determination in the Federal Register on October 25, 1983 (48 FR 
49244). This includes listing, delisting, and reclassification rules, 
as well as critical habitat designations and species-specific 
protective regulations promulgated concurrently with a decision to list 
or reclassify a species as threatened. The courts have upheld this 
position (e.g., Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995) 
(critical habitat); Center for Biological Diversity v. U.S. Fish and 
Wildlife Service, 2005 WL 2000928 (N.D. Cal. Aug. 19, 2005) (concurrent 
4(d) rule)).
    However, when we designate as ``critical habitat'' any of the areas 
that fall within the jurisdiction of the U.S. Court of Appeals for the 
Tenth Circuit, including this designation proposed for the Pecos 
pupfish, we undertake a NEPA analysis for that critical habitat 
designation consistent with the Tenth Circuit's ruling in Catron County 
Board of Commissioners v. U.S. Fish and Wildlife Service, 75 F.3d 1429 
(10th Cir. 1996). We invite the public to comment on the extent to 
which this proposed critical habitat designation may have a significant 
impact on the human environment, or fall within one of the categorical 
exclusions for actions that have no individual or cumulative effect on 
the quality of the human environment. We will complete our analysis, in 
compliance with NEPA, before finalizing this proposed rule.

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951, May 4, 1994), E.O. 13175 (Consultation and 
Coordination with Indian Tribal Governments), the President's 
memorandum of November 30, 2022 (Uniform Standards for Tribal 
Consultation; 87 FR 74479, December 5, 2022), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with federally recognized 
Tribes and Alaska Native Corporations (ANCs) on a government-to-
government basis. In accordance with Secretary's Order 3206 of June 5, 
1997 (American Indian Tribal Rights, Federal-Tribal Trust 
Responsibilities, and the Endangered Species Act), we readily 
acknowledge our responsibilities to work directly with Tribes in 
developing programs for healthy ecosystems, to acknowledge that Tribal 
lands are not subject to the same controls as Federal public lands, to 
remain sensitive to Indian culture, and to make information available 
to Tribes. We will continue to work with relevant Tribal entities 
during the development of any final rules for the Pecos pupfish. We 
have determined that no Tribal lands fall within the boundaries of the 
proposed critical habitat for the Pecos pupfish, so no Tribal lands 
would be affected by the proposed designation.

References Cited

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

Authors

    The primary authors of this proposed rule are the staff members of 
the Fish and Wildlife Service's Species Assessment Team and the New 
Mexico Ecological Services Field Office.

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

    Accordingly, we propose to 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. In Sec.  17.11, in paragraph (h), amend the List of Endangered and 
Threatened Wildlife by adding an entry for ``Pupfish, Pecos'' in 
alphabetical order under FISHES to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

[[Page 92779]]



----------------------------------------------------------------------------------------------------------------
                                                                                              Listing citations
           Common name               Scientific name        Where listed         Status         and applicable
                                                                                                    rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
              Fishes
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
Pupfish, Pecos...................  Cyprinodon           Wherever found.....  T               [Federal Register
                                    pecosensis.                                               citation when
                                                                                              published as a
                                                                                              final rule]; 50
                                                                                              CFR 17.44(bb);
                                                                                              \4d\ 50 CFR
                                                                                              17.95(e).\CH\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

0
3. In Sec.  17.44, add paragraph (bb) to read as follows:


Sec.  17.44  Species-specific rules--fishes.

* * * * *
    (bb) Pecos pupfish (Cyprinodon pecosensis)--(1) Prohibitions. The 
following prohibitions that apply to endangered wildlife also apply to 
Pecos pupfish. Except as provided under paragraph (bb)(2) 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, as set forth at Sec.  17.21(c)(1) for endangered 
wildlife.
    (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 a 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) Exceptions from prohibitions. In regard to this species, you 
may:
    (i) Conduct activities as authorized by a permit under Sec.  17.32.
    (ii) Take, as set forth at Sec.  17.21(c)(2) through (c)(4) for 
endangered wildlife.
    (iii) Take, as set forth at Sec.  17.31(b).
    (iv) Possess and engage in other acts with unlawfully taken 
wildlife, as set forth at Sec.  17.21(d)(2) for endangered wildlife.
    (v) Take incidental to an otherwise lawful activity caused by:
    (A) Management and maintenance of ponds that satisfy Texas Parks 
and Wildlife Department (TPWD) permitting requirements and are stocked 
by TPWD with captive-bred Pecos pupfish.
    (B) Research activities conducted by holders of a valid scientific 
research permit, zoological permit, or educational display permit 
issued by TPWD on individual Pecos pupfish in ponds that are part of 
the TPWD Pecos pupfish production effort. Researchers must report 
annually to TPWD, and TPWD must annually report to the Service, the 
following information:
    (1) The nature of research performed;
    (2) The dates of fieldwork;
    (3) The number of individuals collected or captured and the methods 
used to obtain them;
    (4) A description of any accidental injuries or mortalities; and
    (5) The number of individuals from which genetic material was 
collected, the type of tissue collected, and the institution or 
location where the genetic material is being stored.
* * * * *
0
4. In Sec.  17.95, in paragraph (e), add an entry for ``Pecos Pupfish 
(Cyprinodon pecosensis)'' after the entry for ``Leon Springs Pupfish 
(Cyprinodon bovinus)'', to read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (e) Fishes.
* * * * *
Pecos Pupfish (Cyprinodon pecosensis)
    (1) Critical habitat units are depicted for Chaves and Eddy 
Counties, New Mexico, and Culberson and Reeves Counties, Texas, on the 
maps in this entry.
    (2) Within these areas, the physical or biological features 
essential to the conservation of Pecos pupfish consist of the following 
components:
    (i) Water quality parameters that support all life stages of the 
Pecos pupfish, including:
    (A) Absence of pollutants, or a level of contaminants low enough 
that it does not negatively impact necessary water quality conditions 
for Pecos pupfish individuals;
    (B) Salinity less than 35,000 mg/L;
    (C) Temperature less than 42.7 [deg]C (108.9 [deg]F); and
    (D) Dissolved oxygen greater than 2.5 mg/L.
    (ii) Sufficient water quantity parameters that support all life 
stages of the Pecos pupfish, including:
    (A) Permanent water in a portion of the habitat; and
    (B) Water depth less than 2 m (6.56 ft) deep to allow for thermal 
refugia and breeding.
    (iii) Presence of silt-free underwater features such as crevices, 
boulders, large rocks, scattered pebbles, and aquatic plants that are 
used for egg deposition.
    (iv) Absence of nonnative invasive sheepshead minnow.
    (3) Critical habitat does not include manmade structures (such as 
buildings, aqueducts, runways, roads, and other paved areas) and the 
land on which they are located existing within the legal boundaries on 
the effective date of the final rule.
    (4) Data layers defining map units were created using ESRI 
OpenStreets and Imagery basemaps, USA Federal Lands data, and the 
National Hydrography Dataset (NHD) Plus dataset. Polygons for units 2, 
3, and 4 were largely defined through heads-up digitization or land 
ownership boundaries (Unit 3, Bitter Lake NWR); acreage or mileage 
numbers in the designation came from these features. For online 
distribution, linear features in Unit 1 (the Pecos River) and Unit 5 
(Salt Creek) were converted to polygons. We used NHD polygons when 
available. When polygons were unavailable, we buffered the linear 
features by a set distance; 20 m for the lower third of unit 1, and 5 m 
for the entirety of unit 5. The boundaries of units 2, 3, and 4 that 
abutted the Pecos River were adjusted to match the new Unit 1 polygon. 
The maps in this entry, as modified by any accompanying regulatory 
text, establish the boundaries of the critical habitat designation. The 
coordinates or plot points or both on which each map is based are 
available to the public at https://www.regulations.gov under Docket No. 
FWS-R2-ES-2024-0143 and at the field office responsible for this 
designation. You may obtain field office location information by 
contacting one of the Service regional offices, the addresses of which 
are listed at 50 CFR 2.2.
    (5) Index map follows:


[[Page 92780]]


Figure 1 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (5)
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[GRAPHIC] [TIFF OMITTED] TP22NO24.003

BILLING CODE 4333-15-C
    (6) Unit 1: Upper Pecos River, Chaves and Eddy Counties, New 
Mexico.
    (i) Unit 1 consists of 121.88 river mi (196.15 km) of the upper 
Pecos River in Chaves and Eddy Counties, New Mexico, and is composed of 
lands in Federal (32.61 river mi (52.48 km)), State (4.86 river mi 
(7.82 km)), and private (84.41 river mi (135.84 km)) ownership. Unit 1 
includes river habitat up to bank full height.
    (ii) Map of Unit 1 follows:

Figure 2 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (6)(ii)
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[[Page 92781]]

[GRAPHIC] [TIFF OMITTED] TP22NO24.004

BILLING CODE 4333-15-C
    (7) Unit 2: Salt Creek Wilderness, Chaves County, New Mexico.
    (i) Unit 2 contains Salt Creek (New Mexico) and four sinkholes 
within 5,428.74 acres (2,196.93 hectares (ha)) of land in Chaves 
County, New Mexico. The wetted areas within this unit are entirely 
under Federal ownership, specifically the Service's Bitter Lake 
National Wildlife Refuge (NWR).
    (ii) Map of Unit 2 follows:

Figure 3 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (7)(ii)
BILLING CODE 4333-15-P

[[Page 92782]]

[GRAPHIC] [TIFF OMITTED] TP22NO24.005

BILLING CODE 4333-15-C
    (8) Unit 3: Bitter Lake, Chaves County, New Mexico.
    (i) Unit 3 contains Bitter Creek and numerous isolated sinkholes, 
spring ditches, managed and natural wetlands, and oxbows of the Pecos 
River within 11,972.90 acres (4,845.26 ha) of Chaves County, New 
Mexico. The unit is composed of lands in Federal (9,663.15 acres 
(3,910.54 ha)), State (87.87 acres (35.56 ha)), and private (2,221.88 
acres (899.16 ha)) ownership.
    (ii) Map of Unit 3 follows:

Figure 4 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (8)(ii)
BILLING CODE 4333-15-P

[[Page 92783]]

[GRAPHIC] [TIFF OMITTED] TP22NO24.006

BILLING CODE 4333-15-C
    (9) Unit 4: Overflow Wetlands/Bottomless Lakes, Chaves County, New 
Mexico.
    (i) Unit 4 contains a wetland and several isolated sinkholes within 
9,153.90 acres (3,704.45 ha) in Chaves County, New Mexico. The unit is 
composed of lands in Federal (1,784 acres (721.96 ha)), State (1854.78 
acres (750.60 ha)), and private (5,515.12 acres (2,231.89 ha)) 
ownership.
    (ii) Map of Unit 4 follows:

Figure 5 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (9)(ii)
BILLING CODE 4333-15-P

[[Page 92784]]

[GRAPHIC] [TIFF OMITTED] TP22NO24.007

BILLING CODE 4333-15-C
    (10) Unit 5: Salt Creek (TX), in Culberson and Reeves Counties, 
Texas.
    (i) Unit 5 consists of 14.24 river mi (23.20 km) in Culberson and 
Reeves Counties, Texas, and is composed of lands in 100 percent private 
ownership. Unit 5 includes river habitat up to bank full height.
    (ii) Map of Unit 5 follows:

Figure 6 to Pecos Pupfish (Cyprinodon pecosensis) paragraph (10)(ii)
BILLING CODE 4333-15-P

[[Page 92785]]

[GRAPHIC] [TIFF OMITTED] TP22NO24.008

BILLING CODE 4333-15-C
* * * * *

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2024-27127 Filed 11-21-24; 8:45 am]
BILLING CODE 4333-15-P