[Federal Register Volume 89, Number 119 (Thursday, June 20, 2024)]
[Proposed Rules]
[Pages 51864-51869]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-13617]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FXES1111090FEDR-245-FF09E21000]


Endangered and Threatened Wildlife and Plants; Three Species Not 
Warranted for Listing as Endangered or Threatened Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notification of findings.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce 
findings that three species are not warranted for listing as endangered 
or threatened species under the Endangered Species Act of 1973, as 
amended (Act). After a thorough review of the best available scientific 
and commercial information, we find that it is not warranted at this 
time to list the Kiamichi crayfish (Faxonius saxatilis), Rio Grande 
chub (Gila pandora), and Rio Grande sucker (Pantosteus plebeius, 
formerly Catostomus plebeius). However, we ask the public to submit to 
us at any time any new information relevant to the status of any of the 
species mentioned above or their habitats.

DATES: The findings in this document were made on June 20, 2024.

ADDRESSES: Detailed descriptions of the bases for these findings are 
available on the internet at https://www.regulations.gov under the 
following docket numbers:

------------------------------------------------------------------------
                   Species                             Docket No.
------------------------------------------------------------------------
Kiamichi crayfish............................        FWS-ES-R2-2023-0258
Rio Grande chub..............................        FWS-ES-R2-2024-0081
Rio Grande sucker............................        FWS-ES-R2-2024-0082
------------------------------------------------------------------------

    Those descriptions are also available by contacting the appropriate 
person as specified under FOR FURTHER INFORMATION CONTACT. Please 
submit any new information, materials, comments, or questions 
concerning this finding to the appropriate person, as specified under 
FOR FURTHER INFORMATION CONTACT.

FOR FURTHER INFORMATION CONTACT: 

------------------------------------------------------------------------
              Species                        Contact information
------------------------------------------------------------------------
Kiamichi crayfish.................  Ken Collins, Field Office
                                     Supervisor, Oklahoma Ecological
                                     Services Field Office, 918-382-
                                     4504, [email protected].
Rio Grande chub and Rio Grande      Shawn Sartorius, Field Supervisor,
 sucker.                             New Mexico Ecological Services
                                     Office, 505-346-2525,
                                     [email protected].
------------------------------------------------------------------------

    Individuals in the United States who are deaf, deafblind, hard of 
hearing, or have a speech disability may dial 711 (TTY, TDD, or 
TeleBraille) to access telecommunications relay services. Individuals 
outside the United States should use the relay services offered within 
their country to make international calls to the point-of-contact in 
the United States.

SUPPLEMENTARY INFORMATION:

Background

    Under section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), we 
are required to make a finding on whether or not a petitioned action is 
warranted within 12 months after receiving any petition that we have 
determined contains substantial scientific or commercial information 
indicating that the petitioned action may be warranted (``12-month 
finding''). We must make a finding that the petitioned action is: (1) 
Not warranted; (2) warranted; or (3) warranted, but precluded by other 
listing activity. We must publish a notification of these 12-month 
findings in the Federal Register.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and the implementing 
regulations at part 424 of title 50 of the Code of Federal Regulations 
(50 CFR part 424) set forth procedures for adding species to, removing 
species from, or reclassifying species on the Lists of Endangered and 
Threatened Wildlife and Plants (Lists). The Act defines ``species'' as 
including any subspecies of fish or wildlife or plants, and any 
distinct population segment of any species of vertebrate fish or 
wildlife which interbreeds when mature. The Act defines ``endangered 
species'' as any species that is in danger of extinction throughout all 
or a significant portion of its range (16 U.S.C. 1532(6)), and 
``threatened species'' as any species that is likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range (16 U.S.C. 1532(20)). Under section 
4(a)(1) of the Act, a species may be determined to be an endangered

[[Page 51865]]

species or a threatened species because of any of the following 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.
    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 
expected response by the species, and the effects of the threats--in 
light of those actions and conditions that will ameliorate the 
threats--on an individual, population, and species level. We evaluate 
each threat and its expected effects on the species, then analyze the 
cumulative effect of all of the threats on the species as a whole. We 
also consider the cumulative effect of the threats in light of those 
actions and conditions that will have positive effects on the species, 
such as any existing regulatory mechanisms or conservation efforts. The 
Secretary of the Interior determines whether the species meets the 
Act's definition of an ``endangered species'' or a ``threatened 
species'' only after conducting this cumulative analysis and describing 
the expected effect on the species now and in the foreseeable future.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis, which is 
further described in the 2009 Memorandum Opinion on the foreseeable 
future from the Department of the Interior, Office of the Solicitor (M-
37021, January 16, 2009; ``M-Opinion,'' available online at https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf). 
The foreseeable future extends as far into the future as the U.S. Fish 
and Wildlife Service and National Marine Fisheries Service 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.
    In conducting our evaluation of the five factors provided in 
section 4(a)(1) of the Act to determine whether the Kiamichi crayfish, 
Rio Grande chub, and Rio Grande sucker meet the Act's definition of 
``endangered species'' or ``threatened species,'' we considered and 
thoroughly evaluated the best scientific and commercial information 
available regarding the past, present, and future stressors and 
threats. We reviewed the petitions, information available in our files, 
and other available published and unpublished information for all of 
these species. Our evaluation may include information from recognized 
experts; Federal, State, and Tribal governments; academic institutions; 
foreign governments; private entities; and other members of the public.
    In accordance with the regulations at 50 CFR 424.14(h)(2)(i), this 
document announces the not-warranted findings on petitions to list 
three species. We have also elected to include brief summaries of the 
analyses on which these findings are based. We provide the full 
analyses, including the reasons and data on which the findings are 
based, in the decisional file for each of the three actions included in 
this document. The following is a description of the documents 
containing these analyses:
    The species assessment forms for the Kiamichi crayfish, Rio Grande 
chub, and Rio Grande sucker contain more detailed biological 
information, a thorough analysis of the listing factors, a list of 
literature cited, and an explanation of why we determined that these 
species do not meet the Act's definition of an ``endangered species'' 
or a ``threatened species.'' To inform our status reviews, we completed 
species status assessment (SSA) reports for these three species. Each 
SSA report contains a thorough review of the taxonomy, life history, 
ecology, current status, and projected future status for each species. 
This supporting information can be found on the internet at https://www.regulations.gov under the appropriate docket number (see ADDRESSES, 
above).

Kiamichi Crayfish

Previous Federal Actions
    On June 18, 2007, we received a petition from Forest Guardians (now 
WildEarth Guardians) to list 475 species, including the Kiamichi 
crayfish (Faxonius saxatilis; petitioned as Orconectes saxatilis), as 
an endangered or threatened species under the Act. On December 16, 
2009, we published a 90-day finding (74 FR 66866) that the petition 
contained substantial information indicating that listing may be 
warranted for the Kiamichi crayfish. This document constitutes our 12-
month finding on the June 18, 2007, petition to list the Kiamichi 
crayfish under the Act.
Summary of Finding
    The Kiamichi crayfish is a small crayfish, olive-brown to reddish-
brown dorsally and mostly whitish ventrally. It is distinguished 
morphologically from other crayfish species by details of its 
coloration and by structural features of sexually mature males. It also 
has been confirmed to be a distinct species through genetic analysis. 
The species was first described as Orconectes saxatilis, but, based on 
phylogenetic analyses, the genus name was changed in 2017 to Faxonius 
and that remains the currently accepted genus. The Kiamichi crayfish 
historically and currently inhabits the headwaters and larger 
tributaries of the upper Kiamichi River in southeastern Oklahoma. The 
species has been found only upstream of the community of Whitesboro in 
Le Flore County, Oklahoma.
    The Kiamichi crayfish occurs in streams with substrate that is

[[Page 51866]]

predominantly cobble, boulders, gravel, and other coarse rock. The 
species prefers riffle habitats but will shift to pool habitats during 
dry periods. The species needs stable riffles and pools, sufficient 
water quality, and sufficient water availability.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Kiamichi crayfish, and we evaluated all relevant factors under 
the five listing factors, including any regulatory mechanisms and 
conservation measures addressing these threats. The primary threats to 
the Kiamichi crayfish include water quality degradation and increases 
in water temperatures. Water quality degradation caused by low pH 
levels and elevated levels of heavy metals may be partially natural, 
and conditions may be improving based on current trends. Currently, 
water temperatures are within suitable temperature ranges for stream 
crayfish species (26-27 degrees Celsius ([deg]C) [78.8-80.6 degrees 
Fahrenheit ([deg]F)] and support all life stages of the Kiamichi 
crayfish with no negative effects. However, future climate projections 
used in concert with established relationships between air temperature 
and water temperature indicate that water temperatures are likely to 
increase progressively in the future.
    Currently, the species occupies four analysis units and the entire 
historical range. In general, streamflow does not differ significantly 
from historical conditions, and the majority of the Kiamichi crayfish 
range is on protected lands and is in a condition that supports 
resiliency of the species. The species has tolerated impaired water 
quality conditions for multiple decades, including lower pH levels and 
elevated heavy metals that may be at least partially natural. 
Currently, three analysis units are moderately resilient, and one is 
highly resilient, which we consider sufficient to provide redundancy 
for the species. In addition, the Kiamichi crayfish has sufficient 
representation because it has survived through periods of intensive 
logging and drought, has adapted to tolerate drought conditions, and 
has had no change in its range. Therefore, the threats appear to have 
low imminence and magnitude such that they are not currently having a 
significant effect on the species' current viability. Thus, after 
assessing the best available information, we conclude that the Kiamichi 
crayfish is not in danger of extinction throughout all of its range 
(i.e., endangered).
    Thus, we proceed with determining whether the species is likely to 
become endangered within the foreseeable future throughout all of its 
range (i.e., threatened). In our projected timeframe of 50 years 
(2070), streamflow, landscape condition, pH and heavy metal levels are 
not expected to change significantly from the current condition in 
either of two scenarios that we evaluated. In fact, pH and heavy metal 
levels may improve for the Kiamichi crayfish in the future.
    The primary threat considered to have a potentially significant 
effect on the Kiamichi crayfish is increased water temperatures due to 
climate change. Using processes set forth by the Intergovernmental 
Panel on Climate Change, we evaluated the Kiamichi crayfish under two 
future Representative Concentration Pathway (RCP) scenarios: Under 
scenario 1 (RCP 4.5), water temperatures do not rise to a level that 
would be negative for the species; under scenario 2 (RCP 8.5), summer 
water temperatures rise to levels that may negatively affect the 
Kiamichi crayfish periodically. However, potentially suboptimal water 
temperatures are projected to be periodic during summer months only, 
and the species is adapted to periods of drought and higher 
temperatures. Because the Kiamichi crayfish has the ability to tolerate 
drought and higher temperatures by burrowing and moving to pools, the 
species is expected to be able to tolerate these times of higher 
projected water temperatures. Overall increasing water temperatures may 
affect the species in the future, but each analysis unit will remain in 
the same overall resiliency condition as the current condition because 
of the species' ability to modify behavior. Therefore, we anticipate 
redundancy and representation to remain similar to current conditions 
into the future. After assessing the best available information, we 
conclude that the Kiamichi crayfish is not likely to become endangered 
within the foreseeable future throughout all of its range.
    We also evaluated whether the Kiamichi crayfish is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Kiamichi crayfish's range for which both (1) the 
portion is significant, and (2) the species is in danger of extinction 
in that portion, either now or within the foreseeable future. Thus, 
after assessing the best available information, we conclude that the 
Kiamichi crayfish is not in danger of extinction in a significant 
portion of its range now, or within the foreseeable future.
    After assessing the best available information, we conclude that 
the Kiamichi crayfish is not in danger of extinction or likely to 
become in danger of extinction throughout all of its range or in any 
significant portion of its range. Therefore, we find that listing the 
Kiamichi crayfish as an endangered species or threatened species under 
the Act is not warranted. A detailed discussion of the basis for this 
finding can be found in the species assessment form and other 
supporting documents, which are available on https://www.regulations.gov under docket number FWS-R2-ES-2023-0258.
Peer Review
    In accordance with our July 1, 1994, peer review policy (59 FR 
34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo 
on the Peer Review Process, we solicited independent scientific reviews 
of the information contained in the Kiamichi crayfish SSA report. The 
Service sent the SSA report to six independent peer reviewers and 
received three responses. Results of this structured peer review 
process can be found at https://www.regulations.gov under docket number 
FWS-R2-ES-2023-0258. We incorporated the results of these reviews, as 
appropriate, into the SSA report, which is the foundation for this 
finding.

Rio Grande Chub

Previous Federal Actions
    On September 27, 2013, we received a petition from WildEarth 
Guardians to list the Rio Grande chub (Gila Pandora) as an endangered 
or threatened species under the Act and designate critical habitat. On 
March 6, 2016, we published a 90-day finding (81 FR 14058) that the 
petition contained substantial information indicating that listing may 
be warranted for the Rio Grande chub. This document constitutes our 12-
month finding on the September 27, 2013, petition to list the Rio 
Grande chub under the Act.
Summary of Finding
    The Rio Grande chub is a small freshwater fish found predominantly 
in montane stream environments in the upper Rio Grande basin in north-
central New Mexico and south-central Colorado. Its range also includes 
portions of the Canadian River basin in New Mexico and the Pecos River 
basin in New Mexico and Texas. Another population may exist in the 
State of Coahuila, Mexico. The Rio Grande chub now occupies a small 
portion of its historical range in fragmented populations.
    Found in a variety of aquatic habitats, the Rio Grande chub is 
associated with low gradient streams that may

[[Page 51867]]

experience substantial variation in annual environmental conditions. 
Streams occupied by this species tend to have low to moderate water 
flow, low water depths, and a large temperature range. Like other chub 
species, the Rio Grande chub is often associated with instream 
structures. As omnivorous mid-water column feeders, the Rio Grande chub 
consumes drifting invertebrates, fish, and occasional vegetation.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Rio Grande chub, and we evaluated all relevant factors under the 
five listing factors, including any regulatory mechanisms and 
conservation measures addressing these threats. The primary threats 
affecting the Rio Grande chub's biological status include predation and 
competition from nonnative species, habitat loss and fragmentation 
caused by altered hydrology, catastrophic wildfire, and changes in 
environmental conditions due to climate change.
    We estimated the risk of extirpation for each Rio Grande chub 
population over several time frames. The threats we considered include 
catastrophic wildfire, nonnative species, and water withdrawal due to 
surface water diversion and/or groundwater pumping. There were three 
categories of risk: high, medium, and low. These categories were 
defined by the likelihood of the threat occurring and the magnitude of 
its impact on the population. High risk meant the threat was likely 
(i.e., greater than 50 percent) to occur over the given timeframe and 
the magnitude to the population was severe, potentially resulting in 
extirpation. Low risk meant a threat had a remote probability (i.e., 
less than 10 percent) of occurring and the magnitude would be minimal. 
For medium risk populations, either the threat was unlikely (i.e., less 
than 50 percent) to occur or the magnitude of impact was projected to 
be moderate, meaning there could be population declines but total 
extirpation was unlikely. First, we assessed the risk of extirpation 
for each population over the next 10 years based on the current habitat 
and demographic characteristics of each population. Since conditions 
are expected to change in the future, we next considered two future 
time steps: mid-century (i.e., 2050) and late-century (i.e., 2099). 
These projections incorporated the effects of changes in environmental 
conditions under two climate change scenarios.
    There are 53 populations of Rio Grande chub in the United States, 
which combined occupy 844 kilometers (km) (524.4 miles (mi)) of stream 
length. About 34 percent of these populations are at high risk of 
extirpation over the next 10 years. Most populations (57 percent) are 
at a medium risk of extirpation, with only 9 percent of populations at 
low risk. This risk of extirpation was primarily driven by nonnative 
species. No populations were at risk of extirpation due to stream 
dewatering and none were at high risk of extirpation due to wildfire 
over the next 10 years. Threats appear to have low imminence and 
magnitude such that they are not currently having a significant effect 
on the species' current viability. These 53 populations are distributed 
across a wide geographic area, providing redundancy from catastrophic 
events. They also occur across a range of environmental gradients, 
indicating the retention of adaptive capacity (i.e., representation). 
Thus, after assessing the best available information, we conclude that 
the Rio Grande chub is not in danger of extinction throughout all of 
its range (i.e., endangered).
    We then assessed whether extirpation risk as well as resiliency, 
redundancy, and representation would change over time. For resiliency, 
we modelled future changes in habitat suitability under two future 
Representative Concentration Pathway (RCP) scenarios: RCP4.5 and 
RCP8.5. Then we incorporated these changes in our estimation of future 
risk of extirpation for each population. Although the general trend was 
a decrease in habitat suitability over time, most populations (75 
percent) are projected to have no changes in resiliency. There was 
little projected change in extirpation risk by mid- and late-century. 
Most populations continue to be at medium risk of extirpation, although 
the risks posed by wildfire did increase over time for some 
populations. Although changes in redundancy and representation are 
anticipated should high risk populations be extirpated, the low and 
moderate risk populations will continue to be distributed across the 
species range, conferring redundancy and representation. After 
assessing the best available information, we conclude that the species 
is not likely to become endangered within the foreseeable future 
throughout all of its range.
    We also evaluated whether the Rio Grande chub is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Rio Grande chub's range for which both (1) the portion 
is significant, and (2) the species is in danger of extinction in that 
portion, either now or within the foreseeable future. Thus, after 
assessing the best available information, we conclude that the Rio 
Grande chub is not in danger of extinction in a significant portion of 
its range now, or within the foreseeable future. After assessing the 
best available information, we conclude that the Rio Grande chub is not 
in danger of extinction or likely to become in danger of extinction 
throughout all of its range or in any significant portion of its range. 
Therefore, we find that listing the Rio Grande chub as an endangered 
species or threatened species under the Act is not warranted. A 
detailed discussion of the basis for this finding can be found in the 
Rio Grande chub species assessment form and other supporting documents 
on https://www.regulations.gov under Docket No. FWS-R2-ES-2024-0081 
(see ADDRESSES, above).
Peer Review
    In accordance with our July 1, 1994, peer review policy (59 FR 
34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo 
on the Peer Review Process, we solicited independent scientific reviews 
of the information contained in the Rio Grande chub SSA report. The 
Service 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 under Docket No. FWS-R2-ES-
2024-0081. We incorporated the results of these reviews, as 
appropriate, into the SSA report, which is the foundation for this 
finding.

Rio Grande Sucker

Previous Federal Actions
    On October 3, 2014, we received a petition from WildEarth Guardians 
to list the Rio Grande sucker (Pantosteus plebeius; petitioned as 
Catostomus plebeius) as an endangered or threatened species under the 
Act and designate critical habitat. The species was originally 
described under the genus Catostomus, but has since been reclassified 
under the genus Pantosteus. On March 16, 2016, we published a 90-day 
finding (81 FR 14058) that the petition contained substantial 
information indicating that listing may be warranted for the Rio Grande 
sucker. This document constitutes our 12-month finding on the October 
3, 2014 petition to list the Rio Grande sucker under the Act.
Summary of Finding
    The Rio Grande sucker is a small freshwater fish found 
predominantly in montane stream environments in the upper Rio Grande 
basin in north-central

[[Page 51868]]

New Mexico and south-central Colorado. Its historical range in the 
United States also includes portions of the Gila, Pecos, and Mimbres 
Rivers basins. The described range of the Rio Grande sucker also 
extends into several drainage basins in northern Chihuahua, Mexico.
    Found in a variety of aquatic habitats, the Rio Grande sucker is 
associated with low gradient streams that may experience substantial 
variation in environmental conditions annually. Streams occupied by 
this species tend to have low to moderate water flow, low water depths, 
and a large temperature range. As a benthic feeder, this species is 
often found in areas with cobble and gravel substrates that support 
algal growth.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Rio Grande sucker, and we evaluated all relevant factors under 
the five listing factors, including any regulatory mechanisms and 
conservation measures addressing these threats. The primary threats 
affecting the Rio Grande sucker's biological status include predation 
and competition from nonnative species, habitat loss and fragmentation 
caused by altered hydrology, catastrophic wildfire, and changes in 
environmental conditions due to climate change.
    We estimated the risk of extirpation for each Rio Grande sucker 
population over several time frames. The threats we considered include 
catastrophic wildfire, nonnative species, and water withdrawal due to 
surface water diversion and/or groundwater pumping. We first assessed 
the risk of extirpation for each population over the next 10 years 
based on the current demographic and habitat conditions of each 
population. Since conditions are expected to change in the future, we 
next considered two future time steps: mid-century (i.e., 2050) and 
late-century (i.e., 2099). These projections incorporated the effects 
of changes in environmental conditions under two climate change 
scenarios.
    There are currently 32 populations of Rio Grande sucker in the 
United States, which combined occupy 605.7 km (376.4 mi) of stream 
length. About 38 percent of these populations are at high risk of 
extirpation over the next 10 years. Most populations (56 percent) are 
at a medium risk of extirpation, with 6 percent at low risk. The risk 
of extirpation was primarily driven by nonnative species. Over the next 
10 years, two populations were at risk of extirpation due to stream 
dewatering and none were at high risk of extirpation due to wildfire. 
There was little projected change in risk by mid- and late-century. 
Most populations continue to be at medium risk of extirpation, although 
the risks posed by wildfire did increase over time for some 
populations. Levels of risk were mostly consistent across the range of 
the species: across drainages basins, most populations were at an 
overall medium risk of extirpation across time steps and scenarios. 
Threats appear to have low imminence and magnitude such that they are 
not currently having a significant effect on the species' current 
viability. These 32 populations are distributed across a wide 
geographic area, providing redundancy from catastrophic events. They 
also occur across a range of environmental gradients, indicating the 
retention of adaptive capacity (i.e., representation). Populations also 
occur in Mexico and there is suitable habitat present in basins where 
it has been found. Thus, after assessing the best available 
information, we conclude that the Rio Grande sucker is not in danger of 
extinction throughout all of its range (i.e., endangered).
    We then assessed whether extirpation risk as well as resiliency, 
redundancy, and representation would change over time. To inform future 
resiliency, we modelled future changes in habitat suitability under two 
future RCP scenarios: RCP4.5 and RCP8.5. Then we incorporated these 
changes in our estimation of future risk of extirpation for each 
population. Although the general trend was a decrease in habitat 
suitability over time, most populations (69 percent) are projected to 
have no changes in resiliency. Similar patterns of habitat change were 
projected for portions of the range in Mexico. Although changes in 
redundancy and representation are anticipated should high risk 
populations be extirpated, the low and moderate risk populations will 
continue to be distributed across the species range, conferring 
redundancy and representation. After assessing the best available 
information, we conclude that the species is not likely to become 
endangered within the foreseeable future throughout all of its range.
    We also evaluated whether the Rio Grande sucker is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Rio Grande sucker's range for which both (1) the 
portion is significant, and (2) the species is in danger of extinction 
in that portion, either now or within the foreseeable future. Thus, 
after assessing the best available information, we conclude that the 
Rio Grande sucker is not in danger of extinction in a significant 
portion of its range now, or within the foreseeable future.
    After assessing the best available information, we concluded that 
the Rio Grande sucker is not in danger of extinction or likely to 
become in danger of extinction throughout all of its range or in any 
significant portion of its range. Therefore, we find that listing the 
Rio Grande sucker as an endangered species or threatened species under 
the Act is not warranted. A detailed discussion of the basis for this 
finding can be found in the Rio Grande sucker species assessment form 
and other supporting documents on https://www.regulations.gov under 
Docket No. FWS-R2-ES-2024-0082 (see ADDRESSES, above).
Peer Review
    In accordance with our July 1, 1994, peer review policy (59 FR 
34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo 
on the Peer Review Process we solicited independent scientific reviews 
of the information contained in the Rio Grande sucker SSA report. The 
Service 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 under Docket No. FWS-R2-ES-
2024-0082. We incorporated the results of these reviews, as 
appropriate, into the SSA Report, which is the foundation for this 
finding.

New Information

    We request that you submit any new information concerning the 
taxonomy of, biology of, ecology of, status of, or stressors to the 
Kiamichi crayfish, Rio Grande chub, or Rio Grande sucker to the 
appropriate person, as specified under FOR FURTHER INFORMATION CONTACT, 
whenever it becomes available. New information will help us monitor 
these species and make appropriate decisions about their conservation 
and status. We encourage local agencies and stakeholders to continue 
cooperative monitoring and conservation efforts.

References

    A complete list of the references used in these petition findings 
is available in the relevant species assessment form, which is 
available on the internet at https://www.regulations.gov in the 
appropriate docket (see ADDRESSES, above) and upon request from the 
appropriate person (see FOR FURTHER INFORMATION CONTACT, above).

[[Page 51869]]

Authors

    The primary authors of this document are the staff members of the 
Species Assessment Team, Ecological Services Program.

Authority

    The authority for this action is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2024-13617 Filed 6-18-24; 8:45 am]
BILLING CODE 4333-15-P