[Federal Register Volume 88, Number 228 (Wednesday, November 29, 2023)]
[Proposed Rules]
[Pages 83368-83377]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-25586]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FF09E21000 FXES1111090FEDR245]


Endangered and Threatened Wildlife and Plants; Seven 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 seven 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 Edison's ascyrum (Hypericum edisonianum), Florida 
(lowland) loosestrife (Lythrum flagellare), Florida pinesnake 
(Pituophis melanoleucus mugitu), mimic cavesnail (Phreatodrobia 
imitata), northern cavefish (Amblyopsis spelaea), smallscale darter 
(Etheostoma microlepidum), and Texas troglobitic water slater 
(Lirceolus smithii). 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 November 29, 2023.

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

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             Species                             Docket No.
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Edison's ascyrum.................  FWS-R4-ES-2023-0172
Florida (lowland) loosestrife....  FWS-R4-ES-2023-0173
Florida pinesnake................  FWS-R4-ES-2023-0174
Mimic cavesnail..................  FWS-R2-ES-2023-0175
Northern cavefish................  FWS-R4-ES-2023-0176
Smallscale darter................  FWS-R4-ES-2023-0177
Texas troglobitic water slater...  FWS-R2-ES-2023-0178
------------------------------------------------------------------------

    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: 

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           Species                        Contact information
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Edison's ascyrum, Florida      Lourdes Mena, Division Manager, Florida
 (lowland) loosestrife, and     Ecological Services Field Office,
 Florida pinesnake.             <a href="/cdn-cgi/l/email-protection#8fe3e0fafdebeafcd0e2eae1eecfe9f8fca1e8e0f9"><span class="__cf_email__" data-cfemail="d7bbb8a2a5b3b2a488bab2b9b697b1a0a4f9b0b8a1">[email protected]</span></a>, 904-460-4970.
Mimic cavesnail and Texas      Karen Myers, Field Supervisor, Austin
 troglobitic water slater.      Ecological Services Field Office,
                                <a href="/cdn-cgi/l/email-protection#610a0013040f3e0c18041312210716124f060e17"><span class="__cf_email__" data-cfemail="abc0cad9cec5f4c6d2ced9d8ebcddcd885ccc4dd">[email protected]</span></a>, 512-937-7371.
Northern cavefish............  Lee Andrews, Field Supervisor, Kentucky
                                Ecological Services Field Office,
                                <a href="/cdn-cgi/l/email-protection#076b626258666963756270744761707429606871"><span class="__cf_email__" data-cfemail="1f737a7a407e717b6d7a686c5f79686c31787069">[email protected]</span></a>, 502-695-0468 ext.
                                46108.
Smallscale darter............  Dan Elbert, Field Supervisor, Tennessee
                                Ecological Services Field Office,
                                <a href="/cdn-cgi/l/email-protection#adc9ccc3c4c8c1f2c8c1cfc8dfd9edcbdade83cac2db"><span class="__cf_email__" data-cfemail="4226232c2b272e1d272e20273036022435316c252d34">[email protected]</span></a>, 931-525-4973.
------------------------------------------------------------------------

    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

[[Page 83369]]

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 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. The term 
``foreseeable future'' extends only so far into the future as the 
Service can reasonably determine that both the future threats and the 
species' responses to those threats are likely. In other words, the 
foreseeable future is the period of time in which we can make reliable 
predictions. ``Reliable'' does not mean ``certain''; it means 
sufficient to provide a reasonable degree of confidence in the 
prediction. Thus, a prediction is reliable if it is reasonable to 
depend on it when making decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.
    In conducting our evaluation of the five factors provided in 
section 4(a)(1) of the Act to determine whether the Edison's ascyrum, 
Florida (lowland) loosestrife, Florida pinesnake, mimic cavesnail, 
northern cavefish, smallscale darter, or Texas troglobitic water slater 
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 
seven 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 seven actions included in 
this document. The following is a description of the documents 
containing these analyses:
    The species assessment forms for the Edison's ascyrum, Florida 
(lowland) loosestrife, Florida pinesnake, mimic cavesnail, northern 
cavefish, smallscale darter, and Texas troglobitic water slater 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 seven 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).

Edison's Ascyrum

Previous Federal Actions
    On April 20, 2010, we received a petition from the Center for 
Biological Diversity, Alabama Rivers Alliance, Clinch Coalition, 
Dogwood Alliance, Gulf Restoration Network, Tennessee Forests Council, 
and West Virginia Highlands to list 404 aquatic, riparian, and wetland 
species, including Edison's ascyrum, as endangered or threatened 
species under the Act. On September 27, 2011, we published in the 
Federal Register (76 FR 59836) a 90-day finding that the petition 
contained substantial information indicating that listing may be 
warranted for Edison's ascyrum. This document constitutes our 12-month 
finding on the 2010 petition to list Edison's ascryum under the Act.
Summary of Finding
    Edison's ascyrum is a small colonial shrub in the St. John's wort 
family (Hypericaceae) that can grow to 1.5 meters (m) (5 feet (ft)) 
tall. The species occurs most abundantly in seasonal ponds (i.e., 
depression marshes), but

[[Page 83370]]

also inhabits flatwoods, wet prairies, cutthroat grass seeps, lake 
margins, and occasionally roadsides and semi-native pastures. Edison's 
ascyrum is confined mostly to the southern Lake Wales Ridge in central 
peninsular Florida. The Lake Wales Ridge is a 186-kilometer (km) (116-
mile (mi)) long, major geomorphological feature stretching from just 
south of Lake Harris in Lake County to near the Highlands/Glades County 
line. The species was historically known from only Highlands and Glades 
Counties, and it currently occurs in abundance in these two counties. 
Additional vouchered counties include DeSoto, Polk, and Collier.
    Edison's ascyrum can flower year-round but usually reproduces via 
clonal propagation. Genets (genetically distinct individuals) are 
usually composed of several ramets that sprout from underground 
rhizomes. Edison's ascyrum is able to rapidly regenerate ramets 
following disturbances such as fire and prolonged inundation, which 
likely enhances both genet fitness and persistence.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Edison's ascyrum, and we evaluated all relevant factors under 
the five listing factors, including any regulatory mechanisms and 
conservation measures addressing these threats. The primary threats 
identified for Edison's ascyrum's biological status include habitat 
loss and degradation, changes in fire patterns, and hydrological 
changes. Habitat loss and degradation are expected to be driven by 
development, which, along with climate change, will potentially cause 
hydrological changes. However, approximately 77 percent of the known 
occurrences are on conservation lands, which are managed in ways that 
benefit the species and its habitat. Since recent estimates of 
population size were not available for most features, we used a 
habitat-based approach to assess the resiliency of each analysis unit. 
Specifically, we considered four factors: area of available habitat, 
percentage of incompatible land use, habitat protection, and habitat 
management. Thirteen of the 22 analysis units (AUs) identified 
throughout the species' range have moderate to high resiliency. Through 
this resiliency assessment, we found that AUs that exhibit a moderate 
or high rank for habitat management are distributed throughout the 
range. There is some risk from development, altered hydrology, and 
altered fire patterns due to the localized nature of this species' 
range, but the species is thriving in several areas under long-term 
protection and management. Although the species has a narrow range, 
four of the AUs of high-moderate to high resiliency are distributed 
from north to south across Avon Park Air Force Range, Archbold 
Biological Station, and Fisheating Creek Wildlife Management Area. 
Thus, after assessing the best available information, we conclude that 
the Edison's ascyrum is not in danger of extinction throughout all of 
its range.
    We then considered whether the species is likely to become in 
danger of extinction within the foreseeable future throughout its 
range. Habitat loss and degradation, fire exclusion, and hydrological 
changes are the biggest threats to the species in the future. Habitat 
loss and degradation in the future is expected to be driven by 
population growth and development in the species' habitat, as well as 
hydrological changes due to development and climate change. We 
evaluated the future condition of the species under two future 
scenarios at two timesteps (2040 and 2070). In the future, resiliency 
is projected to vary between AUs, but the species is projected to be 
represented by moderate to high resiliency populations throughout its 
range. The distribution of moderate to high resiliency populations 
across the range on protected lands may minimize the likelihood of a 
catastrophic event affecting the species rangewide. Additionally, under 
both scenarios and for both timesteps, AUs not expected to decrease in 
resiliency remain spread across the range of the species. Under 
scenario 1, resiliency is projected to decrease in 8 AUs by 2040, and 
12 AUs by 2070. Under scenario 2, under both timesteps, resiliency is 
projected to decrease in 5 AUs. Overall, the species will remain 
represented across the range. In addition, 77 percent of the known 
occurrences are on conservation lands. Thus, after assessing the best 
available information, we conclude that Edison's ascyrum is not in 
danger of extinction throughout all of its range now, or within the 
foreseeable future.
    We also evaluated whether the Edison's ascyrum is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Edison's ascyrum'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 Edison's 
ascyrum 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 
Edison's ascyrum is not in danger of extinction or likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range or in any significant portion of its range. Therefore, we 
find that listing the Edison's ascyrum 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 Edison's 
ascyrum species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0172 (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 Edison's ascyrum SSA report. The 
Service sent the SSA report to eight independent peer reviewers and 
received two responses. Results of this structured peer review process 
can be found at https://www.regulations.gov. We incorporated the 
results of these reviews, as appropriate, into the SSA report, which is 
the foundation for this finding.

Florida (Lowland) Loosestrife

Previous Federal Actions
    On April 20, 2010, we received a petition from the Center for 
Biological Diversity, Alabama Rivers Alliance, Clinch Coalition, 
Dogwood Alliance, Gulf Restoration Network, Tennessee Forests Council, 
and West Virginia Highlands to list 404 aquatic, riparian, and wetland 
species, including lowland (Florida) loosestrife, as endangered or 
threatened species under the Act. On September 27, 2011, we published 
in the Federal Register (76 FR 59836) a 90-day finding that the 
petition contained substantial information indicating that listing may 
be warranted for Florida (lowland) loosestrife. This document 
constitutes our 12-month finding on the 2010 petition to list Florida 
loosestrife under the Act.
Summary of Finding
    Florida loosestrife is a perennial herb endemic to the subtropical 
zone of Florida, largely on the western side of the State. The species 
occurs in seasonally inundated open areas and can tolerate moderate 
levels of

[[Page 83371]]

disturbance. For example, it can be found in roadside ditches and 
disturbed wetlands along with swamps, marshes, and wet prairies. The 
species can be very abundant where it occurs, often numbering in the 
thousands, forming dense mats and dominating the groundcover. Both the 
historical and current distribution of Florida loosestrife is not fully 
known. Vouchered counties include Charlotte, Collier, DeSoto, Glades, 
Hardee, Hendry, Hernando, Hillsborough, Lee, Manatee, Okeechobee, 
Orange, and Sarasota. However, the species has also been documented in 
Broward and Citrus Counties and reported in Palm Beach County.
    Little is known about the life history of Florida loosestrife. It 
is reported that it flowers year-round, but it likely most reliably 
flowers in spring. Plants that experience seasonal flooding beginning 
in late spring to early summer must flower and set seed before they are 
inundated. Florida loosestrife seeds likely disperse within floodplains 
via sheet flow. Pollinators are not known.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Florida loosestrife, and we evaluated all relevant factors under 
the five factors, including any regulatory mechanisms and conservation 
measures addressing these threats. The primary threats identified for 
Florida loosestrife include direct and indirect impacts of development 
and sea level rise (SLR). The species' range is moderately restricted, 
occurring in 12 counties and 35 watersheds, with many of the records 
occurring in the last few years as efforts to locate the species have 
increased.
    Current threats to the species are largely related to habitat 
conversion associated with urbanization and other development (e.g., 
agriculture); however, the species continues to occur in urbanized and 
other developed areas, albeit in highly altered habitats. The species' 
ability to survive in different settings is reflected in the species' 
resiliency; as documented in the SSA report, 22 of the 35 units have at 
least moderate resiliency. Given the apparent resiliency of the plants 
in developed areas, the high number of units with moderate to very high 
resiliency, and the species' ability to adapt to disturbed 
environments, the species is not in danger of extinction throughout all 
of its range.
    Next, we considered whether the Florida loosestrife is likely to 
become endangered within the foreseeable future throughout all of its 
range. For the Florida loosestrife, habitat loss and degradation (from 
urban and agricultural development) and SLR are projected to be the 
biggest threats to the species in the future. To evaluate the future 
condition of the species, we developed two plausible future scenarios 
to project the outcomes of future urban and agricultural development 
and SLR at two timesteps (2040 and 2070). However, even under higher 
projected development and SLR scenarios, the species is expected to 
have sufficient redundancy with several moderate to high resiliency 
populations distributed across the range of the species. We, therefore, 
determined that the scale of impacts projected in the future will not 
affect the species such that it is likely to become an endangered 
species in the foreseeable future. Thus, after assessing the best 
available information, we conclude that Florida loosestrife is not in 
danger of extinction now, or within the foreseeable future throughout 
all of its range.
    We also evaluated whether the Florida loosestrife is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Florida loosestrife'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 
Florida loosestrife 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 
Florida loosestrife is not in danger of extinction or likely to become 
in danger of extinction within the foreseeable future throughout all of 
its range or in any significant portion of its range. Therefore, we 
find that listing the Florida loosestrife 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 Florida 
loosestrife species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0173 (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 Florida loosestrife SSA report. The 
Service sent the SSA report to six independent peer reviewers and 
received two responses. Results of this structured peer review process 
can be found at https://www.regulations.gov. We incorporated the 
results of these reviews, as appropriate, into the SSA report, which is 
the foundation for this finding.

Florida Pinesnake

Previous Federal Actions
    On July 11, 2012, the Service was petitioned by the Center for 
Biological Diversity, Thomas Lovejoy, Kenney Krysko, C. Kenneth Dodd, 
Jr., Allen Salzberg, Edward O. Wilson, and Michael J. Lannoo to list 53 
amphibians and reptiles in the United States, including the Florida 
pinesnake, as endangered or threatened species under the Act. In 
response to the petition, on September 18, 2015, the Service published 
in the Federal Register (80 FR 56423) a 90-day finding that the 
petition contained substantial information indicating the Florida 
pinesnake may warrant listing. This document constitutes our 12-month 
finding on the 2012 petition to list the Florida pinesnake under the 
Act.
Summary of Finding
    The Florida pinesnake is a large, non-venomous, diurnal, and highly 
fossorial constrictor endemic to the Coastal Plains of the southeastern 
United States. Its recognized range spans from southeastern South 
Carolina, through central and south Georgia, to south Florida and west 
into the Florida panhandle and the southern part of Alabama. This 
subspecies exhibits a strong preference for pine forests with open-
canopy, well-drained, sandy soil, and frequent fires. Five main habitat 
elements that appear to be essential to the survival and reproductive 
success of individuals are well-drained soils, suitable vegetation 
structure and composition, low nearby road density, an appropriate fire 
return interval, and presence of prey. Pinesnakes are active foragers 
that hunt a variety of prey both above and below ground. As 
accomplished burrowers, they can tunnel through loose soil, dig nests, 
and excavate rodents for food. They also use existing underground 
burrows and tunnels created by other species, such as the southeastern 
pocket gopher (Geomys pinetis), for refugia.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Florida pinesnake, and we evaluated all relevant factors under 
the five listing factors, including any regulatory mechanisms and 
conservation measures addressing these threats. Florida

[[Page 83372]]

pinesnakes are associated with various actions that are associated with 
the loss and degradation of habitat. Habitat loss is due to a number of 
factors, including fire suppression, historical and incompatible 
silvicultural practices, SLR, conversion of land to agriculture, and 
urbanization. The current constraints on the ability to manage pine 
habitat through prescribed fire may be exacerbated by urbanization and 
climate change in the future. It is possible that several of these 
factors are acting synergistically to impact the Florida pinesnake.
    Although there is still uncertainty surrounding the evaluated 
stressors and their synergistic effects, habitat loss and modification, 
due to the effects of both urban development and climate change, were 
considered in the assessment of Florida pinesnake populations and the 
subspecies' overall viability. Currently, across the subspecies' range, 
there are no documented impacts at the population level from invasive 
species, persecution or increased harassment, overcollection for the 
pet trade, or disease. While habitat loss and modification are the 
primary factor influencing the subspecies, many Florida pinesnake 
populations have moderate to high resiliency in the face of these 
threats.
    It is estimated that Florida pinesnakes have likely lost 30.8 
percent (41 of 133 populations) of their historical populations due to 
loss and degradation of habitat, representing 9 percent of the total 
occupied range of the subspecies. The remaining 69.2 percent of the 
populations, covering 90.4 percent of the total historical range, have 
a greater than 50 percent probability of persisting, and are considered 
extant as of 2021. Of the extant populations, 71.2 percent of 
populations (66 populations) covering 93.2 percent of the current 
occupied range are very likely or extremely likely to persist as of 
2021, and they have moderate to high resiliency. Thirty-one and half 
percent of populations covering 77.1 percent of the current occupied 
range are considered to have high resiliency. We estimate that all 
seven representative units have likely lost at least one historic, 
delineated population. Despite this decrease from the historical number 
of populations, all representative units have multiple populations, 
which meets our criteria for high redundancy. Because two 
representative units do not have populations in the highest persistence 
category, and those units are on the northern and western portions of 
the subspecies range, we consider the current representation to be 
moderate. We, therefore, conclude that the Florida pinesnake is not in 
danger of extinction throughout all of its range.
    In considering the foreseeable future as it relates to the status 
of the Florida pinesnake, we considered the relevant risk factors 
(i.e., threats/stressors) affecting the subspecies and whether we could 
draw reliable predictions about the subspecies' response to these 
factors. We considered whether we could reliably assess the risk posed 
by the threats to the subspecies, recognizing that our ability to 
assess risk is limited by the variable quantity and quality of 
available data about effects to the Florida pinesnake and its response 
to those threats.
    In the future, land-use change and other anthropogenic activities 
may impact Florida pinesnake habitat through loss of habitat and 
fragmentation. Our analysis of two future scenarios until 2080 
encompasses the best available information for future projections of 
levels of urbanization, and it uses two different representative 
concentration pathways (RCPs) for climate change (i.e., A1B and B2) to 
look at the effects of SLR and prescribed burn windows. We determined 
that that timeframe enables us to consider the threats/stressors acting 
on the subspecies and to draw reliable predictions about the 
subspecies' response to these threats/stressors.
    Loss of habitat and fragmentation threats associated with 
urbanization and climate change are projected to occur throughout the 
subspecies' range. The importance of protected lands and managing 
habitats through burning will continue to play an important role for 
this subspecies. Given the future scenarios, the resiliency of Florida 
pinesnake populations are projected to decline in the future. Under 
both scenarios, in 2040, 30 populations are projected to have moderate 
or high resiliency, covering 73 percent of the occupied range. Under 
both scenarios, at 2080, 11 populations are projected to have moderate 
or high resiliency, covering 62 percent of the occupied range. 
Subspecies' representation and redundancy are projected to decrease 
from moderate and high, respectively, in current condition levels to 
moderate in the future. The number of representative units with 
populations in moderate and high resiliency are projected to decrease 
under all scenarios and timesteps. However, the subspecies is projected 
to maintain broad occurrence across its range even under the projected 
future threats, with five of seven representation units containing 
populations of moderate or high resiliency into the future. Although 
the total number of populations is projected to decline by 2080, 62 
percent of the current range of the Florida pinesnake remains occupied 
by multiple populations with greater than 80 percent probability of 
persistence (moderate and high resiliency); therefore, the subspecies 
is projected to have moderate redundancy, providing the subspecies the 
ability to withstand catastrophic events. These populations cover a 
large geographic area and maintain high or moderate resiliency due to 
adequate suitable habitat coverage, high proportion of area within 
protected areas, sufficient connectivity, and low impact of threats in 
the future. Thus, after assessing the best available information, we 
determine that the Florida pinesnake is not in danger of extinction now 
or likely to become so within the foreseeable future throughout all of 
its range.
    We also evaluated whether the Florida pinesnake is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the Florida pinesnake'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 in the future. Thus, after assessing the 
best available information, we conclude that the Florida pinesnake 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 Florida pinesnake is not in danger of extinction or likely to 
become in danger of extinction within the foreseeable future throughout 
all of its range or in any significant portion of its range. Therefore, 
we find that listing the Florida pinesnake 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 Florida 
pinesnake species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0174 (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 Florida pinesnake SSA report. The 
Service sent the SSA report to seven independent peer reviewers and 
received six responses. Results of this structured peer review process 
can be found at https://www.regulations.gov. We incorporated the 
results of these

[[Page 83373]]

reviews, as appropriate, into the SSA report, which is the foundation 
for this finding.

Mimic Cavesnail

Previous Federal Actions
    On June 25, 2007, the Service received a petition from Forest 
Guardians (i.e., WildEarth Guardians) requesting that the Service list 
475 species, including the mimic cavesnail, as endangered or threatened 
species and designate critical habitat under the Act. All 475 species 
occur within the Southwestern Region and were ranked as G1 or G1G2 
species by NatureServe at the time. On December 16, 2009, the Service 
published in the Federal Register (74 FR 66866) a partial 90[hyphen]day 
finding on the mimic cavesnail and 191 other species, stating that the 
petition presented substantial scientific information indicating that 
listing may be warranted for 67 of the 192 species, including the mimic 
cavesnail. This document constitutes our 12-month finding on the 2007 
petition to list the mimic cavesnail under the Act.
Summary of Finding
    The mimic cavesnail is a freshwater snail endemic to a deep portion 
of the karstic Edwards Aquifer in Bexar County, Texas. It is a very 
small snail, with average shell height of about 1.0 millimeter (mm) 
(0.04 inch (in)), a thin operculum, and trapezoidal radula. Freshwater 
gastropods are broadly characterized by rapid growth and short 
lifespans, which result in high reproduction rates and short rates of 
population turnover. Species may reproduce a single or multiple 
generations per year.
    The range of the mimic cavesnail is situated at the southwestern 
extent of the San Antonio-New Braunfels metropolitan area in Bexar 
County, Texas. The distribution of the mimic cavesnail is dependent 
upon the availability and connectivity of suitable aquatic subterranean 
habitat; this habitat has sufficient water quality and quantity within 
deep karstian spaces. Prior to 1986, the mimic cavesnail was known from 
only two groundwater wells, O.R. Mitchell (State Well Number 6843601) 
and Verstraeten Wells (State Well Number 6843607). In 2021, the species 
was discovered at Aldridge 209 Well (State Well Number 6843802), which 
is 5 km (3 mi) to the southwest of O.R. Mitchell and Verstraeten Wells. 
All mimic cavesnail wells occur just to the northwest of the 
freshwater/saline-water interface.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the mimic cavesnail, 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 mimic cavesnail's biological status include mortality 
from groundwater wells, reductions in groundwater quantity (including 
reductions via climate change), and groundwater contamination.
    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we found that well mortality, groundwater quantity, and 
groundwater contamination are not currently affecting the mimic 
cavesnail at the population level. Direct mortality through expulsion 
from groundwater wells is occurring, but the species' benthic 
lifestyle, high reproductive rate, and short lifespan result in this 
mortality being unlikely to affect the population's resiliency. In 
addition, two of the three wells that ejected mimic cavesnails are 
inactive, which removes those as sources of mortality for the species. 
Because it is a benthic species, it is less susceptible to entrainment 
and expulsion from wells, and species with life-history traits like the 
mimic cavesnail's are unlikely to be affected by the mortality observed 
at the groundwater wells where it has been found. Further, groundwater 
quantity at the depths where mimic cavesnail occurs has not been 
affected by groundwater withdrawals, and we have no information 
indicating that will change in the future. Finally, we have no evidence 
of groundwater contamination at these depths. Thus, we conclude that 
the mimic cavesnail is not in danger of extinction throughout all of 
its range.
    To assess the future conditions of the mimic cavesnail, we 
evaluated climate change and land-use projections under only the most 
plausible future scenario from 2022 to 2100. No new wells have been 
drilled in the immediate area analysis unit since 1995. We assume that 
this trend will continue and be accompanied by an increase in the 
capping or plugging of older groundwater wells. We expect that well 
mortality will decline through 2100.
    In the future, the area surrounding mimic cavesnail habitat is 
projected to have increased human population growth and exurban and 
suburban development; increased demands for water; and a warming, more 
drought-prone climate. Climate change will also impact the area, with 
increasing average and extreme temperatures, but no substantial change 
in precipitation is expected.With little change in rainfall and 
increased temperatures, evapotranspiration could increase reducing 
surface run-off and ultimately aquifer recharge. During drought years, 
recharge could be reduced by 21-33 percent, and flows at Comal Springs 
could decrease by 10-24 percent, which would initiate groundwater 
withdrawal reductions under current State and local regulations. We 
project that climate change will result in less groundwater extraction 
from the Edwards Aquifer given existing regulations to protect species 
listed under the Act in the Comal and San Marcos Springs Systems, as 
well as limit water withdrawals from the Edwards Aquifer. We would also 
expect less dependence on groundwater in the future due to ongoing and 
planned efforts to conserve and augment water resources in the San 
Antonio-New Braunfels metropolitan area. Given this and historically 
small declines in water levels, we expect that aquifer levels would not 
decline and cavesnail habitat would be maintained.
    The potential for groundwater contamination in the San Antonio 
segment will continue into the future. New contaminant sources are 
expected to be added to the region with increased human populations and 
expanded development; many existing contaminant sources will persist. 
There is an ongoing effort by the City of San Antonio to protect 
sensitive areas of the contributing and recharge zones in Bexar, 
Medina, and Uvalde Counties. Existing protected lands will potentially 
aid in reducing transport of contaminants to the San Antonio segment. 
The mimic cavesnail is also somewhat buffered from the immediate 
effects of contaminants at least in the near-term future. Deeper 
portions of that aquifer segment have historically been less impacted 
by contaminants, but that could change over several decades with 
increasing urbanization. Furthermore, the San Antonio segment has a 
great capacity to assimilate and dilute contaminants due to the massive 
volumes of water transported through the aquifer. The best available 
information does not allow us to determine whether contaminants would 
ever reach concentrations that would impair mimic cavesnail habitat. 
Thus, after assessing the best available information, we conclude that 
the mimic cavesnail is not likely to become endangered within the 
foreseeable future throughout all of its range.
    We also evaluated whether the mimic cavesnail is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the mimic

[[Page 83374]]

cavesnail'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 in the foreseeable future. Thus, after assessing the best available 
information, we conclude that the mimic cavesnail 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 
mimic cavesnail is not in danger of extinction or likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range or in any significant portion of its range. Therefore, we 
find that listing the mimic cavesnail 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 mimic 
cavesnail species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R2-ES-2023-0175 (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 mimic cavesnail SSA report. The 
Service sent the SSA report to five independent peer reviewers and 
received two responses. Results of this structured peer review process 
can be found at https://www.regulations.gov. We incorporated the 
results of these reviews, as appropriate, into the SSA report, which is 
the foundation for this finding.

Northern Cavefish

Previous Federal Actions
    On April 20, 2010, we received a petition from the Center for 
Biological Diversity, Alabama Rivers Alliance, Clinch Coalition, 
Dogwood Alliance, Gulf Restoration Network, Tennessee Forests Council, 
and West Virginia Highlands Conservancy to list 404 aquatic, riparian, 
and wetland species, including the northern cavefish, as endangered or 
threatened species under the Act. On September 27, 2011, we published 
in the Federal Register (76 FR 59836) a 90-day finding that the 
petition contained substantial information indicating listing may be 
warranted for the northern cavefish. This document constitutes our 12-
month finding on the 2010 petition to list the northern cavefish under 
the Act.
Summary of Finding
    Native to central Kentucky, the northern cavefish is a small, cave-
dwelling fish found only in subterranean drainages. It is characterized 
by its rudimentary eyes; lack of skin pigment; large, flat head; and 
tubular, non-streamlined body. The standard length (tip of nose to end 
of last vertebra) of adult northern cavefish ranges from approximately 
60 to 80 mm (2.4 to 3.1 in). The maximum known age for northern 
cavefish is 10 years, but the lifespan may be 20 to 40 years. The 
species has four life stages: egg, protolarva, juvenile, and adult. 
Eggs and protolarvae are held in the female's gill chamber until 
reaching the juvenile stage, when they swim freely apart from the 
mother. Age at reproductive maturity (adulthood) is around 6 years.
    Northern cavefish occur in subterranean streams in Meade, 
Breckinridge, Hardin, Hart, and Edmonson Counties, Kentucky, south of 
the Ohio River. In Kentucky, this area is characterized as a karst 
ecosystem with underground drainage systems comprised of sinkholes and 
caves. The closely related Hoosier cavefish (Amblyopsis hoosieri) is 
restricted to Indiana north of the Ohio River. Formerly, the Hoosier 
cavefish was recognized as the northern cavefish, but the Hoosier 
cavefish is now known to be a distinct taxon based on morphological and 
genetic differences. Because northern cavefish inhabit underground 
stream networks that cannot be mapped or surveyed, the species likely 
occurs at sites that are inaccessible, and the true distribution and 
number of populations within the range of the northern cavefish is 
unknown.
    Individuals of all northern cavefish life stages need generally 
cool water temperatures, sufficient dissolved oxygen, low salinity, and 
flowing water. The species needs slow-flowing pools or shoals, a food 
supply of invertebrates (may occasionally consume other northern 
cavefish), and substrates composed of fine particles. Floods are 
important for juveniles and adults as they provide detritus and food 
resources. At the population level, floods are important for 
reproduction (renewing generations) and maintaining connectivity, 
likely allowing passive transport between sites.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the northern cavefish, 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 northern cavefish's biological status include water 
pollution, agriculture and forest loss, municipal and industrial 
development, and impoundment of surface waters.
    Historically, there were at least six metapopulations (single 
population with subpopulations at different sites and some connectivity 
between sites) of northern cavefish. Two of those populations have no 
records since the 1990s and cannot be confirmed to be extant or 
extirpated. Based on occurrence records since 2000, the other four 
northern cavefish metapopulations are known to remain extant in two 
representation units. The representation units are separated by the 
Rough Creek Fault Zone, which is likely a barrier to cavefish 
dispersal. Population resiliency was not directly assessed; however, 
the number of individuals encountered during surveys of most sites is 
20 or fewer, but some sites (subpopulations) have documented hundreds 
of northern cavefish.
    Northern cavefish may be negatively impacted by groundwater 
contamination via storm runoff or intentional disposal of wastes in 
sinkholes, which are a predominant landscape feature in the species' 
range. While there is risk of a spill or surface release of 
contaminants to groundwater, there have been no documented cases of 
northern cavefish being harmed by such an event. In addition, it is 
unlikely contamination events would affect all populations, as the two 
representation units are separated by a fault zone barrier. Further, 
there is redundancy of subpopulations within at least two of the four 
known extant metapopulations (at least one metapopulation in each 
representation unit has multiple populations). Because there is 
redundancy of subpopulations within three of the four known, extant 
metapopulations (at least one metapopulation in each representation 
unit has multiple subpopulations) there are multiple populations 
distributed across a wide area (which buffers the impacts of adverse 
events), the current risk of extinction is low. Therefore, we find that 
the species is not in danger of extinction throughout all of its range.
    Our future conditions analysis for the northern cavefish used 
projections of land uses and climate to assess potential groundwater 
contamination and changes in stream discharge and water temperature, 
respectively, to 30- and 50-year time horizons. It is reasonable to 
rely on these time horizons because they correspond to the range of 
available urbanization and land use change model forecasts. 
Furthermore, approximately

[[Page 83375]]

30 and 50 years represent timeframes for the species to respond to 
potential changes on the landscape. Two scenarios were projected, one 
under which human population growth and economic development is slow, 
and another under which such growth and development is more rapid. 
Climate in the species' range is expected to be warmer and wetter, but 
is unlikely to be a major threat to the species at the time horizons 
considered in our analysis. Likewise, under both scenarios and time 
horizons, the portion of developed land is expected to change very 
little. Given the projected small changes in threats and land use to 
2070, we expect the northern cavefish will maintain species' redundancy 
and representation similar to current levels. In addition, the best 
scientific information indicates the species' population conditions 
have not substantially changed over time and are not expected to change 
within the foreseeable future given the projected lack of change in 
land uses and threats. Thus, after assessing the best available 
information, we conclude that the northern cavefish is not likely to 
become an endangered species within the foreseeable future throughout 
all of its range.
    We also evaluated whether the northern cavefish is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the northern cavefish'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 
northern cavefish 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 
northern cavefish is not in danger of extinction or likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range or in any significant portion of its range. Therefore, we 
find that listing the northern cavefish 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 northern 
cavefish species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0176 (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 northern cavefish SSA report. The 
Service sent the SSA report to seven independent peer reviewers and 
received no responses. Although we received no peer review responses, 
we received input from species experts during development of the SSA, 
which is incorporated into and cited in the SSA report. Results of this 
structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as 
appropriate, into the SSA report, which is the foundation for this 
finding.

Smallscale Darter

Previous Federal Actions
    On April 20, 2010, we received a petition from the Center for 
Biological Diversity, Alabama Rivers Alliance, Clinch Coalition, 
Dogwood Alliance, Gulf Restoration Network, Tennessee Forests Council, 
and West Virginia Highlands to list 404 aquatic, riparian, and wetland 
species, including the smallscale darter, as endangered or threatened 
species under the Act. On September 27, 2011, we published in the 
Federal Register (76 FR 59836) a 90-day finding that the petition 
contained substantial information indicating listing may be warranted 
for the smallscale darter. This document constitutes our 12-month 
finding on the 2010 petition to list the smallscale darter under the 
Act.
Summary of Finding
    The smallscale darter is a member of the Class Actinopterygii (ray-
finned fishes), Order Perciformes, Family Percidae (perches), in the 
subfamily Etheostomatinae (darters). This midsized darter reaches a 
maximum length of 93 mm (3.6 in). The species is native to the Stones 
River, Harpeth River, Red River, and Little River tributaries of the 
Cumberland River System in Kentucky and Tennessee. The Harpeth River 
and Stones River populations are in the greater Nashville area of 
Tennessee, while the Little River population is in Kentucky. The Red 
River population straddles the border of Kentucky and Tennessee. The 
smallscale darter is extant throughout its historical range.
    Stream reaches occupied by smallscale darters tend to have stable 
banks, intact riparian areas, and clean cobble and boulder substrate. 
These stream characteristics support the reproduction of smallscale 
darters, in which females attach eggs under a rock, and males protect 
the eggs until they hatch. Juveniles may inhabit areas where the 
current is slower, water is shallower, and substrate is finer than 
areas inhabited by adults. At the microhabitat level, smallscale 
darters use deeper and faster flowing parts of riffles than other 
darters in the species' range.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the smallscale darter, 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 smallscale darter's biological status include habitat 
destruction and degradation resulting from urbanization, agricultural 
land use, impoundments, and impaired water quality. We concluded in our 
analyses that impacts of isolated populations and climate change are 
not likely to negatively influence the species' viability. The 
smallscale darter is present throughout its historical range in four 
populations exhibiting moderate to moderate-high resiliency. This 
moderate to moderate-high resiliency of smallscale darter populations, 
combined with the species' presence throughout its historical area, 
provides moderate redundancy and representation rangewide. Given the 
moderate to moderate-high resiliency populations distributed across the 
historical range, the species is not currently in danger of extinction 
throughout its range. Thus, we find that the species is not in danger 
of extinction throughout all of its range.
    The smallscale darter is expected to maintain at least moderate 
resiliency across its range for the foreseeable future in all but one 
scenario for one population. For the smallscale darter, we identified 
the foreseeable future as 30 years, the time period for which we could 
reliably predict both relevant land cover change and the species' 
response to these changes. In all three future scenarios, we project 
the species to be extant in the entirety of its known range, with 
moderate resiliency for all populations in two of the three scenarios. 
We determined that the magnitude and scale of impacts projected in the 
future will not impact the species such that it is likely to become an 
endangered species within the foreseeable future. Thus, after assessing 
the best available information, we conclude that the smallscale darter 
is not likely to become an endangered species within the foreseeable 
future throughout all of its range.

[[Page 83376]]

    We also evaluated whether the smallscale darter is endangered or 
threatened in a significant portion of its range. We did not find any 
portions of the smallscale darter'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 
smallscale darter 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 
smallscale darter is not in danger of extinction or likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range or in any significant portion of its range. Therefore, we 
find that listing the smallscale darter 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 smallscale 
darter species assessment form and other supporting documents on 
https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0177 (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 smallscale darter SSA report. The 
Service sent the SSA report to five independent peer reviewers and 
received three responses. Results of this structured peer review 
process can be found at https://www.regulations.gov. We incorporated 
the results of these reviews, as appropriate, into the SSA report, 
which is the foundation for this finding.

Texas Troglobitic Water Slater

Previous Federal Actions
    On June 25, 2007, the Service received a petition from Forest 
Guardians (i.e., WildEarth Guardians) requesting that the Service list 
475 species, including the Texas troglobitic water slater, as 
endangered or threatened species and designate critical habitat under 
the Act. All 475 species occur within the Southwestern Region and were 
ranked as G1 or G1G2 species by NatureServe at the time. On December 
16, 2009, the Service published in the Federal Register (74 FR 66866) a 
partial 90[hyphen]day finding on the Texas troglobitic water slater and 
191 other species, stating that the petition presented substantial 
scientific information indicating that listing may be warranted for 67 
of the 192 species, including the Texas troglobitic water slater. This 
document constitutes our 12-month finding on the 2007 petition to list 
the Texas troglobitic water slater under the Act.
Summary of Finding
    The Texas troglobitic water slater is a small, aquatic subterranean 
crustacean located in the artesian zone of the southern segment (also 
referred to as the San Antonio segment) of the Edwards Aquifer in Hays 
County, Texas. Texas troglobitic water slaters are expelled from the 
artesian zone of the Edwards Aquifer through artesian wells and 
springs. Because of its primarily non-photosynthetic diet and high well 
mortality relative to other collected subterranean taxa (which may 
indicate a longer distance traveled to the surface), the Texas 
troglobitic water slater likely occupies depths somewhere between 60 m 
(197 ft) and 152 m (498 ft) below the surface. This species of water 
slater has been collected from three discharge sites: the San Marcos 
artesian well, Diversion Spring, and the training area well. These 
sites are all within 600 m (2,000 ft) of each other and in close 
proximity (less than approximately 100 m (330 ft)) to the freshwater/
saline-water zone of the Edwards Aquifer.
    The Texas troglobitic water slater lives in water-filled voids 
within the aquifer, although the species has never been directly 
observed in its natural subterranean habitat and, thus, its specific 
habitat preferences are not known. Observations of congeneric species 
indicate the capacity for high rates of reproduction and benthic 
(crawling) movement of the species. Stable isotope data suggest the 
Texas troglobitic water slater is relatively low on the food web, 
serving as a benthic forager and/or scraper. The primary type of food 
consumed by the Texas troglobitic water slater is produced at the 
freshwater/saline-water interface, which likely necessitates that the 
species lives within close proximity to this interface.
    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Texas troglobitic water slater, 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 Texas troglobitic water slater's 
biological status include reductions in water quantity through 
groundwater pumping and development, reductions in water quality, the 
effects of climate change, and mortality from groundwater wells.
    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we found that the best available information does not indicate 
direct negative effects from environmental or anthropogenic factors to 
the Texas troglobitic water slater population, nor is there evidence 
indicating a change to demographic factors from historical levels. The 
primary driving factors of Texas troglobitic water slater viability are 
water quantity (e.g., groundwater pumping and development) and water 
quality (e.g., development and impervious cover). The Texas troglobitic 
water slater has survived significant drought periods (including the 
drought of record from the late 1940s to mid-1950s) and despite the 
examined factors, the population has maintained resiliency for more 
than a century. Additionally, the best available information does not 
indicate that any groundwater contamination is affecting the species. 
Finally, direct mortality through expulsion from groundwater wells is 
occurring, but the species' benthic lifestyle and likely high 
reproductive rate result in this level of mortality being unlikely to 
affect the population's current resiliency.
    Our two plausible future scenarios for the species use projections 
out to 2050 and 2100. The primary factors driving the Texas troglobitic 
water slater population's future viability are water quantity and water 
quality. Increases in development lead to increases in impervious 
cover, altered recharge rates, and degraded water quality. The lands 
directly above Texas troglobitic water slater habitat are categorized 
as developed, and all anthropogenic factors already exist and will 
continue to influence the species' viability into the future. Projected 
land-use changes occurring over the recharge zone will also inhibit 
opportunities for surface water to enter the aquifer and for enough 
discharging water to effectively clear anthropogenic contaminants. 
Longer residence times of contaminants in groundwater and lack of 
photodegradation of constituents in the aquifer are not well 
understood, and it is uncertain how these changes will affect the Texas 
troglobitic water slater population into the future. There is no 
information assessing the environmental tolerance of the Texas 
troglobitic water slater or how degradation in water

[[Page 83377]]

quality can affect the species. Likewise, at this time, there are no 
appropriate isopod surrogates occupying a similar habitat with more 
information from which we could extrapolate for the Texas troglobitic 
water slater.
    While climate change and other anthropogenic influences (e.g., 
vegetation removal and urbanization) cause the surface to warm, a lag 
in increased groundwater temperature may occur. For ectothermic animals 
like the Texas troglobitic water slater, overall vulnerability to 
climate change will depend on thermal sensitivity and how quickly the 
buffered environment changes, and we do not have this information to 
inform our future scenarios. The southern segment of the Edwards 
Aquifer has a great capacity to assimilate and dilute contaminants as 
massive volumes of water transport these materials through the aquifer. 
However, contaminants in groundwater can be diluted over distance and 
time and flushed through discharge points more frequently than older 
groundwater at a greater depth. We have no information indicating 
whether contaminants would ever reach concentrations that would impair 
or kill Texas troglobitic water slaters in either scenario.
    Current water planning does not account for climate change, 
although climate change will be considered in the upcoming Edwards 
Aquifer Habitat Conservation Plan (HCP). There remains a possibility 
that current State and local regulations on groundwater use may not be 
enough to maintain aquifer levels and springflows if conditions become 
worse than the drought of record. The Edwards Aquifer Authority is 
committed to improving their HCP, and funding was allocated to predict 
droughts and climate change impacts on the aquifer. Land in Hays County 
over the recharge zone was purchased or protected through easements, 
and partners are committed to purchasing more land in the future, in 
addition to implementing other conservation efforts. If current 
management of the southern segment of the Edwards Aquifer continues 
into the future, aquifer levels should not decline to a level where 
Texas troglobitic water slater habitat would not be maintained.
    For both the lower and upper plausible future scenarios, the best 
available information does not project a negative impact from 
environmental or anthropogenic factors directly to the known Texas 
troglobitic water slater population at the depth at which they occur, 
nor is there evidence indicating a negative change to demographic 
factors historically. We expect that under both future scenarios, 
resiliency, redundancy, and representation of the species will be 
maintained into the foreseeable future. Neither future scenario 
projections point to evidence indicating any threat to the Texas 
troglobitic water slater population under current groundwater 
management implementation, which we anticipate will continue into the 
future. Thus, after assessing the best available information, we 
conclude that the Texas troglobitic water slater is not in danger of 
extinction or likely to become in danger of extinction within the 
foreseeable future throughout all of its range.
    We also evaluated whether the Texas troglobitic water slater is 
endangered or threatened in a significant portion of its range. We did 
not find any portions of the Texas troglobitic water slater'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 in the foreseeable 
future. Thus, after assessing the best available information, we 
conclude that the Texas troglobitic water slater 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 
Texas troglobitic water slater is not in danger of extinction or likely 
to become in danger of extinction within the foreseeable future 
throughout all of its range or in any significant portion of its range. 
Therefore, we find that listing the Texas troglobitic water slater 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 Texas troglobitic water slater species assessment form and 
other supporting documents on https://www.regulations.gov under Docket 
No. FWS-R2-ES-2023-0178 (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 Texas troglobitic water slater SSA 
report. The Service sent the SSA report to three independent peer 
reviewers and received two responses. Results of this structured peer 
review process can be found at https://www.regulations.gov. 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 
Edison's ascyrum, Florida (lowland) loosestrife, Florida pinesnake, 
mimic cavesnail, northern cavefish, smallscale darter, or Texas 
troglobitic water slater 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).

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. 2023-25586 Filed 11-28-23; 8:45 am]
BILLING CODE 4333-15-P


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