83368 Federal Register / Vol. 88, No. 228 / Wednesday, November 29, 2023 / Proposed Rules 

www.govinfo.gov. At this site you can 

view this document, as well as all other 

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published in the Federal Register, in 

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Authority: Program Authority: 20 U.S.C. 

1098a. 

Nasser H. Paydar, 

Assistant Secretary, Office of Postsecondary 

Education. 

[FR Doc. 2023–26198 Filed 11–28–23; 8:45 am] 

BILLING CODE 4000–01–P 

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. 

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: 

Species Docket No. 

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: 

Species Contact information 

Edison’s ascyrum, Florida (lowland) loosestrife, 

and Florida pinesnake.

Lourdes Mena, Division Manager, Florida Ecological Services Field Office, lourdes_mena@

fws.gov, 904–460–4970. 

Mimic cavesnail and Texas troglobitic water 

slater.

Karen Myers, Field Supervisor, Austin Ecological Services Field Office, karen_myers@fws.gov, 

512–937–7371. 

Northern cavefish ................................................ Lee Andrews, Field Supervisor, Kentucky Ecological Services Field Office, lee_andrews@

fws.gov, 502–695–0468 ext. 46108. 

Smallscale darter ................................................ Dan Elbert, Field Supervisor, Tennessee Ecological Services Field Office, daniel_elbert@

fws.gov, 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-ofcontact 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 


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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 speciesspecific 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 


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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 yearround 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 highmoderate 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 


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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, nonvenomous, 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 


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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 


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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-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/salinewater 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 droughtprone 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 


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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, cavedwelling 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 


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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. 


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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-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 nonphotosynthetic 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 mid1950s) 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 


ddrumheller on DSK120RN23PROD with PROPOSALS1
Federal Register / Vol. 88, No. 228 / Wednesday, November 29, 2023 / Proposed Rules 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 


ddrumheller on DSK120RN23PROD with PROPOSALS1