[Federal Register Volume 87, Number 192 (Wednesday, October 5, 2022)]
[Rules and Regulations]
[Pages 60298-60313]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-21579]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2020-0152; FF09E22000 FXES11130900000 212]
RIN 1018-BE62


Endangered and Threatened Wildlife and Plants; Removing the Snail 
Darter From the List of Endangered and Threatened Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are removing 
the snail darter (Percina tanasi), a small freshwater fish native to 
the Tennessee River watershed, from the Federal List of Endangered and 
Threatened Wildlife (List). This final rule is based on a thorough 
review of the best available scientific and commercial information 
which indicates that the threats to the species have been reduced or 
eliminated to the point that it has recovered and is no longer in 
danger of extinction or likely to become in danger of extinction in the 
foreseeable future. Therefore, the species no longer meets the 
definition of an endangered or a threatened species under the 
Endangered Species Act of 1973, as amended (Act).

DATES: This rule is effective November 4, 2022.

ADDRESSES: This final rule, the post-delisting monitoring plan, and 
supporting documents (including the recovery plan and 5-year review 
summary) are available on the internet at https://www.regulations.gov 
under Docket No. FWS-R4-ES-2020-0152 or at https://ecos.fws.gov.

FOR FURTHER INFORMATION CONTACT: Daniel Elbert, Field Supervisor, U.S. 
Fish and Wildlife Service, Tennessee Ecological Services Field Office, 
446 Neal Street, Cookeville, TN 38506; telephone 931-528-6481. Direct 
all questions or requests for additional information to ``SNAIL DARTER 
QUESTIONS'' at the address above. 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:

Executive Summary

    Why we need to publish a rule. Under the Act, a species may warrant 
removal from the Federal List of Endangered and Threatened Wildlife 
(i.e., ``delisting'') if it no longer meets the definition of an 
endangered species or a threatened species. Delisting a species can 
only be completed by issuing a rule through the Administrative 
Procedure Act rulemaking process.
    What this document does. We are delisting the snail darter (Percina 
tanasi) based on its recovery. The prohibitions and conservation 
measures provided by the Act, particularly through sections 7 and 9, 
will no longer apply to the snail darter.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered species or a threatened species because of any 
of five factors: (A) The present or threatened destruction, 
modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. We have determined that the threats 
to the species have been reduced or eliminated so that the snail darter 
no longer meets the definition of an endangered or threatened species 
under the Act.
    Under the Act, we must review the status of all listed species at 
least once every 5 years. We must delist a species if we determine, on 
the basis of the best available scientific and commercial data, that 
the species is neither a threatened species nor an endangered species. 
Our regulations at 50 CFR 424.11 identify three reasons why we might 
determine that a listed species is neither an endangered species nor a 
threatened species: (1) The species is extinct; (2) the species has 
recovered, or (3) the original data used at the time the species was 
classified were in error. Here, we have determined that the snail 
darter has recovered; therefore, we are delisting it.
    Peer review and public comment. We evaluated the species' needs, 
current conditions, and future conditions to support our September 1, 
2021, proposed rule to delist the snail darter (86 FR 48953). We sought 
comments from independent specialists to ensure that our determination 
is based on scientifically sound data, assumptions, and analyses. We 
invited these peer reviewers to comment on the proposed rule and draft 
post-delisting monitoring plan. We considered all comments and 
information we received during the public comment period on the 
proposed rule when developing this final rule.

Previous Federal Actions

    On October 9, 1975, we published a final rule in the Federal 
Register (40 FR 47505) listing the snail darter as an endangered 
species due to the threat of

[[Page 60299]]

the impoundment of the only known location of the species by the 
completion of Tellico Dam. On April 1, 1976, the Service designated 
16.5 miles (26.4 km) of the lower Little Tennessee River as critical 
habitat for the snail darter (41 FR 13926). In 1977, the critical 
habitat for the snail darter was amended to include a map (42 FR 
47840). The Snail Darter Recovery Team prepared the initial recovery 
plan for the snail darter on April 4, 1979 (Hurst et al. 1979, entire). 
The plan was revised and finalized on May 5, 1983 (Service 1983, 
entire). Due to successful translocations into the Hiawassee and 
Holston Rivers and the discovery of additional populations, we 
reclassified the snail darter from endangered to threatened and 
rescinded critical habitat on July 5, 1984 (49 FR 27510). In 2013, we 
completed a 5-year review for the snail darter. No change in the 
species' listing classification was recommended as a result of that 5-
year review. We initiated a second 5-year review for the species on 
April 11, 2019 (84 FR 14669), and on July 16, 2019, we were petitioned 
to delist the snail darter. We were already reviewing the status of the 
species as part of the 5-year review and, upon receiving the petition, 
determined that there was substantial scientific and commercial 
information indicating the delisting the snail darter may be warranted. 
On September 1, 2021, we published a proposed rule to remove the snail 
darter from the Federal List of Endangered and Threatened Wildlife (86 
FR 48953) and announced the availability of a draft post-delisting 
monitoring plan. The September 1, 2021, proposed rule to delist the 
snail darter also serves as our 5-year review, and 90-day and 12-month 
findings on the petition.

Summary of Changes From the Proposed Rule

    We considered all comments and information that we received during 
the comment period for the proposed rule to delist the snail darter (86 
FR 48953; September 1, 2021). We made minor editorial changes and 
revised various sections of the rule based on public and partner 
comments. We also incorporated an additional study (Jones et al. 2015) 
into our evaluation of the effects of climate change on the species. 
The information from this study added to the evidence of variability in 
the weather but did not change our understanding of how climate change 
will affect the snail darter overall.

Background

Taxonomy

    The snail darter is a small fish in the perch family, Percidae, and 
darter subfamily, Etheostomatinae. The species was first discovered in 
1973 (Starnes 1977, p. 1). At that time, and when listed in 1975, the 
snail darter was recognized as a new, undescribed species in the genus 
Percina and subgenus Imostoma. The species was described in 1976 as 
Percina tanasi, named after the historic Cherokee town of Tanasi, near 
where the snail darter was first discovered (Etnier 1976, p. 485). The 
snail darter has been recognized as the sister species (closest 
relative) to the stargazing darter (P. uranidea) (Etnier 1976, p. 480; 
Near and McEachran 2002, p. 8).

Population Genetics

    No studies have been completed to determine the level of gene flow 
between populations or the amount of potential inbreeding within 
populations. Because snail darters are often found in the lower 
portions of tributaries, it is likely that tributary populations are 
part of larger mainstem metapopulations (Service 2013, p. 13). It is 
not clear to what level the mainstem populations are isolated by the 
large Tennessee Valley Authority (TVA) dams and reservoirs.

Species Description

    The following description is modified from Etnier (1976, pp. 480-
485) and Etnier and Starnes (1993, pp. 587-590). The snail darter is a 
small benthic (bottom-dwelling) fish that grows to 3.55 inches (in) (90 
millimeters (mm)). The base color is brown or brownish grey with some 
green. The back has four clear black or dark brown saddle markings. 
These markings extend down the sides toward the series of blotches 
along the lateral line. A dark suborbital bar or ``teardrop'' marking 
is present below the eye. Fin rays are usually speckled, but pelvic and 
anal fins are sometimes clear. Males gain a blue-green sheen on the 
sides and belly during the breeding season when golden flecks become 
more pronounced on the cheeks and pectoral fins. Females also develop 
some gold coloring but are less bright than the males. Breeding 
tubercles (small bony protrusions) form on the rays of the elongated 
anal fin of males as well as the lower surfaces of rays of the pelvic 
fins, caudal (tail) fin, and branchiostegal (soft gill cover under 
head) rays.
    The snail darter may occur with two other Imostoma darters, the 
river darter (Percina shumardi) and the saddleback darter (P. vigil). 
The snail darter differs from the river darter by having four saddle 
markings along its back, while the latter lacks saddles altogether. 
Snail darters and river darters are often found together, but river 
darters tend to be associated with slightly larger substrate than snail 
darters (Matthews 2020, pers. comm.). While these species may share 
similar habitat, there is no evidence that they compete for resources.

Habitat

    The snail darter occurs in flowing sections of medium to large 
rivers. In these streams, snail darters are predominantly found over 
clean gravel without significant silt or plant coverage (Ashton and 
Layzer 2010, p. 615). Initially thought to require shallow, unimpounded 
portions of river to survive (Starnes 1977, pp. 21-23), snail darters 
were later found in the impounded but flowing upper sections of 
mainstem Tennessee River reservoirs (Hickman and Fitz 1978, p. 80). 
Snail darters were found in shoals at a depth of 1 to 3 feet (ft) (0.3 
to 1 meters (m)) (Starnes 1977, pp. 21-33; Ashton and Layzer 2010, 
entire). Snail darters have also been found on gravel and cobble 
patches in up to 25 ft (7.6 m) of water with regular captures at 10 to 
15 ft (3 to 5 m) deep (Ripley 1976, entire; Hickman and Fitz 1978, pp. 
80-83; Matthews 2017, pers. comm.; Matthews 2019, pers. comm.). In 
addition to large river habitats, snail darters also occupy the lower 
reaches of larger creeks, and during the breeding season, large numbers 
of darters congregate on the gravel shoals in these creeks to spawn 
(Starnes 1977, p. 64). Detailed descriptions of snail darter habitat 
can be found in Ashton and Layzer (2010, entire) and Starnes (1977, pp. 
21-33).

Life History

    The life history data presented here are modified from Etnier and 
Starnes (1993, p. 588), with additions from Hickman and Fitz (1978, pp. 
10-38) and Starnes (1977, entire). The snail darter is well adapted to 
its habitat of clean gravel substrate in large creeks and rivers. The 
saddle markings on the back of the fish act as camouflage amongst 
gravel and small cobble, and are a pattern seen in other benthic 
species (Armbruster and Page 1996, pp. 250-252). Snail darters also can 
burrow into the substrate with just their eyes exposed to escape 
predation (Etnier and Starnes 1993, p. 588). The species spawns in the 
late winter and early spring, from about February to April. Adults 
gather on shoals during the breeding season. While spawning has not 
been directly observed, it is likely

[[Page 60300]]

that the eggs are buried shallowly in the sand and gravel similar to 
how other Percina species bury their eggs. Females produce about 600 
eggs per season during multiple spawning events. Eggs hatch after 15-20 
days and produce pelagic (in the water column) larvae that drift 
considerable distances downstream. The developing larvae and juveniles 
likely use relatively calm deeper areas of rivers and reservoirs. By 
the end of summer, juveniles are about 1.6 in (40 mm) in length and 
begin migrating upstream. Some fast-growing individuals may reach 
sexual maturity in their first year, but most mature in their second 
year (Etnier and Starnes 1993, p. 588). Snail darters are short-lived 
fish that rarely survive to their fourth year. As their name implies, 
snail darters mostly feed on freshwater snails, predominantly in the 
genera Leptoxis and Lithasia, as well as caddisfly and dipteran (true 
fly) larvae (Etnier and Starnes 1993, p. 588).

Distribution

    When we listed the snail darter (40 FR 47505; October 9, 1975), the 
species was only known from about 13 miles (21 kilometers (km)) of the 
lower Little Tennessee River in Loudoun County, Tennessee. Shortly 
thereafter, the species was found in the Watts Bar Reservoir portion of 
the Tennessee River below the mouth of the Little Tennessee River, and 
efforts were made to conserve the species by translocating individuals 
into other suitable streams (Hickman and Fitz 1978, pp. 80-83). Snail 
darters were collected from the Little Tennessee River and stocked into 
the Hiwassee, Holston, Nolichucky, and Elk Rivers beginning in 1975 to 
achieve this objective. The introductions into the Nolichucky and Elk 
Rivers were halted when sharphead darters (Etheostoma acuticeps), a 
species once thought extinct, were rediscovered there, causing concern 
about competition between the two species. However, the introductions 
into the Holston and Hiwassee Rivers were successful, and it is thought 
that the populations in the French Broad and Ocoee Rivers were 
established by dispersal from these populations (Ashton and Layzer 
2008, pp. 55-56). These locations are presented on a map in figure 1, 
below.
    After the completion of Tellico Dam on the Little Tennessee River, 
snail darters were located in five additional tributaries and three 
reservoirs: Little River (1983), Big Sewee Creek (1981), Chickamauga 
Reservoir (1976), Nickajack Reservoir (1981), South Chickamauga Creek 
(Tennessee and Georgia portions) (1980), Guntersville Reservoir 
(Tennessee portion) (1981), Sequatchie River (1981), and Paint Rock 
River (Alabama portion) (1981) (Service 1983, pp. 12-19; Service 2013, 
p. 7). A survey in 2005 located the species in seven of the nine 
tributaries surveyed: French Broad River, Hiwassee River, Holston 
River, Little River, Sequatchie River, Big Sewee Creek, and South 
Chickamauga Creek (Ashton and Layzer 2008, p. 54). This survey appears 
to be the last known record of snail darters in Big Sewee Creek 
(Simmons 2019, unpublished data). In this survey, snail darters were 
not located in the Paint Rock River or Ocoee River, though they were 
discovered at both locations in later years (Kuhajda 2018, unpublished 
data). In 2007, a single snail darter was collected in Citico Creek, 
suggesting that snail darters may have persisted in the Little 
Tennessee River watershed after the dam was constructed; however, they 
were not found in follow-up surveys (Service 2013, p. 7).
    More recent survey efforts have continued to document new snail 
darter locations, though with limited information on persistence. In 
2012, two snail darters were collected in the Flint River in Alabama 
(Simmons 2019, p. 1), but they have not been found there since. In 
2015, snail darters were collected in the Elk River in Alabama and in 
Bear Creek in Alabama and Mississippi, over 100 river miles (160 km) 
from the Flint River location. To verify these collections, TVA began 
an effort to survey the mainstem Tennessee River reservoirs for snail 
darters (Simmons 2019, p. 2), collecting snail darters from six 
reservoirs in Tennessee and Alabama: Chickamauga, Nickajack, 
Guntersville, Wheeler, Pickwick, and the French Broad River arm of Fort 
Loudoun Reservoir (Simmons 2019, p. 7; TVA unpublished data). Later 
surveys of the reservoirs located juvenile snail darters in Watts Bar 
Reservoir (Matthews 2020, pers. comm.), but trawling efforts did not 
locate individuals in Tellico, Wilson, and Kentucky Reservoirs (Simmons 
2019, p. 6).
    In 2017 and 2018, an environmental DNA survey was conducted for 
snail darters in the Alabama portion of the Tennessee River Basin 
(Shollenberger 2019, p. 6). Environmental DNA (eDNA) is a surveillance 
tool used to monitor for the genetic presence of an aquatic species. 
These surveys returned positive eDNA detections in the following 
streams and reservoirs where TVA surveys had physically collected snail 
darters during previous survey efforts: Guntersville Reservoir, Wheeler 
Reservoir, Paint Rock River, Elk River, Pickwick Reservoir, and Bear 
Creek. The eDNA surveys returned negative results at locations where 
snail darters had not been collected recently, such as Wilson Reservoir 
and the Flint River, although an eDNA detection was found and then 
validated in 2020 in Shoal Creek, a tributary to Wilson Reservoir 
(Johnson 2020, p. 2).
    In summary, the snail darter's known range has greatly expanded 
since it was first discovered (see figure 1, below). At the time of 
listing in 1975, the species was only known from a small reach of the 
Little Tennessee River. By the early 1980s, new populations had been 
found or established in 10 widely dispersed locations, and in 1984, we 
reclassified the snail darter from an endangered to a threatened 
species (49 FR 27510; July 5, 1984), due largely to an increased number 
of populations and a considerable range expansion. Since 2010, 
populations in an additional two reservoirs and three tributaries have 
been discovered (Simmons 2019, pp. 1-2). As a result, snail darters are 
now considered extant in seven mainstem reservoirs of the Tennessee 
River (Fort Loudoun, Watts Bar, Chickamauga, Nickajack, Guntersville, 
Wheeler, and Pickwick) and 12 tributaries in the Tennessee River 
watershed (Holston River, French Broad River, Little River, Hiwassee 
River, Ocoee River, South Chickamauga Creek, Sequatchie River, Paint 
Rock River, Flint River (two individuals), Elk River, Shoal Creek (one 
individual), and Bear Creek). We consider the snail darter extirpated 
from the Little Tennessee River mainstem, Citico Creek, and Sewee 
Creek, and never established in the Nolichucky River.
BILLING CODE 4333-15-P

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[GRAPHIC] [TIFF OMITTED] TR05OC22.038


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BILLING CODE 4333-15-C

Evaluating Populations

    The best available scientific information does not allow us to 
determine population size for the snail darter. Therefore, our 
assessment was based on monitoring of the stream community conducted by 
TVA throughout the Tennessee River Basin using an index of biotic 
integrity (IBI) approach. The IBI uses fish community metrics, such as 
percent insectivore, to develop a score of stream health. These surveys 
target a representative sample of the overall fish assemblage rather 
than individual species, so are not designed to provide population size 
information on rare species but are useful for determining species 
persistence at a site. Occasional encounters by IBI monitoring crews 
provide information in the intervening years, but many of these surveys 
took place in wadable portions of streams, missing the deeper water 
habitats often used by the species. Where snail darters are common near 
IBI sites, surveyors intentionally avoid their habitat to reduce the 
probability of injury, which can result in artificially reduced numbers 
of the species in samples. The wide variety of methods used during 
previous survey efforts also makes comparing populations difficult. 
Surveys targeted at other species only note incidental sightings of 
snail darters, not density, and the TVA trawls have mostly been carried 
out to determine the species' presence and range (Simmons 2019, p. 1). 
However, the best available science indicates that reproducing 
populations of the species likely exist in at least 16 locations (6 
reservoirs and 10 tributaries) based on repeated collections that have 
been made at those locations, evidence of multiple age classes at those 
locations (i.e., suggesting regular recruitment into the population), 
and multiple males and females captured at those locations (see tables 
1 and 2 in Summary of Biological Status, below).

Recovery and Recovery Plan Implementation

    Section 4(f) of the Act (16 U.S.C. 1531 et seq.) directs us to 
develop and implement recovery plans for the conservation and survival 
of endangered and threatened species unless we determine that such a 
plan will not promote the conservation of the species. Under section 
4(f)(1)(B)(ii), recovery plans must, to the maximum extent practicable, 
include objective, measurable criteria which, when met, would result in 
a determination, in accordance with the provisions of section 4 of the 
Act, that the species be removed from the List.
    Recovery plans provide a roadmap for us and our partners on methods 
of enhancing conservation and minimizing threats to listed species, as 
well as measurable criteria against which to evaluate progress towards 
recovery and assess the species' likely future condition. However, they 
are not regulatory documents and do not substitute for the 
determinations and promulgation of regulations required under section 
4(a)(1) of the Act. A decision to revise the status of a species, or to 
delist a species, is ultimately based on an analysis of the best 
scientific and commercial data available and consideration of the 
standards listed in 50 CFR 424.11(e) to determine whether a species is 
no longer an endangered species or a threatened species, regardless of 
whether that information differs from the recovery plan.
    There are many paths to accomplishing recovery of a species, and 
recovery may be achieved without all of the criteria in a recovery plan 
being fully met. For example, one or more criteria may be exceeded 
while other criteria may not yet be accomplished. In that instance, we 
may determine that the threats are minimized sufficiently and that the 
species is robust enough that it no longer meets the definition of an 
endangered species or a threatened species. In other cases, we may 
discover new recovery opportunities after having finalized the recovery 
plan. Parties seeking to conserve the species may use these 
opportunities instead of methods identified in the recovery plan. 
Likewise, we may learn new information about the species after we 
finalize the recovery plan. The new information may change the extent 
to which existing criteria are appropriate for identifying recovery of 
the species. The recovery of a species is a dynamic process requiring 
adaptive management that may, or may not, follow all of the guidance 
provided in a recovery plan.
    The snail darter recovery plan (Service 1983, entire) included 
recovery criteria to indicate when threats to the species have been 
adequately addressed and prescribed actions that were thought to be 
necessary for achieving those criteria. We summarize the criteria and 
then discuss progress toward meeting the recovery criteria in the 
following sections.

Recovery Criteria

    The objective of the recovery plan is to protect and recover the 
snail darter to the point where it can be removed from the Federal List 
of Endangered and Threatened Wildlife. The recovery plan states that 
the species ``shall be considered recovered when one of the 
alternatives (A, B, or C) listed below is met and no present or 
foreseeable threats exist that could cause the species to become in 
danger of extinction'' (Service 1983, p. 27).
     Alternative A: Suitable habitat areas of the Tennessee 
River within the area from the backwaters of Wheeler Reservoir upstream 
to the headwaters of Watts Bar Reservoir are inhabited by snail darter 
populations that can survive and reproduce independently of tributary 
rivers as evidenced by documented reproduction in Watts Bar Reservoir 
or some other Tennessee River reservoir.
     Alternative B: More Tennessee River tributary populations 
of the species are discovered, and existing populations are not lost. 
The number of additional populations needed to meet this criteria would 
vary depending on the status of the new populations, but two 
populations similar to the Big Sewee Creek, South Chickamauga Creek, or 
Sequatchie River populations, or one comparable to the Hiwassee River 
population, would denote recovery.
     Alternative C: Through maintenance of existing populations 
and/or by expansion of these populations, there exist viable 
populations of snail darters in five separate streams such as Big Sewee 
Creek, Hiwassee River, South Chickamauga Creek, Sequatchie River and 
Paint Rock River. (For this alternative, ``viable populations'' means 
that population monitoring over a 10-year period (biannual sampling) 
indicates that the snail darter is reproducing (at least two year 
classes present each year sampled) and that the population is either 
stable or expanding. For some populations, existing data may be used to 
meet this requirement.)

Achievement of Recovery Criteria

    Alternative A of the recovery criteria requires that snail darters 
be present in suitable habitats within reservoirs from Wheeler 
Reservoir upstream to Watts Bar Reservoir and evidence of reproduction 
within reservoirs independent of tributaries in at least one reservoir. 
We conclude that Alternative A has been met based on collection of 
seven permanent mainstem populations (Pickwick, Wheeler, Guntersville, 
Nickajack, Chickamauga, Watts Bar, and Fort Loudoun reservoirs) and 
evidence of reproduction independent of tributaries in Chickamauga, 
Nickajack, and Wheeler reservoirs (see tables 1 and 2 in Summary of 
Biological Status,

[[Page 60303]]

below, and figure 1 in Background, above). These populations represent 
multiple reservoirs, rivers and span at least three physiographic 
regions (Highland Rim, Cumberland Plateau, and Ridge and Valley) 
(Etnier and Starnes 1993, p. 3; Mettee et al. 1996, p. 5).
    Our assessment of the tributary populations of snail darters 
supports the determination that Alternative B has also been met. 
Alternative B of the recovery criteria requires the discovery or 
establishment of at least two new tributary populations similar to the 
Big Sewee Creek, South Chickamauga Creek, or Sequatchie River 
populations or one comparable to the Hiwassee River population. In our 
analysis, we determined that 10 tributary populations are extant that 
have a moderate or high resilience (see table 1, below). Four of these 
(French Broad River, Ocoee River, Elk River, and Bear Creek) have been 
found or established since the recovery plan was finalized. The largest 
new population occurs in the lower French Broad River. The founders of 
this population were likely migrants or juveniles from the stocked 
population in the Holston (Service 2013, p. 14). Snail darters have 
been collected across at least 21.8 miles (35.1 km) of the French Broad 
River and across 19 miles (30.5 km) of the Hiwassee River (Ashton and 
Layzer 2008, pp. 54-55; Kuhajda 2018, supplementary data; TVA, 
unpublished data). Therefore, the requirement to discover or establish 
a population comparable to the Hiwassee River population has been met.
    Additionally, Alternative B gives the option of two tributary 
populations comparable to Big Sewee Creek, South Chickamauga Creek, and 
Sequatchie River. The current populations in the Ocoee River and Bear 
Creek are comparable to the Big Sewee Creek, South Chickamauga Creek, 
and Sequatchie River populations that existed at the time the recovery 
plan was finalized based on captures and occupied stream length.
    Since 2011, snail darters have been found consistently in the Ocoee 
River by TVA IBI crews, appearing in every biannual sample since 2015. 
Snail darters have been collected across 5.9 miles (9.5 km) of the 
Ocoee River, and collections of snail darters in the Hiwassee River 
near the mouth of the Ocoee suggest that they may occupy more of the 
river.
    Snail darters have only been collected as individuals or pairs, but 
the lower portion of Bear Creek is in the Gulf Coastal Plain 
physiographic region, so preferred habitat is more limited than in 
other streams. Individuals have been collected across 5.8 miles (9.3 
km) of Bear Creek, but trawling collections near the mouth of Bear 
Creek and eDNA detections in the lower parts of the Bear Creek system 
and at its mouth suggest that snail darters may occur in an additional 
25 miles (40 km) of the creek (Simmons 2019, supplementary data; 
Shollenberger 2019, pp. 14-16).
    Since 2015, snail darters have been collected in 1.4 miles (2.3 km) 
of the Elk River in Tennessee. Snail darters may also occur in the 
Alabama portion of the Elk River over more than 20 river miles of free-
flowing stream down to the portion of the river inundated by Wheeler 
Reservoir (Simmons 2019, supplementary data; Shollenberger 2019, pp. 
14-16).
    Our assessment of the tributary populations of the snail darter 
supports the determination that Alternative B has been met based on the 
establishment of the French Broad River population that is comparable 
to the Hiwassee population. Additionally, the Ocoee River, Bear Creek, 
and Elk River populations are comparable to the Big Sewee Creek 
historical population, which was found across 4.2 miles of stream, 
exceeding the prescription in Alternative B for at least one additional 
large population or two additional small populations.
    The intent of Alternative C has been fulfilled because the 
documented conditions are functionally equivalent to those prescribed. 
This alternative of the recovery criteria calls for the maintenance of 
viable populations in five separate streams. The definition for viable 
populations in the 1983 recovery plan requires biannual monitoring over 
a 10-year period with enough data to demonstrate a stable or increasing 
population size and evidence of reproduction indicated by the presence 
of at least two year classes present in each year sampled. The best 
available monitoring data do not allow us to determine whether 
populations meet this definition, because most of our collections come 
from TVA IBI surveys that are not species-specific. However, our 
analysis of the tributary populations found 10 populations that were 
considered at least moderately resilient (see table 1 in Summary of 
Biological Status, below), which we conclude is equivalent to a 
determination that the populations are viable. Of these, nine met the 
requirement of Alternative C that at least two year classes be present. 
The discovery of populations in Bear Creek, Elk River, Wheeler 
Reservoir, and Pickwick Reservoir since 2009 shows evidence of either 
species expansion or growth of existing populations to the level of 
detection (see table 2 in Summary of Biological Status, below). The 
presence of resilient populations in 10 tributaries and 7 mainstem 
reservoirs across four physiographic regions provides evidence of high 
redundancy and representation for the species (see further explanation 
of these terms in Analytical Framework, below).
    In summary, alternative pathways to recovery A and B have been met 
or exceeded, and the intent of alternative C has been fulfilled. The 
recovery plan only required one of the three alternative pathways to be 
met. Therefore, we conclude that the recovery criteria established by 
the plan have been surpassed.

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations in title 50 of the Code of Federal Regulations set forth 
the procedures for determining whether a species is an ``endangered 
species'' or a ``threatened species,'' issuing protective regulations 
for threatened species, and designating critical habitat for threatened 
and endangered species. In 2019, jointly with the National Marine 
Fisheries Service, the Service issued final rules that revised the 
regulations in 50 CFR parts 17 and 424 regarding how we add, remove, 
and reclassify threatened and endangered species and the criteria for 
designating listed species' critical habitat (84 FR 45020 and 84 FR 
44752; August 27, 2019). At the same time the Service also issued final 
regulations that, for species listed as threatened species after 
September 26, 2019, eliminated the Service's general protective 
regulations automatically applying to threatened species the 
prohibitions that section 9 of the Act applies to endangered species 
(collectively, the 2019 regulations).
    However, on July 5, 2022, the U.S. District Court for the Northern 
District of California vacated the 2019 regulations (Center for 
Biological Diversity v. Haaland, No. 4:19-cv-05206-JST, Doc. 168 (N.D. 
Cal. July 5, 2022) (CBD v. Haaland)), reinstating the regulations that 
were in effect before the effective date of the 2019 regulations as the 
law governing species classification and critical-habitat decisions. 
Accordingly, in developing the analysis contained in this final rule, 
we applied the pre-2019 regulations, which may be reviewed in the 2018 
edition of the Code of Federal Regulations at 50 CFR 17.31, 17.71, 
424.02, 424.11(d) and (e), and 424.12(a)(1) and (b)(2). Because of the 
ongoing litigation regarding the court's vacatur of the 2019 
regulations,

[[Page 60304]]

and the resulting uncertainty surrounding the legal status of the 
regulations, we also undertook an analysis of whether the final rule 
would be different if we were to apply the 2019 regulations. That 
analysis, which we described in a separate memo in the decisional file 
and posted on https://www.regulations.gov, concluded that we would have 
reached the same decision if we had applied the 2019 regulations. This 
is because both before and after the 2019 regulations, the standard for 
whether a species warrants delisting has been, and will continue to be, 
whether the species meets the definition of an endangered species or a 
threatened species. Further, we concluded that our determination of the 
foreseeable future would be the same under the 2019 regulations as 
under the pre-2019 regulations.
    On September 21, 2022, the U.S. Circuit Court of Appeals for the 
Ninth Circuit stayed the district court's July 5, 2022, order vacating 
the 2019 regulations until a pending motion for reconsideration before 
the district court is resolved (In re: Cattlemen's Ass'n, No. 22-
70194). The effect of the stay is that the 2019 regulations are the 
governing law. Because of our desire to remove regulatory burdens in a 
timely manner whenever species no longer meet the definition of an 
endangered or threatened species, rather than revise the proposal in 
response to the Ninth Circuit's decision for submission of a final rule 
to the Federal Register, we hereby adopt the analysis in the separate 
memo that applied the 2019 regulations as our primary justification for 
the final rule. However, due to the continued uncertainty resulting 
from the ongoing litigation, we also retain the analysis in this 
preamble that applies the pre-2019 regulations and we conclude that, 
for the reasons stated in our separate memo analyzing the 2019 
regulations, this final rule would have been the same if we had applied 
the 2019 regulations.
    The Act defines an ``endangered species'' as a species that is in 
danger of extinction throughout all or a significant portion of its 
range, and a ``threatened species'' as a species that is likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range. The Act requires that we 
determine whether any species is an ``endangered species'' or a 
``threatened species'' because of any of the following factors:
    (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects. The determination to delist a 
species must be based on an analysis of the same five factors.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the species' expected response and 
the effects of the threats--in light of those actions and conditions 
that will ameliorate the threats--on an individual, population, and 
species level. We evaluate each threat and its expected effects on the 
species, then analyze the cumulative effect of all of the threats on 
the species as a whole. We also consider the cumulative effect of the 
threats in light of those actions and conditions that will have 
positive effects on the species--such as any existing regulatory 
mechanisms or conservation efforts. The Secretary determines whether 
the species meets the definition of an ``endangered species'' or a 
``threatened species'' only after conducting this cumulative analysis 
and describing the expected effect on the species now and in the 
foreseeable future.
    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Because 
the decision in CBD v. Haaland vacated our 2019 regulations regarding 
the foreseeable future, we refer to a 2009 Department of the Interior 
Solicitor's opinion entitled ``The Meaning of `Foreseeable Future' in 
Section 3(20) of the Endangered Species Act'' (M-37021). That 
Solicitor's opinion states that the foreseeable future ``must be rooted 
in the best available data that allow predictions into the future'' and 
extends as far as those predictions are ``sufficiently reliable to 
provide a reasonable degree of confidence in the prediction, in light 
of the conservation purposes of the Act.'' Id. at 13.
    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' responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.

Analytical Framework

    To assess species viability, we use the three conservation biology 
principles of resiliency, redundancy, and representation (Shaffer and 
Stein 2000, pp. 306-310). Briefly, resiliency supports the ability of 
the species to withstand environmental and demographic stochasticity 
(for example, wet or dry, warm or cold years), redundancy supports the 
ability of the species to withstand catastrophic events (for example, 
droughts, large pollution events), and representation supports the 
ability of the species to adapt over time to long-term changes in the 
environment (for example, climate change). In general, the more 
resilient and redundant a species is and the more representation it 
has, the more likely it is to sustain populations over time, even under 
changing environmental conditions. Using these principles, we 
identified the species' ecological requirements for survival and 
reproduction at the individual, population, and species levels and 
described the beneficial and risk factors influencing the species' 
viability.

Summary of Biological Status

Resiliency Analysis

    As explained above in Evaluating Populations, the existing data 
available do not allow us to estimate population sizes for snail 
darter. However,

[[Page 60305]]

collections over multiple years and the presence of multiple age 
classes provide evidence of persistence in tributaries throughout the 
snail darter's range. In the reservoirs, the capture of multiple 
individuals and evidence of multiple age classes typically represents a 
sustainable population. Where available, presence of snail darters in 
breeding condition is used as additional evidence of spawning, because 
snail darters move onto the spawning ground before spawning commences 
(Starnes 1977, p. 64). We used IBI scores from fixed monitoring 
stations to address stream health where possible for tributary 
populations. These scores are generated from fish assemblage surveys 
throughout the Tennessee River Valley that rank streams from 12 to 60 
(poor to excellent) based on metrics such as total number of species, 
proportions of intolerant and tolerant species, and the numbers of 
species in various ecological guilds (TVA 2005, pp. 5-7). We use these 
measures to describe the resiliency of the snail darter populations and 
their contributions to the species' recovery.
    Tributary Resiliency--We characterized snail darter population 
resiliency in 14 tributaries (11 extant populations, one extirpated, 
and two apparently not established with only one collection each and no 
evidence of reproduction) using data related to three factors: 
collections in multiple years since 2009, presence of multiple year 
classes in these samples, and TVA IBI scores for the tributary 
populations (see resiliency scores for these factors in table 1, 
below). Detection of the species in multiple years provides evidence of 
persistence within a tributary. Consistent collections also indicate 
population numbers that are high enough to be detected using non-
depletion methods (not every fish in a sample reach is caught), which 
is relevant for species like the snail darter that are difficult to 
capture with standard fish sampling equipment. The presence of multiple 
age classes is evidence of successful reproduction in the population. 
Given that snail darters only live 4 years and likely do not mature 
until their second year, it would only take a few years of failed 
reproduction for a population to be extirpated (Etnier and Starnes 
1993, p. 588). We reviewed the available data to determine population 
scores for each of the tributaries. The best available data are not 
sufficient to determine snail darter population size or trends due to 
the typically small numbers collected at any given site; however, we 
can address resiliency of the tributary populations by looking at 
persistence over time and evidence of reproduction. To do this, we used 
data from snail darter collections and observations from TVA and 
Conservation Fisheries, Inc., and data compiled by the Tennessee 
Aquarium Conservation Institute.
    We used IBI scores to address stream community health where 
possible for tributary populations. Measuring the overall fish 
community is a way to investigate habitat quality, water quality, and 
ecosystem stability by proxy of the fish that live in the stream. The 
IBI incorporates 12 metrics to measure fish community health based on 
the number of species or proportion of individuals in different guilds 
(group of species with similar life history) compared to what is 
expected in a reference condition stream. These metrics are adjusted 
based on stream size and physiographic region in order to be relevant 
to the differences in natural conditions across the Tennessee River 
Basin. Each metric is assigned a value matching a ranking of good (5), 
fair (3), or poor (1). The 12 metrics are then summed for each, 
yielding an overall rating of the stream community health. An IBI score 
of 12 to 22 equates to a very poor rating, 28 to 34 to a poor rating, 
40 to 44 to a fair rating, 48 to 52 to a good rating, and 58 to 60 to 
an excellent rating. Scores between these ranges received intermediate 
ratings (TVA 2005, entire). To determine potential IBI trends, we 
compared overall IBI scores for sites within the range of snail darters 
in each tributary from 2009 to 2019. Roughly half of the tributaries 
(French Broad River, Little River, Hiwassee River, Ocoee River, Elk 
River, and Flint River) showed some improvement during the 1999-2009 
period, but during the 2009-2019 analysis period, the communities in 
all of the tributaries were mostly stable.
    We combined the population metrics to give a population score (low, 
medium, or high), and the habitat metrics combined to form a composite 
habitat score (low, medium, or high). These scores are compiled in 
table 1, below. The population and habitat scores were averaged to 
provide the overall resilience score. Tributaries with multiple 
collections (of several fish each collection) and multiple age classes 
over the 12-year period were ranked high; conversely, those with only 
one collection and no evidence of reproduction were considered not 
established. Age classes were assigned by body length, based on life-
history studies (Starnes 1977, pp. 47-63; Hickman and Fitz 1978, pp. 
10-19). Sites with multiple collections but only one age class were 
ranked low. Tributaries with good or better IBI scores that were stable 
or improving were then ranked high, and tributaries with fair IBI 
scores with stable or improving conditions were ranked moderate. 
Overall resilience was calculated by averaging the column scores. Where 
snail darters had been extirpated or not established, IBI scores were 
not incorporated. While the habitat in Little River is very good, we 
found that the low numbers (three or fewer individuals in any single 
observation) of snail darters captured and the lack of multiple age 
classes did not warrant categorizing the Little River population as 
moderate or high. Our results of the tributary resiliency analysis are 
summarized in table 1.

                           Table 1--Tributary Population Resiliency Based on Collection Data and TVA IBI Scores From 2009-2019
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                   Multiple        Multiple age                                                                              Overall
          Tributary               detections          classes      Population score      IBI score        IBI trend      Habitat score      resiliency
--------------------------------------------------------------------------------------------------------------------------------------------------------
Holston River................  Yes.............  Yes.............  High............  Fair............  Stable.........  Moderate.......  Moderate/high.
French Broad River...........  Yes.............  Yes.............  High............  Fair/good.......  Stable or        High...........  High.
                                                                                                        improving.
Little River.................  Yes.............  No..............  Low.............  Good/excellent..  Stable.........  High...........  Low.
Citico Creek.................  No..............  No..............  Not established.  Good............  Stable.........  High...........  Not
                                                                                                                                          established.
Big Sewee Creek..............  No..............  No..............  Extirpated......  Poor/fair.......  Stable.........  Low............  Extirpated.
Hiawassee River..............  Yes.............  Yes.............  High............  Good/excellent..  Stable.........  High...........  High.
Ocoee River..................  Yes.............  Yes.............  High............  Fair............  Stable.........  Moderate.......  Moderate/high.
South Chickamauga Creek......  Yes.............  Yes.............  High............  Fair............  Stable or        Moderate.......  Moderate/high.
                                                                                                        declining.
Sequatchie River.............  Yes.............  Yes.............  High............  Fair............  Stable or        Moderate.......  Moderate/high.
                                                                                                        declining.
Paint Rock River.............  Yes.............  Yes.............  High............  Fair/good.......  Stable.........  High...........  High.
Flint River..................  No..............  No..............  Not established.  Fair............  Insufficient     Moderate.......  Not
                                                                                                        data.                             established.
Elk River....................  Yes.............  Yes.............  High............  Fair/good.......  Stable or        High...........  High.
                                                                                                        improving.
Shoal Creek..................  No..............  No..............  Not established.  Good............  Stable or        High...........  Not
                                                                                                        improving.                        established.

[[Page 60306]]

 
Bear Creek...................  Yes.............  Yes.............  High............  Good............  Stable or        High...........  High.
                                                                                                        improving.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Reservoir Resiliency--Using the data available from the TVA snail 
darter trawl surveys (Simmons 2019, p. 3), we analyzed resiliency of 
the reservoir populations based first on the number of individuals 
captured and second, evidence of reproduction with evidence of 
reproduction established either through presence of multiple age 
classes, adults in spawning condition (gravid females and/or males 
flowing milt [sperm]), or juveniles. To categorize number of 
individuals, we classified collections of 0-4 individuals as low, 5-9 
as moderate, and 10 or more as high. To classify reproduction, given 
the limited sampling effort to date, collection of more than one age 
class or other evidence of reproduction resulted in a high rating in 
the reproduction metrics. Collection of only one age class or no other 
evidence of reproduction resulted in a low rating. Similar to the 
stream population, overall resilience was calculated by averaging the 
scores of the number collected and reproduction metrics. Results are 
summarized below in table 2.

                                   Table 2--Reservoir Population Collections Based on TVA Benthic Trawls, 2016-2019 *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Population score  (number     Age
              Reservoir                       collected)          classes   Evidence of  reproduction      Reproduction score       Overall resilience
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fort Loudoun........................  Low (2)..................          2  No.......................  High.....................  Moderate.
Watts Bar...........................  Low (3)..................          1  Yes......................  High.....................  Moderate.
Chickamauga.........................  Low (4)..................          2  Yes......................  High.....................  Moderate.
Nickajack...........................  High (11)................          2  Yes......................  High.....................  High.
Guntersville........................  High (33)................          2  No.......................  High.....................  High.
Wheeler.............................  High (18)................          2  Yes......................  High.....................  High.
Wilson..............................  Low (0)..................          0  No.......................  N/A......................  Not established.
Pickwick............................  High (18)................          3  No.......................  High.....................  High.
Kentucky............................  Low (0)..................          0  No.......................  N/A......................  Not established.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Age classes based on total length measurements from Hickman and Fritz (1978). Evidence of reproduction is based on capture of juvenile individuals,
  adults in spawning condition, or multiple age classes (Simmons 2019, p. 7).

    For the purpose of evaluating the snail darter's status, we 
considered those tributaries that ranked moderate or high as 
contributing to resiliency. Because of the limited amount of reservoir 
sampling that has been completed, we considered those reservoir 
populations that had evidence of reproduction present as permanent, 
independent populations (Simmons 2019, p. 2) that contribute to 
resiliency. We, therefore, considered 7 reservoir populations (Fort 
Loudoun, Watts Bar, Chickamauga, Nickajack, Guntersville, Wheeler, and 
Pickwick) and 10 tributary populations (Holston, French Broad, Little, 
Hiwassee, Ocoee, Sequatchie, Paint Rock, and Elk Rivers, and South 
Chickamauga and Bear Creeks) as contributing to species resiliency. We 
did not count Wilson Reservoir or Kentucky Reservoir toward resiliency 
because snail darters had never been collected there despite trawling 
efforts. While Watts Bar is only represented by three juveniles, their 
collection far from any large tributaries is evidence of reproduction 
within the reservoir. We did not consider Citico Creek, Big Sewee 
Creek, Flint River, or Shoal Creek as contributing toward resiliency 
either because the species had not been collected there within the 
analysis period despite multiple efforts (Big Sewee Creek, Citico 
Creek) or because a single snail darter had been found on only one 
occasion (Shoal Creek, Flint River); therefore, we considered the 
populations to be not established in those locations (see table 1, 
above).

Analysis of Redundancy and Representation

    With discoveries of new tributary and reservoir populations, the 
known redundancy and representation of the snail darter has expanded 
during the analysis period. When we listed the species (40 FR 47505; 
October 9, 1975), it had very low redundancy and representation because 
only one population was known from several miles of the Little 
Tennessee River, in the Ridge and Valley physiographic region. 
Currently, the species is known across more than 400 miles (640 km) of 
the Tennessee River Valley, with moderately to highly resilient 
populations in 9 tributaries and 7 reservoirs, providing a level of 
redundancy that helps shield the species from localized stochastic 
events.
    While we do not have population genetic data for the snail darter, 
we can look at the species' ability to adapt to changes in the 
environment (representation) by looking at its distribution across a 
range of habitats and physiographic regions. Resilient populations are 
currently known from streams ranging in size from mid-sized creeks to 
the large Tennessee River itself, with collections in depths ranging 
from less than 3 ft (1 m) to 25 ft (7.6 m). These populations occur in 
reservoirs and tributaries with these conditions in four different 
physiographic regions (Ridge and Valley, Cumberland Plateau, Highland 
Rim, and Gulf Coastal Plain). This wide range of habitat use and 
geographic distribution helps to demonstrate the snail darter's 
adaptability to changing environmental pressures (representation).

Summary of Factors Affecting the Species

    A recovered species is one that no longer meets the Act's 
definition of an endangered species or a threatened species. 
Determining whether the status of a species has improved to the point 
that it can be delisted or downlisted

[[Page 60307]]

requires consideration of the same five factors identified above for 
listing a species. When we initially listed the snail darter as 
endangered in 1975, the only identified threat influencing its status 
was the modification and loss of habitat and curtailment of range 
(Factor A) caused by the completion of Tellico Dam and the flooding of 
the entire known range of the species. When we reclassified the species 
as threatened in 1984, we evaluated a more complete list of factors 
based on improved knowledge of the snail darter's range and life 
history. These factors included threats to habitat such as shipping 
activities in the mainstem Tennessee River, impacts from development in 
some of the tributaries such as South Chickamauga Creek, threats from 
agricultural runoff and channelization in streams like the Elk River, 
impacts from coal mining in the Sequatchie River watershed, and 
chemical spills in the Hiwassee and Ocoee watersheds (Factor A); 
excessive collection associated with the notoriety of the species 
(Factor B); and protections afforded the species by State and Federal 
laws (Factor D). The following analysis evaluates these previously 
identified threats, any other threats currently facing the species that 
we have identified, as well as any other threats that are reasonably 
likely to affect the species in the foreseeable future.
    To establish the foreseeable future for the purpose of evaluating 
trends in the threats and the species' responses, we analyzed trends 
from historical data on distribution and abundance, ongoing 
conservation efforts, factors currently affecting the species, and 
predictions of future climate change. When combined with our knowledge 
of factors affecting the species (see discussion below), available data 
allow us to reasonably predict future conditions, albeit with 
diminishing precision over time. Given our understanding of the best 
available data, for the purposes of this rule, we consider the 
foreseeable future for the snail darter to be approximately 30 years. 
We determined that we can reasonably predict the threats to the species 
and the species' response during this timeframe based on climate 
vulnerability assessments through 2050, the planning horizon of the 
reservoir release improvement program (RRIP), and enough time for the 
species to respond based on biology and lifespan.
    As noted above, when the species was reclassified from endangered 
to threatened (49 FR 27510; July 5, 1984), the reclassification rule 
identified additional threats to habitat in the additional populations 
established or discovered since the original listing (40 FR 47505; 
October 9, 1975). These included threats from shipping activities in 
the mainstem Tennessee River, impacts from development in some of the 
tributaries such as South Chickamauga Creek, threats from agricultural 
runoff and channelization in streams like the Elk River, impacts from 
coal mining in the Sequatchie River watershed, and chemical spills in 
the Hiwassee and Ocoee watersheds.
    One of the biggest factors still affecting the snail darter is the 
impoundment of large portions of the Tennessee River Valley. TVA 
operates 9 dams on the mainstem Tennessee River and 38 dams on 
tributaries to the Tennessee River. These impoundments create large 
areas of deep, still water that do not meet the habitat needs of the 
snail darter. Snail darters are limited in the depth they can occupy by 
the presence of food resources. Snails, the darter's preferred prey, 
live only in water shallow enough for light to penetrate and allow 
algae to grow on the substrate, about 15-20 ft (5-7 m) in much of the 
Tennessee mainstem. Impoundment also reduces stream flow and allows 
fine sediments to settle out, which can cover the clean gravel habitats 
needed by snail darters. Additionally, these dams were initially 
operated with a hydropeaking strategy, only releasing water when needed 
to generate electricity or maintain reservoir level or flood storage 
capacity. In addition, many of these releases came from the water 
levels within the reservoir that held cold, oxygen-deficient water. 
Collectively, these factors created conditions in the tailwaters that 
negatively affected water quality, food availability, and fish 
diversity.
    Given the long operational lifespan of dams (more than 100 years), 
it is nearly certain that the TVA reservoirs will be in place for the 
foreseeable future. However, beginning in 1981, TVA began studies to 
improve conditions in the tailwaters of their dams. The cold, oxygen-
deficient water released from the bottom of many of the dams created 
conditions that eliminated many fish and mussel species from these 
areas. Through the RRIP, TVA began implementing strategies to increase 
minimum flow, dissolved oxygen, and, in some cases, temperature, in the 
tailwaters of their dams beginning in 1991 (Bednarek and Hart 2005, p. 
997). In 2002, TVA conducted a reservoir operation study to consider 
how to implement these changes across the basin to improve the health 
of the river (TVA 2004, p. ES-3). The result was to manage the river 
based on minimum flows instead of reservoir level and improve tailwater 
conditions. These changes have resulted in significant improvements in 
biological and abiotic variables and increases in fish and invertebrate 
diversity in many TVA dam tailwaters (Layzer and Scott 2006, entire; 
Bednarek and Hart 2005, entire; Scott et al. 1996, entire). These 
improvements have likely resulted in improved conditions for the snail 
darter and may have contributed to improvements to the species' status 
within tailwaters since the 1990s, across more than 400 miles (640 km) 
of the mainstem of the Tennessee River. Since the RRIP is based on 
ecologically meaningful parameters in the tailwaters, such as dissolved 
oxygen and temperature, this program may be able to provide some 
resiliency to a warming climate and precipitation variability in the 
future, especially if TVA adjusts the program to maintain the needed 
conditions in the tailwaters. The reservoir operation study is planned 
along an approximately 25-year timeline, extending to 2030 (TVA 2004, 
p. ES-4). However, given the presence of at least 10 other listed 
aquatic species in the tailwaters of the mainstem Tennessee River 
reservoirs and the complexities of changing the operations plan, it is 
highly likely that TVA will continue RRIP as part of its compliance 
with the Act for these other species beyond the timeline of the 
environmental impact statement (EIS) and biological opinion that were 
prepared under section 7 of the Act before alterations were made to dam 
release management. For these same reasons, TVA will likely incorporate 
RRIP to protect federally listed mussels when it revisits its EIS 
around 2030, and because the current EIS's term is 25 years, it is 
reasonable to assume TVA will issue another 25-year EIS. Therefore, we 
anticipate that the conditions benefiting the snail darter will 
continue through at least midcentury (Baxter 2020, pers. comm.). 
Overall, the persistence and expansion of snail darter populations in 
the mainstem since the 1970s indicate greater resiliency in these 
habitats than was considered at the time of listing, particularly now 
with the implementation of TVA's RRIP.
    Anthropogenic changes to the land can also negatively impact the 
snail darter and its habitats. Sedimentation is one of the biggest 
threats to water quality in the Tennessee River Valley, including in 
streams occupied by snail darters. Big Sewee Creek has been impacted by 
sedimentation from persistent farming in the watershed, reducing the 
amount and quality of

[[Page 60308]]

gravel habitat in the stream. The predominant agricultural activities 
contributing to sedimentation in Big Sewee Creek (livestock pasture and 
row crops) are exempt from many State and Federal regulations designed 
to reduce sediment runoff, and these activities are likely to continue 
into the future. Therefore, we do not expect this population to 
reestablish unless habitat conditions improve in the future. 
Sedimentation from agriculture and development is also considered a 
concern in the lower Little Tennessee River, Sequatchie River, South 
Chickamauga Creek, and Paint Rock River watersheds. Watershed-level 
efforts have been conducted to address sedimentation issues in some of 
the tributaries where snail darters have been found. The South 
Chickamauga Creek Land Treatment Watershed Project, an effort of the 
Natural Resources Conservation Service of the U.S. Department of 
Agriculture (USDA), began in 2001, to reduce the runoff of sediment and 
nutrients in the watershed by installing animal waste management 
systems (see 65 FR 44519; July 18, 2000). Additionally, the Limestone 
Valley Resource Conservation and Development Council is working with a 
wide variety of partners to implement the South Chickamauga Creek 
Headwaters Management Plan, developed in 2012, to address water quality 
issues (Smith and Huser 2012, pp. i-3). In the Paint Rock River, The 
Nature Conservancy designated a ``landscape conservation area'' and 
worked to address sedimentation issues from agriculture throughout the 
watershed, resulting in improved conditions for aquatic fauna 
(Throneberry 2019, unpublished data). Many of these efforts include 
restoring natural stream channel characteristics where streams have 
been channelized. These efforts have been undertaken outside of 
species-specific recovery efforts for the snail darter, and they are 
likely to continue regardless of the delisting of the species. Other 
small-scale efforts have been undertaken to reduce sedimentation in 
many of the other tributaries inhabited by snail darters. It is likely 
that sedimentation has resulted in the extirpation of snail darters 
from Big Sewee Creek, but there is some potential for recolonization by 
individuals from Chickamauga Reservoir if habitat conditions improve.
    Urban and suburban development may impact the snail darter as well. 
Increases in the amount of impervious surfaces associated with 
development increase runoff to streams, destabilize hydrology, and 
increase water temperature. Additionally, residential and commercial 
development are associated with increased runoff of lawn and automotive 
chemicals into the streams (Matthaei and Lang 2016, p. 180; Walsh et 
al. 2005, p. 707). The snail darter tributaries currently most impacted 
by development and the associated chemical and sediment runoff are 
South Chickamauga Creek in Chattanooga, Tennessee; Flint River in 
Huntsville, Alabama; and Little River in Maryville, Tennessee. Based on 
the SLEUTH (Slope, Land use, Excluded area, Urban area, Transportation, 
Hillside area) model, these areas are anticipated to have increased 
suburban and urban growth in the next 30 years, which might further 
impact South Chickamauga Creek, Flint River, and Little River; there is 
also the potential for increased urban impacts to the Sequatchie River 
and Paint Rock River watersheds associated with the growth of 
Chattanooga and suburban development from Huntsville, respectively 
(Terando et al. 2014, pp. 1-3). However, based on the moderate 
resilience of snail darters in South Chickamauga Creek (see table 1, 
above), some evidence supports a conclusion that the species is 
resilient to the impacts of urbanization.
    Additionally, the Thrive Regional Partnership is a group working to 
promote responsible growth in a 16-county region in the Greater 
Chattanooga area. The partnership's goal is to improve communities 
while maintaining healthy ecosystems. Thrive has identified portions of 
streams and surrounding land that are key to preserving and enhancing 
water quality in the region of interest, with the goals of conserving 
50 percent of unprotected forest and improving water quality in at 
least 50 percent of polluted streams by 2055. The area covered by this 
initiative includes portions of the Big Sewee Creek, South Chickamauga 
Creek, Sequatchie River, and Paint Rock River watersheds (Thrive 
Regional Partnership 2019, entire).
    The threat of chemical and industrial spills was raised as a 
potential threat in the downlisting rule (49 FR 27510; July 5, 1984). 
The range of the snail darter is crossed by several major highways and 
railroad lines, making the possibility of a spill during transport an 
ongoing risk. Such spills have occurred as recently as 1991 in the 
Hiwassee River. While spills may have severe impacts locally, they are 
unlikely to affect the species as a whole given its wide range in the 
mainstem of the Tennessee River and several tributaries (Service 2013, 
p. 18). Furthermore, the Ocoee River has suffered from industrial and 
mine runoff from the historical copper extraction in the watershed. 
Within the Ocoee River watershed, concerted efforts have been made to 
clean up industrial and mine-related pollution, resulting in much 
improved water quality and a healthier ecosystem which may have 
contributed to the increased numbers of snail darters seen in that 
river since the Service's 2013 5-year review (Service 2013, p. 12; 
Simmons 2019, unpublished data).
    The threat to snail darters from coal mining in the Sequatchie 
Valley has been greatly reduced since the recovery plan was completed. 
Mining for coal in the Sequatchie Valley ceased in the 1990s, and since 
that time, there have been efforts to remediate acid mine drainage in 
the area. Currently, there are no active coal mining permits in the 
Sequatchie Valley (Office of Surface Mining Reclamation and Enforcement 
(OSMRE) 2016, p. 34; Interstate Technology & Regulatory Council (ITRC) 
2010, entire).
    The Tennessee River is a major inland shipping corridor, and in the 
downlisting rule (49 FR 27510; July 5, 1984), activities associated 
with barge traffic were considered to potentially threaten snail 
darters through habitat alterations in the mainstem Tennessee River 
reservoirs. Barge and large boat wakes can result in significant bank 
erosion along the river. Within the mainstem reservoirs, bank 
stabilization efforts have occurred in some significantly impacted 
areas and reduced sedimentation at those locations, but there is no 
concerted plan to address this source of sediment across the Tennessee 
River Basin. However, there is some evidence that areas of consistent 
traffic, such as barge mooring cells, may provide areas of silt-free 
habitat swept clean by tug engines (Matthews 2017, pers. comm.; Walker 
and Alford 2016, p. 1101).
    In summary, while effects to snail darter habitat (Factor A) 
associated with continued urbanization and agriculture are certain to 
persist into the foreseeable future, efforts are being made to reduce 
the impact to many of the tributaries inhabited by snail darters. 
Additionally, snail darters appear to be resilient to current levels of 
urbanization and agriculture, including practices such as 
channelization, in certain tributaries such as South Chickamauga Creek 
and Sequatchie River. In the Sequatchie River, the threat from coal 
mining is reduced with the cessation of mining in the valley and 
ongoing reclamation efforts. The mainstem populations are less 
susceptible to sedimentation and runoff associated with agriculture and 
urbanization due to the buffering

[[Page 60309]]

capacity of the larger river, but they still may be affected by bank 
erosion and industrial transport along the Tennessee River. However, 
population stability and apparent expansion in the mainstem since the 
1970s demonstrate the resiliency of the snail darter within these 
habitats, especially with the implementation of TVA's RRIP.
    At the time of the downlisting rule (49 FR 27510; July 5, 1984), 
the Service projected that the notoriety of the snail darter could 
result in an increase in illegal collection (Factor B); however, no 
such activities have been observed or documented since that rule was 
published. Snail darters receive some protection against collection 
from the States. The species is listed as threatened in Tennessee, 
endangered in Georgia, and protected as a non-game species in Alabama 
and Mississippi. These protections require State permits for the 
collection of the species.
    The snail darter's habitat is also protected by State water quality 
laws that require the use of best management practices, such as leaving 
a riparian buffer, when clearing or building near a stream (Factor D). 
In Tennessee, any waterway with a State-listed species is designated an 
``Exceptional Tennessee Waterway,'' and projects impacting these 
streams are required to undergo additional review before receiving the 
necessary State permits. While agriculture is typically exempt from 
many of the provisions in State laws, various efforts described above, 
such as those in the Paint Rock River and South Chickamauga Creek, are 
working to reduce the impact of sedimentation from agriculture on the 
snail darter. Additionally, the snail darter's range overlaps with the 
ranges of more than 10 federally endangered mussels. This provides some 
protection, as entities implementing projects with a Federal nexus, 
such as infrastructure repair and construction and dam operation, are 
required to consult with the Service to reduce the impacts to listed 
species and designated critical habitat. These consultations may result 
in changes to the project to reduce sedimentation or limit the time of 
year when construction can take place to reduce disruption to the life 
history of a species. The protection, restoration, conservation, and 
management of ecological resources within the snail darter's range have 
been broadly enhanced through Executive orders and Federal regulations 
since the species was listed. These include provisions emphasizing the 
protection and restoration of ecosystem function and quality in 
compliance with existing Federal environmental statutes and regulations 
(e.g., National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.) 
and Clean Water Act (CWA; 33 U.S.C. 1251 et seq.)) and endorsing 
Federal efforts to advance environmental goals. Recent water resources 
authorizations have also enhanced opportunities for the involvement of 
the U.S. Army Corps of Engineers and other Federal agencies in studies 
and projects to specifically address objectives related to the 
restoration of ecological resources (e.g., section 1135 of the Water 
Resources Development Act of 1986, as amended, 33 U.S.C. 2201 et seq.).
    Protections associated with the CWA and State wildlife laws will 
continue to provide some protection to the snail darter. The fear that 
the species' notoriety would result in increased collection or other 
forms of take has not been realized since we reclassified the species 
to threatened, and collection is unlikely to have a major impact on 
species resilience in the foreseeable future. Additionally, even if 
range States were to cease protecting the snail darter, its wide range 
and current redundancy should minimize its risk of extinction for the 
foreseeable future.
    In addition to the threats mentioned in the downlisting rule (49 FR 
27510; July 5, 1984) that are addressed above, we now consider other 
threats or stressors that reasonably could affect the snail darter in 
the foreseeable future. One such potential threat is climate change. In 
the southeastern United States, clear trends in climate predictions are 
limited. However, annual temperatures are projected to increase; cold 
days will become less frequent; the freeze-free season will lengthen by 
up to a month; temperatures exceeding 95 degrees Fahrenheit ([deg]F) 
(35 degrees Celsius ([deg]C)) will increase; heat waves will become 
longer; and the number of category 5 hurricanes will increase (Ingram 
et al. 2013, p. 32). Variability in weather is predicted to increase, 
resulting in more frequent and more extreme dry years and wet years 
over the next century, with limited evidence of a directional 
precipitation trend anticipated in the Tennessee River Valley 
(Mulholland et al. 1997, pp. 951-955; Ingram et al. 2013, pp. 15, 35). 
One study (Jones et al. 2015, entire) did find a small, statistically 
significant negative trend indicating precipitation had decreased 
between 1950 and 2009 in a parts of the Upper Tennessee River Valley, 
but overall the trends during this time period were mixed.
    There is some evidence that the increased variability may already 
be taking effect. The two wettest years on record for the Tennessee 
River Valley (Simmons 2020, unpublished data) are 2018 and 2019. During 
the late summer and early fall of 2019, the second wettest year 
overall, parts of the Valley temporarily experienced abnormally dry or 
drought conditions (USDA Drought Monitor for Tennessee River Valley, 
October 1, 2019).
    Increased rainfall will result in increased runoff, higher river 
levels, and longer periods of spilling from the top of dams by TVA. 
During periods of spilling at dams, there is the chance for more 
oxygenation of tailwaters and temperature mixing that could benefit the 
snail darter. However, increased rainfall, especially extreme events, 
would increase runoff of sediment and pollutants into tributaries and 
eventually into the mainstem. These inputs could potentially degrade 
spawning and foraging habitat for the snail darter. Increased flows 
during the spawning season could also increase the distance that the 
pelagic larvae of snail darters drift before becoming benthic. If the 
larvae found suitable habitat, increased flow could expand the range of 
the species and contribute to genetic mixing; however, there is also 
the chance that larvae could be pushed into unsuitable habitat which 
would result in reduced survival. Drought would most likely impact the 
shallower habitats inhabited by snail darters in tributaries. The area 
of shoal habitat available during periods of low flow could be reduced 
during a drought. The flows could be further reduced by water 
extraction for irrigation. These reductions of spawning habitat could 
result in lower spawning success. If discharge is reduced enough, the 
clean-swept gravel habitats that the snail darter relies on in the 
mainstem could begin to retain silt, reducing habitat quality.
    There is evidence that the habitat and life history of the snail 
darter will protect it from predicted changes in climate over the next 
30 years. In a 2017 climate change vulnerability assessment of 700 
species, the Appalachian Landscape Conservation Cooperative (LCC) 
ranked the snail darter as ``presumed stable'' through 2050 under 
predicted climate conditions (Appalachian LCC 2017, supplemental data). 
Being adapted to large river habitats, the snail darter is less 
susceptible to impacts from high-flow events. As much of its habitat in 
the mainstem is already impounded, the effects of high water are less 
meaningful, and TVA flood control efforts may offset some of the strong 
flow peaks associated with extreme rain events. The species' preference 
for deeper water habitats and late winter spawning period protects it 
from

[[Page 60310]]

drought. Deep water habitats are not impacted by droughts as 
drastically as shallow habitats. The RRIP in TVA tailwaters ensures 
availability of suitable water for the mainstem populations throughout 
the year despite the occurrence of drought. Drought is also unlikely to 
impact spawning events on shoals in tributaries because late winter and 
early spring are typically the wettest times of the year within the 
Tennessee River Valley. The snail darter is likely also protected from 
the projected temperature increases by adaptation to larger streams and 
the thermal buffering of the large reservoirs on the mainstem.
    If we examine current projections beyond our 30-year foreseeable 
future, under plausible future greenhouse gas concentrations termed 
representative concentration pathways (RCP), warming temperatures and 
precipitation projections continue to suggest mixed effects to the 
species. Relative to 1981-2010, over 2050-2074, the 50th percentile 
(median) for the Tennessee Region, maximum air temperature warms by 4.4 
[deg]F (2.4 [deg]C) in RCP 4.5, whereas the region warms by 6.4 [deg]F 
(3.6 [deg]C) in RCP 8.5 (Alder and Hostetler 2013, entire). Changes in 
precipitation are not as apparent. Relative to 1981-2010, over 2050-
2074, the 50th percentile (median) for the Tennessee Region, 
precipitation increases by only 0.2 in (5.1 mm) per month in both RCP 
4.5 and RCP 8.5 (Alder and Hostetler 2013, entire). We still consider 
2050 as the foreseeable future timeline for this species because the 
time frame associated with the RRIP and other stressors have the 
greatest predictability between now and 2050, which allows us to draw 
stronger conclusions regarding the species response and condition. 
Additionally, we have greater certainty about the snail darters' 
response to changing climactic conditions between now and 2050 because 
we have both the projections and scientific sources that predict the 
species' response, such as the LCC report. Further, the climate 
projections are more reliable between now and 2050 as compared to 
beyond 2050 because the models diverge significantly after 2050, which 
results in substantial uncertainty regarding how changes in climate 
will manifest late-century. As a result, we do not consider the snail 
darter to be vulnerable to the effects of climate change in the 
foreseeable future.
    The increases documented in the abundance and distribution of the 
snail darter since it was listed in 1975 have led to a better 
understanding of the current and future condition of the species' 
resiliency, redundancy, and representation across the range. The 
observed variations in population size, density, or distribution of the 
snail darter are typical of metapopulation dynamics. Surveys have shown 
that individual populations may decline based on localized stressors 
(e.g., severe sedimentation, toxic spills, streamflow alteration) or 
their cumulative effects. When threats occur together, one may 
exacerbate the effects of another, causing effects not accounted for 
when threats are analyzed individually. However, the best available 
information does not demonstrate that cumulative effects are occurring 
at a level sufficient to negatively affect the species now nor do we 
anticipate that they will in the future.

Summary of Comments and Recommendations

    In the proposed rule published in the Federal Register on September 
1, 2021 (86 FR 48953), we requested that all interested parties submit 
written comments on our proposal to delist the snail darter by November 
1, 2021. We also contacted appropriate Federal and State agencies, 
scientific experts and organizations, and other interested parties and 
invited them to comment on the proposal. We did not receive any 
requests for a public hearing. All substantive information provided 
during the comment period has either been incorporated directly into 
this final rule or is addressed below.
    During the comment period, we received comments from 31 individuals 
addressing the proposed rule, representing 30 public commenters and 1 
partner review. Public comments are posted at https://www.regulations.gov under Docket No. FWS-R4-ES-2020-0152. Nine public 
commenters supported the proposed rule with no additional analysis or 
revision requested. These comments are not further addressed. Public 
comments that did not provide substantive information that could be 
evaluated or incorporated are also not addressed further. Several 
public commenters provided substantive information that is addressed 
below.

Public Comments

    (1) Comment: Several commenters expressed concern that the RRIP, 
which has been important in improving conditions in the TVA tailwaters, 
will not be continued if the snail darter is delisted. A few commenters 
also raised the concern of maintaining tailwater conditions in the 
event of TVA privatization.
    Our Response: Much of the snail darter's recovery in the mainstem 
Tennessee River can likely be tied to the implementation of the RRIP, 
which is a suite of dam management practices that results in increased 
oxygen and more stable temperatures and flow rates in the tailwaters of 
TVA dams. However, as noted above in Summary of Factors Affecting the 
Species, the tailwaters inhabited by snail darters are also home to 
between 8 and 20 Federally listed mussel species that also require 
consistent flows and oxygen below TVA dams. The presence of these 
listed species requires that TVA continue to provide suitable 
conditions for them in the operation of their dams under the existing 
EIS and Operations and Management biological opinion. It is also very 
likely that their presence will necessitate continuation of the RRIP 
into the future if the biological opinion is revisited. Therefore, we 
do not expect the management practices at the dams to change based on 
the delisting of the snail darter; we expect that conditions maintained 
for other listed species will continue to be suitable for survival of 
snail darters. If management conditions are determined to endanger or 
threaten the long-term viability of the snail darter such that it meets 
the Act's definition of an endangered or threatened species, we can use 
our authorities under section 4 the Act, including the emergency 
listing authorities at section 4(b)(7), to relist the species as 
appropriate.
    TVA is a public corporation within the Federal Government, but 
there have been considerations to convert it to a nongovernmental 
corporation. If TVA is privatized, the operation of the dams in the 
Tennessee Valley would no longer be directly managed by a Federal 
agency subject to the requirements of section 7 of the Act; however, 
the new corporation would still be regulated by the Federal Energy 
Regulatory Commission (FERC), which is also required to consult with 
the Service under section 7 of the Act to determine if their actions 
may affect any listed species. With the presence of federally listed 
mussels in the tailwaters, these consultations are unlikely to result 
in changes to operations that would negatively affect the tailwater 
conditions for the snail darter.
    (2) Comment: Some commenters expressed concern that 5 years of 
post-delisting monitoring was not enough to ensure continued viability 
of the snail darter and recommended that resources for genetic 
monitoring are needed to ensure maintenance of genetic diversity.
    Our Response: Following delisting, the Act requires the Service to 
work with States and other partners to prepare and implement a 
monitoring plan for the snail darter for at least 5

[[Page 60311]]

years following the delisting. We have developed a draft post-delisting 
monitoring plan for the snail darter in coordination with State and 
Federal agencies. The draft post-delisting monitoring plan is based on 
TVA's stream IBI monitoring and continuation of the reservoir trawl 
surveys for the snail darter. This plan will provide data on the 
continued resilience of the species or highlight unexpected declines 
and additional threats, should they arise. Five years of post-delisting 
monitoring of snail darters is sufficient because it will add to survey 
data collected over the past 10 years, which will allow us to look at 
the progress of the species over a longer time. Following 5 years of 
post-delisting monitoring, TVA will continue to monitor the health of 
the watersheds where snail darter is found by conducting IBI surveys. 
These surveys are expected to detect future declines of the species, 
should they occur. The draft post-delisting monitoring plan can be 
found at https://www.regulations.gov under Docket No. FWS-R4-ES-2020-
0152.
    We acknowledge that sustaining post-delisting monitoring efforts 
can be challenging and subject to competing priorities for available 
resources given that the Service cannot directly fund monitoring after 
a species has been delisted. Nonetheless, we designed a draft post-
delisting monitoring plan that is realistic given limited resources. 
While maintaining genetic diversity is important for species 
conservation, we were able to make the decision that the snail darter 
no longer meets the Act's definition of an endangered or threatened 
species without available genetic information. Similarly, we will be 
able to assess the viability of the snail darter in the future without 
genetic monitoring to determine if the species should be relisted.
    (3) Comment: A few commenters expressed concern that delisting the 
snail darter without complete population genetics for the species and 
without knowing the status of the newly discovered populations as 
distinct or descended from the translocated populations is premature.
    Our Response: We are required to make our determinations based on 
the best available scientific and commercial data at the time the 
determination is made. A need for further research on a species is not 
necessarily relevant to the question of whether the species meets the 
Act's definition of an endangered or threatened species. The presence 
of resilient populations in 10 tributaries and 7 mainstem reservoirs 
across four physiographic regions provides sufficient evidence of high 
redundancy and representation for the species. This abundance and 
distribution of self-sustaining snail darter populations in both 
tributaries and mainstem reservoirs led us to conclude that the snail 
darter does not meet the Act's definition of an endangered or 
threatened species. Furthermore, delisting does not prevent continued 
research on the species.
    While much of the success of the snail darter has come from the 
transplantation efforts into the Hiwassee and Holston Rivers, at the 
same time as those efforts, populations were found in Sewee Creek, 
South Chickamauga Creek, and in Nickajack Reservoir below Chickamauga 
Dam and near the mouth of the Sequatchie River. These discoveries 
indicate that the snail darter is wider spread than just the lower 
Little Tennessee River and that the recently discovered populations 
could have been established from multiple sources.
    (4) Comment: Several commenters raised concerns with the long-term 
impacts of climate change on the snail darter, and one commenter cited 
a climate study of the upper Tennessee River Basin that we had not 
considered in the proposed rule (Jones et al. 2015).
    Our Response: In the proposed rule (86 FR 48953; September 1, 
2021), we considered multiple climate models for the Tennessee Valley, 
including the RCP 4.5 and RCP 8.5 models (Alder and Hostetler 2013, 
entire), interior Southeast models (Mulholland et al. 1997, entire; 
Ingram et al. 2013, entire), as well as a meta-analysis potential 
climate vulnerability of 700 species of rare and imperiled Appalachian 
flora and fauna (Appalachian LCC, 2017). While there was some 
variability in the exact predictions, these studies provided evidence 
for limited changes from the mean in both temperature and precipitation 
before 2050, but that there would be more extreme events, such as 
floods and droughts. However, due to the snail darter's larger stream 
habitats, it is more resilient to these changes than would be a 
headwater or shallow habitat species. We also concluded that the RRIP 
would likely further buffer the effects of climate change in the 
tailwaters.
    The climate study from Jones et al. (2015) used past precipitation 
data for the upper Tennessee Valley to investigate trends between 1950 
and 2009, with a more complete TVA dataset for 1990-2010. These data 
suggested a small but statistically significant decrease in annual 
precipitation for most of the subwatersheds investigated, seasonal 
variation with increased precipitation in the drier months and a 
decrease in the wetter months. However, using the same TVA dataset, 3 
of the wettest years on record for the Tennessee Valley were in the 
last 5 years. While we anticipate the changes to precipitation from 
climate change to be noticeable in the foreseeable future, as mentioned 
above, the available evidence suggests that the snail darter will be 
resilient to these changes. We have incorporated information from Jones 
et al. (2015) and our analysis provided under Summary of Factors 
Affecting the Species, above.

Determination of the Snail Darter's Status

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species meets the definition of an endangered species or a 
threatened species. The Act defines an ``endangered species'' as a 
species that is in danger of extinction throughout all or a significant 
portion of its range, and a ``threatened species'' as a species that is 
likely to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range. For a more 
detailed discussion on the factors considered when determining whether 
a species meets the definition of an endangered species or a threatened 
species and our analysis on how we determine the foreseeable future in 
making these decisions, see Regulatory and Analytical Framework, above.

Status Throughout All of Its Range

    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we have found that snail darter representation and redundancy 
has increased, with extant populations in 7 mainstem reservoirs of the 
Tennessee River and 10 tributaries in the Tennessee River watershed. Of 
the mainstem reservoirs, six populations showed multiple age classes, 
and for these six, we have observed direct evidence of reproduction in 
three populations, indicating moderate or high resilience. Collection 
efforts in two mainstem reservoirs, Wilson and Kentucky reservoirs, 
failed to find snail darters during our analysis period. Of the 
tributaries, nine populations demonstrated moderate to high resilience; 
one population is considered to have low resilience with no evidence of 
reproduction; three tributary populations (Citico Creek, Flint River, 
and Shoal Creek) lacked sufficient collections during our analysis 
period to consider them established. Additionally, the species is now 
known to be present in four physiographic

[[Page 60312]]

regions indicating increased representation, and the multiple resilient 
populations indicate an increase in redundancy since the species was 
reclassified to threatened in 1984. Because the snail darter has 
increased in representation and redundancy generally, and in particular 
with respect to numbers of resilient, self-sustaining populations, we 
expect this species to be able to sustain populations into the 
foreseeable future.
    We have carefully assessed the best scientific and commercial 
information regarding the threats faced by the snail darter in 
developing this rule. Threats related to habitat loss and curtailment 
of range (Factor A) reported at the time of listing in 1975 (40 FR 
47505; October 9, 1975) and when we downlisted the species to 
threatened status in 1984 (49 FR 27510; July 5, 1984) have been reduced 
in many locations. Available data indicate the species possesses 
greater resilience to the negative effects of dams than was determined 
at the time of listing. Further, beneficial dam operations (i.e., RRIP) 
are expected to continue into the foreseeable future.
    At the time of the downlisting rule (49 FR 27510; July 5, 1984), it 
was thought that the notoriety of the snail darter would result in an 
increase in illegal collection (Factor B); however, no such activities 
have been seen, and we do not consider this a threat to the current or 
future viability of the species. State water quality and wildlife laws 
provide some protections to the snail darter and its habitat, and its 
range overlaps with other federally protected aquatic animals (Factor 
D). In addition, we have evaluated potential effects of climate change 
(Factor E) and the evidence indicates that the species is resilient to 
the predicted levels of climate change. Thus, after assessing the best 
available information, we conclude that the snail darter is not in 
danger of extinction or likely to become so throughout all of its range 
within the foreseeable future.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. Having determined that the snail darter is not in danger of 
extinction or likely to become so throughout all of its range in the 
foreseeable future, we now consider whether it may be in danger of 
extinction or likely to become so in the foreseeable future in a 
significant portion of its range--that is, whether there is any portion 
of the species' range for which it is true that both (1) the portion is 
significant; and (2) the species is in danger of extinction now or 
likely to become so in the foreseeable future in that portion. 
Depending on the case, it might be more efficient for us to address the 
``significance'' question or the ``status'' question first. We can 
choose to address either question first. Regardless of which question 
we address first, if we reach a negative answer with respect to the 
first question that we address, we do not need to evaluate the other 
question for that portion of the species' range.
    In undertaking this analysis for the snail darter, we choose to 
address the status question first--we consider information pertaining 
to the geographic distribution of both the species and the threats that 
the species faces to identify any portions of the range where the 
species may be endangered or threatened. For the snail darter, we 
considered whether the threats are geographically concentrated in any 
portion of the species' range on a biologically meaningful scale. We 
examined the following threats: habitat modification, curtailment of 
range, climate change, and illegal collection, including cumulative 
effects.
    Threats related to habitat modification or curtailment of range 
affect snail darters throughout their range. With the implementation of 
TVA's RRIP, conditions around the large dams on the mainstem of the 
Tennessee River have improved. Our analysis of the species' resiliency 
(see Analytical Framework, above), which integrated information on 
demographics and threats, determined that six of the nine reservoir 
populations showed multiple age classes and direct evidence of 
reproduction in three of the reservoirs. These reservoirs with 
resilient populations are distributed across the snail darter's range 
and multiple geographic provinces. Of the 10 resilient tributary 
populations, 9 populations demonstrated moderate to high resiliency. In 
tributary watersheds such as the Ocoee and Sequatchie where water 
quality was impacted by localized mining threats, conditions have 
improved due in part to the cessation of mining and efforts to clean up 
the mine sites. In watersheds with higher levels of agriculture and 
urbanization such as the South Chickamauga Creek and Paint Rock River 
watersheds, conservation programs are in place to reduce the impact of 
these activities on the instream habitat used by the snail darter. 
Based on the distribution of resilient populations and the conservation 
efforts put in place, we have determined that there are not any 
portions of the range where the species may be endangered or threatened 
due to habitat modification or curtailment of the range.
    We have reviewed other potential threats, including climate change, 
illegal collection, and cumulative effects, and concluded that there 
are not any portions of the range where the species is endangered or 
threatened due to these threats. Therefore, no portion of the species' 
range provides a basis for determining that the species is in danger of 
extinction now or likely to become so in the foreseeable future in a 
significant portion of its range. This does not conflict with the 
courts' holdings in Desert Survivors v. U.S. Department of the 
Interior, 321 F. Supp. 3d 1011, 1070-74 (N.D. Cal. 2018) and Center for 
Biological Diversity v. Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 
2017) because, in reaching this conclusion, we did not need to consider 
whether any portions are significant; and, therefore, we did not apply 
the aspects of the definition of ``significant'' in the Final Policy on 
Interpretation of the Phrase ``Significant Portion of Its Range'' in 
the Endangered Species Act's Definitions of ``Endangered Species'' and 
``Threatened Species'' (79 FR 37578; July 1, 2014) that court decisions 
held were invalid.

Determination of Status

    Our review of the best scientific and commercial data available 
indicates that the snail darter does not meet the definition of an 
endangered species or a threatened species in accordance with sections 
3(6) and 3(20) of the Act. In accordance with our regulations at 50 CFR 
424.11(d)(2), the snail darter has recovered. With this rule, we remove 
the snail darter from the List of Endangered and Threatened Wildlife.

Effects of This Rule

    This final rule revises 50 CFR 17.11(h) by removing the snail 
darter from the Federal List of Endangered and Threatened Wildlife. On 
the effective date of this rule (see DATES, above), the prohibitions 
and conservation measures provided by the Act will no longer apply to 
the snail darter. Federal agencies will no longer be required to 
consult with the Service under section 7 of the Act in the event that 
activities they authorize, fund, or carry out may affect the snail 
darter. There is no critical habitat designated for this species, so 
there will be no effect to 50 CFR 17.95.

Post-Delisting Monitoring

    Section 4(g)(1) of the Act requires us to implement a monitoring 
program for not less than 5 years for all species that have been 
delisted due to recovery.

[[Page 60313]]

Post-delisting monitoring refers to activities undertaken to verify 
that a species delisted due to recovery remains secure from the risk of 
extinction after the protections of the Act no longer apply. The 
primary goal of post-delisting monitoring is to ensure that the 
species' status does not deteriorate and that if a decline is detected, 
measures are taken to halt the decline so as to avoid the need to 
propose listing of the species again. If at any time during the 
monitoring period data indicate that protective status under the Act 
should be reinstated, we can initiate listing procedures, including, if 
appropriate, emergency listing under section 4(b)(7) of the Act. 
Section 4(g) of the Act explicitly requires us to cooperate with the 
States in development and implementation of post-delisting monitoring 
programs, but we remain responsible for compliance with section 4(g) 
and, therefore, must remain actively engaged in all phases of post-
delisting monitoring. We also seek active participation of other 
entities that are expected to assume responsibilities for the species' 
conservation post-delisting.

Post-Delisting Monitoring Overview

    A post-delisting monitoring plan was developed in partnership with 
State and Federal agencies. The post-delisting monitoring has been 
designed to verify that the snail darter remains secure from risk of 
extinction after its removal from the Federal List of Endangered and 
Threatened Wildlife by detecting changes in population trends. The Act 
has a minimum post-delisting monitoring requirement of 5 years; 
however, if populations decline in abundance past the defined threshold 
in the post-delisting monitoring plan or a substantial new threat 
arises, post-delisting monitoring may be extended or modified, and the 
status of the species will be reevaluated.
    Post-delisting monitoring will occur for 5 years with the first 
year of monitoring beginning after the publication of the final 
delisting rule. Post-delisting monitoring will be accomplished by using 
TVA's stream IBI monitoring to assess the resilience of tributary 
populations. Sites will be surveyed at least once within the 5-year 
period, though most will be surveyed two or three times. Reservoir 
trawl surveys will also be conducted, and all reservoirs will be 
surveyed at least three times during the post-delisting monitoring 
period to ensure the continued resilience and recruitment in the 
mainstem populations. A draft post-delisting monitoring plan for the 
species can be found at https://www.regulations.gov under Docket No. 
FWS-R4-ES-2020-0152. We will work closely with our partners to maintain 
the recovered status of the snail darter and ensure post-delisting 
monitoring is conducted and future management strategies are 
implemented (as necessary) to benefit the species.

Required Determinations

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

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

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. There are no Tribal lands associated 
with this final rule, and we did not receive any comments from any 
Tribes or Tribal members on the proposed rule (86 FR 48953; September 
1, 2021).

References Cited

    A complete list of all references cited in this final rule is 
available on the internet at https://www.regulations.gov under Docket 
No. FWS-R4-ES-2020-0152, or upon request from the Tennessee Ecological 
Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authors

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

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

    Accordingly, we hereby amend part 17, subchapter B of chapter I, 
title 50 of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless 
otherwise noted.


Sec.  17.11  [Amended]

0
2. In Sec.  17.11, at paragraph (h), amend the List of Endangered and 
Threatened Wildlife by removing the entry for ``Darter, snail'' under 
FISHES.

Martha Williams
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2022-21579 Filed 10-4-22; 8:45 am]
BILLING CODE 4333-15-P