Endangered and Threatened Wildlife and Plants; Reclassification of the Relict Darter From Endangered to Threatened With a Section 4(d) Rule, 66280-66296 [2023-20945]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 88, Number 186 (Wednesday, September 27, 2023)]
[Rules and Regulations]
[Pages 66280-66296]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-20945]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2021-0093; FF09E22000 FXES1113090FEDR 234]
RIN 1018-BF56


Endangered and Threatened Wildlife and Plants; Reclassification 
of the Relict Darter From Endangered to Threatened With a Section 4(d) 
Rule

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), reclassify 
the relict darter (Etheostoma chienense) from endangered to threatened 
under the Endangered Species Act of 1973 (Act), as amended. The relict 
darter is a fish species that occupies the Bayou de Chien stream system 
in western Kentucky. This action is based on a thorough review of the 
best available scientific and commercial information, which indicates 
that relict darter is not currently in danger of extinction throughout 
all or a significant portion of its range, but it is still likely to 
become so in the foreseeable future. We are also finalizing a rule 
under section 4(d) of the Act that provides for the conservation of the 
relict darter.

DATES: This rule is effective October 27, 2023.

ADDRESSES: Public comments and materials we received, as well as 
supporting documentation we used in preparing this rule, are available 
for public inspection at https://www.regulations.gov at Docket No. FWS-
R4-ES-2021-0093.

FOR FURTHER INFORMATION CONTACT: Lee Andrews, Field Supervisor, U.S. 
Fish and Wildlife Service, Kentucky Ecological Services Field Office, 
330 West Broadway, Suite 265, Frankfort, KY 40601; telephone 502-695-
0468. 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 warrants 
reclassification from endangered to threatened if it no longer meets 
the definition of endangered (in danger of extinction throughout all or 
a significant portion of its range). We are reclassifying the relict 
darter as a threatened species (i.e., ``downlisting'' the species) 
because we have determined it is not currently in danger of extinction. 
Reclassifying a species under the Act can only be accomplished by 
issuing a rule through the Administrative Procedure Act rulemaking 
process (5 U.S.C. 551 et seq.).
    What this document does. This rule reclassifies relict darter from 
an endangered species to a threatened species on the Federal List of 
Endangered and Threatened Wildlife (List), with a rule issued under 
section 4(d) of the Act, based on the species' current status, which 
has been improved through implementation of conservation actions.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. Based on the status review, the current threats 
analysis, and evaluation of conservation measures, we conclude that the 
relict darter no longer meets the Act's definition of an endangered 
species and should be reclassified to a threatened species. The species 
is no longer in danger of extinction throughout all or a significant 
portion of its range but is likely to become so within the foreseeable 
future.
    We have determined that the relict darter is a threatened species 
due to the following threats:
     Habitat destruction and modification caused by 
sedimentation, stream channelization, removal of riparian vegetation, 
drainage of riparian wetlands, and point and nonpoint source discharges 
(Factor A).
     Drought, accidental spills, and other potential 
catastrophic events (Factor E).
     Low genetic diversity resulting in reduced adaptive 
capacity and the inability to withstand stochastic disturbances (Factor 
E).
     Effects from climate change that are likely to exacerbate 
the impacts of drought, hurricanes, and flooding associated with storms 
and hurricanes in the future (Factor E).
    Section 4(d) rule. We are issuing a rule under the authority of 
section 4(d) of the Act (a ``4(d) rule'') for the relict darter. The 
4(d) rule specifically tailors the incidental take exceptions for the 
relict darter to provide protective mechanisms to State and Federal 
partners so that they may continue certain activities that are not 
anticipated to cause direct injury or mortality to the relict darter. 
These activities will facilitate the conservation and recovery of the 
species through routine enforcement, assisting sick or injured fish, 
and the active habitat management this species uniquely requires.

Previous Federal Actions

    Please refer to the proposed downlisting rule (87 FR 12056; March 
3, 2022) for a detailed description of previous Federal actions 
concerning the relict darter.

Summary of Changes From the Proposed Rule

    In preparing this final rule, we reviewed and fully considered all 
comments we received during the comment period from the peer reviewers 
and the public on the proposed rule to reclassify the relict darter. 
Minor, nonsubstantive changes and clarifications were made to the 
species status assessment (SSA) report and this document in response to 
comments. In preparing this final rule,

[[Page 66281]]

we also refined the Status Throughout a Significant Portion of Its 
Range analysis in order to better explain our determinations. However, 
the information we received during the peer review and public comment 
period on the proposed rule did not change our analysis, rationale, or 
determination for reclassifying the relict darter as a threatened 
species under the Act or for the 4(d) rule for the species.

Summary of Comments and Recommendations

    In the proposed rule published on March 3, 2022 (87 FR 12056), we 
requested that all interested parties submit written comments on the 
proposal by May 2, 2022. We also contacted appropriate Federal and 
State agencies, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. A 
newspaper notice inviting general public comment was published in the 
Paducah Sun on April 2, 2022. We did not receive any requests for a 
public hearing. All substantive information received during the comment 
period has either been incorporated directly into this final 
determination or is addressed below.

Peer Reviewer Comments

    As discussed in Supporting Documents below, we received comments 
from three peer reviewers. We reviewed all comments we received from 
the peer reviewers for substantive issues and new information regarding 
the information contained in the SSA report. The peer reviewers 
generally concurred with our methods and conclusions, and provided 
additional information, clarifications, and suggestions to improve the 
final SSA report. Peer reviewer comments are addressed in the following 
summary and were incorporated into the final SSA report as appropriate.
    (1) Comment: Two peer reviewers and one State partner reviewer 
suggested we revise the species' taxonomic discussion in chapter 2 of 
the SSA based on new information presented by Near et al. (2011).
    Our response: We incorporated the reference and modified the text 
to follow the phylogeny (classification) presented by Near et al. 
(2011). The relict darter is one of 11 recognized/valid species in the 
Etheostoma squamiceps complex (clade Stigmacerca).
    (2) Comment: One peer reviewer asked for clarification on whether 
the Little Bayou de Chien population was included in genetic analyses 
conducted by Kattawar and Piller (2020).
    Our response: Kattawar and Piller (2020) analyzed tissue samples 
from across the species' range, including the Little Bayou de Chien 
watershed. Their analyses demonstrated a panmictic population, where 
random mating occurs among all individuals in the Bayou de Chien 
watershed. We added clarifying text to the SSA report to reflect this 
information.
    (3) Comment: One peer reviewer asked if anything is known about the 
larval drift phase of the relict darter. They commented that similar 
species become benthic upon hatching, suggesting that the larval phase 
would have a low dispersal ability.
    Our response: Larval relict darters become benthic immediately 
after hatching, suggesting low dispersal ability for the larval stage 
(Shute 2020, pers. comm.). New text was added to the life-history 
diagram (figure 4) and table 1 of the SSA report.
    (4) Comment: One peer reviewer suggested that genetic drift would 
not be a significant threat to the relict darter due to the apparent 
panmictic population, as demonstrated by the genetic connectivity of 
the Little Bayou de Chien and Bayou de Chien populations (Kattawar and 
Piller 2020).
    Our response: We agree with the reviewer's comment about the relict 
darter's panmictic population, so we updated the SSA report and removed 
a discussion related to genetic drift and inbreeding depression as a 
threat to the relict darter. Despite the evidence of genetic 
connectivity, we suspect that the Little Bayou de Chien and Bayou de 
Chien populations have limited contemporary gene flow based on recent 
survey results and the presence of ecological barriers separating the 
two watersheds. Therefore, we retained a brief discussion of genetic 
isolation in the SSA report.
    (5) Comment: One peer reviewer asked if our estimate of the 
species' overall status would change if we recognized a single 
population (single management unit) versus the two populations 
described in the SSA report.
    Our response: Our interpretation of the species' status would not 
change under this scenario. If the Bayou de Chien and Little Bayou de 
Chien populations were combined in the SSA, we would be left with a 
single population with moderate resiliency. Due to its small size and 
limited occupancy, the Little Bayou de Chien population would 
contribute little to overall resiliency.
    (6) Comment: One reviewer suggested we mention the species' 
vulnerability to chemical spills in the Bayou de Chien watershed.
    Our response: We added additional text in chapter 4 (Water Quality 
Degradation) of the SSA report summarizing the species' vulnerability 
to chemical spills.
    (7) Comment: One peer reviewer suggested that we add a table 
summarizing all Kentucky Pollutant Discharge Elimination System (KPDES) 
violations in the Bayou de Chien watershed over the last 10 to 15 
years.
    Our response: In chapter 3 of the SSA report, we added table 3, 
which summarizes all current KPDES permits in the Bayou de Chien 
watershed. For one permittee, the City of Fulton Treatment Works, we 
also summarized all permit violations since 2010.

Public Comments

    (8) Comment: Two commenters stated that the reclassification is 
premature and untimely, indicating that relict darter is one of the 
rarest fishes in the United States, living in only five sites and with 
proof of reproduction in only one site. They stated that endemic 
species, due to their narrow geographical range are especially prone to 
extinction, indicating that habitat degradation and water quality 
impairment will impact the species in the future. They also indicated 
that small population size and little genetic variability put the 
species at risk of extinction.
    Our response: We acknowledge in our March 3, 2022, proposed rule 
(87 FR 12056) and in this final rule that the relict darter is 
naturally a narrow endemic species. We recognize that redundancy and 
representation may be inherently low for a narrow endemic like the 
relict darter. The fact that the species exhibits little genetic 
variation across its range and has a very low effective population size 
suggests a past population bottleneck (e.g., rangewide habitat 
disturbance) and subsequent genetic drift (loss of rare alleles in a 
small population). Its low species redundancy and representation are 
tempered by the moderate resiliency of the Bayou de Chien/Jackson Creek 
population, which has high relict darter abundance and evidence of 
continued reproduction. The increased population size and successful 
recruitment trends have improved based on surveys completed during the 
past decade and reduce the risk of extinction. Further, this moderately 
resilient population has survived threats, primarily because 
conservation efforts over the past three decades have improved and 
protected habitat within the system, thus enabling the breeding, 
feeding, and sheltering

[[Page 66282]]

needs of the relict darter to be met and sustaining the population over 
time.
    We also acknowledge that habitat loss and degradation through 
stream channel disturbance, removal of riparian vegetation, and 
pollution continue to affect the species, even though conservation 
actions over the past three decades have led to improved habitat 
conditions in portions of the Bayou de Chien mainstem and Jackson 
Creek, contributing to moderate resiliency for the larger population. 
The relict darter has benefited from protection as an endangered 
species under the Act and from improvements in water quality and 
habitat conditions stemming from both national and Kentucky statutes 
and regulations. However, these regulations have not prevented the 
degradation of some habitats used by the species. The primary threats 
that are currently acting on the species are expected to continue into 
the future, climate change is expected to exacerbate existing threats, 
and the species' low redundancy and low representation put the species 
at risk of extinction throughout all of its range in the foreseeable 
future. Thus, after assessing the best available information, we 
conclude that the relict darter is not currently in danger of 
extinction, but it is likely to become in danger of extinction within 
the foreseeable future throughout all of its range, consistent with a 
reclassification from endangered to threatened status under the Act.
    (9) Comment: One commenter stated that the future conditions model 
only predicts how future urbanization could impact habitat and did not 
account for other potential sources of habitat disturbance or water 
quality impairment, such as agriculture. The commenter stated that the 
focus should be to increase conservation efforts to minimize the chance 
of adverse changes to physical habitat from human activity.
    Our response: As detailed in the SSA report, we determined the rate 
of land cover change for each HUC 12 watershed encompassing relict 
darter populations using National Land Cover Database (NLCD) data. We 
also reviewed land cover change at the HUC 14 level in order to examine 
smaller watersheds such as Jackson Creek. Tables summarizing our land 
use analysis are provided in appendix E of the SSA report. The NLCD 
database considers land cover change that may result from a number of 
activities, including urban development, forestry, and agriculture. 
Between 2001-2011, total percent forest cover decreased by less than 1 
percent across all watersheds, while total percent agriculture (i.e., 
pasture/hay and cultivated crops) and development increased by less 
than 1 percent across all watersheds. For our future scenarios, we 
assumed the same rate of land cover change for Scenario 1 (continuation 
of current trend), a decrease in the rate of land cover change for 
Scenario 2, and an increase in the rate of land cover change for 
Scenario 3. Therefore, the future scenario analysis does encompass 
other sources of habitat disturbance and water quality impairment as 
indicated by land use change. Regarding conservation efforts, the Act 
requires Federal agencies to utilize their authorities to carry out 
conservation programs for the conservation of both threatened and 
endangered species. We recognize that future efforts are dependent on 
funding availability, available conservation opportunities, and the 
willing cooperation of our partners, so only a portion of actions may 
be undertaken in the future.

Supporting Documents

    An SSA team prepared an SSA report for the relict darter. The SSA 
team was composed of Service biologists, in consultation with other 
species experts. The SSA report represents a compilation of the best 
scientific and commercial data available concerning the status of the 
species, including the impacts of past, present, and future factors 
(both negative and beneficial) affecting the species.
    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 
2016, memorandum updating and clarifying the role of peer review of 
listing actions under the Act, we sought peer review of the SSA report. 
The Service sent the SSA report to three independent peer reviewers and 
received three responses. The purpose of peer review is to ensure that 
our reclassification determinations and 4(d) rules are based on 
scientifically sound data, assumptions, and analyses. The peer 
reviewers have expertise in the biology, habitat, and threats to the 
species.

I. Final Listing Determination

Background

    A thorough review of the relict darter's taxonomy, life history, 
and ecology is presented in the SSA report (Service 2020, pp. 8-15) and 
is summarized below.

Species Information

    The relict darter is a small, narrowly endemic, benthic fish that 
occupies the Bayou de Chien stream system in western Kentucky. It can 
be distinguished from other darters by the number of dorsal fin rays 
(bony or cartilaginous spines of first and second fins along top of 
body), its breeding behavior (egg-clustering with parental care), and 
the color and morphology of the dorsal fins of breeding males. Females 
and nonbreeding males have light-tan-colored backs and sides, with 
brown mottling and six to eight dark brown saddles. They have white, 
unmarked undersides. Breeding males have gray to dark brown sides and 
backs and light tan undersides (Page et al. 1992, p. 628).

Taxonomy

    The relict darter, Etheostoma chienense, is a member of the Class 
Actinopterygii (ray-finned fishes), Order Perciformes, Family Percidae 
(perches), and Tribe Etheostomatini (darters) (Etnier and Starnes 1993, 
pp. 18-25, 440-441). The relict darter was first discovered in the 
Bayou de Chien system in 1975 (Webb and Sisk 1975), reported as E. 
squamiceps, but it was not recognized as a distinct species and 
described until 1992.

Genetics

    A population bottleneck and subsequent genetic drift likely explain 
the species' low genetic diversity and low effective population size, 
which is estimated at a mean of 221.5 individuals, lower than what is 
usually sufficient (500) to retain a species' evolutionary potential 
(Soule 1980, pp. 151-169; Kattawar and Piller 2020, entire). 
Agricultural expansion within the Bayou de Chien system during the 
early to mid-20th century, including widespread channelization and 
straightening of stream channels, likely led to a sharp reduction in 
the size of the relict darter population. Populations have likely 
stabilized some over time, but the effects of a population bottleneck 
and subsequent genetic drift appears to have led to low levels of 
genetic diversity across the range. Recent field surveys (2010-2019) 
suggest that relict darters in Little Bayou de Chien are isolated from 
the rest of the system; however, genetic analyses indicate a single 
panmictic population, where random mating occurs among all individuals 
in the Bayou de Chien system (i.e., individuals can interbreed without 
restrictions) (Kattawar and Piller 2020, entire).

Distribution

    The relict darter's historical range included the Bayou de Chien 
stream system, a 554-square-kilometer (km\2\) (214-square-mile (mi\2\)) 
watershed located within the Mississippi Valley Loess Plains ecoregion 
(Woods et al. 2002, entire) in Fulton, Graves, and

[[Page 66283]]

Hickman Counties, Kentucky (Webb and Sisk 1975, entire; Warren et al. 
1994, entire; Piller and Burr 1998, entire). Bayou de Chien is a low-
gradient, sand, gravel, and silt-bottomed stream that begins in 
southwestern Graves County and flows westward approximately 47 km (29.2 
mi) through Hickman and Fulton Counties, before ultimately emptying 
into Obion Creek near Hickman, Kentucky. All but the terminal 8-10 km 
(5.0-6.2 mi) of Bayou de Chien have been subjected to extensive 
channelization, and the dominant land use is row-crop agriculture (Webb 
and Sisk 1975, p. 63). Currently, the relict darter continues to occupy 
portions of the Bayou de Chien system in Fulton, Graves, and Hickman 
Counties, Kentucky. The species is represented by two geographically 
isolated populations: Bayou de Chien/Jackson Creek and Little Bayou de 
Chien (Service 2020, p. 20).

Habitat

    The species typically occupies slow-flowing runs, glides, or pools 
of small to medium-sized, lowland streams with sand and gravel 
substrates. In these habitats, the species is most commonly observed 
near cover, such as undercut banks, woody debris piles, or snags. An 
abundance of woody debris provides a sufficient supply of spawning 
substrates and, consequently, the highest mean densities of the species 
(Service 2020, p. 10).

Biology

    The species feeds primarily on midge larvae and other small 
invertebrates. Spawning occurs from mid-March to early June, and the 
species has a maximum lifespan of 3 to 4 years. Like all members of the 
Etheostoma squamiceps complex, females deposit eggs on the undersides 
of submerged objects, and egg clusters are guarded by the male until 
hatching occurs (Service 1994, p. 7). During a 1999 survey, most nests 
were located on natural materials such as small rocks, woody debris, 
and live tree roots, but 37 percent of nests were found on 
anthropogenic materials such as rubber tires, plastic, roof shingles, 
glass, concrete blocks, metal road signs, and concrete slabs (Piller 
and Burr 1998, pp. 147-151).
    The species was characterized as uncommon or rare at most 
collection sites in the 1990s, generally consisting of 1 to 23 
individuals per site (Piller and Burr 1998, pp. 66-71). Recent surveys 
indicate the species continues to be rare in some reaches but is more 
common in others. Generally, the greatest number of darters per 
sampling reach and the highest mean densities (0.43 darters/square 
meter) have been observed in Jackson Creek and an approximately 22.6-km 
(14.1-mi) reach of Bayou de Chien (0.30 darters/square meter), 
extending from just downstream of the U.S. 51 bridge crossing in 
Hickman County upstream to the Pea Ridge Road bridge crossing in Graves 
County (Service 2020, appendix A).

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and the implementing 
regulations in title 50 of the Code of Federal Regulations set forth 
the procedures for determining whether a species is an endangered 
species or a threatened species, issuing protective regulations for 
threatened species, and designating critical habitat for endangered and 
threatened species. In 2019, jointly with the National Marine Fisheries 
Service, the Service issued a final rule that revised the regulations 
in 50 CFR part 424 regarding how we add, remove, and reclassify 
endangered and threatened species and the criteria for designating 
listed species' critical habitat (84 FR 45020; August 27, 2019). On the 
same day, 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 (84 FR 44753; August 27, 2019). We collectively 
refer to these actions as 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. We consider these same five 
factors in downlisting a species from endangered to threatened.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the expected response by the species, 
and the effects of the threats--in light of those actions and 
conditions that will ameliorate the threats--on an individual, 
population, and species level. We evaluate each threat and its expected 
effects on the species, then analyze the cumulative effect of all of 
the threats on the species as a whole. We also consider the cumulative 
effect of the threats in light of those actions and conditions that 
will have positive effects on the species, such as any existing 
regulatory mechanisms or conservation efforts. The Secretary 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.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis. The term 
``foreseeable future'' extends only so far into the future as the 
Services can reasonably determine that both the future threats and the 
species' responses to those threats are likely. In other words, the 
foreseeable future is the period of time in which we can make reliable 
predictions. ``Reliable'' does not mean ``certain''; it means 
sufficient to

[[Page 66284]]

provide a reasonable degree of confidence in the prediction. Thus, a 
prediction is reliable if it is reasonable to depend on it when making 
decisions.
    It is not always possible or necessary to define the foreseeable 
future as a particular number of years. Analysis of the foreseeable 
future uses the best scientific and commercial data available and 
should consider the timeframes applicable to the relevant threats and 
to the species' likely responses to those threats in view of its life-
history characteristics. Data that are typically relevant to assessing 
the species' biological response include species-specific factors such 
as lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
threats to the species. The SSA report does not represent a decision by 
the Service on whether the species should be listed as an endangered or 
threatened species under the Act. It does, however, provide the 
scientific basis that informs our regulatory decisions, which involve 
the further application of standards within the Act and its 
implementing regulations and policies. The following is a summary of 
the key results and conclusions from the SSA report; the full SSA 
report can be found at https://www.regulations.gov at Docket No. FWS-
R4-ES-2021-0093.
    To assess relict darter viability, we used the three conservation 
biology principles of resiliency, redundancy, and representation 
(Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency reflects 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 changes). 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.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical 
and current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. Throughout all of these 
stages, we used the best available information to characterize 
viability as the ability of a species to sustain populations in the 
wild over time. We use this information to inform our regulatory 
decision.
    The following is a summary of the key results and conclusions from 
the SSA report; the full SSA report can be found at Docket No. FWS-R4-
ES-2021-0093 on https://www.regulations.gov.

Summary of Biological Status and Threats

    In this discussion, we review the biological condition of the 
species and its resources, and the threats that influence the species' 
current and future condition, in order to assess the species' overall 
viability and the risks to that viability. In addition, the SSA 
(Service 2019, entire) documents our comprehensive biological status 
review for the species, including an assessment of the potential 
threats to the species. The following is a summary of this status 
review and the best available information gathered since that time that 
have informed this decision.

Factors Influencing Relict Darter Viability

    At the time of listing in 1993, the relict darter was known only 
from the Bayou de Chien mainstem and Jackson Creek, but it was later 
discovered in Little Bayou de Chien in 2017 (Service 2019, p. 11). 
Threats to the species at the time of listing were water quality and 
habitat deterioration resulting from stream channelization, siltation 
contributed by incompatible land use practices, and water pollutants 
from waste discharges. Relict darter distribution was reduced by these 
factors, and because the species was known to inhabit only limited 
areas and known to spawn in only one small tributary, it was deemed 
vulnerable to extirpation from toxic chemical spills (see 58 FR 68480; 
December 27, 1993). Additionally, because of its small population size, 
the species' long-term genetic viability was determined to be 
questionable at the time of listing.
    While the relict darter's viability has improved over time (see 
Conservation Efforts, below), three major factors are influencing the 
viability of the species now and are expected to affect it into the 
future: habitat loss and degradation, restricted range/isolation, and 
climate change. Habitat loss and degradation resulting from siltation, 
channelization/riparian vegetation removal, drainage of riparian 
wetlands, and water quality degradation (pollution) (Factor A) pose the 
largest risk to the current and future viability of the relict darter. 
Other potential stressors to the species are the restricted range of 
the species and climate change (Factor E). We find the species does not 
face threats from overutilization (Factor B), disease or predation 
(Factor C), or invasive species (Factor E). A brief summary of relevant 
stressors is presented below; for a full description, refer to chapter 
3 of the SSA report (Service 2020, entire).

Siltation

    Siltation is the process whereby excess sediments are suspended or 
deposited in a stream. Excessive levels of sediments accumulate and 
cover the stream bottom, filling the interstitial spaces with finer 
substrates and homogenizing and decreasing the available habitat for 
fishes. In severe cases, sediment can bury larger substrate particles 
such as gravel and cobble, as well as woody debris. Siltation can 
abrade or suffocate fish gills, eggs, and larvae; reduce disease 
tolerance; degrade or destroy spawning habitats, affecting egg, larval, 
and juvenile development; modify migration patterns; reduce food 
availability through the blockage of primary production; and reduce 
foraging efficiency (Berkman and Rabeni 1987, pp. 285-294; Waters 1995, 
pp. 5-7; Wood and Armitage 1997, pp. 211-212; Meyer and Sutherland 
2005, pp. 2-3). Thus, siltation is a threat to all life stages of the 
relict darter. In addition, relict darter spawning substrates are 
usually the undersides of fixed objects (e.g., wood, tree roots, 
cobble, tires), which are vulnerable to the effects of siltation (i.e., 
embeddedness, or being completely covered in sediment) (Service 2020, 
p. 14).
    Sediment (siltation) is one of the most common stressors of aquatic 
communities in the Bayou de Chien system (Kentucky Division of Water 
(KDOW) 2018, pp. 43-45). The primary sources of sediment are listed as 
agriculture (crop production) and habitat degradation (channel erosion/
incision from upstream

[[Page 66285]]

hydromodifications, dredging, and loss of riparian habitat). The Bayou 
de Chien system is extensively farmed (e.g., row crops and livestock), 
and a large portion of the system has been deforested. These land use 
practices result in a high silt load within the system that continues 
to degrade habitats and impact the species. Croplands have the 
potential to contribute large sediment loads during storm events, 
thereby causing increased siltation and potentially introducing harmful 
agricultural pollutants such as pesticides. Unrestricted livestock 
access to streams has the potential to cause siltation and other 
habitat disturbance (Fraley and Ahlstedt 2000, pp. 193-194). Grazing 
may reduce water infiltration rates and increase stormwater runoff; 
trampling and vegetation removal increase the probability of erosion 
and siltation (Brim Box and Mossa 1999, p. 103). Physical habitat 
disturbance from sedimentation is less common in Jackson Creek than in 
other portions of the Bayou de Chien system.
    Several streams within the Bayou de Chien system have been 
identified as impaired due to siltation and have been included by the 
State of Kentucky on its list of impaired waters required under section 
303(d) of the Clean Water Act (33 U.S.C. 1313(d)) (KDOW 2018, pp. 43-
45). Portions of several streams occupied by the relict darter are on 
this list, including Cane Creek (stream kilometers (km) 0-8.5 (stream 
miles (mi) 0-5.3)) in Hickman County, Little Bayou de Chien (stream km 
1.8-3.8 and 18.8-22.5 (stream mi 1.1-2.4 and 11.7-14.0)) in Fulton and 
Hickman Counties, and South Fork Bayou de Chien (stream km 0-12.6 
(stream mi 0-7.8)) in Graves County.

Channelization/Riparian Vegetation Removal

    Stream channelization is a common practice used to reduce the 
effects of flooding, increase the drainage rate of agricultural land, 
and maximize the amount of tillable land (Piller and Burr 1998, p. 65). 
These modified channels are often managed through vegetation removal 
and dredging to improve flood conveyance or through placement of 
quarried stone or gabion baskets to protect against bank erosion (Allan 
and Castillo 2007, p. 327).
    Historically, Bayou de Chien was presumably a free-flowing stream 
with alternating areas of riffles, runs, and pools. Since that time, 
many stream reaches within the system have been channelized and 
converted to deep ditches with uniform depth, velocity, and substrate 
(Piller and Burr 1998, p. 71). Channelization has impacted the Bayou de 
Chien system by changing stream flow patterns, including reducing 
instream flows (especially during drier periods) that stress relict 
darters; decreasing aquatic habitat complexity, which affects 
sheltering and feeding for relict darters; and reducing stream bank and 
floodplain (riparian) vegetation (Piller and Burr 1998, p. 71), which 
affects relict darter feeding and breeding resource needs. Channelized 
reaches have higher stream velocities and shear stress (a measure of 
the force of water against the channel boundary) during high flow 
periods (which leads to channel instability and bank erosion), less 
instream cover and habitat for aquatic organisms including the relict 
darter (decreased habitat complexity), less riparian vegetation and 
correspondingly reduced canopies (reduced shade and reduced woody 
debris input), and below normal flows during drier periods (Warren et 
al. 1994, p. 24; Piller and Burr 1998, p. 71). Thus, the relict darter 
is susceptible to impacts from channelization and reductions in 
riparian vegetation because these stressors affect flows, habitat 
complexity, and instream temperatures and reduce the amount of woody 
material, thus affecting sheltering and reproduction needs of the 
species.
    The reduction or loss of riparian vegetation contributes to 
siltation through bank destabilization and the removal of submerged 
root systems that help to hold sediments in place while providing 
habitat for relict darters and their macroinvertebrate prey (Barling 
and Moore 1994, p. 544; Beeson and Doyle 1995, p. 989; Allan 2004, p. 
262; Hauer and Lamberti 2006, pp. 721-723; Minshall and Rugenski 2006, 
pp. 721-723). Removal of riparian vegetation can also reduce the 
stream's capacity for trapping and removing contaminants and nutrients 
from runoff; increase solar exposure, resulting in higher water 
temperatures; increase algal abundance (primary production); and reduce 
inputs of woody debris and leaf litter, thereby reducing food sources 
for relict darters and lowering overall stream production (Brazier and 
Brown 1973, p. 4; Karr and Schlosser 1978, p. 231; Peterjohn and 
Correll 1984, p. 1473; Osborne and Kovacic 1993, p. 255; Barling and 
Moore 1994, p. 555; Vought et al. 1994, p. 346; Allan 1995, p. 109; 
Wallace et al. 1999, p. 429; Pusey and Arthington 2003, p. 4). Where a 
reduction or loss of riparian vegetation occurs, these impacts 
negatively affect the quality of habitat available to the relict darter 
for breeding, feeding, and sheltering.

Drainage of Riparian Wetlands

    With increased agricultural activity in the Bayou de Chien basin 
over the last century, much of the basin's vegetation has been cleared, 
and many riparian wetlands have been drained to make additional lands 
available for farming (Piller and Burr 1998, p. 65). This situation has 
caused an overall reduction in the groundwater level and base flows 
within Bayou de Chien and its tributaries. Many small streams in the 
system become completely dry or consist of isolated pools by the early 
fall months (Warren et al. 1994, p. 24). These conditions serve to 
isolate populations and subject both the adult and juvenile relict 
darters to increased pressure from predators (Service 1994, p. 14). 
Dispersal of the species upstream of the Jackson Creek area or into 
many downstream tributaries may be limited by instream flow conditions 
(Warren et al. 1994, p. 24).

Water Quality Degradation (Pollution)

    Information is lacking on the relict darter's tolerance to specific 
pollutants, but a variety of contaminants continue to degrade stream 
water quality within the Bayou de Chien system, and these pollutants 
may affect the relict darter. Several point-source and nonpoint-source 
pollutants to aquatic life occur in the Bayou de Chien system (Service 
2020, appendix B) (KDOW 2018, pp. 43-45). These pollutants include 
copper, iron, lead, excess nutrients (total nitrogen and phosphorus), 
and eutrophication originating from two suspected sources--municipal 
point source discharges (e.g., sewage treatment) and agriculture (e.g., 
crop production and animal feeding operations). Portions of four 
streams that are occupied by relict darter, specifically Bayou de 
Chien, Cane Creek, Little Bayou de Chien, and South Fork Bayou de 
Chien, were identified as impaired due to these pollutants (KDOW 2018, 
pp. 43-45). The impacts of copper, lead, and iron inputs are unknown, 
but nutrient inputs and eutrophication can lead to excessive algal 
growths and instream oxygen deficiencies that can seriously affect 
aquatic species, including the relict darter.
    Currently, 13 National Pollutant Discharge Elimination System 
permits have been issued authorizing the discharge of pollutants within 
portions of the Bayou de Chien system (Fredenberg 2018, pers. comm.; 
Service 2020, p. 27). Two sewage treatment plants, the City of Fulton 
Treatment Works (Kentucky Pollutant Discharge Elimination System 
(KPDES)

[[Page 66286]]

#KY0026913) and the Hickman East Sewage Treatment Plant (KPDES 
#KY0028436), discharge treated wastewater directly into Bayou de Chien. 
Between January 2010 and April 2020, the Fulton facility received 13 
violation notices from KDOW. The notices were issued for permit 
exceedances of a variety of chemical parameters (e.g., biochemical 
oxygen demand (BOD), total suspended solids (TSS), pH) and for failures 
to meet certain monitoring requirements associated with the permit 
(Service 2020, appendix C). Insufficient treatment of wastewater could 
harm relict darter populations by introducing pollutants (e.g., metals, 
bacteria) and altering water quality conditions (e.g., decreased oxygen 
levels, elevated pH).
    The Bayou de Chien system is also affected by nonpoint-source 
pollutants, arising from a variety of diffuse sources. Examples of 
nonpoint-source pollutants include sediment (e.g., stormwater runoff 
from driveways, fields, construction sites), raw sewage (e.g., septic 
tank leakage, straight pipe discharges), animal waste from livestock, 
fertilizers, pesticides, herbicides, and road salt (KDOW 2013, pp. 19-
21; KDOW 2018, pp. 43-45). Nonpoint-source pollutants can cause excess 
nutrification (increased levels of nitrogen and phosphorus), excessive 
algal growths that clog the waterway and affect swimming capability and 
visual predation, instream oxygen deficiencies that affect oxygen 
intake by relict darters, and other changes in water chemistry that can 
affect aquatic species such as the relict darter. Nonpoint-source 
pollution from land surface runoff can originate from virtually any 
land use activity and has been correlated with impervious surfaces and 
storm water runoff (Allan 2004, pp. 266-267). Pollutants may include 
sediments, fertilizers, herbicides, pesticides, animal wastes, septic 
tank and gray water leakage, pharmaceuticals, and petroleum products. 
These pollutants tend to increase concentrations of nutrients and 
toxins in the water and alter the chemistry of affected streams such 
that the habitat and food sources for species like the relict darter 
are negatively impacted.
    Due to its linear distribution within the Bayou de Chien mainstem 
and Jackson Creek, the relict darter continues to be vulnerable to 
accidental chemical or animal waste spills and releases that may result 
from traffic accidents, agricultural activities, or permitted 
discharges (Warren et al.1994, p. 24). Events of this kind have 
affected other aquatic communities in the southeastern United States 
during the recent past (Ahlstedt et al. 2016, pp. 8-9), so similar 
events have the potential to affect relict darter populations in the 
Bayou de Chien system. These events could have devastating effects on 
darters in these reaches (Piller and Burr 1996, p. 74) and could pose a 
threat to the long-term viability of the species.

Restricted Range/Isolation

    The relict darter has always had a limited geographic range, 
currently consisting of approximately 52.5 stream km (32.7 stream mi) 
within a single stream system in western Kentucky (Bayou de Chien 
system). The species was characterized as uncommon or rare at most 
collection sites in the 1990s (Piller and Burr 1998, pp. 66-71), and 
recent surveys indicate the species continues to be rare in some 
reaches but is more common in others.
    The species' restricted range and low abundance in some reaches 
(e.g., Little Bayou de Chien and Cane Creek) make it more vulnerable to 
extirpation from toxic chemical spills, habitat modification, 
degradation from land surface runoff (nonpoint-source pollution), and 
natural catastrophic changes to their habitat (e.g., flood scour, 
drought). In particular, recent survey data indicate that the relict 
darter's most successful reproduction occurs in Jackson Creek and 
middle and headwater reaches of Bayou de Chien, which are vulnerable to 
catastrophic events, such as a single toxic chemical spill or an 
extreme weather event such as a drought or flash flood. These events 
could have devastating effects on darters in these reaches (Piller and 
Burr 1996, p. 74) and could pose a threat to the long-term viability of 
the species.
    The relict darter is represented by two geographically isolated 
populations: Bayou de Chien/Jackson Creek and Little Bayou de Chien 
(Service 2020, p. 20). The fact that the Little Bayou de Chien 
population is small and isolated from the larger Bayou de Chien/Jackson 
Creek population makes it more vulnerable to stochastic and 
catastrophic events, thus affecting overall relict darter viability.

Climate Change

    Species that are dependent on specialized habitat types, limited in 
distribution, or at the extreme periphery of their range may be most 
susceptible to the impacts of climate change (Byers and Norris 2011, 
pp. 18-19); however, while continued change is certain, the magnitude 
and rate of change is unknown in many cases. Climate change has the 
potential to increase the vulnerability of the relict darter to random 
catastrophic events (McLaughlin et al. 2002, pp. 6060-6074; Thomas et 
al. 2004, pp. 145-148). An increase in both severity and variation in 
climate patterns is expected; extreme floods, strong storms, and 
droughts will become more common (Cook et al. 2004, pp. 1015-1018; Ford 
et al. 2011, p. 2065; Intergovernmental Panel on Climate Change 2014, 
pp. 58-83). Frequency, duration, and intensity of droughts are likely 
to increase in the Southeast as a result of global climate change 
(Thomas et al. 2004, pp. 145-148). Stream temperatures in the Southeast 
have increased roughly 0.2-0.4 degrees Celsius ([deg]C) (0.4-0.7 
degrees Fahrenheit ([deg]F)) per decade over the past 30 years, and as 
air temperature is a strong predictor of water temperature, stream 
temperatures are expected to continue to rise (Kaushal et al. 2010, p. 
465). Predicted impacts of climate change on fishes include disruption 
to their physiology (such as temperature tolerance, dissolved oxygen 
needs, and metabolic rates), life history (such as timing of 
reproduction, growth rate), and distribution (range shifts, migration 
of new predators) (Jackson and Mandrak 2002, pp. 89-98; Heino et al. 
2009, pp. 41-51; Strayer and Dudgeon 2010, pp. 350-351; Comte et al. 
2013, pp. 627-636).
    Estimates of the effects of climate change using available climate 
models typically lack the geographic precision needed to project the 
magnitude of effects at a scale small enough to discretely apply to the 
range of a given species. However, data on recent trends and projected 
changes for Kentucky (Girvetz et al. 2009, pp. 1-19), and, more 
specifically, the Bayou de Chien system (Alder and Hostetler 2017, 
entire) provide some insight for evaluating the potential impacts of 
climate change to the relict darter. Different emission scenarios have 
been used to calculate estimates of average annual increases in maximum 
and minimum air temperature, precipitation, snowfall, and other 
variables (Alder and Hostetler 2017, entire). These scenarios, called 
representative concentration pathways (RCPs), are plausible pathways 
toward reaching a target radiative forcing (the change in energy in the 
atmosphere due to greenhouse gases) by the year 2100 (Moss et al. 2010, 
p. 752). Depending on the chosen model and emission scenario (RCP 8.5 
(high) vs. 4.5 (moderate)), annual mean maximum air temperatures for 
the Bayou de Chien system are expected to increase by 2.3-3.4 [deg]C 
(4.1-6.1 [deg]F) by 2074, while precipitation models predict that the 
Bayou de Chien system

[[Page 66287]]

will experience a slight increase in annual mean precipitation (0.5 
centimeters/month (0.2 inches/month)) through 2074 (Girvetz et al. 
2009, pp. 1-19; Alder and Hostetler 2016, pp. 1-9).
    There is uncertainty about the specific effects of climate change 
(and their magnitude) on the relict darter; however, climate change is 
almost certain to affect aquatic habitats in the Bayou de Chien system 
of western Kentucky through increased water temperatures and more 
frequent droughts (Alder and Hostetler 2017, entire), and species with 
limited ranges, fragmented distributions, and small population size, 
such as the relict darter, are thought to be especially vulnerable to 
the effects of climate change (Byers and Norris 2011, pp. 18-19). Thus, 
we consider climate change to be a threat to the relict darter.

Regulatory Mechanisms

    The relict darter and its habitats are afforded some protection 
from water quality and habitat degradation under the Clean Water Act, 
Kentucky's Forest Conservation Act of 1998 (Kentucky Revised Statutes 
(KRS), chapter 149, sections 149.330-355), Kentucky's Agriculture Water 
Quality Act of 1994 (KRS, chapter 224, subchapter 71, sections 224.71-
100-224.71-140), and additional Kentucky statutes and regulations 
regarding natural resources and environmental protection (KRS, chapter 
224; title 401 of the Kentucky Administrative Regulations (KAR) at 
Chapters 10:026, 10:029, and 10:031). While it is clear that the 
protections afforded by these statutes and regulations have not 
prevented the degradation of some habitats used by the relict darter, 
the species has undoubtedly benefited from improvements in water 
quality and habitat conditions stemming from these regulatory 
mechanisms.

Conservation Efforts

    The relict darter is listed as endangered in Kentucky (OKNP 2019, 
p. 16), making it unlawful to take the species or damage its habitat 
without a State permit. Additionally, the relict darter is identified 
as a species of greatest conservation need in the Kentucky Wildlife 
Action Plan (KDFWR 2013, chapter 2), which outlines actions to promote 
species conservation.
    Since listing the species (see 58 FR 68480; December 27, 1993), the 
Service has worked with multiple agencies and private partners (e.g., 
the U.S. Department of Agriculture's Natural Resources Conservation 
Service (NRCS), the Kentucky Department of Fish and Wildlife Resources 
(KDFWR), and The Nature Conservancy (TNC)) to implement conservation 
actions for the relict darter in the Bayou de Chien system. The 
Service's Partners for Fish and Wildlife (PFW) program has taken the 
lead role in this effort by providing technical and financial 
assistance to agencies and numerous private landowners. PFW has focused 
its efforts on the use of best management practices (BMPs) and instream 
conservation practices that enhance and restore riparian and instream 
habitats used by the relict darter. PFW projects have included a 
culvert removal in the headwaters of Bayou de Chien, installation of 
livestock alternate watering systems, placement of artificial spawning 
structures in Bayou de Chien and Jackson Creek, installation of 
livestock exclusion fencing along several kilometers of Bayou de Chien 
and Jackson Creek, and restoration of more than 20.2 hectares (50 
acres) of native grasses and wildflowers within riparian areas. In 
addition to these efforts, PFW biologists have provided over 10 years 
of technical assistance to the U.S. Department of Agriculture, Wetland 
Reserve Easement Program, for projects within the Bayou de Chien system 
(Radomski 2019, pers. comm.). These efforts have resulted in permanent 
easements covering more than 1,700 acres (688 hectares) in the upper 
Bayou de Chien system (Morris 2020, pers. comm.). These easements will 
benefit the relict darter through sediment and nutrient reduction, 
shading of stream corridors (via riparian plantings), hydrological 
restoration (via plugging of agricultural ditches and improved 
groundwater connections), and general habitat creation or wetland 
restoration.

Synergistic and Cumulative Effects

    In addition to affecting the relict darter individually, it is 
possible that several of the risk factors summarized above are acting 
synergistically, and all act cumulatively on the species. The combined 
impact of multiple stressors is likely more harmful than a single 
stressor acting alone. The dual stressors of climate change and direct 
human impact have the potential to affect aquatic ecosystems by 
altering stream flows and nutrient cycles, eliminating habitats, and 
changing community structure (Moore et al. 1997, p. 942). Increased 
water temperatures and a reduction in stream flow are the climate 
change effects that are most likely to affect stream communities (Poff 
1992, entire; Thomas et al. 2004, pp. 145-148), and each variable is 
strongly influenced by land use patterns.
    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have not 
only analyzed individual effects on the species, but we have also 
analyzed their potential cumulative effects. We incorporate the 
cumulative effects into our SSA analysis when we characterize the 
current and future condition of the species. To assess the current and 
future condition of the species, we undertake an iterative analysis 
that encompasses and incorporates the threats individually and then 
accumulates and evaluates the effects of all the factors that may be 
influencing the species, including threats and conservation efforts. 
Because the SSA framework considers not just the presence of the 
factors, but to what degree they collectively influence risk to the 
entire species, our assessment integrates the cumulative effects of the 
factors and replaces a standalone cumulative effects analysis.

Species Viability

    For relict darter populations to be sufficiently resilient, the 
needs of individuals (slow-flowing riffles and pools, appropriate 
substrate, food availability, water quality, and aquatic vegetation or 
large woody debris for cover) must be met at a larger scale. Stream 
reaches with suitable habitat must be large enough to support an 
appropriate number of individuals to avoid issues associated with small 
population size, such as inbreeding depression and the Allee effect 
(low population density reducing the probability of encountering mates 
for spawning). Connectivity of stream reaches allows for immigration 
and emigration between populations and increases the likelihood of 
recolonization should a population be lost. At the species level, the 
relict darter needs well-distributed healthy populations to withstand 
environmental stochasticity (resiliency) and catastrophes (redundancy) 
and to adapt to biological and physical changes in its environment 
(representation). To evaluate the current and future viability of the 
relict darter, we assessed a range of conditions to allow us to 
estimate the species' resiliency, representation, and redundancy.
    We delineated analytical units (populations) by dividing the relict 
darter's range into two units (Bayou de Chien/Jackson Creek and Little 
Bayou de Chien) based on known occurrence records, the substantial 
distance (18.3 kilometers (km) (11.4 miles (mi)) separating known 
occurrence records in both watersheds, and unsuitable habitat

[[Page 66288]]

conditions in downstream reaches of both watersheds.
    To assess resiliency, we evaluated four components that relate to 
the species' habitat or its population demography: physical habitat, 
water quality, mean density, and occurrence complexity. We assessed 
habitat using two components describing physical habitat quality and 
water quality. The demographic condition was assessed using mean 
density and occurrence complexity. We established parameters for each 
condition category by evaluating the range of existing data and 
separating those data into categories based on our understanding of the 
species' demographics and habitat (see table 1, below). Individual 
component scores were combined and averaged to produce an overall 
condition score for each population.

              Table 1--Component Conditions Used To Assess Resiliency for Relict Darter Populations
----------------------------------------------------------------------------------------------------------------
                                                                   Condition
          Component           ----------------------------------------------------------------------------------
                                       High                Moderate                 Low                 0
----------------------------------------------------------------------------------------------------------------
Physical Habitat.............  Silt deposition low;  Silt deposition       Silt deposition       Habitat
                                no extensive or       moderate; habitat     extensive; habitats   unsuitable
                                significant habitat   alterations at        severely altered      (species
                                alterations (e.g.,    moderate levels--     and recognized as     absent).
                                recent                channelization or     impacting the
                                channelization,       other habitat         species; <25% of
                                riparian clearing);   disturbance more      habitats suitable
                                >75% of available     widespread; 25-75%    for the species.
                                habitat suitable      of available
                                for the species.      habitat suitable
                                                      for the species.
Water Quality................  Minimal or no known   WQ issues recognized  WQ issues prevalent   Habitat
                                water quality (WQ)    and may impact        within system,        unsuitable
                                issues (i.e., no      species (i.e., 1 or   likely impacting      (species
                                303(d) streams        2 303(d) streams).    populations (i.e.,    absent).
                                impacting the                               numerous 303(d)
                                species *).                                 streams).
Mean Density (# darters/m\2\)  >0.15...............  0.05-0.15...........  <0.05...............  Species absent.
Occurrence Complexity........  Occupies main         Occupies main         Occupies main         Species absent.
                                channel and >=3       channel and maximum   channel and maximum
                                tributaries.          of 2 tributaries.     of <=1 tributary.
----------------------------------------------------------------------------------------------------------------
* Signifies streams identified by the State of Kentucky on the list of impaired streams required by section
  303(d) of the Clean Water Act (33 U.S.C. 1313(d)).

    Our evaluation of representation for the relict darter was based on 
the species' genetic diversity and the extent and variability of 
environmental diversity (habitat diversity) across the species' 
geographical range. Additionally, we assessed relict darter redundancy 
(ability of the species to withstand catastrophic events) by evaluating 
the number and distribution of populations with high resilience 
throughout the species' range. Highly resilient populations, coupled 
with a broad distribution throughout the historical range, have a 
positive relationship to species-level redundancy.

Current Condition of the Relict Darter

    The relict darter's historical range included the Bayou de Chien 
stream system, a 554-km\2\ (214-mi\2\) watershed located within the 
Mississippi Valley Loess Plains ecoregion (Woods et al. 2002, entire) 
in Fulton, Graves, and Hickman Counties, Kentucky (Webb and Sisk 1975, 
entire; Warren et al. 1994, entire; Piller and Burr 1998, entire). 
Bayou de Chien is a low-gradient stream with a sand, gravel, and silt 
bottom that begins in southwestern Graves County and flows westward 
approximately 47 km (29.2 mi) through Hickman and Fulton Counties, 
before ultimately emptying into Obion Creek near Hickman, Kentucky. 
Historically, Bayou de Chien was presumably an undisturbed, free-
flowing stream with alternating areas of riffles, runs, and pools; 
however, only a few of these reaches remain because much of the stream 
has been channelized and converted to a deep ditch with uniform depth, 
velocity, and substrate (Piller and Burr 1998, pp. 64-65).
    The relict darter's current range is also limited to the Bayou de 
Chien system in Fulton, Graves, and Hickman Counties, Kentucky. Recent 
surveys (2010-2019) indicate that the species is now known by two 
geographically separated populations: Bayou de Chien/Jackson Creek and 
Little Bayou de Chien. Within the Bayou de Chien/Jackson Creek 
population, the species occupies patches of suitable habitat within a 
30.4-km (18.9-mi) reach of Bayou de Chien, a 3.6-km (2.3-mi) reach of 
Jackson Creek, a 3.2-km (2.0-mi) reach of South Fork Bayou de Chien, a 
10.4-km (6.5-mi) reach of Cane Creek, and a 2.3-km (1.4-mi) reach of 
Sand Creek. Within the Little Bayou de Chien population, the species 
occupies patches of suitable habitat within a 2.6-km (1.6-mi) reach. In 
total, the species currently occupies 52.5 stream km (32.7 stream mi).
    The Bayou de Chien/Jackson Creek population exhibits moderate 
resiliency, as evidenced by recent estimates of mean density and mean 
population size, recent monitoring data showing evidence of 
reproduction and recruitment, and our observations of moderate to high 
physical habitat and water quality conditions within the watershed (see 
table 2, below; Service 2020, p. 35). Based on recent surveys, Jackson 
Creek and Bayou de Chien have moderate to high relict darter densities, 
with population estimates of 1,888 and 22,798 fish, respectively, 
indicating that the population size has more than doubled since a 
decade ago (Service 2019, p. 7; Service 2020, p. 36). Resiliency of the 
Little Bayou de Chien population is lower due to its lower mean density 
and less optimal habitat conditions (see table 2, below). The species 
was only recently discovered in the Little Bayou de Chien in July 2017. 
Recent survey efforts have been limited to two 100-m reaches and 
several qualitative searches. Population size has not been estimated in 
these reaches because of the limited quantitative effort; however, 23 
relict darters were observed. Low levels of reproduction and 
recruitment are assumed for the Little Bayou de Chien. Overall, the 
rangewide mean population estimate is 24,686 relict darters (Service 
2019, p. 7).
    We consider redundancy and representation of the relict darter to 
be low due to the species' small number of populations, its low 
effective population size (mean of 221.5, with a 95 percent confidence 
interval of 143.3-448.3), and its reduced genetic diversity (see table 
2, below; Kattawar and Piller 2020, pp. 27-28). We recognize that 
redundancy and representation may be inherently low for a narrow 
endemic like the relict darter. The fact that the species exhibits 
little genetic variation across its range and has a very low effective 
population size suggests a past population bottleneck (e.g., rangewide 
habitat disturbance) and subsequent genetic drift (loss of rare alleles 
in a small population) (Kattawar and Piller 2020, entire).

[[Page 66289]]



                    Table 2--Resiliency, Redundancy, Representation Summary for Relict Darter
----------------------------------------------------------------------------------------------------------------
             Population                       Resiliency                Redundancy            Representation
----------------------------------------------------------------------------------------------------------------
Bayou de Chien/Jackson Creek........  Moderate..................  Naturally Low--the      Low--low genetic
Little Bayou de Chien...............  Low.......................   species is a narrowly   diversity and low
                                                                   distributed endemic;    effective population
                                                                   populations appear to   size.
                                                                   be separated, but
                                                                   connectivity exists
                                                                   within Bayou de
                                                                   Chien, Jackson Creek,
                                                                   and other large
                                                                   tributaries.
----------------------------------------------------------------------------------------------------------------

    As a narrow endemic species located in one watershed in 
southwestern Kentucky, the relict darter has inherently low redundancy, 
with only one known population at the time of listing and currently two 
known populations. Representation is also limited based on its 
restricted range, yet the species has survived a likely population 
bottleneck. Despite low genetic diversity, genetic analyses indicate a 
single panmictic population, indicating some recent genetic exchange 
between populations. Low species redundancy and representation are 
tempered by the moderate resiliency of the Bayou de Chien/Jackson Creek 
population. This historical population continues to exhibit resiliency 
today, with high relict darter abundance and evidence of continued 
reproduction. This moderately resilient population has survived 
threats, primarily because conservation efforts over the past three 
decades have improved habitat within the system, thus enabling the 
breeding, feeding, and sheltering needs of the relict darter to be met 
and thus sustaining the population over time.

Future Conditions

    In our SSA (Service 2020, entire), we defined viability as the 
ability of the species to sustain populations in the wild over time. To 
help address uncertainty associated with the degree and extent of 
potential future stressors and their impacts on the species' needs, the 
concepts of resiliency, redundancy, and representation were assessed 
using three plausible future scenarios (continuation of current trend, 
improving trend, and worsening trend), using the same analytical units 
and components described above, in Summary of Biological Status and 
Threats. We devised these scenarios by identifying data sources related 
to the primary threats anticipated to affect the relict darter in the 
future. For the habitat loss and degradation threat, we looked at land 
cover change and urbanization, as well as conservation activity, and we 
also included predicted impacts of future climate change. The three 
scenarios capture the range of uncertainty in the changing landscape 
and how relict darter will respond to the changing conditions (see 
table 3, below). We used the best available data and models to project 
out 50 years into the future (i.e., 2070), a timeframe where we were 
reasonably certain the land use change, urbanization, and climate 
models used could project patterns in the species' range relevant to 
the relict darter and its habitat given the species' lifespan, as well 
as the amount of time for the species to respond to the threats. For 
each scenario, we provided a summary of resiliency for each population 
at 10, 30, and 50 years in the future. For more information on the 
models and their projections, please see the SSA report (Service 2020, 
entire).

                      Table 3--Future Condition of the Relict Darter by the Years 2030, 2050, and 2070 Under Three Future Scenarios
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Predicted future condition
         Scenario                Population       ------------------------------------------------------------------------------------------------------
                                                                10 Years                          30 Years                          50 Years
--------------------------------------------------------------------------------------------------------------------------------------------------------
1........................  Bayou de Chien/Jackson  Moderate.........................  Moderate........................  Moderate.
                           Little Bayou de Chien.  Low..............................  Low.............................  Low.
2........................  Bayou de Chien/Jackson  Moderate.........................  Moderate-High...................  Moderate-High.
                           Little Bayou de Chien.  Low..............................  Low-Moderate....................  Moderate.
3........................  Bayou de Chien/Jackson  Moderate.........................  Low-Moderate....................  Low.
                           Little Bayou de Chien.  Low..............................  Potential Extirpation...........  Potential Extirpation.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Under Scenario 1 (continuation of current trend), small increases 
in urbanization were predicted by 2050 and 2070 within the watersheds 
of both extant populations (Service 2020, pp. 41-43), but associated 
negative effects on habitat and population elements were expected to be 
minimal. We also predicted continued implementation of conservation 
actions under KDFWR's conservation strategy and through the Service's 
PFW program. Using a moderate level of climate change (RCP 4.5), within 
the next 10 years, portions of the Bayou de Chien system were impacted 
by either drought or floods, with slightly warmer temperatures. Over 
the long term (30-50 years), drought affected all populations but at 
intervals and severity levels similar to what has occurred over the 
last 10 years.
    Considering all of these factors, we expect no change in resiliency 
for the two known populations; however, the low resiliency of the 
Little Bayou de Chien population makes it much more vulnerable to 
extirpation from the effects of stochastic disturbance. Under Scenario 
1, both representation and redundancy of the relict darter are expected 
to remain at low levels. The species is limited to one low resiliency 
population and one moderate resiliency population, both of which occupy 
streams within a single ecoregion, Mississippi Valley Loess Plains. 
Within this ecoregion, relict darters occupy second- to fourth-order 
reaches, but habitat diversity within these reaches tends to be low. 
The species also has low genetic diversity, which cannot be increased 
through augmentations, reintroductions, or other genetics-based 
conservation actions because genetic diversity cannot be created for a 
species that has a limited gene pool. The species' low genetic 
diversity could potentially limit its ability to adapt to changing 
environmental conditions over time. Furthermore, both populations will 
remain vulnerable to catastrophic events, such as an extreme drought or 
chemical spill, because the species' distribution is generally limited 
to a

[[Page 66290]]

single, continuous stream reach within each population.
    Under Scenario 2 (improving trend), we projected a number of 
improved conditions and positive outcomes that led to overall improved 
resiliency and redundancy for the relict darter. We projected both land 
use change and urbanization to be lower than current rates. The current 
trend in climate improved, with lower annual increases in temperature 
and less severe droughts or floods in the short term (RCP 4.5). Over 
the long term (30-50 years), drought affected both populations but at 
intervals and severity levels lower than what occurred over the last 10 
years. Conservation efforts, including new efforts along occupied 
reaches of Little Bayou de Chien, increased through State wildlife 
action plans, and other Service partnerships with Federal, State, and 
nongovernmental partners. These actions contributed to improved water 
quality conditions, increases in forest and riparian cover, and 
reductions in point source and nonpoint-source pollutants in all 
historical tributary systems.
    Based on these habitat and water quality improvements, we expect 
both extant populations to increase in size, with continued 
reproduction and recruitment. We also expect these populations to 
expand into unoccupied historical tributaries, eventually resulting in 
improved occurrence complexity in both watersheds. All of these actions 
and conditions will result in increased resiliency for the Bayou de 
Chien/Jackson and Little Bayou de Chien populations over the next 30-50 
years. Under Scenario 2, representation of the relict darter is 
expected to remain at a low level. The species' expansion within the 
Bayou de Chien and Little Bayou de Chien watersheds will bolster the 
species' resiliency and redundancy, but the species' low genetic 
diversity cannot be increased. Under Scenario 2, redundancy of the 
relict darter will increase due to the species' expansion and improved 
resiliency within the Bayou de Chien and Little Bayou de Chien 
watersheds and due to the species' recolonization of historical 
tributaries such as South Fork Bayou de Chien. This increased 
redundancy will decrease the likelihood that a catastrophic event, such 
as an extreme drought or pollution event, would lead to the species' 
extinction. Under Scenario 2, we expect the relict darter to exhibit 
low-moderate redundancy.
    Under Scenario 3 (worsening trend), we projected rates of land use 
change and urbanization to be higher than current rates. Under this 
scenario, the current trend in climate worsened (high RCP of 8.5), and 
within the next 10 years, populations were impacted by either drought 
or floods, with warmer stream temperatures and lower rainfall. Over the 
long term (30-50 years), drought affected both populations at intervals 
and severity levels higher than what has occurred over the last 10 
years. Some conservation actions continued in the Bayou de Chien 
system, but there was a net decrease in these activities due to reduced 
agency funding. All of these actions and conditions resulted in 
declining habitat and water quality conditions that will negatively 
affect resiliency estimates for both extant populations.
    For this scenario, we project low resiliency for the Bayou de 
Chien/Jackson population and potential extirpation of the Little Bayou 
de Chien population by 2070. Under Scenario 3, representation of the 
relict darter is expected to remain at a low level. Reduced resiliency 
of the Bayou de Chien/Jackson Creek population and extirpation of the 
Little Bayou de Chien population will increase the species' 
vulnerability to stochastic disturbance and will likely reduce the 
species' ability to adapt to changing environmental conditions. Under 
Scenario 3, redundancy of the relict darter is expected to remain at a 
low level; however, extirpation of the Little Bayou de Chien population 
reduces the species' range, leaving it with a single population (Bayou 
de Chien/Jackson Creek) that is more vulnerable to a catastrophic event 
such as an extreme drought or chemical spill. The species' redundancy 
is also weakened by lower resiliency of the Bayou de Chien/Jackson 
Creek population, which will be faced with declining physical habitat 
and water quality conditions.

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

Status Throughout All of Its Range

    After evaluating threats to the species and assessing the 
cumulative effect of the threats under the Act's section 4(a)(1) 
factors, we conclude that the risk factors acting on the relict darter 
and its habitat, either singly or in combination, are not of sufficient 
imminence, intensity, or magnitude to indicate that the species is in 
danger of extinction (an endangered species) throughout all of its 
range. As described above in Current Condition of the Relict Darter, 
the relict darter is naturally a narrow endemic species. Its low 
species redundancy and representation are tempered by the moderate 
resiliency of the Bayou de Chien/Jackson Creek population, which has 
high relict darter abundance and evidence of continued reproduction. 
Population size has increased and recruitment trends have improved 
based on surveys completed during the past decade. Further, this 
moderate resiliency population has survived threats, primarily because 
conservation efforts over the past three decades have improved and 
protected habitat within the system, enabling the breeding, feeding, 
and sheltering needs of the relict darter to be met and thus sustaining 
the population over time. The Service continues to work with partners 
on these projects. Additionally, a second population in the Little 
Bayou de Chien was discovered in 2017. While this newly discovered 
population has low resiliency, the addition of a second population adds 
to the species' redundancy.
    Our analysis of the relict darter's current condition shows that 
while the species has maintained resiliency since it was listed (see 58 
FR 68480; December 27, 1993), it is now represented by only two 
populations in one watershed, and thus redundancy is still inherently 
low. The species also has low representation based on its reduced 
genetic diversity and low effective population size (Factor E), likely 
a result of a population bottleneck caused by extensive channelization 
and habitat disturbance throughout the Bayou de Chien system in the 
early 20th century. Habitat loss and degradation through stream channel 
disturbance, removal of riparian vegetation, and pollution continue to 
affect the species (Factor A), even though conservation actions over 
the past three decades have led to improved habitat conditions in

[[Page 66291]]

portions of the Bayou de Chien mainstem and Jackson Creek, contributing 
to moderate resiliency for the larger population. The current 
resiliency of the Jackson Creek/Bayou de Chien population, with a 
population size that has doubled in the past decade to nearly 25,000 
relict darters showing evidence of reproduction and successful 
recruitment, along with the added redundancy of the newly discovered 
Little Bayou de Chien population and the reduced habitat threats, 
indicate that the species is not currently in danger of extinction. 
Therefore, after assessing the best available information, we conclude 
that the relict darter no longer meets the Act's definition of an 
endangered species.
    The relict darter has benefited from protection as an endangered 
species under the Act, and from improvements in water quality and 
habitat conditions stemming from both national and Kentucky statutes 
and regulations; however, these regulations have not prevented the 
degradation of some habitats used by the species (Factor D). The 
primary threats that are currently acting on the species are expected 
to continue into the future, climate change (Factor E) is expected to 
exacerbate existing threats, and the species' low redundancy and low 
representation put the species at risk of extinction within the 
foreseeable future throughout all of its range. Fifty years was 
considered ``foreseeable'' in this case because we can reasonably 
determine within this 50-year timeframe that both the threats as 
presented in the models of predicted urbanization, land use, and 
climate change and the species' responses to those threats are likely.
    The range of plausible future scenarios of relict darter habitat 
conditions and water quality factors suggest slightly variable 
resilience into the future. Under the continuation of current trend 
scenario (Scenario 1), resiliency remains low or moderate in the two 
populations, with redundancy and representation remaining low. Under 
the improving trend scenario (Scenario 2), resiliency improves for both 
populations, with habitat conditions predicted to improve because of an 
increased percentage of forested land with reduced percentages of both 
agricultural land and urbanization, along with reduced climate change 
rates. Representation remains low under this scenario, but redundancy 
improves because of reintroduction of the species into historical 
habitats or natural expansion within the system. There is greater 
uncertainty regarding the species' future status, primarily due to 
conservation action implementation with this scenario than in the other 
two future scenarios. Under the worsening trend scenario (Scenario 3), 
resiliency is low in the one remaining population, and one population 
is likely extirpated resulting in reduced redundancy and low 
representation. This expected reduction in both the number and 
distribution of resilient populations is likely to increase the 
species' vulnerability to both stochastic and catastrophic 
disturbances. Compared to the other two scenarios, the conditions from 
Scenario 3 were considered more likely to contribute to the future 
condition of the species, primarily because of expected continued 
sedimentation and water quality degradation combined with the expected 
synergistic effects of climate change in the future.
    In summary, while the relict darter's viability has improved over 
time (see Conservation Efforts, above), three major factors that are 
influencing the viability of the species are expected to affect it into 
the future: habitat loss and degradation, restricted range/isolation, 
and climate change. Habitat loss and degradation resulting from 
siltation, channelization/riparian vegetation removal, drainage of 
riparian wetlands, and water quality degradation (pollution) pose the 
largest risk to the current and future viability of the relict darter. 
With the plausibility of future land use changes that could impact 
instream habitat and water quality, the projected worsening climate 
conditions, and given the inherently low redundancy that increases 
vulnerability to catastrophic events, the relict darter is at risk of 
extinction within the next 50 years. Thus, after assessing the best 
available information, we conclude that the relict darter is not 
currently in danger of extinction, but it is likely to become in danger 
of extinction within the foreseeable future throughout all of its 
range.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. The court in Center for Biological Diversity v. Everson, 
2020 WL 437289 (D.D.C. Jan. 28, 2020) (Center for Biological 
Diversity), vacated the aspect of the Final Policy on Interpretation of 
the Phrase ``Significant Portion of Its Range'' in the Endangered 
Species Act's Definitions of ``Endangered Species'' and ``Threatened 
Species'' (79 FR 37578; July 1, 2014) that provided that the Service 
does not undertake an analysis of significant portions of a species' 
range if the species warrants listing as threatened throughout all of 
its range. Therefore, we proceed to evaluating whether the species is 
endangered in a significant portion of its range--that is, whether 
there is any portion of the species' range for which both (1) the 
portion is significant; and (2) the species is in danger of extinction 
in that portion. Depending on the case, it might be more efficient for 
us to address the ``significance'' question or the ``status'' question 
first. We can choose to address either question first. Regardless of 
which question we address first, if we reach a negative answer with 
respect to the first question that we address, we do not need to 
evaluate the other question for that portion of the species' range.
    Following the court's holding in Center for Biological Diversity, 
we now consider whether there are any significant portions of the 
species' range where the species is in danger of extinction now (i.e., 
endangered). In undertaking this analysis for relict darter, we choose 
to address the significance question first. First, we assessed the two 
portions of the range (Bayou de Chien/Jackson Creek and Little Bayou de 
Chien). In the absence of a legal definition of significance in the 
Act, we determined significance on a case-by-case basis for the relict 
darter using a reasonable interpretation of significance and providing 
a rational basis for our determination. In doing so, we considered what 
is currently observed about the contributions made by each geographic 
portion in terms of biological factors, focusing on the importance of 
each in supporting the continued viability of the species. We evaluated 
whether these areas occupy relatively large or particularly high-
quality or unique habitat. As a narrow ranging endemic, both relict 
darter populations occur within one 554-km\2\ (214-mi\2\) watershed in 
three counties in southwestern Kentucky (Service 2020, p. 17), and 
Little Bayou de Chien is a tributary to Bayou de Chien. We determined 
that the Bayou de Chien/Jackson Creek portion is significant, as it is 
large geographically relative to the entire range of the species, it 
contains high-quality/high-value habitat for the species, and it 
contains habitat essential to the relict darter's life history; 
therefore, it is important for the overall conservation of the species. 
We determined that the Little Bayou de Chien portion is not 
significant, as it constitutes a very small portion (i.e., less than 5 
percent) of the range and

[[Page 66292]]

does not represent unique or high-quality habitat for the relict 
darter.
    Since we determined that Bayou de Chien/Jackson Creek is a 
significant portion, we next evaluate whether the relict darter is in 
danger of extinction (i.e., endangered) in that portion. The Bayou de 
Chien/Jackson Creek population has high relict darter abundance and 
evidence of continued reproduction. Population size has increased and 
recruitment trends have improved based on surveys completed during the 
past decade. Further, this moderate resiliency population has survived 
threats, primarily because conservation efforts over the past three 
decades have improved and protected habitat within the system, enabling 
the breeding, feeding, and sheltering needs of the relict darter to be 
met and thus sustaining the population over time. Thus, the Bayou de 
Chien/Jackson Creek portion is not in danger of extinction and does not 
have a different status than the entire range. Based on this, there are 
no portions of the species' range that provide a basis for determining 
that the species is in danger of extinction in a significant portion of 
its range, and we determine that the species is likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range. This is consistent with the courts' holdings in Desert 
Survivors v. Department of the Interior, No. 16-cv-01165-JCS, 2018 WL 
4053447 (N.D. Cal. Aug. 24, 2018), and Center for Biological Diversity 
v. Jewell, 248 F. Supp. 3d, 946, 959 (D. Ariz. 2017).

Determination of Status

    Our review of the best scientific and commercial data available 
indicates that the relict darter meets the Act's definition of a 
threatened species. Therefore, we reclassify the relict darter as a 
threatened species in accordance with sections 3(20) and 4(a)(1) of the 
Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. The Act encourages cooperation with the States and requires 
that recovery actions be implemented for all listed species. The 
protections required by Federal agencies and the prohibitions against 
certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Section 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystem.
    Revisions of the plan may be done to address continuing or new 
threats to the species, as new substantive information becomes 
available. The recovery plan identifies site-specific management 
actions that set a trigger for review of the five factors that control 
whether a species may be downlisted or delisted, and methods for 
monitoring recovery progress. Recovery plans also establish a framework 
for agencies to coordinate their recovery efforts and provide estimates 
of the cost of implementing recovery tasks. All planning documents can 
be found on our website (https://www.fws.gov/program/endangered-species), or from our Kentucky Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands (such as TNC preserves and county-owned nature 
preserves). To achieve recovery of these species requires cooperative 
conservation efforts on private, State, and Tribal lands where 
appropriate. Funding for recovery actions could become available from a 
variety of sources, including Federal budgets, State programs, and cost 
share grants from non-Federal landowners, the academic community, and 
nongovernmental organizations. We invite you to submit any new 
information on this species whenever it becomes available (see FOR 
FURTHER INFORMATION CONTACT).
    Section 7(a) requires Federal agencies to evaluate their actions 
with respect to any species that is listed as an endangered or 
threatened species. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR part 402. 
Section 7(a)(2) of the Act requires Federal agencies to ensure that 
activities they authorize, fund, or carry out are not likely to 
jeopardize the continued existence of the species. If a Federal action 
may affect a listed species, the responsible Federal agency must enter 
into consultation with the Service.
    Federal agency actions within the species' habitat that may require 
consultation as described in the preceding paragraph include management 
and any other landscape-altering activities on Federal lands 
administered by the U.S. Forest Service; issuance of section 404 Clean 
Water Act (33 U.S.C. 1251 et seq.) permits by the U.S. Army Corps of 
Engineers; and construction and maintenance of roads or highways by the 
Federal Highway Administration.

II. Final Rule Issued Under Section 4(d) of the Act

    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a listing on 
proposed and ongoing activities within the range of the listed species. 
The Act allows the Secretary to promulgate protective regulations for 
threatened species pursuant to section 4(d) of the Act. Because we are 
reclassifying this species as a threatened species, the prohibitions in 
section 9 do not apply directly. We are, therefore, adopting a set of 
regulations to provide for the conservation of the species in 
accordance with section 4(d), which also authorizes us to apply any of 
the prohibitions in section 9 to a threatened species. The discussion 
below regarding protective regulations under section 4(d) of the Act 
complies with our policy.

Background

    Section 4(d) of the Act contains two sentences. The first sentence 
states that the Secretary shall issue such regulations as she deems 
necessary and advisable to provide for the conservation of species 
listed as threatened species. The U.S. Supreme Court has noted that 
statutory language similar to the language in section 4(d) of the Act 
authorizing the Secretary to take action that she ``deems necessary and 
advisable'' affords a large degree of deference to the agency (see 
Webster v.

[[Page 66293]]

Doe, 486 U.S. 592, 600 (1988)). Conservation is defined in the Act to 
mean the use of all methods and procedures which are necessary to bring 
any endangered species or threatened species to the point at which the 
measures provided pursuant to the Act are no longer necessary. 
Additionally, the second sentence of section 4(d) of the Act states 
that the Secretary may by regulation prohibit with respect to any 
threatened species any act prohibited under section 9(a)(1), in the 
case of fish or wildlife, or section 9(a)(2), in the case of plants. 
Thus, the combination of the two sentences of section 4(d) provides the 
Secretary with wide latitude of discretion to select and promulgate 
appropriate regulations tailored to the specific conservation needs of 
the threatened species. The second sentence grants particularly broad 
discretion to the Service when adopting one or more of the prohibitions 
under section 9.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld, as a valid 
exercise of agency authority, rules developed under section 4(d) that 
included limited prohibitions against takings (see Alsea Valley 
Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington 
Environmental Council v. National Marine Fisheries Service, 2002 WL 
511479 (W.D. Wash. 2002)). Courts have also upheld 4(d) rules that do 
not address all of the threats a species faces (see State of Louisiana 
v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted in the legislative 
history when the Act was initially enacted, ``once an animal is on the 
threatened list, the Secretary has an almost infinite number of options 
available to [her] with regard to the permitted activities for those 
species. [She] may, for example, permit taking, but not importation of 
such species, or [she] may choose to forbid both taking and importation 
but allow the transportation of such species'' (H.R. Rep. No. 412, 93rd 
Cong., 1st Sess. 1973).
    Exercising its authority under section 4(d), the Service has 
developed a rule that is designed to address the relict darter's 
specific threats and conservation needs. Although the statute does not 
require us to make a ``necessary and advisable'' finding with respect 
to the adoption of specific prohibitions under section 9, we find that 
this rule as a whole satisfies the requirement in section 4(d) of the 
Act to issue regulations deemed necessary and advisable to provide for 
the conservation of the relict darter. As discussed above under Summary 
of Biological Status and Threats, we have concluded that the relict 
darter is likely to become in danger of extinction within the 
foreseeable future primarily due to habitat degradation and loss 
stemming from siltation, channelization and riparian vegetation 
removal, riparian wetland drainage, and water quality degradation. 
These threats contribute to the negative effects associated with the 
species' restricted range and effects of climate change. The provisions 
of this 4(d) rule will promote conservation of the relict darter by 
providing continued protection from take and encouraging management of 
the landscape in ways that meet both watershed and riparian management 
considerations and the conservation needs of the relict darter. The 
provisions of this rule are one of many tools that we will use to 
promote the conservation of the relict darter.
    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they fund, authorize, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species.
    If a Federal action may affect a listed species or its critical 
habitat, the responsible Federal agency (action agency) must enter into 
consultation with us. Examples of actions that are subject to the 
section 7 consultation process are actions on State, Tribal, local, or 
private lands that require a Federal permit (such as a permit from the 
U.S. Army Corps of Engineers under section 404 of the Clean Water Act 
(33 U.S.C. 1251 et seq.) or a permit from the Service under section 10 
of the Act) or that involve some other Federal action (such as funding 
from the Federal Highway Administration, Federal Aviation 
Administration, or the Federal Emergency Management Agency). Federal 
actions not affecting listed species or critical habitat--and actions 
on State, Tribal, local, or private lands that are not federally 
funded, authorized, or carried out by a Federal agency--do not require 
section 7 consultation.
    This obligation does not change in any way for a threatened species 
with a species-specific 4(d) rule. Actions that result in a 
determination by a Federal agency of ``not likely to adversely affect'' 
continue to require the Service's written concurrence and actions that 
are ``likely to adversely affect'' a species require formal 
consultation and the formulation of a biological opinion.

Provisions of the 4(d) Rule

    The provisions of this 4(d) rule will promote conservation of the 
relict darter by adopting the same prohibitions that apply to an 
endangered species under section 9 of the Act and 50 CFR 17.21. Except 
as otherwise authorized or permitted, this 4(d) rule continues to 
prohibit importing or exporting; take; possession and other acts with 
unlawfully taken specimens; delivering, receiving, carrying, 
transporting, or shipping in interstate or foreign commerce in the 
course of commercial activity; and selling or offering for sale in 
interstate or foreign commerce. The prohibitions apply throughout the 
species' range.
    Identical to the regulations that apply under endangered status, 
the prohibitions in this 4(d) rule prohibit all forms of take within 
the United States. Under the Act, ``take'' means to harass, harm, 
pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to 
attempt to engage in any such conduct. Some of these provisions have 
been further defined in regulations at 50 CFR 17.3. Take can result 
knowingly or otherwise, by direct and indirect impacts, intentionally 
or incidentally. Regulating intentional and incidental take will help 
preserve the species' remaining populations, enable beneficial 
management actions to occur, and decrease synergistic, negative effects 
from other stressors.
    This 4(d) rule prohibits intentional take, including capturing and 
handling, because these activities require training and experience. 
Such activities include, but are not limited to, monitoring and 
research involving capturing and handling relict darters. While these 
activities are important to relict darter recovery, there are proper 
techniques for capturing and handling fish that require training and 
experience. Improper capture or handling can cause injury or even 
result in death of relict darters. Therefore, to ensure that these 
activities continue to be conducted correctly by properly trained 
personnel, the 4(d) rule prohibits intentional take; however, these 
activities could be covered under a permit issued under section 
10(a)(1)(A) of the Act.
    Threats to the species are noted above and described in detail 
under Summary of Biological Status and Threats. The most significant 
threat expected to affect the species in the foreseeable future is 
habitat loss and degradation from siltation, channelization and 
riparian vegetation removal, drainage of riparian wetlands, and water 
quality degradation. Some activities have the potential to affect the 
relict darter,

[[Page 66294]]

including agriculture and land development. These activities may result 
in incidental take through increases in siltation, diminishing water 
quality, altering stream flow, and reducing fish passage. Therefore, 
this 4(d) rule prohibits take to help preserve the relict darter's 
remaining populations, slow the rate of population decline, preserve 
and potentially provide for expansion of the population, and decrease 
synergistic, negative effects from other stressors.
    We may issue permits to carry out otherwise prohibited activities, 
including those described above, involving threatened wildlife under 
certain circumstances. Regulations governing permits are codified at 50 
CFR 17.32. With regard to threatened wildlife, a permit may be issued 
for the following purposes: for scientific purposes, to enhance 
propagation or survival, for economic hardship, for zoological 
exhibition, for educational purposes, for incidental taking, or for 
special purposes consistent with the purposes of the Act. The statute 
also contains certain exemptions from the prohibitions, which are found 
in sections 9 and 10 of the Act.

Exceptions

    The 4(d) rule also provides for the conservation of the species by 
incorporating several exceptions to allow for routine enforcement 
activities, allow for assisting sick or injured fish, and encourage the 
active habitat management this species uniquely requires. The statute 
also contains certain statutory exceptions from the prohibitions, which 
are found in sections 9 and 10 of the Act, and other regulatory 
exceptions from the prohibitions, which are found in our regulations at 
50 CFR part 17, subparts C and D. Below, we describe these exceptions 
to the prohibitions for the relict darter.
    To start, this rule outlines several regulatory exceptions to the 
prohibitions for the relict darter. First, the rule excepts take 
associated with activities that are authorized by permits under Sec.  
17.32. This means that if a manager has received or receives a permit 
for a particular activity (e.g., a section 10(a)(1)(A) permit for 
monitoring relict darters), any take that occurs as a result of 
activities covered by this permit remains excepted from the 
prohibitions on take under the issued permit; in other words, the 
manager would not be liable for any take for which the manager already 
has a permit.
    Second, the final rule incorporates certain regulatory exceptions 
that allow take by any person in defense of his own life or the lives 
of others; take by representatives of the Service or of a State 
conservation agency to aid a sick specimen or to dispose of, salvage, 
or remove a dead specimen that is reported to the Office of Law 
Enforcement; and take by Federal and State law enforcement officers 
performing their official duties to possess, deliver, carry, transport, 
or ship any relict darters taken in violation of the Act, as necessary.
    Next, the final 4(d) rule allows employees of State conservation 
agencies operating under a cooperative agreement with the Service in 
accordance with section 6(c) of the Act to take relict darters in order 
to carry out conservation programs for the species. We recognize the 
special and unique relationship with our State natural resource agency 
partners in contributing to conservation of listed species. State 
agencies often possess scientific data and valuable expertise on the 
status and distribution of endangered, threatened, and candidate 
species of wildlife and plants. State agencies, because of their 
authorities and their close working relationships with local 
governments and landowners, are in a unique position to assist us in 
implementing all aspects of the Act. In this regard, section 6 of the 
Act provides that we shall cooperate to the maximum extent practicable 
with the States in carrying out programs authorized by the Act. 
Therefore, any qualified employee or agent of a State conservation 
agency that is a party to a cooperative agreement with us in accordance 
with section 6(c) of the Act, who is designated by his or her agency 
for such purposes, will be able to conduct activities designed to 
conserve the relict darter that may result in otherwise prohibited take 
without additional authorization.
    Finally, the 4(d) rule provides species-specific exceptions to the 
standard take prohibitions; these species-specific exceptions 
facilitate continued and increased implementation of beneficial 
management practices that provide for conservation of the species. 
Within each occupied stream, restoration actions will promote expansion 
of the relict darter's range and reduce the fragmentation and isolation 
of populations. These actions can reduce stressors that impact the 
relict darter, including runoff of siltation and pollution, and may 
(through riparian reforestation) mediate local water temperatures 
expected to increase with climate change. Incidental take associated 
with habitat restoration actions excepted by the 4(d) rule may result 
in some minimal level of harm or temporary disturbance to the relict 
darter. For example, a culvert replacement project would likely elevate 
suspended sediments for several hours, and the darters would need to 
move out of the sediment plume to resume normal feeding behavior. 
Because 4(d) rule exceptions do not apply during the relict darter's 4-
month spawning period, a critical phase of the species' life history, 
the potential for incidental take is further minimized.
    Overall, these activities benefit the species by expanding suitable 
habitat and reducing within-population fragmentation, contributing to 
conservation and recovery. Consistent with all of the exceptions and 
based on the best available information, our 4(d) rule excepts 
incidental take associated with the following activities, if carried 
out in accordance with existing regulations and permit requirements, 
and conducted outside the March through June spawning season:
     Channel restoration or improvement projects that create 
natural, physically stable, ecologically functioning streams (or stream 
and wetland systems) that are reconnected with their groundwater 
aquifers and, if the projects involve known relict darter spawning 
habitat, take place between June 30 and March 1. These projects can be 
accomplished using a variety of methods, but the desired outcome is a 
natural channel with low shear stress (force of water moving against 
the channel); bank heights that enable reconnection to the floodplain; 
a reconnection of surface and groundwater systems, resulting in 
perennial flows in the channel; riffles and pools composed of existing 
soil, rock, and wood instead of large imported materials; low 
compaction of soils within adjacent riparian areas; and inclusion of 
riparian wetlands.
     Streambank stabilization projects that use bioengineering 
methods to replace preexisting, bare, eroding stream banks with 
vegetated, stable stream banks, thereby reducing bank erosion and 
instream sedimentation and improving habitat conditions for the species 
and, if the projects involve known relict darter spawning habitat, that 
take place between June 30 and March 1. Stream banks may be stabilized 
using native live stakes (live, vegetative cuttings inserted or tamped 
into the ground in a manner that allows the stake to take root and 
grow), native live fascines (live branch cuttings, usually willows, 
bound together into long, cigar-shaped bundles), or brush layering 
(cuttings or branches of easily rooted tree species layered between

[[Page 66295]]

successive lifts of soil fill). Stream banks must not be stabilized 
through the use of quarried rock (rip-rap) or the use of rock baskets 
or gabion structures.
    Bridge and culvert replacement/removal projects or low head dam 
removal projects that remove migration barriers or generally allow for 
improved upstream and downstream movements of relict darters while 
maintaining normal stream flows, preventing bed and bank erosion, and 
improving habitat conditions for the species and improving habitat 
conditions for the species, if completed between June 30 and March 1.
    Transportation projects that follow best management practices that 
eliminate sedimentation, do not block stream flow, do not channelize 
streams, and provide for fish passage under a wide range of hydrologic 
conditions at stream crossings and that are done between June 30 and 
March 1.
    Projects carried out in the species' range by the U.S. Department 
of Agriculture's Natural Resources Conservation Service that do not 
alter habitats known to be used by the relict darter beyond the fish's 
tolerances and are performed between June 30 and March 1 to avoid the 
time period when the relict darter will be found within its spawning 
habitat, if such habitat is affected by the activity.
    Nothing in this 4(d) rule changes in any way the recovery planning 
provisions of section 4(f) of the Act, the consultation requirements 
under section 7 of the Act, or the ability of the Service to enter into 
partnerships for the management and protection of the relict darter. 
However, interagency cooperation may be further streamlined through 
planned programmatic consultations for the species between Federal 
agencies and the Service, where appropriate.

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). We also determine that 4(d) rules that accompany regulations 
adopted pursuant to section 4(a) of the Act are not subject to NEPA.

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 
Secretary's Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. There are no known Tribes or Tribal 
lands within the range of the relict darter.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at https://www.regulations.gov.

Authors

    The primary authors of this rule are the staff members of the Fish 
and Wildlife Service's Species Assessment Team and the Kentucky 
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 amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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


0
2. In Sec.  17.11, in paragraph (h), amend the List of Endangered and 
Threatened Wildlife by revising the entry for ``Darter, relict'' under 
Fishes to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                          Listing citations and
           Common name              Scientific name      Where listed         Status         applicable rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
             Fishes
 
                                                  * * * * * * *
Darter, relict..................  Etheostoma          Wherever found....  T              58 FR 68480, 12/27/
                                   chienense.                                             1993; 88 FR [Insert
                                                                                          Federal Register page
                                                                                          where the document
                                                                                          begins], 9/27/2023; 50
                                                                                          CFR 17.44(hh).\4d\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


0
3. Amend Sec.  17.44 by adding paragraphs (gg) and (hh) to read as 
follows:


Sec.  17.44  Special rules--fishes.

* * * * *
    (gg) [Reserved]
    (hh) Relict darter (Etheostoma chienense).
    (1) Prohibitions. The following prohibitions that apply to 
endangered wildlife also apply to relict darter. Except as provided 
under paragraph (hh)(2) of this section and Sec. Sec.  17.4 and 17.5, 
it is unlawful for any person subject to the jurisdiction of the United 
States to commit, to attempt to commit, to solicit another to commit, 
or cause to

[[Page 66296]]

be committed, any of the following acts in regard to this species:
    (i) Import or export, as set forth at Sec.  17.21(b) for endangered 
wildlife.
    (ii) Take, as set forth at Sec.  17.21(c)(1) for endangered 
wildlife.
    (iii) Possession and other acts with unlawfully taken specimens, as 
set forth at Sec.  17.21(d)(1) for endangered wildlife.
    (iv) Interstate or foreign commerce in the course of commercial 
activity, as set forth at Sec.  17.21(e) for endangered wildlife.
    (v) Sale or offer for sale, as set forth at Sec.  17.21(f) for 
endangered wildlife.
    (2) Exceptions from prohibitions. In regard to this species, you 
may:
    (i) Conduct activities as authorized by a permit under Sec.  17.32.
    (ii) Take, as set forth at Sec.  17.21(c)(2) through (4) for 
endangered wildlife.
    (iii) Take as set forth at Sec.  17.31(b).
    (iv) Take incidental to an otherwise lawful activity caused by:
    (A) Channel restoration or improvement projects that create 
natural, physically stable, ecologically functioning streams (or stream 
and wetland systems) that are reconnected with their groundwater 
aquifers and, if the projects involve known relict darter spawning 
habitat, that take place between June 30 and March 1. These projects 
can be accomplished using a variety of methods, but the desired outcome 
is a natural channel with low shear stress (force of water moving 
against the channel); bank heights that enable reconnection to the 
floodplain; a reconnection of surface and groundwater systems, 
resulting in perennial flows in the channel; riffles and pools composed 
of existing soil, rock, and wood instead of large imported materials; 
low compaction of soils within adjacent riparian areas; and inclusion 
of riparian wetlands.
    (B) Streambank stabilization projects that use bioengineering 
methods to replace preexisting, bare, eroding stream banks with 
vegetated, stable stream banks, thereby reducing bank erosion and 
instream sedimentation and improving habitat conditions for the species 
and, if the projects involve known relict darter spawning habitat, that 
take place between June 30 and March 1. Stream banks may be stabilized 
using native live stakes (live, vegetative cuttings inserted or tamped 
into the ground in a manner that allows the stake to take root and 
grow), native live fascines (live branch cuttings, usually willows, 
bound together into long, cigar-shaped bundles), or brush layering 
(cuttings or branches of easily rooted tree species layered between 
successive lifts of soil fill). Stream banks must not be stabilized 
through the use of quarried rock (rip-rap) or the use of rock baskets 
or gabion structures.
    (C) Bridge and culvert replacement/removal projects or low head dam 
removal projects that remove migration barriers or generally allow for 
improved upstream and downstream movements of relict darters while 
maintaining normal stream flows, preventing bed and bank erosion, and 
improving habitat conditions for the species, if completed between June 
30 and March 1.
    (D) Transportation projects that follow best management practices 
that eliminate sedimentation, do not block stream flow, do not 
channelize streams, and provide for fish passage under a wide range of 
hydrologic conditions at stream crossings and that are done between 
June 30 and March 1.
    (E) Projects carried out in the species' range by the Natural 
Resources Conservation Service, U.S. Department of Agriculture, that:
    (1) Do not alter habitats known to be used by the relict darter 
beyond the fish's tolerances; and
    (2) Are performed between June 30 and March 1 to avoid the time 
period when the relict darter will be found within its spawning 
habitat, if such habitat is affected by the activity.
    (v) Possess and engage in other acts with unlawfully taken 
wildlife, as set forth at Sec.  17.21(d)(2) for endangered wildlife.

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2023-20945 Filed 9-26-23; 8:45 am]
BILLING CODE 4333-15-P