66280 Federal Register / Vol. 88, No. 186 / Wednesday, September 27, 2023 / Rules and Regulations 

Federal Plan) at Subpart OOO of this 

part. 

(b) Identification of sources. The 

Existing MSW Landfills Federal Plan 

applies to each municipal solid waste 

landfill that meets the following criteria: 

(1) Commenced construction, 

reconstruction, or modification on or 

before July 17, 2014. 

(2) Accepted waste at any time since 

November 8, 1987, or has additional 

capacity for future waste deposition. 

(c) On February 6, 2023, NHDES 

Commissioner Robert R. Scott signed 

the Memorandum of Agreement 

Concerning the Delegation of Authority 

of the Federal Plan for Existing 

Municipal Solid Waste Landfills to the 

New Hampshire Department of 

Environmental Services by the United 

States Environmental Protection 

Agency. On June 27, 2023, Region 1 

Deputy Regional Administrator Karen 

McGuire signed the MoA. 

(d) The delegation became fully 

effective as of October 27, 2023. 

[FR Doc. 2023–20880 Filed 9–26–23; 8:45 am] 

BILLING CODE 6560–50–P 

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. 

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-ofcontact 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, 


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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 


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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 (km2) 

(214-square-mile (mi2)) watershed 

located within the Mississippi Valley 

Loess Plains ecoregion (Woods et al. 

2002, entire) in Fulton, Graves, and 


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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 slowflowing 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 


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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 speciesspecific 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 


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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 nonpointsource 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) 


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#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 (°C) (0.4–0.7 degrees 

Fahrenheit (°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 °C (4.1–6.1 °F) by 

2074, while precipitation models 

predict that the Bayou de Chien system 


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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 


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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

Component 

Condition 

High Moderate Low 0 

Physical Habitat ..... Silt deposition low; no extensive or 

significant habitat alterations (e.g., 

recent channelization, riparian clearing); >75% of available habitat suitable for the species.

Silt deposition moderate; habitat alterations at moderate levels—channelization or other habitat disturbance 

more widespread; 25–75% of available habitat suitable for the species.

Silt deposition extensive; habitats severely altered and recognized as impacting the species; <25% of habitats suitable for the species.Habitat unsuitable 

(species absent). 

Water Quality ......... Minimal or no known water quality 

(WQ) issues (i.e., no 303(d) streams 

impacting the species *).

WQ issues recognized and may impact species (i.e., 1 or 2 303(d) 

streams).

WQ issues prevalent within system, 

likely impacting populations (i.e., numerous 303(d) streams).

Habitat unsuitable 

(species absent). 

Mean Density (# 

darters/m2).

>0.15 .................................................... 0.05–0.15 ............................................. <0.05 .................................................... Species absent. 

Occurrence Complexity.Occupies main channel and ≥3 tributaries.Occupies main channel and maximum 

of 2 tributaries.

Occupies main channel and maximum 

of ≤1 tributary.

Species absent. 

* 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-km2 (214-mi2) 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). 


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TABLE 2—RESILIENCY, REDUNDANCY, REPRESENTATION SUMMARY FOR RELICT DARTER

Population Resiliency Redundancy Representation 

Bayou de Chien/Jackson Creek .....

Little Bayou de Chien .....................

Moderate ........

Low. 

Naturally Low—the species is a narrowly distributed 

endemic; populations appear to be separated, but 

connectivity exists within Bayou de Chien, Jackson Creek, and other large tributaries.

Low—low genetic diversity and 

low effective population size. 

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

Scenario Population 

Predicted future condition 

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 


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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 


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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 highquality or unique habitat. As a narrow 

ranging endemic, both relict darter 

populations occur within one 554-km2

(214-mi2) 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 


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does not represent unique or highquality 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, selfsustaining, 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/endangeredspecies), 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 nonFederal 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 landscapealtering 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. 


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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, 


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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 § 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 


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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 

■ 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. 

■ 2. In § 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: 

§ 17.11 Endangered and threatened 

wildlife. 

* * * * * 

(h) * * * 

Common name Scientific name Where listed Status Listing citations and applicable rules 

*******

FISHES

* * * * * * * 

Darter, relict ..................... Etheostoma chienense ... Wherever found .............. T 58 FR 68480, 12/27/1993; 88 FR [Insert Federal 

Register page where the document begins], 9/ 

27/2023; 50 CFR 17.44(hh).4d

* * * * * * * 

■ 3. Amend § 17.44 by adding 

paragraphs (gg) and (hh) to read as 

follows: 

§ 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 §§ 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 


ddrumheller on DSK120RN23PROD with RULES1
66296 Federal Register / Vol. 88, No. 186 / Wednesday, September 27, 2023 / Rules and Regulations 

be committed, any of the following acts 

in regard to this species: 

(i) Import or export, as set forth at 

§ 17.21(b) for endangered wildlife. 

(ii) Take, as set forth at § 17.21(c)(1) 

for endangered wildlife. 

(iii) Possession and other acts with 

unlawfully taken specimens, as set forth 

at § 17.21(d)(1) for endangered wildlife. 

(iv) Interstate or foreign commerce in 

the course of commercial activity, as set 

forth at § 17.21(e) for endangered 

wildlife. 

(v) Sale or offer for sale, as set forth 

at § 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 § 17.32. 

(ii) Take, as set forth at § 17.21(c)(2) 

through (4) for endangered wildlife. 

(iii) Take as set forth at § 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 § 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 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

50 CFR Part 679 

[Docket No. 230306–0065; RTID 0648– 

XD358] 

Fisheries of the Exclusive Economic 

Zone Off Alaska; Several Groundfish 

Species in the Bering Sea and Aleutian 

Islands Management Area 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Temporary rule; apportionment 

of reserves; request for comments. 

SUMMARY: NMFS apportions amounts of 

the non-specified reserve to the initial 

total allowable catch (ITAC) of Bering 

Sea (BS) Pacific ocean perch, Bering Sea 

and Aleutian Islands (BSAI) Kamchatka 

flounder, BSAI northern rockfish, BSAI 

sharks, and Central Aleutian Islands and 

Western Aleutian Islands (CAI/WAI) 

blackspotted/rougheye rockfish. This 

action is necessary to allow the fisheries 

to continue operating. It is intended to 

promote the goals and objectives of the 

fishery management plan for the BSAI 

management area. 

DATES: Effective September 26, 2023, 

through 2400 hours, Alaska local time, 

December 31, 2023. Comments must be 

received at the following address no 

later than 4:30 p.m., Alaska local time, 

October 11, 2023. 

ADDRESSES: You may submit comments 

on this document, identified by docket 

number NOAA–NMFS–2022–0094, by 

any of the following methods: 

Electronic Submission: Submit all 

electronic public comments via the 

Federal e-Rulemaking Portal. Go to 

https://www.regulations.gov and enter 

NOAA–NMFS–2022–0094 in the Search 

box. Click on the ‘‘Comment’’ icon, 

complete the required fields, and enter 

or attach your comments. 

Mail: Submit written comments to 

Gretchen Harrington, Assistant Regional 

Administrator, Sustainable Fisheries 

Division, Alaska Region NMFS. Mail 

comments to P.O. Box 21668, Juneau, 

AK 99802–1668. 

Instructions: Comments sent by any 

other method, to any other address or 

individual, or received after the end of 

the comment period, may not be 

considered by NMFS. All comments 

received are a part of the public record 

and will generally be posted for public 

viewing on https://www.regulations.gov 

without change. All personal identifying 

information (e.g., name, address, etc.), 

confidential business information, or 

otherwise sensitive information 

submitted voluntarily by the sender will 

be publicly accessible. NMFS will 

accept anonymous comments (enter ‘‘N/ 

A’’ in the required fields if you wish to 

remain anonymous). 

FOR FURTHER INFORMATION CONTACT: 

Steve Whitney, 907–586–7228. 

SUPPLEMENTARY INFORMATION: NMFS 

manages the groundfish fishery in the 

BSAI exclusive economic zone 

according to the Fishery Management 

Plan for Groundfish of the BSAI 

Management Area (FMP) prepared by 

the North Pacific Fishery Management 

Council under authority of the 

Magnuson-Stevens Fishery 

Conservation and Management Act 

(Magnuson-Stevens Act). Regulations 

governing fishing by U.S. vessels in 

accordance with the FMP appear at 

subpart H of 50 CFR part 600 and 50 

CFR part 679. 


ddrumheller on DSK120RN23PROD with RULES1