[Federal Register Volume 86, Number 219 (Wednesday, November 17, 2021)]
[Proposed Rules]
[Pages 64158-64176]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-25092]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2021-0036; FF09E22000 FXES11130900000 212]
RIN 1018-BE57


Endangered and Threatened Wildlife and Plants; Removal of the 
Okaloosa Darter From the Federal List of Endangered and Threatened 
Wildlife

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; availability of draft post-delisting monitoring 
plan.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
remove the Okaloosa darter (Etheostoma okaloosae) from the Federal List 
of Endangered and Threatened Wildlife (List) due to recovery. Our 
review of the best available scientific and commercial data indicates 
that the threats to the species have been eliminated or reduced to the 
point that the species no longer meets the definition of a threatened 
or endangered species under the Endangered Species Act of 1973, as 
amended (Act). We request information and comments from the public 
regarding this proposed rule and the draft post-delisting monitoring 
(PDM) plan for Okaloosa darters. If this proposal is finalized, 
Okaloosa darters will be removed from the List and the prohibitions and 
conservation measures provided by the Act, particularly through 
sections 7 and 9, would no longer apply to the species.

DATES: We will accept comments received or postmarked on or before 
January 18, 2022. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. Eastern Time on the closing date. We must receive requests for 
public hearings, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by January 3, 2022.

ADDRESSES: 
    Submitting Comments: You may submit comments on this proposed rule 
and draft PDM plan by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter the docket number or RIN 
for this rulemaking (presented above in the document headings). For 
best results, do not copy and paste either number; instead, type the 
docket number or RIN into the Search box using hyphens. Then, click on 
the Search button. On the resulting page, in the panel on the left side 
of the screen, under the Document Type heading, check the Proposed Rule 
box to locate this document. You may submit a comment by clicking on 
``Comment.''
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R4-ES-2021-0036; U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments by only one of the methods 
described above. We will post all comments on http://www.regulations.gov. This generally means that we will post any 
personal information you provide us (see Information Requested, below, 
for more information).
    Accessing Supporting Materials: This proposed rule, draft PDM plan, 
and supporting documents (including the Species Status Assessment (SSA) 
and references cited and the 5-year review) are available at http://www.regulations.gov under Docket No. FWS-R4-ES-2021-0036.

FOR FURTHER INFORMATION CONTACT: Lourdes Mena, Florida Chief of 
Classification and Recovery, U.S. Fish and Wildlife Service, Florida 
Ecological Services Field Office, 7915 Baymeadows Way, Jacksonville, FL 
32256-7517; telephone 904-731-3134. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal Relay 
Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

[[Page 64159]]

Executive Summary

    Why we need to publish a rule. Section 4 of the Act and its 
implementing regulations (50 CFR part 424) set forth the procedures for 
listing species, reclassifying species, or removing species from the 
Federal Lists of Endangered and Threatened Wildlife and Plants. In the 
case of any proposed rule to list, reclassify, or delist a species, we 
must publish a notice of such proposal in the Federal Register. 
Therefore, in order to remove Okaloosa darters from the List, we must 
publish a proposed rule.
    What this document does. This action proposes to remove Okaloosa 
darters from the List of Endangered and Threatened Wildlife (i.e., 
``delist'' the species) based on its recovery.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered species or a threatened species based on 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.
    The determination to delist a species must be based on an analysis 
of the same factors. Under the Act and our implementing regulations at 
50 CFR 424.11, we may delist a species if the best available scientific 
and commercial data indicate that: (1) The species is extinct; (2) the 
species does not meet the definition of an endangered species or a 
threatened species when considering the five factors listed above; or 
(3) the listed entity does not meet the statutory definition of a 
species. Here, we have determined that Okaloosa darters should be 
proposed for delisting under the Act because, based on an analysis of 
the five listing factors, it has recovered and no longer meets the 
definition of an endangered or threatened species.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments and information from the public, other concerned governmental 
agencies (including but not limited to State and Federal agencies and 
city or county governments), Native American Tribes, the scientific 
community, industry, or any other interested party concerning this 
proposed rule.
    We particularly seek comments on:
    (1) Information concerning the biology and ecology of the Okaloosa 
darter;
    (2) Relevant data concerning presence or absence of current or 
future threats to the Okaloosa darter and its habitat;
    (3) Information regarding management plans or other mechanisms that 
provide protection to the Okaloosa darter and its habitat;
    (4) Information on the potential for changes in precipitation 
levels and air and water temperatures to affect the Okaloosa darter due 
to changes in the climate or other reasons; and
    (5) The draft PDM plan and the methods and approach described.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Please note that submissions merely stating support for, or 
opposition to, the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is an endangered or a 
threatened species must be made ``solely on the basis of the best 
scientific and commercial data available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via http://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the website. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on http://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on http://www.regulations.gov.
    Because we will consider all comments and information we receive 
during the comment period, our final determinations may differ from 
this proposal. Based on the new information we receive (and any 
comments on that new information), we may conclude that the species 
should remain listed as threatened.

Public Hearing

    Section 4(b)(5) of the Act provides for a public hearing on this 
proposal, if requested. Requests must be received by the date specified 
in DATES. Such requests must be sent to the address shown in FOR 
FURTHER INFORMATION CONTACT. We will schedule a public hearing on this 
proposal, if requested, and announce the date, time, and place of the 
hearing, as well as how to obtain reasonable accommodations, in the 
Federal Register and local newspapers at least 15 days before the 
hearing. For the immediate future, we will provide these public 
hearings using webinars that will be announced on the Service's 
website, in addition to the Federal Register. The use of these virtual 
public hearings is consistent with our regulations at 50 CFR 
424.16(c)(3).

Previous Federal Actions

    On June 4, 1973, we published a final rule in the Federal Register 
(38 FR 14678) listing Okaloosa darters as endangered under the 
Endangered Species Conservation Act (Pub. L. 91-135) due to its 
extremely limited range, habitat degradation, and apparent competition 
from a possibly introduced related species, the brown darter 
(Etheostoma edwini). A 5-year status review was conducted in 2007 
(USFWS 2007, entire), and we recommended downgrading the species' 
classification to threatened as a result of substantial reduction in 
threats to the species, significant habitat restoration in most of the 
species' range, and a stable or increasing trend of Okaloosa darters in 
all stream systems. We reclassified Okaloosa darters as threatened 
under the Act on April 1, 2011, and established a rule under section 
4(d) to further provide for its conservation (76 FR 18087); the section 
4(d) rule is at 50 CFR 17.44(bb). On August 6, 2018, we initiated a 5-
year review for Okaloosa darters (83 FR 38320). This proposed rule also 
serves as our 5-year review.

Supporting Documents

    A species status assessment (SSA) team prepared an SSA report for 
Okaloosa darters (USFWS, 2019, entire). 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),

[[Page 64160]]

and our August 22, 2016, memorandum updating and clarifying the role of 
peer review of listing actions under the Act, we sought the expert 
opinions of six appropriate specialists regarding the SSA. The Service 
received two responses.

Background

    The Okaloosa darter is a small (maximum size 49 millimeters (mm), 
1.93 inches (in)) percid fish. General body coloration varies from red-
brown to green-yellow dorsally, and lighter ventrally, although 
breeding males have a bright orange submarginal stripe on the first 
dorsal fin (Burkhead et al. 1992, p. 23). The Okaloosa darter is a 
member of Order Perciformes, Family Percidae and is a distinct species 
within the genus Etheostoma (Burkhead et al. 1992, p. 23), although it 
remains uncertain as to which subgenus this species belongs (e.g., Song 
et al. 1998 pp. 348-351; Smith et al. 2014 pp. 259-260).
    The Okaloosa darter is a narrow endemic, known to occur in only the 
tributaries and main channels of six clear stream systems that drain 
into three Choctawhatchee Bay bayous (Toms, Boggy, and Rocky) in Walton 
and Okaloosa Counties in northwest Florida: Toms, Turkey, Mill, Swift, 
Deer Moss (formerly known as East Turkey or Turkey Bolton), and Rocky 
Creeks. Approximately 90 percent of the 457-square-kilometer (176-
square-mile) watershed drainage area that historically supported 
Okaloosa darters is Federal property under the management of Eglin Air 
Force Base (Eglin AFB), including about 98.7 percent of the stream 
length in the current range of the Okaloosa darter. Eglin AFB 
encompasses the headwaters of all six of these drainages, and the 
remainder of these streams flow out of Eglin AFB into the urban complex 
of the cities of Niceville and Valparaiso (USAF 2017c, p. 3-1; 76 FR 
18088, April 1, 2011).
    The Okaloosa darter's breeding season extends from late March 
through October, although it usually peaks in April. Spawning pairs 
attach small numbers of eggs to vegetation, woody debris, and root mats 
(Collete and Yerger 1962, p. 226; Burkhead et al. 1994, p. 81); 
however, little is known about larval development (Burkhead et al. 
1992, p. 26). Okaloosa darter spawn in the morning hours (Burkhead et 
al. 1992, p. 26), although courtship displays have also been observed 
late in the afternoon (Jelks 2018, pers. comm.). During courtship, a 
male will follow a single female and fertilize eggs as she deposits 
them singly among vegetation, roots, or woody detritus. Males will 
spawn with several females. As with most darters, fecundity is low 
(Burkhead et al. 1992, p. 26). A mean of 76 total ova (eggs) and 29 
mature ova were found in 201 female Okaloosa darters, although these 
numbers may underrepresent annual fecundity as their prolonged spawning 
season is an indication of fractional spawning (eggs develop and mature 
throughout the spawning season) (Ogilvie 1980, p. 4; 76 FR 18088, April 
1, 2011).
    Longleaf pine-wiregrass-red oak sandhill communities dominate the 
vegetation landscape in Okaloosa darter watersheds. These areas are 
characterized by high sand ridges where soil nutrients are low and 
woodland fire is a regular occurrence. Where water seeps from these 
hills, acid bog communities develop, consisting of sphagnum moss 
(Sphagnum sp.), pitcher plants (Sarracenia sp.), and other plants 
adapted to low-nutrient soils. In other areas, the water emerges from 
seepage springs directly into clear flowing streams where variation of 
both temperature and flow is moderated by the deep layers of sand. The 
streams support a mixture of bog moss (Mayaca fluviatilis), bulrush 
(Schoenoplectus etuberculatus), golden club (Orontium aquaticum), bur-
reed (Sparganium americanum), pondweed (Potamogeton diversifolius), 
spikerush (Eleocharis sp.), and other aquatic and emergent plants. 
Okaloosa darters typically inhabit the margins of moderate- to fast-
flowing streams where detritus (organic matter, including leaves, 
twigs, and sticks), root mats, and vegetation are present (Burkhead et 
al. 1992, p. 25; 76 FR 18088, April 1, 2011). They are rarely found in 
areas with no current or in open sandy areas in the middle of the 
stream channel. Creeks with Okaloosa darters have temperatures ranging 
from 7 to 22 degrees Celsius ([deg]C) (44 to 72 degrees Fahrenheit 
([deg]F)) in the winter to 22 to 29 [deg]C (72 to 84 [deg]F) in the 
summer (Mettee and Crittenden 1977, p. 5; Tate 2018, pers. comm.; Jelks 
2018, pers. comm). Overhead canopies range from open to fully closed 
depending on stream width and fire history (Jordan 2018, pers. comm.). 
Okaloosa darter thrive in reaches with relatively open canopies, likely 
due to either increased abundance of submerged vegetation that is used 
preferentially for spawning or increased secondary production of insect 
prey (Ingram 2018, p. 11).
    Okaloosa darter abundance has been quantified by visual census at 
multiple sites annually since 1995. Densities in 1995 averaged 1.2 
( 0.8;  1 standard deviation) Okaloosa darter 
per meter (3.28 feet) of stream length. In 2005, a rangewide survey 
estimated the species' population size at 822,500 (95 percent 
Confidence Interval 662,916 to 1,058,009). A repeat rangewide survey in 
2014 indicated that overall abundance declined by about 24 percent from 
2005 (Jordan and Jelks 2018, pp. 10-11). However, 2005 was an unusually 
good year for Okaloosa darter, and the 2014 estimates reflect some 
declines associated with dense canopy cover.
    A thorough review of the taxonomy, life history, ecology, and 
overall viability of Okaloosa darters is presented in the SSA report 
(USFWS 2019, entire; available at https://www.fws.gov/southeast/ and at 
http://www.regulations.gov under Docket No. FWS-R4-ES-2021-0036).

Recovery

    Section 4(f) of the Act directs us to develop and implement 
recovery plans for the conservation and survival of endangered and 
threatened species unless we determine that such a plan will not 
promote the conservation of the species. Under section 4(f)(1)(B)(ii), 
recovery plans must, to the maximum extent practicable, include 
objective, measurable criteria which, when met, would result in a 
determination, in accordance with the provisions of section 4 of the 
Act, that the species be removed from the List.
    Recovery plans provide a roadmap for us and our partners on methods 
of enhancing conservation and minimizing threats to listed species, as 
well as measurable criteria against which to evaluate progress towards 
recovery and assess the species' likely future condition. However, they 
are not regulatory documents and do not substitute for the 
determinations and promulgation of regulations required under section 
4(a)(1) of the Act. A decision to revise the status of a species, or to 
delist a species, is ultimately based on an analysis of the best 
scientific and commercial data available to determine whether a species 
is no longer an endangered species or a threatened species, regardless 
of whether that information differs from the recovery plan. There are 
many paths to accomplishing recovery of a species, and recovery may be 
achieved without all of the criteria in a recovery plan being fully 
met. For example, one or more criteria may be exceeded while other 
criteria may not yet be accomplished. In that instance, we may 
determine that the threats are minimized sufficiently and that the 
species is robust enough that it no longer meets the definition of an 
endangered species or a threatened species. In other cases, we may 
discover new recovery opportunities after having

[[Page 64161]]

finalized the recovery plan. Parties seeking to conserve the species 
may use these opportunities instead of methods identified in the 
recovery plan. Likewise, we may learn new information about the species 
after we finalize the recovery plan. The new information may change the 
extent to which existing criteria are appropriate for identifying 
recovery of the species. The recovery of a species is a dynamic process 
requiring adaptive management that may, or may not, follow all of the 
guidance provided in a recovery plan.
    The objective of the Okaloosa darter recovery plan is to restore 
and protect habitat and stream ecosystems so that Okaloosa darters may 
be initially downlisted (which occurred in 2011) and eventually 
delisted. The Okaloosa darter is a narrow endemic that occupies the 
unique habitats of only six stream systems. Recovery objectives are 
focused on habitats within their historical range. The recovery plan 
states that Okaloosa darters will be considered for delisting when:
    1. (a) All downlisting criteria have been met; (b) historical 
habitat of all six streams has been restored to support viable 
populations of Okaloosa darters (including degraded sections of Mill, 
Swift, and Tom Creeks); (c) erosion at clay pits, road crossings, and 
steep slopes has been minimized to the extent that resembles historical 
predisturbance condition; (d) longleaf restoration and watershed 
management practices on Eglin AFB are in effect; (e) natural, 
historical flow regimes are maintained; and (f) water quality and 
riparian habitat have been significantly improved and maintained.
    2. (a) Cooperative and enforceable agreements are in place to 
protect habitat and water quality and quantity for the historical range 
outside of Eglin AFB; and (b) management plans that protect and restore 
habitat and water quality and quantity have been effective and are 
still in place for the 90 percent of the historical range currently 
managed by Eglin AFB.
    3. Okaloosa darter populations at monitoring sites consist of two 
or more age-classes and remain stable or increasing in all six streams 
over a period of 20 consecutive years.
    4. No foreseeable threats exist that would impact the survival of 
this species (assumes military mission is compatible).

Recovery Plan Implementation

    The following discussion summarizes the recovery criteria and 
information on recovery actions that have been implemented under each 
delisting criterion.
Recovery Criteria
    Delisting Criterion #1: All reclassification criteria have been 
met. (This criterion has been met.)
    Delisting Criterion #2: Restore and protect habitat in the six 
Okaloosa darter stream watersheds.
    The Okaloosa darter is naturally restricted in distribution to six 
streams, of which about 90 percent of the basins are on Eglin AFB and 
the remaining 10 percent in the Niceville and Valparaiso municipal 
area. Because of the specific habitat requirements and limited 
distribution of the darter, habitat that is essential for spawning, 
rearing, feeding, and cover needs to be restored and protected to 
prevent the species from declining irreversibly and to recover the 
species.
    Much progress has been made towards actions identified for Okaloosa 
darters under this criterion since the species was downlisted from 
endangered to threatened. Erosion into the streams has been reduced to 
background levels, nearly all fish passage barriers on Eglin AFB have 
been removed, several projects have been completed to restore and 
reconnect stream habitat, and conservation agreements with local 
landowners have been put in place on private lands to protect stream 
and floodplain habitat. The Eglin AFB erosion control program, habitat 
restoration programs, and habitat protections agreed to by private 
landowners have improved habitat for Okaloosa darters sufficient to 
partially meet this criterion.
    Delisting Criterion #3: Erosion at clay pits, road crossings, and 
steep slopes has been minimized to the extent that resemble historical 
pre-disturbance condition. (This criterion is partially fulfilled and 
progress is ongoing.)
    Delisting Criterion #4: Longleaf restoration and watershed 
management practices on the Eglin AFB are in effect. (This criterion is 
largely fulfilled. Both longleaf and watershed management practices are 
in effect on Eglin AFB.)
    Delisting Criterion #5: Natural, historical flow regimes are 
maintained. (This criterion has been met.)
    Delisting Criterion #6: Water quality and riparian habitat have 
been significantly improved and maintained. (This criterion is 
partially fulfilled, and progress is ongoing.)
    Delisting Criterion #7: Cooperative and enforceable agreements are 
in place to protect habitat and water quality and quantity for the 
historical range outside of Eglin AFB ((2)(a), above), and management 
plans that protect and restore habitat and water quality and quantity 
have been effective and are still in place for the 90 percent of the 
historical range currently managed by Eglin AFB ((2)(b), above).
    About 90 percent of the 51,397 hectares (127,000 acres) that 
represent the drainage basins of darter streams are managed by Eglin 
AFB. Eglin AFB will continue to include management for Okaloosa darters 
in the Eglin AFB's Integrated Natural Resources Management Plan 
(INRMP), changes to which are reviewed and approved by both the Service 
and the Florida Fish and Wildlife Conservation Commission (FWC) as 
specified under the Sikes Act. Eglin AFB has no plans to remove 
management from the INRMP or limit management within Okaloosa darter 
watersheds (Tate 2020, pers. comm.). In fact, Eglin AFB is working with 
the Service to shift prescribed fire management to reduce canopy cover 
in Okaloosa darter streams to further bolster darter numbers and 
stabilize monitoring sites with observed declines. Additionally, Eglin 
AFB has placed protective buffers on Okaloosa darter streams to prevent 
land use changes and management actions that might adversely affect 
Okaloosa darters or their habitat, thus protecting 90 percent of the 
darter's watershed area from impacts (Felix 2020, pers. comm.).
    Outside the Eglin AFB boundary, the remaining 485.6 hectares (1,200 
acres) of Okaloosa darter habitat are situated in the Niceville-
Valparaiso urban complex. Okaloosa darters are found at reduced levels 
or absent from much of this area. Current stream impacts include 
erosion, non-point discharge of nutrients and pollutants, impoundment, 
alteration of flow, and culverting. Conservation agreements and habitat 
buffering on private property further prevent adverse impacts to an 
additional 3-4 percent of the potential range (Ruckel Properties 2018, 
entire). In total, 90-95 percent of the watershed area has established 
protections, and monitoring will ensure this criterion continues to be 
met.
    Delisting Criterion #8: Management plans that protect and restore 
habitat and water quality and quantity have been effective and are 
still in place for the 90 percent of the historical range currently 
managed by Eglin AFB. (This criterion is largely fulfilled through 
Eglin's 2007 INRMP.)
    Delisting Criterion #9: Okaloosa darter populations at monitoring 
sites consist of two or more age-classes and remain stable or 
increasing in all six streams over a period of 20 consecutive years.
    Monitoring for Okaloosa darters has been conducted annually at 21 
core sites distributed throughout the range since 1995. In 2005, 2014, 
and 2020,

[[Page 64162]]

expanded monitoring efforts of 58 sites were conducted to estimate the 
population size and inform the status review and species status 
assessment. Additional monitoring has been conducted to support 
specific research projects. In general, Okaloosa darter numbers 
increased in the late 1990's through early 2000's, at which time 
declines were observed at a subset of sites (Jordan and Jelks 2020). 
Multiple year classes have been recorded in each of the six watersheds 
in all years of study, regardless of declines (Jordan and Jelks 2020). 
Although declines have been identified in portions of the range, the 
majority of the declines could be associated with dense canopy cover 
limiting vegetation and primary productivity in the stream (Jordan and 
Jelks 2020). Eglin AFB natural resource managers are working to shift 
habitat management activities like prescribed fire, vegetative 
spraying, or mechanical timber stand improvement to limit excessive 
riparian growth along Okaloosa darter streams. Monitoring data will 
continue to be collected and used to assess and inform management 
actions in Okaloosa darter watersheds.
    Regardless of declines, the overall population estimate for 
Okaloosa darters was greater than 500,000 individuals in 2020 (Jordan 
and Jelks 2020) and range-wide densities generally remain above 2 
darters per meter of inhabited stream (Jordan and Jelks 2020), which is 
approximately 90% of the species' historic range. Maintaining multiple 
viable populations substantially reduces the risk of species 
extinction, and future scenario modelling suggests that resiliency and 
redundancy will persist into the foreseeable future (USFWS 2019). This 
criterion has been fully met.
    Delisting Criterion #10: No foreseeable threats exist that would 
impact the survival of this species.
    Potential future threats to the Okaloosa darter are to its habitat, 
particularly in three of the smaller basins: Mill Creek, Swift Creek, 
and Deer Moss Creek. Human activity has degraded physical and chemical 
habitat quality in these basins, though only the Deer Moss Creek 
population exhibits declines. Mill Creek is almost entirely within the 
Eglin AFB golf course, who sponsored a major stream restoration in 2007 
that nearly doubled the inhabited stream in this watershed. The golf 
course has also implemented best management practices (BMPs) for 
herbicide and pesticide application that limit impacts to Mill Creek. 
The lower portions of Swift Creek are nearly completely urbanized, but 
our models show that the planned restoration of College Pond would 
nearly double the population size. Stream restoration at College Pond 
would not only add substantial habitat to the watershed, it would also 
remove a fish passage barrier to multiple tributaries that are 
currently unoccupied by Okaloosa darters. Eglin AFB is currently 
working with USFWS, FWC, and community partners to begin engineering 
designs for this project.
    The portions of Deer Moss Creek outside Eglin AFB are currently 
subject to development pressure; however, during the FWC endangered 
species permit process, developments and other actions must show a net 
benefit to the species before approval by the State. In the case of 
Deer Moss Creek, a conservation plan was developed that prevents 
construction in all wetlands and an upland buffer, requires bridges 
that completely span all wetlands, and requires the removal of two fish 
passage barriers within the watershed, among other provisions (Ruckel 
Properties, 2014). In addition to protections from urbanization in 
lower Deer Moss Creek, the Niceville wastewater treatment facility was 
upgraded in 2010 to reduce nutrients in sprayfield effluent. Recent 
studies at Eglin AFB have found that groundwater transport in the Deer 
Moss Creek watershed is approximately 12-18 years (Landmeyer 2020, 
unpublished data), so the water quality in the stream should improve 
over time.
    Because the range of the Okaloosa darter is almost entirely on 
Federal lands, nearly all actions in this area were subject to the 
interagency cooperation requirements of section 7. Following delisting, 
the protections under section 7 will no longer apply; however, Eglin 
AFB plans to maintain protections for the Okaloosa darter by 
maintaining a buffer around Okaloosa darter streams during 
infrastructure and mission planning, developing enhanced BMPs to limit 
erosion during construction projects and continue monitoring stream 
health (Felix 2020, pers. comm.). Additionally, any action on Federal 
or private lands that impact wetlands would require permits under the 
Clean Water Act. Eglin protection and restoration of Okaloosa darter 
streams is a substantial component of natural resources management on 
Eglin AFB. Approximately 90 percent of the species' range is under the 
management of Eglin AFB; urbanization will have little to no future 
effect. Because Okaloosa darters occur in multiple stream systems, 
which provides redundancy, and no long-term threats are presently 
impacting Okaloosa darters at the species level in the foreseeable 
future, this criterion has been met.

Regulatory and Analytical Framework

    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 is an endangered species or a threatened species. The 
Act defines an endangered species as a species that is ``in danger of 
extinction throughout all or a significant portion of its range,'' and 
a threatened species as a species that is ``likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range.'' 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 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

[[Page 64163]]

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 Service 
can reasonably determine that both the future threats and the species' 
responses to those threats are likely. In other words, the foreseeable 
future is the period of time in which we can make reliable predictions. 
``Reliable'' does not mean ``certain''; it means sufficient to provide 
a reasonable degree of confidence in the prediction. Thus, a prediction 
is reliable if it is reasonable to depend on it when making decisions.
    It is not always possible or necessary to define foreseeable future 
as a particular number of years. Analysis of the foreseeable future 
uses the best scientific and commercial data available and should 
consider the timeframes applicable to the relevant threats and to the 
species' likely responses to those threats in view of its life-history 
characteristics. Data that are typically relevant to assessing the 
species' biological response include species-specific factors such as 
lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors. In the discussion of threats and the 
species' response to those threats that follows, we include, where 
possible, either a qualitative or quantitative assessment of the timing 
of the threats and species' responses to those threats.

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 
stressors to the species. The SSA report does not represent a decision 
by the Service on whether the species should be proposed for delisting. 
However, it does 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. 
In this section, we summarize the key conclusions from the SSA report; 
the full SSA report can be found on the Southeast Region website at 
https://www.fws.gov/southeast/ and at http://www.regulations.gov under 
Docket No. FWS-R4-ES-2021-0036.
    To assess the Okaloosa darter's viability, we used the three 
conservation biology principles of resiliency, representation, and 
redundancy (Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency 
describes 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 redundant and resilient 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 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.

Summary of Threats and Conservation Measures That Affect the Species

    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.
    Stressors to Okaloosa darter stem from two main sources: Land use 
and management practices on Eglin AFB and urbanization around the lower 
reaches of streams outside of Eglin AFB. Urbanization is the greatest 
threat to Okaloosa darter, as development leads to pollution, erosion, 
and sedimentation, altered water flows, and dispersal barriers through 
multiple pathways. Land use and management practices such as road 
building, timber harvesting, and fire suppression can affect abundance 
of Okaloosa darter on Eglin AFB. The effects of a changing climate, 
such as increasing stream temperatures, could become a threat to 
Okaloosa darters throughout their geographic range in the future; 
however, the degree and magnitude of any impacts are uncertain at this 
time. Impending development along Deer Moss Creek would likely be 
completed in 20 years; however, a conservation plan is in place to 
minimize impacts to Deer Moss Creek.

Sedimentation and Erosion

    Sediment loading is perhaps the primary factor continuing to impact 
Okaloosa darter. The primary sources of sediment to aquatic ecosystems 
on Eglin AFB are: accelerated streamside erosion, borrow pits (areas 
where clay, sand, or gravel are removed for use at other locations), 
developed areas, weapon test ranges, silviculture, and roads (Rainer et 
al. 2005, p. 1-1). Sedimentation can result from unpaved roads, road 
crossings, road or development projects (e.g., solar power grids), and 
can also result from poor stormwater control or runoff during heavy, 
localized rains. Even though the species has been impacted by these 
threats, the current population estimate is approximately 1.2 million 
darters across its range.
    Management for Okaloosa darters is outlined in Eglin AFB's INRMP, 
which includes specific goals and objectives to improve Okaloosa darter 
habitat, and Eglin AFB has demonstrated a commitment to recovery of the 
species. Therefore, management and other conservation actions are much 
more likely to occur on Eglin AFB than surrounding properties (USFWS 
2007, p. 5). These streams on Eglin AFB flow mostly through forested, 
natural settings, whereas off-installation, they interface mostly with 
urban and suburban areas. Eglin AFB personnel have implemented this 
effective habitat restoration program to control erosion from roads, 
borrow pits, and cleared test ranges. Since 1995, Eglin AFB personnel 
have restored 317 sites covering 196.2

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hectares (484.8 acres) that were eroding into Okaloosa darter streams, 
including borrow pits and other non-point sources (pollution created 
from larger processes and not from one concentrated point source, like 
excess sediment from a construction site washing into a stream after a 
rain) of stream sedimentation (76 FR 18090, April 1, 2011). Erosion 
into the streams has been reduced to background levels, nearly all fish 
passage barriers on Eglin AFB have been removed, several restoration 
projects have been completed to restore and reconnect stream habitat, 
and conservation agreements with local landowners (on 3-4 percent of 
potential Okaloosa darter range) have been put in place on private 
lands to protect stream and floodplain habitat (Wetland Sciences 2011, 
entire).
    Eglin AFB personnel estimate that these and other restoration 
efforts have reduced soil loss from roughly 69,000 tons/year in 
Okaloosa darter watersheds in 1994 to approximately 2,500 tons/year in 
2010 (Pizzolato 2017, pers. comm.). While soils will always be highly 
susceptible to disturbance and sedimentation and erosion could impact 
the species, habitat restoration work has improved Okaloosa darter 
habitat within the base. Improvements like bottomless culverts, bridges 
over streams, and bank restoration and revegetation have resulted in 
increased clarity of the water, stability of the channel and its banks, 
and expansion of Okaloosa darters into new areas within drainages (76 
FR 18090, April 1, 2011). Poorly designed silviculture programs can 
result in accelerated soil erosion and stream sedimentation, but Eglin 
AFB personnel have designed their program within Okaloosa darter 
habitat to avoid and minimize impacts to the aquatic ecosystems such 
that the program is not likely to adversely affect Okaloosa darters 
(USAF 2017, pp. 4-23; USFWS 2017, pp. 11-12).
    Forest and timber management in Okaloosa darter drainages is 
generally directed toward habitat management for the red-cockaded 
woodpecker or fuel reduction near military test ranges and in the urban 
interface, which involve the use of prescribed fire, mechanical or 
chemical timber stand improvement as well as traditional forestry 
practices for timber harvest and fuel-wood. Recently timbered areas may 
leave exposed sandy patches, which can be susceptible to wind erosion. 
However, erosion has been reduced to background levels; all of these 
habitat management programs are coordinated through Eglin AFB and are 
conducted in accordance with State and Federal best management 
practices (USAF 2017, p. 77, INRMP forestry component plan).

Road Development Projects

    Unpaved roads, their low-water stream crossings, and subsequent 
bank erosion probably have the greatest impact because of their 
distribution on Eglin AFB, relative permanence as base infrastructure, 
and long-term soil disturbance characteristics. The largest remaining 
source of sediment input to Okaloosa darter streams is the unpaved road 
network, which allows sediment to be washed off the road and into 
nearby streams, especially where they cross the stream itself. As of 
2005, 87 percent (4,348 km) of the roads in Eglin AFB's road network 
were unpaved, and remain so currently (Felix 2018, pers. comm.).
    Road crossings can be detrimental to Okaloosa darter depending on 
their design. Pipe culverts alter stream flow and impede movement of 
Okaloosa darter, whereas bridges and bottomless culverts do not. Of the 
153 road crossings that previously existed in Okaloosa darter 
drainages, 57 have been eliminated--28 in Boggy Bayou streams and 29 in 
Rocky Bayou streams. Although many road crossings have been removed and 
restored through road closures and restoration efforts over the last 
few years, others remain and pose a threat to Okaloosa darter and their 
habitat. For example, five road crossings in the Turkey Creek drainage 
have repeatedly exceeded State water quality standards for turbidity 
(USFWS 2017, p. 11).
    Road development projects also present potential threats that may 
negatively impact Okaloosa darter. The Mid-Bay Bridge Authority's Mid-
Bay Connector Road (Connector Road), a road constructed from the 
terminus of the Mid-Bay Bridge to SR 85 north of Niceville, was 
completed in February 2014 (USFWS 2017, p. 13). Although the Connector 
Road crosses Okaloosa darter drainages, conservation measures included 
19 stipulations to minimize impacts to darter drainages. For example, 
the project used environmentally sensitive bridge construction 
techniques and measures to minimize erosion and ground disturbance at 
each stream crossing and to maintain channel stability. Because the 
bridges were designed to maintain natural stream geomorphology and were 
built using appropriate methods to stabilize stream banks and provide 
erosion control along the stream, long-term erosion and degradation of 
Okaloosa darter habitat is not anticipated. Monitoring before, during, 
and after construction detected no significant project-related changes 
in abundance of Okaloosa darter above or below any of the new stream 
crossings (Jordan and Jelks, unpublished data). However, the project 
impacted multiple areas of Okaloosa darter streams via erosion 
associated with large storm events, and in 2012 violated erosion 
controls. One of the stream crossings required a full stream 
restoration within the project limits and downstream from the project 
area. Erosion-related issues were also reported in 2013 (USFWS 2017, p. 
13). As part of further mitigation of the Connector Road's accumulated 
negative impacts on Okaloosa darters, to date the Mid-Bay Bridge 
Authority has improved road crossings of Okaloosa darter streams at 
seven sites on Eglin AFB and at one site off of Eglin AFB. As of 
February 2019, the Mid-Bay Bridge Authority has no plans for future 
corridors; however, the existing corridor could be widened to four 
lanes if future traffic projections justify the need (USFWS 2017, p. 
13).
    The construction of the Connector Road created several relatively 
small ``orphaned'' parcels of Eglin AFB-owned property, whereby the 
road effectively separated those parcels from the natural resources 
management practices employed elsewhere over the contiguous Eglin AFB 
reservation properties. Three of these orphan parcels lie within the 
Okaloosa darter geographic range (approximately 740, 170, and 260 
acres) and surround segments of four occupied streams (Mill, Swift, 
Turkey, and Deer Moss Creeks). Eglin AFB has historically considered 
orphan parcels candidates both for leasing through enhanced use 
agreements and for real property transaction or exchange to public and 
private entities in order to maximize the effectiveness of its real 
property in supporting the United States Air Force (USAF) mission. 
Eglin AFB may consider the three parcels mentioned above for such 
transactions. However, the Eglin AFB has indicated its intent to 
coordinate with the Service on the impacts of any environmental impact 
analysis for such transactions (Felix 2018, pers. comm.).
    In 2012, the Service issued a biological opinion for widening SR 
123 from a two-lane undivided roadway to a four-lane divided roadway 
from SR 85 South to SR 85 North to the Federal Highway Administration 
(FHWA) (USFWS 2017, p. 13). The widening included new two-lane bridges 
at Toms Creek and Turkey Creek, and replacement of the culvert at the 
unnamed tributary to Turkey Creek with two single-span bridges. The 
biological opinion concluded that, while the effects of the project 
included

[[Page 64165]]

displacement, injury, and mortality to Okaloosa darter resulting from 
construction debris, equipment movement, dredge and fill activities, 
sedimentation, introduction of contaminants, and habitat alteration, it 
would not jeopardize the continued existence of the threatened Okaloosa 
darter if certain measures were implemented.
    In 2015 and 2016, multiple erosion control failures resulted in 
sediment from the project site discharging into streams occupied by 
Okaloosa darter: Toms Creek, Shaw Still Branch, Turkey Creek, and an 
unnamed tributary to Turkey Creek following storm events. The Service 
worked with the U.S. Army Corps of Engineers, FHWA, and the Florida 
Department of Transportation to develop a restoration and compensation 
plan; implementation began in 2018. The plan was designed to fully 
offset all impacts and provide a net conservation benefit to the 
species due to unforeseen, but preventable, impacts. In summer 2017, 
the Service identified additional impacts of this highway project to 
steepheads (deep ravines) outside of the initial defined Action Area 
for this project (Tate 2018, pers. comm.; USFWS 2017, pp. 13-14). 
Additionally, a working group including the Service and Eglin AFB was 
formed to develop BMPs that would prevent erosion events and that would 
be applied to base projects during site preparation and construction 
(Tate 2018, pers. comm.). The goal of this effort is to prepare BMPs 
and language/requirements to be included in the real estate leasing 
agreements, which may help ensure the species' conservation if the 
Act's protections are removed.

Stormwater Control

    Development and construction activity in residential areas outside 
of Eglin AFB and primarily in the downstream-most portion of the 
Okaloosa darter range pose a threat due to poor stormwater runoff 
control and pollution prevention measures that degrade habitat and 
sometimes create barriers to movement between basins. Although this 
threat is greater in urban areas, recent failures in erosion control 
and stormwater management on Eglin AFB highlight the importance of 
thoroughly understanding how proposed activities contribute to erosion 
and stormwater management problems and implementing practices to 
minimize those effects (USFWS 2017, p. 11).
    For example, in June 2017, a significant stormwater retention pond 
failure occurred on Eglin AFB property leased to Gulf Power and run by 
Gulf Coast Solar Center I, LLC (Coronal Energy), for a solar energy 
project. This failure caused extensive soil loss both on the leased 
site and offsite on Eglin AFB property. Okaloosa darter habitat in an 
unnamed tributary to Toms Creek was completely lost to sedimentation, 
and additional sediment is still located throughout the floodplain. 
However, this event impacted less than 0.1 percent of the estimated 
populations involved, and design changes have been made that are 
expected to fully offset all impacts and provide a net conservation 
benefit to the species due to unforeseen, but preventable, impacts 
(USFWS 2017, p. 14).

Borrow Pits

    Borrow pits were a major source of sediment loading to Okaloosa 
darter streams cited in the 1998 darter recovery plan. At that time, 29 
of 39 borrow pits located within or immediately adjacent to Okaloosa 
darter drainages had been restored. As of 2004, all borrow pits within 
Okaloosa darter drainages had been restored (59.3 ha; 146.5 ac) (USAF 
2017b, pp. 3-18; USFWS 2017, p. 11).

Pollution

    Pollution, other than sedimentation, poses a potential threat to 
darters. One stream in the darter's range, lower Turkey Creek (WBID 
495A), is on the Florida Department of Environmental Protection's 
(2018) Verified List as impaired, listing iron from a closed landfill 
as the pollutant (USFWS 2018, entire). Using aquatic insect sampling 
methods, the Service (Thom and Herod 2005, entire) found 12 sites out 
of 42 sampled within the darter's range to be impaired. One notable 
source of pollution in Shaw Still Branch and Deer Moss Creek results 
from wastewater treatment sprayfields (the Niceville-Valparaiso 
Regional Effluent Land Application Sprayfield) (USFWS 2017, pp. 12-13). 
Abundance declines from about 45 Okaloosa darter per 20 m in the 
headwaters just above the sprayfield down to 1 or fewer Okaloosa darter 
per 20 m in the remaining 4 km or so of stream downstream from the 
sprayfield (Jordan 2017, pp. 5-7; Jordan, unpublished data, Figure 8). 
The actual pollutant has yet to be determined, but impacted streams 
have high conductivity compared to the relatively sterile, ion-poor, 
and slightly acidic streams that are typical of the area and likely 
similar to streams where Okaloosa darter evolved. Contaminants found in 
the portions of Deer Moss Creek exposed to sprayfield effluent were 
shown to affect the biological processes of other species of fish in 
those streams (Weil et al. 2012, p. 185). Municipal wastewater with 
increased conductivity has been shown to negatively affect other 
species of darters (Hitt et al. 2016, entire; Fuzzen et al. 2016, 
entire).

Water Withdrawals

    Water withdrawals for human consumption in and around the range of 
Okaloosa darters are presently served by wells that tap the Floridan 
Aquifer, which is declining in the most populated areas near the coast 
(Pascale 1974, pp. 12). At this time, there is no evidence that pumping 
from that aquifer has reduced flows in darter streams (USFWS 2017, p. 
13). To the extent that the darter drainages are spring fed (by and 
large they are fed by seepage), the springs are from the shallow sand 
and gravel aquifer that is not currently used for human consumption. 
Additionally, the low permeability of the Pensacola Clay confining bed 
likely severely limits hydraulic connectivity between the two aquifers 
(Schumm et al. 1995, p. 288). As long as withdrawals from the sand and 
gravel aquifer are minimal, local human population growth should not 
adversely affect water flows in the darter drainages (USFWS 2017, p. 
13).

Effects of Climate Change

    The Intergovernmental Panel on Climate Change (IPCC) concluded that 
warming of the climate system is unequivocal (IPCC 2014, entire). 
Numerous long-term changes have been observed including changes in 
arctic temperatures and ice, and widespread changes in precipitation 
amounts, ocean salinity, wind patterns, and aspects of extreme weather 
including droughts, heavy precipitation, heat waves, and the intensity 
of tropical cyclones (IPCC 2014, entire). While continued change is 
certain, the magnitude and rate of change is unknown in many cases 
(USFWS 2017, p. 14).
    The current occupied range of the darter is restricted to 
approximately 402 km of streams in Walton and Okaloosa Counties, 
Florida. While science shows that global-scale increases in stream 
temperatures have occurred (Kaushal et al. 2010, entire; Song et al. 
2018, entire), streams within the Okaloosa darter range are seepage and 
spring-fed, and thus thought to be thermally moderated (USFWS 2017, p. 
14). However, thermal mediation varies among nearby Okaloosa darter 
streams, and streams that support Okaloosa darter are strongly affected 
by increases in air temperature (Jordan 2018, unpublished data). 
Information required to evaluate whether increased temperatures in 
streams will adversely affect Okaloosa darter is lacking; however, 
declines in abundance following the impoundment

[[Page 64166]]

of small stream reaches are likely due in part to increased 
temperatures, and the loss of darters below larger impoundments, such 
as Brandt Pond and Swift Creek, are generally assumed to be due to 
temperature change (Jordan 2018, pers. comm.). Because the distribution 
of Okaloosa darters is limited, and they cannot expand northward, 
stream temperature increases or sea level rise that would cause stream 
inundation could pose a threat to Okaloosa darter by isolating the 
populations. The National Oceanographic and Atmospheric Administration 
(NOAA) (2017, entire; NOAA Sea Level Rise Viewer 2018) projects sea 
level rise will be around 1.84 feet by year 2050 (Sweet et al. 2017, 
Intermediate High scenario). While this increase will not inundate much 
of the darter stream systems due to topography, it could isolate the 
stream systems from each other, limiting genetic exchange (Tate 2018, 
pers. comm., NOAA Sea Level Rise Viewer 2018). However, the species has 
maintained genetic exchange among populations despite current and 
historic saltwater isolation (Austin et al. 2011).

Impoundments

    Many streams within the range of Okaloosa darters have a history of 
impoundment. These impoundments were either deliberately created to 
produce recreational ponds or unintentionally formed following 
installation of a poorly designed road crossing. Culverts and other 
installations can also facilitate the creation of permanent 
impoundments by North American beavers (Castor canadensis), which take 
advantage of human-made alterations (Nicholson 2009, p. 5; Reeves et 
al. 2016, p. 1376). Okaloosa darter do not occupy impounded stream 
reaches (Mettee et al. 1976, p. 2; Nicholson 2009, p. 6) due to their 
depth and low flow rates, variable water temperatures, more 
accumulation of organic substrates, and higher numbers of predatory 
fishes than free-flowing stream reaches (Nicholson 2009, pp. 34; Reeves 
et al. 2016, p. 1376). Okaloosa darter living downstream of 
impoundments are also negatively affected, sometimes for a considerable 
distance. For instance, the roughly 3 km (60 percent) of Swift Creek 
below College Pond and roughly 2 km (100 percent) of Foxhead Branch 
below Brandt Pond currently lack Okaloosa darter (Jordan 2018, pers. 
comm.). In the absence of predators, beaver populations can become 
overpopulated (Nicholson 2009, p. 5). Eglin AFB currently traps and 
relocates nuisance beavers and removes beaver impoundments in order to 
improve stream habitats for Okaloosa darter and plans to continue this 
work indefinitely (USAF 2017, pp. 512).

Barriers to Dispersal

    All of the aforementioned threats could pose barriers to dispersal. 
Road crossings and impoundments, however, create the most obvious 
barriers, and many of these barriers have been removed. In 2011, when 
Okaloosa darters were downlisted to threatened status, 4 of the 153 
road crossings and 25 impoundments that were barriers to fish passage 
remained. A few of these road crossings were culverts with the 
downstream end perched above the stream bed, precluding the upstream 
movement of fish during normal and low-flow conditions. However, some 
of these barriers were determined to have little to no adverse 
consequence to darter habitat connectivity because they occurred on the 
outskirts of the current range or were immediately adjacent to another 
barrier or impoundment.
    To date, all but three of the problematic road crossings have been 
removed. One of these, located at the headwaters of Rocky Creek, is 
scheduled for removal in coming years. Additionally, 19 impoundments 
still exist, 11 of which are caused by beaver activity. Nine of these 
impoundments are scheduled for removal in the next 3 years. Beavers 
that remain are primarily in the headwater reaches where Okaloosa 
darters are either not present or would be in very low density. Thus, 
since the time of listing, most of the barriers to dispersal have been 
removed, and most of the problematic ones that remain are scheduled to 
be removed, contributing to improved habitat and reduced population 
fragmentation.

Canopy Closure

    Overhead canopies range from open to fully closed depending on 
stream width and fire history (Jordan 2018, pers. comm.). Okaloosa 
darters thrive in reaches with relatively open canopies, likely due to 
either increased abundance of submerged vegetation that is used 
preferentially for spawning or increased secondary production of insect 
prey (Ingram 2018, p. 11). During the past 25 years, several monitored 
stream sections have changed from open with submerged vegetation to 
closed canopies with no vegetation. Closed canopy may reduce densities 
of Okaloosa darters. Once canopy is removed, Okaloosa darter densities 
increase quickly and dramatically (USFWS 2019, p. 30). In addition to 
increased riparian density along the streams, the use of low-intensity 
fire for forest management as opposed to historically high-intensity 
wildfires could have cascading effects on the watershed through changes 
in nutrient cycling, hydrology (evapotranspiration), or simply charcoal 
buffering (changes in pH levels) of water chemistry in the creeks. The 
Eglin AFB fire management program may shift toward the use of higher 
intensity prescribed fires in the growing season along stream margins 
to control growth of canopy trees.

Invasive Species

    The introduction and colonization by nonnative invasive species 
that could compete with or prey on Okaloosa darters is a potential 
threat. The Okaloosa darter recovery plan lists competitive exclusion 
by the then-thought-to-be invasive brown darter (Etheostoma edwini) to 
be a threat to Okaloosa darters. The brown darter is native to Okaloosa 
darter watersheds (Austin, unpublished data) and is not altering the 
distribution or abundance of Okaloosa darters where they coexist (USFWS 
2019, p. 23). Flathead catfish (Pylodictus olivaris) are already 
present in the surrounding river systems, and conditions could become 
suitable for several cichlid species to successfully reproduce in 
Okaloosa darter habitat (Jelks 2018, pers. comm.). Tilapia (Oreochromis 
niloticus), for instance, are highly invasive and are well documented 
to cause local extinctions of native species through resource 
competition, predation, and habitat alteration (Canonico et al. 2005, 
pp. 467-474; Zambrano et al. 2006, pp. 1906-1909). Release of aquarium 
species also remains a possibility. While this threat is speculative 
and dependent on an intentional release of an unknown invasive species, 
introduction of a highly competitive predator could lead to severe 
population depression or potential extirpation of Okaloosa darters. 
Dispersal of an invasive species among Okaloosa darter's watersheds, 
however, would likely be limited by saltwater, giving managers time to 
take control measures within a single population. Eglin AFB and Service 
personnel have long-established invasive species monitoring programs, 
and both agencies are committed to routine monitoring, early detection, 
and control of aquatic invasive species. Early detection and targeted 
management of invasive species will minimize or eliminate this threat 
to Okaloosa darters in the future (Tate 2019, pers. comm.).

[[Page 64167]]

Summary of Factors Influencing Viability

    The vast majority of the range of Okaloosa darters is located on 
Eglin AFB, where many conservation and restoration actions have been 
successful in restoring Okaloosa darters to regions it had previously 
been extirpated from and increasing darters densities since the time of 
listing. Much progress has been made in implementing conservation 
actions since the Okaloosa darter was downlisted to threatened. For 
example, Eglin AFB has restored more than 534 acres of erosional sites 
and completed multiple stream restoration projects to reconnect 
fragmented populations. Stream erosion levels have been reduced, and 
most of the fish passage barriers have been removed. Many restoration 
projects have been completed, and conservation agreements have been 
implemented. Collectively, the habitat restoration programs have 
restored Okaloosa darter habitat, and management agreements will secure 
the habitat into the future (USAF 2017, p. 94 Wetland Sciences 2011, 
entire).
    However, portions of the Okaloosa darter's range still face 
threats, mostly from urbanization. The sedimentation, pollution and 
water quality impacts, and changes to water flow from impoundments that 
can result from urbanization can lead to a decrease in Okaloosa 
darters. In areas where there is development, either on Eglin AFB main 
base or the surrounding cities, darters decrease in abundance or 
disappear (USFWS 2019, p. 23). Darters also still face threats from 
canopy closure, accidental spills, or other severe events. However, the 
vast majority of the Okaloosa darter's range is expected to remain 
under the management of the Air Force, limiting the impacts from 
urbanization to less than 10 percent of the historical range for the 
species.
    Okaloosa darters react quickly to restoration activities. For 
instance, erosion control and other restoration activities began 
earlier in the Boggy Bayou drainages, progressing to the Rocky Bayou 
drainages (Pizzalato 2018, pers. comm.). Accordingly, darter numbers 
increased in the Boggy Bayou drainages earlier than in the Rocky Bayou 
drainages (Jordan and Jelks 2018, p. 9). Okaloosa darters have also 
been shown to quickly recolonize restored streams (Reeves et al. 2016, 
entire) and reclaimed beaver impoundments (Nicholson 2009, entire).
    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.

Current Condition

Resiliency

    For Okaloosa darters to maintain viability and withstand stochastic 
disturbance events, its populations must be sufficiently resilient, 
which is associated with population size, growth rate, and habitat 
quality. Stochastic events that have the potential to affect Okaloosa 
darter include temperature changes, drought, localized pollutants/
contaminants or other disturbances, or severe weather events such as 
hurricanes, which can impact individuals or the habitat they require 
for critical life functions such as breeding, feeding, and sheltering.
    Sufficiently resilient Okaloosa darter populations need quality 
habitat. Okaloosa darters require clear, clean, flowing water provided 
by deep layers of sand that regulate temperature and flow, with aquatic 
vegetation, root mats, leaf snags, and other substrates that provide 
cover. This habitat is maintained by land management practices on 
adjacent land that limit sedimentation and pollution. Streams that 
support Okaloosa darter should be free of impoundments created as 
human-made retention ponds, by poorly designed road crossings that 
impede flow and genetic exchange, or by beaver dams. Okaloosa darter 
also benefit from open riparian canopies that allow sunlight to reach 
the stream below (Ingram 2018, p. 11).
    For analysis purposes, we delineated resiliency units for Okaloosa 
darters based on genetic analysis and obvious barriers to dispersal. 
Genetic variation exists between the six stream systems (Austin et al. 
2011, p. 987). Because limited genetic exchange occurs between streams, 
the population in each stream is likely to be demographically 
independent; therefore, we used abundance data for each of the six 
stream systems to assess resiliency.
    Additionally, we assessed barriers to dispersal within each stream 
system that would indicate a further breakdown into additional 
populations. However, Eglin AFB has been effective in removing 
impoundments and poorly designed road crossings that served as barriers 
to dispersal, so that the remaining impoundments occur at the 
headwaters or the lower reaches of each stream, leaving each stream's 
population mostly intact, allowing genetic exchange to occur within 
each stream system. Outside of Eglin AFB, Shaw Still Branch has 
Okaloosa darter that are isolated from other Okaloosa darter in the 
upper reaches of Swift Creek by College Pond; however, the numbers of 
darters in this small stream are likely fewer than 150. Therefore, we 
considered this population separately. The watersheds of each of the 
bayous (Toms, Boggy, and Rocky) where the species has been historically 
found constitute the three resiliency units for the purposes of this 
analysis. The Toms representative unit consists only of the Toms 
population; the Boggy unit consists of the Turkey and Mill populations; 
and the Rocky unit consists of the Swift, Deer, and Rocky populations.
    Habitat metrics, such as conductivity, other water quality metrics, 
and management, influence darter presence and abundance, but due to a 
lack of explained variation within the data, no quantitative predictive 
model has been successfully used. However, numerous data exist that 
draw causal relationships between habitat metrics and darter presence 
and abundance, such that we can draw some conclusions. First, it is 
clear that Okaloosa darter does not inhabit impounded stream reaches. 
Further, when an impounded stream is restored, Okaloosa darter will 
quickly colonize the restored habitat, often at higher densities than 
initially found (Jordan and Jelks 2018, p. 29). When water conductivity 
gets too high, Okaloosa darter abundance drops (Service 2019, p. 33).
    We assess current resiliency for Okaloosa darters in terms of 
population factors, including the species' presence and density. To 
estimate a population size, we multiplied the estimated average 
abundance per meter by the estimated meters occupied (USFWS 2019, Table 
5). The average abundance was derived from annual sampling at each of 
the 21 core monitoring sites over the past 20 years. In populations 
with multiple core sites, a grand mean was

[[Page 64168]]

calculated for the entire population by averaging the long-term means 
within the population. Due to statistical constraints, population 
estimates using the expanded monitoring data from 2005 and 2014 only 
estimate the population of darters present in stream reaches between 
monitoring sites (USFWS 2019, p. 23) and do not include headwaters and 
tributary systems known to be inhabited. The calculations made during 
the SSA and used for this assessment apply the average abundance to all 
known inhabited stream reaches, generally producing a larger but more 
complete population estimate.
    Using this method, the total rangewide population estimate of 
Okaloosa darter is approximately 1,249,499 (1,010,0171,488,982) (see 
Table 1, below). The Rocky Creek population is the largest, comprising 
713,458 darters, or 57 percent of this total, followed by the Turkey 
Creek population, comprising 490,456 darters, or 39 percent. The other 
four resiliency units (Toms, Mill, Swift, and Deer Moss) together total 
only four percent of the estimate: Toms Creek has an estimated 23,099 
darters; Mill Creek, 1,317; Swift Creek, 18,810; and Deer Moss Creek, 
2,353.
    These numbers reflect a significant (40 percent) decline between 
2005 and 2014. However, the population is still significantly greater 
than when the species was originally listed. Our professional judgment 
is that the reduction was caused by an increase in the canopy cover and 
that more aggressive clearing of the canopy cover will result in 
rebounding population numbers. This conclusion is consistent with 
experimental data, in which darter populations increased within months 
after canopy removal.

                                    Table 1--Resiliency Scores for Okaloosa Darter Based on Estimated Population Size
[Population sizes <10,000 Okaloosa darters are ranked as ``low,'' populations of 10,000 to 50,000 are ``moderate,'' and values >50,000 are considered to
                                    have ``high'' resiliency. Population trends and vulnerability are also provided.]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Population trend                                                            Population
              Population                Estimated population   slope (avg. count/        Population trend              Resiliency          vulnerability
                                                                      year)                                                                     (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Toms..................................        23,099 (7,610)
Turkey................................       490,456 (90,045)
Mill..................................         1,317 (288)
Swift.................................        18,810 (9,875)
Deer Moss.............................         2,353 (1,658)
Rocky.................................       713,458 (130,006)
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the resilience analysis are as follows: Two of the 
populations (Turkey and Rocky) currently have high resiliency, two 
(Toms and Swift) are considered moderately resilient, and two (Deer 
Moss and Mill) are considered to have low resiliency.
    We classified resiliency by species' presence, density, and 
population sizes. Population sizes of <10,000 Okaloosa darters are 
considered ``low,'' 10,000 to 50,000 are ``moderate,'' and >50,000 are 
``high.'' Based on the population numbers presented above, the results 
of the resiliency analysis are as follows: Two of the populations 
(Turkey and Rocky) currently have high resiliency, two (Toms and Swift) 
have moderate resiliency, and two (Deer Moss and Mill) are considered 
to have low resiliency.

Redundancy

    Redundancy describes the ability of a species to withstand 
catastrophic events. Measured by the number of populations, their 
resiliency, and their distribution (and connectivity), redundancy 
gauges the probability that the species has a margin of safety to 
withstand or to bounce back from catastrophic local events such as 
collapse of a restored borrow pit, infestation by beavers, or spill of 
toxic chemicals that affect part or all of one population. We report 
redundancy for Okaloosa darters as the total number of populations and 
the resiliency of population segments and their distribution within and 
among representative units. Also, there are multiple populations in two 
of the stream systems.
    Six populations comprise the vast majority of the historical range 
of Okaloosa darters within the three representative units. Redundancy 
is demonstrated through the darter's presence in multiple tributaries 
within most watersheds, and representation is demonstrated through the 
genetic structure of the populations. All six extant populations 
exhibit genetic differentiation, and the species is extant across all 
three representation units. Adequate redundancy is demonstrated through 
the darter's presence in multiple tributaries within most watersheds 
encompassing its historical range.

Representation

    Representation can be characterized by genetic variability within 
the range of the species. These three representative units, each 
identified as containing unique and significant historical variation 
(Austin et al. 2011, pp. 983, 987), have not been reduced over time. 
The Toms Bayou representative unit comprises just the Toms population, 
which is currently considered moderately resilient. However, the Toms 
population is vulnerable to upstream impacts, which could affect the 
representation of this unit were a major impact to occur. The Boggy 
Bayou representative unit comprises the Turkey and Mill populations, of 
which Turkey is considered highly resilient and has low vulnerability. 
The Rocky Bayou unit comprises the Swift, Deer Moss, and Rocky 
populations, of which Swift is considered moderately resilient and 
Rocky is considered highly resilient, with low vulnerability. Given 
that each unit still contains at least one population that is 
moderately or highly resilient (>10,000 individuals), Okaloosa darters 
have sufficient genetic variability. Representation is demonstrated 
through the genetic structure of the populations.

Future Condition

    The biggest potential threat to Okaloosa darter in the future is 
development on and off Eglin AFB. Neighborhoods, roads, commercial 
structures, and associated utilities such as sprayfields are potential 
sources of sedimentation, pollution, and altered stream flow throughout 
the range of this species. Natural factors resulting from long-term 
forest management practices (e.g., prescribed fire) could also have 
potentially negative impacts on Okaloosa darters. For instance,

[[Page 64169]]

excessive canopy closure over streams might limit Okaloosa darter 
abundance by shading out aquatic vegetation preferred for spawning, 
refuge, or foraging (USFWS 2019, p. 23). The effects of canopy closure 
were built into all the future scenarios through general population 
increases or declines. For instance, in the ``Ideal Management'' 
scenario, we would expect that prescribed fire or other management 
limits excessive canopy cover and contributes to increases in darter 
numbers. The opposite would be expected in the ``Poor'' and ``Worst'' 
scenarios. Because we have not established a quantitative relationship 
between darter numbers and canopy closure, we decided to incorporate 
this factor into a general increase or decrease in populations over 
time.
    While there are several restoration activities, developments, or 
other proposed activities that have anticipated locations and 
quantifiable outcomes, specific information on the location, and 
therefore effects to Okaloosa darters, of other potential threats are 
unknown. Therefore, because it is impossible to predict the specific 
locations or impacts of future developments or other management 
decisions that could impact Okaloosa darter streams, we assess the 
future resiliency of each population based on general management and 
development scenarios. Accordingly, to assess the future viability of 
Okaloosa darters, we considered four future scenarios that account for 
some degree of future development and restoration activities, 
considering effects of whether these activities are implemented or not, 
and also considered general impacts from unknown future management or 
land use changes or impacts, at varying levels with positive or 
negative impacts to each population. For each population, we consider 
its current condition, including the length of each stream that is 
unimpounded, the length considered occupied, and the average abundance 
per meter, to assess the future viability under each of these 
scenarios.
    Please see the SSA report (USFWS 2019, entire) for a more detailed 
discussion of these considerations.
    We projected these future scenarios both over 20 years and 50 
years. Any planned restoration efforts, should they be realized, as 
well as the impending development along Deer Moss Creek, would likely 
be completed in 20 years. Okaloosa darters respond very quickly to 
habitat changes, both good and bad. Improved conditions would result in 
an increase in Okaloosa darters, possibly within the same year (Reeves 
et al. 2016, pp. 1379-1382), but areas can also lose Okaloosa darters 
equally quickly if habitat conditions worsen. In some cases where 
habitat is restored in areas without nearby Okaloosa darters, 20 years 
would be sufficient to ensure that they would recolonize that area. Not 
only would 20 years encompass several generations of Okaloosa darter, 
but it is the time period outlined in the recovery plan for delisting. 
We projected to 50 years as it is considered the outer limit that 
projections of base realignment, hydrologic cycles, or climate 
alteration may be relied upon, based on expert opinion, and will 
encompass a timeframe in which projected sea level rise as a result of 
climate change could have realized impacts.
    To account for the uncertainty in the management implications of 
some proposed actions (Deer Moss Creek development and cleanup of the 
sprayfields) and other unforeseen/unknown future conditions (future 
land management/development and accidents), we generalize the future 
stream conditions/management in four categories: status quo (current 
conditions continue), ideal, poor, and worst. The ``ideal,'' or ``best-
case,'' scenario assumes that all potential stream habitat is colonized 
at normal densities. ``Poor'' management assumes that accidents 
stemming from errors in management may occur but are unlikely to affect 
the population in the worst possible place or are unlikely to have a 
high-magnitude impact; however, over time, these accidents add up and 
eventually have a larger impact. ``Worst'' management assumes that 
accidents stemming from errors in management occur and affect the 
population in a location that will affect the largest portion of the 
stream or will be of such a magnitude to have a similar effect. In all 
long-term scenarios, we anticipate the potential negative impacts of 
climate change by applying reductions in population estimates of 0.5 
standard deviations from the current population mean abundance.
    Below we assess the future resiliency of Okaloosa darter 
populations both in the short (20-year) and long term (50-year) for the 
four different scenarios. Of the four scenarios, the status quo and the 
ideal scenario are the most likely to occur. The poor and worst 
management are the least likely to occur. Because these four scenarios 
encompass the broad changes to management, which would encompass water 
quality and render land ownership irrelevant, we model future 
resiliency based on how each scenario would affect the amount of 
occupied habitat and average abundance estimates within each 
population. Please see the SSA report for further description of the 
methodologies we used to model these scenarios and their impacts to 
Okaloosa darter.

Scenario 1: Status Quo

    In this scenario, we modeled current management coupled with both 
no restoration efforts (1a) and with restoration of the beaver dams on 
Toms Creek and College Pond on Swift Creek (1b). Under scenario 1a, 
nothing changed by way of management or restoration, meaning the 
impounded stream and abundance estimates stayed the same as is current. 
The development of Deer Moss Creek did not affect the resiliency of 
this population because the section of stream that would be developed 
is currently, and remains, unoccupied. For the species as a whole, 
population estimates did not change much in the short term but 
decreased in the long term due to a loss of potential habitat (due to 
sea level rise resulting in stream inundation) and other possible 
climate-related threats, which we modeled as a 0.5 standard deviation 
reduction for each population. Not surprisingly, the smallest and most 
fragmented populations, Mill, Deer Moss, Toms, and Swift Creeks, are 
potentially susceptible to climate change impacts alone. Habitat 
restoration in Toms and Swift Creeks would offset our modelled impacts 
from climate change. Even though saltwater inundation will fragment 
about 5 percent of the two large populations in Turkey and Rocky 
Creeks, our models exhibited minimal loss of resiliency as a result of 
climate change under this scenario.
    For the species as a whole, our modelling suggested that, under 
current management conditions, there are likely to be nearly 1 million 
Okaloosa darters beyond the 50-year timeframe. In the long term under 
this scenario, Mill Creek would lose over 30 percent of its population 
(dropping below 1,000), as would Deer Moss, and Toms Creek too, unless 
restoration occurs. Swift Creek would lose almost 60 percent of its 
population unless habitat restoration occurs, but if restoration 
occurs, the population would more than double in the short term and 
still increase by nearly 60 percent in the long term. Saltwater 
inundation in the long term would cause the Rocky, Turkey, and Swift 
populations to split into three streams each. While Rocky and Turkey 
would see about 5 percent of their populations cut off from the main 
segment, the inundation of Swift Creek would also cut off that 
population from the current location in the absence of restoration 
efforts. With no restoration,

[[Page 64170]]

we can expect that 70 percent of the population in Swift Creek will be 
above College Pond in Swift Creek, with fewer than 100 in Shaw Still 
Branch, although neither of these populations are unlikely to remain at 
all in 50 years. With restoration, about 83 percent of the population 
would remain in the Swift Creek population and about 17 percent in a 
Shaw Still Branch population, with likely no dispersal between them 
(see Table 2, below). Due to the continued impacts of the urbanization 
in the watershed within the city of Niceville, we estimated population 
sizes as if inhabited under moderate management conditions (long-term 
average minus one standard deviation). Sanders Branch would remain 
unoccupied.

                         Table 2--Scenario 1 of Management for Okaloosa Darter Recovery
 [Total stream lengths that would be unimpounded, the occupied meters and the percent that represents, abundance
  estimates per meter, and the projected population size, both with and without restoration efforts on Toms and
     Swift Creeks, in both the short term and long term. Scenario 1b shown for Toms (r) and Swift (r) assume
                             restoration of uninhabited portions of the watershed.]
----------------------------------------------------------------------------------------------------------------
                                                       Total
                                                    unimpounded    Occupied (m)     Abundance/m     Population
                                                    streams (m)                                        size
----------------------------------------------------------------------------------------------------------------
Short Term:
    Toms........................................          14,936          11,300             2.0          23,011
    Turkey......................................         150,040         147,911             3.3         486,243
    Mill........................................           1,993             846             1.6           1,317
    Swift.......................................          21,130           5,292             3.5          18,631
    Deer Moss...................................           8,396           5,780             0.4           2,354
    Rocky.......................................         282,068         276,683             2.6         707,791
    Toms (r)....................................          16,336          12,360             2.0          25,167
    Swift (r)...................................          22,276          14,767             3.5          46,622
Long Term:
    Toms........................................          14,111           9,265             1.7          15,759
    Turkey......................................         149,063         132,041             3.0         394,227
    Mill........................................           1,993             647             1.4             896
    Swift.......................................          19,533           2,939             2.6           7,631
    Deer Moss...................................           7,981           4,696             0.3           1,239
    Rocky.......................................         280,096         246,739             2.3         573,683
    Toms (r)....................................          15,511          11,736             1.7          19,960
    Swift (r)...................................          20,679          11,031             2.6          20,509
----------------------------------------------------------------------------------------------------------------

Scenario 2: Ideal Restoration, Good Management

    This scenario represented the highest population size that the 
species could attain. Under this scenario, all impoundments were 
removed, and management removed most existing threats, increasing the 
occupied lengths of each stream to almost all of the inhabitable area. 
In other words, we modelled the potential population for all streams as 
if they were completely free-flowing by applying our current population 
estimates to the entire potential length of stream habitat in the 
watershed. This scenario represented the ``best case scenario'' for the 
species. Because of this, we modelled an expected population expansion 
of 1.0 standard deviation from the current mean abundance for each 
population. As expected, short-term estimates increased for all 
populations, with the highest relative increases in fragmented 
populations (Swift and Toms) or those impaired by urbanization (Deer 
Moss and Mill). Because we apply the same negative influence of climate 
change to the long-term models in this scenario, the long-term 
population estimates are dampened but still increasing in the four 
smaller populations with a very slight (<1 percent) reduction in Turkey 
and Rocky Creeks due to fragmentation and saltwater inundation. Under 
this scenario, our model indicated there will be more than 1.3 million 
Okaloosa darters and increased resiliency in all of the smaller 
populations, even when negative impacts of climate change are applied 
in the long term.
    In the short term, the population would increase for all stream 
systems, although by a much higher percent in Mill and Swift than in 
Rocky and Turkey Creeks. In the long term, all populations except 
Turkey and Rocky still see an increase from current conditions, though 
not quite as large. Turkey and Rocky would decrease slightly from the 
current situation (see Table 3, below). Saltwater inundation in the 
long term would cause the Rocky, Turkey, and Swift stream systems to 
split into three streams each. While Rocky and Turkey would see about 5 
percent of their populations cut off from the main segment, the 
inundation of Swift Creek in the long term, given ideal restoration and 
management, would split the population such that about 15 percent would 
be cut off into a Shaw Still Branch population, and about 11 percent 
would be cut off into a Sanders Branch population.

                         Table 3--Scenario 2 of Management for Okaloosa Darter Recovery
 [Total stream lengths that would be unimpounded, the occupied meters and the percent that represents, abundance
     estimates per meter, and the projected population size in both the short term and long term. Saltwater
            inundation in the long term causes the Swift stream systems to split into three streams.]
----------------------------------------------------------------------------------------------------------------
                                                       Total
                                                    unimpounded    Occupied (m)     Abundance/m     Population
                                                    streams (m)                                        size
----------------------------------------------------------------------------------------------------------------
Short Term:

[[Page 64171]]

 
    Toms........................................          18,510          18,247             2.7          49,397
    Turkey......................................         152,692         150,525             3.9         585,687
    Mill........................................           4,555           4,490             1.9           8,520
    Swift.......................................          24,510          24,162             5.4         129,717
    Deer Moss...................................           8,396           8,277             0.7           5,746
    Rocky.......................................         282,731         278,719             3.0         842,921
Long Term:
    Toms........................................          17,685          15,666             2.4          37,153
    Turkey......................................         151,715         134,390             3.6         482,352
    Mill........................................           4,555           4,035             1.7           6,968
    Swift.......................................          22,913          14,816             4.4          65,852
                                                                           3,146             4.4          13,982
                                                                           2,334             4.4          10,374
    Deer Moss...................................           7,981           7,070             0.6           3,894
    Rocky.......................................         280,759         248,699             2.8         694,169
----------------------------------------------------------------------------------------------------------------

Scenario 3: Poor Management

    To model what the future effect of poor management decisions, 
developments, or other habitat impacts would be in terms of a decrease 
in average Okaloosa darter abundance per meter, we considered the 
configuration (or geography) of each stream system for each population. 
In streams that are complex (have many branching tributaries) or are 
generally large, a severe negative impact (such as a chemical spill or 
source of chronic sedimentation) at any of the headwaters would be more 
likely to impact a smaller percentage of the population compared to a 
similar impact in the headwaters of a low-complexity (few tributaries) 
or small stream system. For scenarios 3 and 4, we first assessed the 
effects of an impact that might occur at the worst possible placement 
within each watershed by finding the longest length of stream that 
could be affected by a major impact at the headwaters; in other words, 
the longest possible downstream distance that could be affected by a 
single upstream impact. We calculated this distance for each stream 
(USFWS 2019, Figure 14) and then took that distance and calculated the 
percent of the total unimpounded streams it would affect (USFWS 2019, 
Table 7). This percent represents the maximum percent of the stream 
system that could be affected by one management decision or 
development. In real-world terms, if one of the outlying airfields that 
are located in the upper reaches of these stream systems (USFWS 2019, 
Figure 14) were to be reactivated for military or other uses, the 
amount of stream impacted could come close to or meet these estimates 
of ``largest percent affected.''
    For both the ``Poor'' and ``Worst'' management scenarios, we used 
this ``largest percent affected'' to model declines in Okaloosa darter 
abundances based on whether management was considered ``poor'' or 
``worst,'' and whether we were assessing the scenario in the long or 
short term (USFWS 2019, Table 8).
    For management that was ``poor,'' looking at the short term, we 
considered a management decision or set of decisions or impacts that 
would decrease the average abundance by 1 standard deviation across 
this ``largest percent affected'' (this percent of the occupied 
meters). The remainder of the occupied stream length stayed at current 
Okaloosa darter abundances. In the long term, we proposed that 
management impacts could continue to affect these streams either in 
unfortunate locations or in great magnitude and, coupled with unknown 
impacts of climate change and the associated warming over that time 
span, will decrease all abundance estimates an additional 0.5 standard 
deviation (USFWS 2019, Table 8). As with ``Status Quo,'' we modeled 
poor management coupled with either no restoration efforts or removal 
of beaver dams on Toms Creek and restoration of College Pond on Swift 
Creek.
    Under this scenario (see Table 4, below), all population sizes 
decreased. In the long term, the Swift population dropped below 10,000 
individuals unless College Pond is restored, in which case the 
population almost doubled in the short term and still maintained 15 
percent more than current in the long term. In the long term, the Swift 
Creek population dropped below 10,000 individuals without restoration, 
and the populations in both Deer Moss and Mill Creeks dropped below 
1,000 individuals. Even so, long-term resiliency in Toms, Turkey, 
Swift, and Rocky Creeks remained relatively unchanged from the ``Status 
Quo'' models.

                         Table 4--Scenario 3 of Management for Okaloosa Darter Recovery
 [Total stream lengths that would be unimpounded, the occupied meters and the percent that represents, abundance
  estimates per meter, and the projected population size, both with and without restoration efforts on Toms and
                              Swift Creeks, in both the short term and long term.]
----------------------------------------------------------------------------------------------------------------
                                                       Total
                                                    unimpounded    Occupied (m)   Avg. Abundance/   Population
                                                    streams (m)                          m             size
----------------------------------------------------------------------------------------------------------------
Short Term:
    Toms........................................          14,936          11,300             1.8          20,333

[[Page 64172]]

 
    Turkey......................................         150,040         147,911             3.2         474,298
    Mill........................................           1,993             846             1.3           1,057
    Swift.......................................          21,130           5,292             3.1          16,321
    Deer Moss...................................           8,396           5,780             0.2           1,075
    Rocky.......................................         282,068         276,683             2.5         692,277
    Toms (r)....................................          16,336          12,360             1.8          21,913
    Swift (r)...................................          22,276          14,767             2.8          41,688
Long Term:
    Toms........................................          14,111           9,265             1.5          13,563
    Turkey......................................         149,063         132,041             2.9         383,564
    Mill........................................           1,993             647             1.1             698
    Swift.......................................          19,533           2,939             2.2           6,348
    Deer Moss...................................           7,981           4,696             0.1             284
    Rocky.......................................         280,096         246,739             2.3         559,848
    Toms (r)....................................          15,511          10,184             1.4          14,640
    Swift (r)...................................          20,679          13,290             1.9          25,238
----------------------------------------------------------------------------------------------------------------

Scenario 4: Worst Management

    This scenario is very pessimistic. We considered a management 
decision or set of decisions or impacts that would decrease the average 
abundance by 2 standard deviations across the ``largest percent 
affected,'' described above. The remainder of the occupied stream 
length in Scenario 4 was then considered to be occupied at the ``poor'' 
Okaloosa darter abundances (a reduction of 1 standard deviation). As 
with other scenarios, we modeled climate change impacts as an 
additional reduction of 0.5 standard deviations from the long-term mean 
and considered the impact of restoration in Toms and Swift Creeks in a 
separate model.
    This is the only scenario where we modelled an extirpation. All 
populations were reduced by at least 20 percent, even in the short term 
(see Table 5, below). Under this scenario, Mill and Deer Moss Creek 
dropped below 1,000 individuals in the short term, and Deer Moss Creek 
became extirpated in the long term. We estimated a population decline 
in Toms Creek to approximately half the population estimate of the 
``Status Quo'' scenario. Our model projected that Swift Creek could 
drop to approximately one quarter the population anticipated under the 
``Status Quo''; however, the restoration of College Pond would prevent 
this population from dropping below 10,000 individuals in the short 
term and more than quadruple the population estimate in the long term. 
The Turkey and Rocky populations would maintain high resiliency, above 
300,000 individuals, even in the long term.

                         Table 5--Scenario 4 of Management for Okaloosa Darter Recovery
 [Total stream lengths that would be unimpounded, the occupied meters and the percent that represents, abundance
  estimates per meter, and the projected population size, both with and without restoration efforts on Toms and
                              Swift Creeks, in both the short term and long term.]
----------------------------------------------------------------------------------------------------------------
                                                       Total
                                                    unimpounded    Occupied (m)   Avg. Abundance/   Population
                                                    streams (m)                          m             size
----------------------------------------------------------------------------------------------------------------
Short Term:
    Toms........................................          14,936          11,300             1.1          12,752
    Turkey......................................         150,040         147,911             2.6         385,027
    Mill........................................           1,993             846             0.9             769
    Swift.......................................          21,130           5,292             1.3           6,760
    Deer Moss...................................           8,396           5,780             0.0             159
    Rocky.......................................         282,068         276,683             2.0         563,304
    Toms (r)....................................          16,336          12,360             1.1          13,622
    Swift (r)...................................          22,276          14,767             1.0          15,377
Long Term:
    Toms........................................          14,111           9,265             0.8           7,348
    Turkey......................................         149,063         132,041             2.3         303,870
    Mill........................................           1,993             647             0.7             478
    Swift.......................................          19,533           2,939             0.6           1,680
    Deer Moss...................................           7,981           4,696             0.0               0
    Rocky.......................................         280,096         246,739             1.8         444,833
    Toms (r)....................................          15,511          11,736             0.8           8,998
    Swift (r)...................................          20,679          13,290             0.5           6,192
----------------------------------------------------------------------------------------------------------------


[[Page 64173]]

Future Resiliency

    Our projections of how resiliency will change in the future are 
based on the completion or success of specific restoration efforts, 
nonspecific changes to the management of Okaloosa darter streams or 
other unforeseen impacts, and the effects of climate change, including 
unknown effects to the streams from temperature increases, drought, 
frequent or heavy rainfalls, or invasive species. Our models showed 
population increases only under ``ideal restoration--good management,'' 
with the exception of restoration efforts on Swift Creek, which 
increase the population even under the ``poor'' management scenario. We 
also took a pessimistic approach to climate change impacts by applying 
population reductions to all populations in the long-term models. 
Accordingly, population numbers declined in the long-term models across 
all stream systems in the absence of future management efforts. Both 
Mill Creek and Deer Moss Creek remained at low resiliency and decreased 
to fewer than 1,000 individuals or became extirpated in the long term 
under the ``poor'' and ``worst'' scenarios. Toms Creek maintained a 
moderate resiliency in all but the ``worst'' scenario. Swift Creek 
would see a huge benefit from the removal of beaver impoundments in 
College Pond, which even under ``poor'' management conditions, would 
almost double its population size in the short term. In the long term, 
restoring College Pond resulted in the most robust population gains, 
roughly quadrupling population estimates under ``poor'' and ``worst'' 
scenarios. Even under the worst projected management or impact 
scenario, the estimated sizes of Rocky and Turkey populations did not 
drop below 300,000, and resiliency in these populations remained 
exceptionally high.
    In general, in our scenarios, the larger populations were more 
resilient and were more likely than small populations to maintain 
resiliency in the future. The Deer Moss population is considered to 
have a low resiliency in comparison to the other populations; however, 
even under ideal conditions, our models suggested that this population 
can increase to only about 4,000 individuals, which remains below our 
designation of moderate resiliency. So, even under ``ideal'' 
conditions, this population will always have low resiliency. 
Regardless, the Deer Moss Creek population has persisted over time, 
even with a much lower resiliency than the other populations. When 
comparing model outcomes to the most likely future scenario, ``status 
quo,'' we do not see shifts in resiliency categorization for any of the 
populations. Only under the ``worst'' scenario were the resiliency for 
Toms and Swift Creeks depressed, indicating that the two large 
populations, Turkey and Rocky, should maintain high to very high 
resiliency in perpetuity. From a population standpoint, a reduction of 
2.5 standard deviations from the long-term mean is massive and highly 
unlikely, indicating the ``worst'' scenario is a depiction of a truly 
catastrophic decline. Even under this scenario, five of the six 
populations remain. At the species level, Okaloosa darters exhibit 
moderate to high resiliency even under the worst-case scenario.

Future Redundancy

    Determined by the number of populations, their resiliency, and 
their distribution (and connectivity), redundancy describes the 
probability the species has a margin of safety to withstand or recover 
from catastrophic events (such as a rare destructive natural event or 
episode involving many populations). Okaloosa darters have a 
constrained range, limited to just six populations in six streams, and 
redundancy is naturally low. However, the Okaloosa darter inhabits its 
historical range almost completely, exhibiting documented resiliency to 
natural phenomena such as hurricanes and drought (USFWS 2019, p. 23).
    Four of the populations, the ones with the lowest current 
resiliency, are considered highly vulnerable to catastrophic events due 
to their stream configuration. We determined the ``largest percent 
affected'' in Mill Creek to be 90 percent (USFWS 2019, Table 7). Thus, 
a major impact like a toxic chemical spill in the upper watershed could 
result in drastic population declines. Further, climate change could 
have consequences that make the streams uninhabitable to Okaloosa 
darters; temperature rise is one potential threat, but other impacts 
are possible. Invasive species could also extirpate an entire 
population were a highly competitive predator to be introduced; 
tilapia, for instance, are highly invasive and are well documented to 
cause local extinctions of native species through resource competition, 
predation, and habitat alteration (Canonico et al. 2005, pp. 467-474; 
Zambrano et al. 2006, pp. 1906-1909). Given the species' limited range, 
catastrophic events or the invasion of a nonnative species or steady 
changes such as increased stream temperatures due to climate change 
could impact one or more populations. Even so, our modeling resulted in 
only one population completely failing in the long term under our 
``worst'' management scenario, and that scenario assumed drastic 
declines across all six populations. Thus, loss of redundancy is 
unlikely in all but the most extreme circumstances. Accordingly, we do 
not expect Okaloosa darter viability to be characterized by a loss in 
redundancy unless management fails dramatically in the coming years or 
a major impact occurs.

Future Representation

    All representative units are predicted to retain the same number of 
populations at least 50 years into the future, except in the scenario 
where management is particularly bad (Worst scenario). In the Worst 
scenario, the Deer Moss population becomes extirpated and the Mill 
population would experience heavy declines. In both the Poor and Worst 
scenarios, each representative unit will have populations with 
decreased resiliency, both within the next 20 years (short term) and 
next 50 years (long term); however, even under the Worst scenario, the 
two large populations (Turkey Creek and Rocky Creek) will ensure 
continued resiliency for those populations. The Toms Creek population, 
being the only population in its representative unit, will see 
decreased resiliency in the short term in all scenarios except those 
with current or ideal management and in the long term, all scenarios 
except those with ideal management.

Determination of Species Status

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

[[Page 64174]]

six historical watersheds. Populations in two of those watersheds are 
currently highly resilient, two are moderately resilient, and two have 
low resiliency. While the populations have been affected by 
impoundments, urbanization (on the lower ends of the streams), and land 
use impacts (e.g., sedimentation), current population estimates show 
approximately one million darters across its range. Redundancy is 
demonstrated through the darters' presence in multiple tributaries 
within most watersheds, and representation is demonstrated through the 
genetic structure of the populations. All six extant populations 
exhibit genetic differentiation, and the species is extant across all 
three representative units. Overall, the populations are robust. 
Because approximately 90 percent of the species' range is under the 
management of Eglin AFB, urbanization will have little to no future 
effect. Okaloosa darters occur in multiple stream systems, which 
provides redundancy, and no long-term threats are presently impacting 
Okaloosa darters at the species level. Accordingly, we conclude that 
the species is not currently in danger of extinction, and thus does not 
meet the definition of an endangered species, throughout its range.
    In considering whether the species continues to meet the definition 
of a threatened species (likely to become an endangered species within 
the foreseeable future) throughout its range, we identified the 
foreseeable future for Okaloosa darters to be 20-50 years based on our 
ability to reliably predict the species' response to current and future 
threats. Over 90 percent of the darter's range is located on Eglin AFB 
and will continue to benefit from the conservation protections 
resulting from the Eglin AFB INRMP. Overall, while there may be some 
loss of resiliency due to climate change, in all but the worst-case 
scenario, all extant populations will remain. Redundancy will remain 
the same except under the worst-case scenario, as will representation. 
Under all four management scenarios, two darter populations (Turkey 
Creek and Rocky Creek) are expected to continue to be highly resilient. 
Toms Creek will continue to be moderately resilient in all but the 
worst-case scenario, in which case its resilience will fall to low. The 
currently uninhabited tributaries in the Swift Creek watershed will 
continue to be isolated due to sea level rise, and without restoration, 
Swift Creek itself will be the only occupied tributary in this 
population; however, the upper Swift Creek population will continue to 
serve as a source for recolonization if restoration occurs. Deer Moss 
Creek is the only population with potential for extirpation, and then 
only under the worst-case scenario. Further, this population exhibits 
low resiliency even under ``ideal'' conditions, and its extirpation 
would not compromise the resiliency of the Rocky Creek representative 
unit. In other words, while some populations may decline or even become 
extirpated under the two negative scenarios, under all scenarios 
Okaloosa darters will exhibit sufficient resiliency, redundancy, and 
representation to maintain viability for the foreseeable future. 
Accordingly, we conclude that the species is not likely to become in 
danger of extinction in 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. Having determined that the Okaloosa darter is not in danger 
of extinction or likely to become so in the foreseeable future 
throughout all of its range, we now consider whether it may be in 
danger of extinction or likely to become so in the foreseeable future 
in a significant portion of its range--that is, whether there is any 
portion of the species' range for which it is true that both (1) the 
portion is significant; and (2) the species is in danger of extinction 
now or likely to become so in the foreseeable future in that portion. 
Depending on the case, it might be more efficient for us to address the 
``significance'' question or the ``status'' question first. We can 
choose to address either question first. Regardless of which question 
we address first, if we reach a negative answer with respect to the 
first question that we address, we do not need to evaluate the other 
question for that portion of the species' range.
    In undertaking this analysis for Okaloosa darters, we chose to 
address the status question first--we considered information pertaining 
to the geographic distribution of both the species and the threats that 
the species faces, to identify any portions of the range where the 
species is endangered or threatened. We examined whether any threats 
are geographically concentrated in any portion of the species' range at 
a biologically meaningful scale. It is important to note at the outset 
that this is a narrow endemic with a naturally limited range. We 
examined the following threats: Land use and management practices on 
Eglin AFB and urbanization around the lower reaches of streams outside 
of Eglin AFB. Urbanization is the greatest threat to Okaloosa darter, 
as development leads to pollution, erosion, and sedimentation, altered 
water flows, and dispersal barriers through multiple pathways. The 
threats of sea level rise and urbanization are present in the southern 
portion of each population, so they are not concentrated on any one 
population.
    As described above, no threats are concentrated in any portion of 
that range. Although the main threat, urbanization, is present only in 
the downstream portion of the watersheds--five of the six watersheds 
pass through the cities of Niceville and Valparaiso before emptying 
into Choctawhatchee Bay--these urban impacts are not concentrated on 
any one population. Because the majority of the watersheds are forested 
and geology is consistent throughout the Okaloosa darter's range, the 
effects of canopy closure and erosion should be similar across all six 
watersheds.
    We found no concentration of threats in any portion of the Okaloosa 
darter's range at a biologically meaningful scale. Therefore, no 
portion of the species' range can provide a basis for determining that 
the species is in danger of extinction now or likely to become so in 
the foreseeable future in a significant portion of its range, and we 
find that the species is not in danger of extinction now or likely to 
become so within the foreseeable future in any significant portion 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 available scientific and commercial 
information indicates that the Okaloosa darter does not meet the 
definition of an endangered species or a threatened species in 
accordance with sections 3(6) and 3(20) of the Act. Therefore, we 
propose to delist the Okaloosa darter from the Federal List of 
Endangered and Threatened Wildlife.

Effects of This Proposed Rule

    This proposal, if finalized, would revise 50 CFR 17.11(h) and 
17.44(bb) by removing Okaloosa darter from the Federal List of 
Endangered and Threatened Wildlife and removing the section 4(d) rule 
for this species. The prohibitions and conservation measures

[[Page 64175]]

provided by the Act, particularly through sections 7 and 9, would no 
longer apply to this species. Federal agencies would no longer be 
required to consult with the Service under section 7 of the Act in the 
event that activities they authorize, fund, or carry out may affect 
Okaloosa darter. However, approximately 90 percent of the 457-square-
kilometer (176-square-mile) watershed drainage area that historically 
supported Okaloosa darters is Federal property under the management of 
Eglin AFB, and about 98.7 percent of the stream length in the current 
range of Okaloosa darters is within the boundaries of Eglin AFB.
    As discussed above, Eglin AFB encompasses the headwaters of all six 
of these drainages. Benefits from the conservation protections will 
continue because the Air Force will maintain its INRMP for the benefit 
of other listed species, such as the red-cockaded woodpecker (USAF 
2017c, p. 3-1; (76 FR 18088, April 1, 2011). Thus, the INRMP will 
continue to provide for the conservation of Okaloosa darters even if 
the species is delisted. Because the Service is required to approve 
INRMPs every 5 years, we will be able to ensure that this INRMP 
continues to protect Okaloosa darters into the future. There is no 
critical habitat designated for this species, so there would be no 
effect to 50 CFR 17.95.

Post-Delisting Monitoring

    Section 4(g)(1) of the Act requires us, in cooperation with the 
States, to implement a monitoring program for not less than 5 years for 
all species that have been delisted due to recovery. Post-delisting 
monitoring (PDM) refers to activities undertaken to verify that a 
species delisted remains secure from the risk of extinction after the 
protections of the Act no longer apply. The primary goal of PDM is to 
monitor the species to ensure that its status does not deteriorate, and 
if a decline is detected, to take measures to halt the decline so that 
proposing it as a threatened or endangered species is not again needed. 
If at any time during the monitoring period data indicate that 
protective status under the Act should be reinstated, we can initiate 
listing procedures, including, if appropriate, emergency listing.
    Section 4(g) of the Act explicitly requires that we cooperate with 
the States in development and implementation of PDM programs. However, 
we remain ultimately responsible for compliance with section 4(g) and, 
therefore, must remain actively engaged in all phases of PDM. We also 
seek active participation of other entities that are expected to assume 
responsibilities for the species' conservation after delisting.
    We will coordinate with other Federal agencies, State resource 
agencies, interested scientific organizations, and others as 
appropriate to develop and implement an effective PDM plan for the 
Okaloosa darter. The PDM plan will build upon current research and 
effective management practices that have improved the status of the 
species since listing. Ensuring continued implementation of proven 
management strategies that have been developed to sustain the species 
will be a fundamental goal for the PDM plan. The PDM plan will identify 
measurable management thresholds and responses for detecting and 
reacting to significant changes in Okaloosa darter numbers, 
distribution, and persistence. If declines are detected equaling of 
exceeding these thresholds, the Service, in combination with other PDM 
participants, will investigate causes of the declines. The 
investigation will be to determine if the Okaloosa darter warrants 
expanded monitoring, additional protection under the Act.
    We are proposing to delist Okaloosa darters based on all six extant 
populations exhibiting genetic differentiation and the species is 
extant across all three representation units. Overall, the populations 
are robust. Because approximately 90 percent of the species' range is 
under the management of Eglin AFB, urbanization will have little to no 
future effect. The Okaloosa darter occurs in multiple stream systems, 
and no long-term threats are presently impacting the Okaloosa darter at 
the species level. Since delisting would be, in part, due to 
conservation actions taken by stakeholders, we have prepared a draft 
PDM plan for Okaloosa darters. The draft PDM plan discusses the current 
status of the taxon and describes the methods proposed for monitoring 
if we delist the taxon. The draft PDM plan: (1) Summarizes the status 
of Okaloosa darters at the time of proposed delisting; (2) describes 
frequency and duration of monitoring; (3) discusses monitoring methods 
and potential sampling regimes; (4) defines what potential triggers 
will be evaluated to address the need for additional monitoring; (5) 
outlines reporting requirements and procedures; (6) proposes a schedule 
for implementing the PDM plan; and (7) defines responsibilities. It is 
our intent to work with our partners towards maintaining the recovered 
status of Okaloosa darters. We will seek public and peer reviewer 
comments on the draft PDM plan, including its objectives and procedures 
(see FOR FURTHER INFORMATION CONTACT and Information Requested, above), 
with the publication of this proposed rule.
    Concurrent with this proposed delisting rule, we announce the draft 
PDM plan's availability for public review at http://www.regulations.gov 
under Docket Number FWS-R4-ES-2021-0036. The Service prepared this 
draft PDM plan in coordination with Eglin AFB, based largely on 
monitoring methods developed by the U.S. Geological Survey and Loyola 
University New Orleans (USFWS 2021, p. 5). The Service designed the PDM 
plan to detect substantial changes in habitat occupied by Okaloosa 
darter and declines in Okaloosa darter occurrences with reasonable 
certainty and precision. It meets the minimum requirement set forth by 
the Act because it monitors the status of Okaloosa darter using a 
structured sampling regime over a 10-year period.
    Copies can also be obtained from the Service's Panama City 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT). 
We anticipate finalizing this plan, considering all public comments, 
prior to making a final determination on the proposed delisting rule.

Required Determinations

Clarity of the Proposed Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (a) Be logically organized;
    (b) Use the active voice to address readers directly;
    (c) Use clear language rather than jargon;
    (d) Be divided into short sections and sentences; and
    (e) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in ADDRESSES. To better help 
revise the rule, your comments should be as specific as possible. For 
example, you should tell us the numbers of the sections or paragraphs 
that are unclearly written, which sections or sentences are too long, 
the sections where you feel lists or tables would be useful, etc.

National Environmental Policy Act

    We have determined that we do not need to prepare an environmental 
assessment or environmental impact statement, as defined in the 
National Environmental Policy Act (42 U.S.C.

[[Page 64176]]

4321 et seq.), in connection with regulations adopted pursuant to 
section 4(a) of the Endangered Species Act. We published a notice 
outlining our reasons for this determination in the Federal Register on 
October 25, 1983 (48 FR 49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination with Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3207 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 Tribes or Tribal lands 
associated with this proposed regulation.

References Cited

    A complete list of references cited in this rulemaking is available 
on the internet at http://www.regulations.gov under Docket No. FWS-R4-
ES-2021-0036 and upon request from the Field Supervisor, Panama City 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authors

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

Signing Authority

    The Principal Deputy Director, Exercising the Delegated Authority 
of the Director, U.S. Fish and Wildlife Service, approved this document 
and authorized the undersigned to sign and submit the document to the 
Office of the Federal Register for publication electronically as an 
official document of the U.S. Fish and Wildlife Service. Martha 
Williams, Principal Deputy Director, U.S. Fish and Wildlife Service, 
approved this document on October 21, 2021, for publication.

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

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

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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


Sec.  17.11   [Amended]

0
2. Amend Sec.  17.11 in paragraph (h) by removing the entry for 
``Darter, Okaloosa (Etheostoma okaloosae)'' under ``Fishes'' from the 
List of Endangered and Threatened Wildlife.


Sec.  17.44   [Amended]

0
3. Amend Sec.  17.44 by removing and reserving paragraph (bb).

Krista Bibb,
Acting Chief, Branch of Policy and Regulations, U.S. Fish and Wildlife 
Service.
[FR Doc. 2021-25092 Filed 11-16-21; 8:45 am]
BILLING CODE 4333-15-P