[Federal Register Volume 88, Number 123 (Wednesday, June 28, 2023)]
[Rules and Regulations]
[Pages 41835-41854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-12982]
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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 234]
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: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are removing
the Okaloosa darter (Etheostoma okaloosae) from the Federal List of
Endangered and Threatened Wildlife (List) due to recovery. This final
rule is based on a thorough review of the best available scientific and
commercial information which indicates that the threats to the species
have been eliminated or reduced to the point that the species is no
longer in danger of extinction or likely to become in danger of
extinction within the foreseeable future. Therefore, the species no
longer meets the definition of a threatened species, and does not meet
the definition of an endangered species, under the Endangered Species
Act of 1973, as amended (Act). Accordingly, the prohibitions and
conservation measures provided by the Act will no longer apply to this
species.
DATES: This rule is effective July 28, 2023.
ADDRESSES: This final rule, supporting documents in preparing this
rule, the post-delisting monitoring plan, and the comments received on
the proposed rule are available for public inspection at https://www.regulations.gov under Docket No. FWS-R4-ES-2021-0036.
FOR FURTHER INFORMATION CONTACT: Lourdes Mena, Division Manager,
Florida 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. Individuals in the
United States who are deaf, deafblind, hard of hearing, or have a
speech disability may dial 711 (TTY, TDD, or TeleBraille) to access
telecommunications relay services. Individuals outside the United
States should use the relay services offered within their country to
make international calls to the point-of-contact in the United States.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Act, a species may be
removed from the Federal Lists of Endangered and Threatened Wildlife
and Plants (i.e., ``delisted'') if it is determined that the species
has recovered and no longer meets the definition of an endangered
species or a threatened species. Delisting a species can only be
completed by issuing a rule through the Administrative Procedure Act
rulemaking process (5 U.S.C. 551 et seq.).
What this document does. This rule removes the Okaloosa darter
(Etheostoma okaloosae) from the List of Endangered and Threatened
Wildlife 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
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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. We have determined that the Okaloosa darter should be delisted
because, based on an analysis of the five listing factors, it has
recovered and no longer meets the definition of an endangered species
or a threatened species.
Specifically, our recent review indicated that actions by the U.S.
Air Force and implementation of multiple conservation agreements with
local landowners have reduced erosion into streams to background
levels, restored and reconnected stream habitat, restored and improved
management of longleaf and watersheds, maintained historical water
flows, and improved and maintained water quality and riparian habitat
to the point that the Okaloosa darter no longer requires protections
under the Act. Accordingly, the species no longer meets the definition
of an endangered or a threatened species under the Act.
A species status assessment (SSA) report for the Okaloosa darter
was prepared by an SSA team (USFWS 2019, entire). 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.
Peer review and public comment. We evaluated the species' needs,
current conditions, and future conditions to inform our November 17,
2021, proposed rule (86 FR 64158). We sought the expert opinions of six
appropriate specialists regarding the species status assessment (SSA)
report, which informed the proposed rule. Out of the six reviews
requested, we received two responses. All comments were clarification-
based with some biological information submitted. All were readily
incorporated into the final version of the SSA report. The purpose of
peer review is to ensure our determination is based on scientifically
sound data, assumptions, and analyses. We invited these peer reviewers
to comment on the proposed rule and draft post-delisting monitoring
plan. We considered all comments and information we received during the
public comment period on the proposed delisting rule and the draft
post-delisting monitoring plan when developing this final rule.
Previous Federal Actions
On November 17, 2021, we published in the Federal Register (86 FR
64158) a proposed rule to delist the Okaloosa darter. Please refer to
that proposed rule for a detailed description of previous Federal
actions concerning this species. The proposed rule and supplemental
documents are provided at https://www.regulations.gov under Docket No.
FWS-R4-ES-2021-0036.
Summary of Comments and Changes From the Proposed Rule
In the proposed rule published on November 17, 2021 (86 FR 64158),
we requested that all interested parties submit written comments on the
proposal by January 18, 2022. We also contacted the Florida Fish and
Wildlife Commission (FWC), scientific experts and organizations, and
other interested parties and invited them to comment on the proposal. A
newspaper notice inviting the public to provide comments on the
proposed rule was published in the Northwest Florida Daily News and the
Tallahassee Democrat on November 19, 2021.
In preparing this final rule, we reviewed and fully considered the
two comments we received during the public period on the proposed rule
to delist the Okaloosa darter. We received one substantive comment from
the FWC that suggested increasing the frequency of surveys in the post-
delisting monitoring (PDM) plan from biannually to annually in years 1
through 4. After further discussion between the Service and FWC staff,
we collectively determined that biannual surveys would be adequate to
capture any future changes in Okaloosa darter population size, and thus
we made no changes to this final rule or the PDM plan based on this
comment. The other comment we received was not substantive. In summary,
we made no substantive changes to this final rule based on public
comments received. Minor, nonsubstantive changes and corrections have
been made throughout this final rule. In preparing this final rule, we
also refined the Status Throughout a Significant Portion of Its Range
analysis in order to better align with current policy and guidance.
Final Delisting Determination
Species Information
Below, we present a review of the taxonomy, life history, ecology,
and overall status of the Okaloosa darter, referencing data where
appropriate from the SSA report that was finalized for the species in
April 2019 (USFWS 2019, entire).
Background
The Okaloosa darter is a small (maximum size 49 millimeters (mm),
1.93 inches (in)) percid fish (perch family). 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 the
Okaloosa darter 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 2022c, p. 3-1; 76 FR
18087, 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). 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
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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 18087, 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 18087, 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 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).
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). Repeated rangewide surveys
in 2014 and 2020 indicated that overall abundance declined by about 24
percent from 2005 to 2014 and then a further 20 percent in 2020 (Jordan
and Jelks 2021, pp. 12). However, 2005 was an unusually good year for
the Okaloosa darter, and the 2014 and 2020 estimates likely reflect
some declines associated with dense canopy cover.
A thorough review of the taxonomy, life history, ecology, and
overall viability of the Okaloosa darter is presented in the SSA report
(USFWS 2019, entire; available at https://ecos.fws.gov/ecp/species/E00H/ and at https://www.regulations.gov under Docket No. FWS-R4-ES-
2021-0036).
Recovery
Section 4(f) of the Act (16 U.S.C. 1531 et seq.) directs us to
develop and implement recovery plans for the conservation and survival
of endangered and threatened species unless we determine that such a
plan will not promote the conservation of the species. Under section
4(f)(1)(B)(ii), recovery plans must, to the maximum extent practicable,
include objective, measurable criteria which, when met, would result in
a determination, in accordance with the provisions of section 4 of the
Act, that the species be removed from the List.
Recovery plans provide a roadmap for us and our partners on methods
of enhancing conservation and minimizing threats to listed species, as
well as measurable criteria against which to evaluate progress towards
recovery and assess the species' likely future condition. However, they
are not regulatory documents and do not substitute for the
determinations and promulgation of regulations required under section
4(a)(1) of the Act. A decision to delist a species is ultimately based
on an analysis of the best scientific and commercial data available and
consideration of the standards listed in 50 CFR 424.11(e) to determine
whether a species is no longer an endangered species or a threatened
species, regardless of whether that information differs from the
recovery plan.
There are many paths to accomplishing recovery of a species, and
recovery may be achieved without all of the criteria in a recovery plan
being fully met. For example, one or more criteria may be exceeded
while other criteria may not yet be accomplished. In that instance, we
may determine that the threats are minimized sufficiently, and that the
species is robust enough that it no longer meets the Act's definition
of an endangered species or a threatened species. In other cases, we
may discover new recovery opportunities after having finalized the
recovery plan. Parties seeking to conserve the species may use these
opportunities instead of methods identified in the recovery plan.
Likewise, we may learn new information about the species after we
finalize the recovery plan. The new information may change the extent
to which existing criteria are appropriate for identifying recovery of
the species. The recovery of a species is a dynamic process requiring
adaptive management that may, or may not, follow all 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 darter may
be initially downlisted (which occurred in 2011; see 76 FR 18087, April
1, 2011) and eventually delisted. Because 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 the Okaloosa darter
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 darter (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
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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, Florida,
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 the
Okaloosa darter under this criterion since 2011, when 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, more than 20 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 darter
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. Between 1995 and 2005, over 510 borrow pits
and non-point erosion sites (680 acres) have been rehabilitated and
maintained within Okaloosa darter watersheds (USAF 2022, p. 142) and
erosion rates are calculated to be nearly at background levels (USAF
2022, p. 143). This work was a major factor in the decision to
reclassify the species from Endangered to Threatened (USFWS 2011,
entire) and as such, this criterion should be considered fulfilled.
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. In fact, Eglin's longleaf pine/sandhill
management has been so effective, Eglin reached its recovery goal for
the Red-cockaded Woodpecker (RCW) in 2009 (USAF 2022, p. 134) with
continued population growth. Because the ranges of RCW and Okaloosa
darter overlap, continued management and protections associated with
RCW in the uplands will benefit Okaloosa darters. Additionally, Eglin
has committed to maintaining buffers around Okaloosa darter streams for
infrastructure and mission planning (Felix 2020, pers comm.). In
addition to protections and management associated with endangered
species, Eglin continues to monitor aquatic habitat quality through
macroinvertebrate and water quality monitoring (USAF 2022, p. 160).
Delisting Criterion 5: Natural, historical flow regimes are
maintained. Water withdrawals for human consumption in and around the
range of the Okaloosa darter are presently served by wells that tap the
Floridan Aquifer, which is declining in the most populated areas near
the coast (Pascale 1974, pp. 1-2). 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 drainages occupied by
the darter (USFWS 2017, p. 13). This criterion has been met.
Delisting Criterion 6: Water quality and riparian habitat have been
significantly improved and maintained. Water quality in Okaloosa darter
streams has been monitored consistently throughout the past 25 years.
At each monitoring site, standard water quality parameters are measured
and recorded and up to 20 sites per year are surveyed using the FDEP
rapid Biorecon and Stream Condition Index (SCI) methods (FDEP 2017). In
general, streams originating on Eglin exhibit pristine water quality
and high to very high scores on Biorecon and SCI surveys (Jordan and
Jelks 2022, p. 11; USFWS 2023, unpublished data). Streams under
anthropogenic pressure exhibit lower Okaloosa darter numbers or local
extirpations, however these anthropogenic pressures are limited to less
than 15 percent of the historic ranges and only 5 percent of the
currently occupied range (USFWS 2019, p. 15). Water Quality in Deer
Moss Creek and Shaw Still Branch continue to be negatively influenced
by treated sewage effluent applied to sprayfields adjacent to those
streams and 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 to 18 years (Landmeyer et al. 2022,
9(5):69), so we expect to observe water quality changes in upcoming
years. 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 the Okaloosa
darter in the Eglin AFB's integrated natural resources management plan
(INRMP), changes to which are reviewed and approved by both the Service
and by 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 (Hagedorn 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 darter or its 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 to 4 percent
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of the historical range (Ruckel Properties 2018, entire). In total, 90
to 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 darter has been conducted annually at 21
core sites distributed throughout the range since 1995. In 2005, 2014,
and 2020, 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 1990s through early 2000s, at which time declines
were observed at a subset of sites (Jordan and Jelks 2020, p. 11).
Multiple year-classes have been recorded in each of the six watersheds
in all years of study, regardless of declines (USFWS 2022, unpublished
data). 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, p. 10). Eglin AFB natural resource managers are
working to shift habitat management activities such as 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 darter was greater than 500,000 individuals in 2020 (Jordan
and Jelks 2021, p. 11) and rangewide densities generally remain above 2
darters per meter of inhabited stream (Jordan and Jelks 2021).
Maintaining multiple viable populations substantially reduces the risk
of species extinction, and future scenario modelling suggests that
resiliency and redundancy will remain sufficient to support the
viability of the species into the foreseeable future (USFWS 2019, pp.
70-72). 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, Swift, and Deer Moss
Creeks. 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, which 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 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 the Okaloosa darter. Eglin AFB is currently working with the
Service, 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, adds an upland buffer that 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, entire). 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 to 18 years (Landmeyer 2022, 9(5):69), so we expect to observe water
quality changes in upcoming years.
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 (USAF 2022d, appendix K) and by
developing enhanced BMPs to limit erosion during construction projects
and continuing to monitor 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 (33 U.S.C.
1251 et seq.). Eglin AFB 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 the Okaloosa darter occurs in multiple stream systems,
which provides redundancy, and no long-term threats are presently
impacting the Okaloosa darter at the species level within the
foreseeable future, this criterion has been met.
Regulatory and Analytical Framework
Regulatory Framework
Section 4 of the Act (16 U.S.C. 1533) and the implementing
regulations in title 50 of the Code of Federal Regulations set forth
the procedures for determining whether a species is an endangered
species or a threatened species, issuing protective regulations for
threatened species, and designating critical habitat for endangered
species. In 2019, jointly with the National Marine Fisheries Service,
the Service issued a final rule that revised the regulations in 50 CFR
424 regarding how we add, remove, and reclassify endangered and
threatened species and the criteria for designating listed species'
critical habitat (84 FR 45020; August 27, 2019). On the same day, the
Service also issued final regulations that, for species listed as
threatened species after September 26, 2019, eliminated the Service's
general protective regulations automatically applying to threatened
species the prohibitions that section 9 of the Act applies to
endangered species (84 FR 44753; August 27, 2019).
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
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species or a threatened species because of any of the following
factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects. The determination to delist a
species must be based on an analysis of the same five factors.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we must evaluate all
identified threats by considering the species' expected response and
the effects of the threats--in light of those actions and conditions
that will ameliorate the threats--on an individual, population, and
species level. We evaluate each threat and its expected effects on the
species, then analyze the cumulative effect of all of the threats on
the species as a whole. We also consider the cumulative effect of the
threats in light of those actions and conditions that will have
positive effects on the species--such as any existing regulatory
mechanisms or conservation efforts. The Secretary determines whether
the species meets the definition of an ``endangered species'' or a
``threatened species'' only after conducting this cumulative analysis
and describing the expected effect on the species now and in the
foreseeable future.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' 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 we 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 the foreseeable
future as a particular number of years. Analysis of the foreseeable
future uses the best scientific and commercial data available and
should consider the timeframes applicable to the relevant threats and
to the species' likely responses to those threats in view of its life-
history characteristics. Data that are typically relevant to assessing
the species' biological response include species-specific factors such
as lifespan, reproductive rates or productivity, certain behaviors, and
other demographic factors.
Analytical Framework
The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
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 discussion, we summarize the key conclusions from the SSA
report; the full SSA report can be found on the Service website at
https://ecos.fws.gov/ecp/species/E00H/ and at https://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 the Okaloosa darter, as development leads, through multiple
pathways, to pollution, erosion, and sedimentation; altered water
flows; and dispersal barriers. Land use and management practices such
as road building, timber harvesting, and fire suppression can affect
abundance of Okaloosa darters on Eglin AFB. The effects of a changing
climate, such as increasing stream temperatures, could become a threat
to the Okaloosa darter throughout its geographic range in the future;
however,
[[Page 41841]]
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
the 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, and road or development projects (e.g.,
solar power grids); sedimentation 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 500,000 darters across its range.
Management for the Okaloosa darter 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 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 18087, April 1, 2011, p. 18090). 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 to 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 per year in
Okaloosa darter watersheds in 1994 to approximately 2,500 tons per year
in 2010 (Pizzolato 2018, 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 such as 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 darter into new areas
within drainages (USFWS 2011, 76 FR 18087, April 1, 2011, p. 18090).
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 2022, 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 (Picoides borealis) 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, and 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 BMPs (USAF 2022, 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 the Okaloosa darter and
its 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 the 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). We completed
consultation on this project under section 7(a)(2) of the Act. 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 darters
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 the Okaloosa
darter, to date the Mid-Bay
[[Page 41842]]
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. The existing corridor could be widened to four lanes if
future traffic projections justify the need. The corridor has already
been cleared and grassed, so no additional sedimentation or erosion-
related impacts are anticipated should an expansion to four lanes
occur. Any future road projects will require consultation under section
7(a)(2) of the Act (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's 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 identified in any
environmental impact analysis for such transactions (Felix 2018, pers.
comm.).
In 2012, the Service issued a biological opinion to the Federal
Highway Administration (FHWA) for widening SR 123 from a two-lane
undivided roadway to a four-lane divided roadway from SR 85 South to SR
85 North (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 displacement, injury, and mortality to Okaloosa darters
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 darters: 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, and implementation of the plan 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, to help ensure the species' conservation
when the Act's protections are removed. The BMPs and any additional
requirements will be finalized before any projects move forward; to
date, no such projects have been undertaken.
Stormwater Control
Development and construction activity in residential areas outside
of Eglin AFB and primarily in the downstream-most portion of the
Okaloosa darter's 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
2022b, 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, 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 meters in the
headwaters just above the sprayfield down to 1 or fewer Okaloosa darter
per 20 meters in the remaining 4 kilometers or so of stream downstream
from the sprayfield (Jordan 2017, pp. 5-7; Jordan 2018, 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 the 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
[[Page 41843]]
darters (Hitt et al. 2016, entire; Fuzzen et al. 2016, entire).
Water Withdrawals
Water withdrawals for human consumption in and around the range of
the Okaloosa darter are presently served by wells that tap the Floridan
Aquifer, which is declining in the most populated areas near the coast
(Pascale 1974, pp. 1-2). 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 drainages occupied by
the darter (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 kilometers 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's 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 the Okaloosa darter is
lacking; however, declines in abundance following the impoundment 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 the Okaloosa
darter is limited, and individuals cannot expand northward, stream
temperature increases or sea level rise that would cause stream
inundation could pose a threat to the 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's 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
historical saltwater isolation (Austin et al. 2011, p. 987).
Impoundments
Many streams within the range of the Okaloosa darter 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 darters 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. 3-4;
Reeves et al. 2016, p. 1376). Okaloosa darters living downstream of
impoundments are also negatively affected, sometimes for a considerable
distance. For instance, the roughly 3 kilometers (60 percent) of Swift
Creek below College Pond and roughly 2 kilometers (100 percent) of
Foxhead Branch below Brandt Pond currently lack Okaloosa darters
(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 darters
and plans to continue this work indefinitely (USAF 2022, pp. 5-12).
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
the Okaloosa darter was 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 upcoming funding cycles (USAF 2022d, appendix
K). Additionally, 13 impoundments still exist, 4 of which are caused by
beaver activity. Beavers that remain are primarily in the headwater
reaches where the Okaloosa darter is either not present or would be in
very low density. Nuisance beavers are managed under a cooperative
agreement with the U.S. Department of Agriculture. USFWS is currently
working with Eglin and other partners to secure funding for the
restoration of Swift Creek via removal of College Pond (Tate 2020,
pers. comm.). 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
[[Page 41844]]
canopy may reduce densities of the Okaloosa darter. 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
negative 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, if needed, 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 the Okaloosa darter 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 the Okaloosa darter. The brown darter is native to
Okaloosa darter watersheds (Austin 2011, unpublished data) and is not
altering the distribution or abundance of the Okaloosa darter where
they coexist (USFWS 2019, p. 23). Flathead catfish (Pylodictis
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 the Okaloosa darter. 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 (USAF 2022d, appendix K). Early detection and
targeted management of invasive species will minimize or eliminate this
threat to the Okaloosa darter in the future (Tate 2019, pers. comm.).
Summary of Factors Influencing Viability
The vast majority of the range of the Okaloosa darter is located on
Eglin AFB, where many conservation and restoration actions have been
successful in restoring the Okaloosa darter to regions from which it
had previously been extirpated and increasing darter densities since
the time of its listing in 1973. Much progress has been made in
implementing conservation actions since the Okaloosa darter was
downlisted to threatened in 2011. 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
2022, 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, as well as changes to water flow from
impoundments that can result from urbanization, can lead to a decrease
in Okaloosa darter numbers. 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 (Pizzolato 2018, pers. comm.). Accordingly, darter numbers
increased in the Boggy Bayou drainages earlier than in the Rocky Bayou
drainages (Jordan and Jelks 2021, p. 9). Okaloosa darters have also
been shown to quickly recolonize restored streams (Reeves et al. 2016,
entire) and reclaim 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 the Okaloosa darter 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
the 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).
[[Page 41845]]
For analysis purposes, we delineated resiliency units for the
Okaloosa darter 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 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 darters
that are isolated from other Okaloosa darters 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 the 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 (USFWS
2019, p. 33).
We assess current resiliency for the Okaloosa darter 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 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 the
Okaloosa darter is approximately 500,000 (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 Creeks) together total only 4
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 the Okaloosa Darter Based on Estimated Population Size, Population Trends, and Vulnerability
--------------------------------------------------------------------------------------------------------------------------------------------------------
Population trend
Population Estimated slope (avg. count/ Population trend Resiliency Population
population year) vulnerability (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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)
--------------------------------------------------------------------------------------------------------------------------------------------------------
We classified resiliency by species' presence, density, and
population sizes. Population sizes of fewer than 10,000 Okaloosa
darters are considered ``low,'' 10,000 to 50,000 are ``moderate,'' and
more than 50,000 are ``high'' resiliency. 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 the Okaloosa darter as the total number of populations
and the resiliency of population segments and their distribution within
and among representative units. Also, there are
[[Page 41846]]
multiple populations in two of the stream systems.
Six populations comprise the vast majority of the historical range
of the Okaloosa darter 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), the Okaloosa darter has
sufficient genetic variability. Representation is demonstrated through
the genetic structure of the populations.
Future Condition
The biggest potential threat to the 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 the Okaloosa darter. For instance,
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 the effects to the Okaloosa darter, 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 the Okaloosa darter, 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; we 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, and 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 (USFWS 2019, entire) for further
description of the methodologies we
[[Page 41847]]
used to model these scenarios and their impacts to the 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 the current
estimates. 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 (scenario 1b) 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, unless
restoration occurs. Swift Creek would lose almost 60 percent of its
population unless habitat restoration occurs, but if restoration occurs
(scenario 1b), 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, 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 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 in meters (m) 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.
[[Page 41848]]
As expected, short-term estimates increased for all populations, with
the highest relative increases in fragmented populations (Swift and
Toms Creeks) or those impaired by urbanization (Deer Moss and Mill
Creeks). 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 Creeks
than in Rocky and Turkey Creeks. In the long term, all populations
except Turkey and Rocky Creeks still see an increase from current
conditions, though not quite as large. Turkey and Rocky Creeks 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 Creeks 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 in meters (m) 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
----------------------------------------------------------------------------------------------------------------
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 1.0 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
[[Page 41849]]
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 the ``status quo''
scenario, 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 in meters (m) 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
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 2.0 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 1.0 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 Creeks
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 of 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 Creeks' populations would maintain high
resiliency, above 300,000 individuals, even in the long term.
[[Page 41850]]
Table 5--Scenario 4 of Worst Management for Okaloosa Darter Recovery
[Total stream lengths in meters (m) 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
----------------------------------------------------------------------------------------------------------------
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 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 darter exhibits
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). The Okaloosa darter has 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).
[[Page 41851]]
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
darter; 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, 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 the Okaloosa darter's 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 experiences 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
maintain resiliency. The Toms Creek population, being the only
population in its representative unit, will see decreased resiliency in
the short term in two (``poor'' and ``worst'') of the scenarios, and in
the long term in three scenarios (all except ``ideal restoration, good
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 Act's 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, above.
Status Throughout All of Its Range
The Okaloosa darter is a narrow endemic, occurring in six stream
systems in Walton and Okaloosa Counties, Florida. Okaloosa darters
currently occur within all 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 more than 500,000
darters across the species' range. 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
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. The
Okaloosa darter occurs in multiple stream systems, which provides
redundancy, and no long-term threats are presently impacting the
Okaloosa darter at the species level. Accordingly, we conclude that the
species is not currently in danger of extinction, and thus does not
meet the Act's definition of an endangered species, throughout its
range.
In considering whether the species continues to meet the Act's
definition of a threatened species (likely to become an endangered
species within the foreseeable future) throughout its range, we
identified the foreseeable future for the Okaloosa darter to be 20 to
50 years based on our ability to reliably determine that the threats
are likely and 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 the
Okaloosa darter 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 throughout all of its range in the
foreseeable future, we proceed to evaluating 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
[[Page 41852]]
to become so in the foreseeable future in that portion. Depending on
the case, it might be more efficient for us to address the
``significance'' question or the ``status'' question first. We can
choose to address either question first. Regardless of which question
we address first, if we reach a negative answer with respect to the
first question that we address, we do not need to evaluate the other
question for that portion of the species' range.
In undertaking this analysis for the Okaloosa darter, 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: urbanization, land use and management
practices on Eglin AFB, and sea level rise around the southern reaches
of watersheds.
Urbanization is the greatest threat to the Okaloosa darter, as
development leads, through multiple pathways, to pollution, erosion,
sedimentation, altered water flows, and dispersal barriers. However,
because over 90 percent of the range of the Okaloosa darter will
continue to be managed under the Eglin AFB INRMP, we expect management
to improve overall conditions for the species across its range. Because
populations of the Okaloosa darter within Eglin AFB will continue to
benefit from the conservation protections, where urbanization is not
considered to be a current or future threat, our analysis focuses on
southern portions of watersheds outside of Eglin AFB as a portion of
the range that may have a different status. This portion overlaps with
three populations of Okaloosa darter: Swift, Deer Moss, and Mill
Creeks. Of these, Swift Creek rangewide currently has moderate
resiliency with increasing population size now and into the future in
all scenarios. Both Deer Moss and Mill Creeks rangewide are considered
to have low resiliency with decreasing population size now, with the
potential for extirpation in the future without proper management.
Because of the current and projected future status of the Deer Moss and
Mill Creeks populations, and because sea level rise will only affect
the populations of Okaloosa darter within this portion, our analysis
indicates that the status of this portion of the range (i.e., southern
portions of watersheds outside of Eglin AFB) may be different than the
overall range.
We then proceeded to consider whether this portion of the range
(Deer Moss and Mill Creeks) is significant. The Service's most recent
definition of ``significant'' within agency policy guidance has been
invalidated by court order (see Desert Survivors v. U.S. Department of
the Interior, 321 F. Supp. 3d 1011, 1070-74 (N.D. Cal. 2018)). In
undertaking this analysis for the Okaloosa darter, we considered
whether the Deer Moss and Mill Creeks portion of the species' range may
be significant based on its biological importance to the overall
viability of the Okaloosa darter. Therefore, for the purposes of this
analysis, when considering whether this portion is significant, we
considered whether the portion may (1) occur in a unique habitat or
ecoregion for the species; (2) contain high-quality or high-value
habitat relative to the remaining portions of the range, for the
species' continued viability in light of the existing threats; (3)
contain habitat that is essential to a specific life-history function
for the species and that is not found in the other portions (for
example, the principal breeding ground for the species); or (4) contain
a large geographic portion of the suitable habitat relative to the
remaining portions of the range for the species.
This portion (Deer Moss and Mill Creeks' populations) represents a
small portion (approximately 2 and 1 percent, respectively) of the
Okaloosa darter's range. Although these populations contribute to the
rangewide representation and redundancy of the darter, this portion
does not constitute a large geographic area relative to the range as a
whole. Additionally, this portion does not contribute high-quality
habitat or constitute high-value habitat (e.g., refugia) for the
Okaloosa darter. In addition, this portion does not constitute an area
of habitat that is essential to a specific life-history function for
the species that is not found in the remainder of the range.
Overall, we found no substantial information that would indicate
this portion of the Okaloosa darter's range is significant in terms of
the above habitat considerations. As a result, we determined that this
portion does not represent a significant portion of the Okaloosa
darter's range. Therefore, we conclude that the species is not in
danger of extinction now or likely to become so in any significant
portion of its range in the foreseeable future. This finding does not
conflict with the courts' holdings in Desert Survivors v. U.S.
Department of the Interior, 321 F. Supp. 3d 1011, 1070-74 (N.D. Cal.
2018) and Center for Biological Diversity v. Jewell, 248 F. Supp. 3d
946, 959 (D. Ariz. 2017) because, in reaching these conclusions, we did
not need to consider whether any portions are significant and therefore
did not apply the definition of ``significant'' in the Final Policy on
Interpretation of the Phrase ``Significant Portion of its Range'' in
the Endangered Species Act's Definitions of ``Endangered Species'' and
``Threatened Species'' (79 FR 37578; July 1, 2014) that those court
decisions held was invalid.
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 are
delisting (removing) the Okaloosa darter from the Federal List of
Endangered and Threatened Wildlife.
Effects of This Rule
This final rule will revise 50 CFR 17.11(h) and 17.44(bb) by
removing the 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 provided by the Act
will no longer apply to this species. Federal agencies will no longer
be required to consult with the Service under section 7 of the Act in
the event that activities they authorize, fund, or carry out may affect
the Okaloosa darter. However, approximately 90 percent of the 457-
square-kilometer (176-square-mile) watershed drainage area that
historically supported the Okaloosa darter is Federal property under
the management of Eglin AFB, and about 98.7 percent of the stream
length in the current range of the Okaloosa darter is within the
boundaries of Eglin AFB.
As discussed above, Eglin AFB encompasses the headwaters of all six
of these drainages. Benefits from 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
2022c, p. 3-1). Thus, the INRMP will continue to provide for the
conservation of the Okaloosa darter 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 the habitat
and resources required by the Okaloosa darter into the future. There is
no critical habitat designated for this
[[Page 41853]]
species, so this rule has no effect on 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
ensure that the species' status does not deteriorate, and that if a
decline is detected, measures are taken to halt the decline so as to
avoid the need for us to propose listing of the species again. If at
any time during the monitoring period data indicate that protective
status under the Act should be reinstated, we can initiate listing
procedures, including, if appropriate, emergency listing.
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 implement an effective PDM plan for the Okaloosa darter.
The PDM plan was developed based 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 is a
fundamental goal for the PDM plan. The PDM plan has identified
measurable management thresholds and responses for detecting and
reacting to significant changes in Okaloosa darter's numbers,
distribution, and persistence. If declines are detected equaling or
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 or additional protection under the Act.
We are delisting the Okaloosa darter based on all six extant
populations exhibiting genetic differentiation and the species being
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 is, in part, due to conservation
actions taken by stakeholders, we have developed a PDM plan for the
Okaloosa darter. The PDM plan discusses the current status of the taxon
and describes the methods that will be implemented for monitoring
following delisting. The PDM plan: (1) Summarizes the status of the
Okaloosa darter at the time of delisting; (2) describes frequency and
duration of monitoring; (3) discusses monitoring methods and sampling
regimes; (4) defines what potential triggers will be evaluated to
address the need for additional monitoring; (5) outlines reporting
requirements and procedures; (6) defines 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 the
Okaloosa darter.
The Service prepared this 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 the 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 will monitor the
status of the Okaloosa darter using a structured sampling regime over a
10-year period.
The final PDM plan for the Okaloosa darter can be accessed at
https://www.regulations.gov under Docket No. FWS-R4-ES-2021-0036, and
through the Service's Environmental Conservation Online System at
https://ecos.fws.gov/ecp/species/E00H.
Required Determinations
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. 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
Secretary's 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
affected by this final rule.
References Cited
A complete list of references cited in this rulemaking is available
on the internet at https://www.regulations.gov under Docket No. FWS-R4-
ES-2021-0036 and upon request from the Field Supervisor, Florida
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Authors
The primary authors of this rule are staff members of the Fish and
Wildlife Service's Species Assessment Team and the Florida Ecological
Services Field Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Plants,
Reporting and recordkeeping requirements, Transportation, Wildlife.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as set forth below:
[[Page 41854]]
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.
Sec. 17.11 [Amended]
0
2. In Sec. 17.11, amend paragraph (h) by removing the entry for
``Darter, Okaloosa'' 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).
Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2023-12982 Filed 6-27-23; 8:45 am]
BILLING CODE 4333-15-P