Federal Register, Volume 88 Issue 81 (Thursday, April 27, 2023) 2023 Federal Register, 88 FR 25512-25542; Centralized Library: U.S. Fish and Wildlife Service -

[Federal Register Volume 88, Number 81 (Thursday, April 27, 2023)]
[Unknown Section]
[Pages 25512-25542]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08849]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R3-ES-2019-0020; FF09E21000 FXES1111090FEDR 234]
RIN 1018-BD98

Endangered and Threatened Wildlife and Plants; Threatened Species
Status With Section 4(d) Rule for Big Creek Crayfish and St. Francis
River Crayfish and Designation of Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
threatened species status under the Endangered Species Act of 1973
(Act), as amended, for the Big Creek crayfish (Faxonius peruncus) and
the St. Francis River crayfish (Faxonius quadruncus), two crayfish
species from southern Missouri. We also finalize a rule under the
authority of section 4(d) of the Act that provides regulatory measures
that are necessary and advisable to provide for the conservation of
these species. In addition, we designate critical habitat for the
species; in total, approximately 1,069 river miles (1,720 river

[[Page 25513]]

kilometers) for the Big Creek crayfish and 1,043 river miles (1,679
river kilometers) for the St. Francis River crayfish in Iron, Madison,
St. Francois, Washington, and Wayne Counties, Missouri, fall within the
boundaries of the critical habitat designations. This rule applies the
protections of the Act to these species and their designated critical
habitats.

DATES: This rule is effective May 30, 2023.

ADDRESSES: This final rule is available on the internet at https://www.regulations.gov and https://www.fws.gov/midwest/. Comments and
materials we received, as well as supporting documentation we used in
preparing this rule, are available for public inspection at https://www.regulations.gov at Docket No. FWS-R3-ES-2019-0020.
The coordinates or plot points or both from which the maps are
generated are included in the decision file for the critical habitat
designations and are available at https://www.regulations.gov at Docket
No. FWS-R3-ES-2019-0020, and at the field office responsible for the
designations (see FOR FURTHER INFORMATION CONTACT, below). Any
additional tools or supporting information that we developed for the
critical habitat designations will also be available at the Service's
website and at https://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: John Weber, Field Supervisor; U.S.
Fish and Wildlife Service; Missouri Ecological Services Field Office;
101 Park DeVille Drive, Suite A; Columbia, MO 65203-0057; telephone
573-234-2132. Individuals in the United States who are deaf, deafblind,
hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or
TeleBraille) to access telecommunications relay services. Individuals
outside the United States should use the relay services offered within
their country to make international calls to the point-of-contact in
the United States.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule. Under the Act, a species warrants
listing if it meets the definition of an endangered species (in danger
of extinction throughout all or a significant portion of its range) or
a threatened species (likely to become endangered within the
foreseeable future throughout all or a significant portion of its
range). If we determine that a species warrants listing, we must list
the species promptly and designate the species' critical habitat to the
maximum extent prudent and determinable. We have determined that the
Big Creek crayfish and the St. Francis River crayfish both meet the
definition of threatened species; therefore, we are listing them as
such and finalizing designations of critical habitat for both species.
Both listing a species as an endangered or threatened species and
designating critical habitat can be completed only by issuing a rule
through the Administrative Procedure Act rulemaking process.
What this document does. This rule lists the Big Creek crayfish
(Faxonius peruncus) and the St. Francis River crayfish (Faxonius
quadruncus) as threatened species and designates critical habitat for
both species. We are designating approximately 1,069 river miles (1,720
river kilometers) for the Big Creek crayfish and 1,043 river miles
(1,679 river kilometers) for the St. Francis River crayfish in Iron,
Madison, St. Francois, Washington, and Wayne Counties, Missouri. We are
also finalizing a rule under the authority of section 4(d) of the Act
that provides measures that are necessary and advisable to provide for
the conservation of these species.
The basis for our action. Under the Act, we may determine that a
species is an endangered or threatened species based on any of five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. We have determined that displacement (Factor E) by
the woodland crayfish (Faxonius hylas) is the primary threat to both
the Big Creek crayfish and the St. Francis River crayfish. However,
degraded water quality (Factor A) from heavy metal mining activities in
the watershed is impacting the species and may act synergistically with
the spread of the nonnative woodland crayfish and subsequent
displacement of the Big Creek crayfish and St. Francis River crayfish.
The existing regulatory mechanisms are not adequately addressing these
threats such that the species do not warrant listing (Factor D).
Section 4(a)(3) of the Act requires the Secretary of the Interior
(Secretary) to designate critical habitat concurrent with listing to
the maximum extent prudent and determinable. Section 3(5)(A) of the Act
defines critical habitat as (i) the specific areas within the
geographical area occupied by the species, at the time it is listed, on
which are found those physical or biological features (I) essential to
the conservation of the species and (II) which may require special
management considerations or protections; and (ii) specific areas
outside the geographical area occupied by the species at the time it is
listed, upon a determination by the Secretary that such areas are
essential for the conservation of the species. Section 4(b)(2) of the
Act states that the Secretary must make the designation on the basis of
the best scientific data available and after taking into consideration
the economic impact, the impact on national security, and any other
relevant impacts of specifying any particular area as critical habitat.

Previous Federal Actions

On September 17, 2020, we published in the Federal Register (85 FR
58192) a proposed rule to list the Big Creek crayfish and the St.
Francis River crayfish as threatened species under the Act, to adopt a
species-specific rule issued under section 4(d) of the Act (``4(d)
rule'') that provides for the protection of the Big Creek crayfish and
the St. Francis River crayfish, and to designate critical habitat for
both species under the Act. Please refer to that proposed rule for a
detailed description of previous Federal actions concerning this
species.
During the public comment period for the September 17, 2020,
proposed rule, we received a request for a public hearing. On April 27,
2021, we published a document (86 FR 22127) reopening the September 17,
2020, proposed rule's comment period for an additional 30 days and
announcing a public informational meeting and public hearing on the
proposed rule. We held the virtual public informational meeting
followed by a public hearing on May 13, 2021.

Summary of Changes From the Proposed Rule

The final rule incorporates changes to our September 17, 2020,
proposed rule (85 FR 58192) and our species status assessment report
based on the comments we received, as discussed below under Summary of
Comments and Recommendations. We have also revised our significant
portion of the range analysis.
Based on information we received in comments and our further
consideration, in this rule, we refine the 4(d) rule for these species
to more clearly define take prohibitions and to accurately regulate
only those activities that are necessary and advisable for the
protection of the Big Creek crayfish and the St. Francis River crayfish
(see

[[Page 25514]]

Provisions of the 4(d) Rule, below). The Missouri Department of
Conservation (MDC) informed us that adopting two of the exceptions to
the prohibitions in the proposed 4(d) rule (the exceptions to the
incidental take prohibitions for a person capturing crayfish for
educational and observation purposes, and for a person capturing and
possessing up to 25 of each species for use as bait) would conflict
with the Wildlife Code of Missouri (Missouri Code). Under the Missouri
Code, any species added to the Federal List of Endangered and
Threatened Wildlife is also added to Missouri's State list of
endangered species. Because the Missouri Code also prohibits the
purposeful take of any species listed by the State as endangered,
allowing capture of the crayfishes for educational and observation
purposes and for use as bait would be in direct conflict with the
Missouri Code and hinder the MDC's ability to conserve the species. The
MDC also expressed concerns that these two exceptions would hinder the
enforcement of the prohibition on activities that may facilitate the
introduction or spread of the invasive woodland crayfish. After
reviewing the MDC's comment and further coordinating with the State of
Missouri, we conclude that adopting those two exceptions to the
prohibitions in the 4(d) rule would undermine the State's ability to
provide conservation for the species, and we do not include them in
this final rule.
In this rule, we also expand the exception to the prohibitions in
the proposed 4(d) rule concerning incidental take caused by restoration
activities or other activities that will result in an overall benefit
to one or both of the species. In this exception, we now include the
additional restoration activity of replacing in-stream low water
crossings that obstruct movement of aquatic organisms with crossings
that facilitate the movement of species and materials. Replacing these
crossings is expected to result in an overall benefit to one or both
species and including it as an exception is an additional activity that
we would expect to be beneficial to the conservation of the species. We
removed mention of specific Federal agencies that we may consult with
on these activities. We removed the list of Federal agencies to reduce
confusion, as we would consult whenever a Federal nexus exists, not
only with the Federal agencies we specifically named in the proposed
4(d) rule. We also added ``surface and groundwater withdrawals'' to the
list of prohibited activities that could impact the hydrological flows
such that the species' reproduction or survival will be impacted, in an
effort to provide a more detailed list of such activities.
Lastly, in this critical habitat designation, we do not include
``[s]paces under rocks or shallow burrows in gravel that provide
refugia'' as a physical or biological feature. That physical and
biological feature, which was included in the proposed designation, is
redundant with the following physical or biological feature that
remains in this designation: ``Adequately low stream embeddedness so
that spaces under rocks and cavities in gravel remain available to the
Big Creek crayfish and St. Francis River crayfish.''

Supporting Documents

A species status assessment (SSA) team prepared an SSA report for
the Big Creek crayfish and the St. Francis River crayfish. The SSA team
was composed of Service biologists, in consultation with other species
experts. The SSA report represents a compilation of the best scientific
and commercial data available concerning the status of the species,
including the impacts of past, present, and future factors (both
negative and beneficial) affecting the species.
In accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), and our August 22,
2016, memorandum updating and clarifying the role of peer review of
listing actions under the Act, we solicited independent scientific
review of the information contained in the SSA report. We sent the SSA
report to four independent peer reviewers and received one response.
The peer reviews can be found at https://www.regulations.gov. In
preparing the proposed rule, we incorporated the results of these
reviews, as appropriate, into the SSA report, which was the foundation
for the proposed rule and this final rule.

I. Final Listing Determination

Background

A thorough review of the taxonomy, life history, and ecology of the
Big Creek crayfish and the St. Francis River crayfish is presented in
the SSA report (Service 2022, entire).
The Big Creek crayfish (Faxonius peruncus) is a small, olive-tan
crayfish with blackish blotches and specks over the upper surface of
pincers, carapace, and abdomen. Length of adult individuals ranges from
1.1 to 2.2 inches (in) (2.8 to 5.6 centimeters (cm)). The St. Francis
River crayfish (Faxonius quadruncus) is a small, dark brown crayfish
with blackish blotches or specks over the upper surfaces of the
pincers, carapace, and abdomen. Lengths of adult individuals of St.
Francis River crayfish have been observed to be similar to adult Big
Creek crayfish.
Both the Big Creek crayfish and the St. Francis River crayfish have
localized distributions in the Upper St. Francis River watershed
upstream of Wappapello Dam in Iron, Madison, St. Francois, Washington,
and Wayne Counties in southeastern Missouri (see figure 1, below). The
Big Creek crayfish appears most abundant in Big Creek and other streams
on the west side of the watershed, as well as in the Twelvemile Creek
subwatersheds on the east side; the St. Francis River crayfish mainly
inhabits the upper St. Francis River tributaries on the upper end of
the Upper St. Francis River watershed. Despite occupying the Upper St.
Francis River watershed at a coarse spatial scale, these two species
have been observed at the same location only seven times and exhibit
mostly discrete distributions (Westhoff 2011, pp. 34-36).
Big Creek crayfish are generally found in streams with widths less
than 33 feet (ft) (10 meters (m)) under small rocks or in shallow
burrows in headwater streams and small rocky creeks in shallow depths.
St. Francis River crayfish are generally found in swiftly moving
streams under rocks and boulders in small headwater streams and up to
moderately larger rivers. St. Francis River crayfish may prefer pool/
backwater areas and run macrohabitats over faster riffles.
Given that both the Big Creek crayfish and St. Francis River
crayfish are habitat generalists (Westhoff 2017, pers. comm.) and not
all reaches of streams within the watershed have been sampled, it is
likely that the species occur at more locations in the watershed.
Therefore, we defined the species' ranges as the streams within
subwatersheds (12-digit hydrologic units) known to be occupied by each
species. We consider these ranges to be a more accurate depiction of
the actual ranges of the Big Creek crayfish and St. Francis River
crayfish than using only known locations. Within the St. Francis River
mainstem (where it is a 5th order stream), the Big Creek crayfish also
intermittently occurs in 86 river miles (rmi) (139 river kilometers
(km)), and the St. Francis River crayfish occurs in 99 rmi (159 km).
Thus, the Big Creek crayfish is found in 1,069 rmi (1,720 km) and the
St. Francis River Crayfish is found in 1,043 rmi (1,679 km) in the
Upper St. Francis watershed.

[[Page 25515]]

Individuals of the Big Creek crayfish and St. Francis River
crayfish mate in the fall. Big Creek crayfish females generate an
average of 61 eggs, and St. Francis River crayfish females generate an
average of 43 to 81 eggs (Pflieger 1996, pp. 116, 122). The normal
lifespan for both the Big Creek crayfish and the St. Francis River
crayfish appears to be about 2 years (Pflieger 1996, pp. 116, 122). We
presume that both species' feeding habits are similar to those of other
crayfish species in the region, and their diets likely consist of plant
detritus, periphyton, and invertebrates.
Based on genetic analyses (Fetzner and DiStefano 2008, pp. 12-15),
we consider the Big Creek crayfish species to consist of two
populations (referred to as the Main and Twelvemile Creek populations),
whereas the St. Francis River crayfish species consists of a single
population (see figure 1, below). We have no evidence to indicate that
there has been a reduction in the number of populations for either
species from historical conditions. For analytical purposes and for
better representation of groups of individuals that occupy the same
area and are subject to the same environmental pressures, we defined
finer-scale subpopulations. We consider a subpopulation to be those
individuals that are able to interbreed and occur within the same
stream reach of occupied habitat. Therefore, multiple subpopulations
make up the single population (and species) of the St. Francis River
crayfish, and multiple subpopulations make up the two populations of
the Big Creek crayfish. For Big Creek crayfish and St. Francis River
crayfish subpopulations to be healthy, they require a population size
and growth rate sufficient to withstand natural environmental
fluctuations and habitat of sufficient quantity and quality to support
all life stages (specific details of each of these requirements remains
unclear). Healthy subpopulations of each species also require gene flow
among subpopulations and a native community structure free from
nonnative crayfish species that may outcompete and ultimately displace
the two species (for more information, see chapter 2 of the SSA
report).
[GRAPHIC] [TIFF OMITTED] TR27AP23.150

Figure 1. Range of the Big Creek crayfish (left) and St. Francis River
crayfish (right) in Missouri.

Regulatory and Analytical Framework

Regulatory Framework

Section 4 of the Act (16 U.S.C. 1533) and the implementing
regulations in title 50 of the Code of Federal Regulations set forth
the procedures for determining whether a species is an endangered
species or a threatened species, issuing protective regulations for
threatened species, and designating critical habitat for endangered and
threatened species. In 2019, jointly with the National Marine Fisheries
Service, the Service issued a final rule that revised the regulations
in 50 CFR part 424 regarding how we add, remove, and reclassify
endangered and threatened species and the criteria for designating
listed species' critical habitat (84 FR 45020; August 27, 2019). On the
same day, the Service also issued final regulations that, for species
listed as threatened species after September 26, 2019, eliminated the
Service's general protective regulations automatically applying to
threatened species the prohibitions that section 9 of the Act applies
to endangered species (84 FR 44753; August 27, 2019).
The Act defines an ``endangered species'' as a species that is in
danger of extinction throughout all or a significant portion of its
range, and a ``threatened species'' as a species that is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range. The Act requires that we
determine whether any species is an endangered species or a threatened
species because of any of the following factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;

[[Page 25516]]

(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we evaluate all identified
threats by considering the expected response by the species and the
effects of the threats--in light of those actions and conditions that
will ameliorate the threats--on an individual, population, and species
level. We evaluate each threat and its expected effects on the species,
then analyze the cumulative effect of all of the threats on the species
as a whole. We also consider the cumulative effect of the threats in
light of those actions and conditions that will have positive effects
on the species, such as any existing regulatory mechanisms or
conservation efforts. The Secretary determines whether the species
meets the definition of an ``endangered species'' or a ``threatened
species'' only after conducting this cumulative analysis and describing
the expected effect on the species now and in the foreseeable future.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' Our
implementing regulations at 50 CFR 424.11(d) set forth a framework for
evaluating the foreseeable future on a case-by-case basis. The term
``foreseeable future'' extends only so far into the future as the
Services can reasonably determine that both the future threats and the
species' responses to those threats are likely. In other words, the
foreseeable future is the period of time in which we can make reliable
predictions. ``Reliable'' does not mean ``certain''; it means
sufficient to provide a reasonable degree of confidence in the
prediction. Thus, a prediction is reliable if it is reasonable to
depend on it when making decisions. It is not always possible or
necessary to define foreseeable future as a particular number of years.
Analysis of the foreseeable future uses the best scientific and
commercial data available and should consider the timeframes applicable
to the relevant threats and to the species' likely responses to those
threats in view of its life-history characteristics. Data that are
typically relevant to assessing the species' biological response
include species-specific factors such as lifespan, reproductive rates
or productivity, certain behaviors, and other demographic factors.

Analytical Framework

The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
threats to the species. The SSA report does not represent our decision
on whether the species should be listed as an endangered or threatened
species under the Act. 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.
To assess the viability of the Big Creek crayfish and the St.
Francis River crayfish, we used the three conservation biology
principles of resiliency, redundancy, and representation (Shaffer and
Stein 2000, pp. 306-310). Briefly, resiliency supports the ability of
the species to withstand environmental and demographic stochasticity
(for example, wet or dry, warm or cold years), redundancy supports the
ability of the species to withstand catastrophic events (for example,
droughts, large pollution events), and representation supports the
ability of the species to adapt over time to long-term changes in the
environment (for example, climate changes). In general, the more
resilient and redundant a species is and the more representation it
has, the more likely it is to sustain populations over time, even under
changing environmental conditions. Using these principles, we
identified the species' ecological requirements for survival and
reproduction at the individual, population, and species levels, and
described the beneficial and risk factors influencing the species'
viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical
and current condition of the species' demographics and habitat
characteristics, including an explanation of how the species arrived at
its current condition. The final stage of the SSA involved making
predictions about the species' responses to positive and negative
environmental and anthropogenic influences. Throughout all of these
stages, we used the best available information to characterize
viability as the ability of a species to sustain populations in the
wild over time. We use this information to inform our regulatory
decision.
The following is a summary of the key results and conclusions from
the SSA report; the full SSA report can be found at Docket No. FWS-R3-
ES-2019-0020 on https://www.regulations.gov.

Summary of Biological Status and Threats

In this discussion, we review the biological condition of the
species and its resources, and the threats that influence the species'
current and future condition, in order to assess the species' overall
viability and the risks to that viability.
The primary threat to the future viability of the Big Creek
crayfish and the St. Francis River crayfish is displacement by a
nonnative crayfish species (woodland crayfish). Currently, no means to
slow or stop the spread of the woodland crayfish exist. Contamination
from heavy metal mining and habitat degradation from sedimentation also
affect the species' viabilities. A brief summary of these stressors is
presented below; for a full description of these stressors, refer to
chapter 3 of the SSA report for each species (USFWS 2022, pp. 13-22).

Nonnative Crayfish

The introduction of nonnative crayfish is one of the primary
factors contributing to declining crayfish populations (Taylor et al.
2007, p. 374). Nonnative crayfish species can displace native
crayfishes through competition, differential predation, reproductive
interference or hybridization, disease transmission, or a combination
of these mechanisms (Lodge et al. 2000, pp. 9, 12).

[[Page 25517]]

Reproductive interference in the form of hybridization may be the
main mechanism driving the displacement of the Big Creek crayfish and
the St. Francis River crayfish. Woodland crayfish have been observed
engaging in mating behavior with St. Francis River crayfish (Westhoff
2011, p. 117). There is also genetic evidence of hybridization between
the woodland crayfish and the Big Creek crayfish, as well as between
the woodland crayfish and the St. Francis River crayfish (Fetzner et
al. 2016 pp. 19-26). Alleles from both parental species have been
detected in individuals in areas invaded by the woodland crayfish,
which suggest that both native species readily hybridize with the
woodland crayfish (Fetzner et al. 2016, p. 28). Genetic swamping (a
process by which the local genotype is replaced) appears to be the
mechanism that leads to the eventual full displacement of the native
species of crayfish, as at least some of the hybrid young appear to be
viable (Fetzner et al. 2016, p. 29).
In 1984, the woodland crayfish, endemic to southeastern Missouri,
was first documented in the Upper St. Francis River watershed, which is
outside of its native range (Pflieger 1996, p. 82). It is estimated
that by 2008 (22 years later), the crayfish had invaded 5 to 20 percent
of the total 3,225 rmi in the watershed (DiStefano and Westhoff 2011,
p. 40). Within areas invaded by the woodland crayfish, the distribution
and abundance of the Big Creek crayfish and St. Francis River crayfish
have been substantially impacted. In one stream, the Big Creek crayfish
constituted 87 percent of the crayfish community in areas not invaded
by the woodland crayfish, but only 27 percent in invaded areas
(DiStefano and Westhoff 2011, p. 40). Similarly, the St. Francis
crayfish constituted 50 percent of the crayfish community in uninvaded
areas, but only 13 percent in invaded areas of the stream. In the
invaded areas of these streams, the woodland crayfish had become the
dominant species, constituting 57 to 86 percent of the crayfish
community (DiStefano and Westhoff 2011, p. 40).
The woodland crayfish's impact on abundance of the Big Creek
crayfish and St. Francis River crayfish has resulted in the range
contraction of both of the native species. In one stream, the range of
the Big Creek crayfish contracted 9.1 rmi (14.7 km) from 2004 to 2009,
simultaneously with the woodland crayfish's expansion in the stream
(DiStefano and Westhoff 2011, p. 40). In three other streams, the range
of the St. Francis River crayfish contracted in conjunction with the
woodland crayfish's invasion (Riggert et al. 1999, p. 1999; DiStefano
2008, p. 419).
The known locations of the woodland crayfish are likely an under-
representation of where the species is present in the watershed, given
that: (1) The majority of locations were documented prior to 2010, and
the species can expand at a rate as high as 745 yards (yd) per year
(681 meters (m) per year) in the upstream direction and 2,499 yd per
year (2,285 m per year) in the downstream direction (DiStefano and
Westhoff 2011, pp. 38, 40); and (2) the woodland crayfish has already
been introduced at several locations throughout the watershed and has
likely been introduced at additional, undocumented locations (it is not
feasible to survey every stream throughout the watershed).

Contamination by Heavy Metal Mining

Approximately 22 percent of the Big Creek crayfish's range and 16
percent of the St. Francis River crayfish's range occur in areas with
contaminated soil. Southeastern Missouri has been a primary producer of
lead since the early 1700s, in an area referred to as the Old Lead
Mining Belt, and more recently in an area referred to as the New Lead
Mining Belt. Although most mining ceased in the 1970s, waste from
mining operations is still present in the landscape, resulting in
contamination of fish and other aquatic biota, alteration of fish and
invertebrate communities, and public health advisories against human
consumption of lead-contaminated fish (Czarneski 1985, pp. 17-23;
Schmitt et al. 1993, pp. 468-471). The relocation of mine waste (chat)
throughout the area as topsoil, fill material, and aggregate for roads,
railroads, concrete, and asphalt has further expanded the area of
contamination, as has aerial deposition from heavy metal smelters and
the use of lead mining tailings for agricultural purposes due to their
lime content (NASEM 2017, pp. 25-37). All of these uses have
contributed to contamination of streams in portions of the Upper St.
Francis River watershed. As a result, 24.2 rmi (38.9 km) of the Little
St. Francis River are currently included in the Environmental
Protection Agency's (EPA) 303(d) list of impaired waters for not
meeting water quality standards for lead (EPA 2020, p. 28; MDNR 2020,
p. 8). In 2012, a portion of Big Creek (34.1 rmi; 54.9 km) was added to
the EPA's 303(d) list for not meeting water quality standards for lead
and cadmium. That stream reach recently was removed from the 303(d)
list for lead (in sediment) due to remediation efforts, but 1.8 rmi
(2.9 km) remain listed for cadmium (EPA 2020, p. 16).
Studies conducted in southeastern Missouri and other areas
demonstrate that heavy metal contamination adversely affects riffle-
dwelling crayfish. In a study conducted in a watershed adjacent to that
of the Upper St. Francis River, metal concentrations in crayfish at
sites downstream of mining activities were significantly higher than
those at reference sites (Allert et al. 2008, pp. 100-101).
Significantly lower crayfish densities were observed at sites
downstream of mining activities than those at reference sites,
indicating that metals associated with mining activities have negative
impacts on crayfish populations in Ozark streams (Allert et al. 2008,
p. 100). Similar results were observed in other areas impacted by
mining wastes (including sites in the Upper St. Francis River
watershed), with sites downstream of mining activities having
significantly higher metal concentrations in crayfish, reduced
densities of crayfish (from 80 to 100 percent) (Allert et al. 2008, pp.
100-101; Allert et al. 2013, p. 567), and significantly lower
survivorship. The mechanisms by which crayfish can be impacted by heavy
metal contamination include interference with orienting (Hubschman
1967, pp. 144-147; Lahman et al. 2015, pp. 443-444), inhibition of
respiration or aerobic metabolism, and increased susceptibility to
predation.

Sedimentation

Crayfish presence is dependent on rocks embedded in little or no
sediment and open interstitial spaces (Loughman et al. 2016, p. 645;
Loughman et al. 2017, p. 5). There is little gravel accumulation in the
Upper St. Francis River watershed due to the surrounding geology.
Streambank soils also are less likely to erode than in most Ozark
streams because of these lower densities of gravel. Thus, stream
channel substrates contain a significant proportion of stable cobble,
stone, and boulders, which provide habitat for crayfishes (Boone 2001,
p. GE1). However, similar to many Ozark streams, streams within the
Upper St. Francis River watershed may experience increased
sedimentation in the future if land uses change or if riparian
corridors are cleared. Three streams within the watershed have
experienced excessive sedimentation due to eroding or breached mine
tailings (Boone 2001, p. WQ4; DiStefano 2008, p. 191). Breaches can
allow a large volume of tailings to enter a stream, such as the 1,500
cubic yd (1,200 cubic m) spilled into a stream

[[Page 25518]]

in 1992 (Boone 2001, p. WQ4), and it can take multiple years for the
aquatic community to begin to recover following a breach. Excessive
deposition of fine sediment from tailings or other sources can cover
rocks and cavities used by the Big Creek crayfish and St. Francis River
crayfish as refugia (an area in which a population of organisms can
survive through a period of unfavorable conditions). The loss of
refugia likely results in reduced foraging habitat, thereby reducing
carrying capacity and the density of subpopulations. The loss of
refugia may also increase competition with the woodland crayfish and
potentially facilitate displacement of the Big Creek crayfish and St.
Francis River crayfish. The loss of refugia, caused by sedimentation,
likely also increases predation risk.

Cumulative Effects

In addition to individually affecting the species, it is likely
that several of the risk factors summarized above are acting
synergistically or additively on both species. The combined impact of
multiple stressors is likely more harmful than a single stressor acting
alone. For example, in areas affected by lead mining contamination, the
rate of displacement of Big Creek crayfish and St. Francis River
crayfish by woodland crayfish may increase. Although lead contamination
may have negative effects on woodland crayfish as well, we anticipate
cumulative synergistic effects in areas where woodland crayfish have
invaded and lead mining contamination is present. Additionally, in
areas invaded by the woodland crayfish, the loss of refugia from
sedimentation may increase competition between the native species and
the woodland crayfish. The combination of stressors acting on the Big
Creek crayfish and the St. Francis River crayfish will likely impact
them more severely in combination than any one factor alone.
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.

Conservation Efforts and Regulatory Mechanisms

Monitoring and research on the Big Creek crayfish and St. Francis
River crayfish have been conducted by the Missouri Department of
Conservation (MDC) and various other organizations. Multiple
evaluations of effects from lead mining contamination on crayfish,
including the St. Francis River crayfish, have been conducted by the
U.S. Geological Survey (USGS). Monitoring efforts benefit conservation
efforts of the Big Creek crayfish and St. Francis River crayfish by
providing information on population health and trends and on the
magnitude and extent of threats; research efforts provide information
on mechanisms by which threats may impact the native crayfishes.
To help curtail the spread of nonnative crayfish in Missouri, MDC
amended the Wildlife Code of Missouri (Missouri Code) in 2011-2012, to
increase regulations pertaining to the sale, purchase, and import of
live crayfishes. While the virile crayfish (Faxonius virilis) may still
be commercially sold in the State for live bait, all other live
crayfishes can be imported, sold, or purchased in Missouri only for the
purposes of human consumption or as food for captive animals kept by
authorized entities (for example, research institutions/agencies,
publicly owned zoos) (Missouri Code of State Regulations 2018b, pp. 6-
7). This State regulation effectively bans the sale and purchase of
live crayfish for bait, the import and sale of live crayfishes in pet
stores, and the purchase and import of live crayfishes by schools for
classroom study, all of which are vectors for crayfish invasions. It is
also illegal in Missouri to release any baitfish or crayfish into
public waters, except as specifically permitted by the MDC (Missouri
Code of State Regulations 2018a, p. 3). These State regulations may
help reduce the likelihood of future invasions of nonnative crayfishes
within the Upper St. Francis River watershed. However, as the woodland
crayfish has already been introduced at several locations in the
watershed, these State regulations will not affect the inevitable
spread of that species within the Upper St. Francis River watershed.
Approximately 41 percent of the Upper St. Francis River watershed
is in Federal and State ownership, with the majority managed by the
U.S. Forest Service as part of the Mark Twain National Forest. The U.S.
Forest Service's management efforts benefit stream health by focusing
on riparian protection and control and reduction of sediment entering
streams. Other major public landowners in the watershed include the
MDC, the U.S. Army Corps of Engineers, and the Missouri Department of
Natural Resources. Additionally, 5.3 rmi (8.5 km) of Big Creek are
designated an ``Outstanding State Resource Water.'' Missouri
Outstanding State Resource Waters are high-quality waters with
significant aesthetic, recreational, or scientific value and receive
special protection against degradation in quality (Missouri Code of
State Regulations 2018c, pp. 14, 16). These protections help maintain
water quality and minimize additional sedimentation; therefore, these
protections may maintain the quantity and quality of habitat of the Big
Creek crayfish and St. Francis River crayfish.
The EPA has conducted, and has plans to continue, extensive
remediation efforts in areas of southeastern Missouri impacted by lead
mining, including the Upper St. Francis River watershed (EPA 2017,
entire; EPA 2018b, entire). These efforts include sediment, soil, and
mine waste removal. The EPA also has funded the development of a
watershed master plan for the Little St. Francis River, located in the
upper end of the watershed (EPA 2018a, entire). This plan will identify
sources of pollution (related to lead mining) and measures to reduce
the pollution.

Current Condition of Species

To evaluate the current (and future viability) of the Big Creek
crayfish and the St. Francis River crayfish, we assessed a range of
conditions to allow us to consider the species' resiliency,
representation, and redundancy. For the purposes of this assessment,
populations were delineated using known locations and expanded to a
subwatershed scale As previously stated, we scaled down to a
subpopulation level for analytical purposes, as both species have a
limited number of populations. In the case of the St. Francis River
crayfish, population-level ecology is also species-level ecology
because genetic analyses indicate the entire species exists as a single
population. Scaling down to the subpopulation level allowed us to
better represent and compare groups of individuals at a finer scale. A
summary of the current condition of each species

[[Page 25519]]

is given at the end of this section (Table 1 and Table 2).
The Big Creek crayfish and St. Francis River crayfish currently
occur in 16 subwatersheds. In 2008, it was estimated that the woodland
crayfish occupied 103 to 403 rmi (166 to 649 km) or 5 to 20 percent of
the total 2,004 rmi (3,225 km) in the Upper St. Francis River watershed
(DiStefano and Westhoff 2011, p. 40). Based on known locations of the
woodland crayfish, we know that 5 of the 16 Big Creek crayfish
subwatersheds have been invaded (31 percent) and 4 of the 16 St.
Francis River subwatersheds have been invaded (25 percent). We also
know that the invasion has resulted in extirpation of the Big Creek
crayfish in 9.1 rmi (14.7 km) and of the St. Francis River crayfish in
8.5 rmi (13.7 stream km) (Figure 2). This is likely a sizable
underestimate of the actual extent of both range contractions, given
that data for known native range contractions represent conditions in
only 2 of the 11 streams known to be invaded by the woodland crayfish
(the range contractions for each species occurred in different
streams).
In addition, the known locations of the woodland crayfish depicted
in Figure 2 are likely an under-representation of where the species is
present in the watershed given that (1) the majority of locations were
documented prior to 2010, (2) the species can expand at a rate as high
as 745 yards (y) per year (681 m per year) in the upstream direction
and 2,499 y per year (2,285 m year) in the downstream direction
(DiStefano and Westhoff 2011, pp. 38, 40) and (3) the woodland crayfish
has already been introduced at several locations throughout the
watershed and has likely been introduced at additional, undocumented
locations (it is not feasible to survey every stream throughout the
watershed). Finally, there is currently no means to slow or stop the
spread of the woodland crayfish.
[GRAPHIC] [TIFF OMITTED] TR27AP23.151

Figure 2. Known locations (as of 2018) of the Woodland Crayfish and
stream segments from which the Big Creek Crayfish (BCC; left) and St.
Francis River Crayfish (SFRC; right) have been extirpated due to the
Woodland Crayfish invasion.

To evaluate the current condition of the Big Creek crayfish and St.
Francis River crayfish in terms of the 3Rs, we reviewed available
information on health of the subpopulations and queried species experts
on the species' representation and redundancy. The full explanation of
this analysis can be found in the SSA report; a summary of our
conclusions is given below.
Resiliency
Although the Twelvemile Creek population of the Big Creek crayfish
has not been invaded by the woodland crayfish, the woodland crayfish
has been documented at 30 locations within the Main population, with 5
of the 14 (36 percent) of the population's subwatersheds invaded. Based
on the Big Creek crayfish's range contractions

[[Page 25520]]

and the rate at which the woodland crayfish can expand, we expect that
range contractions are happening throughout the other invaded
subwatersheds. We also conclude that it is likely that St. Francis
River crayfish abundance in the Main population has been substantially
reduced from heavy metal contamination given that 208 rmi (335 km) of
the 940 rmi (1,514 km), or 22 percent, of the population occurs in
areas with heavy metal surface contamination. Studies conducted in
nearby watersheds demonstrate that heavy metal contamination reduces
abundance. These impacts have reduced resiliency of the Main population
and thus resiliency of the Big Creek crayfish has been reduced.
Four of the 16 subwatersheds occupied by the St. Francis River
crayfish (25 percent) have been invaded by the woodland crayfish.
Similar to the Big Creek crayfish, we expect that contractions of the
St. Francis River crayfish are occurring in these areas based on range
contractions documented elsewhere and the rate at which the woodland
crayfish can expand. Resiliency of the St. Francis River crayfish has
been further reduced due to impacts from heavy metal contamination,
with 16 percent of the range occurring in areas with heavy metal
contamination.
The narrow ranges of both the Big Creek crayfish and St. Francis
River crayfish also inherently make them vulnerable to environmental
variation and stochastic events that could affect their entire range
(for example, extreme drought or flooding).
Representation
We consider Big Creek crayfish representation as having healthy
subpopulations in both the Twelvemile Creek population and the Main
population, to maintain the full breadth of adaptive diversity (and,
thus, adaptive capacity). There appears to be gene flow throughout most
of the Big Creek crayfish's range (Fetzner and DiStefano 2008, p. 12).
However, the Big Creek crayfish in the Twelvemile Creek population
contain unique haplotypes (a group of alleles that are inherited from a
single parent) that were not found anywhere else in the watershed
(Fetzner and DiStefano 2008, p. 12). Although the Twelvemile Creek
population is currently not impacted by the woodland crayfish, the
range of the Main population has been reduced due to woodland crayfish
invasion, with 36 percent of the subwatersheds invaded (Table 1 and
Table 2). Therefore, the species may have lost some level of
representation. For the St. Francis River crayfish, we consider
representation as having multiple, healthy subpopulations distributed
across the range of the species to maintain the breadth of adaptive
diversity (that is, throughout its range in the Upper St. Francis River
watershed). Similar to the Big Creek crayfish, some level of
representation of the St. Francis River crayfish may have been lost due
to documented and undocumented range contractions, with 4 of the 16 (25
percent) of the St. Francis River subwatersheds invaded.
Redundancy
For the purposes of the SSA, we define a catastrophic event as a
biotic or abiotic event that causes significant impacts at the
population level such that the population cannot rebound from the
effects or the population becomes highly vulnerable to normal
population fluctuations or stochastic events.
Based on expert input (further described in the SSA report), we do
not consider extreme drought or chemical spills as catastrophic events
that are likely to have catastrophic effects on the Big Creek crayfish
and St. Francis River crayfish at the species-level. While these events
may not have the devastating effects of a catastrophic event, the
occurrence of extreme droughts or chemical spills would reduce
resiliency of the species acting as a stressor on a more localized
scale. These stressors may potentially extirpate or compromise
subpopulations throughout the impacted area (see chapter 3 of the SSA
report). However, both species are inherently vulnerable to extreme
events or large-scale stressors given their small range, and there has
been some reduction of in-population redundancy due to the extirpation
of individuals (and subpopulations) in some areas because of woodland
crayfish invasion.

Table 1--Summary of Big Creek Crayfish's Current Condition
------------------------------------------------------------------------
Assessment of current condition
------------------------------------------------------------------------
Currently Occupied Stream Occurs in approximately 983 rmi (1,581
Distance. km) within 16 subwatersheds. However,
this does not account for documented and
undocumented range contractions that we
expect are occurring in 31 percent of
the species' subwatersheds due to the
woodland crayfish invasion. In addition,
86 rmi (139 km) of stream reaches are
likely occupied intermittently by the
species due to movement among occupied
watersheds.
Health of Subpopulations..... In areas invaded by the woodland crayfish
(31 percent of occupied subwatersheds),
abundance is substantially reduced, with
the species completely extirpated in
some invaded areas. In areas impacted by
lead mining contamination (22 percent of
the range), abundance is also likely
reduced. In areas not invaded by the
woodland crayfish or impacted by lead
mining contamination, we presume
subpopulations are healthy.
Health of Populations........ We presume the Twelvemile Creek
population is currently healthy because
it does not appear that the woodland
crayfish has invaded the population and
the population is outside of the area of
lead mining contamination. The health of
the Main population, however, has been
impacted due to documented and
undocumented range contractions from the
woodland crayfish invasion in 36 percent
of the population's subwatersheds.
Abundance has also likely been reduced
in 22 percent of the Main population due
to heavy metal contamination.
Resiliency................... Reduced due to documented and
undocumented range contractions in 31
percent of the Big Creek crayfish's
subwatersheds and expected reduced
abundance in 22 percent of the range due
to heavy metal contamination.
Representation............... Somewhat reduced ecological diversity due
to documented and undocumented range
contractions in 25 percent of the Big
Creek crayfish's subwatersheds.
Redundancy................... Somewhat reduced due to documented and
undocumented range contractions in 36
percent of subwatersheds in the Main
population. The species is also
inherently vulnerable to some extreme
events given its small range, However,
both populations of the species have a
high level of redundancy relative to
extreme events that affect areas
downstream of the source of the event
(for example, chemical spills) due to
the number of tributaries that they
occupy that would not be downstream of
the event.
------------------------------------------------------------------------

[[Page 25521]]

Table 2--Summary of St. Francis River Crayfish's Current Condition
------------------------------------------------------------------------
Assessment of current condition
------------------------------------------------------------------------
Currently Occupied Stream Occurs in approximately 944 rmi (1,519
Distance. km) within 16 subwatersheds. However,
this does not account for documented and
undocumented range contractions that we
expect are occurring in 25 percent of
the species' subwatersheds due to the
woodland crayfish invasion. In addition,
99 rmi (159 km) of stream reaches are
likely occupied intermittently by the
species due to movement among occupied
watersheds.
Health of Subpopulations..... In areas invaded by the woodland crayfish
(25 percent of occupied subwatersheds),
abundance is substantially reduced, with
the species completely extirpated in
some invaded areas. In areas impacted by
lead mining contamination (16 percent of
the range), abundance is also likely
reduced. In areas not invaded by the
woodland crayfish or impacted by lead
mining contamination, we presume
subpopulations are healthy.
Resiliency................... Reduced due to documented and
undocumented range contractions in 25
percent of the St. Francis River
crayfish's subwatersheds. Also reduced
due to reduced abundance in 16 percent
of the range due to heavy metal
contamination.
Representation............... Somewhat reduced ecological diversity due
to documented and undocumented range
contractions in 25 percent of the St.
Francis River crayfish's subwatersheds.
Redundancy................... Somewhat reduced due to documented and
undocumented range contractions in 25
percent of the St. Francis River
crayfish's subwatersheds. The species is
also inherently vulnerable to some
extreme events given the species' small
range, and there has been some reduction
in redundancy due to reduction of the
range. However, the species have a high
level of redundancy relative to extreme
events that affect areas downstream of
the source of the event (for example,
chemical spills) due to the number of
tributaries that they occupy that would
not be downstream of the event.
------------------------------------------------------------------------

Future Scenarios

For the purpose of this assessment, we define viability as the
ability of the species to sustain populations in the wild over time. To
evaluate future conditions of the Big Creek crayfish and St. Francis
River crayfish, we predicted the expansion of the nonnative woodland
crayfish within the ranges of the native crayfishes. We asked
biologists with expertise on crayfishes to estimate the future
expansion rate in the Upper St. Francis River watershed, the impact on
Big Creek crayfish and St. Francis River crayfish abundances, and the
length of time for those impacts to be fully realized. A full
description of the expert elicitation meeting methodology and results
are available in the SSA report (Service 2022, pp. 36-47 & 64-70). As a
way to characterize uncertainty in predicting future conditions and to
capture the entire breadth of plausible future conditions, we developed
``reasonable best,'' ``reasonable worst,'' and ``most likely''
scenarios that represent the plausible range of the Big Creek
crayfish's and St. Francis River crayfish's future conditions (see
Table 3, below). Each of the scenarios is based on the expert-elicited
estimates of the woodland crayfish's expansion rates, impacts of the
invasion, and time for impacts to be fully realized. For each of the
scenarios, we predicted the extent of future expansion of the woodland
crayfish at 10, 25, and 50 years into the future. We then calculated
the extent of the Big Creek crayfish's and St. Francis River crayfish's
ranges that would be affected under each scenario and described effects
to abundance based on the experts' projections. Because we used a finer
scale data, we present results in river miles invaded, rather than
subwatersheds invaded (as we did to assess current conditions).
Additional details on the expert elicitation and a summary of results
can be found in appendix B of the SSA report. Below is a summary of the
results from the SSA; for further details on the methods, assumptions,
and results, see chapter 5 of the SSA report. A summary of predicted
impacts in 50 years for both species is summarized in Tables 4 and 5
below.

Table 3--Explanation of Scenarios Used To Predict the Future Condition
of Big Creek Crayfish and St. Francis River Crayfish
------------------------------------------------------------------------
Scenario Estimates used
------------------------------------------------------------------------
Reasonable Best.............. Lowest plausible expansion rate
of the woodland crayfish
Lowest level of predicted
impact on abundance of Big Creek
crayfish and St. Francis River crayfish
Highest number of years for
impacts to be fully realized
Reasonable Worst............. Highest plausible expansion rate
of the woodland crayfish
Highest level of predicted
impact on abundance of Big Creek
crayfish and St. Francis River crayfish
Lowest number of years for
impacts to be fully realized
Most Likely.................. Most likely expansion rate of
the woodland crayfish
Most likely level of predicted
impact on abundance of Big Creek
crayfish and St. Francis River crayfish
Most likely number of years for
impacts to be fully realized
------------------------------------------------------------------------

Big Creek Crayfish

Under the ``reasonable best'' scenario, we expect the woodland
crayfish invasion will expand to 25 percent of the Big Creek crayfish
Main population in 10 years, constituting 24 percent of the species'
range. In 25 years, 35 percent of the Big Creek crayfish Main
population will have been invaded, constituting 33 percent of the
species' range. In 50 years, 49 percent of the Main population will be
invaded, constituting 46 percent of the species' range. The Twelvemile
Creek population is not predicted to be invaded in 25 or 50 years under
this scenario. In areas invaded by the woodland crayfish, abundance is
predicted to be reduced by over 50 percent in 10 to 20 years.
Under the ``reasonable worst'' scenario, we expect 44 percent of
the Main population and 0.2 percent of the Twelvemile Creek population
will be invaded by the woodland crayfish in 10 years, constituting 42
percent of the Big Creek crayfish's total range. In 25 years, 70
percent of the Main population and 81 percent of the Twelvemile Creek
population will be invaded by the woodland crayfish, constituting 70
percent of the Big Creek crayfish's total range. In 50 years, 90
percent of the Main population and 100 percent of the Twelvemile Creek
population will be invaded, constituting 91 percent of the species'
range. In areas invaded by the woodland crayfish, abundance is

[[Page 25522]]

predicted to be reduced by approximately 100 percent (that is,
extirpation) in less than 10 years.
Under the ``most likely'' scenario, we expect 28 percent of the Big
Creek crayfish Main population will be invaded by the woodland crayfish
in 10 years, constituting 27 percent of the species' range. In 25
years, 44 percent of the Main population and 6 percent of the
Twelvemile Creek population will be invaded by the woodland crayfish,
constituting 42 percent of the Big Creek crayfish's total range. In 50
years, 64 percent of the Main population and 56 percent of the
Twelvemile Creek population will be invaded, constituting 64 percent of
the species' range. The best available information indicates that once
an area is invaded by the woodland crayfish, the Big Creek crayfish
will be extirpated within 10 years.
Given that there are currently no known feasible measures to
curtail the woodland crayfish invasion for the long term, we consider
it extremely likely that the invasion will continue. Based on our use
of expert-elicited estimates of the rate of expansion and the resulting
impacts on the Big Creek crayfish, we are also reasonably certain that
we can predict the plausible range of future conditions within 50
years. Here, we discuss the species' future condition in terms of the
next 50 years (Summarized below in Table 4.); 10- and 25-year future
conditions are discussed (beyond what was stated above) in the SSA
report. As previously stated, resiliency of the Big Creek crayfish has
already been reduced from historical conditions due to range
contractions in 31 percent of occupied subwatersheds caused by invasion
of the woodland crayfish. Resiliency also has likely been reduced due
to lead mining contamination in 22 percent of the crayfish's range.
Using the modeling results (that represent the range of all future
scenarios), we predict that within 50 years resiliency of the species
will continue to be reduced due to a 50 to 100 percent reduction in
abundance in 49 to 90 percent of the Main population and 0 to 100
percent of the Twelvemile Creek population. In addition, if other
threats (aside from woodland crayfish invasion and lead mining
contamination) such as drought, flood events, disease, and degraded
water quality, remain the same or increase, resiliency will be further
reduced by these threats. Thus, our modeled results represent the
minimum amount of the species' range that is expected to be impacted
within 50 years because the decline in resiliency only considers
impacts of the woodland crayfish invasion and none of the other
stressors mentioned above that affect the Big Creek crayfish.
We predict that the Big Creek crayfish will continue to lose
ecological diversity, given the expected expansion of the woodland
crayfish and the resulting impact on subpopulations in both the Main
and Twelvemile Creek populations. Both populations are expected to
experience a 50 to 100 percent reduction in abundance in invaded areas.
For the Twelvemile Creek population, in 50 years there may be as much
as 100 percent of the population's range invaded, whereas up to 90
percent of the Main population's range may be invaded in the same time.
Given the unique haplotypes contained in the Twelvemile Creek
population, the reduced abundance of subpopulations in the majority of
that population, or especially the complete loss of that population,
would represent an appreciable reduction in the species'
representation.
The Big Creek crayfish is inherently vulnerable to extreme events
and other stressors, given the species' small range. There has been
already been some reduction in redundancy due to documented and
undocumented range contractions in 36 percent of subwatersheds in the
Main population. Based on results of the future scenario modeling, we
expect that within 50 years, redundancy of the Big Creek crayfish will
be further reduced by the predicted 50 to 100 percent reduction in
abundance in 49 to 90 percent of the range of the Main population and 0
to 100 percent of the range of the Twelvemile Creek population. Because
the Twelvemile Creek population consists of only one subwatershed, it
will be more vulnerable to extreme events if multiple sub-tributaries
are impacted by the woodland crayfish invasion.

St. Francis River Crayfish

Under the ``reasonable best'' scenario, we expect 12 percent of the
St. Francis River crayfish's range will be invaded by the woodland
crayfish in 10 years. In 25 years, 21 percent of the range will have
been invaded, and 33 percent of the range will have been invaded in 50
years. In areas where the woodland crayfish has invaded, abundance is
predicted to be reduced by over 10 to 50 percent in 30 to 40 years.
Under the ``reasonable worst'' scenario, we expect 30 percent of
the St. Francis River crayfish's range will be invaded by the woodland
crayfish in 10 years. In 25 years, 56 percent of the range will have
been invaded, and 81 percent of the range will have been invaded in 50
years. In areas where the woodland crayfish has invaded, abundance is
predicted to be reduced by approximately 100 percent (that is,
extirpation) in less than 10 years.
Under the ``most likely'' scenario, we expect 18 percent of the St.
Francis River crayfish's range will be invaded by the woodland crayfish
in 10 years. In 25 years, 32 percent of the range will have been
invaded, and 50 percent of the range will have been invaded in 50
years. In areas where the woodland crayfish has invaded, abundance is
predicted to be reduced by 50 to 100 percent in 10 to 30 years (Table
5).
Similar to the Big Creek crayfish, we are also reasonably certain
that we can predict the plausible range of future conditions for the
St. Francis River crayfish within 50 years because there are no known
feasible measures to curtail the spread of the woodland crayfish. Here,
we discuss the species' future condition over the next 50 years; 10-
and 25-year future conditions are discussed (beyond what was stated
above) in the SSA report. As previously stated, resiliency of the St.
Francis River crayfish has already been reduced from historical
conditions due to effects of the woodland crayfish invasion in 25
percent of subwatersheds occupied by the St. Francis River crayfish and
also from lead mining contamination in 22 percent of the species'
range. Based on the modeling results (the range of all future
scenarios), we predict that resiliency of the species will continue to
be reduced due to the woodland crayfish invasion and resulting 10 to
100 percent reduction in abundance in an estimated 33 to 81 percent of
the range within 50 years. If threats other than the woodland crayfish
and lead mining contamination, such as drought, flood events, disease
and degraded water quality remain the same or increase, resiliency will
be further reduced. Like the Big Creek crayfish, our modeled results
represent the minimum amount of the species' range that is expected to
be impacted within 50 years because the decline in resiliency only
considers impacts of the woodland crayfish invasion and none of the
other stressors mentioned above that affect the St. Francis River
crayfish.
There has already been some loss in St. Francis River crayfish's
representation due to the loss of the subpopulations (and therefore
ecological diversity) impacted by the woodland crayfish invasion and
impacts of lead mining contamination. The reduction in representation
is expected to continue given the predicted 10 to 100 percent reduction
in abundance in 33 to 81 percent of the species' range,

[[Page 25523]]

based on the results of all future scenarios.
The St. Francis River crayfish is inherently vulnerable to extreme
events and stressors, given the species' small range and single
population, and there has been some reduction in redundancy due to
range reduction and reduced abundance of subpopulations due to the
woodland crayfish invasion and lead mining contamination. Similar to
representation, we expect that redundancy of the St. Francis River
crayfish will be further reduced by the predicted 10 to 100 percent
reduction in abundance in 33 to 81 percent of the species' range within
50 years as more tributaries are invaded and subpopulations are
extirpated.

Table 4--The Range of Predicted Impacts to the Big Creek Crayfish From the Woodland Crayfish at 50 Years Based
on Expert Input
----------------------------------------------------------------------------------------------------------------
Reasonable best Most likely Reasonable worst
(percent) (percent) (percent)
----------------------------------------------------------------------------------------------------------------
Percent of Main population invaded..................... 48.7 64.1 90.4
Percent of Twelvemile Creek population invaded......... 0 55.6 100
Percent of total range invaded......................... 46.2 63.7 90.9
Percent reduction in abundance in invaded areas........ >50 ~100 ~100
----------------------------------------------------------------------------------------------------------------

Table 5--The Range of Predicted Impacts to the St. Francis River Crayfish From the Woodland Crayfish at 50 Years
Based on Expert Input
----------------------------------------------------------------------------------------------------------------
Reasonable best Most likely Reasonable worst
(percent) (percent) (percent)
----------------------------------------------------------------------------------------------------------------
Percent of range invaded............................... 33.2 49.5 81.0
Percent reduction in abundance in invaded areas........ 10 to 50 50 to 100 ~100
----------------------------------------------------------------------------------------------------------------

Summary of Comments and Recommendations

In the proposed rule published on September 17, 2020 (85 FR 58192),
we requested that all interested parties submit written comments on the
proposal by November 16, 2020. We also contacted appropriate Federal
and State agencies, scientific experts and organizations, and other
interested parties and invited them to comment on the proposal.
Newspaper notices inviting public comment were published in the
Democratic News (October 7, 2020) and the Farmington Press (October 1,
2020). After receiving a request for a public hearing, we reopened the
public comment period on April 27, 2021 (86 FR 22127) and requested
that all interested parties submit their comments by May 27, 2021. We
held a virtual public informational meeting followed by a public
hearing on May 13, 2021. All substantive information received during
both comment periods has either been incorporated directly into this
final determination or is addressed below.

Peer Reviewer Comments

As discussed in Supporting Documents, above, we received comments
from one peer reviewer. We reviewed all comments we received from the
peer reviewer for substantive issues regarding the information
contained in the SSA report and new information about the species. The
peer reviewer generally concurred with our methods and conclusions and
provided additional information, clarifications, and suggestions to
improve the final SSA report. Peer reviewer comments were incorporated
into the final SSA report as appropriate.

Public Comments

(1) Comment: Commenters stated that the Service should consider
best management practices (BMPs) for forestry activities in the
assessment of conservation efforts benefitting the species and account
for these beneficial actions in any analyses conducted on the species'
status.
Our Response: To assess the conservation benefit provided by the
forestry BMPs, we considered the extent to which the BMPs are
implemented within the two crayfishes' ranges. Based on information
from surrounding States, the implementation rate of BMPs in Missouri is
estimated to be 82 percent, with the rate representing the number of
sites at which forestry BMPs were applied correctly or where major
water quality impacts were avoided (Ice et al. 2010, p. 272). However,
actual rates for Missouri are not available, as implementation of
forestry BMPs is not required or monitored (NASF 2019, p. 3). In
particular, we have no information to determine whether the estimate in
Ice et al. (2010, p. 272) is applicable within the ranges of the two
crayfishes. Because we are not able to confidently assess the extent to
which implementation of forestry BMPs is benefitting the species, we
did not factor the conservation benefits of BMPs into the analysis
conducted on the species' status. Should we obtain data on BMP
implementation rates within the species' ranges, we will include that
information in the next revision of the species' SSA report.
(2) Comment: Commenters stated that because the woodland crayfish
is native to other watersheds in Missouri, it should not be referred to
as a nonnative species and should not be considered a threat to the Big
Creek crayfish or St. Francis River crayfish.
Our Response: Because the woodland crayfish is not endemic (native)
to the Upper St. Francis River watershed, we consider it accurate to
refer to the species as nonnative in the watershed. We also consider it
accurate to characterize the woodland crayfish as a threat to the Big
Creek crayfish and St. Francis River crayfish given the documented
declines in their abundance in stream reaches invaded by the woodland
crayfish.
(3) Comment: Commenters believe there are no data to support that
hybridization with the woodland crayfish is detrimental to the Big
Creek crayfish and St. Francis River crayfish.
Our Response: Although some of the hybrid individuals appear to be
viable, alleles (versions of a gene) from the Big Creek crayfish and
St. Francis River crayfish are typically absent at most or all of the
loci (specific physical locations of genes or other DNA sequences on a
chromosome) of the hybrid individuals (Fetzner et al. 2016, p. 29). The
low frequency of alleles from

[[Page 25524]]

the native crayfishes indicates that individuals with the native
crayfish alleles are experiencing lower survivorship and/or
reproduction than crayfish with the woodland crayfish alleles. Thus,
the distribution of alleles within stream reaches invaded by the
woodland crayfish is expected to shift towards the alleles of the
woodland crayfish and away from those of the Big Creek crayfish and St.
Francis River crayfish.
(4) Comment: Historical mining activities within the Upper St.
Francis River watershed are not negatively affecting crayfish if the
woodland crayfish is expanding its range within the watershed.
Our Response: The woodland crayfish's expansion in the watershed
has been documented in areas other than those with heavy metal
contamination. Therefore, it is possible for woodland crayfish
abundance to be reduced in contaminated stream reaches while
simultaneously expanding its range within the rest of the watershed.
(5) Comment: A commenter said remediation activities for heavy
metal contamination have improved water quality in certain areas of the
crayfishes' ranges from historical conditions. Therefore, the Service's
assertion that heavy metal mining activities have affected crayfish
abundance is not supported.
Our Response: Remediation activities have improved water quality in
some areas of the crayfishes' ranges. However, we expect that abundance
is still lower in these areas due to the time required for crayfishes
to repopulate the affected stream reaches. In addition, heavy metal
contamination is still present in more than 24 miles of the Little St.
Francis River due to lead and 1.8 miles of Big Creek due to cadmium, as
evidenced by the inclusion of these areas on the EPA's 303(d) list of
impaired waterbodies (EPA 2020, pp. 16, 28).
(6) Comment: A commenter stated results of studies evaluating
effects to crayfish from heavy metal exposure cannot be extrapolated to
areas outside of where the studies were conducted.
Our Response: Various water chemistry parameters, such as water
hardness and alkalinity, can influence bioavailability (the extent to
which a chemical is absorbed) and toxicity of metals. However, heavy
metal concentrations in tissue are representative of bioavailability
since the concentrations represent the amount to heavy metals absorbed
by crayfish. In the northeast portion of the Upper St. Francis River
watershed (within the two crayfishes' ranges), Allert et al. (2016)
documented heavy metal concentrations in crayfish tissue that were
either higher than or comparable to the crayfish tissue concentrations
documented in several of the other studies cited in the SSA report and
the proposed rule (Allert et al. 2008, 2009, 2012). Total chronic toxic
unit scores in the Upper St. Francis River watershed study also were
either higher than or comparable to those in most of the other studies
(Allert et al. 2009, 2012, 2013), with the scores representing the
combined toxicity of metals given water hardness and the extent to
which the metals dissolve in water (making the metals available for
absorption by aquatic species). Lastly, Allert et al. (2016) documented
significantly reduced densities of crayfish, including the St. Francis
River Crayfish, downstream of mining sites and in some areas, a
complete absence of crayfish, providing direct evidence that heavy
metal exposure is negatively affecting crayfish in the Upper St.
Francis River watershed.
(7) Comment: One commenter asserted that contamination due to heavy
metal mining should not be considered a primary threat to the two
crayfishes and that activities related to heavy metal mining should not
be included in the list of prohibitions in the 4(d) rule for the
species because the commenter does not consider it appropriate to use
results of two studies (Allert et al. 2009 and Allert et al. 2010) to
assess impacts to the Big Creek crayfish and St. Francis River crayfish
from heavy metal exposure for reasons detailed below in (7a)-(7e)
Comments. We address this commenter's specific assertions regarding the
use of those two studies below.
(7a) Comment: Physical conditions such as substrate coarseness,
water depth, and current velocity differed between reference and study
sites and could explain the differences in crayfish densities observed.
Our Response: In a separate study, Allert et al. (2008, p. 105),
documented significantly lower crayfish densities at mining sites,
despite mining and reference sites having similar temperature, physical
habitat, and organic matter. Crayfish densities did not correlate with
any of the physical habitat variables that were measured (Allert et al
2008, p. 104). In addition, Allert et al. (2009, pp. 1209, 1213)
documented significantly reduced crayfish survival downstream of mining
sites when caging crayfish in situ (in the wild as opposed to a
laboratory setting) with the same substrate and organic material as
reference sites. These results are consistent with other studies
documenting reduced crayfish densities and survival downstream of
mining sites.
(7b) Comment: Two of the study sites were downstream of a city, and
contaminants other than heavy metals were not assessed. Instead of
heavy metal exposure, inputs from the city's residential, commercial,
and industrial activities, as well as the agricultural uses surrounding
the city, may have caused the reduced crayfish abundance.
Our Response: Multiple studies have demonstrated that, regardless
of proximity to cities, crayfish have elevated heavy metal
concentrations, reduced densities, and reduced survival downstream of
mining sites (Allert et al. 2008, pp. 100-105; Allert et al. 2009, pp.
1210-1213; Allert et al. 2013, pp. 512-515). These results provide
multiple lines of evidence that heavy metal exposure does negatively
affect crayfish, regardless of proximity to cities.
(7c) Comment: Because macroinvertebrate populations vary
significantly over small spatial scales, it cannot be concluded that
heavy metal exposure caused the reduced crayfish abundance at study
sites.
Our Response: As noted above, multiple lines of evidence
demonstrate that heavy metal exposure negatively affects crayfish. The
large number of studies documenting reduced macroinvertebrate
populations downstream of mining sites, combined with heavy metal
concentrations in macroinvertebrates downstream of mining sites,
indicates that heavy metal exposure is responsible for the reduced
crayfish densities downstream of mining sites documented by Allert et
al. (2008, pp. 100-104; 2012, p. 569; 2013, p. 512).
(7d) Comment: Heavy metal levels were measured in fine sediment
obtained from depositional areas. However, crayfish predominantly
occupy riffles. Therefore, it is not appropriate to correlate heavy
metal concentrations in fine sediment with crayfish densities.
Our Response: Allert et al. (2009, p. 1210) and Allert et al.
(2010, p. 8) evaluated heavy metal concentrations in riffle crayfish
tissue as well as in sediment. For both studies, heavy metal
concentrations were higher in sediment and in crayfish tissue
downstream of mining sites, with crayfish downstream of mining sites in
the 2010 study having 100 to 200 times higher concentrations of lead
than crayfish at reference sites (Allert et al. 2010, p. 19). Crayfish
densities were significantly lower in areas with higher heavy metal
concentrations in sediment and also in areas with higher heavy metal

[[Page 25525]]

concentrations in crayfish tissue (Allert et al. 2010, p. 28).
(7e) Comment: To assess heavy metal concentrations in sediment,
Allert et al. (2009 and 2010) sieved the sediment to remove particles
larger than 2 millimeters. The process of sieving the sample to
concentrate sediments biased the sampling results.
Our Response: As noted above, Allert et al. 2010 (entire) assessed
heavy metal concentrations in crayfish as well as in sediment and found
a significant negative correlation of both with crayfish density
(Allert et al. 2010, p. 28). Allert et al. 2009 (p. 1213) also found a
significant negative correlation between heavy metal concentrations in
crayfish and crayfish survival. These results are consistent with other
studies documenting reduced crayfish density in areas downstream of
mining sites. Therefore, negative effects from heavy metal exposure can
be concluded even without the sediment data.
(8) Comment: A public commenter stated that lead is no longer a
concern in Big Creek, and lead is not listed as a pollutant for the
stream on the EPA's current list of impaired streams under section
303(d) of the Clean Water Act (33 U.S.C. 1251 et seq.). Although 1.8
miles of the stream is currently listed for cadmium, the listing is
predominantly based on older data ranging from 2008-2012, and values
only slightly exceed the chronic water quality standard. Therefore,
heavy metal mining should not be included in the list of prohibitions
in the 4(d) rule for the species.
Our Response: We have noted that the extent of Big Creek listed as
impaired under section 303(d) of the Clean Water Act is only 1.8 miles
and that lead is no longer listed as a pollutant for the waterbody.
Because heavy metal contamination remains a factor influencing the
crayfishes elsewhere in the watershed, however, we are retaining heavy
metal mining in the list of prohibitions in the 4(d) rule for the
species.
(9) Comment: A commenter stated the Service should add an exception
to the prohibitions in the proposed 4(d) rule for the discharge or
other introduction of heavy metals conducted in compliance with
relevant Federal and State permits.
Our Response: Under the Act's section 4(d), whenever a species is
listed as a threatened species, the Secretary issues regulations as she
deems necessary and advisable to provide for the conservation of the
listed species. As we discuss above, mining activities can increase
heavy metal exposure in downstream stream reaches, and results of
multiple studies indicate that the heavy metal exposure significantly
reduces crayfish survival and abundance (Allert et al. 2008, pp. 100-
104; 2012, p. 569; 2013, p. 512). Thus, we consider regulating take
from mining activities as necessary and advisable for conserving the
Big Creek crayfish and the St. Francis River crayfish. As such, we
include a prohibition on activities that lead to the introduction of
heavy metals into streams, such as heavy metal mining, in the 4(d) rule
for these species.
(10) Comment: A public commenter stated because the declines of
these two crayfishes appear to be directly attributed to the woodland
crayfish, most of the prohibitions in the 4(d) rule should be removed,
except for those directly aimed at slowing the spread of the woodland
crayfish.
Our Response: Although invasion by the woodland crayfish is the
primary factor causing the species' population declines, additional
stressors that affect crayfishes' reproduction or survival make the
species less viable. Lowered viability, in turn, results in the
crayfishes being more susceptible to displacement by the woodland
crayfish. Therefore, prohibiting take from these additional stressors
will maximize the species' ability to withstand woodland crayfish
invasion. As such, prohibiting take from these additional stressors is
considered necessary and advisable, and these prohibitions are included
in the 4(d) rule for the species.
(11) Comment: One commenter stated that because the woodland
crayfish is the primary factor impacting the two crayfish species, the
critical habitat designation will not help to conserve the species.
Another commenter asserted that, given the economic impact of
designating critical habitat and the minimal conservation benefit, the
Service should not designate critical habitat.
Our Response: Under section 4(a)(3)(A) of the Act, the Secretary
shall, to the maximum extent prudent and determinable, concurrently
with making a determination that a species is an endangered species or
a threatened species, designate critical habitat for that species. We
have determined that designating critical habitat is both prudent and
determinable for the Big Creek crayfish and the St. Francis River
crayfish. Therefore, as required by the Act, we proposed to designate
as critical habitat those areas occupied by the species at the time of
listing and that contain the physical or biological features essential
for the conservation of the species, which may require special
management considerations or protection.
We are making a determination based on the best scientific data
available and after taking into consideration the economic impact, the
impact on national security, and any other relevant impact, of
specifying any particular area as critical habitat, as required by
section 4(b)(2) of the Act. Our consideration of the economic impacts
of the designation are laid out in our economic analysis, as summarized
in a memorandum produced by Industrial Economics, Incorporated (IEc)
(IEc 2019, entire).
We are not relieved of our statutory obligation to designate
critical habitat based on the contention that it will not provide
additional conservation benefit. We also do not agree with the
assertion that critical habitat will not help conserve the species.
Habitat-based threats have been identified as affecting the current and
future conditions of these species. Consultations with Federal agencies
(and those projects with a Federal nexus) will provide additional
conservation benefit. For more information, see the discussion under
Summary of Biological Status and Threats, above. If any area provides
the physical or biological features essential to the conservation of
the species, that area qualifies as critical habitat under the
statutory definition of that term (see section 3(5)(A) of the Act) if
special management considerations or protection are needed.
(12) Comment: One commenter believes the economic analysis for the
proposed designation of critical habitat does not address all of the
incremental costs from the designation, particularly costs to those who
currently discharge to streams occupied by the two species.
Our Response: In our economic analysis, we incorporated the
incremental costs from section 7 consultations associated with the
regulation of discharges in our discussion of the Clean Water Act and
how discharges are regulated. Regardless of the listing status or
designation of critical habitat for the Big Creek crayfish and St.
Francis River crayfish, anyone who wishes to discharge dredge or fill
material into Big Creek crayfish and St. Francis River crayfish habitat
must obtain a permit from the U.S. Army Corps of Engineers (Corps).
Under the Clean Water Act, the EPA also implements pollution control
programs, such as setting standards for wastewater and other point
sources discharges and sets water quality standards for all
contaminants in surface waters. Under section 7 of the Act, Federal
agencies are required to consult with the Service to ensure that

[[Page 25526]]

any action the agencies authorize, fund, or carry out is not likely to
jeopardize the continued existence of any endangered species or
threatened species or result in the destruction or adverse modification
of habitat of such species that is determined by the Secretary to be
critical habitat. Issuance of permits by the Corps, implementation of
pollution control programs by the EPA, and creation of water quality
standards by the EPA all constitute Federal actions and thus require
section 7 consultation on the effects on the species, regardless of
whether critical habitat is designated. The incremental costs (costs
beyond those attributable to a species' listing) associated with
section 7 consultations on critical habitat were found to be limited to
administrative costs. A further explanation of the incremental costs of
section 7 consultations can be found in the screening analysis
memorandum for the Big Creek crayfish and the St. Francis River
crayfish (IEc 2019, section 3).

Determination of Big Creek Crayfish's and St. Francis River Crayfish's
Status

Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species meets the definition of an endangered species or a
threatened species. The Act defines an ``endangered species'' as a
species that is in danger of extinction throughout all or a significant
portion of its range, and a ``threatened species' as a species that is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range. The Act requires
that we determine whether a species meets the definition of endangered
species or threatened species because of any of the following factors:
(A) The present or threatened destruction, modification, or curtailment
of its habitat or range; (B) overutilization for commercial,
recreational, scientific, or educational purposes; (C) disease or
predation; (D) the inadequacy of existing regulatory mechanisms; or (E)
other natural or manmade factors affecting its continued existence.

Status Throughout All of Its Range

After evaluating threats to the species and assessing the
cumulative effect of the threats under the Act's section 4(a)(1)
factors, we found that both the Big Creek crayfish and the St. Francis
River crayfish face threats from a nonnative crayfish invasion (Factor
E) and declines in water quality (due to heavy metal mining,
sedimentation, etc.) (Factor A). These threats continue to impact the
species despite the existing regulatory mechanisms (Factor D) and on-
going conservation efforts. Given current and predicted future
decreases in resiliency, populations will become more vulnerable to
extirpation from stochastic events, thereby resulting in concurrent
losses in representation and redundancy. The range of plausible future
scenarios for the Big Creek crayfish and the St. Francis River crayfish
suggests significant reductions in viability into the future (USFWS
2022, pp. 39-43).
In 2008, the woodland crayfish, which is not native to the Upper
St. Francis River watershed, was estimated to occupy between 103 and
403 rmi (166 to 649 km) in 5 to 20 subwatersheds. Based on known
locations of the woodland crayfish, we know that 5 of the 16 Big Creek
crayfish subwatersheds (31 percent) and 4 of the 16 St. Francis River
crayfish subwatersheds (25 percent) have been invaded. We also know
that the invasion has resulted in extirpation of the Big Creek crayfish
in 9.1 rmi (14.7 km) and the St. Francis River crayfish in 8.5 rmi
(13.7 km). This is likely an underestimate of the actual extent of both
range contractions, given that this represents conditions in only 2 of
the 21 streams and 3 of 9 subwatersheds known to be invaded by the
woodland crayfish (not all known invaded streams and subwatersheds were
surveyed; MDC 2018, unpublished data). In addition, the known locations
of the woodland crayfish are likely an under-representation of where
the species is present in the watershed given that: (1) The majority of
locations were documented prior to 2010; (2) the species can expand at
a rate as high as 745 yd per year (681 m per year) in the upstream
direction and 2,499 yd per year (2,285 m year) in the downstream
direction (DiStefano and Westhoff 2011, pp. 38, 40); (3) the woodland
crayfish has likely been introduced at additional, undocumented
locations (it is not feasible to survey every stream throughout the
watershed); and (4) the invasion has likely progressed since the
development of the SSA report and this final rule because there is
currently no means to slow or stop the spread of the woodland crayfish.
The range of plausible future scenarios for the Big Creek crayfish
and St. Francis River crayfish suggests reduced viability into the
future. Under the ``most likely'' scenarios for both species,
resiliency is expected to decline within 50 years, given that more than
50 percent of streams occupied by the species are predicted to be
invaded by the woodland crayfish. As additional subpopulations become
extirpated, this expected reduction in both the number and distribution
of healthy (and thus sufficiently resilient) subpopulations is likely
to make the species vulnerable to extreme disturbances and
environmental and demographic stochasticity.
Our analysis of the Big Creek crayfish's and the St. Francis River
crayfish's current and future conditions based on the increasing threat
of woodland crayfish invasion and the continuing threat of
contamination, as well as the consideration of conservation efforts
discussed above, indicates that viability for both the Big Creek
crayfish and the St. Francis River crayfish will continue to decline
such that they are likely to become in danger of extinction within the
foreseeable future throughout all of their ranges.
We considered whether these species are presently in danger of
extinction and determined that endangered status is not appropriate.
The current conditions as assessed in the SSA indicate that the species
are abundant in areas not invaded by the woodland crayfish and the
nonnative woodland crayfish has displaced only a portion of both
species in their ranges. Although there are documented declines in
areas that have been invaded by woodland crayfish, both species are
presumed present in over 99 percent of their historical ranges and
these areas are relatively small in comparison to the whole occupied
area (Service 2022, pp. 27-28). Although the species' representation
has declined by some small amount, ecological diversity (and,
therefore, adaptive capacity) likely remains at a level that is
currently adequate. Redundancy has also slightly declined from
historical conditions from a reduction in subpopulations. In short,
while the primary threats are currently acting on the species and many
of those threats are expected to continue or increase into the future,
we did not find that either species is currently in danger of
extinction throughout all of its range.
These declines in the species' viability that are predicted to
occur in the future will put the species in danger of extinction in the
foreseeable future. Thus, after assessing the best available
information, we determine that Big Creek crayfish and St. Francis River
crayfish are not currently in danger of extinction but are likely to
become in danger of extinction within the foreseeable future throughout
all of their ranges.

Status Throughout a Significant Portion of Its Range

Under the Act and our implementing regulations, a species may
warrant

[[Page 25527]]

listing if it is in danger of extinction or likely to become so in the
foreseeable future throughout all or a significant portion of its
range. The court in Center for Biological Diversity v. Everson, 435 F.
Supp. 3d 69 (D.D.C. 2020) (Everson), vacated the aspect of the Final
Policy on Interpretation of the Phrase ``Significant Portion of Its
Range'' in the Endangered Species Act's Definitions of ``Endangered
Species'' and ``Threatened Species'' (Final Policy; 79 FR 37578; July
1, 2014) that provided that the Service does not undertake an analysis
of significant portions of a species' range if the species warrants
listing as threatened throughout all of its range.
Therefore, we proceed to evaluating whether the species is
endangered in a significant portion of its range--that is, whether
there is any portion of the species' range for which both (1) the
portion is significant; and (2) the species is in danger of extinction
in that portion. Depending on the case, it might be more efficient for
us to address the ``significance'' question or the ``status'' question
first. We can choose to address either question first. Regardless of
which question we address first, if we reach a negative answer with
respect to the first question that we address, we do not need to
evaluate the other question for that portion of the species' range.
Following the court's holding in Everson, we now consider whether
there are any significant portions of the species' range where the
species is in danger of extinction now (i.e., endangered). In
undertaking these analyses for Big Creek crayfish and the St. Francis
River crayfish, 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
portions of the range where the species may be endangered.
We evaluated the range of the Big Creek crayfish and the St.
Francis River crayfish to determine if either species is in danger of
extinction now in any portion of their ranges.

St. Francis River Crayfish

The St. Francis River Crayfish is a narrow endemic that functions
as a single population. Thus, there is no biologically meaningful way
to break this limited range into portions, and the threats that this
species faces affect the species throughout its entire range. As a
result, there are no portions of the species' range where the species
has a different biological status from its rangewide biological status.
Therefore, we conclude that there are no portions of this species'
range that warrant further consideration, and the St. Francis River
crayfish is not in danger of extinction in any significant portion of
its range, and we determine that this species is likely to become in
danger of extinction within the foreseeable future throughout all of
its range. This does not conflict with the courts' holdings in Desert
Survivors v. U.S. Department of the Interior, 321 F. Supp. 3d 1011,
1070-74 (N.D. Cal. 2018) and Center for Biological Diversity v. Jewell,
248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, in reaching this
conclusion, we did not apply the aspects of the Final Policy, including
the definition of ``significant'' that those court decisions held to be
invalid.

Big Creek Crayfish

We evaluated the range of the Big Creek crayfish to determine if
the species is in danger of extinction now in any portion of its range.
The range of a species can theoretically be divided into portions in an
infinite number of ways. We focused our analysis on portions of the
species' range that may meet the definition of an endangered species.
For Big Creek crayfish, we considered whether the threats or their
effects on the species are greater in any biologically meaningful
portion of the species' range than in other portions such that the
species is in danger of extinction now in that portion.
The statutory difference between an endangered species and a
threatened species is the time frame in which the species becomes in
danger of extinction; an endangered species is in danger of extinction
now while a threatened species is not in danger of extinction now but
is likely to become so in the foreseeable future. Thus, we reviewed the
best scientific and commercial data available regarding the time
horizon for the threats that are driving the Big Creek crayfish to
warrant listing as a threatened species throughout all of its range. We
then considered whether these threats or their effects are occurring in
any portion of the species' range such that the species is in danger of
extinction now in that portion of its range. We examined the following
threats: effects from the invasion of nonnative crayfish, contamination
by heavy metal mining, and sedimentation, including cumulative effects.
As discussed above, the Big Creek crayfish functions as two
populations: the Main and the Twelvemile populations. The woodland
crayfish has invaded part of (approximately 31 percent) the range of
the Big Creek crayfish but not the Twelvemile population. Because of
this difference in the threats, we evaluated whether or not the Main
population may have a different status from the rest of the range.
Within the Main population, the woodland crayfish has invaded
approximately 36 percent of the range and effects to the species have
begun in those areas. However, declines have not been observed in 64
percent of this population (Table 1) and the woodland crayfish will not
be impacting those areas until the foreseeable future. Abundance in the
Main population has also likely been reduced from heavy metal
contamination given that 22 percent of the population occurs in areas
with heavy metal surface contamination. However, as discussed above,
there are currently multiple healthy subpopulations within the Main
population.
The best scientific and commercial data available indicate that the
time horizon on which the woodland crayfish threat to the species and
the species' responses to this threat are likely to occur is the
foreseeable future. In addition, while there are ongoing threats of
heavy metal contamination within a small area of the Main population,
these combined threats are not causing the Big Creek Crayfish to be in
danger of extinction in the Main population, now. The best scientific
and commercial data available do not indicate that any of the species'
responses to those threats are more immediate in any portions of the
species' range.
Instead, the Big Creek Crayfish is likely to become in danger of
extinction within the foreseeable future due to the demonstrated threat
of the woodland crayfish (and cumulative impacts of other identified
threats) in the future for the Main population and the anticipated
arrival of the woodland crayfish into the Twelvemile population.
Therefore, we determine, that the Big Creek crayfish is likely to
become in danger of extinction within the foreseeable future throughout
all of its range. This does not conflict with the courts' holdings in
Desert Survivors v. U.S. Department of the Interior, 321 F. Supp. 3d
1011, 1070-74 (N.D. Cal. 2018) and Center for Biological Diversity v.
Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, in reaching
this conclusion, we did not apply the aspects of the Final Policy,
including the definition of ``significant'' that those court decisions
held to be invalid.

Determination of Status

Our review of the best scientific and commercial data available
indicates that the Big Creek crayfish and the St. Francis River
crayfish meet the Act's definition of threatened species.

[[Page 25528]]

Therefore, we are listing the Big Creek crayfish and the St. Francis
River crayfish as threatened species in accordance with sections 3(20)
and 4(a)(1) of the Act.

Available Conservation Measures

Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition as a listed
species, planning and implementation of recovery actions, requirements
for Federal protection, and prohibitions against certain practices.
Recognition through listing results in public awareness, and
conservation by Federal, State, Tribal, and local agencies, private
organizations, and individuals. The Act encourages cooperation with the
States and other countries and calls for recovery actions to be carried
out for listed species. The protection required by Federal agencies,
including the Service, and the prohibitions against certain activities
are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Section 4(f) of the Act calls for the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The goal of this process is to restore listed
species to a point where they are secure, self-sustaining, and
functioning components of their ecosystems.
Recovery planning consists of preparing draft and final recovery
plans, beginning with the development of a recovery outline, and making
it available to the public within 30 days of this final listing
determination. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available.
The recovery plan also identifies recovery criteria for review of
when a species may be ready for reclassification from endangered to
threatened (``downlisting'') or removal from protected status
(``delisting''), and methods for monitoring recovery progress. Recovery
plans also establish a framework for agencies to coordinate their
recovery efforts and provide estimates of the cost of implementing
recovery tasks. Recovery teams (composed of species experts, Federal
and State agencies, nongovernmental organizations, and other
conservation partners) are often established to develop recovery plans.
When completed, the recovery outline, draft recovery plan, and the
final recovery plan will be available on our website (https://ecos.fws.gov/ecp/) by searching for each species of crayfish, or from
our Missouri Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their ranges may occur primarily or solely on
non-Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
When this listing becomes effective, funding for recovery actions
will be available from a variety of sources, including Federal budgets,
State programs, and cost-share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. In addition,
pursuant to section 6 of the Act, the State of Missouri will be
eligible for Federal funds to implement management actions that promote
the protection or recovery of the Big Creek crayfish and the St.
Francis River crayfish. Information on our grant programs that are
available to aid species recovery can be found at: https://www.fws.gov/service/financial-assistance.
Please let us know if you are interested in participating in
recovery efforts for the Big Creek crayfish and the St. Francis River
crayfish. Additionally, we invite you to submit any new information on
these species whenever it becomes available and any information you may
have for recovery planning purposes (see FOR FURTHER INFORMATION
CONTACT).
Section 7(a) of the Act requires Federal agencies to evaluate their
actions with respect to any species that is listed as an endangered or
threatened species and with respect to its critical habitat.
Regulations implementing this interagency cooperation provision of the
Act are codified at 50 CFR part 402. Section 7(a)(2) of the Act
requires Federal agencies to ensure that activities they authorize,
fund, or carry out are not likely to jeopardize the continued existence
of any endangered or threatened species or destroy or adversely modify
its critical habitat. If a Federal action may affect a listed species
or its critical habitat, the responsible Federal agency must enter into
consultation with us.
Federal agency actions within the species' habitat that may require
conference or consultation or both as described in the preceding
paragraph may include, but are not limited to, management and any other
landscape-altering activities on Federal lands administered by the
Service, or U.S. Forest Service; issuance of section 404 Clean Water
Act permits by the U.S. Army Corps of Engineers; and construction and
maintenance of roads or highways by the Federal Highway Administration.
It is our policy, as published in the Federal Register on July 1,
1994 (59 FR 34272), to identify to the maximum extent practicable at
the time a species is listed, those activities that would or would not
constitute a violation of section 9 of the Act. The intent of this
policy is to increase public awareness of the effect of a final listing
on proposed and ongoing activities within the range of a listed
species. The discussion below regarding protective regulations under
section 4(d) of the Act complies with our policy.

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

Background

Section 4(d) of the Act contains two sentences. The first sentence
states that the Secretary shall issue such regulations as she deems
necessary and advisable to provide for the conservation of species
listed as threatened. The U.S. Supreme Court has noted that statutory
language like ``necessary and advisable'' demonstrates a large degree
of deference to the agency (see Webster v. Doe, 486 U.S. 592 (1988)).
Conservation is defined in the Act to mean the use of all methods and
procedures which are necessary to bring any endangered species or
threatened species to the point at which the measures provided pursuant
to the Act are no longer necessary. Additionally, the second sentence
of section 4(d) of the Act states that the Secretary may by regulation
prohibit with respect to any threatened species any act prohibited
under section 9(a)(1), in the case of fish or wildlife, or section
9(a)(2), in the case of plants. Thus, the combination of the two
sentences of section 4(d) provides

[[Page 25529]]

the Secretary with wide latitude of discretion to select and promulgate
appropriate regulations tailored to the specific conservation needs of
the threatened species. The second sentence grants particularly broad
discretion to the Service when adopting the prohibitions under section
9.
The courts have recognized the extent of the Secretary's discretion
under this standard to develop rules that are appropriate for the
conservation of a species. For example, courts have upheld rules
developed under section 4(d) as a valid exercise of agency authority
where they prohibited take of threatened wildlife or include a limited
taking prohibition (see Alsea Valley Alliance v. Lautenbacher, 2007
U.S. Dist. Lexis 60203 (D. Or. 2007); Washington Environmental Council
v. National Marine Fisheries Service, 2002 U.S. Dist. Lexis 5432 (W.D.
Wash. 2002)). Courts have also upheld 4(d) rules that do not address
all of the threats a species faces (see State of Louisiana v. Verity,
853 F.2d 322 (5th Cir. 1988)). As noted in the legislative history when
the Act was initially enacted, ``once an animal is on the threatened
list, the Secretary has an almost infinite number of options available
to [her] with regard to the permitted activities for those species.
[She] may, for example, permit taking, but not importation of such
species, or [she] may choose to forbid both taking and importation but
allow the transportation of such species'' (H.R. Rep. No. 412, 93rd
Cong., 1st Sess. 1973).
Exercising our authority under section 4(d), we have developed a
rule that is designed to address the Big Creek crayfish's and the St.
Francis River crayfish's specific threats and conservation needs.
Although the statute does not require us to make a ``necessary and
advisable'' finding with respect to the adoption of specific
prohibitions under section 9, we find that this rule as a whole
satisfies the requirement in section 4(d) of the Act to issue
regulations deemed necessary and advisable to provide for the
conservation of the Big Creek crayfish and the St. Francis River
crayfish. As discussed above under Summary of Biological Status and
Threats, we have concluded that the Big Creek crayfish and the St.
Francis River crayfish are likely to become in danger of extinction
within the foreseeable future primarily due to invasion by the woodland
crayfish, but additionally from the impacts from heavy metal
contamination and sedimentation. The provisions of this 4(d) rule will
promote conservation of the Big Creek crayfish and the St. Francis
River crayfish by discouraging the spread of the woodland crayfish (and
other invasive species) and encouraging management of the landscape in
ways that maintains the health of Big Creek crayfish and St. Francis
River crayfish and conserves the species by maximizing their ability to
withstand the woodland crayfish invasion. The provisions of this rule
are one of many tools that we will use to promote the conservation of
the Big Creek crayfish and the St. Francis River crayfish.
Section 7(a)(2) of the Act requires Federal agencies, including the
Service, to ensure that any action they fund, authorize, or carry out
is not likely to jeopardize the continued existence of any endangered
species or threatened species or result in the destruction or adverse
modification of designated critical habitat of such species.
If a Federal action may affect a listed species or its critical
habitat, the responsible Federal agency (action agency) must enter into
consultation with us. Examples of actions that are subject to the
section 7 consultation process are actions on State, Tribal, local, or
private lands that require a Federal permit (such as a permit from the
U.S. Army Corps of Engineers under section 404 of the Clean Water Act
(33 U.S.C. 1251 et seq.) or a permit from the Service under section 10
of the Act) or that involve some other Federal action (such as funding
from the Federal Highway Administration, Federal Aviation
Administration, or the Federal Emergency Management Agency). Federal
actions not affecting listed species or critical habitat--and actions
on State, Tribal, local, or private lands that are not federally
funded, authorized, or carried out by a Federal agency--do not require
section 7 consultation.
This obligation does not change in any way for a threatened species
with a species-specific 4(d) rule. Actions that result in a
determination by a Federal agency of ``not likely to adversely affect''
continue to require the Service's written concurrence and actions that
are ``likely to adversely affect'' a species require formal
consultation and the formulation of a biological opinion.

Provisions of the 4(d) Rule

This 4(d) rule will provide for the conservation of the Big Creek
crayfish and the St. Francis River crayfish by prohibiting the
following activities, except as otherwise authorized or permitted:
Import or export; take; possession and other acts with unlawfully taken
specimens; delivery, receipt, transport, or shipment in interstate or
foreign commerce in the course of commercial activity; and sale or
offer for sale in interstate or foreign commerce. The 4(d) rule will
also provide for the conservation of the species by the use of other
protective regulations as follows:
As discussed above under Summary of Biological Status and Threats,
the spread of nonnative crayfish (Factor E) and declines in water
quality (due to mining, sedimentation, etc.) (Factor A) are affecting
the status of the Big Creek crayfish and the St. Francis River
crayfish. A range of activities have the potential to impact these
species, including, but not limited to: Recreational activities that
promote the spread of the woodland crayfish; mining (heavy metal and
gravel); wastewater effluent discharge; agricultural activities;
construction of low-water crossings and bridge construction; and
destruction of bank habitat that increases rates of sedimentation.
Regulating take from these activities would help preserve these
species, slow their rate of decline, and decrease synergistic, negative
effects from other stressors.
Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect, or to attempt to engage in any
such conduct. Some of these provisions have been further defined in
regulation at 50 CFR 17.3. Take can result knowingly or otherwise, by
direct and indirect impacts, intentionally or incidentally. Regulating
incidental and intentional take will help discourage the spread of the
woodland crayfish and will maintain or increase water quality to
preserve the Big Creek crayfish and the St. Francis River crayfish,
slow their rate of decline, and decrease synergistic, negative effects
from other stressors.
We may issue permits to carry out otherwise prohibited activities,
including those described above, involving threatened wildlife under
certain circumstances. Regulations governing permits are codified at 50
CFR 17.32. With regard to threatened wildlife, a permit may be issued
for the following purposes: For scientific purposes, to enhance
propagation or survival, for economic hardship, for zoological
exhibition, for educational purposes, for incidental taking, or for
special purposes consistent with the purposes of the Act. The statute
also contains certain exemptions from the prohibitions, which are found
in sections 9 and 10 of the Act.
We recognize the special and unique relationship with our State
natural resource agency partners in contributing to conservation of
listed species. State

[[Page 25530]]

agencies often possess scientific data and valuable expertise on the
status and distribution of endangered, threatened, and candidate
species of wildlife and plants. State agencies, because of their
authorities and their close working relationships with local
governments and landowners, are in a unique position to assist us in
implementing all aspects of the Act. In this regard, section 6 of the
Act provides that we shall cooperate to the maximum extent practicable
with the States in carrying out programs authorized by the Act.
Therefore, any qualified employee or agent of a State conservation
agency that is a party to a cooperative agreement with us in accordance
with section 6(c) of the Act, who is designated by his or her agency
for such purposes, will be able to conduct activities designed to
conserve Big Creek crayfish or St. Francis River crayfish that may
result in otherwise prohibited take without additional authorization.
Additionally, this 4(d) rule also allows a person to take a Big Creek
crayfish or a St. Francis River crayfish if that person is conducting
research or education under a valid Missouri Department of Conservation
Wildlife Collector's permit.
Along with State (and State-sponsored) conservation efforts, a
person may take, incidental to an otherwise lawful activity, a Big
Creek crayfish or a St. Francis River crayfish during restoration
activities or other activities that will result in an overall benefit
to one or both of the species or their habitat. Such activities
include, but are not limited to, heavy metal remediation efforts and
habitat restoration efforts.
Our full 4(d) rule for the Big Creek crayfish and the St. Francis
River crayfish, including all of the prohibitions and exceptions to
prohibitions for these species, is provided below, under Regulation
Promulgation.
Nothing in this 4(d) rule will change in any way the recovery
planning provisions of section 4(f) of the Act, the consultation
requirements under section 7 of the Act, or the ability of the Service
to enter into partnerships for the management and protection of the Big
Creek crayfish and the St. Francis River crayfish. However, interagency
cooperation may be further streamlined through planned programmatic
consultations for the species between Federal agencies and the Service.

III. Critical Habitat

Background

Critical habitat is defined in section 3 of the Act as:
(1) The specific areas within the geographical area occupied by the
species, at the time it is listed in accordance with the Act, on which
are found those physical or biological features
(a) Essential to the conservation of the species, and
(b) Which may require special management considerations or
protection; and
(2) Specific areas outside the geographical area occupied by the
species at the time it is listed, upon a determination that such areas
are essential for the conservation of the species.
Our regulations at 50 CFR 424.02 define the geographical area
occupied by the species as an area that may generally be delineated
around species' occurrences, as determined by the Secretary (i.e.,
range). Such areas may include those areas used throughout all or part
of the species' life cycle, even if not used on a regular basis (e.g.,
migratory corridors, seasonal habitats, and habitats used periodically,
but not solely by vagrant individuals).
Conservation, as defined under section 3 of the Act, means to use
and the use of all methods and procedures that are necessary to bring
an endangered or threatened species to the point at which the measures
provided pursuant to the Act are no longer necessary. Such methods and
procedures include, but are not limited to, all activities associated
with scientific resources management such as research, census, law
enforcement, habitat acquisition and maintenance, propagation, live
trapping, and transplantation, and, in the extraordinary case where
population pressures within a given ecosystem cannot be otherwise
relieved, may include regulated taking.
Critical habitat receives protection under section 7 of the Act
through the requirement that Federal agencies ensure, in consultation
with the Service, that any action they authorize, fund, or carry out is
not likely to result in the destruction or adverse modification of
critical habitat. The designation of critical habitat does not affect
land ownership or establish a refuge, wilderness, reserve, preserve, or
other conservation area. Such designation also does not allow the
government or public to access private lands. Such designation does not
require implementation of restoration, recovery, or enhancement
measures by non-Federal landowners. Where a landowner requests Federal
agency funding or authorization for an action that may affect a listed
species or critical habitat, the Federal agency will be required to
consult with the Service under section 7(a)(2) of the Act. However,
even if the Service were to conclude that the proposed activity would
result in destruction or adverse modification of the critical habitat,
the Federal action agency and the landowner are not required to abandon
the proposed activity, or to restore or recover the species; instead,
they must implement ``reasonable and prudent alternatives'' to avoid
destruction or adverse modification of critical habitat.
Under the first prong of the Act's definition of critical habitat,
areas within the geographical area occupied by the species at the time
it was listed are included in a critical habitat designation if they
contain physical or biological features (1) essential to the
conservation of the species and (2) which may require special
management considerations or protection. For these areas, critical
habitat designations identify, to the extent known using the best
scientific and commercial data available, those physical or biological
features that are essential to the conservation of the species (such as
space, food, cover, and protected habitat).
Under the second prong of the Act's definition of critical habitat,
we can designate critical habitat in areas outside the geographical
area occupied by the species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific data available. Further, our Policy on
Information Standards Under the Endangered Species Act (published in
the Federal Register on July 1, 1994 (59 FR 34271)), the Information
Quality Act (section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)),
and our associated Information Quality Guidelines provide criteria,
establish procedures, and provide guidance to ensure that our decisions
are based on the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific data available, to use primary and original sources
of information as the basis for recommendations to designate critical
habitat.

[[Page 25531]]

When we are determining which areas should be designated as
critical habitat, the primary sources of information are generally
referenced in the SSA report and also include information developed
during the listing process for the species. Additional information
sources may include any generalized conservation strategy, criteria, or
outline that may have been developed for the species; the recovery plan
for the species; articles in peer-reviewed journals; conservation plans
developed by States and counties; scientific status surveys and
studies; biological assessments; other unpublished materials; or
experts' opinions or personal knowledge.
Habitat is dynamic, and species may move from one area to another
over time. We recognize that critical habitat designated at a
particular point in time may not include all of the habitat areas that
we may later determine are necessary for the recovery of the species.
For these reasons, a critical habitat designation does not signal that
habitat outside the designated area is unimportant or may not be needed
for recovery of the species. Areas that are important to the
conservation of the species, both inside and outside the critical
habitat designation, will continue to be subject to: (1) Conservation
actions implemented under section 7(a)(1) of the Act; (2) regulatory
protections afforded by the requirement in section 7(a)(2) of the Act
for Federal agencies to ensure their actions are not likely to
jeopardize the continued existence of any endangered or threatened
species; and (3) the prohibitions found in section 9 of the Act.
Federally funded or permitted projects affecting listed species outside
their designated critical habitat areas may still result in jeopardy
findings in some cases. These protections and conservation tools will
continue to contribute to recovery of this species. Similarly, critical
habitat designations made on the basis of the best available
information at the time of designation will not control the direction
and substance of future recovery plans, habitat conservation plans
(HCPs), or other species conservation planning efforts if new
information available at the time of these planning efforts calls for a
different outcome.

Physical or Biological Features Essential to the Conservation of the
Species

In accordance with section 3(5)(A)(i) of the Act and regulations at
50 CFR 424.12(b), in determining which areas we will designate as
critical habitat from within the geographical area occupied by the
species at the time of listing, we consider the physical or biological
features that are essential to the conservation of the species and that
may require special management considerations or protection. The
regulations at 50 CFR 424.02 define ``physical or biological features
essential to the conservation of the species'' as the features that
occur in specific areas and that are essential to support the life-
history needs of the species, including, but not limited to, water
characteristics, soil type, geological features, sites, prey,
vegetation, symbiotic species, or other features. A feature may be a
single habitat characteristic or a more complex combination of habitat
characteristics. Features may include habitat characteristics that
support ephemeral or dynamic habitat conditions. Features may also be
expressed in terms relating to principles of conservation biology, such
as patch size, distribution distances, and connectivity. For example,
physical features essential to the conservation of the species might
include gravel of a particular size required for spawning, alkaline
soil for seed germination, protective cover for migration, or
susceptibility to flooding or fire that maintains necessary early-
successional habitat characteristics. Biological features might include
prey species, forage grasses, specific kinds or ages of trees for
roosting or nesting, symbiotic fungi, or a particular level of
nonnative species consistent with conservation needs of the listed
species. The features may also be combinations of habitat
characteristics and may encompass the relationship between
characteristics or the necessary amount of a characteristic essential
to support the life history of the species.
In considering whether features are essential to the conservation
of the species, we may consider an appropriate quality, quantity, and
spatial and temporal arrangement of habitat characteristics in the
context of the life-history needs, condition, and status of the
species. These characteristics include, but are not limited to, space
for individual and population growth and for normal behavior; food,
water, air, light, minerals, or other nutritional or physiological
requirements; cover or shelter; sites for breeding, reproduction, or
rearing (or development) of offspring; and habitats that are protected
from disturbance.

Summary of Essential Physical or Biological Features

We derive the specific physical or biological features essential to
the conservation of Big Creek crayfish and St. Francis River crayfish
from studies of the species' habitat, ecology, and life history, and
describe them below. Additional information can be found in the SSA
report (Service 2022, entire) or the proposed rule (85 FR 58192), both
documents are available on https://www.regulations.gov under Docket No.
FWS-R3-ES-2019-0020). We have determined that the following physical or
biological features are essential to the conservation of Big Creek
crayfish and St. Francis River crayfish:
(1) Stream flow velocity generally between 0 and 1.1 feet per
second (ft/s) (0 and 0.35 meters per second (m/s)).
(2) Stream depths generally between 0.2 and 1.6 ft (0.06 and 0.49
m) for the Big Creek crayfish, and stream depths generally between 0.2
and 1.7 ft (0.06 and 0.52 m) for the St. Francis River crayfish.
(3) Water temperatures between 34 and 84 degrees Fahrenheit
([deg]F) (1.1 and 28.9 degrees Celsius ([deg]C)).
(4) Adequately low stream embeddedness so that spaces under rocks
and cavities in gravel remain available to the Big Creek crayfish and
St. Francis River crayfish.
(5) An available forage and prey base consisting of invertebrates,
periphyton, and plant detritus.
(6) Connectivity among occupied stream reaches of the Big Creek
crayfish (both within and among occupied subwatersheds), and
connectivity among occupied stream reaches of the St. Francis River
crayfish (both within and among occupied subwatersheds).
(7) Ratios or densities of nonnative species low enough to allow
for maintaining the populations of the Big Creek crayfish and St.
Francis River crayfish.

Special Management Considerations or Protection

When designating critical habitat, we assess whether the specific
areas within the geographical area occupied by the species at the time
of listing contain features that are essential to the conservation of
the species and which may require special management considerations or
protection. The features essential to the conservation of the Big Creek
crayfish and St. Francis River crayfish may require special management
considerations or protections to reduce the following threats: (1)
Facilitated movement of nonnative crayfish (for example, bait bucket
dumping); (2) nutrient pollution that impacts water quantity and
quality, including, but not limited to, agricultural runoff and
wastewater effluent; (3) significant alteration of water quality (for
example, heavy metal contamination); (4) forest management

[[Page 25532]]

or silviculture activities that do not implement State-approved best
management practices (BMPs) such that riparian corridors are impacted
or sedimentation is increased; (5) sedimentation from construction of
dams, culverts, and low water crossings that do not allow for the
passage of species or materials, and pipeline and utility installation
that creates barriers to movement; and (6) other watershed and
floodplain disturbances that release sediments or nutrients into the
water.
Management activities that could ameliorate these threats include,
but are not limited to: Education to encourage responsible and legal
bait use and proper disposal of unused bait; use of BMPs designed to
reduce sedimentation, erosion, and bank side destruction; protection of
riparian corridors and retention of sufficient canopy cover along
banks; moderation of surface and ground water withdrawals to maintain
natural flow regimes; increased use of stormwater management and
reduction of stormwater flows into the systems; remediation of
contaminated stream reaches and eroding stream banks; and reduction of
other watershed and floodplain disturbances that release sediments,
pollutants, or nutrients into the water.

Criteria Used To Identify Critical Habitat

As required by section 4(b)(2) of the Act, we use the best
scientific data available to designate critical habitat. In accordance
with the Act and our implementing regulations at 50 CFR 424.12(b), we
review available information pertaining to the habitat requirements of
the species and identify specific areas within the geographical area
occupied by the species at the time of listing and any specific areas
outside the geographical area occupied by the species to be considered
for designation as critical habitat. We are not designating any areas
outside the geographical areas occupied by the species because we have
not identified any unoccupied areas that meet the definition of
critical habitat and we have determined that designating the occupied
areas is sufficient to conserve the Big Creek crayfish and the St.
Francis River crayfish.
We anticipate that recovery will require continued protection of
existing populations and habitat, as well as ensuring there are
adequate numbers of Big Creek crayfish and St. Francis River crayfish
in stable subpopulations and that these subpopulations occur over a
wide geographic area. This strategy will help to ensure that extreme
events, such as the effects of flooding (for example, flooding that
causes excessive sedimentation, nutrients, and debris to disrupt stream
ecology), droughts, or chemical spills, cannot simultaneously affect
all known subpopulations. The following rangewide potential recovery
actions were considered in formulating this designation of critical
habitat: (1) Mitigating or minimizing the effects of the spread of
woodland crayfish, preventing additional introductions of woodland
crayfish (and other nonnative species), investigating methods to slow
or halt the expansion of woodland crayfish, and investigating methods
of eradicating woodland crayfish; (2) maintaining the quality and
quantity of habitat (including, but not limited to, preventing
increased sedimentation rates); (3) preventing additional heavy metal
contamination and remediating previous heavy metal contamination; (4)
investigating other water quality issues that may impact crayfish
abundance; and (5) minimizing loss of rangewide genetic diversity by
maintaining adequate population sizes, distribution, and connectivity.
Sources of data for these designations of critical habitat include
the Missouri Department of Conservation, National Hydrography Dataset
Plus (for mapping purposes), published literature, survey reports on
water quality in various streams within the species' ranges (for more
information, see the SSA report), and the proposed rule (85 FR 58192;
September 17, 2020). We have also reviewed available information that
pertains to the habitat requirements of this species. Sources of
information on habitat requirements include studies conducted at
occupied sites and published in peer-reviewed articles, agency reports,
and data collected during monitoring efforts (see the SSA report:
Service 2022). We have also reviewed all comments submitted by the
public during two public comment periods on the proposed rule (see 85
FR 58192, September 17, 2020, and 86 FR 22127, April 27, 2021).
We consider the areas occupied at the time of listing to include
all streams within occupied subwatersheds (at the 12-digit hydrologic
unit level). Occupied watersheds were determined using data from the
Missouri Department of Conservation. For the purposes of designating
critical habitat, we also consider stretches of the St. Francis River
between subwatersheds as occupied migratory corridors, based on genetic
analyses that indicate there is gene flow among subwatersheds.
Based on this information, we consider all streams within the
following subwatersheds in the Upper St. Francis River watershed to be
currently occupied by the Big Creek crayfish at the time of this final
listing (numbers in parentheses represent the 12-digit hydrologic
codes): Big Lake Creek-St. Francis River (080202020503), Blankshire
Branch-St. Francis River (080202020204), Captain Creek-St. Francis
River (080202020405), Cedar Bottom Creek-St. Francis River
(080202020402), Clark Creek (080202020407), Cedar Bottom Creek
(080202020501), Crane Pond Creek (080202020303), Headwaters St. Francis
River (080202020201), Headwaters Twelvemile Creek (080202020403),
Leatherwood Creek-St. Francis River (080202020406), Lower Big Creek
(080202020304), Middle Big Creek (080202020302), Saline Creek-Little
St. Francis River (080202020102), Turkey Creek-St. Francis River
(080202020210), Twelvemile Creek (080202020404), and Upper Big Creek
(080202020301). We also consider the entire St. Francis River upstream
of 37.091254N, 90.447212W to be occupied, as genetic analyses indicate
gene flow among the subwatersheds.
For the St. Francis River crayfish, we consider all streams within
the following subwatersheds to be currently occupied at the time of
listing: Blankshire Branch-St. Francis River (80202020204), Captain
Creek-St. Francis River (80202020405), Cedar Bottom Creek-St. Francis
River (80202020402), Headwaters St. Francis River (80202020201),
Headwaters Stouts Creek (80202020207), Hubble Creek-St. Francis River
(80202020502), Leatherwood Creek-St. Francis River (80202020406),
Little St. Francis River (80202020103), Lost Creek (80202020507),
Marble Creek (80202020401), Musco Creek-Little St. Francis River
(80202020101), O'Bannon Creek-St. Francis River (80202020206), Saline
Creek-Little St. Francis River (80202020102), Stouts Creek
(80202020208), Turkey Creek-St. Francis River (80202020210), and
Wachita Creek-St. Francis River (80202020209). We also consider the
entire St. Francis River upstream of 36.982104N, 90.335400W to be
currently occupied, given that genetic analyses indicate gene flow
among subwatersheds. The final critical habitat designation for each
species includes all known currently occupied streams within the
historical range, as well as those that connect occupied streams that
contain the physical or biological features that will allow for the
maintenance and expansion of existing populations and movement between
them. See Final Critical Habitat

[[Page 25533]]

Designations, below, for a more detailed explanation of the units.
When determining critical habitat boundaries, we made every effort
to avoid including developed areas such as lands covered by buildings,
pavement, and other structures because such lands lack physical or
biological features necessary for Big Creek crayfish and the St.
Francis River crayfish. The scale of the maps we prepared under the
parameters for publication within the Code of Federal Regulations may
not reflect the exclusion of such developed lands. Any such lands
inadvertently left inside critical habitat boundaries shown on the maps
of this rule have been excluded by text in the rule and are not
designated as critical habitat. Therefore, a Federal action involving
these lands will not trigger section 7 consultation with respect to
critical habitat and the requirement of no adverse modification unless
the specific action will affect the physical or biological features in
the adjacent critical habitat.
We are designating as critical habitat areas that we have
determined are occupied at the time of listing (i.e., currently
occupied) and that contain one or more of the physical or biological
features that are essential to support life-history processes of the
species.
We are designating one critical habitat unit for each species, for
a total of two units for both species, based on one or more of the
physical or biological features being present to support the Big Creek
crayfish or St. Francis River crayfish's life-history processes. All
units are occupied and contain one or more of the identified physical
or biological features and support multiple life-history processes.
The critical habitat designations are defined by the map or maps,
as modified by any accompanying regulatory text, presented at the end
of this document under Regulation Promulgation. We include more
detailed information on the boundaries of each critical habitat
designation in the preamble of this document. We will make the
coordinates or plot points or both on which each map is based available
to the public on https://www.regulations.gov at Docket No. FWS-R3-ES-
2019-0020 and at the field office responsible for the designation (see
FOR FURTHER INFORMATION CONTACT).

Final Critical Habitat Designations

We are designating one unit for each species, for a total of two
units for both species, as critical habitat for the Big Creek crayfish
and the St. Francis River crayfish. The critical habitat areas we
describe below constitute our current best assessment of areas that
meet the definition of critical habitat for Big Creek crayfish and St.
Francis River crayfish. We are designating approximately 1,069 rmi
(1,720 km) of critical habitat in one unit for Big Creek crayfish. We
are designating approximately 1,043 rmi (1,679 km) of critical habitat
in another unit for the St. Francis River crayfish. Tables 6 and 7
provide information on the approximate area of each unit and the
adjacent land ownership. Because all streambeds are navigable waters,
both critical habitat units are managed by the State of Missouri. The
units include stream habitat up to bank full height. We are not
designating any adjacent land as critical habitat.

Table 6--Critical Habitat Unit for Big Creek Crayfish
------------------------------------------------------------------------
Stream miles
Adjacent land ownership (kilometers)
------------------------------------------------------------------------
Federal................................................. 296 (476)
State................................................... 42 (68)
Private................................................. 730 (1,175)
---------------
Total............................................... 1,069 (1,720)
------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding.

Table 7--Critical Habitat Unit for St. Francis River Crayfish
------------------------------------------------------------------------
Stream miles
Adjacent land ownership (kilometers)
------------------------------------------------------------------------
Federal................................................. 329 (529)
State................................................... 22 (35)
Private................................................. 693 (1,115)
---------------
Total............................................... 1,043 (1,679)
------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding.

We present brief descriptions of both units, and reasons why each
one meets the definition of critical habitat for Big Creek crayfish or
St. Francis River crayfish, below.

Big Creek Crayfish Unit

The Big Creek crayfish unit consists of approximately 1,069 rmi
(1,720 km) in the Upper St. Francis River watershed upstream of
Wappapello Dam in Iron, Madison, St. Francois, Washington, and Wayne
Counties in Missouri. The unit consists of all of the streams in the
following 12-digit hydrologic units: Big Lake Creek-St. Francis River
(080202020503), Blankshire Branch-St. Francis River (080202020204),
Captain Creek-St. Francis River (080202020405), Cedar Bottom Creek-St.
Francis River (080202020402), Clark Creek (080202020407), Cedar Bottom
Creek (080202020501), Crane Pond Creek (080202020303), Headwaters St.
Francis River (080202020201), Headwaters Twelvemile Creek
(080202020403), Leatherwood Creek-St. Francis River (080202020406),
Lower Big Creek (080202020304), Middle Big Creek (080202020302), Saline
Creek-Little St. Francis River (080202020102), Turkey Creek-St. Francis
River (080202020210), Twelvemile Creek (080202020404), and Upper Big
Creek (080202020301). The unit also consists of the entire St. Francis
River upstream of 37.091254N, 90.447212W. The unit does not include any
areas of adjacent land. A large portion of the riparian land adjacent
to streams in this unit is privately owned (68 percent), with 28
percent in Federal ownership and 4 percent in State ownership.

St. Francis River Crayfish Unit

The St. Francis River crayfish unit consists of approximately 1,043
rmi (1,679 km) in the Upper St. Francis River watershed upstream of
Wappapello Dam in Iron, Madison, St. Francois, Washington, and Wayne
Counties in Missouri. The unit consists of all of the streams in the
following 12-digit hydrologic units: Blankshire Branch-St. Francis
River (80202020204), Captain Creek-St. Francis River (80202020405),
Cedar Bottom Creek-St. Francis River (80202020402), Headwaters St.
Francis River (80202020201), Headwaters Stouts Creek (80202020207),
Hubble Creek-St. Francis River (80202020502), Leatherwood Creek-St.
Francis River (80202020406), Little St. Francis River (80202020103),
Lost Creek (80202020507), Marble Creek (80202020401), Musco Creek-
Little St. Francis River (80202020101), O'Bannon Creek-St. Francis
River (80202020206), Saline Creek-Little St. Francis River
(80202020102), Stouts Creek (80202020208), Turkey Creek-St. Francis
River (80202020210), and Wachita Creek-St. Francis River (80202020209).
The unit also consists of the entire St. Francis River upstream of
36.982104N, 90.335400W. The unit does not include any areas of adjacent
land. A large portion of the riparian land adjacent to streams in this
unit is privately owned (66 percent), with 32 percent in Federal
ownership and 2 percent in State ownership.

Effects of Critical Habitat Designation

Section 7 Consultation

Section 7(a)(2) of the Act requires Federal agencies, including the
Service, to ensure that any action they fund, authorize, or carry out
is not likely to jeopardize the continued existence of any endangered
species or threatened species or result in the destruction or adverse
modification of designated critical habitat of such species.

[[Page 25534]]

We published a final rule revising the definition of destruction or
adverse modification on August 27, 2019 (84 FR 44976). Destruction or
adverse modification means a direct or indirect alteration that
appreciably diminishes the value of critical habitat as a whole for the
conservation of a listed species.
If a Federal action may affect a listed species or its critical
habitat, the responsible Federal agency (action agency) must enter into
consultation with us. Examples of actions that are subject to the
section 7 consultation process are actions on State, Tribal, local, or
private lands that require a Federal permit (such as a permit from the
U.S. Army Corps of Engineers under section 404 of the Clean Water Act
or a permit from the Service under section 10 of the Act) or that
involve some other Federal action (such as funding from the Federal
Highway Administration, Federal Aviation Administration, or the Federal
Emergency Management Agency). Federal actions not affecting listed
species or critical habitat--and actions on State, Tribal, local, or
private lands that are not federally funded, authorized, or carried out
by a Federal agency--do not require section 7 consultation.
Compliance with the requirements of section 7(a)(2) is documented
through our issuance of:
(1) A concurrence letter for Federal actions that may affect, but
are not likely to adversely affect, listed species or critical habitat;
or
(2) A biological opinion for Federal actions that may affect, and
are likely to adversely affect, listed species or critical habitat.
When we issue a biological opinion concluding that a project is
likely to jeopardize the continued existence of a listed species and/or
destroy or adversely modify critical habitat, we provide reasonable and
prudent alternatives to the project, if any are identifiable, that
would avoid the likelihood of jeopardy and/or destruction or adverse
modification of critical habitat. We define ``reasonable and prudent
alternatives'' (at 50 CFR 402.02) as alternative actions identified
during consultation that:
(1) Can be implemented in a manner consistent with the intended
purpose of the action,
(2) Can be implemented consistent with the scope of the Federal
agency's legal authority and jurisdiction,
(3) Are economically and technologically feasible, and
(4) Would, in the Service Director's opinion, avoid the likelihood
of jeopardizing the continued existence of the listed species and/or
avoid the likelihood of destroying or adversely modifying critical
habitat.
Reasonable and prudent alternatives can vary from slight project
modifications to extensive redesign or relocation of the project. Costs
associated with implementing a reasonable and prudent alternative are
similarly variable.
Regulations at 50 CFR 402.16 set forth requirements for Federal
agencies to reinitiate consultation on previously reviewed actions.
These requirements apply when the Federal agency has retained
discretionary involvement or control over the action (or the agency's
discretionary involvement or control is authorized by law) and,
subsequent to the previous consultation: (a) if the amount or extent of
taking specified in the incidental take statement is exceeded; (b) if
new information reveals effects of the action that may affect listed
species or critical habitat in a manner or to an extent not previously
considered; (c) if the identified action is subsequently modified in a
manner that causes an effect to the listed species or critical habitat
that was not considered in the biological opinion or written
concurrence; or (d) if a new species is listed or critical habitat
designated that may be affected by the identified action. The
reinitiation requirement applies only to actions that remain subject to
some discretionary Federal involvement or control. As provided in 50
CFR 402.16, the requirement to reinitiate consultations for new species
listings or critical habitat designation does not apply to certain
agency actions (e.g., land management plans issued by the Bureau of
Land Management in certain circumstances.

Application of the ``Adverse Modification'' Standard

The key factor related to the destruction or adverse modification
determination is whether implementation of the proposed Federal action
directly or indirectly alters the designated critical habitat in a way
that appreciably diminishes the value of the critical habitat as a
whole for the conservation of the listed species. As discussed above,
the role of critical habitat is to support physical or biological
features essential to the conservation of a listed species and provide
for the conservation of the species.
Section 4(b)(8) of the Act requires us to briefly evaluate and
describe, in any proposed or final regulation that designates critical
habitat, activities involving a Federal action that may violate section
7(a)(2) of the Act by destroying or adversely modifying such habitat,
or that may be affected by such designation.
At this time, we are not aware of any activities that are likely to
destroy or adversely modify critical habitat. However, during each
consultation under section (7a)(2) of the Act, we will evaluate whether
proposed activities are likely to destroy or adversely modify critical
habitat.

Exemptions

Application of Section 4(a)(3) of the Act

Section 4(a)(3)(B)(i) of the Act (16 U.S.C. 1533(a)(3)(B)(i))
provides that the Secretary shall not designate as critical habitat any
lands or other geographical areas owned or controlled by the Department
of Defense (DoD), or designated for its use, that are subject to an
integrated natural resources management plan (INRMP) prepared under
section 101 of the Sikes Act Improvement Act of 1997 (16 U.S.C. 670a),
if the Secretary determines in writing that such plan provides a
benefit to the species for which critical habitat is proposed for
designation. There are no DoD lands with a completed INRMP within the
final critical habitat designations.

Consideration of Impacts Under Section 4(b)(2) of the Act

Section 4(b)(2) of the Act states that the Secretary shall
designate and make revisions to critical habitat on the basis of the
best available scientific data after taking into consideration the
economic impact, national security impact, and any other relevant
impact of specifying any particular area as critical habitat. The
Secretary may exclude an area from critical habitat if she determines
that the benefits of such exclusion outweigh the benefits of specifying
such area as part of the critical habitat, unless she determines, based
on the best scientific data available, that the failure to designate
such area as critical habitat will result in the extinction of the
species. In making the determination to exclude a particular area, the
statute on its face, as well as the legislative history, are clear that
the Secretary has broad discretion regarding which factor(s) to use and
how much weight to give to any factor. In this final rule, we have not
considered any areas for exclusion from critical habitat.
On December 18, 2020, we published a final rule in the Federal
Register (85 FR 82376) revising portions of our regulations pertaining
to exclusions of critical habitat. These final regulations became
effective on January 19, 2021, and apply to critical habitat rules for
which a proposed rule was published

[[Page 25535]]

after January 19, 2021. Consequently, these new regulations do not
apply to this final rule.

Exclusions Based on Economic Impacts

Section 4(b)(2) of the Act and its implementing regulations require
that we consider the economic impact that may result from a designation
of critical habitat. To consider economic impacts, we prepared an
incremental effects memorandum (IEM) and screening analysis, which,
together with our narrative and interpretation of effects, we consider
our economic analysis of the proposed critical habitat designations and
related factors (IEc 2019, entire). The analysis, dated March 28, 2019,
was made available for public review from September 17, 2020, through
November 16, 2020 (see 85 FR 58192; September 17, 2020) and from April
27, 2021, to May 27, 2021 (see 86 FR 22127; April 27, 2021). The
economic analysis addressed probable economic impacts of critical
habitat designation for Big Creek crayfish and St. Francis River
crayfish. Following the close of the comment periods, we reviewed and
evaluated all information submitted during the comment periods that may
pertain to our consideration of the probable incremental economic
impacts of these critical habitat designations.
Our analysis concluded that these costs will not reach the
threshold of ``significant'' under E.O. 12866. For the critical habitat
designations for both species, we anticipate a maximum of 115 section 7
consultations annually at a total incremental cost of approximately
$135,000 per year (IEc 2019, entire).
As we stated earlier, we solicited data and comments from the
public on the economic analysis, as well as all aspects of the proposed
rule and our required determinations. We did not receive any comments
or additional data that would necessitate a revision of our IEM or
screening analysis. Therefore, we are adopting our draft economic
analysis as our final economic analysis.
We considered the economic impacts of the critical habitat
designations. The Secretary is not exercising her discretion to exclude
any areas from these designations of critical habitat for the Big Creek
crayfish and the St. Francis River crayfish based on economic impacts.

Exclusions Based on Impacts on National Security and Homeland Security

In preparing this final rule, we have determined that the lands
within the designations of critical habitat for Big Creek crayfish and
St. Francis River crayfish are not owned or managed by the DoD or
Department of Homeland Security, and, therefore, we anticipate no
impact on national security or homeland security. We did not receive
any additional information during the public comment period for the
proposed designation regarding impacts of the designation on national
security or homeland security that would support excluding any specific
areas from the final critical habitat designation under authority of
section 4(b)(2) and our implementing regulations at 50 CFR 424.19.

Exclusions Based on Other Relevant Impacts

Under section 4(b)(2) of the Act, we consider any other relevant
impacts, in addition to economic impacts and impacts on national
security as discussed above. We consider a number of factors, including
whether there are permitted conservation plans covering the species in
the area such as HCPs, safe harbor agreements (SHAs), or candidate
conservation agreements with assurances (CCAAs), or whether there are
non-permitted conservation agreements and partnerships that would be
encouraged by designation of, or exclusion from, critical habitat. In
addition, we look at the existence of Tribal conservation plans and
partnerships and consider the government-to-government relationship of
the United States with Tribal entities. We also consider any social
impacts that might occur because of the designations.
In preparing this final rule, we have determined that there are
currently no HCPs or other management plans for Big Creek crayfish and
St. Francis River crayfish, and the designations do not include any
Tribal lands or trust resources. We anticipate no impact on Tribal
lands, partnerships, or HCPs from the critical habitat designations.
Additionally, as described above, we are not excluding any particular
areas on the basis of impacts to national security or economic impacts
because there are no national security areas in the critical habitat
designations.
During the development of these final designations, we considered
all additional information received through the public comment periods
regarding other relevant impacts to determine whether any specific
areas should have been excluded from the final critical habitat
designations under authority of section 4(b)(2) and our implementing
regulations at 50 CFR 424.19. As stated above, the Secretary is not
exercising her discretion to exclude any areas from the final critical
habitat designations.

Required Determinations

Regulatory Planning and Review (Executive Orders 12866 and 13563)

Executive Order 12866 provides that the Office of Information and
Regulatory Affairs (OIRA) in the Office of Management and Budget will
review all significant rules. OIRA has determined that this rule is not
significant.
Executive Order 13563 reaffirms the principles of E.O. 12866 while
calling for improvements in the nation's regulatory system to promote
predictability, to reduce uncertainty, and to use the best, most
innovative, and least burdensome tools for achieving regulatory ends.
The executive order directs agencies to consider regulatory approaches
that reduce burdens and maintain flexibility and freedom of choice for
the public where these approaches are relevant, feasible, and
consistent with regulatory objectives. E.O. 13563 emphasizes further
that regulations must be based on the best available science and that
the rulemaking process must allow for public participation and an open
exchange of ideas. We have developed this final rule in a manner
consistent with these requirements.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.),
as amended by the Small Business Regulatory Enforcement Fairness Act of
1996 (SBREFA; 5 U.S.C. 801 et seq.), whenever an agency is required to
publish a notice of rulemaking for any proposed or final rule, it must
prepare and make available for public comment a regulatory flexibility
analysis that describes the effects of the rule on small entities
(i.e., small businesses, small organizations, and small government
jurisdictions). However, no regulatory flexibility analysis is required
if the head of the agency certifies the rule will not have a
significant economic impact on a substantial number of small entities.
The SBREFA amended the RFA to require Federal agencies to provide a
certification statement of the factual basis for certifying that the
rule will not have a significant economic impact on a substantial
number of small entities.
According to the Small Business Administration, small entities
include small organizations such as independent nonprofit
organizations; small governmental jurisdictions, including school
boards and city and town governments that serve fewer than 50,000
residents; and small businesses (13 CFR 121.201). Small businesses
include manufacturing and mining

[[Page 25536]]

concerns with fewer than 500 employees, wholesale trade entities with
fewer than 100 employees, retail and service businesses with less than
$5 million in annual sales, general and heavy construction businesses
with less than $27.5 million in annual business, special trade
contractors doing less than $11.5 million in annual business, and
agricultural businesses with annual sales less than $750,000. To
determine if potential economic impacts to these small entities are
significant, we considered the types of activities that might trigger
regulatory impacts under this designation as well as types of project
modifications that may result. In general, the term ``significant
economic impact'' is meant to apply to a typical small business firm's
business operations.
Under the RFA, as amended, and as understood in light of recent
court decisions, Federal agencies are required to evaluate the
potential incremental impacts of rulemaking on those entities directly
regulated by the rulemaking itself; in other words, the RFA does not
require agencies to evaluate the potential impacts to indirectly
regulated entities. The regulatory mechanism through which critical
habitat protections are realized is section 7 of the Act, which
requires Federal agencies, in consultation with the Service, to ensure
that any action authorized, funded, or carried out by the agency is not
likely to destroy or adversely modify critical habitat. Therefore,
under section 7, only Federal action agencies are directly subject to
the specific regulatory requirement (avoiding destruction and adverse
modification) imposed by critical habitat designation. Consequently, it
is our position that only Federal action agencies will be directly
regulated by this designation. There is no requirement under the RFA to
evaluate the potential impacts to entities not directly regulated.
Moreover, Federal agencies are not small entities. Therefore, because
no small entities will be directly regulated by this rulemaking, we
certify that the final critical habitat designations will not have a
significant economic impact on a substantial number of small entities.
In summary, we have considered whether the final critical habitat
designations will result in a significant economic impact on a
substantial number of small entities. For the above reasons and based
on currently available information, we certify that the final critical
habitat designation will not have a significant economic impact on a
substantial number of small business entities. Therefore, a regulatory
flexibility analysis is not required.

Energy Supply, Distribution, or Use--Executive Order 13211

Executive Order 13211 (Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use) requires
agencies to prepare Statements of Energy Effects when undertaking
certain actions. In our economic analysis, we did not find that the
critical habitat designations will significantly affect energy
supplies, distribution, or use. The critical habitat designations for
Big Creek crayfish and St. Francis River crayfish are unlikely to
generate costs exceeding $100 million in a single year (IEc 2019, p.
2). Therefore, this action is not a significant energy action, and no
Statement of Energy Effects is required.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501
et seq.), we make the following finding:
(1) This rule will not produce a Federal mandate. In general, a
Federal mandate is a provision in legislation, statute, or regulation
that would impose an enforceable duty upon State, local, or Tribal
governments, or the private sector, and includes both ``Federal
intergovernmental mandates'' and ``Federal private sector mandates.''
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal
intergovernmental mandate'' includes a regulation that ``would impose
an enforceable duty upon State, local, or Tribal governments'' with two
exceptions. It excludes ``a condition of Federal assistance.'' It also
excludes ``a duty arising from participation in a voluntary Federal
program,'' unless the regulation ``relates to a then-existing Federal
program under which $500,000,000 or more is provided annually to State,
local, and Tribal governments under entitlement authority,'' if the
provision would ``increase the stringency of conditions of assistance''
or ``place caps upon, or otherwise decrease, the Federal Government's
responsibility to provide funding,'' and the State, local, or Tribal
governments ``lack authority'' to adjust accordingly. At the time of
enactment, these entitlement programs were: Medicaid; Aid to Families
with Dependent Children work programs; Child Nutrition; Food Stamps;
Social Services Block Grants; Vocational Rehabilitation State Grants;
Foster Care, Adoption Assistance, and Independent Living; Family
Support Welfare Services; and Child Support Enforcement. ``Federal
private sector mandate'' includes a regulation that ``would impose an
enforceable duty upon the private sector, except (i) a condition of
Federal assistance or (ii) a duty arising from participation in a
voluntary Federal program.''
The designation of critical habitat does not impose a legally
binding duty on non-Federal Government entities or private parties.
Under the Act, the only regulatory effect is that Federal agencies must
ensure that their actions do not destroy or adversely modify critical
habitat under section 7. While non-Federal entities that receive
Federal funding, assistance, or permits, or that otherwise require
approval or authorization from a Federal agency for an action, may be
indirectly impacted by the designation of critical habitat, the legally
binding duty to avoid destruction or adverse modification of critical
habitat rests squarely on the Federal agency. Furthermore, to the
extent that non-Federal entities are indirectly impacted because they
receive Federal assistance or participate in a voluntary Federal aid
program, the Unfunded Mandates Reform Act would not apply, nor would
critical habitat shift the costs of the large entitlement programs
listed above onto State governments.
(2) We do not believe that this rule will significantly or uniquely
affect small governments because the lands within the critical habitat
designations are primarily Federally or privately owned and are managed
by the State of Missouri and, therefore, do not fall within the
jurisdiction of small governments. Therefore, a Small Government Agency
Plan is not required.

Takings--Executive Order 12630

In accordance with E.O. 12630 (Government Actions and Interference
with Constitutionally Protected Private Property Rights), we have
analyzed the potential takings implications of designating critical
habitat for Big Creek crayfish and St. Francis River crayfish in a
takings implications assessment. The Act does not authorize the Service
to regulate private actions on private lands or confiscate private
property as a result of critical habitat designation. Designation of
critical habitat does not affect land ownership, or establish any
closures, or restrictions on use of or access to the designated areas.
Furthermore, the designation of critical habitat does not affect
landowner actions that do not require Federal funding or permits, nor
does it preclude development of habitat conservation programs or
issuance of incidental take permits to permit actions that do require

[[Page 25537]]

Federal funding or permits to go forward. However, Federal agencies are
prohibited from carrying out, funding, or authorizing actions that
would destroy or adversely modify critical habitat. A takings
implications assessment has been completed for the designation of
critical habitat for Big Creek crayfish and the St. Francis River
crayfish, and it concludes that the designations of critical habitat do
not pose significant takings implications for lands within or affected
by the designations.

Federalism--Executive Order 13132

In accordance with E.O. 13132 (Federalism), this rule does not have
significant Federalism effects. A federalism summary impact statement
is not required. In keeping with Department of the Interior and
Department of Commerce policy, we requested information from, and
coordinated development of the critical habitat designations with,
appropriate State resource agencies and incorporated comments when
applicable into this final rule. From a federalism perspective, the
designation of critical habitat directly affects only the
responsibilities of Federal agencies. The Act imposes no other duties
with respect to critical habitat, either for States and local
governments, or for anyone else. As a result, the rule does not have
substantial direct effects either on the States, or on the relationship
between the national government and the States, or on the distribution
of powers and responsibilities among the various levels of government.
The designations may have some benefit to these governments because the
areas that contain the features essential to the conservation of the
species are more clearly defined, and the physical or biological
features of the habitat necessary for the conservation of the species
are specifically identified. This information does not alter where and
what federally sponsored activities may occur. However, it may assist
State and local governments in long-range planning because they no
longer have to wait for case-by-case section 7 consultations to occur.
Where State and local governments require approval or authorization
from a Federal agency for actions that may affect critical habitat,
consultation under section 7(a)(2) of the Act will be required. While
non-Federal entities that receive Federal funding, assistance, or
permits, or that otherwise require approval or authorization from a
Federal agency for an action, may be indirectly impacted by the
designation of critical habitat, the legally binding duty to avoid
destruction or adverse modification of critical habitat rests squarely
on the Federal agency.

Civil Justice Reform--Executive Order 12988

In accordance with Executive Order 12988 (Civil Justice Reform),
the Office of the Solicitor has determined that the rule will not
unduly burden the judicial system and that it meets the requirements of
sections 3(a) and 3(b)(2) of the Order. We are designating critical
habitat in accordance with the provisions of the Act. To assist the
public in understanding the habitat needs of the species, this rule
identifies the physical or biological features essential to the
conservation of the species. The designated areas of critical habitat
are presented on maps, and the rule provides several options for the
interested public to obtain more detailed location information, if
desired.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

This rule does not contain information collection requirements, and
a submission to the Office of Management and Budget (OMB) under the
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.) is not
required. We may not conduct or sponsor and you are not required to
respond to a collection of information unless it displays a currently
valid OMB control number.

National Environmental Policy Act (32 U.S.C. 4321 et seq.)

Regulations adopted pursuant to section 4(a) of the Act are exempt
from the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et
seq.) and do not require an environmental analysis under NEPA. We
published a notice outlining our reasons for this determination in the
Federal Register on October 25, 1983 (48 FR 49244). This includes
listing, delisting, and reclassification rules, as well as critical
habitat designations and species-specific protective regulations
promulgated concurrently with a decision to list or reclassify a
species as threatened. The courts have upheld this position (e.g.,
Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995) (critical
habitat); Center for Biological Diversity v. U.S. Fish and Wildlife
Service, 2005 WL 2000928 (N.D. Cal. Aug. 19, 2005) (concurrent 4(d)
rule)).

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 federally recognized
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
Tribes in developing programs for healthy ecosystems, to acknowledge
that Tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to Tribes. We have determined that no Tribal
lands fall within the boundaries of the final critical habitat
designation for the Big Creek crayfish or for the St. Francis River
crayfish, so no Tribal lands will be affected by the designations.

References Cited

A complete list of references cited in this rulemaking is available
on the internet at https://www.regulations.gov and upon request from
the Missouri Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).

Authors

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

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

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

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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

0
2. Amend Sec. 17.11, in paragraph (h), by adding, in alphabetical
order under CRUSTACEANS, entries for ``Crayfish, Big Creek'' and
``Crayfish, St. Francis

[[Page 25538]]

River'' to the List of Endangered and Threatened Wildlife to read as
follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *
(h) * * *

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

* * * * * * *
Crustaceans

* * * * * * *
Crayfish, Big Creek............. Faxonius peruncus.. Wherever found.... T 88 FR [insert Federal
Register page where
the document begins],
4/27/2023; 50 CFR
17.46(c);\4d\ 50 CFR
17.95(h).\CH\

* * * * * * *
Crayfish, St. Francis River..... Faxonius quadruncus Wherever found.... T 88 FR [insert Federal
Register page where
the document begins],
4/27/2023; 50 CFR
17.46(c);\4d\ 50 CFR
17.95(h).\CH\

* * * * * * *
----------------------------------------------------------------------------------------------------------------

0
3. Amend Sec. 17.46 by adding paragraph (c) to read as follows:

Sec. 17.46 Special rules--crustaceans.

* * * * *
(c) Big Creek crayfish (Faxonius peruncus) and St. Francis River
crayfish (Faxonius quadruncus).
(1) Prohibitions. The following prohibitions that apply to
endangered wildlife also apply to the Big Creek crayfish and the St.
Francis River crayfish. Except as provided under paragraph (c)(2) of
this section and Sec. Sec. 17.4 and 17.5, it is unlawful for any
person subject to the jurisdiction of the United States to commit, to
attempt to commit, to solicit another to commit, or cause to be
committed, any of the following acts in regard to this species:
(i) Import or export, as set forth at Sec. 17.21(b) for endangered
wildlife.
(ii) Take, as set forth at Sec. 17.21(c)(1) for endangered
wildlife. Activities that could result in take are those that:
(A) Impact crayfish habitat, riparian areas adjacent to crayfish
sites, or habitat between connecting sites such that the species'
reproduction or survival will be impacted or the effects of woodland
crayfish invasion will be exacerbated. Such activities include, but are
not limited to:
(1) Construction of instream low-water crossings;
(2) Destruction of riparian habitat that results in excessive
sedimentation;
(3) Bridge construction; and
(4) Gravel mining.
(B) Lead to the introduction of heavy metals into streams. Such
activities include, but are not limited to, heavy metal mining.
(C) Appreciably negatively affect water quality, chemistry, or
quantity such that the species' reproduction or survival will be
impacted. Such activities may include, but are not limited to, the
release of wastewater effluent and agricultural runoff.
(D) Impact hydrological flows such that the species' reproduction
or survival will be impacted. Such activities include, but are not
limited to, construction of dams, modification of stream channels, and
surface and groundwater withdrawals.
(E) Facilitate the spread of woodland crayfish or introduce
additional woodland crayfish in occupied Big Creek crayfish or St.
Francis River crayfish stream reaches. Such activities may include, but
are not limited to, bait bucket dumping.
(iii) Possession and other acts with unlawfully taken specimens, as
set forth at Sec. 17.21(d)(1) for endangered wildlife.
(iv) Interstate or foreign commerce in the course of commercial
activity, as set forth at Sec. 17.21(e) for endangered wildlife.
(v) Sale or offer for sale, as set forth at Sec. 17.21(f) for
endangered wildlife.
(2) Exceptions from prohibitions. In regard to this species, you
may:
(i) Conduct activities as authorized by a permit under Sec. 17.32.
(ii) Take, as set forth at Sec. 17.21(c)(2) through (c)(4) for
endangered wildlife.
(iii) Take, as set forth at Sec. 17.31(b).
(iv) Take incidental to an otherwise lawful activity caused by:
(A) Restoration activities or other activities that will result in
an overall benefit to one or both of the species or their habitat that
are completed in coordination with the Missouri Ecological Services
Field Office. Such activities include, but are not limited to, stream
bank stabilization, habitat restoration, heavy metal remediation, and
replacement of low water crossings that obstruct movement of aquatic
organisms with crossings that facilitate the movement of aquatic
species (aquatic organism passages).
(B) A person conducting research or education under a valid
Missouri Department of Conservation Wildlife Collector's permit.
(v) Possess and engage in other acts with unlawfully taken
wildlife, as set forth at Sec. 17.21(d)(2) for endangered wildlife.

0
4. In Sec. 17.95 amend paragraph (h), by:
0
a. Adding an entry for ``Big Creek Crayfish (Faxonius peruncus)''
following the entry for ``Pecos amphipod (Gammarus pecos)''; and
0
b. Adding an entry for ``St. Francis River Crayfish (Faxonius
quadruncus)'' following the entry for ``Slenderclaw Crayfish (Cambarus
cracens)''.
The additions read as follows:

Sec. 17.95 Critical habitat--fish and wildlife.

* * * * *
(h) Crustaceans.
* * * * *
Big Creek Crayfish (Faxonius peruncus)
(1) The critical habitat unit is depicted for Iron, Madison, St.
Francois, Washington, and Wayne Counties in Missouri, on the map in
this entry.
(2) Within the critical habitat unit, the physical or biological
features essential to the conservation of the Big Creek crayfish
consist of the following components:
(i) Stream flow velocity generally between 0 and 1.1 feet per
second (ft/s) (0 and 0.35 meters per second (m/s)).
(ii) Stream depths generally between 0.2 and 1.6 feet (0.06 and
0.49 meters).
(iii) Water temperatures between 34 and 84 [deg]F (1.1 and 28.9
[deg]C).
(iv) Adequately low stream embeddedness so that spaces under rocks
and cavities in gravel remain available to the Big Creek crayfish.

[[Page 25539]]

(v) An available forage and prey base consisting of invertebrates,
periphyton, and plant detritus.
(vi) Connectivity among occupied stream reaches of the Big Creek
crayfish (both within and among occupied subwatersheds).
(vii) Adequately low ratios or densities of nonnative species that
allow for maintaining populations of the Big Creek crayfish.
(3) Critical habitat does not include manmade structures (such as
buildings, aqueducts, runways, roads, and other paved areas) and the
land on which they are located existing within the legal boundaries on
May 30, 2023.
(4) The National Hydrography Dataset Plus (NHDPlus) was the
geospatial data used to delineate critical habitat. NHDPlus is a
national geospatial surface water framework that integrates the
National Hydrography Dataset with the National Elevation Dataset and
the Watershed Boundary Dataset. NHDPlus uses medium resolution
(1:100,000-scale) data with a geographic projection and NAD83 datum.
Critical habitat was delineated by including all streams within
subwatersheds (at the 12-digit hydrologic unit level) occupied by the
Big Creek crayfish. Occupied watersheds were defined using data from
the Missouri Department of Conservation; the entire St. Francis River
upstream of 37.091254N, 90.447212W is also considered occupied as a
migratory route. The map in this entry, as modified by any accompanying
regulatory text, establishes the boundaries of the critical habitat
designation. The coordinates or plot points or both on which the map is
based are available to the public at https://www.regulations.gov under
Docket No. FWS-R3-ES-2019-0020 and at the Missouri Ecological Services
Field Office. You may obtain field office location information by
contacting one of the Service regional offices, the addresses of which
are listed at 50 CFR 2.2.
(5) Big Creek Crayfish Unit--Iron, Madison, St. Francois,
Washington, and Wayne Counties, Missouri.
(i) The unit consists of all of the streams (approximately 1,069
river miles (1,720 kilometers)) upstream of Wappapello Dam in the
following subwatersheds (numbers in parentheses represent the 12-digit
hydrologic codes): Big Lake Creek-St. Francis River (080202020503),
Blankshire Branch-St. Francis River (080202020204), Captain Creek-St.
Francis River (080202020405), Cedar Bottom Creek-St. Francis River
(080202020402), Clark Creek (080202020407), Cedar Bottom Creek
(080202020501), Crane Pond Creek (080202020303), Headwaters St. Francis
River (080202020201), Headwaters Twelvemile Creek (080202020403),
Leatherwood Creek-St. Francis River (080202020406), Lower Big Creek
(080202020304), Middle Big Creek (080202020302), Saline Creek-Little
St. Francis River (080202020102), Turkey Creek-St. Francis River
(080202020210), Twelvemile Creek (080202020404), and Upper Big Creek
(080202020301). The unit also consists of the entire St. Francis River
upstream of 37.091254N, 90.447212W. The unit does not include any areas
of adjacent land. This unit includes stream habitat up to bank full
height.
(ii) Map of Big Creek Crayfish Unit of Big Creek crayfish critical
habitat follows:

BILLING CODE 4333-15-P
Figure 1 for Big Creek Crayfish (Faxonius peruncus) paragraph (5)(ii)

[[Page 25540]]

[GRAPHIC] [TIFF OMITTED] TR27AP23.152

* * * * *
BILLING CODE 4333-15-C
St. Francis River Crayfish (Faxonius quadruncus)
(1) The critical habitat unit is depicted for Iron, Madison, St.
Francois, Washington, and Wayne Counties in Missouri, on the map in
this entry.
(2) Within the critical habitat unit, the physical or biological
features essential to the conservation of the St. Francis River
crayfish consist of the following components:
(i) Stream flow velocity generally between 0 and 1.1 feet per
second (ft/s) (0 and 0.35 meters per second (m/s)).
(ii) Stream depths generally between 0.2 and 1.7 feet (0.06 and
0.52 meters).
(iii) Water temperatures between 34 and 84 [deg]F (1.1 and 28.9
[deg]C).
(iv) Adequately low stream embeddedness so that spaces under rocks
and cavities in gravel remain available to the St. Francis River
crayfish.
(v) An available forage and prey base consisting of invertebrates,
periphyton, and plant detritus.
(vi) Connectivity among occupied stream reaches of the St. Francis
River

[[Page 25541]]

crayfish (both within and among occupied subwatersheds).
(vii) Adequately low ratios or densities of nonnative species that
allow for maintaining populations of the St. Francis River crayfish.
(3) Critical habitat does not include manmade structures (such as
buildings, aqueducts, runways, roads, and other paved areas) and the
land on which they are located existing within the legal boundaries on
May 30, 2023.
(4) The National Hydrography Dataset Plus (NHDPlus) was the
geospatial data used to delineate critical habitat. NHDPlus is a
national geospatial surface water framework that integrates the
National Hydrography Dataset with the National Elevation Dataset and
the Watershed Boundary Dataset. NHDPlus uses medium resolution
(1:100,000-scale) data with a geographic projection and NAD83 Datum.
Critical habitat was delineated by including all streams within
subwatersheds (at the 12-digit hydrologic unit level) occupied by the
St. Francis River crayfish. Occupied watersheds were defined using data
from the Missouri Department of Conservation; the entire St. Francis
River upstream of 36.982104N, 90.335400W is also considered occupied as
a migratory route. The map in this entry, as modified by any
accompanying regulatory text, establishes the boundaries of the
critical habitat designation. The coordinates or plot points or both on
which the map is based are available to the public at https://www.regulations.gov under Docket No. FWS-R3-ES-2019-0020 and at the
Missouri Ecological Services Field Office. You may obtain field office
location information by contacting one of the Service regional offices,
the addresses of which are listed at 50 CFR 2.2.
(5) St. Francis River Crayfish Unit--Iron, Madison, St. Francois,
Washington, and Wayne Counties, Missouri.
(i) The unit consists of all of the streams (approximately 1,043
river miles (1,679 kilometers)) upstream of Wappapello Dam in the
following subwatersheds (numbers in parentheses represent the 12-digit
hydrologic codes): Blankshire Branch-St. Francis River (80202020204),
Captain Creek-St. Francis River (80202020405), Cedar Bottom Creek-St.
Francis River (80202020402), Headwaters St. Francis River
(80202020201), Headwaters Stouts Creek (80202020207), Hubble Creek-St.
Francis River (80202020502), Leatherwood Creek-St. Francis River
(80202020406), Little St. Francis River (80202020103), Lost Creek
(80202020507), Marble Creek (80202020401), Musco Creek-Little St.
Francis River (80202020101), O'Bannon Creek-St. Francis River
(80202020206), Saline Creek-Little St. Francis River (80202020102),
Stouts Creek (80202020208), Turkey Creek-St. Francis River
(80202020210), and Wachita Creek-St. Francis River (80202020209). The
unit also consists of the entire St. Francis River upstream of
36.982104N, 90.335400W. The unit does not include any areas of adjacent
land. The Upper St. Francis River Watershed Unit includes stream
habitat up to bank full height.
(ii) Map of St. Francis River Crayfish Unit of St. Francis River
crayfish critical habitat follows:
BILLING CODE 4333-15-P
Figure 1 for St. Francis River Crayfish (Faxonius quadruncus) paragraph
(5)(ii)

[[Page 25542]]

[GRAPHIC] [TIFF OMITTED] TR27AP23.153

* * * * *

Wendi Weber,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2023-08849 Filed 4-26-23; 8:45 am]
BILLING CODE 4333-15-C