[Federal Register Volume 88, Number 181 (Wednesday, September 20, 2023)]
[Proposed Rules]
[Pages 64856-64870]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-20293]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2023-0103; FF09E21000 FXES1111090FEDR 234]
RIN 1018-BG31


Endangered and Threatened Wildlife and Plants; Threatened Species 
Status With Section 4(d) Rule for the Miami Cave Crayfish

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the Miami cave crayfish (Procambarus milleri), a crayfish species 
from Miami-Dade County, Florida, as a threatened species under the 
Endangered Species Act of 1973, as amended (Act). This determination 
also serves as our 12-month finding on a petition to list the Miami 
cave crayfish. After a review of the best available scientific and 
commercial information, we find that listing the species is warranted. 
Accordingly, we propose to list the Miami cave crayfish as a threatened 
species with a rule issued under section 4(d) of the Act (``4(d) 
rule''). If we finalize this proposed rule, it would add this species 
to the List of Endangered and Threatened Wildlife and extend the Act's 
protections to the species.

DATES: We will accept comments received or postmarked on or before 
November 20, 2023. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59 
p.m. eastern time on the closing date. We must receive requests for a 
public hearing, in writing, at the address shown in FOR FURTHER 
INFORMATION CONTACT by November 6, 2023.

ADDRESSES: You may submit comments by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: https://www.regulations.gov. In the Search box, enter FWS-R4-ES-2023-0103, 
which is the docket number for this rulemaking. Then, click on the 
Search button. On the resulting page, in the panel on the left side of 
the screen, under the Document Type heading, check the Proposed Rule 
box to locate this document. You may submit a comment by clicking on 
``Comment.''
    (2) By hard copy: Submit by U.S. mail to: Public Comments 
Processing, Attn: FWS-R4-ES-2023-0103, U.S. Fish and Wildlife Service, 
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
    We request that you send comments only by the methods described 
above. We will post all comments on https://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see Information Requested, below, for more information).
    Availability of supporting materials: Supporting materials, such as 
the species status assessment report, are available at https://www.regulations.gov at Docket No. FWS-R4-ES-2023-0103.

FOR FURTHER INFORMATION CONTACT: Lourdes Mena, Division Manager, 
Florida Classification and Recovery, U.S. Fish and Wildlife Service, 
Florida Ecological Services Field Office, 7915 Baymeadows Way, Suite 
200, Jacksonville, FL 32256-7517; telephone 904-731-3134. Individuals 
in the United States who are deaf, deafblind, hard of hearing, or have 
a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access 
telecommunications relay services. Individuals outside the United 
States should use the relay services offered within their country to 
make international calls to the point-of-contact in the United States. 
For a summary of the proposed rule, please see the ``rule summary 
document'' in docket FWS-R4-ES-2023-0103 on https://www.regulations.gov.

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 an endangered species 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 
Miami cave crayfish meets the definition of a threatened species; 
therefore, we are proposing to list it as such. Listing a species as an 
endangered or threatened species can be completed only by issuing a 
rule through the Administrative Procedure Act rulemaking process (5 
U.S.C. 551 et seq.).
    What this document does. We propose to list the Miami cave crayfish 
as a threatened species with a rule under section 4(d) of the Act.
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that the primary threat to 
Miami cave crayfish is saltwater intrusion caused by sea level rise as 
a result of climate change.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other governmental agencies, Native 
American Tribes, the

[[Page 64857]]

scientific community, industry, or any other interested parties 
concerning this proposed rule. We particularly seek comments 
concerning:
    (1) The species' biology, range, and population trends, including:
    (a) Biological or ecological requirements of the species, including 
habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns 
and the locations of any additional populations of this species;
    (d) Historical and current population levels, and current and 
projected trends; and
    (e) Past and ongoing conservation measures for the species, its 
habitat, or both.
    (2) Threats and conservation actions affecting the species, 
including:
    (a) Factors that may be affecting the continued existence of the 
species, which may include habitat modification or destruction, 
overutilization, disease, predation, the inadequacy of existing 
regulatory mechanisms, or other natural or manmade factors.
    (b) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to this species.
    (c) Existing regulations or conservation actions that may be 
addressing threats to this species.
    (3) Additional information concerning the historical and current 
status of this species.
    (4) Information on regulations that may be necessary and advisable 
to provide for the conservation of the Miami cave crayfish and that we 
can consider in developing a 4(d) rule for the species. In particular, 
information concerning the extent to which we should include any of the 
section 9 prohibitions in the 4(d) rule or whether we should consider 
any additional exceptions from the prohibitions in the 4(d) rule.
    (5) Information on sea level rise and saltwater intrusion future 
projections in the Biscayne Aquifer.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Please note that submissions merely stating support for, or 
opposition to, the action under consideration without providing 
supporting information, although noted, do not provide substantial 
information necessary to support a determination. Section 4(b)(1)(A) of 
the Act directs that determinations as to whether any species is an 
endangered or a threatened species must be made solely on the basis of 
the best scientific and commercial data available.
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the website. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on https://www.regulations.gov.
    Our final determination may differ from this proposal because we 
will consider all comments we receive during the comment period as well 
as any information that may become available after this proposal. Based 
on the new information we receive (and, if relevant, any comments on 
that new information), we may conclude that the species is endangered 
instead of threatened, or we may conclude that the species does not 
warrant listing as either an endangered species or a threatened 
species. In addition, we may change the parameters of the prohibitions 
or the exceptions to those prohibitions in the 4(d) rule if we conclude 
it is appropriate in light of comments and new information received. 
For example, we may expand the prohibitions to include prohibiting 
additional activities if we conclude that those additional activities 
are not compatible with conservation of the species. Conversely, we may 
establish additional exceptions to the prohibitions in the final rule 
if we conclude that the activities would facilitate or are compatible 
with the conservation and recovery of the species. In our final rule, 
we will clearly explain our rationale and the basis for our final 
decision, including why we made changes, if any, that differ from this 
proposal.

Public Hearing

    Section 4(b)(5) of the Act provides for a public hearing on this 
proposal, if requested. Requests must be received by the date specified 
in DATES. Such requests must be sent to the address shown in FOR 
FURTHER INFORMATION CONTACT. We will schedule a public hearing on this 
proposal, if requested, and announce the date, time, and place of the 
hearing, as well as how to obtain reasonable accommodations, in the 
Federal Register and local newspapers at least 15 days before the 
hearing. We may hold the public hearing in person or virtually via 
webinar. We will announce any public hearing on our website, in 
addition to the Federal Register. The use of virtual public hearings is 
consistent with our regulations at 50 CFR 424.16(c)(3).

Previous Federal Actions

    We received a petition from the Center for Biological Diversity, 
Alabama Rivers Alliance, Clinch Coalition, Dogwood Alliance, Gulf 
Restoration Network, Tennessee Forests Council, West Virginia Highlands 
Conservancy, Tierra Curry, and Noah Greenwald on April 20, 2010, to 
list 404 aquatic, riparian, and wetland species from the southeastern 
United States as threatened or endangered species and to designate 
critical habitat under the Endangered Species Act (Act). The Miami cave 
crayfish was included in this petition. On September 27, 2011, we 
published a 90-day finding in the Federal Register (76 FR 59836), 
concluding that the petition presented substantial information that 
indicated listing the Miami cave crayfish may be warranted. This 
document serves as both our 12-month warranted petition finding and our 
proposed rule to list this species.

Peer Review

    A species status assessment (SSA) team prepared an SSA report for 
the Miami cave 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 Miami cave crayfish SSA 
report. We sent the SSA report to four independent peer reviewers and 
received three responses. Results of this structured peer review 
process can be found at https://regulations.gov. In preparing this 
proposed rule, we incorporated the results of these reviews, as 
appropriate,

[[Page 64858]]

into the SSA report, which is the foundation for this proposed rule.

Summary of Peer Reviewer Comments

    As discussed in Peer Review above, we received comments from three 
peer reviewers on the draft SSA report. We reviewed all comments we 
received from the peer reviewers for substantive issues and new 
information regarding the contents of the SSA report. The peer 
reviewers generally concurred with our methods and conclusions and 
provided additional information, clarifications, and suggestions, 
including clarification on our methodology used to determine the 
quantity of habitat and other editorial suggestions. Two peer reviewers 
provided additional locations of Miami cave crayfish within the 
established range of the species that we incorporated into the SSA 
report. Otherwise, no substantive changes to our analysis and 
conclusions within the SSA report were deemed necessary, and peer 
reviewer comments are addressed in version 1.0 of the SSA report.

I. Proposed Listing Determination

Background

    A thorough review of the taxonomy, life history, and ecology of the 
Miami cave crayfish (Procambarus milleri) is presented in the SSA 
report (version 1.1; Service 2022, pp. 3-18).
    The Miami cave crayfish is a relatively small, freshwater, 
subterranean crayfish endemic to southern and central Miami-Dade 
County, Florida. On an evolutionary timescale, the Miami cave crayfish 
is recently adapted to the belowground aquifer environment as is 
indicated by the presence of both pigment and eye facets in some 
individuals. Miami cave crayfish are opportunistic omnivores, primarily 
consuming surficial detritus that filters down through the porous 
limestone into their aquifer habitat (Radice and Loftus 1995, p. 114). 
Individuals may also consume amphipods and isopods found in the same 
habitat (Hobbs 1971, p. 114).
    The species was first described based on specimens collected from a 
22-foot (ft; 6.7-meter (m)) deep well, south of Miami in 1968 (Hobbs 
1971, entire). Additional confirmed reports of the species followed in 
1992, 2000-2004, 2009, and most recently in 2018. The species has been 
collected from wells 7.9-36 ft (2.41-11 m) deep in the Miami Limestone 
and Fort Thompson Formation within the Biscayne Aquifer along the 
Atlantic Coastal Ridge.
    The Atlantic Coastal Ridge is a northeast-to-southwest-trending 
elevated feature, varying between 1.8-10 miles (mi) (3-16 kilometers 
(km)) in width and rising 3.2-28.2 ft (1-8.6 m) above sea level between 
Everglades National Park, Homestead, and North Miami (Fish and Stewart 
1991, p. 4; Wacker et al. 2014, p. 26; Whitman and Yeboah-Forson 2015, 
pp. 782, 790; Meeder and Harlem 2019, pp. 560-561). The Miami Limestone 
and Fort Thompson Formation on the Atlantic Coastal Ridge are highly 
porous (containing large holes and cavities), resembling a sponge, 
whereas those same geologic layers in the surrounding area are partly 
or completely cemented with mud and sand. The Miami cave crayfish is 
adapted to the unique porosity of the Atlantic Coastal Ridge, which 
provides nutrient flow and subterranean space to inhabit. Miami cave 
crayfish likely occupy the Biscayne Aquifer from the top of the water 
table in the Miami Limestone to the bottom of the Fort Thompson 
Formation. The species has not been observed outside of the Atlantic 
Coastal Ridge, despite surveys done in the surrounding area.

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;
    (B) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (C) Disease or predation;
    (D) The inadequacy of existing regulatory mechanisms; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the species' expected response and 
the effects of the threats--in light of those actions and conditions 
that will ameliorate the threats--on an individual, population, and 
species level. We evaluate each threat and its expected effects on the 
species, then analyze the cumulative effect of all of the threats on 
the species as a whole. We also consider the cumulative effect of the 
threats in light of those actions and conditions that will have 
positive effects on the species, such as any existing regulatory 
mechanisms or conservation efforts. The Secretary determines whether 
the species meets the definition of an ``endangered species'' or a 
``threatened species'' only after conducting this cumulative analysis 
and describing the expected effect on the species now and in the 
foreseeable future.

[[Page 64859]]

    The Act does not define the term ``foreseeable future,'' which 
appears in the statutory definition of ``threatened species.'' Our 
implementing regulations at 50 CFR 424.11(d) set forth a framework for 
evaluating the foreseeable future on a case-by-case basis. The term 
``foreseeable future'' extends only so far into the future as we can 
reasonably determine that both the future threats and the species' 
responses to those threats are likely. In other words, the foreseeable 
future is the period of time in which we can make reliable predictions. 
``Reliable'' does not mean ``certain''; it means sufficient to provide 
a reasonable degree of confidence in the prediction. Thus, a prediction 
is reliable if it is reasonable to depend on it when making decisions.
    It is not always possible or necessary to define the foreseeable 
future as a particular number of years. Analysis of the foreseeable 
future uses the best scientific and commercial data available and 
should consider the timeframes applicable to the relevant threats and 
to the species' likely responses to those threats in view of its life-
history characteristics. Data that are typically relevant to assessing 
the species' biological response include species-specific factors such 
as lifespan, reproductive rates or productivity, certain behaviors, and 
other demographic factors.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological review of the best scientific and commercial data regarding 
the status of the species, including an assessment of the potential 
threats to the species. The SSA report does not represent our decision 
on whether the species should be proposed for listing 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 Miami cave crayfish viability, we used the three 
conservation biology principles of resiliency, redundancy, and 
representation (Shaffer and Stein 2000, pp. 306-310). Briefly, 
resiliency is the ability of the species to withstand environmental and 
demographic stochasticity (for example, wet or dry, warm or cold 
years), redundancy is the ability of the species to withstand 
catastrophic events (for example, droughts, large pollution events), 
and representation is the ability of the species to adapt to both near-
term and long-term changes in its physical and biological environment 
(for example, climate conditions, pathogens). In general, species 
viability will increase with increases in resiliency, redundancy, and 
representation (Smith et al. 2018, p. 306). 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 FWS-R4-ES-
2023-0103 on https://www.regulations.gov and at https://ecos.fws.gov/ecp/species/9832.

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.

Species Needs

    The SSA report contains a detailed discussion of the Miami cave 
crayfish individual and population requirements (Service 2022, pp. 23-
27); we provide a summary here. Based upon the best available 
scientific and commercial information, and acknowledging existing 
ecological uncertainties, the resource and demographic needs for 
breeding, feeding, sheltering, and dispersal of the Miami cave crayfish 
are characterized as:
    <bullet> Sufficient freshwater quality and availability to support 
a suitable aquatic environment for movement and healthy individuals.
    <bullet> Sufficient quantities of mega-porous limestone to provide 
the structure needed for Miami cave crayfish movement and shelter. The 
Miami cave crayfish has adapted to these mega-porous limestone layers 
in the Biscayne Aquifer, which provides them with structures through 
which juvenile and adult Miami cave crayfish can travel between areas 
within the aquifer system, facilitating connectivity; microhabitats in 
which individuals can shelter or hide from intra- and interspecific 
threats; and enhanced groundwater flow for improved water quality and 
food availability (Loftus and Trexler 2004, p. 49, Hobbs and Means 
1972, p. 401; Caine 1978, pp. 323, 325, Fish and Stewart 1991, p. 47; 
Wacker et al. 2014, pp. 27-40).
    <bullet> Sufficient quantities of detritus filtering from the 
surface into the subterranean aquifer to support both the Miami cave 
crayfish and the amphipods and isopods upon which the crayfish may also 
feed.
    Miami cave crayfish abundance is limited to the availability and 
condition of these resources in the Biscayne Aquifer along the Atlantic 
Coastal Ridge. While there is high confidence in these identified 
species needs, uncertainty exists as to the exact parameters and 
quantities needed for each of these factors, as no ecological or 
quantitative studies have been completed on them.

Threats

    The main threats affecting the Miami cave crayfish are related to 
shifts in climate largely as a result of increasing greenhouse gas 
emissions. Saltwater intrusion into the Biscayne Aquifer as a result of 
sea level rise, more frequent tidal flooding (increase of tides above 
the mean high tide), and increasing intensity of storm events (such as 
hurricanes) are the predominant threats to the Miami cave crayfish and 
its habitat. Additional threats with greater uncertainty and likely 
less severity to the Miami cave crayfish include water quality 
degradation, groundwater pumping, and modification of surface cover 
resulting from urban development. We also evaluated existing ongoing 
conservation measures and regulatory mechanisms. In the SSA report, we 
considered additional threats: modification of subterranean limestone, 
competition and predation, disease, and overutilization. We concluded 
that, as indicated by the best available scientific and commercial 
information, these additional threats are currently having little to no 
impact on the Miami cave crayfish, and thus their overall effect now is 
expected to be minimal and the best available information does not 
indicate this will change in the future.

[[Page 64860]]

For full descriptions of all threats and how they impact the Miami cave 
crayfish, please see the SSA report (Service 2022, pp. 27-78).
Saltwater Intrusion
    Although the salinity tolerance of Miami cave crayfish has not been 
assessed, surrogate species, such as the closely related Everglades 
crayfish (Procambarus alleni), indicate it is highly unlikely that the 
species could persist in the salinity levels found in areas affected by 
saltwater intrusion. Surface-dwelling crayfish are able to persist in 
saline environments in the short-term, but exposure to salinity levels 
above naturally occurring levels for long periods of time can cause 
inhibition of growth, limited to no reproduction, lower hatching 
success, and mortality (Vesel[yacute] et al. 2017, pp. 4-5). 
Additionally, when comparing the salinity levels found in the closely 
related, brackish-water-dwelling Everglades crayfish to salinity levels 
found in areas of the Biscayne Aquifer affected by saltwater intrusion, 
the salinity levels in areas affected by saltwater intrusion far 
exceeded tolerances of the Everglades crayfish (Hendrix and Loftus 
2000, p. 194; Service 2022, p. 69). This indicates that a closely 
related, saline-tolerant species of crayfish would not be able to 
tolerate the salinity levels that the Miami cave crayfish would be 
experiencing in areas of saltwater intrusion. Therefore, we concluded 
the Miami cave crayfish likely cannot persist in areas affected by 
saltwater intrusion, because it needs sufficient freshwater in order to 
survive and reproduce.
    Saltwater intrusion occurs when saltwater enters into a freshwater 
aquifer system. Four main processes contribute to the intrusion of 
saltwater into aquifer systems like the Biscayne Aquifer: (1) the 
escape of saltwater that had been previously stored in sedimentary 
rocks, (2) the gradual advance of oceanwater along the base of the 
aquifer as a result of lowering freshwater levels within the aquifer 
and sea level rise, (3) seepage of hypersaline (extremely salty) water 
from coastal saltwater marshes, and (4) leakage of saltwater from canal 
systems that feed into the ocean (Prinos et al. 2014, pp. 12-16). 
Processes two and four are of greatest concern to the Biscayne Aquifer 
within the range of Miami cave crayfish because of large sea level rise 
projections, the potential effects from the planned construction of a 
curtain wall west of the Atlantic Coastal Ridge (discussed below), and 
the extensive canal network in the area. Additionally, the area's low 
altitude and topographic gradient, high permeability, and the bordering 
saltwater sources of the Atlantic Ocean, Biscayne Bay, and Florida Bay 
make it especially susceptible to saltwater intrusion (Prinos et al. 
2014, p. 2).
    Sea level rise--Regional sea levels could rise between 1.41 ft 
(0.43 m) and 4.53 ft (1.38 m) by 2070. Temperatures are predicted to 
rise as well, while dry seasons, droughts, and tropical storms are 
likely to become more extreme (IPCC 2014, pp. 1452-1456; Infanti et al. 
2020, entire; IPCC 2021, pp. 32, 33). The cumulation of all of these 
climatic factors is highly likely to result in the continued inland 
migration of the saltwater interface in the Biscayne Aquifer along the 
Atlantic Coastal Ridge. The loss of habitat along the eastern edge of 
the Atlantic Coastal Ridge is particularly impactful since these 
coastal areas exhibit the greatest aquifer depths and, thus, the 
greatest overall quantity of Miami cave crayfish habitat.
    Curtain wall--In the western range of the species, a project 
started in 2012 that may impact saltwater intrusion is the construction 
of a 19- to 31-mile (31- to 50-kilometer) curtain wall west of the 
Atlantic Coastal Ridge. The curtain wall's purpose is to manage waters 
within the Everglades wetland ecosystem and protect the coastal 
urbanized area of Miami-Dade County from flooding (Owosina 2020, 
unpaginated). The project is expected to be completed in five-to-10-
mile increments within the next ten years if funding can be secured. 
The curtain wall will alter the superficial water flow that reaches the 
Miami-Dade area, but we are not certain of the level of effects or 
dynamics to the Biscayne Aquifer, particularly to the east of the 
structure on the Atlantic Coastal Ridge where water flow from the 
Everglades wetland ecosystem in the east may be reduced. Groundwater 
will still flow under the curtain wall. The recommended configuration 
for further study (a 27-mile South scenario) will include gaps in the 
curtain wall and is seeking to balance restoration and flood control 
while mitigating impacts to Biscayne Bay, Taylor Slough, and water 
supply (South Florida Water Management District 2023, p. 9-89-9-92).
    Currently, a general eastward and southeastward direction of 
groundwater flow along the Atlantic Coastal Ridge counters the 
encroachment of saltwater from the ocean (Prinos et al. 2014, p. 6). 
Weakening of this eastward and southeastward water flow may cause 
increased saltwater intrusion and subsequent loss of Miami cave 
crayfish habitat. In addition, any potential loss of freshwater 
recharge provided by the Everglades wetland ecosystem may drop the 
groundwater levels of the Biscayne Aquifer on the Atlantic Coastal 
Ridge, further contributing to saltwater intrusion.
    Canals--Modern water management and its impact on saltwater 
intrusion has a long history in the Miami area, beginning with the 
coordinated draining of the Everglades wetland ecosystem in 1845. 
Historically, canals along the Atlantic Coastal Ridge aided in draining 
the adjacent wetland systems, which, along with groundwater pumping, 
led to a permanent drop of about 9.5 ft (2.9 m) in regional groundwater 
levels within the Biscayne Aquifer (Prinos et al. 2014, pp. 2, 64). As 
a result, saltwater intrusion began to expand inward from the coast 
(Prinos et al. 2014, p. 64). Concurrently, saltwater flowed up the 
expanded canal systems from the ocean and seeped into the surrounding 
aquifer system (Prinos et al. 2014, p. 64).
    Today's water management system is operated by the South Florida 
Water Management District and includes a complex, interconnected 
network of water conservation areas, well-fields, water control 
structures, levees, pumps, and canals. Despite the installation of 
salinity control structures along most of the tidal canal system in 
Miami-Dade County, saltwater seepage from canals into the adjacent 
aquifer system is still one of the primary mechanisms by which 
saltwater intrusion occurs in the region (Prinos et al. 2014, pp. 42, 
43, 47-55, 66).
    In summary, saltwater intrusion is the primary threat to the Miami 
cave crayfish, because it causes complete loss of habitat and is 
projected to get worse in the future; and the species has no dispersal 
potential outside of its current, restricted range.
Groundwater Pumping
    Residents of Miami-Dade County have been pumping freshwater out of 
the Biscayne Aquifer for residential, agricultural, industrial, 
municipal, and recreational use since the first public supply wells 
were drilled in 1899 (Prinos et al. 2014, p. 18; Hughes and White 2016, 
pp. 27-29). As the population has grown, so too has the demand for 
freshwater. Public groundwater withdrawals increased in line with 
population growth until 2006 when demand on the aquifer was mitigated 
by stricter water use regulations (Bradner et al. 2005, p. 1; Prinos et 
al. 2014, p. 7).
    Although 90 percent of the freshwater consumed by Miami-Dade County 
residents is pumped from the Biscayne Aquifer, these are not the only 
South

[[Page 64861]]

Florida populations drawing from the aquifer's groundwater reserves. 
Over 4 million people in Broward and Palm Beach Counties also rely on 
the Biscayne Aquifer for their freshwater needs, and groundwater piped 
from the Biscayne Aquifer to the Florida Keys serves as the main source 
of potable water for all of Monroe County (Bradner et al. 2005, p. 1; 
Prinos et al. 2014, p. 7). Consequently, the U.S. Environmental 
Protection Agency (EPA) has designated the Biscayne Aquifer as a sole-
source aquifer (i.e., the only viable groundwater source in the region; 
EPA 2016, entire).
    As mentioned in the Canals discussion above, groundwater pumping 
was part of what caused an estimated 9.5-ft (2.9-m) drop in water 
levels compared to levels before the drainage of the Everglades (Prinos 
et al. 2014, p. 17). This drop in water level roughly equates to an 11 
percent loss in potential Miami cave crayfish habitat since the 1840s 
(Service 2022, pp. 53). An 11 percent loss in habitat from potential 
historical levels is significant because the species has an already 
limited range.
    In addition to causing direct loss of habitat, groundwater 
withdrawal can exacerbate the effects of saltwater intrusion. Lower 
freshwater levels as a result of groundwater withdrawal can cause 
saltwater intrusion to move further inland (Prinos et al. 2014, pp. 12-
16). Lower freshwater levels also act synergistically with sea level 
rise to increase the rate of saltwater intrusion encroachment into the 
aquifer.
    The most uncertain but potentially most impactful result of 
groundwater pumping is from the pumping process itself. Mortality 
events are possible for Miami cave crayfish that get sucked into a 
water pump system. In fact, the original specimens from which the 
species was first described were deceased individuals collected from a 
water pump trap (Hobbs 1971, p. 114). However, public water supply 
wells may have water pumps that are deep enough to avoid impacting the 
Miami cave crayfish. For example, the Miami-Dade Water and Sewer 
Department Northwest Wellfield has wells constructed with 46 feet of 
casing, meaning water is being pumped deeper than 46 feet (Krupa et al. 
2001, p. 3). The deepest Miami cave crayfish have been collected from 
is 36 feet deep. Therefore, public water supply wells may not have a 
significant effect on the species depending on the depth of the well. 
Private water supply, agricultural, or other types of wells that are 
shallower may have a more significant impact to the species. Overall, 
the extent of mortality resulting from water pumping is unknown but 
could be having ongoing impacts on the species.
Water Quality Degradation
    The high permeability of the Biscayne Aquifer, particularly along 
the Atlantic Coastal Ridge, makes its groundwater vulnerable to 
contamination from surficial inputs, belowground septic tanks, and 
adjoining water bodies (Bradner et al. 2005, entire; Potter et al. 
2007, p. 1306; Florida Department of Environmental Protection 2019, 
entire). In particular, the sandy soils typical to the Atlantic Coastal 
Ridge contain relatively small amounts of soil organic matter and 
exhibit low water retention, increasing the potential for leaching of 
surface contaminants into groundwater below (Marchi et al 2016, pp. 
237-238). Additionally, the high interconnectivity of the Biscayne 
Aquifer facilitates the relatively rapid and extensive spread of 
contaminants well beyond their point of origin (Harvey et al. 2008, 
entire; Shapiro et al. 2008, entire).
    Pharmaceuticals, pesticides, volatile organic compounds, excess 
nutrients, and excess trace elements are introduced into groundwater 
throughout Miami-Dade County by a variety of land uses associated with 
development, agriculture, and recreation. These contaminants are 
concentrated in canals and other water bodies from which they seep into 
the Biscayne Aquifer. A current and comprehensive regional assessment 
of groundwater contamination across the endemic range of Miami cave 
crayfish is not available; however, there are many sources of 
pollutants including human wastewater, agriculture, and golf courses, 
among others (Service 2022, pp. 59-61).
    Using other crayfish and crustaceans as analogues, we predict that 
Miami cave crayfish likely experience increased morbidity, mortality, 
and reproductive loss when exposed to anthropogenic contaminants 
(Service 2022, p. 58). However, although pollutants may be a 
significant threat to the species, the scope and magnitude of this 
threat is not known because of the lack of information on the levels of 
pollutants across the range of the Miami cave crayfish.
Modification of Surface Cover
    The subterranean communities supporting Miami cave crayfish are 
dependent on the influx of detritus from surficial sources. When 
surface vegetation is lost or is blocked by impermeable land cover from 
entering subterranean habitats, the food supply of the species can be 
compromised. The majority of the surface cover above Miami cave 
crayfish habitat is impermeable cover (greater than 85 percent). 
Because of the large amount of impermeable cover above subterranean 
habitat, there is likely less detritus available for the Miami cave 
crayfish. However, the best available information does not indicate 
that the amount of detritus filtering down into Miami cave crayfish 
habitat has been significantly reduced because of impermeable cover.
Summary of Threats
    The primary threat to the Miami cave crayfish is saltwater 
intrusion as a result of sea level rise, increased high tide flooding, 
increased intensity of storm events, groundwater pumping, and altered 
hydrologic flows. Saltwater intrusion results in a complete loss of 
habitat, which is significant because the Miami cave crayfish has a 
restricted range. Additional threats with greater uncertainty and 
likely less severity include mortality from groundwater pumps, water 
quality degradation, and impermeable surface cover limiting detritus 
flow into subterranean habitat.

Current Conditions

    The current condition of the Miami cave crayfish is described in 
terms of population resiliency, redundancy, and representation across 
the species. The analysis of these conservation principles to 
understand the species' current viability is described in more detail 
in the Miami cave crayfish SSA report (Service 2022, pp. 78-93).
    Historically, all Miami cave crayfish were likely part of one 
metapopulation that had some degree of connectivity. Currently, the 
Miami cave crayfish still exists in one population restricted to the 
Biscayne Aquifer along the Atlantic Coastal Ridge. However, a series of 
canals cross the Atlantic Coastal ridge reduce connectivity. For the 
purposes of this assessment, we divided the Atlantic Coastal Ridge into 
seven analysis units to assess resiliency of the Miami cave crayfish. 
Reduced connectivity from canals creates semi-isolated areas, which led 
us to delineating seven analysis units using the network of canals as 
boundaries (Service 2022, p. 22).
    To determine the current resiliency for the seven analysis units, 
we assessed habitat metrics, such as freshwater availability, detritus 
availability, freshwater quality, and habitat quantity. For each metric 
if greater than 79 percent of the measured factor is in a natural, 
anthropogenically unaltered state it ranked as a high condition, 51-79 
percent ranked as a moderate condition, and 50 percent or less ranked 
as a low condition.

[[Page 64862]]

Freshwater Availability
    Saltwater intrusion is the primary threat to the Miami cave 
crayfish because it reduces the amount of freshwater available for the 
species' habitat. Currently, saltwater intrusion is affecting six of 
the seven analysis units for the Miami cave crayfish (Service 2022, p. 
68; Prinos 2019, entire). Two units have greater than 50 percent of 
habitat affected by saltwater intrusion, four units have 17 to 26 
percent of habitat affected, and two units have 0 to 5 percent of 
habitat affected (Service 2022, p. 88). Overall, a majority of Miami 
cave crayfish habitat is currently unaffected by saltwater intrusion 
and is considered to be in a high condition.
Availability of Detritus and Freshwater Quality
    Currently, we have little to no information on whether the amount 
of detritus filtering down into Miami cave crayfish habitat has been 
significantly reduced because of impermeable cover; effects of 
pollution on water quality; or mortality resulting from groundwater 
pumping or subsurface modification activities, such as mining. While 
these stressors likely affect the resiliency of the Miami cave 
crayfish, we do not know the direct effects to the species and its 
needs.
    Because we do not know the direct effects impermeable cover, 
pollutants, and activities that cause mortality have on the Miami cave 
crayfish, we estimated the magnitude of these stressors on the species 
and its needs based on indirect measures.
    To assess the availability of detritus, we compared the amount of 
permeable cover currently above Miami cave crayfish habitat to the 
amount of permeable cover that was historically present. Each analysis 
unit has less than 37 percent surface area remaining that is permeable 
cover (Service 2022, p. 85). Permeable cover is defined as surface 
cover with vegetation that provides detritus directly into the 
subterranean habitat. All analysis units are considered in a low 
condition for the quality of surface cover. We acknowledge that we do 
not know the amount of detritus needed by the Miami cave crayfish nor 
the current amount of available detritus in the Biscayne Aquifer; 
therefore, there is significant uncertainty in this metric.
    To assess water quality, we estimated the number of potential 
sources of pollution within the range of the species. We categorized 
different land use types, such as agriculture, by the pollutants they 
may be inputting into the Biscayne Aquifer. Then, we measured the 
amount of surface cover in each analysis unit that is likely inputting 
pollutants into the aquifer. Each analysis unit is in a low condition 
for water quality because of the large number of potential inputs of 
pollutants into Miami cave crayfish habitat. We acknowledge that we do 
not know the water quality parameters needed by the Miami cave crayfish 
nor the amount of pollution within the range of the species; therefore, 
there is significant uncertainty in this metric.
Habitat Quantity
    To assess habitat quantity, we estimated the total physical 
volumetric habitat available to the species (i.e., the total 
subterranean karstic limestone that is submerged in the Biscayne 
aquifer). We used the most recent available data for the depth of the 
Biscayne Aquifer on the Atlantic Coastal Ridge (Hughes and White 2016, 
p. 26) and subtracted out certain land uses, like limestone mines, and 
sewer line infrastructure (Miami-Dade County 2018, entire and Miami-
Dade County 2021a, entire). We then compared the amount of 
subterranean, karstic limestone aquifer habitat currently available to 
the amount that was historically present. All analysis units are in a 
high condition relative to habitat quantity (Service 2022, p. 80).
Resiliency, Redundancy, and Representation
    Although we found overall resilience to be low in all analysis 
units, we determined the Miami cave crayfish currently has sufficient 
resiliency to withstand environmental and demographic stochasticity. A 
majority of the Miami cave crayfish range is in a high condition for 
freshwater availability and habitat quantity is in a high condition for 
all seven analysis units. Our measures of available detritus and water 
quality are in a low condition across the range. However, we put 
greater weight on the freshwater availability and habitat quantity 
metrics because they are direct measures of the species' needs, whereas 
we put less weight on the availability of detritus and freshwater 
quality metrics because they are indirect measures of the species' 
needs with significant assumptions. We then assessed the best available 
demographic data for the Miami cave crayfish.
    Surveys since 2000 indicate the species is present in all analysis 
units except for the one analysis unit most impacted by saltwater 
intrusion (Service 2022, p. 21). The most comprehensive surveys were 
completed in the period 2000-2004, confirming presence of the species 
distributed throughout the range (Service 2022, p. 21). Subsequently, 
one anecdotal observation in 2009 along with a survey effort in 2018 
confirmed presence in a total of four analysis units spread throughout 
the range (Service 2022, p. 21). The effects of impermeable land cover 
and pollution in the Biscayne Aquifer have been impacting the Miami 
cave crayfish for multiple decades; therefore, the continued presence 
of the species throughout the range indicates it currently has 
sufficient resiliency to these stressors.
    In summary, the Miami cave crayfish currently has sufficient 
resiliency to withstand environmental and demographic stochasticity 
because there is enough freshwater and habitat available. Despite our 
measures of available detritus and water quality being in low 
condition, the Miami cave crayfish has consistently been found 
throughout its range through multiple decades of impermeable land cover 
and pollution in the Biscayne Aquifer, indicating that it currently has 
sufficient resiliency to these stressors. We combined our habitat 
metric analysis with the best available information on the demographics 
of the species to determine that the Miami cave crayfish currently has 
sufficient resiliency to withstand environmental and demographic 
stochasticity.
    The Miami cave crayfish currently has limited ability to withstand 
catastrophic events and adapt to a changing environment because it has 
naturally low redundancy and representation due to its high level of 
endemism. The narrowly distributed, isolated nature of the single 
population of the species indicates it has limited ability to withstand 
stochastic or catastrophic events through dispersal. Because the 
species evolved in a unique subterranean aquifer system with little 
historical variation, we conclude that it has low potential to adapt to 
environmental changes to its habitat. As a single-aquifer endemic with 
no dispersal opportunities outside the current range, the species 
depends entirely on the continued availability of its habitat along the 
Atlantic Coastal Ridge. Even though redundancy and representation are 
inherently low for the Miami cave crayfish because of its endemism, 
they are both similar to historical levels.

Future Condition

    In the SSA report, we analyzed four scenarios that incorporated 
changes in saltwater intrusion caused by sea level rise, urbanization, 
water quality condition caused by pollution, and water quantity 
condition caused by groundwater pumping. The main driver

[[Page 64863]]

of the future condition of the species is the movement of saltwater 
intrusion further inland because of sea level rise. Urbanization, 
pollution levels, and groundwater pumping levels do not change 
significantly into the future because they are already at high levels 
and there is limited capacity for more development, though they may 
increase if the limited available land is developed. Subsequently, we 
focus on the future effects of saltwater intrusion in this document. 
Further discussion of future changes in urbanization, water quality 
condition, and water quantity condition can be found in the SSA report 
(Service 2022, pp. 94-100).
    As sea level rises, more Miami cave crayfish habitat will become 
unsuitable because saltwater will intrude further inland into the 
Biscayne Aquifer. The Biscayne Aquifer has varied depth, ranging from 
50 ft (15 m) in the most inland extent of the range to 90 ft (27 m) in 
the most coastal extent of the range (Hughes and White 2016, p. 26). 
Because the aquifer is deepest closer to the coast, there is more Miami 
cave crayfish habitat within this area. Coastal habitat will be 
increasingly impacted by saltwater intrusion, which is significant 
because the largest volume of habitat will be lost first.
    For our evaluation of future condition, we used modeled projections 
of sea level rise (Sweet et al. 2017, entire; Sweet et al. 2018, 
entire). We modeled threats to the year 2070, representing a 50-year 
time horizon, corresponding to the range of available urbanization and 
climate change model forecasts (Carr and Zwick 2016, entire; Sweet et 
al. 2017, entire; Sweet et al. 2018, entire). In addition, 50 years 
represents an appropriate biological timeframe during which responses 
of the species to potential changes in habitat can be reasonably 
assessed. Although the lifespan and generation time for Miami cave 
crayfish are currently unknown, estimates for these measures based on 
those reported for other subterranean crayfish taxa (Taylor et al. 
1996, p. 27; Huryn et al. 2008, pp. 1, 12-15; Longshaw and Stebbing 
2016, p. 68) suggest that three generations of the species would likely 
be represented in a 50-year time span.
    No projections currently exist that predict the extent of saltwater 
intrusion into the Biscayne Aquifer by 2070, so we estimated the inland 
movement of the saltwater interface from its 2018 position (Prinos 
2019, unpaginated) based on the projections of regional sea level rise, 
the degree of aquifer drawdown, and anthropogenic interventions 
potentially altering saltwater intrusion. The regional sea level rise 
scenarios adopted from Sweet et al. (2017 and 2018) (e.g., 
Intermediate, Intermediate High, and Extreme scenarios) encompass the 
extent of sea level rise predicted by the low-end and high-end likely 
ranges for the representative concentration pathway (RCP) 4.5 and RCP 
8.5 emissions scenarios for future global temperatures projected by the 
Intergovernmental Panel on Climate Change assessment report 5 (Sweet et 
al. 2018, p. 24).
    After we had completed our SSA, version 1.0, new sea level rise 
projections were made publicly available (Sweet et al. 2022, entire). 
We compared the Sweet et al. (2017, entire) sea level rise projections 
to the new updated Sweet et al. (2022, entire) projections and added 
this comparison summary as an appendix to the SSA report (Service 2023, 
version 1.1). The Sweet et al. (2022, entire) sea level rise scenarios 
project lower sea level rise in 2070 when compared to projections from 
Sweet et al. (2017, entire). However, including the additional effects 
of high tide flooding, similar loss of habitat would be expected as 
seen in our projections using Sweet et al. 2017.
    The intermediate sea level rise scenario (1.41-ft (0.43-m) regional 
sea level rise projection) is represented in the SSA report by scenario 
4; the intermediate-high sea level rise scenario (2.49-ft (0.76-m) 
regional sea level rise projection) is represented in the SSA report by 
scenarios 1 and 2; and the extreme sea level rise scenario (4.53-ft 
(1.38-m) regional sea level rise projection) is represented by scenario 
3 (Sweet et al. 2017 and 2018, entire).
    In scenario 4, saltwater intrusion will cause increased habitat 
loss in the two analysis units in a low condition and the one analysis 
unit in a moderate condition, while also causing one high condition 
unit to drop to a moderate condition (Service 2022, pp. 106-107; table 
1). In scenarios 1 and 2, saltwater intrusion will cause two units to 
decrease from a high to moderate condition, one unit will decrease from 
a moderate to a low condition, and one unit will decrease from a low to 
extirpated condition. In scenario 3, saltwater intrusion will cause 
three units to be completely extirpated and the remaining four units to 
drop to a low condition, meaning over 50 percent of the habitat in 
those units would be lost (Service 2022, pp. 104-105; table 1). In all 
of our future scenarios, a significant loss of habitat would result 
from saltwater intrusion (table 1).

    Table 1--Condition of Freshwater Availability for the Current Condition and the Future Condition for Each
                           Scenario for Each Analysis Unit of the Miami Cave Crayfish
----------------------------------------------------------------------------------------------------------------
                         Current
                        condition:      Scenario 4: \1\    Scenario 1: \2\    Scenario 2: \2\    Scenario 3: \3\
   Analysis unit        freshwater         freshwater         freshwater         freshwater        freshwater
                       availability       availability       availability       availability      availability
----------------------------------------------------------------------------------------------------------------
1.................  High.............  High.............  Moderate.........  Moderate.........  Low.
2.................  High.............  High.............  Moderate.........  Moderate.........  Low.
3.................  High.............  Moderate.........  Moderate.........  Low..............  Low.
4.................  High.............  High.............  High.............  High.............  Low.
5.................  Low..............  Low..............  Extirpated.......  Extirpated.......  Extirpated.
6.................  Moderate.........  Moderate.........  Low..............  Low..............  Extirpated.
7.................  Low..............  Low..............  Low..............  Low..............  Extirpated.
----------------------------------------------------------------------------------------------------------------
Scenarios 4 and 3 represent the upper and lower bounds of projected scenarios for the future condition of the
  species:
\1\ Scenario 4: Intermediate sea level rise scenario (1.41-ft (0.43-m) regional sea level rise).
\2\ Scenarios 1 and 2: Intermediate-high sea level rise scenario (2.49-ft (0.76-m) regional sea level rise).
\3\ Scenario 3: Extreme sea level rise scenario (4.53-ft (1.38-m) regional sea level rise).

    Resiliency, redundancy, and representation would all be reduced in 
the future because of habitat loss due to saltwater intrusion. With 
less habitat available, Miami cave crayfish abundance would likely 
decline. Fewer Miami cave crayfish in the aquifer and less available 
habitat reduces the ability of the species to withstand environmental 
and demographic stochasticity and also its ability to withstand 
catastrophic events. A lower

[[Page 64864]]

population size also reduces the genetic diversity of the species, 
further limiting its adaptive capacity. Additionally, the Miami cave 
crayfish has no ability to disperse outside of its current range, also 
limiting its ability to adapt to changing conditions. Overall, the 
Miami cave crayfish will likely be significantly more vulnerable to 
stressors in the future because of habitat loss due to increased 
impacts of saltwater intrusion due to sea level rise.
    We note that, by using the SSA framework to guide our analysis of 
the scientific information documented in the SSA report, we have 
analyzed the cumulative effects of identified threats and conservation 
actions on the species. To assess the current and future condition of 
the species, we evaluate the effects of all the relevant 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

    Regulations that help to protect Miami cave crayfish habitat 
include water management regulations that reduce groundwater withdrawal 
and pollution.
    The South Florida Water Management District is responsible for 
water management in Miami-Dade County and regulates water use and 
production throughout the region. In 2007, the South Florida Water 
Management District passed a rule that prevents water consumers from 
sourcing new or additional supplies of freshwater that are recharged by 
the Everglades ecosystem. Water users are now required to use 
alternative sources, such as recycled water, treated wastewater pumped 
into the Biscayne Aquifer for recharge purposes, groundwater reserves 
in the Floridan aquifer system, or general water conservation practices 
(South Florida Water Management District 2008, entire; Hughes and White 
2016, pp. 2-3). The measure has already resulted in decreased rates of 
public water withdrawal from the Biscayne Aquifer (Bradner et al. 2005, 
p. 1; Prinos et al. 2014, p. 7).
    Another key regulation adopted by the South Florida Water 
Management District that counters freshwater withdrawal from the 
Biscayne Aquifer is its year-round landscape watering restrictions 
(Chapter 40E-24, Florida Administrative Code). These restrictions 
stipulate specific times that landscape watering is permitted, thus 
restricting the amount of groundwater that can be withdrawn from those 
using public or privately owned water utility systems or wells. 
However, some large sources of water consumption are exempted by these 
regulations, namely athletic play areas (e.g., golf courses, sports 
facilities, equestrian and livestock arenas), agricultural operations 
with consumptive use permits, and water users practicing hand watering 
(e.g., with hoses) (South Florida Water Management District 2021a, 
unpaginated).
    Biscayne Aquifer groundwater has limited protective benefits from 
pollution under Federal, State, and county regulations. Most regulatory 
protections focus on surface water quality, which offers indirect 
benefits to the quality of freshwater within the Biscayne Aquifer 
system. The primary laws and ordinances pertaining to water quality 
protection that directly or indirectly affect groundwater quality in 
the endemic range of Miami cave crayfish include (but are not limited 
to):
    <bullet> Comprehensive Environmental Response, Compensation, and 
Liability Act of 1980 (the Superfund law) (42 U.S.C. 9601 et seq.): 
identifies, evaluates, and cleans up sites contaminated with hazardous 
substances.
    <bullet> Resource Conservation and Recovery Act (42 U.S.C., ch. 82, 
sec. 6901 et seq.): establishes standards for the treatment, storage, 
and disposal of hazardous waste from municipal and industrial sources, 
including that contained in underground storage tanks.
    <bullet> Safe Drinking Water Act (42 U.S.C. 300f): establishes 
national primary drinking water regulations for contaminants that may 
cause adverse public health effects, including mandatory requirements 
related to maximum contaminant levels and treatments.
    <bullet> Clean Water Act of 1972 (33 U.S.C. 1251 et seq.): 
indirectly benefits groundwater quality by protecting the quality of 
surficial waters.
    <bullet> The Everglades Forever Act (Section 373.4592(4)(f), F.S.): 
establishes best management practices in the Everglades Agricultural 
Area, which is underlaid by the Biscayne Aquifer that indirectly 
benefits from these regulations.
    <bullet> The Grizzle-Figg Statute (Section 403.086, F.S.): outlines 
requirements for safe sewage disposal facilities and treatment of 
discharges from these sewage facilities.
    <bullet> Identification of Impaired Surface Waters (Section 62-303, 
F.S.): establishes water quality standards and protocols by which 
Florida assesses, lists, and delists impaired surface waters, which 
indirectly protects adjacent aquifer systems.
    <bullet> Miami-Dade County Ordinance for Florida-Friendly 
Fertilizer Use for Urban Landscapes: regulates fertilizer application 
and use in the incorporated and unincorporated areas of the county.
    <bullet> Miami-Dade County Wellfield Protection Regulations: 
prohibits or limits activities that use or store hazardous materials, 
generate hazardous waste, excavate to any depth, or require the 
installation of septic tanks within a wellfield protection area.
    Currently, there are no conservation efforts specific to the Miami 
cave crayfish.
    The Miami cave crayfish is listed in the State Wildlife Action Plan 
as a species of greatest concern (Florida Fish and Wildlife 
Conservation Commission 2019, p. 163).

Determination of Miami Cave Crayfish 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 in danger of extinction throughout all or a significant portion 
of its range, and a ``threatened species'' as a species 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 an endangered 
species or a threatened species because of any of the following 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence.

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 impacts from saltwater intrusion caused by 
rising sea levels is the most substantial threat to the Miami cave 
crayfish viability. In the foreseeable future, we anticipate that 
saltwater intrusion will continue to move inland as climate-

[[Page 64865]]

change-induced sea level rise continues, causing the loss of Miami cave 
crayfish habitat and having the greatest influence on Miami cave 
crayfish viability. We also considered the effects of development, 
pollution in the Biscayne Aquifer, activities that can cause mortality, 
and minor threats including modification of subterranean limestone, 
competition and predation, disease, and overutilization for their 
cumulative effects.
    The Miami cave crayfish exists in one population restricted to the 
Biscayne Aquifer along the Atlantic Coastal Ridge. Pollution and 
impermeable surface cover may be negatively affecting resiliency of the 
species by decreasing water quality and limiting the detritus filtering 
into the aquifer. However, these impacts are highly uncertain, so we 
put the greatest weight on habitat availability and available survey 
data. Currently, two analysis units are significantly (greater than 50 
percent) affected by saltwater intrusion with five analysis units not 
significantly (0 to 26 percent) affected by saltwater intrusion. 
Overall, a majority of the Miami cave crayfish range is currently 
unaffected by saltwater intrusion and is considered to be in a high 
condition. Additionally, survey data indicate the Miami cave crayfish 
is present throughout the range despite multi-decadal threats impacting 
the species. We conclude that there is sufficient habitat available to 
the species and the Miami cave crayfish is still distributed throughout 
its range; therefore, it currently has a sufficient level of 
resiliency.
    Based on its limited geographical range, redundancy and 
representation are inherently low for the Miami cave crayfish and 
likely similar to historical levels. Redundancy has been slightly 
reduced from historical levels because saltwater intrusion has reduced 
the available habitat near the coast, negatively impacted the ability 
of the species to withstand catastrophic events. Similarly, current 
representation has been slightly reduced from historical levels because 
habitat loss reduces the population size of the species, decreasing the 
amount of potential genetic diversity. Overall, redundancy and 
representation remain similar to historical levels. Given the current 
resiliency, redundancy, and representation of the Miami cave crayfish 
across its range, we conclude that the species is not currently in 
danger of extinction throughout its range.
    We next considered whether the species is likely to become in 
danger of extinction within the foreseeable future throughout all of 
its range. In considering the foreseeable future for the Miami cave 
crayfish, we analyzed expected changes in sea level rise and the 
resulting inland movement of saltwater intrusion out to 2070 (Service 
2022, pp. 100-107). We determined that this timeframe represents a 
period for which we can reliably predict both the threats to the 
species and the species' response to those threats.
    By 2070, the Miami cave crayfish is projected to lose significant 
amounts of habitat as saltwater encroaches further inland into the 
Biscayne Aquifer. Projected habitat losses range from losing close to 
50 percent of the habitat in one additional analysis unit in the 
intermediate sea level rise scenario (scenario 4), to losing greater 
than 50 percent of all available habitat in the extreme sea level rise 
scenario (scenario 3). Intermediate scenarios 1 and 2 are projected to 
have only one remaining analysis unit in a high condition, one 
extirpated unit, and the remaining units being in either a moderate or 
low condition, meaning a majority of the habitat would be affected by 
saltwater intrusion. The Miami cave crayfish already has a limited 
range with naturally low redundancy and representation levels, 
ultimately making it completely dependent on the availability of its 
habitat. Therefore, the projected loss of habitat in the foreseeable 
future would leave the species extremely vulnerable to stochastic or 
catastrophic events. Additionally, the Miami cave crayfish has no 
ability to disperse outside of its current range and is unlikely to be 
able to adapt to a saltwater environment. Thus, after assessing the 
best available information, we conclude that the Miami cave crayfish is 
not currently in danger of extinction but is likely to become in danger 
of extinction within the foreseeable future throughout all of its 
range.

Status Throughout a Significant Portion of Its Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is in danger of extinction or likely to become so 
in the foreseeable future throughout all or a significant portion of 
its range. The court in Center for Biological Diversity v. Everson, 435 
F. Supp. 3d 69 (D.D.C. 2020) (Everson), vacated the provision 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'' (hereafter ``Final Policy''; 79 FR 
37578, July 1, 2014) that provided if the Services determine that a 
species is threatened throughout all of its range, the Services will 
not analyze whether the species is endangered in a significant portion 
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 this analysis for the Miami cave crayfish, we choose to 
address the status question first--we consider 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 Miami cave 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 the Miami cave 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.
    We examined the following threats: saltwater intrusion, water 
quality degradation, groundwater pumping, and modification of surface 
cover resulting from urban development, including cumulative effects. 
The primary threat to the Miami cave crayfish is saltwater intrusion 
caused by rising sea levels, which is affecting the coastal analysis 
units the most currently. The other threats of water quality 
degradation, groundwater pumping, and modification of surface cover are 
largely having an effect across the range of the species. Therefore, we 
focused our evaluation on the threat of saltwater intrusion.

[[Page 64866]]

    In considering whether the threats or their effects on the species 
are greater in any biologically meaningful portion of the species' 
range, there are two analysis units affected by saltwater intrusion 
more than the other units. Currently, these two analysis units 
(portion) are significantly (greater than 50 percent) affected by 
saltwater intrusion and the other five analysis units are not 
significantly (0 to 26 percent) affected by saltwater intrusion. We 
determined this portion may have a different status than the rest of 
the range and then considered whether this portion may be significant.
    This portion is small in size relative to the entire range of the 
species; it represents less than 25 percent of the range. In addition, 
the habitat in this portion is neither unique or better quality 
compared to the rest of the range and most Miami cave crayfish have 
been observed farther inland. Therefore, we do not find this portion to 
be significant.
    Therefore, no portion of the species' range provides a basis for 
determining that the species is in danger of extinction in a 
significant portion of its range, and we determine that the species is 
likely to become in danger of extinction within the foreseeable future 
throughout all of its range. This 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 available scientific and commercial 
information indicates that the Miami cave crayfish meets the definition 
of a threatened species. Therefore, we propose to list the Miami cave 
crayfish as a threatened species in accordance with sections 3(20) and 
4(a)(1) of the Act.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened 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.
    The recovery planning process begins with development of a recovery 
outline made available to the public soon after a final listing 
determination. The recovery outline guides the immediate implementation 
of urgent recovery actions while a recovery plan is being developed. 
Recovery teams (composed of species experts, Federal and State 
agencies, nongovernmental organizations, and stakeholders) may be 
established to develop and implement recovery plans. The recovery 
planning process involves the identification of actions that are 
necessary to halt and reverse the species' decline by addressing the 
threats to its survival and recovery. The recovery plan 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. Revisions of the plan may 
be done to address continuing or new threats to the species, as new 
substantive information becomes available. The recovery outline, draft 
recovery plan, final recovery plan, and any revisions will be available 
on our website as they are completed (https://ecos.fws.gov/ecp/species/9832), or from our Florida 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 range 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.
    If this species is listed, 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 Florida would be 
eligible for Federal funds to implement management actions that promote 
the protection or recovery of the Miami cave crayfish. Information on 
our grant programs that are available to aid species recovery can be 
found at: https://www.fws.gov/service/financial-assistance.
    Although the Miami cave crayfish is only proposed for listing under 
the Act at this time, please let us know if you are interested in 
participating in recovery efforts for this species. Additionally, we 
invite you to submit any new information on this species whenever it 
becomes available and any information you may have for recovery 
planning purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7 of the Act is titled Interagency Cooperation and mandates 
all Federal action agencies to use their existing authorities to 
further the conservation purposes of the Act and to ensure that their 
actions are not likely to jeopardize the continued existence of listed 
species or adversely modify critical habitat. Regulations implementing 
section 7 are codified at 50 CFR part 402.
    Section 7(a)(2) states that each Federal action agency shall, in 
consultation with the Secretary, ensure that any action they authorize, 
fund, or carry out is not likely to jeopardize the continued existence 
of a listed species or result in the destruction or adverse 
modification of designated critical habitat. Each Federal agency shall 
review its action at the earliest possible time to determine whether it 
may affect listed species or critical habitat. If a determination is 
made that the action may affect listed species or critical habitat, 
formal consultation is required (50 CFR 402.14(a)), unless the Service 
concurs in writing that the action is not likely to adversely affect 
listed species or critical

[[Page 64867]]

habitat. At the end of a formal consultation, the Service issues a 
biological opinion, containing its determination of whether the Federal 
action is likely to result in jeopardy or adverse modification.
    In contrast, section 7(a)(4) of the Act requires Federal agencies 
to confer with the Service on any action which is likely to jeopardize 
the continued existence of any species proposed to be listed under the 
Act or result in the destruction or adverse modification of critical 
habitat proposed to be designated for such species. Although the 
conference procedures are required only when an action is likely to 
result in jeopardy or adverse modification, action agencies may 
voluntarily confer with the Service on actions that may affect species 
proposed for listing or critical habitat proposed to be designated. In 
the event that the subject species is listed or the relevant critical 
habitat is designated, a conference opinion may be adopted as a 
biological opinion and serve as compliance with section 7(a)(2).
    Examples of discretionary actions for the Miami cave crayfish that 
may be subject to conference and consultation procedures under section 
7 are land management or other landscape-altering activities on Federal 
lands administered by the U.S. Army Corps of Engineers, U.S. Coast 
Guard, U.S. Department of Transportation, and U.S. Department of 
Housing and Urban Development as well as 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. Federal agencies should coordinate with the 
local Service Field Office (see FOR FURTHER INFORMATION CONTACT) with 
any specific questions on section 7 consultation and conference 
requirements.
    It is the policy of the Services, as published in the Federal 
Register on July 1, 1994 (59 FR 34272), to identify to the extent known 
at the time a species is listed, specific activities that will not be 
considered likely to result in violation of section 9 of the Act. To 
the extent possible, activities that will be considered likely to 
result in violation will also be identified in as specific a manner as 
possible. The intent of this policy is to increase public awareness of 
the effect of a proposed listing on proposed and ongoing activities 
within the range of the species proposed for listing. Although most of 
the prohibitions in section 9 of the Act apply to endangered species, 
sections 9(a)(1)(G) and 9(a)(2)(E) of the Act prohibit the violation of 
any regulation under section 4(d) pertaining to any threatened species 
of fish or wildlife, or threatened species of plant, respectively. 
Section 4(d) of the Act directs the Secretary to promulgate protective 
regulations that are necessary and advisable for the conservation of 
threatened species. As a result, we interpret our policy to mean that, 
when we list a species as a threatened species, to the extent possible, 
we identify activities that will or will not be considered likely to 
result in violation of the protective regulations under section 4(d) 
for that species.
    At this time, we are unable to identify specific activities that 
will or will not be considered likely to result in violation of section 
9 of the Act beyond what is already clear from the descriptions of 
prohibitions and exceptions established by protective regulation under 
section 4(d) of the Act.
    Questions regarding whether specific activities would constitute 
violation of section 9 of the Act should be directed to the Florida 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

II. Proposed 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 species. The U.S. Supreme Court has noted that 
statutory language similar to the language in section 4(d) of the Act 
authorizing the Secretary to take action that she ``deems necessary and 
advisable'' affords a large degree of deference to the agency (see 
Webster v. Doe, 486 U.S. 592, 600 (1988)). Conservation is defined in 
the Act to mean the use of all methods and procedures which are 
necessary to bring any endangered species or threatened species to the 
point at which the measures provided pursuant to the Act are no longer 
necessary. Additionally, the second sentence of section 4(d) of the Act 
states that the Secretary may by regulation prohibit with respect to 
any threatened species any act prohibited under section 9(a)(1), in the 
case of fish or wildlife, or section 9(a)(2), in the case of plants. 
Thus, the combination of the two sentences of section 4(d) provides the 
Secretary with wide latitude of discretion to select and promulgate 
appropriate regulations tailored to the specific conservation needs of 
the threatened species. The second sentence grants particularly broad 
discretion to the Service when adopting one or more of the prohibitions 
under section 9.
    The courts have recognized the extent of the Secretary's discretion 
under this standard to develop rules that are appropriate for the 
conservation of a species. For example, courts have upheld, as a valid 
exercise of agency authority, rules developed under section 4(d) that 
included limited prohibitions against takings (see Alsea Valley 
Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington 
Environmental Council v. National Marine Fisheries Service, 2002 WL 
511479 (W.D. Wash. 2002)). Courts have also upheld 4(d) rules that do 
not address all of the threats a species faces (see State of Louisiana 
v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted in the legislative 
history when the Act was initially enacted, ``once an animal is on the 
threatened list, the Secretary has an almost infinite number of options 
available to [her] with regard to the permitted activities for those 
species. [She] may, for example, permit taking, but not importation of 
such species, or [she] may choose to forbid both taking and importation 
but allow the transportation of such species'' (H.R. Rep. No. 412, 93rd 
Cong., 1st Sess. 1973).
    The provisions of this proposed 4(d) rule would promote 
conservation of the Miami cave crayfish by encouraging projects and 
activities that would prevent increased saltwater intrusion into Miami 
cave crayfish habitat, improve water quality in the aquifer, and 
promote surface cover permeability. The provisions of this proposed 
rule are one of many tools that we would use to promote the 
conservation of the Miami cave crayfish. This proposed 4(d) rule would 
apply only if and when we make final the listing of the Miami cave 
crayfish as a threatened species.
    As mentioned previously in Available Conservation Measures, section 
7(a)(2) of the Act requires Federal agencies, including the Service, to 
ensure that any action they 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

[[Page 64868]]

designated critical habitat of such species. In addition, even before 
the listing of any species or the designation of its critical habitat 
is finalized, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action which is likely to 
jeopardize the continued existence of any species proposed to be listed 
under the Act or result in the destruction or adverse modification of 
critical habitat proposed to be designated for such species.
    These requirements are the same for a threatened species with a 
species-specific 4(d) rule. For example, as with an endangered species, 
if a Federal agency determines that an action is ``not likely to 
adversely affect'' a threatened species, it will require the Service's 
written concurrence (50 CFR 402.13(c)). Similarly, if a Federal agency 
determinates that an action is ``likely to adversely affect'' a 
threatened species, the action will require formal consultation with 
the Service and the formulation of a biological opinion (50 CFR 
402.14(a)).

Provisions of the Proposed 4(d) Rule

    Exercising the Secretary's authority under section 4(d) of the Act, 
we have developed a proposed rule that is designed to address the Miami 
cave crayfish's conservation needs. As discussed previously in Summary 
of Biological Status and Threats, we have concluded that the Miami cave 
crayfish is likely to become in danger of extinction within the 
foreseeable future primarily due to saltwater intrusion caused by sea 
level rise. Section 4(d) requires the Secretary to issue such 
regulations as she deems necessary and advisable to provide for the 
conservation of each threatened species and authorizes the Secretary to 
include among those protective regulations any of the prohibitions that 
section 9(a)(1) of the Act prescribes for endangered species. We find 
that, if finalized, the protections, prohibitions, and exceptions in 
this proposed rule as a whole satisfy the requirement in section 4(d) 
of the Act to issue regulations deemed necessary and advisable to 
provide for the conservation of the Miami cave crayfish.
    The protective regulations we are proposing for the Miami cave 
crayfish incorporate prohibitions from section 9(a)(1) to address the 
threats to the species. Section 9(a)(1) prohibits the following 
activities for endangered wildlife: importing or exporting; take; 
possession and other acts with unlawfully taken specimens; delivering, 
receiving, carrying, transporting, or shipping in interstate or foreign 
commerce in the course of commercial activity; or selling or offering 
for sale in interstate or foreign commerce. This proposed protective 
regulation includes all of these prohibitions because the Miami cave 
crayfish is at risk of extinction in the foreseeable future and putting 
these prohibitions in place will help to prevent further degradation of 
habitat and decrease synergistic, negative effects from other ongoing 
or future threats.
    In particular, this proposed 4(d) rule would provide for the 
conservation of the Miami cave crayfish by prohibiting the following 
activities, unless they fall within specific exceptions or are 
otherwise authorized or permitted: importing or exporting; take (as set 
forth at 50 CFR 17.21(c)(1) with exceptions as discussed below); 
possession and other acts with unlawfully taken specimens; delivering, 
receiving, carrying, transporting, or shipping in interstate or foreign 
commerce in the course of commercial activity; or selling or offering 
for sale in interstate or foreign commerce.
    Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, or collect, or to attempt to engage in any 
such conduct. Some of these provisions have been further defined in 
regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by 
direct and indirect impacts, intentionally or incidentally. Regulating 
take would help preserve the species' one population and decrease 
synergistic, negative effects from other ongoing or future threats. 
Therefore, we propose to prohibit take of the Miami cave crayfish, 
except for take resulting from those actions and activities 
specifically excepted by the 4(d) rule.
    Exceptions to the prohibition on take would include all of the 
general exceptions to the prohibition on take of endangered wildlife, 
as set forth in 50 CFR 17.21 and additional exceptions, as described 
below.
    The proposed 4(d) rule would also provide for the conservation of 
the species by allowing exceptions that incentivize conservation 
actions or that, while they may have some minimal level of take of the 
Miami cave crayfish, are not expected to rise to the level that would 
have a negative impact (i.e., would have only de minimis impacts) on 
the species' conservation. The proposed exceptions to these 
prohibitions include activities that will prevent further saltwater 
intrusion into the Biscayne Aquifer and water management activities 
that improve water quality or enhance natural infiltration into the 
Biscayne Aquifer:
    (1) Activities that will prevent further saltwater intrusion into 
the Biscayne Aquifer include coastal resiliency projects and canal 
maintenance or construction that prevent backflow of salt water, and
    (2) Water management activities or coastal wetland restoration 
projects that improve freshwater and estuarine habitats; improve 
salinity distribution and reestablish productive nursery habitat along 
the shoreline; restore the quantity, quality, timing, and distribution 
of freshwater to Biscayne Bay and Biscayne National Park; restore the 
spatial extent of natural coastal glades habitat; or enhance natural 
infiltration into the Biscayne Aquifer.
    Despite these prohibitions regarding threatened species, we may 
under certain circumstances issue permits to carry out one or more 
otherwise-prohibited activities, including those described above. The 
regulations that govern permits for threatened wildlife state that the 
Director may issue a permit authorizing any activity otherwise 
prohibited with regard to threatened species. These include permits 
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 (50 CFR 
17.32). 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 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 must 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, would be able to conduct 
activities designed to conserve the Miami cave crayfish that may result 
in otherwise prohibited take without additional authorization.

[[Page 64869]]

    Nothing in this proposed 4(d) rule would 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 our ability to 
enter into partnerships for the management and protection of the Miami 
cave crayfish. However, interagency cooperation may be further 
streamlined through planned programmatic consultations for the species 
between us and other Federal agencies, where appropriate. We ask the 
public, particularly State agencies and other interested stakeholders 
that may be affected by the proposed 4(d) rule, to provide comments and 
suggestions regarding additional guidance and methods that we could 
provide or use, respectively, to streamline the implementation of this 
proposed 4(d) rule (see Information Requested, above).

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.
    We have found critical habitat to be prudent and determinable for 
the Miami cave crayfish and have developed a proposed critical habitat 
rule for this species. On August 29, 2023, we were informed that the 
Office of Information and Regulatory Affairs (OIRA) in the Office of 
Management and Budget (OMB) determined that our proposed critical 
habitat rule is significant under Executive Order 12866. Therefore, we 
will publish a proposed critical habitat rule for the Miami cave 
crayfish following interagency review of the proposed critical habitat 
rule.

Required Determinations

Clarity of the Rule

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

National Environmental Policy Act (42 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), E.O. 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 Secretaries' 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.

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 Florida Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT).

Authors

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

List of Subjects in 50 CFR Part 17

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

Proposed Regulation Promulgation

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

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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

0
2. In Sec.  17.11, amend paragraph (h) by adding an entry for 
``Crayfish, Miami cave'' to the List of Endangered and Threatened 
Wildlife in alphabetical order under CRUSTACEANS to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

[[Page 64870]]



----------------------------------------------------------------------------------------------------------------
                                                                                              Listing citations
           Common name              Scientific name        Where listed          Status         and applicable
                                                                                                    rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
           Crustaceans
 
                                                  * * * * * * *
Crayfish, Miami cave............  Procambarus milleri  Wherever found.....               T   [Federal Register
                                                                                              citation when
                                                                                              published as a
                                                                                              final rule]; 50
                                                                                              CFR 17.46(e); \4d\
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

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


Sec.  17.46  Special rules--crustaceans.

* * * * *
    (e) Miami cave crish (Procambarus milleri).
    (1) Prohibitions. The following prohibitions that apply to 
endangered wildlife also apply to the Miami cave crayfish. Except as 
provided under paragraph (e)(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.
    (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 a commercial 
activity, as set forth at Sec.  17.21(e) for endangered wildlife.
    (v) Sale or offer for sale, as set forth at Sec.  17.21(f) for 
endangered wildlife.
    (2) Exceptions from prohibitions. In regard to this species, you 
may:
    (i) Conduct activities as authorized by a permit under Sec.  17.32.
    (ii) Take, as set forth at Sec.  17.21(c)(2) through (4) for 
endangered wildlife.
    (iii) Take, as set forth at Sec.  17.31(b).
    (iv) Possess and engage in other acts with unlawfully taken 
wildlife, as set forth at Sec.  17.21(d)(2) for endangered wildlife.
    (v) Take incidental to an otherwise lawful activity caused by:
    (A) Activities that will prevent further saltwater intrusion into 
the Biscayne Aquifer, such as coastal resiliency projects and canal 
maintenance or construction that prevent backflow of salt water; or
    (B) Water management activities or coastal wetland restoration 
projects that improve freshwater and estuarine habitats; improve 
salinity distribution and reestablish productive nursery habitat along 
the shoreline; restore the quantity, quality, timing, and distribution 
of freshwater to Biscayne Bay and Biscayne National Park; restore the 
spatial extent of natural coastal glades habitat; or enhance natural 
infiltration into the Biscayne Aquifer.

Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2023-20293 Filed 9-19-23; 8:45 am]
BILLING CODE 4333-15-P