This document and all comments received may be viewed online through the Federal eRulemaking portal at www.regulations.gov using the docket number listed above. Electronic retrieval help and guidelines are also available at www.regulations.gov. An electronic copy of this document may also be downloaded from the Office of the Federal Register's website at www.FederalRegister.gov and the Government Publishing Office's website at www.GovInfo.gov.

All comments received before the close of business on the comment closing date indicated above will be considered and will be available for examination in the docket at the above address. Comments received after the comment closing date will be filed in the docket and will be considered to the extent practicable. In addition to late comments, FHWA will also continue to file relevant information in the docket as it becomes available after the comment period closing date and interested persons should continue to examine the docket for new material. A final rule may be published at any time after the close of the comment period and after DOT has had the opportunity to review the comments submitted.

The principal mission of the DOT is to ensure America has the safest, most efficient, and modern transportation system in the world. This system boosts our economic productivity and global competitiveness and enhances the quality of life in communities both rural and urban. We depend on transportation for access to jobs, to enable us to conduct our business, to supply us with services and goods, and to facilitate our leisure and recreational activities. The Department's mission is accomplished through strategic goals pertaining to safety, economic strength and global competitiveness, equity, climate and sustainability, transformation, and organizational excellence.

An efficient and well-maintained roadway network is a critical component of our overall transportation system. Our roadway network must be continuously monitored and repaired to keep it functioning. Periodically, roadways must also be rehabilitated, reconstructed, or otherwise improved. The FHWA strongly encourages that work zones to accomplish these activities be implemented and maintained as safely as possible and with the least possible amount of travel disruption. Doing so directly supports the DOT safety strategic goal and facilitates the movement of people and goods while that work occurs, which is essential for maintaining economic strength and global competitiveness. Similarly, effective work zone management also ensures that impacts themselves do not unduly burden any one user group excessively without efforts to mitigate those differential impacts, which furthers the DOT equity strategic goal. Congestion generated by work zones contributes to vehicular pollution, and reducing congestion undoubtedly supports DOT goals pertaining to climate and sustainability. Finally, continuous development and support of new technologies, strategies, and uses of new sources of data for work zone management relate directly to the Department's transformation and organizational excellence goals.

This NPRM proposes changes to Subpart J, Work Zone Safety and Mobility, and Subpart K, Temporary Traffic Control Devices to clarify and correct certain aspects of the regulations that were last modified in 2004 and 2006, respectively.

Work zones are a necessary part of meeting the need to maintain and upgrade our aging roadway infrastructure. Work zone activities are expected to increase significantly with the passage of the Bipartisan Infrastructure Law (BIL) (enacted as the Infrastructure Investment and Jobs Act (Pub. L. 117-58) (November 15, 2021)). The law provides approximately $350 billion for Federal highway programs during Fiscal Years 2022 through 2026. 1 This represents a 55 percent increase in highway and bridge program funding over the Fixing America's Surface Transportation (FAST) Act (Pub. L. 114-94, December 4, 2015). 2

Even without increased funding, work zones already result in significant safety and mobility impacts. In 2020 (the latest year for which data are available), the National Highway Traffic Safety Administration (NHTSA) reports that 857 individuals lost their lives in 774 fatal work zone crashes. 3 In 2020, 117 workers at road construction sites experienced a fatal occupational injury, 62 of which involved a worker on foot being struck by a motor vehicle. 4

In terms of mobility impacts, it has been estimated that 10 percent of congestion in urban areas and 35 percent of congestion in rural areas is caused by work zones. 5 In Pennsylvania, 17 to 26 percent of congestion is attributed to roadwork;  6 in Florida, 4 to 7 percent of mid-day and p.m. peak congestion on arterial streets are attributed to work zones. 7 Certainly, the requirements contained in 23 CFR part 630 Subpart J continue to be needed to help manage and mitigate work zone safety and mobility impacts across the country.

The FHWA has developed multiple resources to assist States in implementing the revisions to the Work Zone Safety and Mobility Rule 2004. 8 9 10 11 12 Overall, States have complied with requirements to establish a work zone safety and mobility policy and to implement a process for identifying significant projects. However, the extent of implementation of some of the other required State-level processes and procedures has varied across the country. For example, many States have developed and implemented systematic procedures to assess anticipated work zone impacts in project development. However, only a few States have established procedures to monitor and manage actual safety and mobility impacts during project implementation or to perform post-project evaluations, despite increased availability of data sources and methodologies available to do so. 13 14 15 Similarly, many States have not fully embraced the opportunities for conducting data-driven performance-based work zone process reviews that these data sources and methodologies now offer, despite additional guidance and encouragement to do so. 16 17 The FHWA acknowledges that a lack of clarity in what is specifically required by certain parts of the regulation may partially explain the uneven adoption. The existing regulation has language that was considered necessary at the time it was established to ensure State understanding of the regulation, but which is now considered superfluous to its understanding and implementation.

In addition, FHWA recognizes that the required frequency of Agency work zone process reviews may be hampering some States from performing more in-depth assessments using available data and methods. Section 11302 of the BIL calls for revisions to § 630.1008(e) to ensure that the work zone process review is required not more frequently than once every 5 years. In addition, Section 11303 of the BIL calls for revisions to § 630.1010(c) to ensure that only a project with a lane closure for 3 or more consecutive days shall be considered to be a significant project for purposes of that section and, notwithstanding any other provision of law, a State shall not be required to develop or implement a transportation management plan (TMP) (as described in § 630.1012) for a highway project not on the Interstate System if the project requires not more than 3 consecutive days of lane closures.

These regulations were last modified in 2004 and introduced requirements for State departments of transportation to develop and adopt work zone safety policies; to conduct work zone impacts analyses during project development to better understand individual project characteristics and the associated work zone impacts; to develop TMPs for projects as determined by the State's policy and results of impact analysis; and provisions to allow States flexibility to choose either method-based or performance-based specifications for their contracts. The FHWA proposes to revise §§ 630.1004, 630.1006, 630.1008, 630.1010, 630.1012, 630.1014, and 630.1016 to clarify certain aspects of the regulation and to update and provide additional emphasis to certain elements that have not seen the quality of implementation that was initially envisioned. The following is a summary of key proposed changes:

• Incorporation of new definitions and clarification of some existing definitions;

• Incorporation of a requirement in a State's Work Zone Safety and Mobility Policy to define the safety and mobility performance measures that the State will monitor and report;

• Reframing the requirement for bi-annual work zone process reviews as work zone programmatic reviews to be performed every 5 years, along with additional information on what is to be included in such reviews;

• Revising the definition of what constitutes a “significant project”; and

• Simplifying the language describing the components of a TMP.

The proposed changes to this section include: defining terms not previously defined; strengthening the definitions of a few terms that were already included in this section; and improving the organization of the regulation.

The FHWA proposes to add definitions of the terms “Agency” and “State” to this section. The FHWA also proposes to modify the definition of “Mobility” in work zones to delete the language about not compromising the safety of highway workers, as the importance of not compromising the safety of highway workers is already emphasized in the definition of “Safety.” Next, the definition of “Safety” would be revised to remove superfluous language and to strengthen the language pertaining to highway workers by adding the rate of highway worker fatalities and injuries per hours of work activity as a useful performance measure of safety.

The FHWA also proposes to move the definition of “Transportation Management Plan” that had been a part of § 630.1012(b) to this Definitions section. This definition includes reference to the temporary traffic control (TTC) plan and a traffic operations (TO) component to the TMP, as needed. The description of a public information component has been expanded to public information and outreach (PIO) to be consistent with the intent of that aspect of the TMP. The definition of a “Work Zone Crash” would be revised to make it consistent with the definition of a work zone crash in the Model Minimum Uniform Crash Criteria (MMUCC). 18 The reference to the MMUCC would be updated to the 5th edition published in 2017, and superfluous language describing the development of the MMUCC would be removed.

The FHWA also proposes to revise the definition of “Work Zone Impacts” to better list the factors affecting work zone impacts, particularly factors that affect highway worker safety. Examples are provided of traffic and travel characteristics that influence such impacts (volume, speed, vehicle mix and classification, etc.). In addition, revisions to the definition are proposed to better describe that such impacts may extend upstream or downstream of the limits of the work zone in addition to other highway corridors, other modes of transportation, or the regional transportation network.

Finally, FHWA proposes to add a definition for “Work Zone Programmatic Reviews.” This definition would replace the term “Process Review” to better emphasize the intent of the review upon the State's overall work zone management program. The work zone programmatic review is a data driven, systematic, and holistic analysis that uses quantitative and qualitative data from different sources to assess the safety and mobility performance of work zones under an agency's jurisdiction in order to identify improvements to that agency's work zone processes and procedures.

A data-driven approach to work zone safety and mobility management requires the definition and use of performance measures. However, when originally published in 2004, the existing regulation did not require States to define the performance measures they would use to monitor and manage work zone impacts as well as their overall work zone management program. As a result, not all States have identified performance measures they plan to monitor, nor have they developed the processes and procedures necessary to compute such measures. Therefore, FHWA proposes to revise this section to add a requirement that the State's work zone safety and mobility policy will identify the safety and mobility performance measures that will be used to monitor and manage performance. The revision suggests the following project-level and programmatic-level performance measure examples: number of fatal and injury crashes occurring in a work zone (project-level measure); percent of projects that exceed a preestablished crash rate in the work zone (programmatic-level measure); number of highway worker fatalities and injuries experienced or highway worker fatality and injury rate per hours worked (project- or programmatic-level measure); percent of projects that experience queues above a predefined threshold (programmatic-level measure); and percent of time when speeds in a work zone drop below a predefined threshold (project-level measure).

When the existing regulation was published in 2004, the idea of work zone safety and mobility management was a new concept. Consequently, the language in the regulation was written to give States significant leeway in how they chose to establish work zone safety and mobility management policies and procedures. The FHWA believes that States have made significant strides in their assessment and management procedures over the past 15 years that the existing regulation has been in place. In addition, analytical tools and data sources are readily available to perform these assessments. Therefore, FHWA proposes to revise § 630.1008(b) on work zone assessment and management procedures to strengthen these requirements. The word “should” would be replaced with “shall” in the first sentence. Strengthening the requirement to perform these assessments and management efforts will facilitate continued improvement in work zone safety and mobility nationally without unduly burdening the States. Next, the word “potential” would be added before “work zone impacts” to further indicate that it is an activity that occurs during project development, and the phrase “to all road users and highway workers” would be added to emphasize the importance of assessing potential impacts to both groups during project development. Finally, the words “impacts occurring” would be added after the phrase “safety and mobility” to emphasize the importance of monitoring conditions that occur when a work zone is in place.

Similarly, regulatory language published in 2004 indicated the need to use data and other information to improve agency work zone safety and mobility management processes but did not provide a lot of specifics as to what data or information could or should be used. Thus, FHWA also proposes to revise § 630.1008(c) on work zone data. A description of safety surrogate data and of work zone exposure data would be added to the list of available data sources that States shall use to monitor and manage work zone impacts for specific projects during implementation and to perform its work zone programmatic reviews. Examples of operational information (speeds, travel times, queue length and duration, etc.) would also be added to this section.

The FHWA proposes to revise § 630.1008(e) to change the description of process reviews to work zone programmatic reviews. The change in terminology emphasizes the importance of the review to look at all aspects of a State's work zone management program. To comply with BIL, the frequency of work zone programmatic reviews is reduced from once every 2 years to once every 5 years. A statement would be added that the review will be shared with FHWA at the end of each 5-year review period.

The FHWA also proposes to strengthen the requirements of the work zone programmatic review with the addition of § 630.1008(e)(1) to indicate that it shall include a data-driven assessment of the safety and mobility performance of either all work zones occurring during the 5-year period of the review, or a representative sample of the State's significant work zones. The proposed regulation further states that the approach used for selecting the representative projects shall be documented in the review and based on factors such as land use, roadway type, type of work zone, and extent of the work zone impacts. Language is added which proposes that each programmatic review shall include an assessment of work zone safety and mobility performance occurring since the last review, systematic identification of the States' work zone management processes and procedures to be improved, action items to be taken to achieve improvement, divisions/offices responsible for implementing the actions, and the estimated timeline for implementation. Language is also added that would require States to monitor work zone performance annually and report that performance to FHWA at the end of the third year after the most recent programmatic review. Given the longer time that would now be allowed between reviews, this proposed requirement emphasizes the need to monitor work zones on a continuous basis rather than simply evaluating a sample of work zones at 5-year intervals.

The regulatory language published in 2004 indicated that appropriate personnel who represent the various stages of project development, and different offices within the State that are involved in work zone management, should participate in the process (now programmatic) review but did not explicitly call out agency functions and offices that should be involved in the review. Therefore, FHWA proposes to add § 630.1008(d)(2) to explicitly identify the various State divisions or offices that shall be examined as part of the programmatic review, including but not limited to project planning, design, project implementation, maintenance activities, transportation operations and management, permitting ( e.g., utilities, oversize/overweight, lane closures, sidewalk closures), training, and public information and outreach. The remaining language in this section would be revised as § 630.1008(e)(3). The FHWA proposes to add “and implementation” after “project development” to keep it consistent with the similar statement in § 630.1006. The FHWA also proposes to remove the last sentence of the remaining language in the existing version of this section since it simply describes the intent of process reviews and is not essential to the implementation of the regulation.

The FHWA proposes to revise § 630.1010(c) in response to directives included in BIL. Specifically, the paragraph would be changed to state that projects on the Interstate System within the boundary of a designated Transportation Management Area (TMA) that require intermittent or continuous lane closures for 3 or more consecutive days shall be considered significant projects.

The FHWA also proposes to add a new § 630.1010(d) to indicate that States shall not be required to develop or implement the TO or PIO components of a TMP for a highway project not on the Interstate System if the project is not deemed significant by the State. Although the existing language appeared to already allow this, this additional paragraph would emphasize that point more directly. This proposed addition would require that the previous paragraph (d) be renumbered as § 630.1010(e).

The FHWA proposes to revise § 630.1012(b) describing the TMP. The first full sentence would be moved to the § 630.1004 definitions and explanation of terms. The second sentence would be edited to utilize the TO and PIO acronyms previously defined § 630.1004.

The FHWA proposes to revise § 630.1012(b)(1) describing a TTC plan. The second sentence of this paragraph is superfluous to the intent of the regulation and would be deleted in its entirety. The American Association of State Highway and Transportation Officials (AASHTO) “Roadside Design Guide” that is incorporated by reference would be updated to the 2011 edition. This document was developed by AASHTO to present the concepts of roadside safety (including those in work zones) to designers so that the most practical, appropriate, and beneficial roadside design can be accomplished for each project.

Section 630.1012(b)(3) would be edited slightly to use the term “PIO” when discussing the public information and outreach component of a TMP when used.

The FHWA also proposes to delete §§ 630.1012(d)(1) and 630.1012(d)(2) from the regulation. Both paragraphs are informational only and are not needed.

The FHWA proposes that the compliance date be 12 months after publication of the final rule in the Federal Register . This would allow States time to implement the proposed changes in requirements. In addition, FHWA proposes to specify that the States' next work zone programmatic review would be due on December 31, 2025, and once every 5 years thereafter.

In 2007, at 72 FR 68489, FHWA added a new subpart K to 23 CFR part 630 to facilitate the appropriate use of, and expenditure of funds for, uniformed law enforcement officers, positive protective measures between workers and motorized traffic, and installation and maintenance of temporary traffic control devices during construction, utility, and maintenance operations. The intent of the regulation was to reduce both worker and motorist fatalities and injuries in work zones. Overall, work zone fatalities did decrease significantly during the latter half of that decade, from a high of 1,068 work zone fatalities in 2004 to 590 fatalities in 2011. 19 Unfortunately, since then that trend has reversed, growing from 590 fatalities in 2011 to 857 fatalities in 2020 (the most recent year of available national work zone fatality data).

Vehicle collisions with highway workers as a percentage of all highway worker fatalities have also been trending upward in recent years. In 2015, 35 percent of all highway worker fatalities at road construction sites were caused by a vehicle striking a worker; by 2020, that number has increased to 53 percent. 20 21

Among other provisions, the initial NPRM for Subpart K, published November 1, 2006, at 71 FR 64173, proposed that “. . . . positive protective measures shall be required to separate workers from motorized traffic in all work zones conducted under traffic in areas that offer workers no means of escape ( e.g., tunnels, bridges, etc.) unless an engineering analysis determines otherwise.”  22 The FHWA received a substantial number of comments to the NPRM. While overall the responses were supportive of the intent of the proposed rule, several of the respondents noted that the language imposed the requirements without any supporting research indicating that the proposed criteria were appropriate. 23 This created significant concerns with some respondents, who viewed the requirements as arbitrary and overly prescriptive. The FHWA, in response to the comments, acknowledged the lack of available data and research regarding vehicle intrusions, and modified the final rule language to require the need for longitudinal traffic barrier and other positive protection devices to be based on an engineering study. The final rule also required States to consider use of positive protection where such devices offer the highest potential for increased safety for workers and road users. The FHWA retained the conditions listed in the 2006 NPRM as examples of situations where positive protection use shall be considered and added roadside hazards such as drop-offs or unfished bridge decks that will remain overnight or longer as other examples.

Language in the Moving Ahead for Progress in the 21st Century Act (MAP-21) signed into law on July 6, 2012, directed FHWA to modify Subpart K to re-incorporate the original language proposed in the 2006 NPRM related to criteria for requiring positive protection. 24 However, research and data did not support the thresholds stated in the law. A study using the Roadside Safety Analysis Program (RSAP) and available data from New York State regarding work zone intrusion crash severities indicated that positive protection use in work zones could be justified using benefit-cost analyses in many cases, but on higher volume roadways and for longer duration projects than were specified in the law language. 25 26 The FHWA funded a separate benefit-cost analysis, using a different methodology, to evaluate the efficacy of modifying Subpart K language and also concluded that the thresholds for positive protection use stated in MAP-21 could not be justified. 27 Another study using an updated version of RSAP and updated cost values still resulted in recommendations for positive protection use in work zones that were higher than specified in the MAP-21 language. 28 Despite the lack of research findings supporting the criteria, reference to the MAP-21 language was retained in the Fixing America's Surface Transportation (FAST) Act, signed into law on December 4, 2015. 29

While the results of the various analyses have not supported the inclusion of the specific thresholds of the 2006 NPRM language into the Subpart K regulation, there is reason to revise the rule at this time. It has been over 15 years since the rule was first published. New technologies, such as work zone intelligent transportation systems (also referred to as smart work zones) and automated flagger assistance devices (AFADs), have become dependable tools that are now readily available to help mitigate the safety and mobility impacts of work zones and should be listed as options to consider within the regulation. Other advanced technologies to support connected and automated vehicle travel through and around work zones continue to be developed and deployed. Conversely, despite sufficient time to develop appropriate procedures to do so, adoption of the requirement to base decisions regarding the need for longitudinal traffic barriers and other positive protection devices on an “engineering study” have been uneven across the States. A need exists to strengthen the rule with regard to what constitutes an engineering study. Finally, the rule references guidelines and other documents that have been superseded by newer publications, and the rule needs to be revised to reflect the proper publication references.

Proposed revisions to § 630.1106(b) of the rule would specify that States are to perform an engineering study to guide decisions regarding the use of positive protection devices to prevent the intrusion of motorist traffic into the workspace and other potentially hazardous areas in the work zone, use of exposure control measures to avoid or minimize worker exposure to motorized traffic and road user exposure to work activities, and use of other traffic control measures. Therefore, FHWA proposes to add a definition of an engineering study to this section.

Next, NCHRP 350 has been superseded with the Manual of Assessing Safety Hardware (otherwise known as MASH), American Association of State Highway and Transportation Officials, AASHTO. The FHWA's longstanding policy is that all roadside safety hardware installed on the National Highway System (NHS) be crashworthy. As the MASH implementation process moves forward, there no longer is a need to call out the crashworthiness requirements that positive protection devices shall meet. Therefore, FHWA proposes that the text “. . . National Cooperative Highway Research Program (NCHRP) Report 350, Recommended Procedures for the Safety Performance Evaluation of Highway Features, 1993, Transportation Research Board, National Research Council” and subsequent language that incorporates by reference that report into the regulation be deleted.

The FHWA proposes to modify § 630.1106(b) to clarify that agency processes, procedures, or guidance regarding strategies and devices to be used for the management of work zone impacts, including the use of positive protection devices and other strategies, are to be based on an engineering study. In addition, new details are proposed to provide characteristics of an engineering study and examples of the types of engineering decisionmaking tools that could be used in the engineering study.

The FHWA also proposes to modify the text for paragraph (b)(2) from “Anticipated traffic speeds through the work zone” to “Anticipated operating conditions including traffic volume, vehicle mix, and speeds through the work zone.” Paragraph (b)(3) would then be modified from “Anticipated traffic volume” to “Anticipated traffic safety impacts,” paragraph (b)(4) would be deleted, and the remaining item list would be renumbered.

The FHWA proposes to modify § 630.1108(a), Positive Protection Devices, to remove redundant language indicating that decisions regarding the use of longitudinal traffic barrier and other positive protection devices shall be based on an engineering study, as this was already stated in § 630.1106(b). The FHWA also proposes that this section be revised to require positive protection devices be used in work zones with high anticipated operating speeds that provide workers no means of escape from motorized traffic intruding into the workspace unless an engineering study determines otherwise. This language is consistent with that initially proposed in the 2006 Subpart K NPRM and in MAP-21 for these situations. The remaining portion of this section would retain the existing language requiring positive protection devices to be considered in other situations that place workers at increased risk from motorized traffic, and where positive protection devices offer the highest potential for increased safety for workers and road users.

The FHWA proposes to modify the list of technologies and strategies in § 630.1108(c), Other Traffic Control Measures. Specifically, FHWA proposes that paragraph (c)(7) be modified to include the use of automated flagger assistance devices (AFADs) in addition to enhanced flagger station setups already mentioned. Paragraph (c)(16) would be modified from automated speed enforcement to speed safety cameras, which is the preferred title of the technology as an FHWA proven safety countermeasure. 30 Two additional technologies, protection vehicles and intelligent transportation systems (ITS) and other advanced technology solutions and strategies, are additionally proposed as paragraphs (c)(21) and (c)(22).

The FHWA proposes to revise the internet website addresses of the American Traffic Safety Services Association's (ATSSA) “Quality Guidelines for Work Zone Traffic Control Devices,” the Illinois Department of Transportation “Quality Standards for Work Zone Traffic Control Devices,” and the Minnesota Department of Transportation “Quality Standards—Methods to determine whether the various traffic control devices are Acceptable, Marginal, or Unacceptable.” These documents are currently available, but the website addresses have changed since subpart K was originally issued in 2007.

The FHWA is incorporating by reference the more current versions of the manuals listed herein. Specifically, FHWA incorporates by reference Chapter 9 of the AASHTO “Roadside Design Guide: Traffic Barriers, Traffic Control Devices, and other Safety Features for Work Zones” but will incorporate the 2011 edition instead of the 2002 edition. This document was developed by AASHTO to present the concepts of roadside safety (including those in work zones) to designers so that the most practical, appropriate, and beneficial roadside design can be accomplished for each project. In addition, FHWA incorporates by reference its 2009 “Manual on Uniform Traffic Control Devices for Streets and Highways,” including Revisions No. 1 and No. 2, dated May 2012, and No. 3 dated August 2022. This document was developed by FHWA to define the standards used by road managers nationwide to install and maintain traffic control devices on all public streets, highways, bikeways, and private roads open to public travel.

The documents that FHWA is incorporating by reference are reasonably available to interested parties, primarily State DOTs, local agencies, and Tribal governments carrying out Federal-aid highway projects. These documents represent the most recent refinements that professional organizations have formally accepted and are currently in use by the transportation industry. The documents incorporated by reference are available on the docket of this rulemaking and at the sources identified in the regulatory text below. The specific standards are discussed in greater detail elsewhere in this preamble.

The FHWA has considered the impacts of this rule under Executive Order (E.O.) 12866 (58 FR 51735, Oct. 4, 1993), Regulatory Planning and Review, as amended by E.O. 1314094 (“Modernizing Regulatory Review”), and DOT's regulatory policies and procedures. The Office of Information and Regulatory Affairs within the Office of Management and Budget (OMB) has determined that this rulemaking is not a significant regulatory action under section 3(f) of E.O. 12866. Accordingly, OMB has not reviewed it under that E.O.

It is anticipated that the proposed rule would not be economically significant for purposes of E.O. 12866. The proposed rule would not have an annual effect on the economy of $200 million or more. The proposed rule would not adversely affect in a material way the economy, any sector of the economy, productivity, competition, or jobs. In addition, the proposed changes would not interfere with any action taken or planned by another Agency and would not materially alter the budgetary impact of any entitlements, grants, user fees, or loan programs.

In compliance with the Regulatory Flexibility Act (Pub. L. 96-354, 5 U.S.C. 601-612), FHWA has evaluated the effects of this proposed rule on small entities and has determined that it is not anticipated to have a significant economic impact on a substantial number of small entities. This rule applies to all State and local highway agencies that use Federal-aid highway funding in the execution of their highway program. However, the proposed regulatory action would only directly impact State requirements regarding work zone programmatic reviews, and otherwise would clarify the characteristics of a significant project. State governments are not included in the definition of small entity set forth in 5 U.S.C. 601. Therefore, FHWA certifies that the proposed rule will not have a significant economic impact on a substantial number of small entities.

This proposed rule would not impose unfunded mandates as defined by the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4, 109 Stat. 48). This proposed rule would not result in the expenditure by State, local, and Tribal governments, in the aggregate, or by the private sector, of $168 million or more in any one year (2 U.S.C. 1532). In addition, the definition of “Federal Mandate” in the Unfunded Mandates Reform Act excludes financial assistance of the type in which State, local, or Tribal governments have authority to adjust their participation in the program in accordance with changes made in the program by the Federal Government. The Federal-aid highway program permits this type of flexibility.

This proposed rule has been analyzed in accordance with the principles and criteria contained in E.O. 13132, and FHWA has determined that this proposed rule would not have sufficient federalism implications to warrant the preparation of a federalism assessment. The FHWA also has determined that this proposed rule would not preempt any State law or State regulation or affect the States' ability to discharge traditional State governmental functions.

Under the Paperwork Reduction Act of 1995 (PRA) (44 U.S.C. 3501, et seq. ), Federal agencies must obtain approval from OMB for each collection of information they conduct, sponsor, or require through regulations. The FHWA has determined that the rule does not contain collection of information requirements for the purposes of the PRA.

The FHWA has analyzed this proposed rule pursuant to the National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 4321 et seq. ) and has determined that it is categorically excluded under 23 CFR 771.117(c)(20), which applies to the promulgation of rules, regulations, and directives. Categorically excluded actions meet the criteria for categorical exclusions under the Council on Environmental Quality regulations and under 23 CFR 771.117(a) and normally do not require any further NEPA approvals by FHWA. The FHWA does not anticipate any adverse environmental impacts from this proposed rule.

The FHWA has analyzed this proposed regulatory action in accordance with the principles and criteria contained in E.O. 13175, “Consultation and Coordination with Indian Tribal Governments.” The purpose of the proposed regulatory action is to improve motorist, worker, and other vulnerable road user safety and mobility on Federal-aid highway projects. The FHWA believes that the proposed action would not have substantial direct effects on one or more Indian Tribes, would not impose substantial direct compliance costs on Indian Tribal governments, and would not preempt Tribal law. Therefore, the funding and consultation requirements of E.O. 13175 do not apply and a Tribal summary impact statement is not required.

The E.O. 12898 requires that each Federal Agency make achieving environmental justice part of its mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minorities and low-income populations. The FHWA has determined that this proposed rule does not raise any environmental justice issues.

A RIN is assigned to each regulatory action listed in the Unified Agenda of Federal Regulations. The Regulatory Information Service Center publishes the Unified Agenda in April and October of each year. The RIN contained in the heading of this document can be used to cross reference this action with the Unified Agenda.

Issued under authority delegated in 49 CFR 1.81 and 1.85.

In consideration of the foregoing, FHWA proposes to amend Title 23, Code of Federal Regulations, part 630, as set forth below:

Background on Viticultural Areas TTB Authority

Section 105(e) of the Federal Alcohol Administration Act (FAA Act), 27 U.S.C. 205(e), authorizes the Secretary of the Treasury to prescribe regulations for the labeling of wine, distilled spirits, and malt beverages. The FAA Act provides that these regulations should, among other things, prohibit consumer deception and the use of misleading statements on labels and ensure that labels provide the consumer with adequate information as to the identity and quality of the product. The Alcohol and Tobacco Tax and Trade Bureau (TTB) administers the FAA Act pursuant to section 1111(d) of the Homeland Security Act of 2002, codified at 6 U.S.C. 531(d). In addition, the Secretary of the Treasury has delegated certain administrative and enforcement authorities to TTB through Treasury Order 120-01.

Part 4 of the TTB regulations (27 CFR part 4) authorizes TTB to establish definitive viticultural areas and regulate the use of their names as appellations of origin on wine labels and in wine advertisements. Part 9 of the TTB regulations (27 CFR part 9) sets forth standards for the preparation and submission of petitions for the establishment or modification of American viticultural areas (AVAs) and lists the approved AVAs.

Section 4.25(e)(1)(i) of the TTB regulations (27 CFR 4.25(e)(1)(i)) defines a viticultural area for American wine as a delimited grape-growing region having distinguishing features as described in part 9 of the regulations and, once approved, a name and a delineated boundary codified in part 9 of the regulations. These designations allow vintners and consumers to attribute a given quality, reputation, or other characteristic of a wine made from grapes grown in an area to the wine's geographic origin. The establishment of AVAs allows vintners to describe more accurately the origin of their wines to consumers and helps consumers to identify wines they may purchase. Establishment of an AVA is neither an approval nor an endorsement by TTB of the wine produced in that area.

Section 4.25(e)(2) of the TTB regulations (27 CFR 4.25(e)(2)) outlines the procedure for proposing an AVA and allows any interested party to petition TTB to establish a grape-growing region as an AVA. Section 9.12 of the TTB regulations (27 CFR 9.12) prescribes standards for petitions to establish or modify AVAs. Petitions to establish an AVA must include the following:

• Evidence that the area within the proposed AVA boundary is nationally or locally known by the AVA name specified in the petition;

• An explanation of the basis for defining the boundary of the proposed AVA;

• A narrative description of the features of the proposed AVA affecting viticulture, such as climate, geology, soils, physical features, and elevation, that make the proposed AVA distinctive and distinguish it from adjacent areas outside the proposed AVA;

• The appropriate United States Geological Survey (USGS) map(s) showing the location of the proposed AVA, with the boundary of the proposed AVA clearly drawn thereon; and

• A detailed narrative description of the proposed AVA boundary based on USGS map markings.

TTB received a petition from the Appalachian Region Wine Producers Association, proposing the establishment of the “Nine Lakes of East Tennessee” AVA. The proposed Nine Lakes of East Tennessee AVA is in Anderson, Blount, Campbell, Claiborne, Cocke, Grainger, Hamblen, Jefferson, Knox, Loudon, Monroe, Roane, Sevier, and Union Counties, in Tennessee. The proposed AVA contains approximately 4,064 square miles (2,601,390 acres), with 232 acres of planted vineyards spread throughout the proposed AVA. There are also 29 wineries within the proposed AVA. According to the petition, there is at least one vineyard in each of the counties within the proposed AVA and a winery in all but two of the counties, demonstrating that commercial viticulture and winemaking take place throughout the entire proposed AVA.

According to the petition, the distinguishing features of the proposed Nine Lakes of East Tennessee AVA include its geology, soils, topography, and climate. Unless otherwise noted, all information and data pertaining to the proposed AVA is from the petition and its supporting exhibits.

The petition states that the proposed Nine Lakes of East Tennessee AVA is located entirely within the watershed of the Tennessee River and its tributaries. Within the region of the proposed AVA are nine lakes formed when the Tennessee Valley Authority (TVA) dammed the rivers to resolve issues with flooding, reforestation, and electricity production. According to the petition, the region has also been historically known as the Great Valley of East Tennessee. However, the petitioners chose not to propose that name as the Great Valley encompasses a much larger region than the proposed AVA. Because the proposed AVA only includes the area around the nine lakes created by the TVA, the petitioners believe that the name “Nine Lakes of East Tennessee” is a more appropriate, succinct, and descriptive name for the proposed AVA.

The petition included evidence showing use of the “Nine Lakes of East Tennessee” name to describe the region of the proposed AVA. The petition contained a visitor's guide to eastern Tennessee titled “9 Lakes of East Tennessee.” A website called “Nine Lakes Wine Country” provides information on the vineyards and wineries of the proposed AVA, 1 and the annual “Nine Lakes Wine Festival” showcases wines made in the proposed AVA. 2 A tourism website for the region encourages visitors to “[e]xplore all the 9 Lakes of East Tennessee Region has to offer you.”  3 Another tourism website's page on pet-friendly activities in Tennessee notes, “The communities surrounding Norris Lake, Cherokee Lake, Melton Hill Lake, Douglas Lake, Watts Bar Lake, Fort Loudon Lake, Tellico Lake, and Chilhowee & Calderwood Lakes—dubbed the 9 Lakes region—is a dog-friendly area that welcomes furry friends.”  4 A 2021 Smoky Mountain Living Magazine article notes, “The 9 Lakes Region of East Tennessee is a road trip destination well known for its winding roads, mountain vistas, sparkling lakes, and beautiful waterfalls.”  5 The tourism website for the town of Farragut, Tennessee, located within the proposed AVA, features “The 9 Lakes Region” on its list of places to visit. 6 An advertisement for a Tennessee plumbing company urges water conservation in the home by noting, “Between the Mighty Mississippi on the west and the 9 Lakes Region on the east, Tennessee is rich in water resources.”  7 A 2019 USA Today story about tourism in Tennessee states that the “9 Lakes Region provide[s] scenic views . . . .”  8

According to the petition, Tennessee is divided into three main regions: East, Middle, and West. East Tennessee is further divided into three geographic regions—the Blue Ridge Mountains, the Valley and Ridge Province, and the Cumberland Plateau region. The proposed Nine Lakes of East Tennessee AVA is located entirely within the Valley and Ridge Province and includes all or portions of the 14 counties that surround the nine lakes formed by TVA dams along the Tennessee River. The proposed northern boundary is formed by the Tennessee-Virginia State line to exclude counties in Virginia, which are not associated with the name “Nine Lakes of East Tennessee.” The proposed northern boundary also includes a portion of the Cumberland Gap National Historical Park boundary and excludes the park from the proposed AVA. The proposed eastern and southeastern boundaries follow county lines, National Park boundaries, and National Forest boundaries to exclude the Cherokee National Forest and the Great Smoky Mountain National Park, which are not available for commercial viticulture due to their status as public lands. The proposed southwestern and western boundaries generally follow county lines to exclude portions of the counties that are associated with the Cumberland Plateau or Cumberland Escarpment, rather than the Valley and Ridge Province and the nine lakes of the Tennessee River.

The distinguishing features of the proposed Nine Lakes of East Tennessee AVA include its geology, soils, topography, and climate.

The geology of the proposed Nine Lakes of East Tennessee AVA consists almost entirely of sedimentary rocks initially deposited during the Paleozoic era, when an ocean covered much of eastern North America. The bedrock consists of alternating beds of limestone, dolomite, shale, and sandstone. As the Euro-African tectonic plate and the North American tectonic plate collided, the sediments and rock between them folded and fractured, resulting in the southwest-to-northeast orientation of the ridges and valleys within the proposed AVA. The petition states that this orientation of the ridges and valleys provides vineyard owners the ability to select locations with slope aspects which allow for first light on the vineyards to dry the heavy dew and thus help in disease prevention. Additionally, the slope aspects shade the vines from the evening sun and thus prevent excessive heat on the grape clusters.

The petition states that the geology to the north and south of the proposed AVA is similar to that of the proposed AVA, given that all three locations are within the Valley and Ridge Province. To the east of the proposed AVA is the Appalachian Mountain system, which is comprised of Lower Paleozoic limestone, dolomite, and shale with exposures of Precambrian igneous and metamorphic basement rocks such as tuff, rhyolite, granite, schist, and quartzite, as well as Precambrian sedimentary and metamorphic sandstone, conglomerate, arkose, and siltstone. To the west of the proposed AVA are the Cumberland Plateau and Cumberland Escarpment, which are the results of the continental collisions uplifting highly resistant caprock of Pennsylvanian age sandstone and conglomerate.

The soils of the proposed Nine Lakes of East Tennessee AVA are categorized in the Ultisols soil order. According to the petition, soils of this order are characterized as “strongly leached, acid forest soils with low native fertility” and have clay-enriched subsoil. Because of the acidity and low fertility of the soils, the petition states that timely application of fertilizer and lime in vineyards are important in maximizing grape yields. The depth of these soils ranges from shallow on the sandstone and shale ridges to very deep in the valleys and on large limestone formations. The soils have an udic soil moisture regime, meaning that the amount of stored moisture plus rainfall is approximately equal to or exceeds the amount of evapotranspiration. The soil temperature is predominantly thermic, meaning that at a depth of 20 inches, the soils have an average annual temperature of 59 to 72 degrees Fahrenheit (F).

To the north and south of the proposed AVA, the soils are similar, because all three regions are in the Valley and Ridge Province. To the east of the proposed AVA, in the Blue Ridge Mountains, soils are commonly well-drained and acidic and can be shallow to very deep. The primary soil order is Inceptisols (which lack significant clay accumulation in the subsoils) and, to a significantly lesser extent, Ultisols. The soils have an udic soil moisture regime, and the soil temperature regime is mesic (average annual soil temperature of 47 to 59 degrees F) or frigid (average annual soil temperature lower than 46.4 degrees F). West of the proposed AVA, in the Cumberland Plateau and Cumberland Escarpment, the main soil orders are Inceptisols and Ultisols with a thermic or mesic soil temperature regime and an udic soil moisture regime.

As previously discussed, the proposed Nine Lakes of East Tennessee AVA is within the Valley and Ridge geologic province and is characterized by very long linear valleys paralleled by ridges, all running northeast to southwest. Within the proposed AVA, elevations range between 1,100 to 1,500 feet in the ridges and 700 to 1,000 feet in the valleys. The Valley and Ridge Province continues to the north and south of the proposed AVA. However, the petition notes that elevations in the northern portion of the Valley and Ridge Province are higher than within the proposed AVA, and elevations in the southern portion of the province are lower. East of the proposed AVA are the Blue Ridge Mountains, with elevations between 1,000 and 6,643 feet. West of the proposed AVA is the Cumberland Plateau and Cumberland Escarpment, which have average elevations between 1,500 and 1,800 feet. According to the petition, the proposed AVA's location between higher elevations to the east and west have an effect on climate, which is discussed in more detail in the following section.

According to the petition, due to the influence of elevation, the proposed Nine Lakes of East Tennessee AVA is generally warmer than all surrounding regions except the region to the south. The petition states that, in general, temperatures decrease an average of three degrees F for every 1,000 feet in elevation, meaning that the higher-elevation regions to the north, east, and west of the proposed AVA can be expected to have generally cooler climates than the proposed AVA. The regions to the south and southwest of the proposed AVA, which have lower elevations, are generally warmer than the proposed AVA. The petition describes the proposed AVA's climate as “well-suited to growing a wide variety of wine grapes, including vinifera, hybrid, native, and muscadine varietals.” The petition notes that grape varietals grown in warm climates, like that of the proposed AVA, generally produce “bigger, bolder wines with higher alcohol, soft acidity, a fuller body, and more dark or lush fruit flavors.” By contrast, grapes grown in cooler climates often produce wines “that are more subtle with lower alcohol, crisp acidity, a lighter body, and typically bright fruit flavors.”

To support the climate claims, the petition includes data on the growing season length, average maximum and minimum temperatures, growing degree days (GDDs), 9 USDA plant hardiness zones, and precipitation amounts for the proposed AVA and each of the surrounding regions. The petition gathered data from 12 weather stations within the proposed AVA and 16 weather stations outside the proposed AVA. 10 The following tables, which were included in the petition, summarize the climate data for the locations within the proposed AVA and the surrounding regions.

On August 7, 2023 (88 FR 52084) we published a proposed rule announcing receipt of a program amendment from Montana. Montana submitted this proposed amendment to us, of its own volition, following the passage of Montana House Bill 576 (HB 756) during the 2023 legislative session. HB 576 amends the Montana Strip and Underground Mine Reclamation Act as well as section 82-4-203 and section 82-4-222 of MCA. HB 576 also adds four contingencies that apply to the proposed amendments. First, Montana proposes several changes to section 82-4-203(32), which defines and describes “Material Damage.” Next, Montana proposes to amend its coal mine operation permit requirements related to hydrologic information section 82-4-222(1)(m). Lastly, HB 576 adds four contingencies to the proposed amendments of section 82-4-203(32) and section 82-4-222(1)(m) that are not codified into the MCA but apply to the amended sections: a severability clause, a contingent voidness clause, an effective date clause, and a retroactive applicability clause.

By letter dated August 18, 2023 (FDMS Document ID No. OSM-2023-0007-0008), Multiple conservation groups sent us a letter requesting an extension of the public comment period. The conservation groups cited the controversial nature of the amendment, technical difficulties accessing the comment portal, and scheduling difficulties around a public holiday, as to why OSMRE should grant an extension on the comment period. OSMRE reviewed the request for an extension of the public comment period and agree that the controversial nature of the amendment affords the public more time to submit the fullest and most comprehensive comments possible. The full text of the program amendment is available for you to read at the locations listed above under ADDRESSES .

Under the provisions of 30 CFR 732.17(h), we are seeking your comments on whether the amendment satisfies the applicable program approval criteria of 30 CFR 732.15. If we approve the amendment, it will become part of the State program.

If you submit written or electronic comments on the proposed rule during the 15-day comment period, they should be specific, confined to issues pertinent to the proposed regulations, and explain the reason for any recommended change(s). We appreciate any and all comments, but those most useful and likely to influence decisions on the final regulations will be those that either involve personal experience or include citations to and analyses of SMCRA, its legislative history, its implementing regulations, case law, other pertinent State or Federal laws or regulations, technical literature, or other relevant publications.

We cannot ensure that comments received after the close of the comment period (see DATES ) or sent to an address other than those listed (see ADDRESSES ) will be included in the docket for this rulemaking and considered.

Before including your address, phone number, email address, or other personal identifying information in your comment, you should be aware that your entire comment including your personal identifying information, may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.

On August 7, 2023 (88 FR 52086) we published a proposed rule announcing receipt of a program amendment from Montana. Under section 1 of SB 392 Montana proposes to add a provision to MCA, section 1, for the equal application of court costs to the prevailing party in contested case proceedings by a court or administrative agency that issues a decision pursuant to § 82-4-2. This proposed section allows that a court or administrative agency may award the prevailing party reasonable costs of litigation, including filing fees, attorney fees, and witness costs. Under this proposal a court or administrative agency may not consider the identity of the party when awarding costs. The proposal applies equally to all parties in an action and places the burden of proof and persuasion for awarding court costs on the requesting party. SB 392 does not state where section 1 will be codified in the MCA. This will be done by the legislature later; however, section 1 will be an integral part of the MCA.

The proposal amends § 82-4-251(7) and § 82-4-252(5) to reference the equal application of court costs in section 1. § 82-4-251(7), which discusses the awarding of court costs.

Lastly, SB 392 adds four contingencies to section 1 and the proposed amendments to § 82-4-251 and § 82-4-252. The contingencies will not be codified into the MCA but apply to section 1 as proposed and the amended sections of the MCA. Section 4 of SB 392 contains codification instructions which state that [section 1] is intended to be codified as an integral part of § 82-4-2 and the provisions of § 82-4-2 apply to [section 1]. Section 5 is a severability clause and states that if a part of SB 392 is found to be invalid, any part(s) found valid will remain in effect. Section 6 of SB 392 is an effective date, which states that the act is effective on passage and approval. Lastly, section 7 of SB 392 is an applicability clause, which states that SB 392 applies to court actions filed on or after the effective date of SB 392.

By letter dated August 18, 2023 (FDMS Document ID No. OSM-2023-0008-0008), multiple conservation groups sent us a letter requesting an extension of the public comment period. The conservation groups cited the controversial nature of the amendment, technical difficulties accessing the comment page, and scheduling difficulties around a Public Holiday, as reasons why OSMRE should grant an extension on the comment period. OSMRE reviewed the request for an extension of the public comment period and agree that the controversial nature of the amendment affords the public more time to submit the fullest and most comprehensive comments possible. The full text of the program amendment is available for you to read at the locations listed above under ADDRESSES .

Under the provisions of 30 CFR 732.17(h), we are seeking your comments on whether the amendment satisfies the applicable program approval criteria of 30 CFR 732.15. If we approve the amendment, it will become part of the State program.

If you submit written or electronic comments on the proposed rule during the 30-day comment period, they should be specific, confined to issues pertinent to the proposed regulations, and explain the reason for any recommended change(s). We appreciate any and all comments, but those most useful and likely to influence decisions on the final regulations will be those that either involve personal experience or include citations to and analyses of SMCRA, its legislative history, its implementing regulations, case law, other pertinent State or Federal laws or regulations, technical literature, or other relevant publications.

We cannot ensure that comments received after the close of the comment period (see DATES ) or sent to an address other than those listed (see ADDRESSES ) will be included in the docket for this rulemaking and considered.

Before including your address, phone number, email address, or other personal identifying information in your comment, you should be aware that your entire comment including your personal identifying information, may be made publicly available at any time. While you can ask us in your comment to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.

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.

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 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.

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).

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.

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

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.

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.

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.

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.

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.

In this discussion, we review the biological condition of the species and its resources, and the threats that influence the species' current and future condition, in order to assess the species' overall viability and the risks to that viability.

The 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:

• Sufficient freshwater quality and availability to support a suitable aquatic environment for movement and healthy individuals.

• 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).

• 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.

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. For full descriptions of all threats and how they impact the Miami cave crayfish, please see the SSA report (Service 2022, pp. 27-78).

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 (Veselý 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.

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 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.

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.

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.

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.

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.

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.

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.

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).

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.

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 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).

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 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.

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):

• 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.

• 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.

• 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.

• Clean Water Act of 1972 (33 U.S.C. 1251 et seq. ): indirectly benefits groundwater quality by protecting the quality of surficial waters.

• 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.

• The Grizzle-Figg Statute (Section 403.086, F.S.): outlines requirements for safe sewage disposal facilities and treatment of discharges from these sewage facilities.

• 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.

• 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.

• 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).

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.

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- 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.

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.

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.

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.

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 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 ).

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 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)).

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.

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).

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.

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.

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)).

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.

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 ).

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.

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

Under section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq. ), we are required to make a finding on whether or not a petitioned action is warranted within 12 months after receiving any petition that we have determined contains substantial scientific or commercial information indicating that the petitioned action may be warranted (hereafter a “12-month finding”). We must make a finding that the petitioned action is: (1) Not warranted; (2) warranted; or (3) warranted but precluded by other listing activity. We must publish a notification of these 12-month findings in the Federal Register .

Section 4 of the Act (16 U.S.C. 1533) and the implementing regulations at part 424 of title 50 of the Code of Federal Regulations (50 CFR part 424) set forth procedures for adding species to, removing species from, or reclassifying species on the Lists of Endangered and Threatened Wildlife and Plants (Lists). The Act defines “species” as including any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 1532(16)). The Act defines “endangered species” as any species that is in danger of extinction throughout all or a significant portion of its range (16 U.S.C. 1532(6)), and “threatened species” as any species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range (16 U.S.C. 1532(20)). Under section 4(a)(1) of the Act, a species may be determined to be an endangered species or a threatened species because of any of the following 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.

These factors represent broad categories of natural or human-caused actions or conditions that could have an effect on a species' continued existence. In evaluating these actions and conditions, we look for those that may have a negative effect on individuals of the species, as well as other actions or conditions that may ameliorate any negative effects or may have positive effects.

We use the term “threat” to refer in general to actions or conditions that are known to or are reasonably likely to negatively affect individuals of a species. The term “threat” includes actions or conditions that have a direct impact on individuals (direct impacts), as well as those that affect individuals through alteration of their habitat or required resources (stressors). The term “threat” may encompass—either together or separately—the source of the action or condition or the action or condition itself. However, the mere identification of any threat(s) does not necessarily mean that the species meets the statutory definition of an “endangered species” or a “threatened species.” In determining whether a species meets either definition, we must evaluate all identified threats by considering the expected response by the species, and the effects of the threats—in light of those actions and conditions that will ameliorate the threats—on an individual, population, and species 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 Act's definition of an “endangered species” or a “threatened species” only after conducting this cumulative analysis and describing the expected effect on the species now and in the foreseeable future.

The Act does not define the term “foreseeable future,” which appears in the statutory definition of “threatened species.” Our implementing regulations at 50 CFR 424.11(d) set forth a framework for evaluating the foreseeable future on a case-by-case basis. The term “foreseeable future” extends only so far into the future as we can reasonably determine that both the future threats and the species' responses to those threats are likely. In other words, the foreseeable future is the period of time in which we can make reliable predictions. “Reliable” does not mean “certain”; it means sufficient to provide a reasonable degree of confidence in the prediction. Thus, a prediction is reliable if it is reasonable to depend on it when making decisions.

It is not always possible or necessary to define 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' responses to those threats in view of its life-history characteristics. Data that are typically relevant to assessing the species' biological response include species-specific factors such as lifespan, reproductive rates or productivity, certain behaviors, and other demographic factors.

In conducting our evaluation of the five factors provided in section 4(a)(1) of the Act to determine whether the Cascades frog, plains spotted skunk, sicklefin chub, southern sea otter, sturgeon chub, Tennessee cave salamander, and Yazoo crayfish meet the Act's definition of “endangered species” or “threatened species,” we considered and thoroughly evaluated the best scientific and commercial information available regarding the past, present, and future stressors and threats. We reviewed the petitions, information available in our files, and other available published and unpublished information for all these species. Our evaluation may include information from recognized experts; Federal, State, and Tribal governments; academic institutions; foreign governments; private entities; and other members of the public.

In accordance with the regulations at 50 CFR 424.14(h)(2)(i), this document announces the not-warranted findings on petitions to delist one species and list six species. We have also elected to include brief summaries of the analyses on which these findings are based. We provide the full analyses, including the reasons and data on which the findings are based, in the decisional file for each of the seven actions included in this document. The following is a description of the documents containing these analyses:

The species assessment forms for Cascades frog, plains spotted skunk, sicklefin chub, sturgeon chub, Tennessee cave salamander, and Yazoo crayfish contain more detailed biological information, a thorough analysis of the listing factors, a list of literature cited, and an explanation of why we determined that each species does not meet the Act's definition of an “endangered species” or a “threatened species.” The species assessment form for the southern sea otter contains more detailed biological information, a thorough analysis of the listing factors, a list of literature cited, and an explanation of why we determined that the species continues to meet the Act's definition of a “threatened” species. To inform our status reviews, we completed species status assessment (SSA) reports for the Cascades frog, plains spotted skunk, sicklefin chub, southern sea otter, sturgeon chub, Tennessee cave salamander, and Yazoo crayfish. Each SSA report contains a thorough review of the taxonomy, life history, ecology, current status, and projected future status for each species. This supporting information can be found on the internet at https://www.regulations.gov under the appropriate docket number (see ADDRESSES , above).

On July 11, 2012, we received a petition from the Center for Biological Diversity to list 53 amphibian and reptile species, including Cascades frog ( Rana cascadae ), as an endangered or threatened species under the Act. On July 1, 2015, we published a 90-day finding (80 FR 37568) that the petition contained substantial information indicating listing may be warranted for the species. This document constitutes our 12-month finding on the July 11, 2012, petition to list Cascades frog under the Act.

The Cascades frog is a medium-sized frog typically less than 71 millimeters (mm) (2.8 inches (in)) in length; males are smaller than females. The Cascades frog is greenish brown with variation among frogs in spot appearance. The species is generally associated with middle to high elevations (approximately 400 to 2,500 meters (m) (1,312 to 8,202 feet (ft)); its current and historical range extends along the Cascade Mountain Range from near the United States-Canada border south through Washington and Oregon to California just south of Lassen Peak. The species can also be found within the Klamath Mountains of California and the Olympic Mountains in Washington. The species may be extirpated within Lassen Volcanic National Park.

The Cascades frog is primarily aquatic, using lakes, ponds, wet meadows, and streams, where they are often found along shorelines or on emergent rocks or logs. It uses habitats that are maintained by cold winters with deep snowpack and spring snowmelt. A diversity of aquatic features is needed to support all life stages, breeding, foraging, and dispersal, and to provide areas of refuge from predators. Precipitation is important in supporting aquatic habitats and movement of individuals across the landscape. The Cascades frog overwinters in aerobic sediments at the bottom of aquatic features that have stable thermal conditions and do not completely freeze over.

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the Cascades frog, and we evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The primary threats affecting the Cascades frog's biological status include climate change, the chytrid fungus Batrachochytrium dendrobatidis ( Bd ), and nonnative trout.

We separated the species' range into five representative units (Olympics, Washington Cascades, Oregon Cascades, California North, and California South) to analyze current and future condition. Our current condition analysis finds that resiliency of the Cascades frog is variable across the range, with all representative units having conditions to support healthy populations. However, the California units are less resilient than those in Oregon and Washington. The distribution of healthy ( i.e., good to fair resiliency) populations of the species across a broad geographic range ensures that catastrophic events such as volcanic eruptions, presence of Bd, and wildfire are not likely to cause risk of Cascades frog extinction. Further, the Cascades frog continues to occupy historical sites throughout all representative units, and factors such as habitat, distribution of occurrences, connectivity, and natural geological and elevational gaps in the range all contribute to the species' overall adaptive capacity. Therefore, we conclude that Cascades frog is not currently in danger of extinction throughout all of its range and does not meet the Act's definition of an endangered species.

In considering the foreseeable future as it relates to the status of the Cascades frog, we considered the relevant risk factors (threats/stressors) acting on the species and whether we could draw reliable predictions about the species' response to these factors. Our analysis in the SSA report of future scenarios over a an approximately 50-year timeframe encompasses the best available information for future projections of habitat suitability based on maximum temperature, minimum temperature, precipitation, snow water equivalent, soil moisture, and potential evapotranspiration under two different climate change futures (representative concentration pathways (RCP) 4.5 and 8.5). We determined that this approximately 50-year timeframe enabled us to consider the threats/stressors acting on the species and draw reliable predictions about the species' response to these factors.

Based on the 3Rs (resiliency, representation, and redundancy) analyzed in the SSA report, the Cascades frog is projected to maintain multiple resilient populations, based on adequate suitable habitat availability, across the landscape for approximately 50 years into the future. The species is expected to withstand both stochastic and catastrophic events and have sufficient adaptive capacity to endure future climate change. Thus, after assessing the best available information, we conclude that Cascades frog is not likely to become endangered within the foreseeable future throughout all of its range.

Having determined that the Cascades frog is not in danger of extinction or likely to become so in the foreseeable future throughout all of its range, we considered whether it may be in danger of extinction or likely to become so in the foreseeable future in a significant portion of its range—that is, whether there is any portion of the species' range for which it is true that both (1) the portion is significant; and (2) the species is in danger of extinction now or likely to become so in the foreseeable future in that portion. Depending on the case, it might be more efficient for us to address the “significance” question or the “status” question first. We can choose to address either question first. Regardless of which question we address first, if we reach a negative answer with respect to the first question that we address, we do not need to evaluate the other question for that portion of the species' range.

We identified the Olympics and California South representative units as portions that might have a different status than the species rangewide. We examined the following threats: climate change, Bd, and nonnative trout, including cumulative effects.

The Olympics representative unit has fewer analysis units (AUs) (6) than most of the other representative units. However, the largest AU (unit 15) comprises nearly the entire Olympics representative unit and contains the majority of the Cascades frogs in that unit. Currently, this representative unit has populations with sufficient resiliency to withstand stochastic events, and the well-distributed largest population, which can be found across nearly the entire representation unit with good resiliency, is likely to withstand catastrophic events. We, therefore, determine that the Cascades frog is not in danger of extinction in the Olympics part of the range.

The Olympics have more snow-fed aquatic systems, indicating that they could be more sensitive to climate change impacts than habitat in other parts of the Cascades frog's range. However, these climate effects depend on the kind of wetland habitat affected, the distribution of wetland types, and the degree of change in hydrologic patterns under different future climates. We do not know explicit linkages of climate effects to specific Cascades frog habitat. Despite this caveat, our future conditions analysis indicates that the largest AU (unit 15), which covers the majority of the representation unit, will maintain fair habitat suitability across all future scenarios. Further, there does not appear to be widespread adult mortality consistent with Bd in the Olympics. While nonnative trout are in wetlands of the Washington Olympics and will likely continue to be a stressor, there are areas within the Olympics range ( e.g., national parks) where this stressor is not likely to exacerbate any projected declines. Based on the projected future conditions, we conclude that the Cascades frog is not in danger of extinction within the foreseeable future in the Olympics portion of its range.

Populations within the California South representative unit have experienced declines, local extirpations, and low population viability due in part to Bd, droughts, nonnative trout stocking, and lack of connectivity to other habitat. Despite declines in the California South part of the range, 75 percent of the AUs are currently in fair condition, indicative of relatively healthy populations. These fair condition AUs are distributed throughout the representative unit, thus providing redundancy to both stochastic and catastrophic events. We, therefore, determine that the Cascades frog is not in danger of extinction in the California South part of the range.

Our future conditions analysis shows that all AUs within the California South representation unit either maintain fair habitat condition or improve to good habitat condition approximately 50 years into the future. Although habitat suitability is predicted to increase, the potential for the Cascades frog to colonize suitable habitat is dependent on the health of source populations, connectivity, and habitat features to support the species across all life stages, and there is some uncertainty as to the extent that this could happen in the future. The projected future distribution of fair/good condition AUs throughout the California South unit provide redundancy to stochastic and catastrophic events. Based on this assessment, we conclude that the Cascades frog is not in danger of extinction within the foreseeable future in the California South portion of its range.

Because we determined that there are no portions within the species range that are currently in danger of extinction or likely to become so in the foreseeable future, we do not need to consider whether any portion of the range is significant. Nonetheless, we did undertake this further step for California South as a part of our evaluation of significant portion of the range. Considerations for significance can include whether the portion constitutes a large geographic area relative to the rest of the range, whether the portion constitutes habitat of high quality relative to the remaining portions of the range, or whether the portion constitutes high or unique value habitat for the species. California South is not a large representative unit relative to the rest of the range. It does not have unique or high value habitat nor high quality habitat relative to any other habitat throughout the range, and while the Lassen Mountains are different from other mountains in the range, they provide similar habitat features for the frogs, and thus they do not result in a meaningful difference in the ecology of the species. For these reasons, the California South portion is not considered significant. Therefore, the California South portion is not a significant portion of the range.

Thus, after assessing the best available information, we conclude that the Cascades frog is not in danger of extinction or likely to become in danger of extinction within the foreseeable future throughout all of its range or in any significant portion of its range. Therefore, we find that listing the Cascades frog as an endangered species or threatened species under the Act is not warranted.

A detailed discussion of the basis for this finding can be found in the Cascades frog species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R1-ES-2023-0127 (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo on the Peer Review Process, we solicited independent scientific reviews of the information contained in the Cascades frog SSA report. The Service sent the SSA report to three independent peer reviewers and received two responses. Results of this structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this finding.

On July 18, 2011, we received a petition from Mr. David Wade and Dr. Thomas Alton, requesting that multiple grassland thicket species or subspecies be listed as endangered or threatened under the Act, including the plains spotted skunk ( Spilogale interrupta, formerly recognized as one of three subspecies of eastern spotted skunk ( Spilogale putorius interrupta )). On December 4, 2012, we published a 90-day finding in the Federal Register (77 FR 71759) concluding that the petition presented substantial scientific or commercial information indicating that listing the plains spotted skunk may be warranted. This document constitutes our 12-month finding on the July 18, 2011, petition to list the plains spotted skunk under the Act.

The plains spotted skunk is a small mammal in the weasel family, most notable for its vivid black and white fur markings, that occurs in a wide range of habitat types across the Great Plains region of the contiguous United States. States with current occurrences (observed from 2000 to the present) include Arkansas, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Texas, and Wyoming.

This generalist species exhibits relatively high adaptability related to its diet and foraging, habitat use, and activity patterns. The habitat elements that we identified as important to plains spotted skunk individuals at each life stage include freshwater of sufficient quantity, food availability, den availability, and habitat complexity that provides protective cover. Plains spotted skunks are opportunistic omnivores, whose diet varies across seasons and habitats along with the availability and abundance of food items. Adult plains spotted skunks are typically solitary with the exception of mating pairs, females with dependent young, and adults denning during cold weather for thermoregulation. Despite their solitary nature, plains spotted skunks show no signs of territoriality.

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the plains spotted skunk, and we evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The primary threats affecting the plains spotted skunk's biological status include habitat loss and fragmentation due to agricultural and urban development, and climate change. Impacts from climate change include exacerbation of drought conditions and a decrease of available habitat along the Gulf Coast due to sea level rise. We also examined a number of other factors, including infectious pathogens, pesticides, invasive species, predation, competition, overexploitation, human-wildlife conflict, and direct mortality from other sources, but these factors did not rise to such a level that affected the species as a whole.

To assess the current condition of plains spotted skunks we analyzed one demographic factor (percent of counties with current location) and two habitat factors (habitat availability and freshwater availability) across six population analysis units that cover the current range of the species. The analysis units cover an extensive range with a wide diversity of habitats distributed across diverse environmental conditions. All analysis units had high habitat availability and at least moderate freshwater availability. The demographic factor scores ranged from low (two units) to moderate (four units). Largely due to their extensive range, plains spotted skunks have a high redundancy and are at a low risk for experiencing rangewide negative impacts from a catastrophic event at a given point in time. Similarly, the species demonstrates great adaptive capacity to adjust to environmental change and, thus, currently exhibits high representation.

We evaluated two scenarios to characterize the full range of uncertainty regarding plausible futures for the plains spotted skunk within a 30-year timeframe. Resiliency of the six analysis units was assessed under each scenario. Scenario 1 assumes intermediate to low sea level rise, RCP 4.5 emissions, and land use changes at 2050 from urbanization and agriculture. Scenario 2 assumes high sea level rise, RCP 8.5 emissions, and the same land use change projections as scenario 1. Considering both scenarios, we projected the effect of the scenarios on two habitat factors important to resiliency in the future: habitat availability and freshwater availability. Under both future scenarios, we projected some reduction in freshwater availability across the range. Under scenario 1, we projected one unit scoring low (unit 1) for freshwater availability, four scoring moderate (units 2-5), and one unit remaining high (unit 6). Under scenario 2, we projected two units scoring low for freshwater availability (units 1 and 3), one scoring moderate (unit 2), and three units remaining high (units 4-6). Under both scenarios, we projected only minimal reduction in current habitat availability across the range. Under both scenarios, we project climate-induced expansion of plains spotted skunks into new habitats and regions, especially for analysis units 1, 2, and 3. For habitat availability under both scenarios, we project five units (units 1-5) to retain high habitat availability and one unit (unit 6) to have moderate habitat availability. This reduction from currently high habitat availability in unit 6 to moderate in the future is attributed to sea level rise on the Gulf Coast of Texas. In either future scenario, we expect most analysis units to have high to moderate resiliency in terms of the habitat factors important to the viability of the plains spotted skunk. Based on an evaluation of the plausible catastrophes likely to adversely impact plains spotted skunk populations in 2050, we predict the species will maintain high redundancy in both future scenarios. Similarly, our analyses of the species' adaptative capacity based on scenarios 1 and 2 support the likelihood that the species will continue to exhibit high representation 30 years into the future.

The plains spotted skunk is a generalist species that eats a wide variety of foods and lives in a wide variety of habitats across six analysis units that extend across many U.S. States. Current resiliency, redundancy, and representation are all ranked as moderate to high. Although there is low distribution in two analysis units, the species' resiliency overall is moderate to high. The species exhibits high redundancy, greatly reducing the potential for catastrophic events to impact the species at the population level, and the species' high representation indicates a high capacity to adapt to changing environments. There are no identified threats currently affecting the species' viability across its range. Based on this information, the plains spotted skunk is not in danger of extinction throughout all of its range.

The 3Rs analysis in the SSA report provides evidence that the 30-year outlook for the species' projected condition under two future scenarios is still moderate to high. For resiliency, there is almost no change in habitat availability except for analysis unit 6 (the smallest unit) due to sea level rise. Freshwater availability drops under both scenarios, but only two analysis units are projected to be in low condition, although one of those is analysis unit 3, the largest unit. No units ranked “extremely low” under any future scenarios. Redundancy and representation are projected to be in the moderate to high range under both future scenarios. Based on this analysis, the species is not likely to become endangered in the foreseeable future.

We also evaluated the range of the plains spotted skunk to determine if the species is in danger of extinction now or likely to become so within the foreseeable future in any significant portion of its range. Although there is currently low distribution in two analysis units, the habitat and freshwater availability in those units is high to moderate, and there are no barriers to movement or distribution (other than the Mississippi River on the eastern border of its range). No threats have been identified that are currently affecting any portion of the species' range. Two units are projected to be in low condition for freshwater availability in the future, and sea level rise is predicted to decrease habitat availability in another unit. However, we do not expect freshwater availability to be low enough to be limiting, and given the retention of high habitat availability, we expect these units to support the species in the foreseeable future, especially in light of the plains spotted skunk's high adaptive capacity. There are no geographic portions of the range in which the species is potentially endangered or threatened.

After assessing the best available information, we concluded that the plains spotted skunk is not in danger of extinction or likely to become in danger of extinction within the foreseeable future throughout all of its range or in any significant portion of its range. Therefore, we find that listing the plains spotted skunk as an endangered species or threatened species under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the plains spotted skunk species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R3-ES-2023-0128 (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo on the Peer Review Process, we solicited independent scientific reviews of the information contained in the plains spotted skunk SSA report. The Service sent the SSA report to four independent peer reviewers and received two responses. Results of this structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this finding.

On August 15, 2016, we received a petition dated August 11, 2016, from WildEarth Guardians requesting that the sturgeon chub ( Macrhybopsis gelida ) and sicklefin chub ( M. meeki ) be listed as endangered or threatened and that critical habitat be designated for these species under the Act. On December 20, 2017, we published a 90-day finding (82 FR 60362) that the petition contained substantial information indicating that listing may be warranted for these species. We were later challenged by WildEarth Guardians for our failure to complete a 12-month finding for these species. Based on this litigation, we are now required by a September 30, 2021, court order to submit our 12-month finding for these species to the Federal Register by September 30, 2023. This document constitutes our 12-month finding on the August 11, 2016, petition to list sturgeon chub and sicklefin chub under the Act.

The sturgeon chub is a small minnow adapted to benthic riverine habitats with a slender streamlined body that inhabits turbid mainstem sections of the Missouri River and Mississippi River and some of their tributaries. The species has a widespread distribution and currently occupies 53 percent of its historical range across 12 U.S. States.

The sicklefin chub is a small minnow that inhabits large, turbid rivers, including the mainstem Missouri and Mississippi Rivers. Like sturgeon chub, sicklefin chub have also evolved specific adaptations to turbid, riverine habitats. It is distinguished from the sturgeon chub by long, sickle-shaped pectoral fins and the absence of ridge-like projections on its scales. This species also has a widespread distribution and currently occupies 75 percent of its historical range across 13 U.S. States.

Sicklefin chub primarily utilize mainstem river habitats, whereas sturgeon chub utilize both mainstem river and tributary habitat in both the Missouri and Mississippi River basins. Populations of both species need large enough areas of connected riverine habitat to fulfill their life-history needs ( e.g., spawning, egg/larval drift distances, suitable water temperatures, feeding/sheltering habitat) and provide refugia from habitat-altering stochastic events ( e.g., extreme flows from intense, sustained drought or increased variability in precipitation). Eggs are spawned in the water column during the summer months and develop (mediated by water temperature) into larva. Larval chubs continue to drift in river currents and swim vertically in the water column with energy provided by the egg yolk sac. Length of unfragmented reaches needed for larval development varies and is dependent on water temperature, flow velocity, and habitat complexity, among other variables. If larvae drift into a reservoir or still water habitat before they become a horizontal swimmer, it is presumed they settle to the bottom and experience high mortality. Neither species occupies the large stretches of reservoir habitat produced by dams along the Missouri River system.

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the sturgeon chub and sicklefin chub, and we evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The past construction of mainstem Missouri River dams and associated reservoirs is the main threat that led to the largest reduction in habitat for both species. In the future, changes in stream discharge from climate change is the only threat identified that could potentially lead to population-level impacts. We also evaluated the effects of channel modification, water quality, tributary barriers, pollutants, impingement and entrainment, predation, and hybridization. These threats are likely impacting both species at an individual level and not occurring at a scope or scale that would impact entire populations of these species.

Both sturgeon and sicklefin chubs have high effective population sizes. Given the amount of habitat fragmentation that occurred historically, the presence of robust genetics and effective population estimates, despite the level of fragmentation, is indicative of highly resilient populations. Current occupancy and abundance information indicates that populations are in moderate to high condition. Furthermore, populations of both species currently occupy habitats with one or more stream fragments meeting or exceeding the minimum thresholds to meet life-history needs. Sturgeon and sicklefin chubs currently exhibit high resiliency in multiple populations spread throughout a large portion of their historical ranges, providing redundancy against potential catastrophic events. There are no identified threats currently affecting these species' viability across their ranges at a population level. Thus, after assessing the best available information, we conclude that the sturgeon and sicklefin chub are not in danger of extinction throughout all of their ranges.

When looking to the future, we have no indication that the construction of additional dams, the demolition of existing dams, or major differences in dam operations are likely to occur. Similarly, we have no information to indicate that any of the other potential stressors identified are going to change in the future at levels that would impact sturgeon and sicklefin chub populations. The primary stressor to these species in the future is the potential for habitat loss and degradation from climate change. In the future, we project populations of both species to be relatively unchanged from their highly resilient current condition. These populations largely occupy mainstem river habitat, which is not likely to experience significant impacts from the effects of climate change on stream discharge. Here, we predict effective population size, occupancy and abundance, and unfragmented stream length to remain largely stable in light of potential changes to stream discharge. After assessing the best available information, we conclude that the sturgeon and sicklefin chub are not likely to become endangered within the foreseeable future throughout all of their ranges.

We also evaluated the range of the sturgeon and sicklefin chub to determine if these species are in danger of extinction now or likely to become so within the foreseeable future in any portion of their ranges. For the sturgeon chub, we examined the following threats: Missouri River mainstem dams and reservoir operations, tributary barriers and habitat fragmentation, channel modifications, water quality, climate change, pollutants, impingement/entrainment, predation, and hybridization, including cumulative effects of the stressors. Except for climate change, these threats are ubiquitous across the range of the species and acting on the sturgeon chub more or less equally rangewide. Although the effect of climate change will impact the entire range of the species as well, the future impact of climate change on stream discharge may be more pronounced in the upper reaches of secondary tributary habitat in two sturgeon chub populations. These stream reaches are much smaller and as a result less buffered from future changes in stream discharge resulting from climate change than the much larger and more stable mainstem river reaches that this species inhabits. These are the only portions we identified as potentially having a difference in status than the rangewide status, and therefore worth considering further for the purposes of this analysis.

The secondary tributary habitats in the two sturgeon chub populations mentioned above that may be subject to higher impacts from climate change constitute approximately 348 stream km (216 mi) out of 5,455 km (3,390 mi) of currently occupied stream km, or approximately 6 percent of the occupied range. These areas are smaller in wetted area and overall stream discharge than the mainstem river sections occupied by this species, and as a result may experience larger climate related swings in stream discharge which could negatively impact chubs living in those sections. These areas may be used opportunistically by the species when conditions allow, but these areas offer nothing ecologically unique and are not required by the sturgeon chub for any particular point of their life history. The mainstem river sections in these populations contain more sturgeon chub individuals and contain all of the same habitat features needed to meet the species' needs, including sufficient unfragmented stream length for the sturgeon chub to complete their life cycle and maintain resilient populations into the future. Based on the small size of this portion relative to the rest of the range, and the lack of unique habitat features, we do not consider secondary tributary habitats to be significant for the purposes of this analysis.

For the sicklefin chub, we examined the following threats: Missouri River mainstem dams and reservoir operations, tributary barriers and habitat fragmentation, channel modifications, water quality, climate change, pollutants, impingement/entrainment, predation, and hybridization, including cumulative effects. These threats are ubiquitous across the range of the species and acting on the sicklefin chub more or less equally rangewide. There are no areas with disproportionate impacts on sicklefin chub from these threats. Both sicklefin chub populations are currently high in resiliency and expected to continue to be so into the future despite the potential impact of the threats considered. Neither of the two populations considered as portions on their own meets the definition of an endangered or threatened species. We found no biologically meaningful portion of the sicklefin chub's range where threats are impacting individuals differently from how they are affecting the species elsewhere in its range, or where the biological condition of the species differs from its condition elsewhere in its range such that the status of the species in that portion differs from its status in any other portion of the species' range. We found no portion of either species' range that was both significant and in danger of extinction now or likely to become so within the foreseeable future in that portion. Therefore, we find that these species are not in danger of extinction now or likely to become so within the foreseeable future in any significant portion of their ranges.

After assessing the best available information, we concluded that sturgeon chub and sicklefin chub are not in danger of extinction or likely to become in danger of extinction within the foreseeable future throughout all of their ranges or in any significant portion of their ranges. Therefore, we find that listing the sturgeon chub and sicklefin chub as endangered species or threatened species under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the sturgeon chub and sicklefin chub species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R6-ES-2023-0131 for the sturgeon chub and Docket No. FWS-R6-ES-2023-0130 for the sicklefin chub (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo on the Peer Review Process, we solicited appropriate and independent scientific reviews of the information contained in the sturgeon chub and sicklefin chub SSA report. The Service sent the SSA report to five independent peer reviewers and received three responses. Results of this structured peer review process can be found at https://www.regulations.gov gov. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for these findings.

On April 20, 2010, we received a petition from the Center for Biological Diversity, Alabama Rivers Alliance, Clinch Coalition, Dogwood Alliance, Gulf Restoration Network, Tennessee Forests Council, and West Virginia Highlands Conservancy to list 404 aquatic, riparian, and wetland species, including the Tennessee cave salamander ( Gyrinophilus palleucus ), as an endangered or threatened species under the Act. On September 27, 2011, we published a 90-day finding in the Federal Register (76 FR 59836) concluding that the petition presented substantial scientific or commercial information indicating that listing may be warranted. This document constitutes our 12-month finding on the April 20, 2010, petition to list the Tennessee cave salamander under the Act.

The Tennessee cave salamander is a large, obligate subterranean aquatic salamander that currently occurs in 89 caves in central and southern middle Tennessee, northern Alabama, and northwestern Georgia and one spring in Tennessee. Distribution of the Tennessee cave salamander has not changed significantly since its discovery in the mid-1940s and extirpation is only known from one site. Two historical sites were rediscovered with increased survey efforts in 2018.

Little information is available on many aspects of the Tennessee cave salamander's life history, including egg deposition sites, incubation, larval habitat and diet, and breeding behavior. The Tennessee cave salamander requires sufficient water quality and availability, low sediment load, suitable substrate and cover, and adequate food sources in a cave ecosystem. The extent of suitable habitat in occupied cave systems is not mapped, but the three-dimensional nature of the habitat includes extensive areas that cannot be accessed and surveyed.

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the Tennessee cave salamander and evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The primary threats affecting the Tennessee cave salamander's biological status include habitat destruction or modification ( e.g., groundwater pollution from a variety of sources, sedimentation, mining and quarrying, groundwater extraction, and cave disturbance), disease, and climate change as well as the cumulative effects of the various threats on the landscape. Of the known threats, habitat destruction or modification currently is the primary threat rangewide to the species' current and future viability. Impacts to the species' habitat rangewide are caused by groundwater pollution from contaminants, and sedimentation associated with urbanization, agriculture, and silviculture. Impacts to individuals and populations may occur as a result of mining and quarrying, human visitation, and disease. The best available information does not indicate that the influence of climate change alone on the species' current condition is significant, but the effects of climate change may act synergistically with other threats to exacerbate the effects of urbanization, drought, and water withdrawal, particularly in the future.

Although the Tennessee cave salamander is a cryptic species that occurs in relatively inaccessible subterranean habitat, the best available information indicates that the species is present in all 12 historically occupied AUs. The Tennessee cave salamander currently exhibits high resiliency in two AUs and moderate resiliency in eight AUs. The two AUs in high resiliency make up the stronghold of the species' range. The two low resiliency AUs occur on the periphery of the species' range, and each is characterized by relatively few sites with species occurrence. Approximately 33 percent of known sites and over 50 percent of sites in the two AUs that make up the stronghold of the range occur on protected lands that confer some degree of protection to the species from threats caused by land use. Representation and redundancy have not declined from historical levels and are sufficient to support current Tennessee cave salamander viability. Overall, no threat is acting to an extent or severity such that the Tennessee cave salamander is at risk of extinction throughout its range.

The Tennessee cave salamander is expected to remain extant in all 12 AUs in all future scenarios. Our future condition analysis projected slight declines or declines in resiliency in one to nine AUs depending on the scenario and time step. There are minor projected increases in some threats that may affect the availability of suitable habitat across the species' range. We expect the loss of forest cover to have a negative impact on the habitat conditions for the species, but there is limited information quantitatively linking changes in forest cover surface condition and cave environments in the species' range. The species' response to projected changes also has not been observed or quantified.

In the future, the impacts under scenario 1 (status quo minimum) projected very minor changes to resiliency with only a slight decrease in one unit in 2040 and three units in 2060. Under scenario 2 (status quo maximum), with incorporation of a greater magnitude of forest loss, nine AUs are projected to exhibit no change in resiliency while only two units are projected to decrease by 2060 (only one unit by 2040). Under scenario 3 (increased impacts scenario), the magnitude of impact is greatest, with 5 of 12 AUs projected to exhibit decreased resiliency in both 2040 and 2060. Nevertheless, even in the greatest impact scenario, 6 of 12 AUs are projected to exhibit moderate or high resiliency. The resiliency of the two AUs that make up the stronghold of the range is not projected to change under any scenario and time step. No analysis unit-level extirpations are projected. Although representation and redundancy are projected to decline as a function of resiliency decreases under some scenarios and time steps, the species maintains sufficient adaptive capacity and ability to withstand catastrophic events to support future viability.

Although threats are similar throughout the range of the species, some local sites may be more affected by specific threats. For example, the species' response to threats is more pronounced in the Lower Tennessee and Lower Elk AUs. These AUs currently exhibit low resiliency driven primarily by low abundance, a lower degree of forest, and a higher degree of agricultural land use surrounding the low number of known sites in each AU (three sites in the Lower Tennessee and one site in the Lower Elk). Given the species' condition within the Lower Tennessee and Lower Elk AUs, we have identified the two units on the periphery of the species' range as areas that may be in danger of extinction now or within the foreseeable future due to the low current resiliency. Both AUs are projected to decline in resiliency in the future.

We then proceeded to the question of significance, asking whether the Lower Tennessee or Lower Elk AU meets the current understanding of significance. Although the Lower Tennessee and Lower Elk AUs contribute to the overall species-level representation and redundancy, the two AUs do not contain any high quality or high value habitat or any habitat or resources unique to the area and necessary to the Tennessee cave salamander's life history. In addition, the AUs encompass a low number of known sites with species' occurrences and do not make up a large geographic area of the species' range or contain a high proportion of its habitat or populations. Accordingly, we do not find the Lower Tennessee or Lower Elk AU, singly or collectively, to be a significant portion of the range.

After assessing the best available information, we conclude that the Tennessee cave salamander is not in danger of extinction or likely to become in danger of extinction within the foreseeable future throughout all of its range or in any significant portion of its range. Therefore, we find that listing the Tennessee cave salamander as an endangered species or threatened species under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the Tennessee cave salamander species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0133 (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memorandum on the Peer Review Process, we solicited independent scientific reviews of the information contained in the Tennessee cave salamander SSA report. The Service sent the SSA report to five independent peer reviewers and received four responses. Results of this structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this finding.

The Yazoo crayfish ( Faxonius hartfieldi, formerly Orconectes hartfieldi ) was included in a listing petition from the Center for Biological Diversity et al. (CBD 2010, pp. 792-793) in April 2010. The petition requested that the Service list 404 aquatic, riparian, and wetland species as endangered or threatened under the Act. In 2011, the Service found that this petition presented substantial scientific or commercial information indicating that listing may be warranted for the Yazoo crayfish (76 FR 59836; September 27, 2011). This document constitutes our 12-month finding on the April 2010 petition to list the Yazoo crayfish under the Act.

The Yazoo crayfish is a stream-dwelling species distributed among scattered locations in the Yazoo and Big Black River drainages in Mississippi. The species is small growing to 50 to 70 mm (2 to 3 in) in total length. Historically, the Yazoo crayfish was known from the Yazoo to the Big Black River drainage in Mississippi. The Yazoo crayfish currently occupies a wide range of stream sizes from small headwater streams such as the first order Little Mouse Creek (watershed area: 11 square kilometers (km 2 ) (4.25 square miles (m 2 ))) to large streams such as Fourteen mile Creek (watershed area: 644 km 2 (249 m 2 )). Occupied streams have moderate gradients and are located in the Lower and Upper Gulf Coastal Plain ecoregions.

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the Yazoo crayfish and evaluated all relevant factors under the five listing factors, including any regulatory mechanisms and conservation measures addressing these threats. The primary threat identified for the Yazoo crayfish is habitat fragmentation resulting from a number of factors such as stream channelization, sedimentation, road crossings, impoundments, and development. Other primary stressors affecting the species' biological status include regulated river flows, pollution, and climate change. Sedimentation in streams is often a result of within channel erosion of banks, head cutting, and stream incisement, which are usually the result of past land cover and land use practices ( e.g., channelization). Increased sedimentation from a variety of sources ( e.g., timber harvest that does not use best management practices, row crop agriculture, and urbanization) is detrimental to stream habitats for a variety of reasons.

Currently, the Yazoo crayfish occupies 12 analytical units across 20 hydrologic unit code (HUC)-12 watersheds in four HUC 8 watersheds and three level IV ecoregions. Five analytical units are considered to be high resiliency, three to be moderate resiliency, and four to be low resiliency. The highest resiliency analytical units are those with a higher number of occupied watersheds, lower channelization, lower fragmentation, and higher forest cover. In general, current land use practices do not appear to have an appreciable negative impact on the resiliency, redundancy, and representation. Moreover, habitat conditions for the species have been improving over the past 10-20 years (reduction in agriculture, increase in forested habitat within occupied watersheds, developed landcover has decreased). Lingering effects of prior land uses and management practices continue to impact the species, but there is evidence that streams are recovering from these land uses and habitat may be improving. Although threats are present on the landscape, the Yazoo crayfish has multiple moderate and high resilient populations distributed across the landscape, providing the species with adequate redundancy and representation. Therefore, the threats appear to have low imminence and magnitude such that they currently are not significantly affecting the species' viability. The SSA report describes some of the uncertainties in the species' occurrence, populations, and response to threats; however, considering the available data, the risk of extinction is low due to the distribution of multiple high and moderate resiliency units across the species' range. Thus, after assessing the best available information, we conclude that the Yazoo crayfish is not in danger of extinction throughout all of its range.

Land use patterns are projected to continue over the next 30 years. Human population density is low in most of the range, so impacts related to urbanization and development are generally low and show minimal change under future scenarios B1 and A2 in 2040. Future scenarios in 2060 demonstrate an increase of urbanization in some analytical units, resulting in a decrease in resiliency of four analytical units under scenario B1 and five analytical units under scenario A2; however, seven analytical units remain in moderate or high condition in scenario B1, while eight units remain in moderate or high condition in scenario A2. Although change is predicted to occur due to threats on the landscape, our analysis indicates that the magnitude of change under both scenarios and timesteps does not indicate a significant risk to future viability of the Yazoo crayfish. The species is expected to experience slight reductions in resiliency by 2060, but moderate and high resiliency populations are expected to remain across the species' range. In addition, recent increases in sampling efforts have resulted in significant expansion of the species' current range, and it is predicted that future increases in sampling efforts will produce similar results. After assessing the best available information, we conclude that the Yazoo crayfish is not likely to become endangered within the foreseeable future throughout all of its range.

We evaluated the range of the Yazoo crayfish to determine if it is in danger of extinction now or likely to become so within the foreseeable future in any portion of its range. The species is a range-limited, stream-dwelling species that occurs within a very small area distributed among scattered locations in the Yazoo and Big Black River drainages of Mississippi. The range of a species theoretically can be divided into portions in an infinite number of ways. We focused our analysis on portions of the species' range that may meet the Act's definition of an “endangered species” or a “threatened species.” We considered whether the threats or their effects on the Yazoo crayfish 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 or likely to become so within the foreseeable future in that portion. Based on the best available science, these factors are not concentrated within a specific portion of the species' range but spread throughout its range.

Currently, there are moderate and high resiliency populations occurring in each ecoregion. In Northern Hilly Gulf Coastal Plain, there are two moderate resiliency populations and one low resiliency population. In Southern Hilly Gulf Coastal Plain, there are two low resiliency populations and one high resiliency population. In Loess Plain, there are two moderate resiliency populations and four high resiliency populations. We project in the future at least one moderate and/or high resiliency population occurring in each ecoregion: In Northern Hilly Gulf Coastal Plain, there are projected to be two low resiliency populations and one moderate resiliency population; in Southern Hilly Gulf Coastal Plain, there are projected to be two very low resiliency populations and one moderate resiliency population; and in Loess Plain, there are projected to be three moderate resiliency populations and three high resiliency populations. The current and future condition analyses of the Yazoo crayfish indicate sufficient resiliency, representation, and redundancy in each ecoregion. As a result, there are no portions of the species' range where the species has a different biological status from its rangewide biological status. Therefore, we conclude that there are no portions of the species' range that warrant further consideration, and the species is not in danger of extinction or likely to become so within the foreseeable future in any significant portion of its range.

After assessing the best available information, we conclude that the Yazoo crayfish is not in danger of extinction or likely to become in danger of extinction within the foreseeable future throughout all of its range or in any significant portion of its range. Therefore, we find that listing the Yazoo crayfish as an “endangered species” or “threatened species” under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the Yazoo crayfish species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R4-ES-2023-0134 (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo on the Peer Review Process, we solicited independent scientific reviews of the information contained in the Yazoo crayfish SSA report. The Service sent the SSA report to five independent peer reviewers and received two responses. Results of this structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as appropriate, in the SSA report, which is the foundation for this finding.

On January 14, 1977, we published a final rule ( 42 FR 2965 ) to list the southern sea otter as a threatened species. On March 10, 2021, we received a November 2020 petition from the Pacific Legal Foundation, counsel for California Sea Urchin Commission and Commercial Fishermen of Santa Barbara, requesting that the southern sea otter ( Enhydra lutris nereis ) be removed from the Federal List of Endangered and Threatened Wildlife ( i.e., “delisted”) because the species does not meet the Act's definition of an endangered or a threatened species. On August 23, 2022, we published a 90-day finding (87 FR 51635) that the petition presented substantial scientific or commercial information indicating that delisting the southern sea otter may be warranted. This document constitutes our 12-month finding on the March 10, 2021, petition to delist southern sea otter.

The southern sea otter historically ranged from Oregon in the United States (which is thought to have been a transition zone between the northern and southern subspecies), to the species' southern range terminus near Punta Abreojos, Baja California, Mexico. The maritime fur trade of the 18th and 19th centuries caused the near-extinction of sea otters throughout their North Pacific range. All present-day southern sea otters descended from a small remnant population that survived the fur trade near Bixby Creek in Monterey County, California. Currently, the subspecies occurs only in portions of California: along roughly 500 km (310 mi) of the mainland coastline from San Mateo County to Santa Barbara County, and in the waters surrounding San Nicolas Island, Ventura County, although occasionally individuals are documented in other areas.

Southern sea otters occupy a variety of coastal marine habitats, including rocky exposed coastline, sandy embayments, and estuaries. Sea otter habitat in California is typically defined by the 40 m (131 ft) or 60 m (197 ft) depth contour. Depending on local bathymetry, most sea otters in California reside within 2 km (1.2 mi) of shore. At the individual level, sea otters need benthic invertebrate prey, coastal marine waters less than 40 m (131 ft) in depth, and sheltered resting habitat consisting of canopy-forming kelp, shallow protected waters ( e.g., estuaries), or haul out areas. At the population level, sea otters need sufficient abundance and adequate rates of survival, recruitment, and dispersal to rebound from disturbance and persist at the population or metapopulation scale. At the species level, sea otters need adequate redundancy to spread the risk of large-scale, high-impact ( i.e., catastrophic) events among multiple populations or areas; they also need adequate genetic and environmental diversity to be able to adapt to changing environmental conditions.

For additional information on the physical characteristics, genetics, taxonomy, habitat, life history, and historical and current distribution, see chapter 3 of the SSA report (Service 2023, pp. 12-26. For additional information on population and species needs, see chapter 3 of the SSA report (Service 2023, pp. 22-23).

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the southern sea otter, and we evaluated all relevant factors under the five listing factors including any regulatory mechanisms and conservation measures addressing these threats. We examined the following threats: curtailment of its range; harmful algal or cyanobacterial bloom intoxication; shark bite mortality; end-lactation syndrome; cardiac disease; protozoal infection; acanthocephalan peritonitis; infections (other); natural causes (other); human causes (shootings, boat strikes, and entanglements); human causes (oil spills); loss of genetic diversity; and climate change, including synergistic and cumulative effects. Of these threats, the southern sea otter is currently most imperiled by high shark bite mortality, curtailment of its range, and changes related to climate.

Due in part to listing under the Act in 1977 and ongoing conservation efforts, the range-wide population index for southern sea otters has increased to 2,962 as of 2019 (the most recent year a full census was completed); the mainland range has increased by approximately 210 km (130 mi) to encompass roughly 500 km (310 mi) of linear coastline; and a translocated subpopulation has taken hold at San Nicolas Island. Although current numbers and range remain restricted, the southern sea otter is likely to sustain populations in the wild in the near term. The current abundance of 2,962 otters is far below estimated carrying capacity of California, but above the roughly 50 animals that remained in 1914. Seven of 29+ subpopulations are currently extant. However, the results of population projections based on three plausible future scenarios indicated that meaningful improvements in resiliency, redundancy, and representation are unlikely to occur within the foreseeable future.

As noted above, the southern sea otter remains most imperiled by high shark bite mortality, the curtailment of its range, and climate change and associated effects. Based on our projections of future conditions for the species, and the existing and increased threats in the future on the species from shark bite mortality, range curtailment, and impacts of climate change, the species will experience continued and increasing impacts on its abundance and connectivity between populations that will most likely cause the species to be increasingly less able to support itself into the future. Additionally, existing regulatory mechanisms and conservation measures do not appear to be sufficient to protect the southern sea otter from emerging or intensifying threats.

After assessing the best available information, we concluded that southern sea otter is likely to become in danger of extinction within the foreseeable future throughout all of its range. Therefore, we find that delisting the southern sea otter under the Act is not warranted. A detailed discussion of the basis for this finding can be found in the southern sea otter species assessment form and other supporting documents on https://www.regulations.gov under Docket No. FWS-R8-ES-2023-0132 (see ADDRESSES , above).

In accordance with our July 1, 1994, peer review policy (59 FR 34270; July 1, 1994) and the Service's August 22, 2016, Director's Memo on the Peer Review Process, we solicited independent scientific reviews of the information contained in the southern sea otter SSA report. The Service sent the SSA report to three independent peer reviewers and three partner reviewers. We received responses back from one peer reviewer and one partner reviewer. Results of this structured peer review process can be found at https://www.regulations.gov. We incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this finding.

We request that you submit any new information concerning the taxonomy, biology, ecology, status of, or stressors to the Cascades frog, plains spotted skunk, sicklefin chub, southern sea otter, sturgeon chub, Tennessee cave salamander, or Yazoo crayfish to the appropriate person, as specified under FOR FURTHER INFORMATION CONTACT , whenever it becomes available. New information will help us monitor these species and make appropriate decisions about their conservation and status. We encourage local agencies and stakeholders to continue cooperative monitoring and conservation efforts.

A list of the references cited in each petition finding is available in the relevant species assessment form, which is available on the internet at https://www.regulations.gov in the appropriate docket (see ADDRESSES , above) and upon request from the appropriate person (see FOR FURTHER INFORMATION CONTACT , above).

The primary authors of this document are the staff members of the Species Assessment Team, Ecological Services Program.

The authority for this action is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq. ).