[Federal Register Volume 86, Number 124 (Thursday, July 1, 2021)]
[Rules and Regulations]
[Pages 34979-34998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13800]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2019-0059; FF09E21000 FXES11110900000 212]
RIN 1018-BD09


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Suwannee Moccasinshell

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), designate 
critical habitat for the Suwannee moccasinshell (Medionidus walkeri) 
under the Endangered Species Act of 1973 (Act), as amended. In total, 
approximately 190 miles (306 kilometers) of stream channels in Alachua, 
Bradford, Columbia, Dixie, Gilchrist, Hamilton, Lafayette, Madison, 
Suwannee, and Union Counties, Florida, and Brooks and Lowndes Counties, 
Georgia, fall within the boundaries of the critical habitat 
designation. The effect of this regulation is to designate critical 
habitat for the Suwannee moccasinshell under the Act.

DATES: This rule is effective August 2, 2021.

ADDRESSES: This final rule is available on the internet at http://www.regulations.gov under Docket No. FWS-R4-ES-2019-0059 and at https://www.fws.gov/panamacity/. Comments and materials we received, as well 
as some supporting documentation we used in preparing this rule, are 
available for public inspection at http://www.regulations.gov. All of 
the comments, materials, and documentation that we considered in this 
rulemaking are available upon mailed request from U.S. Fish and 
Wildlife Service, Panama City Ecological Services Field Office, 1601 
Balboa Avenue, Panama City, FL 32405; or by telephone 850-769-0552.
    The coordinates or plot points or both from which the maps are 
generated are included in the administrative record for this critical 
habitat designation and are available at http://www.regulations.gov at 
Docket No. FWS-R4-ES-2019-0059, and at the Panama City Ecological 
Services Field Office at https://www.fws.gov/panamacity/ (see FOR 
FURTHER INFORMATION CONTACT). Any additional tools or supporting 
information that we developed for this critical habitat designation 
will also be available at the

[[Page 34980]]

U.S. Fish and Wildlife Service website and upon mailed request to the 
Field Office set out above, and may also be included in the preamble 
and at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Jay B. Herrington, Field Supervisor, 
U.S. Fish and Wildlife Service, Panama City Ecological Services Field 
Office, 1601 Balboa Avenue, Panama City, FL 32405; telephone 850-769-
0552. Persons who use a telecommunications device for the deaf (TDD) 
may call the Federal Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under Section 4(a)(3) of the Act, if 
we determine that a species is endangered or threatened, we must 
designate critical habitat to the maximum extent prudent and 
determinable. Designations and revisions of critical habitat can only 
be completed by issuing a rule. We listed the Suwannee moccasinshell as 
a threatened species on November 7, 2016 (81 FR 69417). We are 
designating a total of approximately 190 mi (306 km) of stream channel 
in three units as critical habitat for the Suwannee moccasinshell.
    Basis for this rule. Section 3(5)(A) of the Act defines critical 
habitat as (i) the specific areas within the geographical area occupied 
by the species, at the time it is listed, on which are found those 
physical or biological features (I) essential to the conservation of 
the species and (II) which may require special management 
considerations or protections; and (ii) specific areas outside the 
geographical area occupied by the species at the time it is listed, 
upon a determination by the Secretary that such areas are essential for 
the conservation of the species. Section 4(b)(2) of the Act states that 
the Secretary must make the designation on the basis of the best 
scientific data available and after taking into consideration the 
economic impact, the impact on national security, and any other 
relevant impacts of specifying any particular area as critical habitat.
    Economic analysis. In accordance with section 4(b)(2) of the Act, 
we prepared an economic analysis of the impacts of designating critical 
habitat for the Suwannee moccasinshell. We published the announcement 
of, and solicited public comments on, the draft economic analysis (DEA; 
84 FR 65325, November 27, 2019). Because we received no comments on the 
DEA, we adopted the DEA as a final version.
    Peer review and public comment. In accordance with our peer review 
policy published on July 1, 1994 (59 FR 34270), we solicited expert 
opinion from three knowledgeable individuals with scientific expertise 
that included familiarity with the Suwannee moccasinshell and its 
habitat, biological needs, and threats. We received a response from one 
peer reviewer who agreed with the information in the proposed critical 
habitat rule. We also considered all comments and information received 
from the public during the comment period on the proposed designation.

Previous Federal Actions

    On October 6, 2015 (80 FR 60335), we proposed to list the Suwannee 
moccasinshell as a threatened species. On October 6, 2016 (81 FR 
69417), we published the final listing rule, which added the Suwannee 
moccasinshell to the List of Endangered and Threatened Wildlife in 
title 50 of the Code of Federal Regulations at 50 CFR 17.11(h). On 
November 27, 2019 (84 FR 65325), we proposed to designate critical 
habitat for the Suwannee moccasinshell. All other previous Federal 
actions for the Suwannee moccasinshell are described in one or more of 
the documents discussed above.

Summary of Comments and Recommendations

    In our November 27, 2019, proposed critical habitat rule, we 
requested written comments from the public on the proposed designation 
and the associated DEA by January 27, 2020. We also contacted 
appropriate Federal, State, and local agencies; scientific 
organizations; and other interested parties and invited them to comment 
on the proposed critical habitat designation and DEA during the comment 
period. Notices of the availability of these documents for review and 
inviting public comment were published by the Tallahassee Democrat on 
December 4, 2019, Gainesville Sun and Gilchrist Journal on December 5, 
2019, and Valdosta Daily Times and Suwannee Democrat on December 11, 
2019. We received nine comments during the 60-day comment period. We 
did not receive any requests for a public hearing. All substantive 
information provided during the comment period has either been 
incorporated directly into this final determination or is addressed 
below.

Comments From States

    Section 4(b)(5)(A)(ii) of the Act requires the Service to give 
actual notice of any designation of lands that are considered to be 
critical habitat to the appropriate agency of each State in which the 
species is believed to occur, and invite each such agency to comment on 
the proposed regulation. The Florida Fish and Wildlife Conservation 
Commission (FWC) provided comments in support of the designation of 
critical habitat, and provided additional information related to 
current and future threats. Specifically, the FWC provided a 
publication by Holcomb et al. (2018, entire) on the strong connection 
between spring discharge and species occupancy; information on a 
proposed surface mining operation along the New River; and a 
publication by Neupane et al. (2019, entire) that assessed the 
hydrologic responses to projected climate change in the Suwannee River 
basin. We incorporated this new information into the final rule.

Public Comments

    We received eight public comments on the proposed rule. Several 
commenters indicated support for the habitat protection of the Suwannee 
moccasinshell. None of the comments were substantive so as to require 
the Service's response.

Summary of Changes From the Proposed Rule

    After consideration of the comments we received during the public 
comment period (refer to Summary of Comments and Recommendations 
above), and new information published or obtained since the proposed 
rule was published, we made changes to the final critical habitat rule. 
Many small, nonsubstantive changes and corrections, not affecting the 
determination (e.g., updating the Background section in response to 
comments, minor clarifications), were made throughout the document. 
Below is a summary of changes made to the final rule.
    (1) We incorporated information on the strong connection between 
spring discharge and species occupancy from Holcomb et al. (2018, 
entire) into the discussion of natural flow regimes in the Habitats 
Protected From Disturbance section under Physical or Biological 
Features Essential to the Conservation of the Species.
    (2) We incorporated information from Neupane et al. (2018, entire), 
provided by FWC (see above), that assessed the hydrologic responses to 
projected climate change scenarios in the Suwannee River basin into the 
discussion of natural flow regimes in the Habitats Protected From 
Disturbance section under Physical or Biological Features Essential to 
the Conservation of the Species.
    (3) We incorporated information received from FWC (see above) on a

[[Page 34981]]

proposed surface mining operation in the upper Santa Fe River sub-basin 
into the discussion of physical or biological features that may require 
special management considerations or protection within Unit 1 under 
Final Critical Habitat Designation.

Critical Habitat

Background

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features:
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Our regulations at 50 CFR 424.02 define the geographical area 
occupied by the species as: An area that may generally be delineated 
around species' occurrences, as determined by the Secretary (i.e., 
range). Such areas may include those areas used throughout all or part 
of the species' life cycle, even if not used on a regular basis (e.g., 
migratory corridors, seasonal habitats, and habitats used periodically, 
but not solely by vagrant individuals).
    Conservation, as defined under section 3 of the Act, means to use 
and the use of all methods and procedures that are necessary to bring 
an endangered or threatened species to the point at which the measures 
provided pursuant to the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping, and transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot be otherwise 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that Federal agencies ensure, in consultation 
with the Service, that any action they authorize, fund, or carry out is 
not likely to result in the destruction or adverse modification of 
critical habitat. The designation of critical habitat does not affect 
land ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow the government 
or public to access private lands. Such designation does not require 
implementation of restoration, recovery, or enhancement measures by 
non-Federal landowners. Where a landowner requests Federal agency 
funding or authorization for an action that may affect a listed species 
or critical habitat, the Federal agency would be required to consult 
with the Service under section 7(a)(2) of the Act. However, even if the 
Service were to conclude that the proposed activity would result in 
destruction or adverse modification of the critical habitat, the 
Federal action agency and the landowner are not required to abandon the 
proposed activity, or to restore or recover the species; instead, they 
must implement ``reasonable and prudent alternatives'' to avoid 
destruction or adverse modification of critical habitat.
    Under the first prong of the Act's definition of critical habitat, 
areas within the geographical area occupied by the species at the time 
it was listed are included in a critical habitat designation if they 
contain physical or biological features (1) which are essential to the 
conservation of the species and (2) which may require special 
management considerations or protection. For these areas, critical 
habitat designations identify, to the extent known using the best 
scientific and commercial data available, those physical or biological 
features that are essential to the conservation of the species (such as 
space, food, cover, and protected habitat). In identifying those 
physical or biological features that occur in specific occupied areas, 
we focus on the specific features that are essential to support the 
life-history needs of the species, including, but not limited to, water 
characteristics, soil type, geological features, prey, vegetation, 
symbiotic species, or other features. A feature may be a single habitat 
characteristic or a more complex combination of habitat 
characteristics. Features may include habitat characteristics that 
support ephemeral or dynamic habitat conditions. Features may also be 
expressed in terms relating to principles of conservation biology, such 
as patch size, distribution distances, and connectivity.
    Under the second prong of the Act's definition of critical habitat, 
we may designate critical habitat in areas outside the geographical 
area occupied by the species at the time it is listed, upon a 
determination that such areas are essential for the conservation of the 
species. When designating critical habitat, the Secretary will first 
evaluate areas occupied by the species. The Secretary will only 
consider unoccupied areas to be essential where a critical habitat 
designation limited to geographical areas occupied by the species would 
be inadequate to ensure the conservation of the species. In addition, 
for an unoccupied area to be considered essential, the Secretary must 
determine that there is a reasonable certainty both that the area will 
contribute to the conservation of the species and that the area 
contains one or more of those physical or biological features essential 
to the conservation of the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Further, our Policy on 
Information Standards under the Endangered Species Act (published in 
the Federal Register on July 1, 1994 (59 FR 34271)), the Information 
Quality Act (section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), 
and our associated Information Quality Guidelines provide criteria, 
establish procedures, and provide guidance to ensure that our decisions 
are based on the best scientific data available. They require our 
biologists, to the extent consistent with the Act and with the use of 
the best scientific data available, to use primary and original sources 
of information as the basis for recommendations to designate critical 
habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally from 
the information developed during the listing process for the species. 
Additional information sources may include any generalized conservation 
strategy, criteria, or outline that may have been developed for the 
species, the recovery plan for the species, articles in peer-reviewed 
journals, conservation plans developed by States and counties, 
scientific status surveys and studies, biological assessments, other 
unpublished materials, or experts' opinions or personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is

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unimportant or may not be needed for recovery of the species. Areas 
that are important to the conservation of the species, both inside and 
outside the critical habitat designation, will continue to be subject 
to: (1) Conservation actions implemented under section 7(a)(1) of the 
Act; (2) regulatory protections afforded by the requirement in section 
7(a)(2) of the Act for Federal agencies to ensure their actions are not 
likely to jeopardize the continued existence of any endangered or 
threatened species; and (3) the prohibitions found in section 9 of the 
Act. Federally funded or permitted projects affecting listed species 
outside their designated critical habitat areas may still result in 
jeopardy findings in some cases. These protections and conservation 
tools will continue to contribute to recovery of this species. 
Similarly, critical habitat designations made on the basis of the best 
available information at the time of designation will not control the 
direction and substance of future recovery plans, habitat conservation 
plans (HCPs), or other species conservation planning efforts if new 
information available at the time of these planning efforts calls for a 
different outcome.

Physical or Biological Features Essential to the Conservation of the 
Species

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

Space for Individual and Population Growth and for Normal Behavior

    Mussels generally live embedded in the bottom of stable streams and 
other bodies of water, in areas where flow velocities are sufficient to 
remove finer sediments and provide well-oxygenated waters. The Suwannee 
moccasinshell inhabits creeks and rivers where it is found in 
substrates of sand or a mixture of sand and gravel, and in areas with 
slow to moderate current (Williams 2015, p. 2). The species is often 
associated with large woody material embedded in the substrate, which 
may help stabilize substrates and act as a flow refuge. The Suwannee 
moccasinshell, similar to other freshwater mussels, is dependent on 
areas with flow refuges, where shear stress is relatively low and 
sediments remain stable during high flow events (Strayer 1999, pp. 468, 
472; Hastie et al. 2001, pp. 111-114; Gangloff and Feminella 2007, p. 
71). Substrates that remain stable in high flows conceivably allow 
these relatively sedentary animals to remain in the same general 
location throughout their entire lives. These habitat conditions not 
only provide space for Suwannee moccasinshell populations, but also 
provide cover and shelter and sites for breeding, reproduction, and 
growth of offspring.

Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements

    Freshwater mussels, such as the Suwannee moccasinshell, siphon 
water into their shells and across four gills that are specialized for 
respiration, food collection, and brooding larvae in females. Food 
items include fine detritus (particles of organic debris), algae, 
diatoms, and bacteria (Strayer et al. 2004, pp. 430-431, Vaughn et al. 
2008, p. 410). Adult mussels obtain food items both from the water 
column and from the sediment, either by taking water in through the 
incurrent siphon or by moving material extracted from sediments into 
their shell using cilia (hair-like structures) on their foot. For the 
first several months, juvenile mussels feed primarily with their foot, 
although they also may filter interstitial (pore) water (Yeager et al. 
1994, pp. 217-221). Food availability and quality for the Suwannee 
moccasinshell is affected by habitat stability, floodplain 
connectivity, flow, and water and sediment quality. Adequate food 
availability and quality is essential for normal behavior, growth, and 
viability during all life stages of this species.
    The Suwannee moccasinshell is a riverine species that depends upon 
adequate amounts of flowing water. Flowing water transports food items 
to the sedentary juvenile and adult life stages, provides oxygen for 
respiration, removes wastes, transports sperm to females, and maintains 
the stream bottom habitats where the species is found (the effects of 
flow alteration on habitat is discussed below under Habitats Protected 
From Disturbance). A sufficient amount of continuously flowing water is 
a feature essential to this species.
    Important water quality parameters for freshwater mussels include 
(but are not limited to) dissolved oxygen (DO), temperature, pH, 
salinity, and suspended sediment. As relatively sedentary animals, 
mussels must tolerate the full range of physical and chemical 
conditions that occur naturally within the streams where they persist, 
but many species are considered sensitive to disturbance. Water quality 
within the Suwannee River basin may vary according to season, geology, 
climate events, and human activities within the watershed. Dissolved 
oxygen (DO) and water temperature are important parameters for 
freshwater mussel early life stages, which are more sensitive to 
deviations from normal ranges. Water temperature also plays an 
important role in the overall water quality, including oxygen 
solubility and

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ammonia toxicity. Increased stream temperatures and decreased dissolved 
oxygen concentrations are important secondary effects associated with 
flow reduction and cessation (Haag and Warren 2008, pp. 1174-1176). 
Sensitive mussel species like the Suwannee moccasinshell may suffer 
lethal and nonlethal effects to low dissolved oxygen levels and 
elevated stream temperatures (Gagnon et al. 2004, p. 672; Golladay et 
al. 2004, p. 501; Haag and Warren 2008, pp. 1174-1176; Spooner and 
Vaughn 2008, p. 313), and are particularly susceptible to these 
conditions during early life stages (Sparks and Strayer 1998, pp. 132-
133; Pandolfo et al. 2010, p. 965; Archambault et al. 2013, p. 247). 
Water temperatures of not more than 91 [deg]F (32 [deg]C), and DO 
concentrations of not less than 5.0 milligrams per liter (mg/L) 
represent important thresholds for freshwater mussels (Sparks and 
Strayer 1998, pp. 132-133; Gagnon et al. 2004, p. 672; Pandolfo et al. 
2010, p. 965; Khan et al. 2019, p. 6). The specific physical and 
chemical tolerance ranges needed by the Suwannee moccasinshell for 
normal behavior, growth, and viability of all life stages have not been 
investigated. In the absence of species-specific data, we are using the 
current numeric standards for water quality criteria adopted by the 
States under the Clean Water Act (CWA). We find these criteria 
represent sustainable levels for aquatic life that would provide for 
the conservation of the species.

Sites for Breeding, Reproduction, or Rearing (or Development) of 
Offspring

    Sites for breeding, reproduction, and development are tied to areas 
in stable rivers and creeks where flow velocities are sufficient to 
maintain habitats, and bottom substrates are composed of sand or a 
mixture of sand and gravel (see Space for Individual and Population 
Growth and for Normal Behavior above). Juvenile mussels depend upon 
areas where substrates remain stable during high flow events. The 
presence of large embedded logs may contribute to substrate stability 
and act as flow refuges. The larvae of most freshwater mussels are 
parasitic, requiring a period of encystment on a fish host in order to 
transform into juvenile mussels. Thus, the presence of appropriate host 
fishes to complete its reproductive life cycle is essential to the 
Suwannee moccasinshell. In laboratory host trials, Suwannee 
moccasinshell larvae transformed primarily on the blackbanded darter 
(Percina nigrofasciata) and to a lesser extent on the brown darter 
(Etheostoma edwini) (Johnson et al. 2016, p. 171). The blackbanded 
darter is one of the most abundant darter species in coastal plain 
streams, and the distribution of both fish species overlap with the 
historical distribution of the Suwannee moccasinshell (Kuehne and 
Barbour 1983, pp. 29-30; Robins et al. 2018, pp. 317, 336).

Habitats Protected From Disturbance

    The Suwannee moccasinshell's habitat has been impacted by pollution 
and reduced flows throughout its range, and by channel instability and 
excessive sedimentation in portions of its range (see Factor A, The 
Present or Threatened Destruction, Modification, or Curtailment of Its 
Habitat or Range of the proposed listing rule).
    An environment free from toxic levels of pollutants is essential to 
the Suwannee moccasinshell, especially to its early life stages. There 
is no specific information on the sensitivity of the species to common 
municipal, agricultural, and industrial pollutants. However, as a 
group, freshwater mussels are more sensitive to pollution than many 
other aquatic organisms and are one of the first species to respond to 
water quality impacts (Haag 2012, p. 355). A detailed discussion of 
pollution issues in the basin and potential effects to the Suwannee 
moccasinshell is provided in the proposed listing rule (80 FR 60335) 
under Factor A.
    The Suwannee moccasinshell depends upon a natural flow regime to 
maintain its benthic habitats. Altered flow regimes (including higher 
peak flows, lower base flows, and changes to seasonal flow pulses) 
within the basin are attributable to altered stormwater runoff 
patterns, lowering of the groundwater table, recent periods of drought, 
and climate change. Developed areas and some agricultural lands shed 
water extremely quickly during storm events. Urban areas significantly 
affect water quantity because of the high percentage of impervious 
cover and increases in water consumption. Rainfall on impervious 
surfaces is immediately transported to stream channels, causing 
increases in flow volume and velocity. These effects are discussed 
further in the next section and in the final listing rule under Factor 
A, Stream Channel Instability.
    Because less infiltration occurs in developed areas, less 
groundwater recharge occurs and stream base flows may be reduced. The 
distinctive geology of the Suwannee River basin relies heavily on 
spring discharge to buffer the tannic waters of the mainstem, and 
groundwater recharge is limited in the region due to confinement of the 
aquifer. Over 250 springs located in this system have been threatened 
by increased demand for water resources within the basin and adjacent 
basins. The combined effects of groundwater pumping and prolonged 
droughts have resulted in lower groundwater tables and reduced flow and 
dewatering of basin streams and springs for extended periods (Grubbs 
and Crandall 2007, p. 78; Torak et al. 2010, pp. 46-47). The springs 
provide refugia for aquatic organisms during periods of drought when 
groundwater has the most influence on water quality and quantity. 
Recent surveys found the species only in portions of the basin with 
significant contributions from spring discharge and failed to locate 
the species in areas without this influence (Holcomb et al. 2018, pp. 
99-100). The strong connection between spring discharge and Suwannee 
moccasinshell occupancy indicates that groundwater discharge via 
springs is important to maintaining flows and water quality needed by 
the species, especially during drought (Holcomb et al. 2018, p. 95).
    Reductions in stream flow may also alter hydraulically mediated 
sediment sorting throughout the river, which may displace or otherwise 
alter Suwannee moccasinshell habitat. Climate scenarios for the years 
2050 and 2080 predict changes to seasonal and annual hydrology of the 
Suwannee River basin due to a wetter and warmer climate in the region 
(Neupane et al. 2018, pp. 2232-2238). Within the basin, surface runoff 
is projected to increase as a result of increased precipitation, and 
summer stream flow is projected to decrease substantially (up to 25%) 
by 2080 due to the effects of higher air temperature (Neupane et al. 
2018, p. 2240).
    Because freshwater mussels are relatively long-lived and have 
limited mobility, habitat stability is a requirement shared by nearly 
all freshwater mussels (Haag 2012, p. 106). Optimal substrate 
conditions for the Suwannee moccasinshell include consolidated sand or 
sand and gravel mixtures, without excessive accumulations of sediment 
or detritus, and that remain stable during high flows. These substrates 
are dependent on geomorphically stable stream channels and intact 
riparian areas (Allan et al. 1997, p. 149; Rosgen 1996, pp. 8-11). 
Stable stream channels consistently transport their sediment load, such 
that the stream bed neither degrades nor aggrades, and have lower 
suspended sediment loads (Rosgen 1996, pp. 1-3), which mussels require 
in order to efficiently feed, respire, and reproduce. Stable stream 
channels are formed and maintained by natural flow regimes, channel 
features (dimension,

[[Page 34984]]

pattern, and profile), and natural sediment input to the system through 
periodic flooding, which maintains connectivity and interaction with 
the floodplain. Habitat instability is induced by changes in natural 
sediment or flow regimes, and by physical modifications to the stream 
channel or floodplain (channel instability is discussed further under 
Factor A of the final listing rule).

Summary of Essential Physical or Biological Features

    We have determined that the following physical or biological 
features are essential to the conservation of Suwannee moccasinshell:
    (1) Geomorphically stable stream channels (channels that maintain 
lateral dimensions, longitudinal profiles, and sinuosity patterns over 
time without an aggrading or degrading bed elevation).
    (2) Stable substrates of muddy sand or mixtures of sand and gravel, 
and with little to no accumulation of unconsolidated sediments and low 
amounts of filamentous algae.
    (3) A natural hydrologic flow regime (magnitude, frequency, 
duration, and seasonality of discharge over time) necessary to maintain 
benthic habitats where the species is found, and connectivity of stream 
channels with the floodplain, allowing the exchange of nutrients and 
sediment for habitat maintenance, food availability, and spawning 
habitat for native fishes.
    (4) Water quality conditions needed to sustain healthy Suwannee 
moccasinshell populations, including low pollutant levels (not less 
than State criteria), a natural temperature regime, pH (between 6.0 to 
8.5), adequate oxygen content (not less than State criteria), hardness, 
turbidity, and other chemical characteristics necessary for normal 
behavior, growth, and viability of all life stages.
    (5) The presence of abundant fish hosts necessary for recruitment 
of the Suwannee moccasinshell. The presence of blackbanded darters 
(Percina nigrofasciata) and brown darters (Etheostoma edwini) will 
serve as an indication of fish host presence.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing contain features that are essential to the conservation of 
the species and which may require special management considerations or 
protection.
    All three units that we are designating as critical habitat, 
including the unit that was occupied by the species at the time of 
listing, have mixed ownership of adjacent riparian lands, with mainly 
private (72 percent) and State (27 percent) lands (Table 1). All State-
owned riparian lands are in Florida, and the majority are managed by 
Florida's Suwannee River Water Management District (District). Tracts 
are managed to maintain adequate water supply and water quality for 
natural systems by preserving riparian habitats and restricting 
development (SRWMD 2014, p. 3).
    The District established minimum flows and levels for the lower 
Suwannee River, downstream of Fanning Springs and for the upper Santa 
Fe River. Minimum flow and level criteria establish a limit at which 
further withdrawals would be detrimental to water resources, taking 
into consideration fish and wildlife habitats, the passage of fish, 
sediment loads, and water quality, among others (SRWMD 2005, pp. 6-8; 
SRWMD 2007, entire). In addition, the Suwannee River and Santa Fe River 
systems have been designated Outstanding Florida Waters, which prevents 
the permitted discharge of pollutants that would lower existing water 
quality of, or significantly degrade, such waters. While these programs 
may indirectly alleviate some detrimental impacts on aquatic habitats, 
there currently are no plans or agreements designed specifically for 
the conservation of the Suwannee moccasinshell or for freshwater 
mussels in general.
    The features essential to the conservation of the Suwannee 
moccasinshell may require special management considerations or 
protection to ameliorate the following threats: Altered flow regimes, 
nonpoint source pollution (from stormwater runoff or infiltration), 
point source pollution (from wastewater discharges or accidental 
releases), physical alterations to the stream channel (for example, 
dredging, straightening, impounding, etc.), and altered physical and 
chemical water quality parameters (especially, temperature, dissolved 
oxygen, turbidity, pH, and salinity). Special management considerations 
or protection may be required within critical habitat areas to 
ameliorate these threats, and include (but are not limited to): (1) 
Moderation of surface and ground water withdrawals; (2) improvement of 
the treatment of wastewater discharged from permitted facilities and 
the operation of those facilities; (3) reductions in pesticide and 
fertilizer use especially in groundwater recharge areas and near stream 
channels; (4) use of best management practices designed to reduce 
sedimentation, erosion, and stream bank alteration; (5) protection and 
restoration of riparian buffers; and (6) avoidance of physical 
alterations to stream channels and adjacent floodplains. This list 
applies only to Federal actions (see the Application of the ``Adverse 
Modification'' Standard below for more information).

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(2) of the Act, we use the best 
scientific data available to designate critical habitat. In accordance 
with the Act and our implementing regulations at 50 CFR 424.12(b), we 
review available information pertaining to the habitat requirements of 
the species and identify specific areas within the geographical area 
occupied by the species at the time of listing and any specific areas 
outside the geographical area occupied by the species to be considered 
for designation as critical habitat. As discussed in more detail below, 
we are designating critical habitat in areas within the geographical 
area occupied by the species at the time of listing. We also are 
designating specific areas outside the geographical area occupied by 
the species at the time of listing because we have determined that a 
designation limited to occupied areas would be inadequate--and 
therefore designation of unoccupied areas is essential--to ensure the 
conservation of the species.
    On December 16, 2020, we published a final rule in the Federal 
Register (85 FR 81411) adding a definition of ``habitat'' to our 
regulations for purposes of critical habitat designations under the 
Endangered Species Act of 1973, as amended (Act). This rule became 
effective on January 15, 2021 and only applies to critical habitat 
rules for which a proposed rule was published after January 15, 2021. 
Consequently, this new regulation does not apply to this final rule.
    The current distribution of the species is much reduced from its 
historical range. We anticipate that recovery will require continued 
protection of the existing population and its habitat, as well as 
reintroduction of Suwannee moccasinshell into historically occupied 
areas, ensuring there are multiple viable populations and that they 
occur over a wide geographic area. Range-wide recovery considerations, 
such as maintaining existing genetic diversity and striving for 
representation of all major portions of the species' current range, 
were considered in formulating the critical habitat.

[[Page 34985]]

    For this rule, we delineated critical habitat unit boundaries using 
the following criteria:
    (1) We compiled all available occurrence data records.
    (2) We used confirmed presences between the years 2000 and 2016 as 
the foundation for identifying areas currently occupied.
    (3) We evaluated habitat suitability of stream segments currently 
occupied by the species and retained all occupied stream segments.
    (4) We evaluated unoccupied stream segments for suitability, 
connectivity, and expansion, and identified areas containing the 
components comprising the physical or biological features that may 
require special management considerations or protection.
    (5) We omitted some unoccupied areas that are highly degraded and 
are not likely restorable (e.g., insufficient flowing water, channel 
destabilized), and, therefore, are not considered essential for the 
conservation of the species.
    (6) We delineated boundaries of critical habitat units based on the 
above information.
    Specific criteria and methodology used to determine critical 
habitat unit boundaries are discussed below.
    Sources of data for this critical habitat designation include 
multiple databases maintained by Florida Fish and Wildlife Conservation 
Commission, Dr. James D. Williams, Florida Museum of Natural History, 
and U.S. Geological Survey; verified museum records from multiple 
institutions (see Methods in Johnson et al. 2016, pp. 164-165); and a 
status report by Blalock-Herod and Williams (2001, entire). Historical 
and recent occurrence data included records collected from May 1916 to 
March 2016. Many surveys were conducted throughout the Suwannee River 
basin by Florida Fish and Wildlife Conservation Commission biologists 
during 2012-2016, and all sites with historical occurrences of Suwannee 
moccasinshell were sampled during this period. Sources of information 
pertaining to habitat requirements of the Suwannee moccasinshell 
include observations recorded during surveys and information contained 
in Blalock-Herod and Williams (2001, entire) and Williams et al. (2014, 
pp. 278-280).

Areas Occupied at the Time of Listing

    We define ``currently occupied'' as river reaches with positive 
surveys from 2000 to 2016. In making these determinations, we 
recognized that known occurrences for some mussel species are extremely 
localized, and rare mussels can be difficult to locate. In addition, 
stream habitats are highly dependent upon upstream and downstream 
channel habitat conditions for their maintenance. Therefore, we 
considered the entire reach between the uppermost and lowermost 
currently occupied locations to delineate the probable upstream and 
downstream extent of the Suwannee moccasinshell's distribution. Within 
the current range of the species, some habitats may or may not be 
actively utilized by individuals, but we consider these areas to be 
occupied at the scale of the geographic range of the species.
    We are designating as critical habitat for the Suwannee 
moccasinshell one occupied unit in the Suwannee River and lower Santa 
Fe River. This area contains one or more of the physical or biological 
features essential to the conservation of the Suwannee moccasinshell, 
and those physical or biological features may require special 
management conditions or protections. However, this single population 
provides little redundancy for the species, and a series of back-to-
back stochastic events or a single catastrophic event could 
significantly reduce or extirpate this one population. Consequently, we 
have determined that the occupied area is inadequate to ensure the 
conservation of the species. Therefore, we have also identified, and 
are designating as critical habitat, unoccupied areas that are 
essential for the conservation of the species.

Areas Not Occupied at the Time of Listing

    We are designating two unoccupied units as critical habitat. The 
units have some of the physical or biological features essential to the 
conservation of the species, and we are reasonably certain that each 
will contribute to the conservation of the species. Our specific 
rationale for each unit can be found in the unit descriptions below.
    An examination of all available collection data shows that the 
Suwannee moccasinshell's range and numbers have declined over time (see 
``Distribution and Abundance'' discussion in the final listing rule). 
For example, despite considerable survey effort, the species has not 
been collected in the lower Suwannee River or Withlacoochee River sub-
basins since the 1960s, and was last collected in the upper Santa Fe 
River sub-basin in 1996 (Johnson et al. 2016, p. 170). There has also 
been a reduction in numbers, with fewer individuals encountered during 
recent surveys than were collected historically (Johnson et al. 2016, 
pp. 166, 170).
    The Suwannee moccasinshell's reduced range and small population 
size may increase its vulnerability to many threats. Aquatic species 
with small ranges, few populations, and small or declining population 
sizes are the most vulnerable to extinction (Primack 2008, p. 137; Haag 
2012, p. 336). The effects of certain environmental pressures, 
particularly habitat degradation and loss, catastrophic weather events, 
and introduced species, are greater when population size is small 
(Soul[eacute] 1980, pp. 33, 71; Primack 2008, pp. 133-137, 152). 
Threats to the Suwannee moccasinshell are compounded by its reduced and 
linear distribution, with nearly the entire population presently 
distributed within the Suwannee River mainstem. A small population also 
occurs in the lower Santa Fe River; however, only 5 recent collections 
(3 of which are relic shell) have been reported in this sub-basin 
(Johnson et al. 2016, p. 171).
    A larger population of Suwannee moccasinshell occurring over a wide 
geographic area can have higher resilience. A large population is 
better able to return to pre-disturbance numbers after stochastic 
events, and also has increased availability of mates and reduced risk 
of genetic drift and inbreeding depression. The minimum viable 
population size needed to withstand stochastic events is not known for 
mussels. For species with complex life histories like freshwater 
mussels, maximizing the chances of viability over the long term, likely 
requires a population of considerable size (Haag 2012, p. 371). 
Reestablishing viable populations in the Withlacoochee and upper Santa 
Fe River sub-basins increases Suwannee moccasinshell redundancy by 
expanding its range into historically occupied areas, potentially 
increasing population size, and providing refuge from catastrophic 
events (for example, flooding and spills) in the Suwannee River.
    We determined the Withlacoochee and upper Santa Fe River sub-basins 
have the potential for future reoccupation by the species, provided 
that stressors are managed and mitigated. These specific areas 
encompass the minimum area of the species' historical range within the 
critical habitat designation, while still providing ecological 
diversity so that the species has the ability to evolve and adapt over 
time (representation) to ensure that the species has an adequate level 
of redundancy to guard against future catastrophic events. These areas 
also represent the stream reaches within the historical range with the 
best potential for recovery of the species due

[[Page 34986]]

to their current conditions and likely suitability for reintroductions. 
Accordingly, we are designating one unoccupied unit in the upper Santa 
Fe River and one unoccupied unit in the Withlacoochee River. As 
described below in the individual unit descriptions, each unit contains 
one or more of the physical or biological features and is reasonably 
certain to contribute to the conservation of the species.

General Information on the Maps of the Critical Habitat Designation

    The critical habitat streams were mapped with USGS National 
Hydrography Dataset GIS data. The high-resolution 1:24,000 flowlines 
were used to delineate the upstream and downstream boundaries of the 
critical habitat units and to calculate river kilometers and miles, 
according to the criteria explained below. The downstream boundary of a 
unit is the confluence of a named tributary stream or spring, below the 
farthest downstream occurrence record. The upstream boundary is the 
confluence of the first major tributary, road-crossing bridge, or a 
permanent barrier to fish passage above the farthest upstream 
occurrence record. The confluence of a large tributary typically marks 
a significant change in the size of the stream and is a logical and 
recognizable upstream terminus. Likewise, a dam or other barrier to 
fish passage marks the upstream extent to which mussels may disperse 
via their fish hosts. In the unit descriptions, distances between 
landmarks marking the upstream or downstream extent of a stream segment 
are given in river kilometers (km) and equivalent miles (mi), as 
measured tracing the course of the stream, not straight-line distance.
    The areas designated as critical habitat include only stream 
channels within the ordinary high-water line. States were granted 
ownership of lands beneath navigable waters up to the ordinary high-
water line upon achieving statehood (Pollard v. Hagan, 44 U.S. (3 How.) 
212 (1845)). Prior sovereigns or the States may have made grants to 
private parties that included lands below the ordinary high-water mark 
of some navigable waters that are included in this rule. Most, if not 
all, lands beneath the navigable waters included in this final rule are 
owned by the States of Florida and Georgia. The lands beneath most non-
navigable waters included in this final rule are in private ownership.
    There are no developed areas within the critical habitat boundaries 
except for transportation crossings, which do not remove the 
suitability of these areas for this species. The scale of the maps we 
prepared under the parameters for publication within the Code of 
Federal Regulations may not reflect the exclusion of such developed 
lands. Any such lands inadvertently left inside critical habitat 
boundaries shown on the maps of this rule have been excluded by text in 
the rule and are not designated as critical habitat. Therefore, a 
Federal action involving these lands would not trigger section 7 
consultation with respect to critical habitat and the requirement of no 
adverse modification unless the specific action would affect the 
physical or biological features in the adjacent critical habitat.
    The critical habitat designation is defined by these maps, as 
modified by any accompanying regulatory text, presented at the end of 
this document in the text of the rule itself. We include more detailed 
information on the boundaries of the critical habitat designation in 
the preamble of this document. The coordinates on which each map is 
based are available at the Service's internet site, (https://www.fws.gov/panamacity), (http://www.regulations.gov) at Docket No. 
FWS-R4-ES-2019-0059, and at the field office responsible for this 
designation (see FOR FURTHER INFORMATION CONTACT above).

Final Critical Habitat Designation

    We are designating approximately 306 km (190 mi) of stream channel 
in three units as critical habitat for the Suwannee moccasinshell. The 
three units we are designating as critical habitat are: Unit 1: 
Suwannee River, Unit 2: Upper Santa Fe River, and Unit 3: Withlacoochee 
River. About 81 percent of critical habitat for the Suwannee 
moccasinshell is already designated as critical habitat for either of 
two ESA-listed species: The oval pigtoe (Pleurobema pyriforme) or the 
Gulf sturgeon (Acipenser oxyrinchus desotoi). The table below shows the 
critical habitat units for the Suwannee moccasinshell and ownership of 
riparian lands adjacent to the units.

                         Table of Critical Habitat Units for the Suwannee Moccasinshell
  [Ownership of riparian lands adjacent to the units is given for each streambank in kilometers (km) and miles
         (mi). Lengths greater than 10 kilometers are rounded to the nearest whole kilometer and mile.]
----------------------------------------------------------------------------------------------------------------
                                                    Private km                                    Unit length km
                      Bank                             (mi)        State km (mi)  County km (mi)       (mi)
----------------------------------------------------------------------------------------------------------------
Unit 1: Suwannee River, FL......................  ..............  ..............  ..............     187 (116.2)
    Right descending bank *.....................        133 (83)         51 (31)       3.1 (1.9)  ..............
    Left descending bank *......................        133 (83)         53 (33)       1.5 (0.9)  ..............
                                                 ---------------------------------------------------------------
        Total...................................       266 (165)        103 (64)       4.6 (2.9)  ..............
Unit 2: Upper Santa Fe River, FL................  ..............  ..............  ..............       43 (26.7)
    Right descending bank.......................         34 (21)       8.4 (5.2)       0.4 (0.3)  ..............
    Left descending bank........................         26 (16)          13 (8)       3.6 (2.2)  ..............
                                                 ---------------------------------------------------------------
        Total...................................         61 (38)         22 (13)         4 (2.5)  ..............
Unit 3: Withlacoochee River, FL and GA..........  ..............  ..............  ..............     75.5 (46.9)
    Right descending bank.......................         58 (36)         17 (11)               0  ..............
    Left descending bank........................         53 (33)         22 (14)               0  ..............
                                                 ---------------------------------------------------------------
        Total...................................        112 (69)         39 (25)               0  ..............
----------------------------------------------------------------------------------------------------------------
Note: Totals may not sum due to rounding.
* Right and left descending bank is that bank of a stream when facing in the direction of flow or downstream.


[[Page 34987]]

    We present brief descriptions of all units, and reasons why they 
meet the definition of critical habitat for the Suwannee moccasinshell, 
below.

Unit 1: Suwannee River, Florida

    Unit 1 consists of approximately 187 km (116 mi) of the Suwannee 
River and lower Santa Fe River in Alachua, Columbia, Dixie, Gilchrist, 
Lafayette, Madison, and Suwannee Counties, Florida. The unit includes 
the Suwannee River mainstem from the confluence of Hart Springs (near 
river kilometer 71) in Dixie and Gilchrist Counties, upstream 137 km 
(85 mi) to the confluence of the Withlacoochee River in Madison and 
Suwannee Counties; and the Santa Fe River from its confluence with the 
Suwannee River in Suwannee and Gilchrist Counties, upstream 50 km (31 
mi) to the river's rise in Alachua County. The Santa Fe River flows 
underground for about 5 km (3.1 mi), ``sinking'' at O'Leno State Park 
and ``rising'' at River Rise Preserve State Park. The lower and upper 
portions of the Santa Fe River are intermittently connected during high 
flow events. The riparian lands along stream reaches in this unit are 
generally privately owned agricultural or silvicultural lands, or 
State-owned or -managed conservation lands (Table 1).
    The Suwannee moccasinshell occupies all stream reaches in this 
unit, which contains most of the physical or biological features 
essential to the conservation of the Suwannee moccasinshell. However, 
decreases in stream flow and changes in water quality, especially 
increased nitrogen loads and algae growth, are recognized issues in all 
stream reaches within the unit (SRWMD 2017, pp. 26-27, 42-50). During 
drought, depressed dissolved oxygen levels and elevated water 
temperatures may also be degraded in some reaches. Therefore, physical 
or biological features 3 and 4 are not consistently present in the 
unit. Currently, 73 percent of Unit 1 is designated critical habitat 
for the Gulf sturgeon (a migratory fish). Some small urban areas also 
are located near the two rivers.
    Special management considerations and protections that may be 
required to address threats within the unit include: Minimizing ground 
and surface water withdrawals or other actions that alter stream 
hydrology; reducing the use of fertilizers and pesticides, especially 
in spring recharge areas and near stream channels; improving treatment 
of wastewater discharged from permitted facilities and the operation of 
those facilities; implementing practices that protect or restore 
riparian buffer areas along stream corridors; avoidance of physical 
alternations to the stream channel and floodplain; prohibiting the 
removal of pre-cut submerged timber (deadhead logs); and establishing 
and enforcing restrictions on boat speed and length, especially in the 
lower Santa Fe River. Many of these measures would also be implemented 
in stream reaches upstream of the unit to adequately protect habitat 
within the unit. For example, a large surface mining project is 
proposed adjacent the New River within the upper Santa Fe River 
watershed. If the mining operation and its associated structures are 
constructed as currently proposed, we anticipate that physical or 
biological features 3 and 4 would be negatively impacted to a 
significant degree within the unit. In addition, groundwater discharge 
via springs is important to maintaining flows and water quality needed 
by the species, especially during drought (Holcomb et al., 2018, p. 
95). Therefore, spring recharge areas and aquifers may also need to be 
protected in order to fully address threats within the unit.

Unit 2: Upper Santa Fe River, Florida

    Unit 2 consists of approximately 43 km (27 mi) of the Santa Fe 
River and New River in Alachua, Bradford, Columbia, and Union Counties, 
Florida. The unit includes the Santa Fe River from the river's sink in 
Alachua County, upstream 36.5 km (23 mi) to the confluence of Rocky 
Creek in Bradford and Alachua Counties; and the New River from its 
confluence with the Santa Fe River, upstream 6.5 km (4 mi) to the 
confluence of Five Mile Creek in Union and Bradford Counties. The 
riparian lands along stream channels in this unit are generally 
privately owned agricultural or silvicultural lands, or are State-owned 
or -managed conservation lands (Table 1). All of Unit 2 is also 
designated critical habitat for the oval pigtoe (a freshwater mussel). 
The Suwannee moccasinshell was routinely represented in historical 
collections in the upper Santa Fe sub-basin; however, it is the only 
mussel species not detected in contemporary surveys. Unit 2 retains the 
features of a natural stream channel and presently supports a diverse 
mussel fauna, including several mussel species known to co-occur with 
the Suwannee moccasinshell. This unit has at least one of the physical 
or biological features essential to the conservation of the species, 
and we are reasonably certain that this area will contribute to the 
conservation of the species. Our specific rationale for this unit can 
be found below.
    This area is essential for the conservation of the species because 
it would improve its resiliency and redundancy of the species, which is 
necessary to conserve and recover the Suwanee moccasinshell. To improve 
the species' overall viability by increasing resiliency and redundancy, 
it is important to reestablish Suwannee moccasinshell populations in 
its former range in the Santa Fe River sub-basin (i.e., Unit 2). 
Presently, nearly the entire population of the species is linearly 
distributed within the Suwannee River and vulnerable to catastrophic 
events (for example, contaminant spills or severe floods), as well as 
to random fluctuations in population size or environmental conditions 
(Haag and Williams 2014, p. 48). Therefore, reestablishing populations 
in Unit 2 would reduce its extinction risk by expanding its current 
range into areas beyond the mainstem by providing connectivity to 
already occupied areas, space for growth and population expansion in 
portions of historical habitat, and refugia areas from threats in the 
Suwannee River.
    Although it is considered unoccupied, portions of this unit contain 
some or all of the physical or biological features essential for the 
conservation of the species. Unit 2 possesses characteristics described 
by physical or biological features 1 and 2 as long reaches of stable 
stream channel and suitable substrates are present throughout much of 
the unit. Unit 2 retains the features of a natural stream channel and 
presently supports a diverse mussel fauna, including several mussel 
species that ordinarily co-occur with the Suwannee moccasinshell. Both 
fish species found to serve as larval hosts for the Suwannee 
moccasinshell occur within the unit (Robins et al., 2018, pp. 317, 
336). Physical or biological features 3 and 4 are degraded in the Unit 
during some times of the year. Flow levels in the upper Santa Fe River 
have declined over time, and the river has ceased to flow multiple 
times since 2000 (Johnson et al., 2016, p. 170). An important effect of 
reduced flows is altered water quality, especially depressed dissolved 
oxygen levels and elevated water temperatures (discussed above under 
``Physical or Biological Features''). In 2007, the District developed 
minimum flow levels to establish flows protective of ``fish and 
wildlife habitats and the passage of fish'' in the upper Santa Fe River 
(SRWMD 2007, entire). The restoration of natural flow levels is a 
complex issue that will require considerable involvement and 
collaboration of Federal, State, and local governments and private 
landowners to implement projects that reduce groundwater

[[Page 34988]]

pumping in order to recover aquifer levels and sustain base flows in 
the upper Santa Fe River sub-basin. However, if implemented, water 
management strategies would improve physical or biological features 3 
and 4. The need for conservation efforts is recognized by our 
conservation partners, and methods for restoring natural flow regimes 
and reintroducing the species into unoccupied habitat are being 
advocated and developed. Accordingly, we are reasonably certain this 
unit will contribute to the conservation of the species.

Unit 3: Withlacoochee River, Georgia and Florida

    Unit 3 consists of approximately 75.5 km (47 mi) of the 
Withlacoochee River in Madison and Hamilton Counties, Florida, and 
Brooks and Lowndes Counties, Georgia. The unit includes the 
Withlacoochee River from its confluence with the Suwannee River in 
Madison and Hamilton Counties, FL, upstream 75.5 km (47 mi) to the 
confluence of Okapilco Creek in Brooks and Lowndes Counties, GA. The 
riparian lands along stream channels in this unit are generally 
privately owned agricultural or silvicultural lands (Table 1). Unit 3 
is within the historical range of the Suwannee moccasinshell but is not 
currently occupied by the species. Twenty-five percent of Unit 3 is 
also designated critical habitat for the Gulf sturgeon. Unit 3 retains 
the features of a natural stream channel and supports a diverse mussel 
fauna, including several mussel species known to co-occur with the 
Suwannee moccasinshell. This unit has at least one of the physical or 
biological features essential to the conservation of the species and we 
are reasonably certain that this area will contribute to the 
conservation of the species. Our specific rationale for this unit can 
be found below.
    This area is essential for the conservation of the species because 
it would improve the resiliency and redundancy of the species, which is 
necessary to conserve and recover the Suwanee moccasinshell. Presently, 
nearly the entire population of the species is linearly distributed 
within the Suwannee River (see Unit 1 above) and vulnerable to 
catastrophic events (for example, contaminant spills or severe floods) 
as well as to random fluctuations in population size or environmental 
conditions (Haag and Williams 2014, p. 48). Reestablishing populations 
in Withlacoochee River sub-basin would reduce its extinction risk by 
expanding its current range into areas beyond the mainstem by providing 
connectivity to already occupied areas, space for growth and population 
expansion in portions of historical habitat, and refugia areas from 
threats in the Suwannee River.
    Although it is considered unoccupied, portions of this unit contain 
some or all of the physical or biological features essential for the 
conservation of the species. Specifically, Unit 3 possesses 
characteristics described by physical or biological features 1 and 2 as 
long reaches of stable stream channel with suitable substrates are 
present within the unit. Unit 3 retains the features of a natural 
stream channel and supports a diverse mussel fauna, including several 
mussel species that ordinarily co-occur with the Suwannee 
moccasinshell. Both fish species found to serve as larval hosts for the 
Suwannee moccasinshell occur within the unit (Robins et al. 2018, pp. 
317, 336). Therefore, we find that the unit has the potential to 
support the species' life-history functions.
    Physical or biological feature 4 is in degraded condition, and 
pollution may have contributed to the Suwannee moccasinshell's decline 
in Unit 3. The domestic wastewater treatment plant for the city of 
Valdosta, GA is approximately 14 river miles upstream of the unit and 
has a history of untreated sewage releases to the Withlacoochee River 
after heavy rain events. However, major renovations to the city's sewer 
system were completed in June 2016 with the construction of a new 
treatment plant. Additional projects to address continued problems with 
sewage spills are ongoing, and the construction of a large retention 
basin is planned. If these improvements are realized, water quality 
could be restored to levels necessary to support the species.
    The need for conservation efforts is recognized by our conservation 
partners, and methods for restoring and reintroducing the species into 
unoccupied habitat are being developed. The Florida Fish and Wildlife 
Conservation Commission and Georgia Department of Natural Resources 
have expressed support for including this area in a critical habitat 
designation (Florida Fish and Wildlife Conservation Commission 2019; 
Georgia Department of Natural Resources 2018). Accordingly, we are 
reasonably certain this unit will contribute to the conservation of the 
species.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they fund, authorize, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species. In 
addition, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action that is likely to 
jeopardize the continued existence of any species listed under the Act 
or result in the destruction or adverse modification of critical 
habitat.
    We published a final regulation with a new definition of 
destruction or adverse modification on August 27, 2019 (84 FR 45020). 
Destruction or adverse modification means a direct or indirect 
alteration that appreciably diminishes the value of critical habitat as 
a whole for the conservation of a listed species.
    If a Federal action may affect a listed species or its critical 
habitat, the responsible Federal agency (action agency) must enter into 
consultation with us. Examples of actions that are subject to the 
section 7 consultation process are actions on State, Tribal, local, or 
private lands that require a Federal permit (such as a permit from the 
U.S. Army Corps of Engineers under section 404 of the Clean Water Act 
(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 
or authorized, do not require section 7 consultation.
    Compliance with the requirements of section 7(a)(2), is documented 
through our issuance of:
    (1) A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    (2) A biological opinion for Federal actions that may affect and 
are likely to adversely affect, listed species or critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species and/or 
destroy or adversely modify critical habitat, we provide reasonable and 
prudent alternatives to the project, if any are identifiable, that 
would avoid the likelihood of jeopardy and/or destruction or adverse 
modification of critical habitat. We define ``reasonable and prudent 
alternatives'' (at 50 CFR

[[Page 34989]]

402.02) as alternative actions identified during consultation that:
    (1) Can be implemented in a manner consistent with the intended 
purpose of the action,
    (2) Can be implemented consistent with the scope of the Federal 
agency's legal authority and jurisdiction,
    (3) Are economically and technologically feasible, and
    (4) Would, in the Director's opinion, avoid the likelihood of 
jeopardizing the continued existence of the listed species and/or avoid 
the likelihood of destroying or adversely modifying critical habitat.
    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 require Federal agencies to reinitiate 
consultation on previously reviewed actions in instances where we have 
listed a new species or subsequently designated critical habitat that 
may be affected and the Federal agency has retained discretionary 
involvement or control over the action (or the agency's discretionary 
involvement or control is authorized by law). Consequently, Federal 
agencies sometimes may need to request reinitiation of consultation 
with us on actions for which formal consultation has been completed, if 
those actions with discretionary involvement or control may affect 
subsequently listed species or designated critical habitat.
    Overall, about 81 percent of critical habitat proposed for the 
Suwannee moccasinshell is already designated as critical habitat for 
either the oval pigtoe or Gulf sturgeon. For Federal actions within 
areas already designated as critical habitat for these species, 
conservation measures we would recommend for the Suwannee moccasinshell 
are likely to be the same or very similar to those we already recommend 
for the oval pigtoe and Gulf sturgeon. New additional conservation 
measures will, however, likely be needed within that portion of Unit 3 
that is unoccupied by the Suwannee moccasinshell but not currently 
designated critical habitat for the Gulf sturgeon.

Application of the ``Destruction or Adverse Modification'' Standard

    The key factor related to the destruction or adverse modification 
determination is whether, with implementation of the proposed Federal 
action, the affected critical habitat would continue to serve its 
intended conservation role for the species. Activities that may destroy 
or adversely modify critical habitat are those that result in a direct 
or indirect alteration that appreciably diminishes the value of 
critical habitat as a whole for the conservation of the Suwannee 
moccasinshell. As discussed above, the role of critical habitat is to 
support physical or biological features essential to the conservation 
of a listed species and provide for the conservation of the species.
    Section 4(b)(8) of the Act requires us to briefly evaluate and 
describe, in any proposed or final regulation that designates critical 
habitat, activities involving a Federal action that may destroy or 
adversely modify such habitat, or that may be affected by such 
designation.
    Activities that may affect critical habitat, when carried out, 
funded, or authorized by a Federal agency, should result in 
consultation for the Suwannee moccasinshell. These activities include, 
but are not limited to:
    (1) Actions that would introduce contaminants or alter water 
chemistry or temperature. Such activities could include, but are not 
limited to, release of chemical or biological pollutants, or heated 
effluents into the surface water or connected groundwater at a point 
source or by dispersed release (nonpoint source). These activities 
could alter water quality conditions to levels that are beyond the 
tolerances of the mussel or its fish host.
    (2) Actions that would reduce flow levels or alter flow regimes. 
This could include, but is not limited to, activities that lower 
groundwater levels including groundwater pumping and surface water 
withdrawal or diversion. These activities can result in long-term 
reduced stream flows, which may cause streams to stop flowing or dry 
up; and also may decrease oxygen levels, elevate water temperatures, 
degrade water quality, and cause sediments to accumulate. These 
activities could alter flow levels beyond the tolerances of the mussel 
or its fish host.
    (3) Actions that would significantly increase the filamentous algal 
community within the stream channel. Such activities could include, but 
are not limited to, release of nutrients into the surface water or 
connected groundwater at a point source or by dispersed release 
(nonpoint source). These activities can result in excessive filamentous 
algae filling streams and reducing habitat for the mussel and its fish 
host, degrading water quality during their decay, and decreasing oxygen 
levels at night from their respiration. Thick algal mats can also 
entrain young mussels and prevent juveniles from settling into the 
sediment. These activities could degrade the habitat and reduce oxygen 
levels below the tolerances of the mussel or its fish host.
    (4) Actions that would significantly alter channel morphology or 
cause channel instability. Such activities could include but are not 
limited to channelization, impoundment, road and bridge construction, 
mining, dredging, destruction of riparian vegetation, and land 
clearing. These activities may lead to changes in flow regimes, erosion 
of the streambed and banks, and excessive sedimentation that could 
degrade the habitat of the mussel or its fish host.
    (5) Actions that would cause significant amounts of sediments to 
enter the stream channel. Such activities could include but are not 
limited to livestock grazing, road and bridge construction, channel 
alteration, incompatible with best management practices, commercial and 
residential development, and other watershed and floodplain 
disturbances. These activities could eliminate or degrade the habitat 
necessary for the growth and reproduction of the mussel or its fish 
host.

Exemptions

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

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

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

    Section 4(b)(2) of the Act states that the Secretary shall 
designate and make revisions to critical habitat on the basis of the 
best available scientific data after taking into consideration the 
economic impact, national security impact, and any other relevant 
impact of specifying any particular area as critical habitat. The 
Secretary may exclude an area from critical habitat if he determines 
that the benefits of such exclusion outweigh the

[[Page 34990]]

benefits of specifying such area as part of the critical habitat, 
unless he determines, based on the best scientific data available, that 
the failure to designate such area as critical habitat will result in 
the extinction of the species. In making the determination to exclude a 
particular area, the statute on its face, as well as the legislative 
history, are clear that the Secretary has broad discretion regarding 
which factor(s) to use and how much weight to give to any factor. On 
December 18, 2020, we published a final rule in the Federal Register 
(85 FR 82376) revising portions of our regulations pertaining to 
exclusions of critical habitat. These final regulations became 
effective on January 19, 2021 and apply to critical habitat rules for 
which a proposed rule was published after January 19, 2021. 
Consequently, these new regulations do not apply to this final rule.
    When considering the benefits of exclusion, we consider, among 
other things, whether exclusion of a specific area is likely to result 
in conservation; the continuation, strengthening, or encouragement of 
partnerships; or implementation of a management plan. In the case of 
the Suwannee moccasinshell, the benefits of critical habitat include 
public awareness of the presence of the species and the importance of 
habitat protection, and, where a Federal nexus exists, increased 
habitat protection for the Suwannee moccasinshell due to protection 
from adverse modification or destruction of critical habitat. In 
practice, situations with a Federal nexus exist primarily on Federal 
lands or for projects undertaken by Federal agencies. Additionally, 
continued implementation of an ongoing management plan that provides 
equal to or more conservation than a critical habitat designation would 
reduce the benefits of including that specific area in the critical 
habitat designation.
    We describe below the process that we undertook for taking into 
consideration each category of impacts and our analyses of the relevant 
impacts.

Consideration of Economic Impacts

    Section 4(b)(2) of the Act and its implementing regulations require 
that we consider the economic impact that may result from a designation 
of critical habitat. To assess the probable economic impacts of a 
designation, we must first evaluate specific land uses or activities 
and projects that may occur in the area of the critical habitat. We 
then must evaluate the impacts that a specific critical habitat 
designation may have on restricting or modifying specific land uses or 
activities for the benefit of the species and its habitat within the 
designated areas. We then identify which conservation efforts may be 
the result of the species being listed under the Act versus those 
attributed solely to the designation of critical habitat for this 
particular species. The probable economic impact of a critical habitat 
designation is analyzed by comparing scenarios both ``with critical 
habitat'' and ``without critical habitat.''
    The ``without critical habitat'' scenario represents the baseline 
for the analysis, which includes the existing regulatory and socio-
economic burden imposed on landowners, managers, or other resource 
users potentially affected by the designation of critical habitat 
(e.g., under the Federal listing as well as other Federal, State, and 
local regulations). The baseline, therefore, represents the costs of 
all efforts attributable to the listing of the species under the Act 
(i.e., conservation of the species and its habitat incurred regardless 
of whether critical habitat is designated). The ``with critical 
habitat'' scenario describes the incremental impacts associated 
specifically with the designation of critical habitat for the species. 
The incremental conservation efforts and associated impacts would not 
be expected without the designation of critical habitat for the 
species. In other words, the incremental costs are those attributable 
solely to the designation of critical habitat, above and beyond the 
baseline costs. These are the costs we use when evaluating the benefits 
of inclusion and exclusion of particular areas from the final 
designation of critical habitat should we choose to conduct an optional 
section 4(b)(2) exclusion analysis.
    For this designation, we developed an incremental effects 
memorandum (IEM) considering the probable incremental economic impacts 
that may result from this designation of critical habitat. The 
information contained in our IEM was then used to develop a screening 
analysis of the probable effects of the designation (Industrial 
Economics 2020, entire). The purpose of the screening analysis is to 
filter out the geographic areas in which the critical habitat 
designation is unlikely to result in probable incremental economic 
impacts. In particular, the screening analysis considers baseline costs 
(i.e., absent critical habitat designation) and includes probable 
economic impacts where land and water use may be subject to 
conservation plans, land management plans, best management practices, 
or regulations that protect the habitat area as a result of the Federal 
listing status of the species. The screening analysis filters out 
particular areas of critical habitat that are already subject to such 
protections and are, therefore, unlikely to incur incremental economic 
impacts. Ultimately, the screening analysis allows us to focus our 
analysis on evaluating the specific areas or sectors that may incur 
probable incremental economic impacts as a result of the designation. 
The screening analysis also assesses whether units unoccupied by the 
species may require additional management or conservation efforts as a 
result of the critical habitat designation, and thus may incur 
incremental economic impacts. This screening analysis, combined with 
the information contained in our IEM, constitute our economic analysis 
of the critical habitat designation for the Suwannee moccasinshell and 
is summarized in the narrative below.
    Executive Orders 12866 and 13563 direct Federal agencies to assess 
the costs and benefits of available regulatory alternatives in 
quantitative (to the extent feasible) and qualitative terms. Consistent 
with the E.O. regulatory analysis requirements, our effects analysis 
under the Act may take into consideration impacts to both directly and 
indirectly affected entities, where practicable and reasonable. If 
sufficient data are available, we assess to the extent practicable the 
probable impacts to both directly and indirectly affected entities. As 
part of our screening analysis, we considered the types of economic 
activities that are likely to occur within the areas likely affected by 
the critical habitat designation. In our evaluation of the probable 
incremental economic impacts that may result from the designation of 
critical habitat for the Suwannee moccasinshell, first we identified, 
in the IEM dated June 30, 2016, probable incremental economic impacts 
associated with the following categories of activities: (1) Groundwater 
pumping; (2) agriculture; (3) mining; (4) grazing; (5) discharge of 
chemical pollutants; (6) roadway and bridge construction; (7) in-stream 
dams and diversions; (8) dredging; (9) commercial or residential 
development; (10) timber harvest; and (11) removal of large in-channel 
logs. We considered each industry or category individually. 
Additionally, we considered whether these activities would have any 
Federal involvement.
    Critical habitat designation generally will not affect activities 
that do not have any Federal involvement; under the Act, the 
designation of critical habitat only affects activities conducted, 
funded, permitted, or authorized by Federal agencies. In areas where 
the Suwannee moccasinshell is present, Federal

[[Page 34991]]

agencies already are required to consult with the Service under section 
7 of the Act on activities they fund, permit, or implement that may 
affect the species. Consultations to avoid the destruction or adverse 
modification of critical habitat will be incorporated into the existing 
consultation process.
    In our IEM, we attempted to clarify the distinction between the 
effects that will result from the species being listed and those 
attributable to the critical habitat designation (i.e., difference 
between the jeopardy and adverse modification standards) for the 
Suwannee moccasinshell's critical habitat. The following specific 
circumstances in this case help to inform our evaluation: (1) The 
physical or biological features identified for occupied critical 
habitat are the same features essential for the life requisites of the 
species and (2) any actions that would result in sufficient harm or 
harassment to constitute jeopardy to the Suwannee moccasinshell would 
also likely adversely affect the essential physical or biological 
features of occupied critical habitat. The IEM outlines our rationale 
concerning this limited distinction between baseline conservation 
efforts and incremental impacts of the designation of critical habitat 
for this species.
    The final critical habitat designation for the Suwannee 
moccasinshell totals approximately 306 kilometers (190 miles) of stream 
channels in three units. The riparian lands adjacent to critical 
habitat are under private (72 percent), State (27 percent), and county 
(1 percent) ownership. Unit 1 is the only occupied unit and is 61 
percent of the critical habitat designation. As discussed above, in 
this occupied area, any actions that may affect the species or its 
habitat would also affect designated critical habitat and it is 
unlikely that any additional conservation efforts would be recommended 
to address the adverse modification standard over and above those 
recommended as necessary to avoid jeopardizing the continued existence 
of the Suwannee moccasinshell. Therefore, only administrative costs are 
expected in actions affecting this unit. While this additional analysis 
will require time and resources by both the Federal action agency and 
the Service, it is believed that, in most circumstances, these costs, 
because they are predominantly administrative in nature, would not be 
significant.
    Units 2 and 3 are currently unoccupied by the species but are 
essential for the conservation of the species. These units total 119 km 
(78 mi) and comprise 39 percent of the critical habitat designation. In 
these unoccupied areas, any conservation efforts or associated probable 
impacts would be considered incremental effects attributed to the 
critical habitat designation.
    The screening analysis finds that the total annual incremental 
costs of critical habitat designation for the Suwannee moccasinshell 
are anticipated to be less than $100,000 per year. The highest costs 
are anticipated in Unit 3 because it is unoccupied by the species and 
is not already designated critical habitat for another mussel species 
(for comparison, see discussion for Unit 2 below). In this unit, the 
designation is anticipated to result in a small number of additional 
section 7 consultations (approximately three per year), primarily 
related to planned transportation projects that intersect the unit. 
Anticipated project modifications may include minimizing the extent of 
in-channel maintenance activities, relocation of discharge outfalls, or 
requiring strict adherence of water quality and habitat protections. 
Total annual costs to the Service and action agencies for consultations 
and project modifications in Unit 3 are anticipated to be less than 
$80,000 annually (Industrial Economics 2020, pp. 9-12).
    In Units 1 and 2, the economic costs of implementing the rule will 
most likely be limited to additional administrative efforts by the 
Service and action agencies to consider adverse modification. Unit 1 is 
occupied by the Suwannee moccasinshell, and conservation actions taken 
in order to be protective of the species would also be sufficient to 
protect its critical habitat. Unit 2 is also designated as critical 
habitat for the oval pigtoe, a freshwater mussel with nearly identical 
physical or biological features to the Suwannee moccasinshell. 
Conservation efforts taken to protect oval pigtoe critical habitat 
would also be sufficient to protect Suwannee moccasinshell critical 
habitat. Thus, additional project modifications are not anticipated in 
Units 1 and 2. In total, up to six section 7 consultations per year are 
anticipated to occur in Units 1 and 2, with total costs of less than 
$20,000 annually (Industrial Economics 2020, pp. 7-9).

Exclusions

Exclusions Based on Economic Impacts

    We solicited data and comments from the public regarding the 
economic analysis, as well as all aspects of the proposed rule. We did 
not receive any additional information on economic impacts during the 
public comment period to determine whether any specific areas should be 
excluded from the final critical habitat designation under authority of 
section 4(b)(2) and our implementing regulations at 50 CFR 424.19.
    Based on the above-described consideration of the economic impacts 
of the critical habitat designation, the Secretary is not exercising 
his discretion to exclude any areas from this designation of critical 
habitat for the Suwannee moccasinshell based on economic impacts.
    A copy of the IEM and economic screening analysis with supporting 
documents may be obtained by contacting the Panama City Ecological 
Services Field Office or from the field office's website (see 
ADDRESSES).

Exclusions Based on Impacts to National Security and Homeland Security

    In preparing this rule, we determined that none of the lands within 
the designated critical habitat for the Suwannee moccasinshell are 
owned or managed by the Department of Defense or Department of Homeland 
Security, and, therefore, we anticipate no impact on national security 
or homeland security. We did not receive any additional information 
during the public comment period for the proposed designation regarding 
impacts of the designation on national security or homeland security 
that would support excluding any specific areas from the final critical 
habitat designation under authority of section 4(b)(2) and our 
implementing regulations at 50 CFR 424.19.

Exclusions Based on Other Relevant Impacts

    Under section 4(b)(2) of the Act, we considered any other relevant 
impacts, in addition to economic impacts and impacts on national 
security. We considered a number of factors including whether there are 
permitted conservation plans covering the species in the area such as 
HCPs, safe harbor agreements, or candidate conservation agreements with 
assurances, or whether there are non-permitted conservation agreements 
and partnerships that would be encouraged by designation of, or 
exclusion from, critical habitat. In addition, we looked at the 
existence of Tribal conservation plans and partnerships and consider 
the government-to-government relationship of the United States with 
Tribal entities. We also considered any social impacts that might occur 
because of the designation.

[[Page 34992]]

    In preparing this final rule, we determined that there are 
currently no HCPs or other management plans for the Suwannee 
moccasinshell, and the final designation does not include any Tribal 
lands or trust resources. Therefore, we anticipate no impact on Tribal 
lands, partnerships, or HCPs from this final critical habitat 
designation. We did not receive any additional information during the 
public comment period for the proposed rule regarding other relevant 
impacts to support excluding any specific areas from the final critical 
habitat designation under authority of section 4(b)(2) and our 
implementing regulations at 50 CFR 424.19. Accordingly, the Secretary 
is not exercising his discretion to exclude any areas from this final 
designation based on other relevant impacts.

Required Determinations

Regulatory Planning and Review (Executive Orders 12866 and 13563)

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

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

    Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.), 
as amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (SBREFA; 5 U.S.C. 801 et seq.), whenever an agency is required to 
publish a notice of rulemaking for any proposed or final rule, it must 
prepare and make available for public comment a regulatory flexibility 
analysis that describes the effects of the rule on small entities 
(i.e., small businesses, small organizations, and small government 
jurisdictions). However, no regulatory flexibility analysis is required 
if the head of the agency certifies the rule will not have a 
significant economic impact on a substantial number of small entities. 
The SBREFA amended the RFA to require Federal agencies to provide a 
certification statement of the factual basis for certifying that the 
rule will not have a significant economic impact on a substantial 
number of small entities.
    According to the Small Business Administration, small entities 
include small organizations such as independent nonprofit 
organizations; small governmental jurisdictions, including school 
boards and city and town governments that serve fewer than 50,000 
residents; and small businesses (13 CFR 121.201). Small businesses 
include manufacturing and mining concerns with fewer than 500 
employees, wholesale trade entities with fewer than 100 employees, 
retail and service businesses with less than $5 million in annual 
sales, general and heavy construction businesses with less than $27.5 
million in annual business, special trade contractors doing less than 
$11.5 million in annual business, and agricultural businesses with 
annual sales less than $750,000. To determine if potential economic 
impacts to these small entities are significant, we considered the 
types of activities that might trigger regulatory impacts under this 
designation as well as types of project modifications that may result. 
In general, the term ``significant economic impact'' is meant to apply 
to a typical small business firm's business operations.
    Under the RFA, as amended, and as understood in the light of recent 
court decisions, Federal agencies are required to evaluate the 
potential incremental impacts of rulemaking on those entities directly 
regulated by the rulemaking itself; in other words, the RFA does not 
require agencies to evaluate the potential impacts to indirectly 
regulated entities. The regulatory mechanism through which critical 
habitat protections are realized is section 7 of the Act, which 
requires Federal agencies, in consultation with the Service, to ensure 
that any action authorized, funded, or carried out by the agency is not 
likely to destroy or adversely modify critical habitat. Therefore, 
under section 7, only Federal action agencies are directly subject to 
the specific regulatory requirement (avoiding destruction and adverse 
modification) imposed by critical habitat designation. Consequently, it 
is our position that only Federal action agencies would be directly 
regulated with the critical habitat designation. There is no 
requirement under the RFA to evaluate the potential impacts to entities 
not directly regulated. Moreover, Federal agencies are not small 
entities. Therefore, because no small entities would be directly 
regulated by this rulemaking, the Service certifies that the critical 
habitat designation will not have a significant economic impact on a 
substantial number of small entities.
    In summary, we have considered whether the designation would result 
in a significant economic impact on a substantial number of small 
entities. For the above reasons and based on currently available 
information, we certify that the critical habitat designation will not 
have a significant economic impact on a substantial number of small 
business entities. Therefore, a regulatory flexibility analysis is not 
required.

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

    Executive Order 13211 (Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use) requires 
agencies to prepare Statements of Energy Effects when undertaking 
certain actions. In our economic analysis, we did not find that this 
critical habitat designation would significantly affect energy 
supplies, distribution, or use. Therefore, this action is not a 
significant energy action, and no Statement of Energy Effects is 
required.

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

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), we make the following findings:
    (1) This rule will not produce a Federal mandate. In general, a 
Federal mandate is a provision in legislation, statute, or regulation 
that would impose an enforceable duty upon State, local, or tribal 
governments, or the private sector, and includes both ``Federal 
intergovernmental mandates'' and ``Federal private sector mandates.'' 
These terms are defined in 2 U.S.C. 658(5)-(7).'' Federal 
intergovernmental mandate'' includes a regulation that ``would impose 
an enforceable duty upon State, local, or tribal governments'' with two 
exceptions. It excludes ``a condition of Federal assistance.'' It also 
excludes ``a duty arising from participation in a voluntary Federal 
program,'' unless the regulation ``relates to a then-existing Federal 
program under which $500,000,000 or more is provided annually to State, 
local, and tribal governments under entitlement

[[Page 34993]]

authority,'' if the provision would ``increase the stringency of 
conditions of assistance'' or ``place caps upon, or otherwise decrease, 
the Federal Government's responsibility to provide funding,'' and the 
State, local, or tribal governments ``lack authority'' to adjust 
accordingly. At the time of enactment, these entitlement programs were: 
Medicaid; Aid to Families with Dependent Children work programs; Child 
Nutrition; Food Stamps; Social Services Block Grants; Vocational 
Rehabilitation State Grants; Foster Care, Adoption Assistance, and 
Independent Living; Family Support Welfare Services; and Child Support 
Enforcement. ``Federal private sector mandate'' includes a regulation 
that ``would impose an enforceable duty upon the private sector, except 
(i) a condition of Federal assistance or (ii) a duty arising from 
participation in a voluntary Federal program.''
    The designation of critical habitat does not impose a legally 
binding duty on non-Federal Government entities or private parties. 
Under the Act, the only regulatory effect is that Federal agencies must 
ensure that their actions do not destroy or adversely modify critical 
habitat under section 7. While non-Federal entities that receive 
Federal funding, assistance, or permits, or that otherwise require 
approval or authorization from a Federal agency for an action, may be 
indirectly impacted by the designation of critical habitat, the legally 
binding duty to avoid destruction or adverse modification of critical 
habitat rests squarely on the Federal agency. Furthermore, to the 
extent that non-Federal entities are indirectly impacted because they 
receive Federal assistance or participate in a voluntary Federal aid 
program, the Unfunded Mandates Reform Act would not apply, nor would 
critical habitat shift the costs of the large entitlement programs 
listed above onto State governments.
    (2) We do not believe that this rule will significantly or uniquely 
affect small governments because it would not produce a Federal mandate 
of $100 million or greater in any year; that is, it is not a 
``significant regulatory action'' under the Unfunded Mandates Reform 
Act. The designation of critical habitat imposes no obligations on 
State or local governments. By definition, Federal agencies are not 
considered small entities, although the activities they fund or permit 
may be proposed or carried out by small entities. Consequently, we do 
not believe that the critical habitat designation would significantly 
or uniquely affect small government entities. As such, a Small 
Government Agency Plan is not required.

Takings--Executive Order 12630

    In accordance with E.O. 12630 (Government Actions and Interference 
with Constitutionally Protected Private Property Rights), we have 
analyzed the potential takings implications of designating critical 
habitat for the Suwannee moccasinshell in a takings implications 
assessment. The Act does not authorize the Service to regulate private 
actions on private lands or confiscate private property as a result of 
critical habitat designation. Designation of critical habitat does not 
affect land ownership, or establish any closures, or restrictions on 
use of or access to the designated areas. Furthermore, the designation 
of critical habitat does not affect landowner actions that do not 
require Federal funding or permits, nor does it preclude development of 
habitat conservation programs or issuance of incidental take permits to 
permit actions that do require Federal funding or permits to go 
forward. However, Federal agencies are prohibited from carrying out, 
funding, or authorizing actions that would destroy or adversely modify 
critical habitat. A takings implications assessment has been completed 
and concludes that this designation of critical habitat for the 
Suwannee moccasinshell does not pose significant takings implications 
for lands within or affected by the designation.

Federalism--Executive Order 13132

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

Civil Justice Reform--Executive Order 12988

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

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

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

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    It is our position that, outside the jurisdiction of the U.S. Court 
of Appeals for the Tenth Circuit, we do not need to prepare 
environmental analyses pursuant to the National Environmental Policy 
Act in connection with

[[Page 34994]]

designating critical habitat under the Act. We published a notice 
outlining our reasons for this determination in the Federal Register on 
October 25, 1983 (48 FR 49244). This position was upheld by the U.S. 
Court of Appeals for the Ninth Circuit (Douglas County v. Babbitt, 48 
F.3d 1495 (9th Cir. 1995), cert. denied 516 U.S. 1042 (1996)).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination With Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
Tribes in developing programs for healthy ecosystems, to acknowledge 
that Tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to Tribes. We have determined that no Tribal 
lands would be affected by the designation.

References Cited

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

Authors

    The primary authors of this rulemaking are staff of the Panama City 
Ecological Services Field Office.

Signing Authority

    The Director, U.S. Fish and Wildlife Service, approved this 
document and authorized the undersigned to sign and submit the document 
to the Office of the Federal Register for publication electronically as 
an official document of the U.S. Fish and Wildlife Service. Martha 
Williams, Principal Deputy Director Exercising the Delegated Authority 
of the Director, U.S. Fish and Wildlife Service, approved this document 
on June 23, 2021, for publication.

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

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

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

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

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


0
2. Amend Sec.  17.11 in paragraph (h) by revising the entry for 
``Moccasinshell, Suwannee'' under ``Clams'' in the List of Endangered 
and Threatened Wildlife to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

----------------------------------------------------------------------------------------------------------------
                                                                                          Listing citations and
           Common name              Scientific name      Where listed         Status         applicable rules
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
              Clams
 
                                                  * * * * * * *
Moccasinshell, Suwannee.........  Medionidus walkeri  Wherever found....  T              81 FR 69417, 10/6/2016;
                                                                                          50 CFR 17.95(f).CH
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


0
3. Amend Sec.  17.95 in paragraph (f) by adding an entry for ``Suwannee 
Moccasinshell (Medionidus walkeri)'' immediately after the entry for 
``Fluted Kidneyshell (Ptychobranchus subtentum),'' to read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (f) * * *

Suwannee Moccasinshell (Medionidus walkeri)

    (1) Critical habitat units are depicted on the maps in this entry 
for Alachua, Bradford, Columbia, Dixie, Gilchrist, Hamilton, Lafayette, 
Madison, Suwannee, and Union Counties, Florida; and Brooks and Lowndes 
Counties, Georgia.
    (2) Within these areas, the physical or biological features 
essential to the conservation of Suwannee moccasinshell consist of the 
following components:
    (i) Geomorphically stable stream channels (channels that maintain 
lateral dimensions, longitudinal profiles, and sinuosity patterns over 
time without an aggrading or degrading bed elevation).
    (ii) Stable substrates of muddy sand or mixtures of sand and 
gravel, and with little to no accumulation of unconsolidated sediments 
and low amounts of filamentous algae.
    (iii) A natural hydrologic flow regime (magnitude, frequency, 
duration, and seasonality of discharge over time) necessary to maintain 
benthic habitats where the species is found, and connectivity of stream 
channels with the floodplain, allowing the exchange of nutrients and 
sediment for habitat maintenance, food availability, and spawning 
habitat for native fishes.
    (iv) Water quality conditions needed to sustain healthy Suwannee 
moccasinshell populations, including low pollutant levels (not less 
than State criteria), a natural temperature regime, pH (between 6.0 to 
8.5), adequate oxygen content (not less than State criteria), hardness, 
turbidity, and other chemical characteristics necessary for normal 
behavior, growth, and viability of all life stages.
    (v) The presence of fish hosts necessary for recruitment of the 
Suwannee moccasinshell. The presence of blackbanded darters (Percina 
nigrofasciata) and brown darters (Etheostoma edwini) will serve as an 
indication of fish host presence.
    (3) Critical habitat does not include manmade structures (such as 
buildings, aqueducts, dams, roads, and other paved areas) and the land 
on which they

[[Page 34995]]

are located existing within the legal boundaries on August 2, 2021.
    (4) Data layers defining map units were created with U.S. 
Geological Survey National Hydrography Dataset GIS data. The high-
resolution 1:24,000 flowlines were used to calculate river kilometers 
and miles. ESRIs ArcGIS 10.2.2 software was used to determine longitude 
and latitude coordinates using decimal degrees. The projection used in 
mapping all units was Universal Transverse Mercator, NAD 83, Zone 16 
North. The maps in this entry, as modified by any accompanying 
regulatory text, establish the boundaries of the critical habitat 
designation. The coordinates on which each map is based are available 
at http://www.regulations.gov at Docket No. FWS-R4-ES-2019-0059, the 
Service's internet site (https://www.fws.gov/panamacity), and at the 
field office responsible for this designation. You may obtain field 
office location by contacting one of the Service regional offices, the 
addresses of which are listed at 50 CFR 2.2.
    (5) Note: Index map of critical habitat units for the Suwannee 
moccasinshell in Florida and Georgia follows:
BILLING CODE 4333-15-P
[GRAPHIC] [TIFF OMITTED] TR01JY21.000

    (6) Unit 1: Suwannee River in Alachua, Columbia, Dixie, Gilchrist, 
Lafayette, Madison, and Suwannee Counties, Florida.
    (i) Unit 1 consists of approximately 187 kilometers (km) (116 miles 
(mi)) of

[[Page 34996]]

the Suwannee River and lower Santa Fe River in Alachua, Columbia, 
Dixie, Gilchrist, Lafayette, Madison, and Suwannee Counties, Florida. 
The unit includes the Suwannee River mainstem from the confluence of 
Hart Springs in Dixie and Gilchrist Counties, upstream 137 km (85 mi) 
to the confluence of the Withlacoochee River in Madison and Suwannee 
Counties; and the Santa Fe River from its confluence with the Suwannee 
River in Suwannee and Gilchrist Counties, upstream 50 km (31 mi) to the 
river's rise (the Santa Fe River runs underground for more than 3 
miles, emerging at River Rise Preserve State Park) in Alachua County.
    (ii) Map of Unit 1, Suwannee River, follows:
    [GRAPHIC] [TIFF OMITTED] TR01JY21.001
    
    (7) Unit 2: Upper Santa Fe River in Alachua, Bradford, Columbia, 
and Union, Counties, Florida.
    (i) The Upper Santa Fe River Unit consists of approximately 43 km 
(27 mi) of the Santa Fe River and New River in Alachua, Bradford, 
Columbia, and Union Counties, Florida. The unit includes the Santa Fe 
River from the river's sink in Alachua County, upstream 36.5 km (23 mi) 
to the confluence of Rocky Creek in Bradford and Alachua Counties; and 
the New River from its confluence with the Santa Fe River, upstream 6.5 
km (4 mi) to the confluence of Five Mile Creek in Union and Bradford 
Counties.

[[Page 34997]]

    (ii) Map of Unit 2, Upper Santa Fe River, follows:
    [GRAPHIC] [TIFF OMITTED] TR01JY21.002
    
    (8) Unit 3: Withlacoochee River in Hamilton and Madison Counties, 
Florida; Brooks and Lowndes Counties, Georgia.
    (i) The Withlacoochee River Unit consists of approximately 75.5 km 
(47 mi) of the Withlacoochee River in Hamilton and Madison Counties, 
Florida, and Brooks and Lowndes Counties, Georgia. The unit includes 
the Withlacoochee River from its confluence with the Suwannee River in 
Madison and Hamilton Counties, FL, upstream 75.5 km (47 mi) to the 
confluence of Okapilco Creek in Brooks and Lowndes Counties, GA.
    (ii) Map of Unit 3, Withlacoochee River, follows:

[[Page 34998]]

[GRAPHIC] [TIFF OMITTED] TR01JY21.003

* * * * *

Anissa Craghead,
Acting Regulations and Policy Chief, Division of Policy, Economics, 
Risk Management, and Analytics, Joint Administrative Operations, U.S. 
Fish and Wildlife Service.
[FR Doc. 2021-13800 Filed 6-30-21; 8:45 am]
BILLING CODE 4333-15-C