Proposed Rule2024-20158
Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Alabama Hickorynut and Threatened Status With Section 4(d) Rule for Obovaria cf. unicolor
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
September 10, 2024
Issuing agencies
Interior DepartmentFish and Wildlife Service
Abstract
We, the U.S. Fish and Wildlife Service (Service), propose to list the Alabama hickorynut (Obovaria unicolor) as an endangered species and the undescribed Obovaria cf. unicolor as a threatened species under the Endangered Species Act of 1973 (Act), as amended. Both species are freshwater mussels. This document also serves as our 12-month finding on a petition to list the Alabama hickorynut. For Obovaria cf. unicolor, we also propose a rule issued under section 4(d) of the Act to provide for the conservation of the species. If we adopt this rule as proposed, it would apply the protections of the Act to these species. We find that designation of critical habitat for both the Alabama hickorynut and Obovaria cf. unicolor is prudent but not determinable at this time.
Full Text
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[Federal Register Volume 89, Number 175 (Tuesday, September 10, 2024)]
[Proposed Rules]
[Pages 73330-73349]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-20158]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2024-0130; FXES111109FEDR-245-FF09E21000]
RIN 1018-BH45
Endangered and Threatened Wildlife and Plants; Endangered Species
Status for the Alabama Hickorynut and Threatened Status With Section
4(d) Rule for Obovaria cf. unicolor
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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[[Page 73331]]
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
list the Alabama hickorynut (Obovaria unicolor) as an endangered
species and the undescribed Obovaria cf. unicolor as a threatened
species under the Endangered Species Act of 1973 (Act), as amended.
Both species are freshwater mussels. This document also serves as our
12-month finding on a petition to list the Alabama hickorynut. For
Obovaria cf. unicolor, we also propose a rule issued under section 4(d)
of the Act to provide for the conservation of the species. If we adopt
this rule as proposed, it would apply the protections of the Act to
these species. We find that designation of critical habitat for both
the Alabama hickorynut and Obovaria cf. unicolor is prudent but not
determinable at this time.
DATES: We will accept comments received or postmarked on or before
November 12, 2024. Comments submitted electronically using the Federal
eRulemaking Portal (see ADDRESSES, below) must be received by 11:59
p.m. eastern time on the closing date. We must receive requests for a
public hearing, in writing, at the address shown in FOR FURTHER
INFORMATION CONTACT by October 25, 2024.
ADDRESSES: You may submit comments by one of the following methods:
(1) Electronically: Go to the Federal eRulemaking Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>. In the Search box, enter FWS-R4-ES-2024-0130,
which is the docket number for this rulemaking. Then, click on the
Search button. On the resulting page, in the panel on the left side of
the screen, under the Document Type heading, check the Proposed Rule
box to locate this document. You may submit a comment by clicking on
``Comment.''
(2) By hard copy: Submit by U.S. mail to: Public Comments
Processing, Attn: FWS-R4-ES-2024-0130, U.S. Fish and Wildlife Service,
MS: PRB/3W, 5275 Leesburg Pike, Falls Church, VA 22041-3803.
We request that you send comments only by the methods described
above. We will post all comments on <a href="https://www.regulations.gov">https://www.regulations.gov</a>. This
generally means that we will post any personal information you provide
us (see Information Requested, below, for more information).
Availability of supporting materials: Supporting materials, such as
the species status assessment report, are available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> under Docket No. FWS-R4-ES-2024-0130.
FOR FURTHER INFORMATION CONTACT: Bill Pearson, Field Supervisor, U.S.
Fish and Wildlife Service, Alabama Ecological Services Field Office,
1208 Main Street, Daphne, AL 36526; telephone 251-441-5870. Individuals
in the United States who are deaf, deafblind, hard of hearing, or have
a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access
telecommunications relay services. Individuals outside the United
States should use the relay services offered within their country to
make international calls to the point-of-contact in the United States.
Please see Docket No. FWS-R4-ES-2024-0130 on <a href="https://www.regulations.gov">https://www.regulations.gov</a> for a document that summarizes this rulemaking.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Act (16 U.S.C. 1531 et
seq.), a species warrants listing if it meets the definition of an
endangered (in danger of extinction throughout all or a significant
portion of its range) or a threatened species (likely to become an
endangered species within the foreseeable future throughout all or a
significant portion of its range). If we determine that a species
warrants listing, we must list the species promptly and designate the
species' critical habitat to the maximum extent prudent and
determinable. We have determined that the Alabama hickorynut meets the
Act's definition of an endangered species and that Obovaria cf.
unicolor meets the Act's definition of a threatened species; therefore,
we are proposing to list them accordingly. Listing a species as an
endangered species or a threatened species can be completed only by
issuing a rule through the Administrative Procedure Act rulemaking
process (5 U.S.C. 551 et seq.).
What this document does. We propose to list the Alabama hickorynut
as an endangered species, and we propose to list Obovaria cf. unicolor
as a threatened species with a rule issued under section 4(d) of the
Act (a ``4(d) rule'').
The basis for our action. Under the Act, we may determine that a
species is an endangered or threatened species because of any of five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. We have determined that the Alabama hickorynut is
endangered due to the following threats: sedimentation, altered flow
regimes, point and nonpoint source pollution, climate change, direct
and indirect impacts of development and anthropogenic disturbances, and
sea level rise associated with climate change. We have further
determined that Obovaria cf. unicolor is threatened due to the
following threats: sedimentation, altered flow regimes, point and
nonpoint source pollution, climate change, direct and indirect impacts
of development and anthropogenic disturbances, and sea level rise
associated with climate change.
Information Requested
We intend that any final action resulting from this proposed rule
will be based on the best scientific and commercial data available and
be as accurate and as effective as possible. Therefore, we request
comments or information from other governmental agencies, Native
American Tribes, the scientific community, industry, or any other
interested parties concerning this proposed rule. We particularly seek
comments concerning:
(1) The species' biology, range, and population trends, including:
(a) Biological or ecological requirements of the species, including
habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns
and the locations of any additional populations of these species;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for these species, their
habitats, or both.
(2) Threats and conservation actions affecting these species,
including:
(a) Factors that may be affecting the continued existence of these
species, which may include habitat modification or destruction,
overutilization, disease, predation, the inadequacy of existing
regulatory mechanisms, or other natural or manmade factors;
(b) Biological, commercial trade, or other relevant data concerning
any threats (or lack thereof) to these species; and
(c) Existing regulations or conservation actions that may be
addressing threats to these species.
(3) Additional information concerning the historical and current
status of these species.
[[Page 73332]]
(4) Information to assist with applying or issuing protective
regulations under section 4(d) of the Act that may be necessary and
advisable to provide for the conservation of the Obovaria cf. unicolor.
In particular, we seek information concerning:
(a) The extent to which we should include any of the Act's section
9 prohibitions in the 4(d) rule; and
(b) Whether we should consider any additional or different
exceptions from the prohibitions in the 4(d) rule.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Please note that submissions merely stating support for, or
opposition to, the action under consideration without providing
supporting information, although noted, do not provide substantial
information necessary to support a determination. Section 4(b)(1)(A) of
the Act directs that determinations as to whether any species is an
endangered or a threatened species must be made solely on the basis of
the best scientific and commercial data available.
You may submit your comments and materials concerning this proposed
rule by one of the methods listed in ADDRESSES. We request that you
send comments only by the methods described in ADDRESSES.
If you submit information via <a href="https://www.regulations.gov">https://www.regulations.gov</a>, your
entire submission--including any personal identifying information--will
be posted on the website. If your submission is made via a hardcopy
that includes personal identifying information, you may request at the
top of your document that we withhold this information from public
review. However, we cannot guarantee that we will be able to do so. We
will post all hardcopy submissions on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Comments and materials we receive, as well as supporting
documentation we used in preparing this proposed rule, will be
available for public inspection on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Our final determinations may differ from this proposal because we
will consider all comments we receive during the comment period as well
as any information that may become available after this proposal. Based
on the new information we receive (and, if relevant, any comments on
that new information), we may conclude that one or both species are a
different status, or we may conclude that one or both species do not
warrant listing as either an endangered species or a threatened
species. In addition, for Obovaria cf. unicolor, we may change the
parameters of the prohibitions or the exceptions to those prohibitions
in the protective regulations under section 4(d) of the Act if we
conclude it is appropriate in light of comments and new information
received. For example, we may expand the prohibitions if we conclude
that the protective regulation as a whole, including those additional
prohibitions, is necessary and advisable to provide for the
conservation of the species. Conversely, we may establish additional or
different exceptions to the prohibitions in the final rule if we
conclude that the activities would facilitate or are compatible with
the conservation and recovery of the species. In our final rule, we
will clearly explain our rationale and the basis for our final
decisions, including why we made changes, if any, that differ from this
proposal.
Public Hearing
Section 4(b)(5) of the Act provides for a public hearing on this
proposal, if requested. Requests must be received by the date specified
in DATES. Such requests must be sent to the address shown in FOR
FURTHER INFORMATION CONTACT. We will schedule a public hearing on this
proposal, if requested, and announce the date, time, and place of the
hearing, as well as how to obtain reasonable accommodations, in the
Federal Register and local newspapers at least 15 days before the
hearing. We may hold the public hearing in person or virtually via
webinar. We will announce any public hearing on our website, in
addition to in the Federal Register. The use of virtual public hearings
is consistent with our regulations at 50 CFR 424.16(c)(3).
Previous Federal Actions
In April 2010, the Alabama hickorynut was included in a petition
from the Center for Biological Diversity and others (CBD 2010, entire)
requesting that the Service list 404 aquatic, riparian, and wetland
species as endangered or threatened species under the Act. In response
to the petition, on September 27, 2011, the Service published in the
Federal Register (76 FR 59836) a partial 90-day finding in which we
announced our finding that the petition contained substantial
information indicating that listing may be warranted for numerous
species, including the Alabama hickorynut.
On February 27, 2020, the Center for Biological Diversity filed a
lawsuit against the Service, alleging, among other claims, that the
Service violated the Act (16 U.S.C. 1533(b)(3)(B)) by delaying the 12-
month finding for the listing of the Alabama hickorynut. The parties
entered a settlement agreement on July 24, 2023, in which the Service
committed to submit the 12-month finding to the Federal Register by
September 2, 2024. This document complies with the settlement
agreement.
We note that the April 2010 petition specified an accepted range
for the Alabama hickorynut of the eastern Gulf Coast drainages of the
Mobile River Basin, the Pascagoula River drainage, the Pearl River
drainage, and the Lake Pontchartrain drainages. However, as discussed
below under I. Proposed Listing Determination, Background, preliminary
data support that Alabama hickorynut (Obovaria unicolor) is found only
in the Mobile River Basin, and the individuals from the other three
drainages are a distinct species still undescribed, Obovaria cf.
unicolor. Because the Alabama hickorynut was petitioned with the
accepted range including all four drainages and because the genetic
analysis distinguishing two distinct species is still unpublished, we
evaluated the Alabama hickorynut and the undescribed species throughout
the entire accepted petitioned range.
Peer Review
A species status assessment (SSA) team prepared an SSA report for
Alabama hickorynut, including the undescribed Obovaria cf. unicolor.
The SSA team was composed of Service biologists, in consultation with
other species experts. The SSA report represents a compilation of the
best scientific and commercial data available concerning the status of
the species, including the impacts of past, present, and future factors
(both negative and beneficial) affecting the species.
In accordance with our joint policy on peer review published in the
Federal Register on July 1, 1994 (59 FR 34270), and our August 22,
2016, memorandum updating and clarifying the role of peer review in
listing and recovery actions under the Act, we solicited independent
scientific review of the information contained in the SSA report for
the Alabama hickorynut and Obovaria cf. unicolor. We sent the SSA
report to five independent peer reviewers and received no responses.
I. Proposed Listing Determination
Background
The SSA report (Service 2023, pp. 9-16) presents a thorough review
of the taxonomy, life history, and ecology of the Alabama hickorynut
(Obovaria unicolor) and Obovaria cf. unicolor.
Species taxonomic status remains unclear for the Alabama
hickorynut.
[[Page 73333]]
Genetics data support Alabama hickorynut (Obovaria unicolor) as a
Mobile River Basin endemic and the individuals of the western drainages
(Pascagoula, Pearl, and Pontchartrain) comprising a distinct species
yet to be formally described, Obovaria cf. unicolor (Inoue et al. 2013,
pp. 2670-2683). Genetics work by the U.S. Geological Survey (USGS) is
upcoming to resolve the taxonomic uncertainty. In the SSA report, we
evaluated both the Alabama hickorynut and Obovaria cf. unicolor because
the petitioned entity included the entire range of both species and
because Obovaria cf. unicolor has not yet been formally described. Both
species have a lifespan of 20 to 44 years. The two entities are
allopatric, meaning they occur in separate, non-overlapping
geographical areas. In the SSA report, we have assumed similarities
between the two species in biology and ecology, but we have assessed
their differences in geographic occupancy and threats faced.
The Alabama hickorynut (Obovaria unicolor) has a generally round to
oval shape with a moderately thick shell. The species is moderately
inflated and grows up to a length of 50 to 70 millimeters (mm). Males
grow to be slightly larger than females (Haag and Rypel 2011, pp. 225-
247). Posterior and anterior margins are rounded. The umbo is inflated
and elevated above the hinge line (Williams et al. 2008, pp. 476-477;
Haag, from Mirarchi et al. 2004, p. 99). The lateral teeth are short
and straight. The pseudocardinal teeth are triangular and erect with
two divergent teeth in the left valve and one in the right valve. The
nacre inside the shell is usually white but occasionally pink (Williams
et al. 2008, pp. 476-477). Obovaria cf. unicolor has yet to be formally
described, but has a similar morphology to Alabama hickorynut.
The Alabama hickorynut and Obovaria cf. unicolor occupy large
creeks and streams to large rivers with sand, gravel, and silt
substrates in slow to moderate current (Williams et al. 2008, p. 477;
Mirarchi et al. 2004, p. 99). Historically, the Alabama hickorynut
occupied the mainstem of the Tombigbee and Alabama Rivers along with
their associated large tributaries. Obovaria cf. unicolor historically
occupied the mainstem and associated large tributaries of the
Pascagoula, Pearl, Tangipahoa, Tickfaw, and Amite Rivers. Occurrence
data collected over time indicate that both species were historically
found in low densities and were relatively rare in mussel assemblages.
The Alabama hickorynut and Obovaria cf. unicolor have complex life
cycles that rely on fish hosts for successful reproduction, similar to
other mussels. Both species are long-term brooders, gravid from August
to the following June, with glochidia being fully developed by November
(Haag and Warren 2003, p. 83). Several host fish species have been
documented for the Alabama hickorynut and Obovaria cf. unicolor, and
all host fishes appear to be relatively common species of darters
(Percidae) of the genera Ammocrypta, Etheostoma, and Percina.
Regulatory and Analytical Framework
Regulatory Framework
Section 4 of the Act (16 U.S.C. 1533) and the implementing
regulations in title 50 of the Code of Federal Regulations set forth
the procedures for determining whether a species is an endangered
species or a threatened species, issuing protective regulations for
threatened species, and designating critical habitat for endangered and
threatened species.
The Act defines an ``endangered species'' as a species that is in
danger of extinction throughout all or a significant portion of its
range, and a ``threatened species'' as a species that is likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range. The Act requires that we
determine whether any species is an endangered species or a threatened
species because of any of the following factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
These factors represent broad categories of natural or human-caused
actions or conditions that could have an effect on a species' continued
existence. In evaluating these actions and conditions, we look for
those that may have a negative effect on individuals of the species, as
well as other actions or conditions that may ameliorate any negative
effects or may have positive effects.
We use the term ``threat'' to refer in general to actions or
conditions that are known to or are reasonably likely to negatively
affect individuals of a species. The term ``threat'' includes actions
or conditions that have a direct impact on individuals (direct
impacts), as well as those that affect individuals through alteration
of their habitat or required resources (stressors). The term ``threat''
may encompass--either together or separately--the source of the action
or condition or the action or condition itself.
However, the mere identification of any threat(s) does not
necessarily mean that the species meets the statutory definition of an
``endangered species'' or a ``threatened species.'' In determining
whether a species meets either definition, we must evaluate all
identified threats by considering the species' expected response and
the effects of the threats--in light of those actions and conditions
that will ameliorate the threats--on an individual, population, and
species level. We evaluate each threat and its expected effects on the
species, then analyze the cumulative effect of all of the threats on
the species as a whole. We also consider the cumulative effect of the
threats in light of those actions and conditions that will have
positive effects on the species, such as any existing regulatory
mechanisms or conservation efforts. The Secretary determines whether
the species meets the definition of an ``endangered species'' or a
``threatened species'' only after conducting this cumulative analysis
and describing the expected effect on the species.
The Act does not define the term ``foreseeable future,'' which
appears in the statutory definition of ``threatened species.'' Our
implementing regulations at 50 CFR 424.11(d) set forth a framework for
evaluating the foreseeable future on a case-by-case basis, which is
further described in the 2009 Memorandum Opinion on the foreseeable
future from the Department of the Interior, Office of the Solicitor (M-
37021, January 16, 2009; ``M-Opinion,'' available online at <a href="https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf">https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf</a>).
The foreseeable future extends as far into the future as the U.S. Fish
and Wildlife Service and National Marine Fisheries Service (hereafter,
the Services) can make reasonably reliable predictions about the
threats to the species and the species' responses to those threats. We
need not identify the foreseeable future in terms of a specific period
of time. We will describe the foreseeable future on a case-by-case
basis, using the best available data and taking into account
considerations such as the species' life-history characteristics,
threat projection timeframes, and environmental variability. In other
words, the foreseeable future is the period of time over which we can
make reasonably
[[Page 73334]]
reliable predictions. ``Reliable'' does not mean ``certain''; it means
sufficient to provide a reasonable degree of confidence in the
prediction, in light of the conservation purposes of the Act.
Analytical Framework
The SSA report documents the results of our comprehensive
biological review of the best scientific and commercial data regarding
the status of the species, including an assessment of the potential
threats to the species. The SSA report does not represent our decision
on whether the species should be proposed for listing as endangered or
threatened species under the Act. However, it does provide the
scientific basis that informs our regulatory decisions, which involve
the further application of standards within the Act and its
implementing regulations and policies.
To assess the viability of Alabama hickorynut and Obovaria cf.
unicolor, we used the three conservation biology principles of
resiliency, redundancy, and representation (Shaffer and Stein 2000, pp.
306-310). Briefly, resiliency is the ability of the species to
withstand environmental and demographic stochasticity (for example, wet
or dry, warm or cold years), redundancy is the ability of the species
to withstand catastrophic events (for example, droughts, large
pollution events), and representation is the ability of the species to
adapt to both near-term and long-term changes in its physical and
biological environment (for example, climate conditions, pathogens). In
general, species viability will increase with increases in resiliency,
redundancy, and representation (Smith et al. 2018, p. 306). Using these
principles, we identified the species' ecological requirements for
survival and reproduction at the individual, population, and species
levels, and described the beneficial and risk factors influencing the
species' viability.
The SSA process can be categorized into three sequential stages.
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical
and current condition of the species' demographics and habitat
characteristics, including an explanation of how each species arrived
at its current condition. The final stage of the SSA involved making
predictions about the species' responses to positive and negative
environmental and anthropogenic influences. Throughout all of these
stages, we used the best available information to characterize
viability as the ability of a species to sustain populations in the
wild over time, which we then used to inform our regulatory decision.
The following is a summary of the key results and conclusions from
the SSA report; the full SSA report can be found at Docket No. FWS-R4-
ES-2024-0130 on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Summary of Biological Status and Threats
In this discussion, we review the biological conditions of the
species and their resources, and the threats that influence the
species' current and future conditions, in order to assess each
species' overall viability and the risks to that viability.
Population and Species Needs
The individual, population-level, and species-level needs of the
species are summarized below in table 1. For additional information,
please see the SSA report (Service 2023, pp. 19-20). Briefly, for
populations to be sufficiently resilient, they must have adequate water
quality, natural flow regimes, stable habitat, and substrates on a
larger scale. Connectivity is also an important factor for populations
because it facilitates gene flow within and among populations, thereby
promoting adaptive potential, and it enables movement and dispersal of
individuals to suitable habitat. Natural flow regimes are an important
resource need for Alabama hickorynut and Obovaria cf. unicolor
populations as flows are a habitat requirement for all life stages.
More specifically, the species require flowing water for sheltering
(habitat requirement), feeding, reproduction, and dispersal. Altered
flow regimes may thus cause decreased spawning, recruitment, and
survival. Adequate water quality is a need at the individual level for
sheltering, reproduction, and feeding (to ensure food source is
present). Stable habitat, and in particular the presence of stable
sand, gravel, and silt substrates, is an important resource need for
sheltering and feeding, especially for juveniles and adults due to
their limited movement and dispersal abilities during these life
stages. At the species level, both species need a sufficient number and
distribution of healthy populations to withstand environmental and
demographic stochasticity (resiliency), withstand catastrophes
(redundancy), and adapt to biological and physical changes in their
environment (representation). Genetic diversity should be high enough
that the species will be able to adapt to changing environmental
factors through the process of natural selection.
Table 1--Summary of the Individual Resource Needs by Life Stage of the Alabama Hickorynut (Obovaria unicolor)
and Obovaria cf. unicolor
----------------------------------------------------------------------------------------------------------------
Life stage Resources needed
----------------------------------------------------------------------------------------------------------------
Fertilized Eggs........................... <bullet> Mature males upstream from mature females.
<bullet> Suitable flow.
<bullet> Suitable water quality and quantity.
Glochidia................................. <bullet> Interactions with appropriate host fish.
<bullet> Connectivity to suitable habitat for dispersal by fish.
<bullet> Suitable flow.
<bullet> Suitable water quality and quantity for glochidia and host
fish.
Juveniles................................. <bullet> Suitable, stable substrate.
<bullet> Sufficient food availability within sediment.
<bullet> Sufficient water flow.
<bullet> Suitable water quality and quantity.
Adults.................................... <bullet> Suitable, stable substrate.
<bullet> Sufficient food availability in water column.
<bullet> Suitable flow.
<bullet> Suitable water quality and quantity.
----------------------------------------------------------------------------------------------------------------
[[Page 73335]]
Summary of Threats
To assess the status of the Alabama hickorynut and Obovaria cf.
unicolor, we first examined the following influences on viability in
our SSA analysis: sedimentation; altered flow regimes; point and
nonpoint source pollution, which come from a variety of sources,
including urbanization, agriculture, forestry, and mining; and a
constricted range and reduced connectivity from impoundments (Service
2023, p. 21). We then determined which influences were most significant
for viability of both the species, then modeled those influences and
carried them forward in our analysis. Those influences include: habitat
loss, degradation, and fragmentation (Factor A); water quality
degradation (Factor A); altered flow regimes (Factor A); sedimentation
from land use (Factor A); the influences of climate change on stream
flow, water temperature, and sea level rise (Factor E); and their
cumulative effects. We summarize these threats, as well as their
sources and the responses of the Alabama hickorynut and Obovaria cf.
unicolor to those threats, below. For a detailed description of threats
that may influence the viability of both species, please refer to
chapter 4 of the SSA report (Service 2023, pp. 21-36).
Sedimentation
Sedimentation due to a variety of sources, including agriculture,
forestry practices, urbanization, bank erosion, and gravel mining, is
considered a stressor to Alabama hickorynut and Obovaria cf. unicolor
throughout their ranges. Sediment is composed of both organic
(biological material) and inorganic (sand, silt, clay) particulate
matter formed through various processes including weathering, wind/
wave/ice action, and tectonic uplift (Perkins et al. 2022, p. 2).
Sediment is listed as the most common pollutant in rivers, streams,
lakes, and reservoirs and is estimated to cause approximately $16
billion in damage every year (EPA 2005, pp. 9-25; Du Plessis 2019, pp.
86-87). While all streams carry some sediment, aquatic ecosystems are
negatively affected if sediment loads are excessive enough to alter
channel formation, stream productivity, or both.
River channel erosion, precipitation runoff, and wind transport
account for 30 percent of the total sediment load in aquatic systems,
while land-use activities such as agriculture (Peacock et al. 2005, p.
548), logging (Beschta 1978, entire), mining (Seakem Group et al. 1992,
p. 17), urbanization (Guy and Ferguson 1963, entire), and hydrological
alteration (Hastie et al. 2001, entire) account for the remaining 70
percent (Du Plessis 2019, pp. 86-87). Agricultural activities have been
found to produce the most significant amount of sedimentation (e.g.,
livestock grazing/trampling near water's edge; Nolte et al. 2013, p.
296).
Increased sedimentation may result in decreases in feeding and
respiration, which could result in negative alterations to mussel's
energetic metabolism and growth (Dimock and Wright 1993, p. 183; La
Peyre et al. 2019, p. 5). Specifically, as sedimentation increases,
clearance rates (i.e., volume of water completely cleared of particles
per unit time) decrease and pseudofeces (i.e., waste) increase to
prevent gill filaments from clogging (Bayne and Newell 1983, entire;
Madon et al. 1998, p. 401). If the stressor becomes long-term, mussels
may find feeding to be outweighed by the energetic cost of sorting food
vs. non-food material, decreasing the individual's body condition
(Bayne and Widdows 1978, p. 137; Madon et al. 1998, p. 401).
Increased sedimentation is expected to interfere with mussel-host
fish interaction, further impacting the reproductive success of mussels
due to physical abrasion of the host fish's gills or decreased
visibility within the water column. Successful glochidial attachment
and metamorphosis has been found to be reduced at concentrations
ranging from 1,250 to 5,000 milligrams per liter (mg/L) of
montmorillonite clay in the water column (Beussink et al. 2007, pp. 15-
17). This reduction is attributed to physical abrasion of fish gill
tissues from increased suspended sediment; increased fish mucus
production in attempt to protect the gill from physical abrasion;
coughing, which may dislodge glochidia from the gills; or declines in
keratocytes (i.e., wound-healing cells), which would harm glochidia's
ability to encapsulate (Beussink et al. 2007, pp. 15-17).
Dams and Impoundments
The detrimental effects of impoundments and dams on aquatic
habitats and freshwater mussels are relatively well-documented (Watters
1999, p. 261). Increased demand for transportation, power, and water
needs in the 1920s and 1930s led to rapid industrialization (Haag 2012,
p. 329). Currently, there are an estimated 3,404 dams within the Mobile
River basin. More than 1,000 miles of small and large river habitat in
the Mobile River drainage have been impounded for navigation, flood
control, water supply, and/or hydroelectric production purposes (58 FR
14330 at 14335, March 17, 1993). These impoundments kill riverine
mussels during construction and dredging, suffocate them by
accumulating sediments, lower food and oxygen availability for the
mussels by the reducing water flow, and cause local extirpation of host
fish. Within the eastern United States, extinction and/or extirpation
of native freshwater mussels has been attributed to impoundment and
inundation of riffle habitats in all major river basins (Haag 2008 p.
107; Neves et al. 1997, p. 63).
After a dam is installed and reservoir created, the aquatic habitat
typically accumulates more silt, loses shallow water habitat, decreases
in water flow, accumulates more pollutants (adhered to sediment
particles), and overall accumulates more nutrient-poor water (due to
decaying algae within the reservoir, which depletes dissolved oxygen)
(Watters 1999, p. 261). Typically, mussels are abundant in shallower
waters and cannot tolerate impoundment depths and temperatures or
fluctuating conditions found in tailwaters of dams (Fagin 2020, p. 2).
Further, impoundments become sediment traps, which may increase the
chance of smothering and decrease species' interactions with host fish.
Mussels living in the tailwaters may experience fluctuations in
temperatures and water levels (Watters 1999, p. 262). These
fluctuations may expose individuals to dewatering events and/or
excessively warm- or cold-water temperatures (Watters 1999, p. 262).
Ultimately, the survival and overall reproductive success of mussels is
influenced both upstream and downstream of dams.
Within the range of Obovaria cf. unicolor, plans for a new
reservoir on the Pearl River downstream of Ross Barnett Reservoir near
Jackson, Mississippi, are under consideration (Lindeman 2013, pp. 202-
203). Of particular note is the proposed One Lake project, which
includes a new dam and commercial development area 9 miles (14.5
kilometers) south of the current Ross Barnett Reservoir Dam near
Interstate 20. The intent of the One Lake project is to dredge the
Pearl River in order to widen, deepen, and straighten an additional 10
miles (16.1 kilometers) of waterway for flood control protection and
commercial development opportunities. The One Lake project is still
being debated, and the project's future is uncertain. If the One Lake
project is implemented, it will likely alter the hydrologic regime and
geomorphology of the Pearl River (similar to how the construction of
Ross
[[Page 73336]]
Barnett Reservoir altered the system in the 1960s). This potential
altered regime could increase channel instability and erosion through
drastic changes in water outflows at dams, which can lead to bank
collapse.
Also within the range of Obovaria cf. unicolor, plans for new
reservoirs on Big Cedar Creek in the Pascagoula River drainage have
been proposed in the past as the Lake George Project; however, the
current status of the project is unknown. If the Lake George project is
implemented, it will likely alter the hydrologic regime and
geomorphology of the Big Cedar Creek and subsequently the Pascagoula
River. This potential altered regime could lead to increased channel
instability.
Channelization
Channelization activities profoundly alter riverine habitats by
reducing habitat heterogeneity and aquatic diversity (Ebert 1993, p.
157; Watters 1999, p. 268). These activities affect many physical
characteristics of streams through accelerated erosion (i.e.,
headcutting), increased bedload (sediment that moves along the
streambed), reduced depth, decreased habitat diversity, geomorphic
instability (channel modification and subsequent instability), and
riparian canopy loss (Hartfield 1993, p. 139). Further, changes in
water velocity and depth associated with channelization increase
turbulence and suspended sediments. These impacts contribute to loss of
habitat for the Alabama hickorynut and Obovaria cf. unicolor, as well
as interfere with gravid female host-fish interactions.
One of the largest water development projects within the United
States, the Tennessee-Tombigbee Waterway (TTW) in Alabama and
Mississippi is within the Alabama hickorynut's range. While the project
was authorized in 1946, the TTW did not begin construction until 1972.
The TTW constructed to provide more direct access from the Tennessee
River to the Gulf of Mexico, was completed in 1984 and includes 10 lock
and dams as well as 377 km of channelization (Haag 2012, p. 330). This
project significantly altered the Tombigbee River, which had been the
last free-flowing, unpolluted, diverse stream systems within the Mobile
Basin, into a series of artificial canals and reservoirs. The
construction of the TTW has significantly negatively impacted the
Alabama hickorynut's range and abundance by rendering the majority of
the mainstem of the Tombigbee River inhospitable to the Alabama
hickorynut. The impacts of this channelization are ongoing.
No other new channelization projects are on the horizon; however,
the U.S. Army Corps of Engineers (USACE) is undergoing planning efforts
to improve navigation in the TTW, which will include deepening the
channel. Because the underlying geology is particularly sensitive to
disturbance, further bed instability is likely throughout the channel
and downstream without effective planning and designs to prevent head-
cuts.
Dredging and channelization of fluvial (flowing water) systems
include the widening and deepening of stream channels, which increases
channel capacity, shortens stream length, and increases stream gradient
(Pierce and King 2013, p. 223). These activities allow greater volumes
of water to move through the system at a faster rate; however, they
also hydrologically disconnect river channels from the adjacent
floodplain. Within the southeastern United States, channelization has
been used for navigation and to reduce flooding, and it is likely even
more extensive than damming (Haag 2012, p. 330).
Channels dredged for navigation or flood control will eventually
begin to refill with material. To ensure minimum depth, the channel is
often periodically re-dredged. Subsequent dredge spoil (i.e.,
unconsolidated mixed sediment composed of rock, soil, and/or shell
material) and contaminants associated with the waste are often
deposited in upland areas (Watters 1999, p. 268). Over time, this waste
may re-enter the water via surface runoff, biological uptake and
cycling, and/or leaching into groundwater (Watters 1999, p. 268), and
may subsequently affect the Alabama hickorynut and Obovaria cf.
unicolor directly or may affect their habitats.
Gravel Mining
The Alabama hickorynut and Obovaria cf. unicolor are not found in
impounded waters and are intolerant of lentic (standing water) habitats
that may be formed by gravel mining or other landscape-altering
practices. Incompatible sand and gravel mining, with its disruption of
topography, vegetation, and flow pattern of streams, is considered a
major stressor to the Bogue Chitto River in the Pearl River drainage
where Obovaria cf. unicolor occurs (TNC 2004, p. 16). Although
Louisiana has reduced the number of gravel mining permits issued,
mining in the floodplain continues to be a significant threat to
Obovaria cf. unicolor in that state.
In Obovaria cf. unicolor's range in the Pascagoula River drainage,
the results of historical sand and gravel dredging impacts have been a
concern for the Bouie and Leaf Rivers (Mississippi Department of
Environmental Quality (MDEQ) 2000, pp. 1-98) Historically, the American
Sand and Gravel Company (1995, p. B4) has mined sand and gravel using a
hydraulic suction dredge, operating within the banks or adjacent to the
Bouie and Leaf Rivers. Large gravel bars of the river and its
floodplain were removed over a period of 50 years, creating open-water
areas that function as deep lake systems (American Sand and Gravel
Company 1995, pp. B4-B8). The creation of these large, open-water areas
has accelerated geomorphic processes, specifically headcutting
(erosional feature causing an abrupt drop in the streambed) that has
adversely affected the flora and fauna of many coastal plain streams
(Patrick et al. 1993, p. 90). The infilling of these gravel pits and
their downstream effects back to a natural riverine state is predicted
to take hundreds of years (Grimball and Heitmuller 2012, p. 158).
Mining in active river channels typically results in incision upstream
of the mine by knickpoints (breaks in the slope of a river or stream
profile caused by renewed erosion attributed to a bottom disturbance
that may retreat upstream), sediment deposition downstream, and an
alteration in channel morphology that can have impacts for years (Mossa
and Coley 2004, pp. 1-20). The upstream migration of knickpoints, or
headcutting, may cause undermining of structures, lowering of alluvial
water tables (aquifer comprising unconsolidated materials deposited by
water and typically adjacent to rivers), channel destabilization and
widening, and loss of aquatic and riparian habitat. This geomorphic
change may cause the extirpation of riparian and lotic (flowing water)
species (Patrick et al. 1993, p. 96).
Contaminants
Metals--Freshwater mussels are one of the most sensitive species to
metals, ammonia, and ion constituents including copper, alachlor (i.e.,
an herbicide), nickel, chloride, sulfate, zinc, and potassium (Wang et
al. 2017, p. 1). Despite limited research, data indicate mussels
representing different families or tribes have similar sensitivities to
most chemicals, regardless of mode of toxic exposure (Wang et al. 2017,
p. 1). This information indicates thresholds identified for other
freshwater mussels can be used to infer the response of the Alabama
hickorynut and Obovaria cf. unicolor.
[[Page 73337]]
Metals naturally occur in aquatic ecosystems and are primarily
introduced to waterways due to weathering of rocks, soil erosion, and/
or dissolution of water-soluble salts (Garbarino et al. 1995, p. 1).
While naturally occurring metals often move through aquatic ecosystems
without detrimental effects to aquatic biota, this is not necessarily
the case with anthropogenic sources of metals. Industrial and forestry
activities within the region that do not employ best management
practices (BMPs) and directly discharge into river systems
significantly increase heavy metal loads (Suryawanshi 2017, p. 625;
Uttermann et al. 2019, p. 200). As a result, river systems that are
habitat for the Alabama hickorynut and Obovaria cf. unicolor may have
metal contamination, which may negatively impact the species; however,
we do not have specific data about the streams the two species
inhabits.
Nutrients and ions--The southeastern United States is affected by
intense pressures of fossil fuel mining, urban development/sprawl,
agricultural and forestry practices, and increasing demands for fresh
water (Archambault et al. 2017, p. 395). Runoff associated with these
practices when BMPs are not employed (i.e., fertilizers, pesticides,
industrial and wastewater effluents, mining discharge, and sediment)
increases nutrient and ion concentrations in waterways that (depending
on magnitude and duration) may exceed freshwater mussel thresholds
(Salerno et al. 2020, pp. 1-2).
Climate Change
Climate change has the potential to increase vulnerability of the
Alabama hickorynut and Obovaria cf. unicolor to catastrophic events or
to alter habitat suitability (e.g., water temperature, dissolved
oxygen, sea level rise) within the species' range. Over the years,
climate change impacts (impaired waters and reduced water supply
security) have been reportedly more frequent and intense
(Intergovernmental Panel on Climate Change (IPCC) 2022, p. 1931).
Extreme heat and precipitation trends have altered ecosystem processes
(e.g., freshwater cycling). Further, projected droughts will become
more intense because of higher temperatures, and the progressive loss
of seasonal water storage will lead to lower summer stream flows (IPCC
2022, p. 1932). Population growth and agricultural activities are
expected to continue to place high demands on the water supply within
the range of the species, impacting stream flow. These lower stream
flows may negatively impact the Alabama hickorynut and Obovaria cf.
unicolor.
Conservation Efforts and Regulatory Mechanisms
Most of the land within the ranges of the Alabama hickorynut and
Obovaria cf. unicolor is privately owned, with some exceptions. The
Alabama hickorynut currently occupies 58 protected river miles of
habitat in the Buttahatchee River, 28 protected river miles in the
Sipsey River, and 30 protected river miles of the Noxubee River, all of
which are tributaries to the Tombigbee River. The protected land of the
Buttahatchee is Wildlife Mississippi property and the Sam R. Murphy
Wildlife Management Area. In the Sipsey River, the protected land is
State-owned Forever Wild land, and in the Noxubee River, the protected
land is federally owned as the Sam D. Hamilton Noxubee National
Wildlife Refuge.
For Obovaria cf. unicolor, there are currently occupied protected
lands in the Pascagoula River system and in the Pearl River system. In
the Pascagoula River system, there are a total of 113 protected river
miles, most of which are within the Pascagoula Wildlife Management Area
(WMA) in the Pascagoula River, Black Creek, and Red Creek. The Nature
Conservancy protects 7 river miles of currently occupied habitat in the
Chickasawhay River, and there are 16 river miles protected on the Leaf
River by the Camp Shelby and Mississippi Land Trust and the Mississippi
River Trust. In the Pearl River system, there are a total of 69
protected river miles that are currently occupied. Three river miles
are protected in the upper Pearl River as Wildlife Mississippi
property, and 66 river miles are protected on the lower Pearl River as
the Bogue Chitto National Wildlife Refuge.
Neither Alabama hickorynut or Obovaria cf. unicolor are protected
under state laws. However, some streams that are occupied by the
species have water quality protections in place. The Clean Water Act of
1972 (33 U.S.C. 1251 et seq.) regulates dredge and fill activities that
would adversely affect streams and wetlands. Such activities are
commonly associated with dry land projects for development, flood
control, and land clearing, as well as for water-dependent projects
such as docks/marinas and maintenance of navigational channels. The
USACE and the Environmental Protection Agency (EPA) share the
responsibility for implementing the permitting program under section
404 of the Clean Water Act. Permit review and issuance follows a
process that encourages avoidance, minimizing and requiring mitigation
for unavoidable impacts to the aquatic environment and habitats. This
includes protecting the riverine habitat occupied by Alabama hickorynut
and Obovaria cf. unicolor. This law has resulted in some enhancement of
water quality and habitat for aquatic life, particularly by reducing
point-source pollutants. For Alabama hickorynut, two occupied waterways
have Total Maximum Daily Loads (TMDLs) established by Alabama
Department of Environmental Management (ADEM) for E. coli: the
Luxapallila River and the Noxubee River. For Obovaria cf. unicolor,
Tallahala Creek in the Pascagoula drainage has a TMDL established by
Mississippi Department of Environmental Quality (MDEQ) for biological
impairment, total nitrogen, pH, and total phosphorous.
Cumulative Effects
We note that, by using the SSA framework to guide our analysis of
the scientific information documented in the SSA report, we have
analyzed the cumulative effects of identified threats and conservation
actions on the species. To assess the current and future condition of
the species, we evaluate the effects of all the relevant factors that
may be influencing the species, including threats and conservation
efforts. Because the SSA framework considers not just the presence of
the factors, but to what degree they collectively influence risk to the
entire species, our assessment integrates the cumulative effects of the
factors and replaces a standalone cumulative-effects analysis.
Current Conditions
Delineating Populations
To assess resiliency of Alabama hickorynut and Obovaria cf.
unicolor populations, we first delineated populations in the most
biologically meaningful way. We based our delineations on occurrence
records through time, on our knowledge of the species' habitat and
resource needs, and on expert input. We determined there to be three
total Alabama hickorynut populations and six total Obovaria cf.
unicolor populations. We also delineated subpopulations for each
species to refine occupancy, influence of threats, and average
abundance. The Alabama hickorynut has 13 subpopulations within its
three populations, and Obovaria cf. unicolor has 16 subpopulations
within its six populations.
[[Page 73338]]
Delineating Representative Units
Representation is the ability of a species to adapt to both near-
term and long-term changes in its physical and biological environment.
Differences in life-history traits, habitat features, and/or genetics
often aid in the delineation of representative units, which are used to
assess species representation. For representative unit delineation, we
consulted with experts in each State and considered differences in
ecological setting and connectivity at a larger scale. Based on the
natural lack of large-scale connectivity, the Alabama hickorynut in the
Mobile River Basin was split into two representative units: Eastern
Mobile River Basin (Alabama and Cahaba Rivers) and Western Mobile River
Basin (Tombigbee River). Obovaria cf. unicolor was divided into five
representative units: the Pascagoula, the Pearl, the Tangipahoa, the
Tickfaw, and the Amite Rivers. The Tangipahoa, Tickfaw, and Amite
Rivers all drain into Lake Pontchartrain, and occurrences extend very
close to the mouth of each river; however, the influence of salt water
in Lake Pontchartrain likely limits any connectivity between these
representative units.
Current Resiliency
Sufficiently resilient populations of the Alabama hickorynut and
Obovaria cf. unicolor should be robust following normal demographic and
environmental stochastic events or disturbances. We assessed the
resilience of each Alabama hickorynut and Obovaria cf. unicolor
population by synthesizing the best available information about habitat
condition and population demographics. Based on the individual and
population needs of the Alabama hickorynut and Obovaria cf. unicolor
(such as adequate water quality/quantity; the presence of stable,
unaltered habitat; and appropriate population size and connectivity to
support reproduction and recruitment within a population), we developed
an approach using key habitat and demographic factors to assess
population resiliency. We assessed two demographic condition parameters
(persistence through time (amount of historical range that is still
currently occupied) and estimated average abundance) and one habitat
condition parameter (amount of altered habitat (impoundment,
channelization, head cutting, etc.)). Based on the Alabama hickorynut's
lifespan, we determined the time period from 2000 to 2023 to represent
the current condition of these species. We ranked subpopulations based
on estimated average abundance by reviewing count data from occurrence
records and using expert elicitation based on the experts' knowledge of
historical numbers. We considered a subpopulation to have a low
abundance if the estimated average count per sample is 0 to 5
individuals. A subpopulation with moderate abundance has an estimated
average count per sample of 6 to 10 individuals, and a subpopulation
with high abundance has an estimated average count of more than 10
individuals.
In order to better facilitate comparisons of current and future
conditions, we categorized resiliency into three levels, as follows:
<bullet> High--population substantially contributes to overall
species viability by having more than 75 percent of its historical
range that is currently occupied, relatively low amounts of altered
habitat, and high abundance.
<bullet> Moderate--population contributes to overall species
viability by having 50-75 percent of its historical range that is
currently occupied, relatively moderate amounts of altered habitat, and
ample abundance.
<bullet> Low--population is likely persisting but also likely does
not contribute to overall species viability because less than 50
percent of its historical range is currently occupied, there is
relatively high amounts of altered habitat, and low abundance.
i. Alabama Hickorynut (Obovaria Unicolor)
Alabama River--There are two subpopulations within the Alabama
River population: mainstem Alabama River and Pine Barren Creek. The
Alabama hickorynut historically occupied at least 233 river miles in
the Alabama River and 11 river miles in Pine Barren Creek. Degradation
and loss of habitat due to impoundment resulted in the extirpation of
this population. Live individuals were last detected in the Alabama
River mainstem in 1999 (Mcgregor et al. 2000, pp. 215-237) and last
detected in Pine Barren Creek in 1917. Our analysis indicated that 100
percent of the Alabama River population's habitat has been altered.
Cahaba River--Historically, Alabama hickorynut occupied 117 river
miles in the Cahaba River, a major tributary to the Alabama River. The
species is now considered extirpated from this system. Surveys from
2000 to present have only detected relic, weathered shells. Seventy-
four river miles of the historical range within the Cahaba River are
altered.
Tombigbee River--The Alabama hickorynut occurred throughout
approximately 1,077 river miles of the mainstem Tombigbee River and
several large tributaries: the Buttahatchee River, the East Fork of the
Tombigbee, the Sucarnoochee River, the Sipsey River, the Black Warrior
River, Luxapallila Creek, the Noxubee River, Lubbub Creek, Trussels
Creek, Tibbee Creek, Bogue Chitto Creek, and Santa Bogue Creek. The
construction of the TTW, which artificially connects the Tennessee
River to the Tombigbee River, has led to the extirpation of many
species from the river's main channel (Bennett et al. 2008, p. 467).
Today, the Alabama hickorynut is considered extirpated from the
mainstem Tombigbee River (approximately 300 river miles) and the Black
Warrior River (approximately 170 river miles) due to impoundment,
dredging, and the creation of the TTW. Most of the tributaries also
experienced a reduction in extant range due to these effects. As
discussed previously, the Alabama hickorynut is naturally a larger
river species, occupying mostly mainstem rivers and then branching out
into larger tributaries of those rivers. In the Tombigbee River system,
the species has lost suitable habitat in the mainstem Tombigbee and is
now isolated to several tributaries. We do not find there is much, if
any, subpopulation connectivity between these tributaries due to the
loss of the connecting mainstem Tombigbee habitat. However,
historically, these units would all have been connected, so we consider
the entire Tombigbee River system one population with 13
subpopulations. Of the 1,077 river miles historically occupied in this
population, only 362 river miles are considered to be currently
occupied, meaning the Alabama hickorynut currently occupies 33.62
percent of its historical range in the Tombigbee population. As a
result, we consider the Tombigbee population to have low resiliency.
Currently, the Alabama hickorynut is extant in seven subpopulations
of the Tombigbee population, and the species is considered extirpated
in six subpopulations. Extant subpopulations are the East Fork of the
Tombigbee, the Buttahatchee River, the Sipsey River, Luxapallila Creek,
Lubbub Creek, the Noxubee River, and the Sucarnoochee River. Although
the species is still extant in those subpopulations, it experienced
range contraction in five of the seven extant subpopulations. All the
extant subpopulations were classified as having low abundance except
for the Sipsey River, which is considered to have high abundance. The
Alabama hickorynut is considered extirpated from the following
subpopulations: the
[[Page 73339]]
mainstem Tombigbee River, Tibbee Creek, Santa Bogue Creek, the Black
Warrior River, Trussels Creek, and Bogue Chitto Creek.
The stronghold for the entire species is in the Sipsey River.
Samples collected from the Sipsey River frequently contain counts of
Alabama hickorynut that are orders of magnitude higher than counts
currently found anywhere else within the species' range. The Sipsey
River supports other rare mussel species that have also experienced
precipitous declines elsewhere within their range in the Mobile River
Basin, including Alabama spike (Elliptio arca), Alabama moccasinshell
(Medionidus acutissimus), and Southern clubshell (Pleurobema decisum),
indicating that the Sipsey River has maintained its ecological
integrity through time (Mirarchi et al. 2004, entire; Williams et al.
2008, entire; Haag and Warren 2010, pp. 655-667). As noted above, the
Sipsey River is the only subpopulation that we consider to have a
``high'' abundance rating.
Alabama Hickorynut: Summary Resiliency Results
Of the three populations of Alabama hickorynut in the Mobile River
Basin, two are considered extirpated (Alabama and Cahaba), and one has
low resiliency (Tombigbee). The species historically has been known to
occur in 1,438 river miles in Alabama and Mississippi in the Mobile
River Basin. The species currently occupies 362 river miles across its
range, meaning it currently occupies 25.17 percent of its historical
range. Overall, resiliency is considered low, meaning the species is
not likely to withstand environmental stochasticity (fire, flood,
storms) or disease and mortality events.
ii. Obovaria cf. Unicolor
Pascagoula River--Obovaria cf. unicolor historically occupied 549
river miles and is presumed to still occupy the full extent of the
river system. The Pascagoula population is divided into five
subpopulations: Pascagoula River, Leaf River, Chickasawhay River, Black
Creek, and Red Creek. The Service surveyed the Pascagoula River for the
species in 2023, and we confirmed current presence with a moderate
abundance level. The other four subpopulations do not have current
records of the species; however, these rivers and creeks have also not
been surveyed recently. A system-wide mussel survey is planned for 2024
by the Mississippi Department of Fish, Wildlife, and Parks (MDWFP). We
still assume presence throughout the entire Pascagoula River system
despite not having current records because the Pascagoula River is
undammed and not impounded, with 0 miles of the species' range altered.
Additionally, 113 river miles of the system are considered protected.
Because we predict the Pascagoula River population occupies all of its
historical range within the river system, the population is considered
to have high resiliency.
Upper Pearl River, above Ross Barnett Reservoir--Above the Ross
Barnett Reservoir in the Pearl River system, Obovaria cf. unicolor
historically occupied 92 river miles within two subpopulations: 27
river miles in the Yockanookany River and 65 river miles in the
mainstem Pearl River. Currently, the species occupies 32 river miles
within this population: 27 river miles in the Yockanookany River and 5
river miles in the mainstem Pearl River.
The Yockanookany River is considered unaltered and 18 river miles
are protected in the Natchez Trace Parkway. Twenty-seven river miles of
the 65 historically occupied river miles of the mainstem Pearl River in
this population are considered altered. Three river miles are in the
mainstem Pearl River are protected by Wildlife Mississippi property.
The species occupies 34.78 percent of its historical range in the upper
Pearl River population. Where found in the upper Pearl population,
Obovaria cf. unicolor is considered to have low abundance.
Therefore, the upper Pearl River population above Ross Barnett
Reservoir is considered to have low resiliency.
Lower Pearl River, below Ross Barnett Reservoir--Of the total 589
river miles historically occupied in the lower Pearl population,
Obovaria cf. unicolor still currently occupies 112 river miles, which
is 19.02 percent of its historical range. Historically, there were
three subpopulations in the Pearl River system below the Ross Barnett
Reservoir; however, the Strong River subpopulation, which historically
occupied 46 river miles, is now considered extirpated. Obovaria cf.
unicolor is extant in the Bogue Chitto River and in the mainstem Pearl
River. All of the historical range in the lower Pearl population has
been altered, and where the species is still found, its abundance is
considered low. The lower Pearl River population below Ross Barnett
Reservoir is considered to have low resiliency.
Tangipahoa River--Obovaria cf. unicolor historically occurred in 78
river miles of the Tangipahoa River and currently occupies 60 river
miles of this system, meaning it occupies 76.92 percent of its
historical range within the Tangipahoa River. Twenty river miles of the
historical range are considered altered. The Tangipahoa River
population is considered to have high resiliency.
Tickfaw River--Obovaria cf. unicolor historically occurred in 44
river miles of the Tickfaw and currently occupies 35 river miles of
this system, meaning it occupies 79.55 percent of its historical range
within the Tickfaw River. The entire historical range within this
population is considered unaltered. The Tickfaw River population is
considered to have high resiliency.
Amite River--Obovaria cf. unicolor historically occurred in 102
river miles of the Amite River but has not been detected in the system
since 1988, so the Amite population is considered extirpated. There are
49 river miles within the historical range that are considered altered.
Obovaria cf. Unicolor: Summary Resiliency Results
Of the six populations of Obovaria cf. unicolor, one population is
considered extirpated (Amite), two populations are considered to have
low resiliency (Upper Pearl and Lower Pearl), and three populations are
considered to have high resiliency (Pascagoula, Tangipahoa, and
Tickfaw). The species historically has been known to occur in 1,454
river miles in Mississippi and Louisiana. The species currently
occupies 788 river miles across its range, meaning it currently
occupies 54.2 percent of its historical range. Overall, Obovaria cf.
unicolor has moderate resiliency.
Current Representation
Representation is the ability of a species to adapt to both near-
term and long-term changes in its physical and biological environment.
The greater the genetic diversity a species has, the more successfully
a species can respond to changing environmental conditions. In the
absence of population-level genetic data for the Alabama hickorynut and
Obovaria cf. unicolor, we considered environmental diversity across
each species' range. The best available data indicate two
representative units (i.e., two major river systems) where the Alabama
hickorynut was historically found, the Alabama River system and the
Tombigbee River system, and four representative units where Obovaria
cf. unicolor is currently found, the Pascagoula River system, the Pearl
River system, the Tangipahoa River, and the Tickfaw River.
Alabama Hickorynut
Of the two representative units for Alabama hickorynut, only one
remains
[[Page 73340]]
extant. The species has been extirpated from the Eastern Mobile River
Basin and now only occupies about 25 percent of its historical range.
Although still extant, the Western Mobile River Basin representative
unit has been left highly fragmented with no connectivity between
subpopulations. The Alabama hickorynut was extirpated from the mainstem
of the Tombigbee because of the TTW. This also eliminated gene flow
between the tributaries of the Tombigbee River. The variety of trend
information available across its range (i.e., loss of populations in
tributaries or major river systems, declines in population extent and
size in portions of the species' range) indicate that the Alabama
hickorynut's overall ability to adapt to changing environmental
conditions is minimal. This is largely due to pervasive human
alteration of habitats, such as the construction and operation of
impoundments. Thus, overall representation for the Alabama hickorynut
is considered low.
Obovaria cf. Unicolor
Of the five representative units for Obovaria cf. unicolor, four
remain extant. The Pearl River unit, though still extant, lost nearly
80 percent of its historical range due to human habitat alteration and
degradation, which exemplifies that like Alabama hickorynut, Obovaria
cf. unicolor also has minimal ability to adapt to changing
environmental conditions. The loss of connectivity is a significant
issue in the Pearl River representative unit. However, Obovaria cf.
unicolor has representative units still spread across its historical
range. One representative unit is considered extirpated, and because
the species has shown that it is intolerant of major environmental
changes (sedimentation, significant changes in water chemistry, habitat
destabilization), we do not expect that the species will return to the
unit without significant efforts to address the identified threats in
this unit. For these reasons, we consider Obovaria cf. unicolor to have
moderate representation.
Current Redundancy
Redundancy refers to the ability of a species to withstand a
catastrophic event. To determine species redundancy, we assess the
species' distribution across its range. The greater the size,
resiliency, and/or number of populations, and the more widely they are
distributed, the greater the likelihood that the species will be able
to withstand and bounce back from a significant loss (e.g., extirpation
of a population) from a catastrophic event.
Alabama Hickorynut
Of the three populations known for Alabama hickorynut, only one,
the Tombigbee River population, remains extant, and this population has
low resiliency. Within the Tombigbee River population, 7 of the 13
subpopulations are still extant. However, all but one of the extant
subpopulations are considered to have low abundance, and two of the
subpopulations span less than 10 river miles within their tributaries,
making them more vulnerable to potential extirpation; the other
subpopulations each span at least 20 river miles. All of the extant
subpopulations face ongoing headcutting, sedimentation, and erosional
issues from surrounding land use practices and dredging operations in
the main channel. Due to the lack of connectivity between
subpopulations, the species' ability to rebound or recolonize areas
after catastrophic events is severely limited. We consider the Alabama
hickorynut to have a low level of redundancy overall because only one
extant population remains with a low level of resiliency.
Obovaria cf. Unicolor
Of the six populations of Obovaria cf. unicolor, one is considered
extirpated and five are extant. Three of the extant populations, the
Pascagoula, the Tangipahoa, and the Tickfaw, are considered to have a
high level of resiliency. The other two extant populations, the upper
Pearl (above Ross Barnett Reservoir) and the lower Pearl (below Ross
Barnett Reservoir), have low resiliency. Although the Tangipahoa and
Tickfaw populations show a high level of resiliency in the current
condition, these two populations represent a small proportion of the
total range of the species. The Tangipahoa population made up 5.4
percent of the species' historical range, and currently makes up 7.6
percent of the species' range. The Tickfaw population made up 3 percent
of the species' historical range, and now makes up 4.4 percent of the
species' range. In contrast, the Pascagoula currently makes up 70
percent of the occupied range and has high resiliency, the lower Pearl
currently makes up 14 percent of the occupied range and has low
resiliency, and the upper Pearl makes up 4 percent of the currently
occupied range and has low resiliency. Overall, we consider Obovaria
cf. unicolor to have moderate redundancy.
Future Conditions
As a part of the SSA, we considered multiple future influences and
projected responses by Alabama hickorynut and Obovaria cf. unicolor.
Because we determined that the current condition of Alabama hickorynut
is consistent with an endangered status (see Determination of Alabama
hickorynut Status, below), we are not presenting the results of the
future scenarios for Alabama hickorynut in this proposed rule. Below.
we present the results for Obovaria cf. unicolor. Please refer to the
SSA report (Service 2023, pp. 51-55) for the full analysis of future
scenarios for both species. Obovaria cf. unicolor is most susceptible
to climate change, sea level rise, and destruction and/or modification
of habitat. We developed multiple future scenarios to capture the range
of uncertainties regarding sea level rise and the projected responses
by Obovaria cf. unicolor.
Climate Change
Climate change predictions under all scenarios are likely to
exacerbate the currently declining trend of Obovaria cf. unicolor. Most
climate change models predict an increase in extreme weather events,
such as droughts and heavy precipitation (IPCC 2022 p. 15), and they
project that average annual temperatures will increase, cold days will
become less frequent, the freeze-free season will lengthen by up to a
month, temperatures exceeding 95 degrees Fahrenheit ([deg]F) will
increase, and heat waves will become longer (Ingram et al. 2013, p. 32;
IPCC 2021, entire). Since the 1970s, moderate to severe droughts in the
Southeast have increased by 12 percent during spring months and by 14
percent during summer months (Jones et al. 2015, p. 126). Declines of
65-83 percent in mussel density were observed after severe droughts in
the upper reaches of the Sipsey River, and decreases in dissolved
oxygen and increases in temperature were cited as causes for the
decline (Haag and Warren 2008, pp. 1165-1178). As mentioned, Obovaria
cf. unicolor is sensitive to drops and fluctuations in dissolved oxygen
and to elevated temperatures (van Ee et al. 2022, pp.1-14) since it is
naturally adapted to larger riverine systems. The effects of higher
temperatures and reduced flows are expected to affect subpopulations of
the species in upstream reaches first, reducing overall population
resiliency (Haag and Warren 2008, pp.1165-1178).
Sea Level Rise
Sea level rise (SLR) impacts future resilience of Obovaria cf.
unicolor by influencing the area occupied and habitat available through
increased salinity. To estimate loss/degradation of
[[Page 73341]]
habitat due to inundation from SLR, we used the National Oceanic and
Atmospheric Administration's (NOAA's) shapefiles available at their
online sea level rise viewer (NOAA 2020, unpaginated). Projected SLR
scenarios from NOAA provide a range of inundation levels from low to
extreme. We chose NOAA's intermediate-high and extreme scenarios, which
correspond to the representative concentration pathway (RCP)4.5 and
RCP8.5 emission scenarios, to encompass the breadth of possible
scenarios (IPCC 2013, p. 20). Local scenarios are available at a
location near Mobile Bay in Alabama, and they provide estimates of SLR
affecting the range of Obovaria cf. unicolor at decadal time steps out
to the year 2100. We found the average+ SLR estimate for the
intermediate and extreme NOAA scenarios from this station and used the
estimate (rounded to the nearest foot, because shapefiles are only
available at 1-foot increments) to project estimated habitat loss at
years 2040 and 2070. Where SLR estimates overlap with known occupied
portions of the river system, we assume that area is no longer
occupiable by Obovaria cf. unicolor.
As expected, projections of SLR only impacted Obovaria cf. unicolor
in occupied habitat of coastal drainages. Obovaria cf. unicolor has
projected SLR impacts in the three Pontchartrain drainages: the Amite,
the Tickfaw, and the Tangipahoa. The Amite population is already
considered extirpated, but we expect SLR to result in contraction of
the Tickfaw and Tangipahoa populations in the future, which would
reduce each of these population's resiliency from high resiliency to
moderate resiliency, and thus reduce their contribution to species
representation and redundancy in the future. In the Tickfaw, we project
a loss of 8.4 to 17.9 river miles, which corresponds to a 24 to 51
percent range reduction, and in the Tangipahoa, we project a loss of
4.5 to 7.3 river miles, which corresponds to a 7.5 to 12.1 percent
range reduction.
Future Viability Summary
In summary, we expect decreased resiliency, redundancy, and
representation in the future for Obovaria cf. unicolor. The magnitude
of reduction in resiliency, redundancy, and representation for this
species will depend on the climate change scenario realized and the
outcomes of future water engineering projects, which are the two main
influences that are expected to exacerbate the negative impacts that
populations are experiencing due to habitat fragmentation and range
constriction.
Obovaria cf. unicolor will be vulnerable to future impacts
throughout its remaining range. The effects of climate change from sea
level rise will reduce the already limited ranges of the Tangipahoa and
Tickfaw populations. Obovaria cf. unicolor will also experience
negative impacts from the increased temperatures, increased occurrences
of drought, and reduced dissolved oxygen across the species' range.
Meanwhile, the effects of future channel modification projects have the
potential to reduce resiliency in the Upper Pearl, Lower Pearl, and
Pascagoula populations. Only one population will have high resiliency
(Pascagoula), two will have moderate resiliency (Tangipahoa and
Tickfaw), and one will have low resiliency (Pearl); the Amite
population would remain extirpated. Additionally, due to this expected
decrease in future population resiliency and to the expected continued
reduction in population ranges, species redundancy and representation
are also expected to decrease in the future. Representation will move
from currently moderate to low. This will result in decreased adaptive
capacity. Redundancy will move from currently moderate to low.
Determination of Status
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations (50 CFR part 424) set forth the procedures for determining
whether a species meets the definition of an endangered species or a
threatened species. The Act defines an ``endangered species'' as a
species in danger of extinction throughout all or a significant portion
of its range and a ``threatened species'' as a species likely to become
an endangered species within the foreseeable future throughout all or a
significant portion of its range. The Act requires that we determine
whether a species meets the definition of an endangered species or a
threatened species because of any of the following factors: (A) The
present or threatened destruction, modification, or curtailment of its
habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; or (E) other natural or
manmade factors affecting its continued existence.
i. Alabama Hickorynut
Alabama Hickorynut--Status Throughout All of Its Range
After evaluating threats to the species and assessing the
cumulative effect of the threats under the Act's section 4(a)(1)
factors, we determined the primary threats affecting the biological
status of Alabama hickorynut include the following: sedimentation,
altered flow regimes, point and nonpoint source pollution, and direct
and indirect impacts of development and anthropogenic disturbances
(Factor A), and impacts of climate change, including sea level rise
(Factor E). We delineated 16 Alabama hickorynut subpopulations in three
populations across the species' historical range; 13 subpopulations in
one population are extant. In our current condition analysis, we
assessed habitat condition and population demographics to determine the
species' current resiliency. Populations with occurrences since 2000
were considered current. Two Alabama hickorynut populations in the
Mobile River Basin have been extirpated (Alabama and Cahaba) and are
not expected to naturally re-establish. The one extant Alabama
hickorynut population exhibits low current resiliency (Tombigbee).
Based on differences in ecological settings and connectivity at a
larger scale, we delineated two representative units for the Alabama
hickorynut in the Mobile River Basin: the extirpated Eastern Mobile
River Basin (Alabama and Cahaba Rivers) and the Western Mobile River
Basin (Tombigbee River). The extant Western Mobile River Basin
representative unit is highly fragmented with no connectivity between
subpopulations following the completion of the TTW in 1984. This
project led to the extirpation of the species from the Tombigbee
mainstem due to dredging, channelization, and installation of
impoundments, which eliminated gene flow between the tributaries of the
Tombigbee River. We determined that the Alabama hickorynut's overall
ability to adapt to changing environmental conditions (representation
or adaptive capacity) is low.
With one population in low resiliency, the Alabama hickorynut has
low redundancy. However, some redundancy is possible within the
population, with 7 of the 13 subpopulations distributed such that it
would be unlikely for one catastrophic event to extirpate all the
subpopulations at once. However, six of seven subpopulations have low
abundance, making them more vulnerable to
[[Page 73342]]
potential extirpation by catastrophic events.
Our analysis of the species' current condition, as well as the
conservation efforts discussed above, show that the Alabama hickorynut
is currently in danger of extinction throughout all of its range due to
the severity and immediacy of threats currently impacting its
populations. The threats are occurring across the entire range of this
species, and the species currently exhibits low resiliency, redundancy,
and representation. Thus, after assessing the best scientific and
commercial data available, we determined that the species meets the
definition of an endangered species throughout all of its range.
Alabama Hickorynut--Status Throughout a Significant Portion of Its
Range
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
within the foreseeable future throughout all or a significant portion
of its range. We have determined that the Alabama hickorynut is in
danger of extinction throughout all of its range and accordingly did
not undertake an analysis of any significant portion of its range.
Because the Alabama hickorynut warrants listing as endangered
throughout all of its range, our determination does not conflict with
the decision in Center for Biological Diversity v. Everson, 435 F.
Supp. 3d. 69 (D.D.C. 2020) (Everson), because that decision related to
significant portion of the range analyses for species that warrant
listing as threatened, not endangered, throughout all of their range.
Alabama Hickorynut--Determination of Status
Our review of the best available scientific and commercial
information indicates that the Alabama hickorynut meets the Act's
definition of an endangered species. Therefore, we propose to list the
Alabama hickorynut as an endangered species in accordance with sections
3(6) and 4(a)(1) of the Act.
ii. Obovaria cf. Unicolor
Obovaria cf. Unicolor--Status Throughout All of Its Range
After evaluating threats to the species and assessing the
cumulative effect of the threats under the Act's section 4(a)(1)
factors, we determined that the primary threats affecting the
biological status of Obovaria cf. unicolor include: sedimentation,
altered flow regimes, point and nonpoint source pollution, and direct
and indirect impacts of development and anthropogenic disturbances
(Factor A), and impacts of climate change, including sea level rise
(Factor E).
Historically, Obovaria cf. unicolor was known from 1,454 river
miles in Mississippi and Louisiana. The species currently occupies 788
river miles, or 54 percent of its historical range. We delineated 13
subpopulations in 6 populations across the species' historical range.
The Amite population of Obovaria cf. unicolor is extirpated. Of five
extant populations, two exhibit low current resiliency (Upper Pearl,
Lower Pearl), and three exhibit high current resiliency (Pascagoula,
Tangipahoa, Tickfaw).
Although Obovaria cf. unicolor is extant in four of five
representative units: Pascagoula, Pearl, Tangipahoa, and Tickfaw,
connectivity within and between the representative units is very low
due to unsuitable habitat conditions. The species declines in abundance
and distribution indicate it may not be able to tolerate major
environmental changes; therefore, we determined Obovaria cf. unicolor
also has minimal ability to adapt to changing environmental conditions
(adaptive capacity). However, three Obovaria cf. unicolor populations
currently with high resiliency are distributed across the species
range, so the species currently has moderate redundancy. Given that
Obovaria cf. unicolor is still present in four representative units,
three of the populations are high resiliency, and these populations are
distributed across the range, Obovaria cf. unicolor is not currently in
danger of extinction.
In the future, continued modification to channels and resource
extraction are expected to occur within the range of Obovaria cf.
unicolor. Additionally, one to 5 feet of sea level rise (depending on
the sea level rise scenario) would affect the Tickfaw and Tangipahoa
populations, causing a range contraction for the species. Species
resilience will decrease, with only one population with high resiliency
(Pascagoula), two with moderate resiliency (Tangipahoa and Tickfaw),
and one with low resiliency (Pearl); the Amite population will remain
extirpated. Representation will move from currently moderate to low.
This will result in decreased adaptive capacity. Redundancy will move
from currently moderate to low.
Thus, after assessing the best scientific and commercial data
available, we determine that Obovaria cf. unicolor is not currently in
danger of extinction but is likely to become in danger of extinction
within the foreseeable future throughout all of its range.
Obovaria cf. Unicolor--Status Throughout a Significant Portion of Its
Range
Under the Act and our implementing regulations, a species may
warrant listing if it is in danger of extinction or likely to become so
within the foreseeable future throughout all or a significant portion
of its range. The court in Everson vacated the aspect of the Final
Policy on Interpretation of the Phrase ``Significant Portion of Its
Range'' in the Endangered Species Act's Definitions of ``Endangered
Species'' and ``Threatened Species'' (hereafter ``Final Policy''; 79 FR
37578, July 1, 2014) that provided if the Services determine that a
species is threatened throughout all of its range, the Services will
not analyze whether the species is endangered in a significant portion
of its range.
Therefore, we proceed to evaluating whether the species is
endangered in a significant portion of its range--that is, whether
there is any portion of the species' range for which both (1) the
portion is significant; and (2) the species is in danger of extinction
in that portion. Depending on the case, it might be more efficient for
us to address the ``significance'' question or the ``status'' question
first. We can choose to address either question first. Regardless of
which question we address first, if we reach a negative answer with
respect to the first question that we address, we do not need to
evaluate the other question for that portion of the species' range.
Following the court's holding in Everson, we now consider whether
the species is in danger of extinction in a significant portion of its
range. In undertaking this analysis for Obovaria cf. unicolor, we
choose to address the status question first.
We evaluated the range of the Obovaria cf. unicolor to determine if
the species is in danger of extinction in any portion of its range. The
range of the species can theoretically be divided into portions in an
infinite number of ways. We focused our analysis on portions of the
species' range that may meet the definition of an endangered species.
For Obovaria cf. unicolor, we considered whether the threats or their
effects on the species are greater in any biologically meaningful
portion of the species' range than in other portions such that the
species is in danger of extinction in that portion.
We examined the following threats: sedimentation, altered flow
regimes, point and nonpoint source pollution, impacts of climate
change, including sea
[[Page 73343]]
level rise, and direct and indirect impacts of development and
anthropogenic disturbances, including cumulative effects.
The Pearl River unit (upper and lower populations) is the only unit
that could conceivably be in danger of extinction now. The Amite
population is extirpated, and lost historical range cannot be a
significant portion of a species' range under the Final Policy. The
Pascagoula, Tangipahoa, and Tickfaw populations all currently exhibit
high resiliency. On the other hand, the Pearl River unit has highly
fragmented habitat and low resiliency, representation, and redundancy.
Additionally, within this unit, Obovaria cf. unicolor has lost a large
portion of its range, and the Pearl River (above and below the
reservoir) has experienced a high degree of channel modification and
changes in flow regime, resulting in degraded and unsuitable habitat
conditions for Obovaria cf. unicolor Therefore, the populations in this
unit may have a different status than the rest of the range (i.e., this
portion may be in danger of extinction).
As a result, we move to the significance question. We considered
whether the portion may (1) occur in a unique habitat or ecoregion for
the species; (2) contain high-quality or high-value habitat relative to
the remaining portions of the range; (3) contain habitat that is
essential to a specific life-history function for the species and that
is not found in the other portions (for example, the principal breeding
ground for the species); or (4) contain a large geographic portion of
the suitable habitat relative to the remaining portions of the range
for the species. The Pearl River unit is not a significant portion of
the range because it does not represent a large geographic portion of
Obovaria cf. unicolor's range (i.e., it constitutes approximately 18
percent of the occupied range), it is not high-quality habitat relative
to the remaining portion of the range (the highest quality habitat is
in the Pascagoula unit), and it does not provide unique or important
resources to a particular life stage of Obovaria cf. unicolor.
Therefore, no portion of the species' range provides a basis for
determining that the species is in danger of extinction in a
significant portion of its range, and we determine that the species is
likely to become in danger of extinction within the foreseeable future
throughout all of its range. This does not conflict with the courts'
holdings in Desert Survivors v. Department of the Interior, 321 F.
Supp. 3d 1011, 1070-74 (N.D. Cal. 2018), and Center for Biological
Diversity v. Jewell, 248 F. Supp. 3d, 946, 959 (D. Ariz. 2017),
because, in reaching this conclusion, we did not apply the aspects of
the Final Policy, including the definition of ``significant'' that
those court decisions held to be invalid.
Obovaria cf. Unicolor--Determination of Status
Our review of the best available scientific and commercial
information indicates that Obovaria cf. unicolor meets the Act's
definition of a threatened species. Therefore, we propose to list
Obovaria cf. unicolor as a threatened species in accordance with
sections 3(20) and 4(a)(1) of the Act.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened species under the Act include recognition as a listed
species, planning and implementation of recovery actions, requirements
for Federal protection, and prohibitions against certain practices.
Recognition through listing results in public awareness, and
conservation by Federal, State, Tribal, and local agencies, foreign
governments, private organizations, and individuals. The Act encourages
cooperation with the States and other countries and calls for recovery
actions to be carried out for listed species. The protection required
by Federal agencies, including the Service, and the prohibitions
against certain activities are discussed, in part, below.
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Section 4(f) of the Act calls for the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The goal of this process is to restore listed
species to a point where they are secure, self-sustaining, and
functioning components of their ecosystems.
The recovery planning process begins with development of a recovery
outline made available to the public soon after a final listing
determination. The recovery outline guides the immediate implementation
of urgent recovery actions while a recovery plan is being developed.
Recovery teams (composed of species experts, Federal and State
agencies, nongovernmental organizations, and stakeholders) may be
established to develop and implement recovery plans. The recovery
planning process involves the identification of actions that are
necessary to halt and reverse the species' decline by addressing the
threats to its survival and recovery. The recovery plan identifies
recovery criteria for review of when a species may be ready for
reclassification from endangered to threatened (``downlisting'') or
removal from protected status (``delisting''), and methods for
monitoring recovery progress. Recovery plans also establish a framework
for agencies to coordinate their recovery efforts and provide estimates
of the cost of implementing recovery tasks. Revisions of the plan may
be done to address continuing or new threats to the species, as new
substantive information becomes available. The recovery outline, draft
recovery plan, final recovery plan, and any revisions will be available
on our website as they are completed (<a href="https://www.fws.gov/program/endangered-species">https://www.fws.gov/program/endangered-species</a>), or from our Alabama Ecological Services Field
Office (see FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribes, nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research, captive
propagation and reintroduction, and outreach and education. The
recovery of many listed species cannot be accomplished solely on
Federal lands because their ranges may occur primarily or solely on
non-Federal lands. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
If these species are listed, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost-share grants for non-Federal landowners, the
academic community, and nongovernmental organizations. In addition,
pursuant to section 6 of the Act, the State of Alabama would be
eligible for Federal funds to implement management actions that promote
the protection or recovery of Alabama hickorynut or Obovaria cf.
unicolor. Information on our grant programs that are available to aid
species recovery can be found at: <a href="https://www.fws.gov/service/financial-assistance">https://www.fws.gov/service/financial-assistance</a>.
Although the Alabama hickorynut and Obovaria cf. unicolor are only
proposed for listing under the Act at this time, please let us know if
you are interested in participating in recovery efforts for this
species. Additionally, we invite you to submit any new
[[Page 73344]]
information on these species whenever it becomes available and any
information you may have for recovery planning purposes (see FOR
FURTHER INFORMATION CONTACT).
Section 7 of the Act is titled, ``Interagency Cooperation,'' and it
mandates all Federal action agencies to use their existing authorities
to further the conservation purposes of the Act and to ensure that
their actions are not likely to jeopardize the continued existence of
listed species or adversely modify critical habitat. Regulations
implementing section 7 are codified at 50 CFR part 402.
Section 7(a)(2) states that each Federal action agency shall, in
consultation with the Secretary, ensure that any action they authorize,
fund, or carry out is not likely to jeopardize the continued existence
of a listed species or result in the destruction or adverse
modification of designated critical habitat. Each Federal agency shall
review its action at the earliest possible time to determine whether it
may affect listed species or critical habitat. If a determination is
made that the action may affect listed species or critical habitat,
formal consultation is required (50 CFR 402.14(a)), unless the Service
concurs in writing that the action is not likely to adversely affect
listed species or critical habitat. At the end of a formal
consultation, the Service issues a biological opinion, containing its
determination of whether the Federal action is likely to result in
jeopardy or adverse modification.
In contrast, section 7(a)(4) of the Act requires Federal agencies
to confer with the Service on any action which is likely to jeopardize
the continued existence of any species proposed to be listed under the
Act or result in the destruction or adverse modification of critical
habitat proposed to be designated for such species. Although the
conference procedures are required only when an action is likely to
result in jeopardy or adverse modification, action agencies may
voluntarily confer with the Service on actions that may affect species
proposed for listing or critical habitat proposed to be designated. In
the event that the subject species is listed or the relevant critical
habitat is designated, a conference opinion may be adopted as a
biological opinion and serve as compliance with section 7(a)(2) of the
Act.
Examples of discretionary actions for Alabama hickorynut and
Obovaria cf. unicolor that may be subject to conference and
consultation under section 7 are land management or other landscape-
altering activities on Federal lands administered by the USACE, U.S.
Department of Agriculture (including the Natural Resources Conservation
Service, Farm Services Agency, and U.S. Forest Service), U.S.
Department of Energy, U.S. Department of Transportation, U.S.
Environmental Protection Agency (EPA), and U.S. Fish and Wildlife
Service, as well as actions on State, Tribal, local, or private lands
that require a Federal permit (such as a permit from the USACE under
section 404 of the Clean Water Act (33 U.S.C. 1251 et seq.) or a permit
from the Service under section 10 of the Act) or that involve some
other Federal action (such as funding from the Federal Highway
Administration, Federal Aviation Administration, or the Federal
Emergency Management Agency). Federal actions not affecting listed
species or critical habitat--and actions on State, Tribal, local, or
private lands that are not federally funded, authorized, or carried out
by a Federal agency--do not require section 7 consultation. Federal
agencies should coordinate with the local Service Field Office (see FOR
FURTHER INFORMATION CONTACT, above) with any specific questions on
section 7 consultation and conference requirements.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to endangered wildlife.
The prohibitions of section 9(a)(1) of the Act, and the Service's
implementing regulations codified at 50 CFR 17.21, make it illegal for
any person subject to the jurisdiction of the United States to commit,
to attempt to commit, to solicit another to commit, or to cause to be
committed any of the following acts with regard to any endangered
wildlife: (1) import into, or export from, the United States; (2) take
(which includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect, or to attempt to engage in any such conduct)
within the United States, within the territorial sea of the United
States, or on the high seas; (3) possess, sell, deliver, carry,
transport, or ship, by any means whatsoever, any such wildlife that has
been taken illegally; (4) deliver, receive, carry, transport, or ship
in interstate or foreign commerce, by any means whatsoever and in the
course of commercial activity; or (5) sell or offer for sale in
interstate or foreign commerce. Certain exceptions to these
prohibitions apply to employees or agents of the Service, the National
Marine Fisheries Service, other Federal land management agencies, and
State conservation agencies.
We may issue permits to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. Regulations
governing permits for endangered wildlife are codified at 50 CFR 17.22,
and general Service permitting regulations are codified at 50 CFR part
13. With regard to endangered wildlife, a permit may be issued: for
scientific purposes, for enhancing the propagation or survival of the
species, or for take incidental to otherwise lawful activities. The
statute also contains certain exemptions from the prohibitions, which
are found in sections 9 and 10 of the Act.
II. Protective Regulations Under Section 4(d) of the Act for Obovaria
cf. Unicolor
Background
Section 4(d) of the Act contains two sentences. The first sentence
states that the Secretary shall issue such regulations as she deems
necessary and advisable to provide for the conservation of species
listed as threatened species. Conservation is defined in the Act to
mean the use of all methods and procedures which are necessary to bring
any endangered species or threatened species to the point at which the
measures provided pursuant to the Act are no longer necessary.
Additionally, the second sentence of section 4(d) of the Act states
that the Secretary may by regulation prohibit with respect to any
threatened species any act prohibited under section 9(a)(1), in the
case of fish or wildlife, or section 9(a)(2), in the case of plants.
With these two sentences in section 4(d), Congress delegated broad
authority to the Secretary to determine what protections would be
necessary and advisable to provide for the conservation of threatened
species, and even broader authority to put in place any of the section
9 prohibitions for a given species.
The courts have recognized the extent of the Secretary's discretion
under this standard to develop rules that are appropriate for the
conservation of a species. For example, courts have upheld, as a valid
exercise of agency authority, rules developed under section 4(d) that
included limited prohibitions against takings (see Alsea Valley
Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington
Environmental Council v. National Marine Fisheries Service, 2002 WL
511479 (W.D. Wash. 2002)). Courts have also upheld 4(d) rules that do
not address all of the threats a species faces (see State of Louisiana
v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted in the legislative
history when the Act was initially enacted, ``once an animal is on the
threatened list, the Secretary has an
[[Page 73345]]
almost infinite number of options available to [her] with regard to the
permitted activities for those species. [She] may, for example, permit
taking, but not importation of such species, or [she] may choose to
forbid both taking and importation but allow the transportation of such
species'' (H.R. Rep. No. 412, 93rd Cong., 1st Sess. 1973).
The provisions of this species' proposed protective regulations
under section 4(d) of the Act are one of many tools that we would use
to promote the conservation of Obovaria cf. unicolor. The proposed
protective regulations would apply only if and when we make final the
listing of Obovaria cf. unicolor as a threatened species. Nothing in
4(d) rules change in any way the recovery planning provisions of
section 4(f) of the Act, the consultation requirements under section 7
of the Act, or the ability of the Service to enter into partnerships
for the management and protection of Obovaria cf. unicolor. As
mentioned previously in Available Conservation Measures, section
7(a)(2) of the Act requires Federal agencies, including the Service, to
ensure that any action they authorize, fund, or carry out is not likely
to jeopardize the continued existence of any endangered species or
threatened species or result in the destruction or adverse modification
of designated critical habitat of such species. In addition, even
before the listing of any species or the designation of its critical
habitat is finalized, section 7(a)(4) of the Act requires Federal
agencies to confer with the Service on any agency action which is
likely to jeopardize the continued existence of any species proposed to
be listed under the Act or result in the destruction or adverse
modification of critical habitat proposed to be designated for such
species. These requirements are the same for a threatened species
regardless of what is included in its 4(d) rule.
Section 7 consultation is required for Federal actions that ``may
affect'' a listed species regardless of whether take caused by the
activity is prohibited or excepted by a 4(d) rule (under general
application of the ``blanket rule'' option (for more information, see
89 FR 23919, April 5, 2024) or a species-specific 4(d) rule). A 4(d)
rule does not change the process and criteria for informal or formal
consultations and does not alter the analytical process used for
biological opinions or concurrence letters. For example, as with an
endangered species, if a Federal agency determines that an action is
``not likely to adversely affect'' a threatened species, this will
require the Service's written concurrence (50 CFR 402.13(c)).
Similarly, if a Federal agency determinates that an action is ``likely
to adversely affect'' a threatened species, the action will require
formal consultation with the Service and the formulation of a
biological opinion (50 CFR 402.14(a)). Because consultation obligations
and processes are unaffected by 4(d) rules, we may consider developing
tools to streamline future intra-Service and interagency consultations
for actions that result in forms of take that are not prohibited by the
4(d) rule (but that still require consultation). These tools may
include consultation guidance, Information for Planning and
Consultation effects determination keys, template language for
biological opinions, or programmatic consultations.
Provisions of the Proposed 4(d) Rule
Exercising the Secretary's authority under section 4(d) of the Act,
we have developed a proposed rule that is designed to address Obovaria
cf. unicolor's conservation needs. As discussed previously under
Summary of Biological Status and Threats, we have concluded that
Obovaria cf. unicolor is likely to become in danger of extinction
within the foreseeable future primarily due to sedimentation, altered
flow regimes, point and nonpoint source pollution, impacts of climate
change, including sea level rise, and direct and indirect impacts of
development and anthropogenic disturbances. There are other activities
that could affect the species and its habitat if they occur in areas
occupied by the species, such as impacts to water quality and quantity.
Section 4(d) requires the Secretary to issue such regulations as
she deems necessary and advisable to provide for the conservation of
each threatened species and authorizes the Secretary to include among
those protective regulations any of the prohibitions that section
9(a)(1) of the Act prescribes for endangered species. We are not
required to make a ``necessary and advisable'' determination when we
apply or do not apply specific section 9 prohibitions to a threatened
species (In re: Polar Bear Endangered Species Act Listing and 4(d) Rule
Litigation, 818 F. Supp. 2d 214, 228 (D.D.C. 2011) (citing Sweet Home
Chapter of Cmtys. for a Great Or. v. Babbitt, 1 F.3d 1, 8 (D.C. Cir.
1993), rev'd on other grounds, 515 U.S. 687 (1995))). Nevertheless,
even though we are not required to make such a determination, we have
chosen to be as transparent as possible and explain below why we find
that, if finalized, the protections, prohibitions, and exceptions in
this proposed rule as a whole would satisfy the requirement in section
4(d) of the Act to issue regulations deemed necessary and advisable to
provide for the conservation of the Obovaria cf. unicolor.
The protective regulations we are proposing for Obovaria cf.
unicolor incorporate prohibitions from section 9(a)(1) of the Act to
address the threats to the species. The prohibitions of section 9(a)(1)
of the Act, and implementing regulations codified at 50 CFR 17.21, make
it illegal for any person subject to the jurisdiction of the United
States to commit, to attempt to commit, to solicit another to commit or
to cause to be committed any of the following acts with regard to any
endangered wildlife: (1) import into, or export from, the United
States; (2) take (which includes harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect) within the United States,
within the territorial sea of the United States, or on the high seas;
(3) possess, sell, deliver, carry, transport, or ship, by any means
whatsoever, any such wildlife that has been taken illegally; (4)
deliver, receive, carry, transport, or ship in interstate or foreign
commerce, by any means whatsoever and in the course of commercial
activity; or (5) sell or offer for sale in interstate or foreign
commerce.
In particular, this proposed 4(d) rule would provide for the
conservation of the Obovaria cf. unicolor by prohibiting the following
activities, unless they fall within specific exceptions or are
otherwise authorized or permitted: importing or exporting; take;
possession and other acts with unlawfully taken specimens; delivering,
receiving, carrying, transporting, or shipping in interstate or foreign
commerce in the course of commercial activity; or selling or offering
for sale in interstate or foreign commerce.
Under the Act, ``take'' means to harass, harm, pursue, hunt, shoot,
wound, kill, trap, capture, or collect, or to attempt to engage in any
such conduct. Some of these provisions have been further defined in
regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by
direct and indirect impacts, intentionally or incidentally. Regulating
take would help preserve the species' remaining populations and
decrease synergistic, negative effects from other ongoing or future
threats. Therefore, we propose to prohibit take of Obovaria cf.
unicolor, except for take resulting from those actions and activities
specifically excepted by the 4(d) rule.
Exceptions to the prohibition on take would include all of the
general exceptions to the prohibition on take of
[[Page 73346]]
endangered wildlife, as set forth in 50 CFR 17.21, and additional
exceptions, as described below.
Despite the prohibitions regarding threatened species, we may under
certain circumstances issue permits to carry out one or more otherwise-
prohibited activities, including those described above. The regulations
that govern permits for threatened wildlife state that the Director may
issue a permit authorizing any activity otherwise prohibited with
regard to threatened species. These include permits issued for the
following purposes: for scientific purposes, to enhance propagation or
survival, for economic hardship, for zoological exhibition, for
educational purposes, for incidental taking, or for special purposes
consistent with the purposes of the Act (see 50 CFR 17.32). The statute
also contains certain exemptions from the prohibitions, which are found
in sections 9 and 10 of the Act.
In addition, to further the conservation of the species, any
employee or agent of the Service, any other Federal land management
agency, the National Marine Fisheries Service, a State conservation
agency, or a federally recognized Tribe, who is designated by their
agency or Tribe for such purposes, may, when acting in the course of
their official duties, take threatened wildlife without a permit if
such action is necessary to: (i) Aid a sick, injured, or orphaned
specimen; or (ii) dispose of a dead specimen; or (iii) salvage a dead
specimen that may be useful for scientific study; or (iv) remove
specimens that constitute a demonstrable but nonimmediate threat to
human safety, provided that the taking is done in a humane manner; the
taking may involve killing or injuring only if it has not been
reasonably possible to eliminate such threat by live capturing and
releasing the specimen unharmed, in an appropriate area.
We recognize the special and unique relationship with our State
natural resource agency partners in contributing to conservation of
listed species. State agencies often possess scientific data and
valuable expertise on the status and distribution of endangered,
threatened, and candidate species of wildlife and plants. State
agencies, because of their authorities and their close working
relationships with local governments and landowners, are in a unique
position to assist us in implementing all aspects of the Act. In this
regard, section 6 of the Act provides that we must cooperate to the
maximum extent practicable with the States in carrying out programs
authorized by the Act. Therefore, any qualified employee or agent of a
State conservation agency that is a party to a cooperative agreement
with us in accordance with section 6(c) of the Act, who is designated
by his or her agency for such purposes, would be able to conduct
activities designed to conserve Obovaria cf. unicolor that may result
in otherwise prohibited take without additional authorization.
The proposed 4(d) rule would also provide for the conservation of
the species by allowing exceptions that incentivize conservation
actions or that, while they may have some minimal level of take of
Obovaria cf. unicolor, are not expected to rise to the level that would
have a negative impact (i.e., would have only de minimis impacts) on
the species' conservation. The proposed exceptions to the prohibitions
include (1) channel and bank restoration projects, (2) silviculture
practices and forest management activities that implement State-
approved best management practices (BMPs), and (3) transportation
projects that avoid instream disturbance in waters occupied by Obovaria
cf. unicolor. These proposed exceptions to the prohibitions are
described further below and are expected to have negligible impacts to
Obovaria cf. unicolor and its habitat.
The first exception is for incidental take resulting from channel
and bank restoration projects for creation of natural, physically
stable, ecologically functioning streams, taking into consideration
connectivity with floodplain and groundwater aquifers. This exception
includes a requirement that stream bank restoration projects require
planting appropriate native vegetation, including woody species
appropriate for the region and habitat. Actions related to these
restoration projects that would negatively affect Obovaria cf. unicolor
include individual mussels being removed, crushed, and/or killed by
heavy equipment operations and rip-rap placement; removal, destruction,
and/or replacement of habitat; increased turbidity from streambed
disturbance; and alterations to flow and turbidity from permanent
(weirs) or temporary (causeways) structures needed for construction.
This provision of the proposed 4(d) rule for channel and bank
restoration would promote conservation of Obovaria cf. unicolor by
excepting incidental take resulting from activities that would improve
channel conditions and restore degraded, physically unstable streams or
stream segments. We anticipate these activities will advance ecological
conditions within a watershed to a more natural state that would
benefit Obovaria cf. unicolor, providing for its conservation.
The second exception is for incidental take resulting from
silviculture practices and forest management activities that use State-
approved BMPs to protect water and sediment quality and stream and
riparian habitat. Silviculture and forest management activities that
use State-approved BMPs to protect water and sediment quality and
stream and riparian habitat would provide for the conservation of
Obovaria cf. unicolor. Best management practices would have to be
designed to reduce sedimentation, erosion, and bank destruction,
thereby protecting instream habitat for the species. We recognize that
silvicultural operations are widely implemented in accordance with
State-approved BMPs (as reviewed by Cristan et al. 2018, entire), and
the adherence to these BMPs broadly protects water quality,
particularly related to sedimentation (as reviewed by Cristan et al.
2016, entire; Warrington et al. 2017, entire; Schilling et al. 2021,
entire). This provision of the 4(d) rule would promote conservation of
Obovaria cf. unicolor by excepting from the prohibition on incidental
take those silviculture and forest management activities that use
State-approved BMPs because this exception would allow these activities
to continue while protecting Obovaria cf. unicolor's habitat.
The third exception is for incidental take resulting from
transportation projects that avoid or do not include activities that
disturb instream habitat. Bridge designs that include spanning the
stream and avoiding stream bank disturbance reduce sedimentation and
erosion, thereby protecting instream habitat for Obovaria cf. unicolor.
This provision of the 4(d) rule would promote conservation of Obovaria
cf. unicolor by encouraging project designs that preserve and
potentially improve stream habitat.
III. Critical Habitat
Background
Critical habitat is defined in section 3 of the Act as:
(1) The specific areas within the geographical area occupied by the
species, at the time it is listed in accordance with the Act, on which
are found those physical or biological features
(a) Essential to the conservation of the species, and
(b) Which may require special management considerations or
protection; and
(2) Specific areas outside the geographical area occupied by the
species at the time it is listed, upon a determination that such areas
are
[[Page 73347]]
essential for the conservation of the species.
Our regulations at 50 CFR 424.02 define the geographical area
occupied by the species as an area that may generally be delineated
around species' occurrences, as determined by the Secretary (i.e.,
range). Such areas may include those areas used throughout all or part
of the species' life cycle, even if not used on a regular basis (e.g.,
migratory corridors, seasonal habitats, and habitats used periodically,
but not solely by vagrant individuals).
Conservation, as defined under section 3 of the Act, means to use
and the use of all methods and procedures that are necessary to bring
an endangered or threatened species to the point at which the measures
provided pursuant to the Act are no longer necessary. Such methods and
procedures include, but are not limited to, all activities associated
with scientific resources management such as research, census, law
enforcement, habitat acquisition and maintenance, propagation, live
trapping, and transplantation, and, in the extraordinary case where
population pressures within a given ecosystem cannot be otherwise
relieved, may include regulated taking.
Critical habitat receives protection under section 7 of the Act
through the requirement that Federal agencies ensure, in consultation
with the Service, that any action they authorize, fund, or carry out is
not likely to result in the destruction or adverse modification of
critical habitat. The designation of critical habitat does not affect
land ownership or establish a refuge, wilderness, reserve, preserve, or
other conservation area. Such designation also does not allow the
government or public to access private lands. Such designation does not
require implementation of restoration, recovery, or enhancement
measures by non-Federal landowners. Rather, designation requires that,
where a landowner requests Federal agency funding or authorization for
an action that may affect an area designated as critical habitat, the
Federal agency consult with the Service under section 7(a)(2) of the
Act. If the action may affect the listed species itself (such as for
occupied critical habitat), the Federal agency would have already been
required to consult with the Service even absent the designation
because of the requirement to ensure that the action is not likely to
jeopardize the continued existence of the species. Even if the Service
were to conclude after consultation that the proposed activity is
likely to 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).
Under the second prong of the Act's definition of critical habitat,
we can designate critical habitat in areas outside the geographical
area occupied by the species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific data available. Further, our Policy on
Information Standards Under the Endangered Species Act (published in
the Federal Register on July 1, 1994 (59 FR 34271)), the Information
Quality Act (section 515 of the Treasury and General Government
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)),
and our associated Information Quality Guidelines provide criteria,
establish procedures, and provide guidance to ensure that our decisions
are based on the best scientific data available. They require our
biologists, to the extent consistent with the Act and with the use of
the best scientific data available, to use primary and original sources
of information as the basis for recommendations to designate critical
habitat.
When we are determining which areas should be designated as
critical habitat, our primary source of information is generally the
information from the SSA report and information developed during the
listing process for the species. Additional information sources may
include any generalized conservation, criteria, or outline that may
have been developed for the species; the recovery plan for the species;
articles in peer-reviewed journals; conservation plans developed by
States and counties; scientific status surveys and studies; biological
assessments; other unpublished materials; or experts' opinions or
personal knowledge.
Habitat is dynamic, and species may move from one area to another
over time. We recognize that critical habitat designated at a
particular point in time may not include all of the habitat areas that
we may later determine are necessary for the recovery of the species.
For these reasons, a critical habitat designation does not signal that
habitat outside the designated area is unimportant or may not be needed
for recovery of the species. Areas that are important to the
conservation of the species, both inside and outside the critical
habitat designation, will continue to be subject to: (1) Conservation
actions implemented under section 7(a)(1) of the Act; (2) regulatory
protections afforded by the requirement in section 7(a)(2) of the Act
for Federal agencies to ensure their actions are not likely to
jeopardize the continued existence of any endangered or threatened
species; and (3) the prohibitions found in section 9 of the Act for
Alabama hickorynut and in the 4(d) rule for Obovaria cf. unicolor.
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 the 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 those planning efforts calls for a
different outcome.
Critical Habitat Determinability
We determine that designating critical habitat for the Alabama
hickorynut and Obovaria cf. unicolor is prudent. Our regulations at 50
CFR 424.12(a)(2) state that designation of critical habitat is not
determinable when one or both of the following situations exist:
(i) Data sufficient to perform required analyses are lacking, or
(ii) The biological needs of the species are not sufficiently well
known to identify any area that meets the definition of ``critical
habitat.''
We reviewed the available informationpertaining to the biological
needs of the species and habitat characteristics where these species
are
[[Page 73348]]
located. The species' needs of both the Alabama hickorynut and Obovaria
cf. unicolor are sufficiently well known, but a careful assessment of
the economic impacts that may occur due to a critical habitat
designation is ongoing. Until these efforts are complete, information
sufficient to perform a required analysis of the impacts of the
designation is lacking; therefore, we find designation of critical
habitat for both the Alabama hickorynut and Obovaria cf. unicolor is
prudent but not determinable at this time. We plan to publish a
proposed rule to designate critical habitat for both the Alabama
hickorynut and Obovaria cf. unicolor concurrently with the availability
of an economic analysis of the proposed designation.
Required Determinations
Clarity of the Rule
We are required by Executive Orders 12866 and 12988 and by the
Presidential Memorandum of June 1, 1998, to write all rules in plain
language. This means that each rule we publish must:
(1) Be logically organized;
(2) Use the active voice to address readers directly;
(3) Use clear language rather than jargon;
(4) Be divided into short sections and sentences; and
(5) Use lists and tables wherever possible.
If you feel that we have not met these requirements, send us
comments by one of the methods listed in ADDRESSES. To better help us
revise the rule, your comments should be as specific as possible. For
example, you should tell us the numbers of the sections or paragraphs
that are unclearly written, which sections or sentences are too long,
the sections where you feel lists or tables would be useful, etc.
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
Regulations adopted pursuant to section 4(a) of the Act are exempt
from the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et
seq.) and do not require an environmental analysis under NEPA. We
published a notice outlining our reasons for this determination in the
Federal Register on October 25, 1983 (48 FR 49244). This includes
listing, delisting, and reclassification rules, as well as critical
habitat designations and species-specific protective regulations
promulgated concurrently with a decision to list or reclassify a
species as threatened. The courts have upheld this position (e.g.,
Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995) (critical
habitat); Center for Biological Diversity v. U.S. Fish and Wildlife
Service, 2005 WL 2000928 (N.D. Cal. Aug. 19, 2005) (concurrent 4(d)
rule)).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations with Native American Tribal
Governments; 59 FR 22951, May 4, 1994), Executive Order 13175
(Consultation and Coordination with Indian Tribal Governments), the
President's memorandum of November 30, 2022 (Uniform Standards for
Tribal Consultation; 87 FR 74479, December 5, 2022), and the Department
of the Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with Federally recognized
Tribes and Alaska Native Corporations (ANCs) on a government-to-
government basis. In accordance with Secretary's Order 3206 of June 5,
1997 (American Indian Tribal Rights, Federal-Tribal Trust
Responsibilities, and the Endangered Species Act), we readily
acknowledge our responsibilities to work directly with Tribes in
developing programs for healthy ecosystems, to acknowledge that Tribal
lands are not subject to the same controls as Federal public lands, to
remain sensitive to Indian culture, and to make information available
to Tribes. We have determined that no Tribal lands fall within the
range of the Alabama hickorynut or Obovaria cf. unicolor, and no Tribes
will be affected if we list these species.
References Cited
A complete list of references cited in this rulemaking is available
on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a> and upon request from
the Alabama Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
Authors
The primary authors of this proposed rule are the staff members of
the Fish and Wildlife Service's Species Assessment Team and the Alabama
Ecological Services Field Office.
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Plants,
Reporting and recordkeeping requirements, Transportation, Wildlife.
Proposed Regulation Promulgation
Accordingly, we propose to amend part 17, subchapter B of chapter
I, title 50 of the Code of Federal Regulations, as set forth below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; and 4201-4245, unless
otherwise noted.
0
2. In Sec. 17.11, amend paragraph (h) by adding entries for
``Hickorynut, [no common name]'' and ``Hickorynut, Alabama'' to the
List of Endangered and Threatened Wildlife in alphabetical order under
CLAMS 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
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Hickorynut, [no common name].. Obovaria cf. Wherever found........ T [Federal Register citation
unicolor. when published as a final
rule]; 50 CFR
17.45(i).\4d\
Hickorynut, Alabama........... Obovaria unicolor Wherever found........ E [Federal Register citation
when published as a final
rule].
* * * * * * *
----------------------------------------------------------------------------------------------------------------
[[Page 73349]]
0
3. Further amend Sec. 17.45, as proposed to be amended on March 20,
2023, at 88 FR 16776 and on July 26, 2023, at 88 FR 48294, by adding
paragraph (i) to read as follows:
Sec. 17.45 Species-specific rules--snails and clams.
* * * * *
(i) Hickorynut, [no common name] (Obovaria cf. unicolor)--(1)
Prohibitions. The following prohibitions that apply to endangered
wildlife also apply to Obovaria cf. unicolor. Except as provided under
paragraph (i)(2) of this section and Sec. Sec. 17.4 and 17.5, it is
unlawful for any person subject to the jurisdiction of the United
States to commit, to attempt to commit, to solicit another to commit,
or cause to be committed, any of the following acts in regard to this
species:
(i) Import or export, as set forth at Sec. 17.21(b) for endangered
wildlife.
(ii) Take, as set forth at Sec. 17.21(c)(1) for endangered
wildlife.
(iii) Possession and other acts with unlawfully taken specimens, as
set forth at Sec. 17.21(d)(1) for endangered wildlife.
(iv) Interstate or foreign commerce in the course of a commercial
activity, as set forth at Sec. 17.21(e) for endangered wildlife.
(v) Sale or offer for sale, as set forth at Sec. 17.21(f) for
endangered wildlife.
(2) Exceptions from prohibitions. In regard to this species, you
may:
(i) Conduct activities as authorized by a permit under Sec. 17.32.
(ii) Take, as set forth at Sec. 17.21(c)(3) and (4) for endangered
wildlife.
(iii) Take, as set forth at Sec. 17.31(b).
(iv) Possess and engage in other acts with unlawfully taken
wildlife, as set forth at Sec. 17.21(d)(2) for endangered wildlife.
(v) Take incidental to an otherwise lawful activity caused by:
(A) Channel and bank restoration projects for creation of natural,
physically stable, ecologically functioning streams, taking into
consideration connectivity with floodplain and groundwater aquifers.
Stream bank restoration projects require planting appropriate native
vegetation, including woody species appropriate for the region and
habitat.
(B) Silviculture practices and forest management activities that
implement State-approved best management practices to protect water and
sediment quality and stream and riparian habitat.
(C) Transportation projects that avoid or do not include activities
that disturb instream habitat, including, but not limited to, bridge
designs that span the stream and avoid stream bank disturbance.
Martha Williams,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2024-20158 Filed 9-9-24; 8:45 am]
BILLING CODE 4333-15-P
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</html>Indexed from Federal Register on September 10, 2024.
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