Endangered and Threatened Wildlife and Plants; Endangered Status for the Neosho Mucket and Threatened Status for the Rabbitsfoot, 57076-57097 [2013-22245]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 78, Number 180 (Tuesday, September 17, 2013)]
[Rules and Regulations]
[Pages 57076-57097]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-22245]



[[Page 57076]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2012-0031; 4500030113]
RIN 1018-AX73


Endangered and Threatened Wildlife and Plants; Endangered Status 
for the Neosho Mucket and Threatened Status for the Rabbitsfoot

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
the Neosho mucket, a freshwater mussel, as endangered, and the 
rabbitsfoot, a freshwater mussel, as threatened, under the Endangered 
Species Act. The Neosho mucket occurs in Arkansas, Kansas, Missouri, 
and Oklahoma. The rabbitsfoot occurs in Alabama, Arkansas, Georgia, 
Illinois, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, 
Ohio, Oklahoma, Pennsylvania, Tennessee, and West Virginia. This final 
rule implements the protections provided by the Act for these species. 
We will issue a final determination on the designation of critical 
habitat for these species in the near future.

DATES: This rule becomes effective October 17, 2013.

ADDRESSES: This final rule is available on the Internet at https://www.regulations.gov and at the Arkansas Ecological Services Office. 
Comments and materials received, as well as supporting documentation 
used in the preparation of this rule, are available for public 
inspection at https://www.regulations.gov. All of the comments, 
materials, and documentation that we considered in this rulemaking are 
available by appointment, during normal business hours at: U.S. Fish 
and Wildlife Service, Arkansas Ecological Service Office, 110 South 
Amity Road, Suite 300, Conway, AR 72032, telephone 501-513-4470 or 
facsimile 501-513-4480.

FOR FURTHER INFORMATION CONTACT: James F. Boggs, Field Supervisor, 
Arkansas Ecological Services Office, 110 South Amity Road, Suite 300, 
Conway, AR 72032, by telephone 501-513-4470 or by facsimile 501-513-
4480. Persons who use a telecommunications device for the deaf (TDD), 
may call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Endangered Species Act 
(Act), a species may warrant protection through listing if it is 
endangered or threatened throughout all or a significant portion of its 
range. Listing a species as an endangered or threatened species can 
only be completed by issuing a rule. We will issue a final 
determination on the designation of critical habitat for the Neosho 
mucket and rabbitsfoot under the Act in the near future.
    The basis for our action. Under the Act, we can determine that a 
species is an endangered or threatened species based on any of five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. We have determined that both species are 
threatened by destruction, modification, or curtailment of habitat or 
range (Factor A), inadequate existing regulatory mechanisms (Factor D), 
and other manmade factors (Factor E).
    Peer review and public comment. We sought comments from three 
independent specialists to ensure that our designation is based on 
scientifically sound data, assumptions, and analyses. We invited these 
peer reviewers to comment on our listing proposal. The peer reviewers 
generally concurred with our methods and conclusions and provided 
additional information, clarifications, and suggestions to improve the 
final listing rule. We also considered all comments and information 
received during the comment periods.

Previous Federal Actions

    Please refer to the proposed listing rule for the Neosho mucket 
(Lampsilis rafinesqueana) and rabbitsfoot (Quadrula cylindrica 
cylindrica) (October 16, 2012; 77 FR 63440) for a detailed description 
of previous Federal actions concerning these species.

Summary of Comments and Recommendations

    We requested written comments from the public on the proposed 
listing rule for the Neosho mucket and rabbitsfoot during two comment 
periods. The first comment period, starting with the publication of the 
proposed rule (77 FR 63440), opened on October 16, 2012, and closed on 
December 17, 2012. The second comment period, starting with the 
publication of the notice of availability for the draft economic 
analysis and draft environmental assessment (78 FR 27171) opened on May 
9, 2013, and closed on June 10, 2013. We held public information 
meetings in Joplin, Missouri, on May 21, 2013, and Greenville, 
Missouri, on May 23, 2013. We did not receive any requests for a public 
hearing during either comment period. We also contacted appropriate 
Federal, State, and local agencies, scientific organizations, and other 
interested parties and invited them to comment on the proposed rule. In 
addition, we published a total of 27 legal public notices in the States 
affected by the listing of both species. All substantive information 
provided during the comment periods has either been incorporated 
directly into this final determination or is addressed below.

Peer Reviewer Comments

    In accordance with our peer review policy published on July 1, 1994 
(59 FR 34270), we solicited expert opinion from three knowledgeable 
individuals with scientific expertise on freshwater mussel conservation 
and biology, with familiarity of Neosho mucket and rabbitsfoot, the 
geographic region and river basins in which they occur, and 
conservation biology principles associated with the species. We 
received responses from all of the peer reviewers we contacted.
    We reviewed all comments received from the peer reviewers for 
substantive issues and new information regarding the listing of Neosho 
mucket and rabbitsfoot. The peer reviewers generally concurred with our 
methods and conclusions and provided additional information, 
clarifications, and suggestions to improve the final listing rule. Peer 
reviewer comments on the listing of the mussels are addressed in the 
following summary and incorporated into this final rule as appropriate.
    (1) Comment: One peer reviewer suggested that we discuss the lure 
used by rabbitsfoot to attract its fish hosts and redefine the 
marsupium as a ``brooding pouch'' rather than a ``pouch''.
    Our Response: We incorporated language to address this topic under 
the Background section of this final determination.
    (2) Comment: One peer reviewer questioned whether the Act and its 
implementing regulations set forth a series of general prohibitions and 
exceptions that apply to threatened wildlife the same as endangered 
wildlife.

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    Our Response: The prohibitions of section 9(a)(1) of the Act, 
incorporated into our regulations at 50 CFR 17.21, make it illegal for 
any person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect, or to attempt any of these), import, export, ship 
in interstate commerce in the course of commercial activity, or sell or 
offer for sale in interstate or foreign commerce any species listed as 
endangered. Our regulations at 50 CFR 17.31 contain the same 
prohibitions for species listed as threatened, unless exceptions are 
made in a rule issued under section 4(d) of the Act.
    (3) Comment: One peer reviewer suggested Neosho mucket and 
rabbitsfoot are thermally sensitive because closely related mussel 
species, such as pimpleback (Quadrula pustulosa), pistolgrip (Quadrula 
verrucosa), plain pocketbook (Lampsilis cardium), and yellow sandshell 
(Lampsilis teres), are known to be thermally sensitive, although no 
physiological thermal tolerance data is available for Neosho mucket and 
rabbitsfoot.
    Our Response: We agree that the best available scientific 
information indicates that Neosho mucket and rabbitsfoot may be 
thermally sensitive and added language to address the topic under 
Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence--Temperature section of this final determination.
    (4) Comment: One peer reviewer suggested there is substantial 
evidence the interaction of climate warming and water management is 
negatively affecting mussels in the south-central United States.
    Our Response: We agree that a combination of climate patterns and 
local water management practices (e.g., reduced reservoir releases) led 
to shifts in the species richness and overall abundance of mussel 
assemblages dominated by thermally sensitive to thermally tolerant 
species in southeast Oklahoma. We incorporated language to address this 
topic under Factor E. Other Natural or Manmade Factors Affecting Its 
Continued Existence--Temperature section of this final determination.
    (5) Comment: One peer reviewer suggested poultry production is a 
potential threat to Neosho mucket and rabbitsfoot in the Little River 
basin.
    Our Response: We agree and incorporated language to address the 
topic under Factor A. The Present or Threatened Destruction, 
Modification, or Curtailment of its Habitat or Range--Chemical 
Contaminants section of this final determination.
    (6) Comment: One peer reviewer recommended we include rabbitsfoot 
density information for the Little River from Galbraith and Vaughn 
(2011). This reviewer also recommended we include information from 
Galbraith (2009) on the effects of water temperature to rabbitsfoot.
    Our Response: We agree and incorporated language to address the 
topic in the Taxonomy, Life History, and Distribution section for 
Rabbitsfoot and under Factor E. Other Natural or Manmade Factors 
Affecting Its Continued Existence--Temperature section of this final 
determination.
    (7) Comment: One peer reviewer recommended we include detailed 
anatomy of the rabbitsfoot information provided by Williams et al. 
(2008). This peer reviewer also noted several scientific citations 
omitted from the proposed rule that pertain to historical and modern 
rabbitsfoot records in the Tennessee River, lower Duck River, Ohio 
River, and Monongahela River.
    Our Response: While not directly cited in the proposed rule, Butler 
(2005) cited several of the citations provided by the peer reviewer, 
and, accordingly, they are incorporated in the Service's analysis and 
administrative record. Our assessment of the rabbitsfoot population 
indicates extirpation in the Monongahela River occurred circa 1890 and 
is consistent with Ortmann (1919). We incorporated the other citations 
provided by the peer reviewer (related to soft anatomy and rabbitsfoot 
distribution) to address the topic in the Summary of Biological Status 
and Threats section for rabbitsfoot into this final determination.
    (8) Comment: One peer reviewer noted the rainbow darter (Etheostoma 
caeruleum) is a host fish for rabbitsfoot.
    Our Response: We agree and incorporated language to address the 
topic in the Summary of Biological Status and Threats section for 
rabbitsfoot of this final determination.
    (9) Comment: One peer reviewer suggested it would be prudent to add 
the work by Vaughn and Taylor (1999) on dams and their downstream 
effects to freshwater mussels.
    Our Response: We agree and incorporated language to address the 
topic under Factor A. The Present or Threatened Destruction, 
Modification, or Curtailment of its Habitat or Range--Impoundments 
section of this final determination.

Federal Agency Comments

    (10) Comment: The U.S. Army Corps of Engineers Pittsburgh District 
(COEPD) indicated listing of rabbitsfoot may affect the COEPD's 
navigation and maintenance dredging activities in the Allegheny River, 
its operation of Allegheny Reservoir, and its regulatory program. They 
indicate additional avoidance measures will be required to adequately 
protect rabbitsfoot and its habitat.
    Our Response: The federally endangered clubshell (Pleurobema 
clava), northern riffleshell (Epioblasma torulosa rangiana), rayed bean 
(Villosa fabalis), and snuffbox (Epioblasma triquetra) mussels occur in 
the same reach of the Allegheny River as rabbitsfoot. Section 7 of the 
Act already requires Federal agencies to consult with the Service to 
ensure that any action authorized, funded, or carried out will not 
likely jeopardize the continued existence of these listed species. 
Project modifications that minimize effects to these listed mussel 
species also would minimize effects to rabbitsfoot. Thus, we would not 
expect additional conservation measures and costs for the rabbitsfoot 
over what are already required for these other endangered mussels.
    (11) Comment: The COEPD asked how tributary streams will be 
affected by the listing of rabbitsfoot.
    Our Response: The listing of the rabbitsfoot will occur in 15 
States. We are unable to definitively determine how many tributary 
streams will be covered by the final designation. Section 7 of the Act 
requires Federal agencies to consider direct, indirect, and cumulative 
effects to listed species. The Service will work with COEPD to 
determine whether any of the current, ongoing or planned COEPD projects 
may have direct, indirect, or cumulative effects on tributaries within 
their District. As stated previously, the Service does not expect 
additional project modifications to minimize effects to rabbitsfoot 
beyond those already required for other listed mussels in the Allegheny 
River basin.
    (12) Comment: The COEPD indicated stakeholders in the sand and 
gravel industry rely on an Adaptive Management Group Mussel Survey 
Protocol and conclude the protocol will need to be revised to include 
rabbitsfoot.
    Our Response: This protocol is for use only in the impounded 
Allegheny River navigation channel (river mile 0 to near 65) and Ohio 
River navigation channel in Pennsylvania (river mile 0 to 40). While 
this area is within the range of the rabbitsfoot, it has been more than 
80 years since a rabbitsfoot specimen was found in this reach of the 
river. Nevertheless, we agree the protocol will

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need to be revised to include rabbitsfoot. However, in the past using 
the protocol has failed to locate the federally listed northern 
riffleshell and clubshell mussels while others sampling the same 
location using a different method have detected them. In addition, 
these mussels tend to be more difficult to locate than rabbitsfoot. 
Therefore, the protocol should be revised because of its apparent lack 
of effectiveness regardless of whether rabbitsfoot is listed under the 
Act.

State Agency Comments

    The listing for the Neosho mucket covers Arkansas, Kansas, 
Missouri, and Oklahoma and for rabbitsfoot covers Alabama, Arkansas, 
Georgia, Kansas, Kentucky, Illinois, Indiana, Louisiana, Mississippi, 
Missouri, Ohio, Oklahoma, Pennsylvania, Tennessee, and West Virginia. 
We received comments from the States of Louisiana, Pennsylvania, Ohio, 
and Oklahoma regarding the proposal.
    (13) Comment: The Pennsylvania Fish and Boat Commission (PFBC) 
supports the listing. PFBC concluded that golden alga (Prymnesium 
parvum) is an invasive species that has the potential to threaten the 
existing Shenango River rabbitsfoot population based on work by Barkoh 
and Fries (2010).
    Our Response: We appreciate the support and look forward to 
continuing work with the PFBC to recover rabbitsfoot. We agree that 
golden alga is a threat to rabbitsfoot in the Shenango River and 
incorporated language to address the topic under Factor E. Other 
Natural or Manmade Factors Affecting Its Continued Existence--Invasive 
Nonindigenous Species section of this final determination.
    (14) Comment: The Oklahoma Department of Wildlife Conservation 
(ODWC) asserts the decline of rabbitsfoot geographic range is not a 
recent phenomenon, but rather a gradual decline over a century. It 
provided a breakdown of extirpation dates based on table 2 in the 
proposed rule, with 10 percent of those extirpations occurring prior to 
1900; 26 percent from 1900 to 1930; 11 percent from 1930 to 1960; and 
34 percent from 1960 to 1980, or 81 percent of the total extirpations 
occurring prior to 1980. ODWC concludes it is uncertain which factors 
contributed to earlier extirpations, but some threats may have been 
ameliorated in the intervening decades. It further contends the 
relative magnitude and importance of each threat is not adequately 
quantified (speculative and not supported by empirical data) for extant 
or extirpated rabbitsfoot populations.
    Our Response: In determining which of the listing factors contained 
in Section 4 of the Act justified listing the species, we used 
information on the biology, ecology, distribution, abundance, status, 
and trends of each species from a wide variety of sources. These 
sources included professional journal articles, distributional status 
surveys, biological assessments, and other unpublished material (that 
is, ``gray literature'') from State natural resource agencies and 
natural heritage programs, Tribal governments, other Federal agencies, 
consulting firms, contractors, and individuals associated with 
professional organizations and higher educational institutions.
    Although we have sporadic documentation of rabbitsfoot collections 
from the last century, as discussed under the Status Assessment for 
Neosho Mucket and Rabbitsfoot and Summary of Factors Affecting the 
Species sections in the proposed rule, rangewide trends indicate 
declining populations and, despite attempts at some locations to 
alleviate threats, no population is without threats significantly 
affecting the species. These threats are expected to be exacerbated by 
increased water demand, habitat degradation, and climate change in the 
future (Spooner and Vaughn 2008; Galbraith et al. 2010). We 
respectfully disagree that available scientific information supports 
the conclusion that threats have been ameliorated in many historical 
rivers throughout the entirety of the species range. Each threat is 
discussed in detail in the Summary of Factors Affecting the Species and 
is further summarized in the Summary of Biological Status and 
Determination sections of this final determination.
    (15) Comment: The ODWC does not support listing rabbitsfoot as 
threatened. The ODWC asserts that listing is premature and may impede 
conservation strategies such as augmenting and reestablishing 
populations. It also contends that the rapid elevation of rabbitsfoot 
from candidate status in 2009 to a proposed threatened species in 2012 
is premature and did not include sufficient coordination with the State 
of Oklahoma. The ODWC also concludes that 51 extant rabbitsfoot 
populations, albeit most of which are small and declining, are 
sufficient to preclude listing as a threatened species.
    Our Response: The Act requires that we identify species of wildlife 
and plants that are endangered or threatened based on the best 
available scientific information. As defined in section 3 of the Act, a 
threatened species is any species which is likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range. As part of our program to add species 
to the list of threatened and endangered wildlife, we also maintain a 
list of species which are candidates for listing. A candidate species 
is one for which we have sufficient information on biological 
vulnerability and threats to support a proposal to list as endangered 
or threatened, but for which preparation and publication of a rule is 
precluded by higher priority listing actions.
    The rabbitsfoot was added to our candidate list in 2009 (75 FR 
69222) and has remained on the candidate list through our most recent 
candidate notice of review (CNOR) in 2012 (77 FR 70054). Additionally, 
the Service presented a rangewide status assessment and overview of the 
proposed listing process for rabbitsfoot at the Interior Highlands 
Mollusk Conservation Council (IHMCC) annual meeting in 2011 and 2012. 
We sent out requests in 2008, 2009, and 2010 to the Unio list serve 
maintained by the Freshwater Mollusk Conservation Society requesting 
information on the status of rabbitsfoot populations and threats. We 
sent a letter dated March 15, 2011, to interested parties in Oklahoma 
including the ODWC. The Service has received numerous responses to 
these inquiries and our efforts to reach out to the agencies, Tribes, 
organizations, and academia to solicit information and input.
    While the rabbitsfoot still occurs in 51 streams, it sustains 
recruitment and population viability consistently in only 11 large, 
extant river populations. This accounts only for 8 percent of the 
historical or 22 percent of the extant distribution of rabbitsfoot. 
Further, the species also sustains limited recruitment and distribution 
in another 17 river populations, of which 15 (88 percent) are 
declining. The synergistic effects of threats discussed in the proposed 
rule and this final determination are often complex in aquatic 
environments and, while making it difficult to predict changes in 
mussel and fish host(s) distribution, abundance, and habitat 
availability, it is probable that these threats are acting 
simultaneously on the remaining rabbitsfoot populations with negative 
results and are expected to continue to do so based on the best 
available scientific information. Based on this information and 
information provided in our above response, we believe there is 
sufficient scientific information to support our final determination of 
listing rabbitsfoot as a threatened species.

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    (16) Comment: ODWC requested that the Service delay listing of the 
rabbitsfoot until the final year (2016) of the Multi-District 
Litigation (MDL) settlement and listing workplan.
    Our Response: The multiyear listing workplan was developed through 
a settlement agreement with plaintiff groups to resolve multidistrict 
litigation. It is an effort to improve implementation of the Act while 
adhering to our court-approved obligations under the settlement 
agreement. The listing workplan enables the Service to systematically 
review and address the needs of more than 250 species listed on the 
2010 CNOR and determine if they should be added to the Federal Lists of 
Endangered and Threatened Wildlife and Plants. The listing workplan has 
established deadlines for each candidate species, including the 
rabbitsfoot. In making this final determination at this time, the 
Service is adhering to the requirements of the listing workplan and 
settlement agreement. Additionally, the Act requires that we make a 
final listing determination within 1 year of a proposal. Therefore, we 
cannot postpone a final determination.
    (17) Comment: ODWC contends that implementation of recovery 
efforts, particularly population augmentation and reintroduction, for 
the rabbitsfoot will be more cumbersome due to lack of public support 
compared to nonlisted species.
    Our Response: We believe that listing either mussel will not impede 
progress with ongoing or future population augmentation and 
reintroduction efforts or hinder our ability to recover the species. We 
agree that some property owners are reluctant to work with the Service 
and our partners to conduct conservation on their lands due to fear of 
future property use restrictions related to the Act. To address this 
concern, the Service has various programs that provide regulatory 
assurance for property owners. For example, the Safe Harbor Agreement 
program provides assurances to non-Federal landowners that future 
property use limitations will not occur without the property owner's 
consent, if voluntary conservation measures they implement on their 
property provide a net conservation benefit to the recovery of a listed 
species.
    Further, we believe that listing the species will make additional 
conservation resources available. Although we are unaware of any 
ongoing efforts to augment or reestablish mussel populations in 
Oklahoma, many States (such as, Missouri, Kansas, Kentucky, Tennessee, 
Alabama, and Ohio) have successful propagation, augmentation, and 
reintroduction efforts ongoing for threatened and endangered mussels. 
In accordance with Service policy (65 FR 56916), the Service will work 
with our partners to develop a propagation, augmentation, and 
reintroduction plan for the Neosho mucket and rabbitsfoot to help 
ensure smooth transitions between various phases of conservation 
efforts. The Service is committed to these conservation efforts and 
looks forward to working closely with the State of Oklahoma and our 
other conservation partners to permit such efforts under section 
10(a)(1)(A) of the Act. In addition, pursuant to section 6 of the Act, 
Oklahoma as well as the other States within the range of the 
rabbitsfoot would be eligible for Federal funds to implement management 
actions that promote the protection or recovery of the rabbitsfoot 
(https://www.fws.gov/grants).
    (18) Comment: The Pennsylvania Department of Transportation (PDOT) 
opposes listing the rabbitsfoot as threatened due to the financial 
hardship it will bring to Pennsylvania taxpayers. PDOT concludes it is 
not a prudent use of transportation dollars to consult with the 
Service.
    Our Response: Listing the rabbitsfoot under the Act must be based 
on the five listing factors (threats to the species), which do not 
include economic impacts. Critical habitat designation does require the 
Service to consider economic impacts, but that will be addressed in the 
rule to designate critical habitat for both mussels, which will be 
published at a later date.
    (19) Comment: PDOT requested minor road work (such as 
rehabilitation or resurfacing) and bridge work (such as replacement and 
repair) on existing roads be exempt (sic) from formal coordination 
(consultation), including areas 100 feet upstream and downstream of the 
project footprint.
    Our Response: All PDOT activities authorized or funded, in whole or 
part, by the Federal Highway Administration (FHWA) or permitted (such 
as, placement of bridge piers in a navigable stream) by a Federal 
agency such as the U.S. Army Corps of Engineers (Corps) are required to 
adhere to the consultation requirements of section 7(a)(2) of the Act, 
regardless of size. However, once the rabbitsfoot is listed, the 
Service can work with PDOT and FHWA or other Federal agencies to 
prepare a programmatic consultation that would address routine highway 
maintenance and other regular projects, thereby streamlining the 
consultation process and reducing associated costs.
    (20) Comment: PDOT states that it issues road posting, bonding, and 
hauling permits to hauling industries for the purpose of protecting 
secondary roads from vehicle damage. PDOT acknowledges its potential 
liability under section 9 of the Act in the event that a hauling 
industry permittee has an accidental spill resulting in take of 
rabbitsfoot. They conclude that the Service operating under its mandate 
to err conservatively to protect species may be considering all road 
crossings as posing a threat of chemical contamination from spills. 
They conducted an analysis of their aforementioned program and provided 
information to refine our analysis of threats associated with chemical 
contaminants, but only identify one conflict of road bonding at State 
Road 2005 in Crawford County, Pennsylvania.
    Our Response: The Service appreciates PDOT's willingness to provide 
an analysis of their road posting, bonding, and hauling permit program. 
There are instances where chemical spills have resulted in the loss of 
high numbers of mussels (Jones et al. 2001, p. 20; Brown et al. 2005, 
p. 1457; Schmerfeld 2006, pp. 12-13), and are considered a serious 
threat to mussel species. Therefore, chemical spills are identified as 
a threat to rabbitsfoot. The Service conducted an examination of land 
use trends, nonpoint- and point-source discharges, and determined that 
rabbitsfoot is subjected to the subtle, pervasive effects of chronic, 
low-level contamination that is ubiquitous in watersheds where it 
occurs. The Service has reviewed the information provided by PDOT and 
incorporated it into this rule where applicable. However, this 
information does not change our conclusion that biological and habitat 
effects due to chemical contaminants are a significant and ongoing 
threat contributing to the decline of rabbitsfoot populations.
    (21) Comment: PDOT expressed concern with its ability to quickly 
issue hauling permits for oversize and overweight loads and restrict 
routing for materials such as fracking brine. It asserts that a need to 
restrict routing for a subset of haulers such as hazardous material 
haulers would preclude its ability to electronically permit and route 
these haulers, thus resulting in extensive time delays and subsequently 
a need for a significant increase in manpower. PDOT concludes that 
manual permit review to minimize section 9 liability that would result 
from listing rabbitsfoot represents a significant economic burden to 
both the State of Pennsylvania and many

[[Page 57080]]

industries because of needed increases in manpower to process permits.
    Our Response: Listing the Neosho mucket and rabbitsfoot under the 
Act must be based on the five listing factors (threats to the species), 
which do not include economic impacts. Critical habitat designation 
does require the Service to consider economic impacts, but that will be 
addressed in the rule to designate critical habitat for both mussels 
which will be published at a later date.
    Further, as discussed above (response to Comment 10), the federally 
endangered clubshell (Pleurobema clava), northern riffleshell 
(Epioblasma torulosa rangiana), rayed bean (Villosa fabalis), and 
snuffbox (Epioblasma triquetra) occur in the same reach of the 
Allegheny and Shenango Rivers and French and Muddy Creeks as 
rabbitsfoot. Project modifications and conservation efforts that 
minimize effects to these listed mussel species also would minimize 
effects to rabbitsfoot. Therefore, we do not believe the listing of 
rabbitsfoot would increase PDOT's section 9 liability on the State of 
Pennsylvania and industries transporting hazardous materials. However, 
as noted previously, the Service can work with PDOT to prepare 
standardized conservation measures that address the transportation of 
hazardous material and would minimize effects to rabbitsfoot and other 
federally protected mussels.

Public Comments

    (22) Comment: One commenter requested that Neosho mucket and 
rabbitsfoot should not be removed from the Federal List of Endangered 
and Threatened Wildlife.
    Our Response: We believe the commenter may have misunderstood the 
intent of the proposed rule. We wish to clarify that we proposed adding 
Neosho mucket and rabbitsfoot to the Federal List of Endangered and 
Threatened Wildlife and Plants, not removing them.
    (23) Comment: One commenter suggested we should focus our efforts 
more on the Indiana bat rather than mussels.
    Our Response: The Act requires that we list species that meet the 
definition of threatened or endangered. According to the best available 
science, the Neosho mucket and rabbitsfoot meet the criteria for 
listing and, therefore, we are required by the Act to list them. The 
Indiana bat (Myotis sodalis) was federally listed as endangered 
throughout its range under the Endangered Species Preservation Act of 
1966 on March 11, 1967, and remains listed as endangered under the Act. 
Consistent with this status, the Service is focusing efforts on the 
bat: the Service has approved a recovery plan for the Indiana bat, and 
we are currently working with our partners to implement recovery 
actions specified in that recovery plan.
    (24) Comment: One commenter stated the economic benefits of large 
impoundments and channelization projects outweigh the adverse effects 
to Neosho mucket and rabbitsfoot populations.
    Our Response: Listing the Neosho mucket and rabbitsfoot under the 
Act must be based on the five listing factors (threats to the species), 
which do not include economic impacts. Critical habitat designation 
does require the Service to consider economic impacts, but that will be 
addressed in the rule to designate critical habitat for both mussels, 
which will be published at a later date.
    (25) Comment: One commenter was concerned that private landowner 
water development projects, development of or modification of livestock 
and irrigation water rights, normal farming and ranching activities, 
and development of mineral rights on private property may trigger 
section 7 consultations. The commenter asked whether these activities 
on private property represent a federal nexus and thereby are subject 
to section 7 consultation.
    Our Response: The effects of private activities, such as normal 
operations for rearing of livestock, farming, and modification of water 
rights and development of mineral rights are not subject to the Act's 
section 7 consultation requirements unless they are connected to a 
Federal action (require Federal permits, are federally funded, or are a 
Federal action).

Summary of Changes From the Proposed Rule

    The information below is provided as a result of the peer and 
public review process. In this final determination, we have made 
changes to the discussion of biological status and threats for both 
mussels from the proposed rule. We have clarified that the rabbitsfoot 
uses all four gills as a marsupium or ``brooding pouch'' rather than 
``pouch'' for its glochidia (Fobian 2007, p. 26). Watters et al. (2009, 
p. 269) reported the rainbow darter (E. caeruleum) as a host fish for 
rabbitsfoot, but we did not cite it in the proposed rule. Also, newly 
included is information on the status of the rabbitsfoot in the Red 
River basin. In addition, new information related to the factors 
(threats) affecting Neosho mucket and rabbitsfoot has been added. This 
includes information on thermal tolerance and effects of impoundments, 
chemical contaminants, climate change, and invasive nonindigenous 
species to mussels, discussed in the Summary of Factors Affecting the 
Species, Factor A. The Present or Threatened Destruction, Modification, 
or Curtailment of its Habitat or Range--Chemical Contaminants and 
Impoundments and Factor E. Other Natural or Manmade Factors Affecting 
Its Continued Existence--Temperature and Climate Change.

Background

    Please refer to the proposed listing rule for the Neosho mucket and 
rabbitsfoot (October 16, 2013, 77 FR 63440) for a summary of species 
information.

Summary of Biological Status

    For more information on relative abundance and trends of extant 
populations of Neosho mucket and rabbitsfoot by river basin please 
refer to the Taxonomy, Life History, and Distribution section of the 
proposed rule published in the Federal Register on October 16, 2012 (77 
FR 63440).
    Our assessment evaluated the biological status of these species and 
threats affecting their continued existence. It was based upon the best 
available scientific and commercial data and expert opinions.
    The Neosho mucket is declining rangewide, with the exception of one 
population. Based on historical and current data, Neosho mucket has 
been extirpated from approximately 1,342 rkm (834 rmi) of its 
historical range (62 percent). Most of this extirpation has occurred 
within the Oklahoma and Kansas portions of its range. The extirpation 
of this species from numerous streams and stream reaches within its 
historical range signifies that substantial population losses have 
occurred. Extant populations are disjunct (not contiguous) in 
approximately 819 rkm (509 rmi). The Spring River in Missouri supports 
the only viable population based on the presence of a large number of 
individuals and evidence of recent recruitment. Given this compilation 
of current distribution, abundance, and status trend information, the 
Neosho mucket exhibits range reductions and population declines 
throughout its range.
    Based on historical and current data, the rabbitsfoot is declining 
rangewide. In 10 of the 15 States comprising the rabbitsfoot's 
historical range, the species is considered by State law to be

[[Page 57081]]

endangered (Illinois, Indiana, Kansas, Mississippi, Ohio, and 
Pennsylvania); threatened (Kentucky and Tennessee); of special concern 
(Arkansas); or it is assigned an uncategorized conservation status 
(Alabama). The American Malacological Union and American Fisheries 
Society also consider the rabbitsfoot to be threatened (in Butler 2005, 
p. 21). It is presently extant in 51 of the 141 streams of historical 
occurrence, a 64 percent decline. Further, in the streams where it is 
extant, populations with few exceptions are highly fragmented and 
restricted to short reaches. We add this information, which was not in 
the proposed rule, on the rabbitsfoot in streams within the Red River 
basin. The Red River basin streams primarily drain the Ouachita 
Mountains in southeastern Oklahoma and southwestern Arkansas and 
northern Louisiana; extant populations of rabbitsfoot still occur in 
three stream reaches within the Gulf Coastal Plain ecoregion in 
southern Arkansas, southeastern Oklahoma, and northern Louisiana. In 
addition to the density information published in the proposed rule, we 
add this information on rabbitsfoot density in Oklahoma, which was not 
in the proposed rule. Rabbitsfoot density ranged from 0.3 to 2.4 
individuals per square meter at three sites in Oklahoma (Galbraith and 
Vaughn 2011, p. 197) in the Red River basin. In addition, the species 
has been extirpated from West Virginia and Georgia. The extirpation of 
this species from numerous streams and stream reaches within its 
historical range signifies that substantial population losses have 
occurred in each of the past several decades.
    Seventeen streams (33 percent of extant populations or 12 percent 
of historical populations) have small populations with limited levels 
of recruitment and are generally highly restricted in distribution, 
making their viability unlikely and making them extremely susceptible 
to extirpation in the near future. In addition, 15 of those 17 streams 
(88 percent) have populations that are declining. In many of these 
streams, rabbitsfoot is only known from one or two documented 
individuals in the past decade. Its viability in these streams is 
doubtful, and additional extirpations may occur if this downward 
population trend continues. Eleven populations (22 percent of extant 
populations or 8 percent of historical populations; Ohio, Green, 
Tippecanoe, Tennessee, Paint Rock, Duck, White, Black, Strawberry, and 
Little Rivers and French Creek) are considered viable (Butler 2005, p. 
88; Service 2010, p. 16). Given this compilation of current 
distribution, abundance, and status trend information, the rabbitsfoot 
exhibits range reductions and population declines throughout its range.

Summary of Factors Affecting the Species

    Section 4 of the Act and its implementing regulations (50 CFR 424) 
set forth the procedures for adding species to the Federal Lists of 
Endangered and Threatened Wildlife and Plants. A species may be 
determined to be an endangered or threatened species due to one or more 
of the five factors described in section 4(a)(1) of the Act: (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. Listing actions may 
be warranted based on any of the above threat factors, singly or in 
combination. Each of these factors is discussed below.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    The habitats of freshwater mussels are vulnerable to water quality 
degradation and habitat modification from a number of activities 
associated with modern civilization. The decline, extirpation, and 
extinction of mussel species are often attributed to habitat alteration 
and destruction (Neves et al. 1997, pp. 51-52). Bogan (1993, pp. 599-
600 and 603-605) linked the decline and extinction of mussels to a wide 
variety of threats including siltation, industrial and municipal 
effluents, modification of stream channels, impoundments, pesticides, 
heavy metals, invasive species, and the loss of host fish. Chief among 
the causes of decline in distribution and abundance of the Neosho 
mucket and rabbitsfoot, and in no particular order of ranking, are 
impoundment, channelization, sedimentation, chemical contaminants, 
mining, and oil and natural gas development (Mather 1990, pp. 18-19; 
Obermeyer et al. 1997b, pp. 113-115; Neves et al. 1997, pp. 63-72; 
Davidson 2011, pers. comm.). Neosho mucket and rabbitsfoot are both 
found within medium to large river drainages exposed to a variety of 
landscape uses. These threats to mussels in general (and Neosho mucket 
and rabbitsfoot where specifically known) are individually discussed 
below.
Impoundments
    Dams eliminate and alter river flow within impounded areas, trap 
silt leading to increased sediment deposition, alter water quality, 
change hydrology and channel geomorphology, decrease habitat 
heterogeneity, affect normal flood patterns, and block upstream and 
downstream movement of mussels and fish (Layzer et al. 1993, pp. 68-69; 
Neves et al. 1997, pp. 63-64; Watters 2000, pp. 261-264). Within 
impounded waters, decline of mussels has been attributed to direct loss 
of supporting habitat, sedimentation, decreased dissolved oxygen, 
temperature levels, and alteration in resident fish populations (Neves 
et al. 1997, pp. 63-64; Pringle et al. 2000, pp. 810-815; Watters 2000, 
pp. 261-264). Downstream of dams, mussel declines are associated with 
changes and fluctuation in flow regime, channel scouring and bank 
erosion, reduced dissolved oxygen levels and water temperatures, and 
changes in resident fish assemblages (Williams et al. 1992, p. 7; 
Layzer et al. 1993, p. 69; Neves et al. 1997, pp. 63-64; Watters 2000, 
pp. 265-266; Pringle et al. 2000, pp. 810-815). Dams that are low to 
the water surface, or have water passing over them (small low head or 
mill dams) can have some of these same effects on mussels and their 
fish hosts, particularly reducing species richness and evenness and 
blocking fish host movements (Watters 2000, pp. 261-264; Dean et al. 
2002, pp. 235-238).
    The decline of mussels within the Arkansas, Red, White, Tennessee, 
Cumberland, Mississippi, and Ohio River basins has been directly 
attributed to construction of numerous impoundments (Miller et al. 
1984, p. 109; Williams and Schuster 1989, pp. 7-10; Layzer et al. 1993, 
pp. 68-69; Neves et al. 1997, pp. 63-64; Obermeyer et al. 1997b, pp. 
113-115; Watters 2000, pp. 262-263; Sickel et al. 2007, pp. 71-78; 
Hanlon et al. 2009, pp. 11-12; Vaughn and Taylor 1999, pp. 915-917; 
Watters and Flaute 2010, pp. 3-7). Population losses due to 
impoundments have likely contributed more to the decline of the Neosho 
mucket and rabbitsfoot than any other factor. River habitat throughout 
the ranges of the Neosho mucket and rabbitsfoot has been impounded, 
leaving short, isolated patches of suitable habitat that sometimes 
lacks suitable fish hosts. Neither Neosho mucket nor rabbitsfoot occur 
in reservoirs lacking riverine characteristics. They are unable to 
successfully reproduce and recruit under these conditions (Obermeyer et 
al. 1997b, p. 114; Butler 2005, p. 96). On the other hand, rabbitsfoot 
may persist

[[Page 57082]]

and even exhibit some level of recruitment in some large rivers with 
locks and dams where appropriate habitat quality and quantity remain 
(Ohio and Tennessee Rivers in riverine reaches between a few locks and 
dams) (Butler 2005, p. 96).
    The majority of the mainstem Ohio, Cumberland, Tennessee, and White 
Rivers and many of their largest tributaries are impounded, in many 
cases resulting in tailwater (downstream of dam) conditions unsuitable 
for rabbitsfoot (Butler 2005, p. 96). There are 36 major dams within 
the Tennessee River basin (Holston, Little Tennessee, Clinch, Elk, 
Flint, and Sequatchie Rivers, and Bear Creek) that have resulted in the 
impoundment of 3,680 rkm (2,300 rmi) of the Tennessee River and its 
largest tributaries (Butler 2005, p. 95). Only three of these rivers 
support viable populations--the Tennessee, Paint Rock, and Duck Rivers. 
Ninety percent of the Cumberland River downstream of Cumberland Falls 
(rkm 866, rmi 550) as well as numerous tributaries are either directly 
impounded or otherwise adversely affected by cold tailwater releases 
from dams.
    Rabbitsfoot and its fish hosts are warm-water species and the 
change in temperature to cold water below the dams further reduces 
suitable habitat for the species and may eliminate fish hosts that 
cannot adapt to colder water temperatures (see the Temperature section 
below for more information). Rabbitsfoot in the Little River, Oklahoma, 
were found at locations farthest from impoundments (Vaughn and Taylor 
1999, p. 915). Mussel species richness and total abundance downstream 
of dams increases as the distance from dams increases. Little River 
mussel populations did not recover from impoundment effects until 20 
rkm (12 rmi) downstream, with a peak of species richness and abundance 
at 53 rkm (33 rmi) downstream of the impoundment (Vaughn and Taylor 
1999, p. 915). Other tributary impoundments that negatively impact 
rabbitsfoot and its fish hosts within the Ohio River basin include, but 
are not limited to, the Walhonding, Barren, Rough, and Eel Rivers and 
two rivers with viable populations, Green and Tippecanoe Rivers. The 
majority (7 of 11 populations or 64 percent) of viable rabbitsfoot 
populations (Ohio, Green, Tippecanoe, Tennessee, Duck, White, and 
Little Rivers) occur downstream of main stem impoundments that make 
these populations more susceptible to altered habitat quality and 
quantity associated with the impoundment or dam operation, which may be 
exacerbated during stochastic events such as droughts and floods.
    Navigational improvements on the Ohio River began in 1830, and now 
include 21 lock and dam structures stretching from Pittsburgh, 
Pennsylvania, to Olmsted, Illinois, near its confluence with the 
Mississippi River. Lock and dam structures convert riverine habitat to 
unsuitable static habitat for the mussel and prevent movement of their 
fish hosts. Numerous Ohio River tributaries also have been altered by 
lock and dam structures. For example, a 116-rkm (72-rmi) stretch of the 
Allegheny River in Pennsylvania has been altered with nine locks and 
dams from Armstrong County to Pittsburgh. A series of six locks and 
dams were constructed on the lower half of the Green River decades ago 
that extend upstream to the western boundary of Mammoth Cave National 
Park, Kentucky. The declines of rabbitsfoot populations are 
attributable to navigational locks and dams on the Ohio, Allegheny, 
Monongahela, Muskingum, Kentucky, Green, Barren, and White Rivers, and 
are widespread throughout the species range.
    Impoundments have eliminated a large portion of the Neosho mucket 
population and habitat in the Arkansas River basin. For example, mussel 
habitat in the Neosho River in Kansas has been negatively impacted by 
at least 15 city dams and 2 Federal dams, both with regulated flows. 
Almost the entire length of the river in Oklahoma is now impounded or 
adversely affected by tailwater releases from three major dams 
(Matthews et al. 2005, p. 308). Several reservoirs and numerous small 
watershed lakes have eliminated suitable mussel habitat in several 
larger Neosho River tributaries in Kansas and Missouri (Spring, Elk, 
and Cottonwood Rivers and Shoal Creek). The Verdigris River (Kansas and 
Oklahoma) has two large reservoirs with regulated flows, and the lower 
section has been channelized as part of the McClellan-Kerr Arkansas 
River Navigation System. All the major Verdigris River tributaries in 
Kansas and Oklahoma have been partially inundated by reservoirs with 
regulated flows and numerous flood control watershed lakes (Obermeyer 
et al. 1995, pp. 7-21). Construction of Lake Tenkiller eliminated 
Neosho mucket populations and habitat in the lower portion of the 
Illinois River, Oklahoma (Davidson 2011, pers. comm.).
    Dam construction has a secondary effect of fragmenting the ranges 
of mussel species by leaving relict habitats and populations isolated 
upstream or between structures as well as creating extensive areas of 
deep uninhabitable, impounded waters. These isolated populations are 
unable to naturally recolonize suitable habitat downstream and become 
more prone to further extirpation from stochastic events, such as 
severe drought, chemical spills, or unauthorized discharges (Layzer et 
al. 1993, pp. 68-69; Cope et al. 1997, pp. 235-237; Neves et al. 1997, 
pp. 63-75; Watters 2000, pp. 264-265, 268; Miller and Payne 2001, pp. 
14-15; Pringle et al. 2000, pp. 810-815; Watters and Flaute 2010, pp. 
3-7). We conclude that habitat effects due to impoundment are an 
ongoing threat to the Neosho mucket and rabbitsfoot.
Channelization
    Dredging and channelization activities have profoundly altered 
riverine habitats nationwide. Hartfield (1993, pp. 131-139), Neves et 
al. (1997, pp. 71-72), and Watters (2000, pp. 268-269) reviewed the 
specific upstream and downstream effects of channelization on 
freshwater mussels. Channelization affects a stream physically 
(accelerates erosion, increases sediment bed load, reduces water depth, 
decreases habitat diversity, creates geomorphic (natural channel 
dimensions) instability, and eliminates riparian canopy) and 
biologically (decreases fish and mussel diversity, changes species 
composition and abundance, decreases biomass, and reduces growth rates) 
(Hartfield 1993, pp. 131-139). Channel modification for navigation has 
been shown to increase flood heights (Belt 1975, p. 684), partly as a 
result of an increase in stream bed slope (Hubbard et al. 1993, p. 
137). Flood events are exacerbated, conveying large quantities of 
sediment, potentially with adsorbed contaminants, into streams. Channel 
maintenance often results in increased turbidity and sedimentation that 
often smothers mussels (Stansbery 1970, p. 10).
    Channel maintenance operations for commercial navigation have 
affected habitat for the rabbitsfoot in many large rivers rangewide. 
Periodic navigation maintenance activities (such as dredging and snag 
removal) may continue to negatively impact this species in the lower 
portions of the Ohio, Tennessee, and White Rivers, which represent 44 
percent of the viable rabbitsfoot populations. In the Tennessee River, 
a plan to deepen the navigation channel has been proposed (Hubbs 2009, 
pers. comm.). Some rabbitsfoot streams were ``straightened'' to 
decrease distances traversed by barge traffic (for example, Verdigris 
River). Hundreds of miles of many midwestern (Eel, North Fork 
Vermilion, and Embarras Rivers) and southeastern (Paint Rock and St. 
Francis Rivers and Bear Creek) streams with

[[Page 57083]]

rabbitsfoot populations were channelized decades ago to reduce the 
probability and frequency of flood events. Because mussels are 
relatively immobile, they require a stable substrate to survive and 
reproduce and are particularly susceptible to channel instability 
(Neves et al. 1997, p. 23) and alteration. Channel and bank degradation 
have led to the loss of stable substrates in numerous rivers with 
commercial navigation throughout the range of rabbitsfoot. While 
dredging and channelization have had a greater effect on rabbitsfoot, 
the Neosho mucket has been affected by these activities in the 
Verdigris River. We conclude that habitat effects due to channelization 
are an ongoing threat to the Neosho mucket and rabbitsfoot.
Sedimentation
    Excessive sediments are believed to negatively impact riverine 
mussel populations requiring clean, stable streams (Ellis 1936, pp. 39-
40; Brim Box and Mossa 1999, p. 99). Adverse effects resulting from 
sediments have been noted for many components of aquatic communities. 
Potential sediment sources within a watershed include virtually all 
activities that disturb the land surface. Most localities occupied by 
the Neosho mucket and rabbitsfoot, including viable populations, are 
currently being affected to varying degrees by sedimentation.
    Sedimentation has been implicated in the decline of mussel 
populations nationwide, and remains a threat to Neosho mucket and 
rabbitsfoot (Ellis 1936, pp. 39-40; Vannote and Minshall 1982, pp. 
4105-4106; Dennis 1984, p. 212; Brim Box and Mosa 1999, p. 99; Fraley 
and Ahlstedt 2000, pp. 193-194; Poole and Downing 2004, pp. 119-122). 
Specific biological effects include reduced feeding and respiratory 
efficiency from clogged gills, disrupted metabolic processes, reduced 
growth rates, limited burrowing activity, physical smothering, and 
disrupted host fish attraction mechanisms (Ellis 1936, pp. 39-40; 
Marking and Bills 1979, p. 210; Vannote and Minshall 1982, pp. 4105-
4106; Waters 1995, pp. 173-175; Hartfield and Hartfield 1996, p. 373). 
In addition, mussels may be indirectly affected if high turbidity 
levels significantly reduce the amount of light available for 
photosynthesis, and thus, the production of certain food items (Kanehl 
and Lyons 1992, p. 7).
    Studies tend to indicate that the primary effects of excess 
sediment levels on mussels are sublethal, with detrimental effects not 
immediately apparent (Brim Box and Mossa 1999, p. 101). The physical 
effects of sediment on mussel habitat appear to be multifold, and 
include changes in suspended and bed material load; bed sediment 
composition associated with increased sediment production and runoff in 
the watershed; channel changes in form, position, and degree of 
stability; changes in depth or the width and depth ratio that affects 
light penetration and flow regime; actively aggrading (filling) or 
degrading (scouring) channels; and changes in channel position. These 
effects to habitat may dislodge, transport downstream, or leave mussels 
stranded (Vannote and Minshall 1982, p. 4106; Kanehl and Lyons 1992, 
pp. 4-5; Brim Box and Mossa 1999, pp. 109-112). For example, many 
Kansas streams (such as Verdigris and Neosho Rivers) supporting mussels 
have become increasingly silted in over the past century, reducing 
habitat for the Neosho mucket and rabbitsfoot (Obermeyer et al. 1997a, 
pp. 113-114).
    Increased sedimentation and siltation may explain in part why 
Neosho mucket and rabbitsfoot are experiencing recruitment failure in 
some streams. Interstitial spaces in the substrate provide crucial 
habitat (shelter and nutrient uptake) for juvenile mussel survival. 
When interstitial spaces are clogged, interstitial flow rates and 
spaces are reduced (Brim Box and Mossa 1999, p. 100), and this 
decreases habitat for juvenile mussels. Furthermore, sediment may act 
as a vector for delivering contaminants, such as nutrients and 
pesticides, to streams, and juvenile mussels may ingest contaminants 
adsorbed to silt particles during normal feeding activities. Neosho 
mucket and rabbitsfoot reproductive strategies depend on clear water 
(enables fish hosts to see mussel lures) during critical reproductive 
periods.
    Agricultural activities are responsible for much of the sediment 
affecting rivers in the United States (Waters 1995, p. 170). 
Sedimentation associated with agricultural land use is cited as one of 
the primary threats to 7 of the 11 (64 percent) viable rabbitsfoot 
populations (French Creek, Tippecanoe, Paint Rock, Duck, White, Black, 
and Strawberry Rivers; Smith et al. 2009, Table 1; USACE 2011, pp. 21-
22; Indiana Department of Environmental Management (IDEM) 2001, pp. 11-
12; EPA 2001, p. 10; Brueggen 2010, pp. 1-2; MDC 2012, https://mdc.mo.gov/landwater-care/stream-and-watershed-management/; 
Environmental Protection Agency Water Quality Assessment Tool, https://ofmpub.epa.gov/tmdl_waters10/attains_nation_cy.control?p_report_type=T). In addition, numerous stream segments in the Duck, White, 
Black, Little, and Strawberry River watersheds are listed as impaired 
waters under section 303(d) of the Clean Water Act (CWA) by the 
Environmental Protection Agency (EPA) due to sedimentation associated 
with agriculture (USACE 2011, p. 21; EPA Water Quality Assessment Tool, 
https://ofmpub.epa.gov/tmdl_waters10/attains_nation_cy.control?p_report_type=T). An impaired water is a water body (i.e., stream 
reaches, lakes, water body segments) with chronic or recurring 
monitored violations of the applicable numeric or narrative water 
quality criteria. An impaired water cannot support one or more of its 
designated uses (e.g., swimming, the protection and propagation of 
aquatic life, drinking, industrial supply, etc.).
    Once a stream segment is listed as an impaired water, the State 
must complete a plan to address the issue causing the impairment; this 
plan is called a Total Maximum Daily Load (TMDL). A TMDL is a 
calculation of the maximum amount of a pollutant that a water body can 
receive and still safely meet water quality standards (WQS). Completion 
of the plan is generally all that is required to remove the stream 
segment from the EPA's section 303(d) impaired water list and does not 
mean that water quality has changed. Once the TMDL is completed, the 
stream segment may be placed on the EPA's section 305(b) list of 
impaired streams with a completed TMDL (https://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/intro.cfm). For example, some stream segments 
within the White, Barren, Little River Mountain Fork, and Wabash 
Rivers, and French Creek have completed TMDL plans and have attained 
WQS for low dissolved oxygen, pathogens, nutrients, polychlorinated 
biphenyls (PCBs), and siltation. However, some of these same stream 
segments still have not attained WQS for lead (Little River Mountain 
Fork) and mercury (Wabash River).
    Impaired streams in the Duck River watershed (approximately 483 rkm 
(300 rmi)) are losing 5 to 55 percent more soil per year than the 
natural streams (USACE 2011, pp. 21-22). Unrestricted livestock access 
occurs on many streams and potentially threatens associated mussel 
populations (Fraley and Ahlstedt 2000, pp. 193-194). Grazing may reduce 
water infiltration rates and increase runoff; trampling and vegetation 
removal increases the probability of erosion (Armour et al. 1991, pp. 
8-10; Brim Box and Mossa 1999, p. 103).
    Developed land can increase sediment loads and increase runoff 
(Wang et al. 2001, pp. 261-262). Hopkins (2009, p.

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952) found rabbitsfoot occurrence positively correlated with riparian 
areas that were 70 percent forested and averaged 15 hectares (37 acres) 
in the Upper Green River in Ohio. Rabbitsfoot begins to respond 
negatively to 0.5 percent of developed land within the riparian area 
(Hopkins 2009, pp. 948-952).
    As discussed above, specific impacts on mussels from sediments 
include reduced feeding and respiratory efficiency, disrupted metabolic 
processes, reduced growth rates, increased substrata instability, and 
the physical smothering of mussels. Increased turbidity levels due to 
siltation can be a limiting factor that impedes the ability of sight-
feeding fishes to forage. Turbidity within the rivers and streams 
during the times that the mussels attempt to attract host fishes may 
have contributed and may continue to contribute to the decline of the 
Neosho mucket and rabbitsfoot by reducing their efficiency at 
attracting the fish hosts necessary for reproduction. In addition, 
sediment can eliminate or reduce the recruitment of juvenile mussels, 
interfere with feeding activity, and act as a vector in delivering 
contaminants to streams. Because the Neosho mucket and rabbitsfoot are 
filter-feeders and may bury themselves in the substrate, they are 
exposed to these contaminants contained within suspended particles and 
deposited in bottom substrates. We conclude that biological and habitat 
effects due to sedimentation are an ongoing threat to the Neosho mucket 
and rabbitsfoot.
Chemical Contaminants
    Chemical contaminants are ubiquitous in the environment and are 
considered a major contributor to the decline of mussel species 
(Richter et al. 1997, p. 1081; Strayer et al. 2004, p. 436; Wang et al. 
2007a, p. 2029; Cope et al. 2008, p. 451). Chemicals enter the 
environment through point- and nonpoint-source discharges including 
spills, industrial and municipal effluents, and residential and 
agricultural runoff. These sources contribute organic compounds, heavy 
metals, nutrients, pesticides, and a wide variety of newly emerging 
contaminants such as pharmaceuticals to the aquatic environment. As a 
result, water and sediment quality can be degraded to the extent that 
results in adverse effects to mussel populations.
    Cope et al. (2008, p. 451) evaluated the pathways of exposure to 
environmental pollutants for all four freshwater mollusk life stages 
(free glochidia, encysted glochidia, juveniles, adults) and found that 
each life stage has both common and unique characteristics that 
contribute to observed differences in exposure and sensitivity. Almost 
nothing is known of the potential mechanisms and consequences of 
waterborne toxicants on sperm viability. In the female mollusk, the 
marsupial region of the gill is thought to be physiologically isolated 
from respiratory functions, and this isolation may provide some level 
of protection from contaminant interference with a female's ability to 
achieve fertilization or brood glochidia (Cope et al. 2008, p. 454). A 
major exception to this assertion is with chemicals that act directly 
on the neuroendocrine pathways controlling reproduction (see discussion 
below). Nutritional and ionic exchange is possible between a brooding 
female and her glochidia, providing a route for chemicals (accumulated 
or waterborne) to disrupt biochemical and physiological pathways (such 
as maternal calcium transport for construction of the glochidial 
shell). Glochidia can be exposed to waterborne contaminants for up to 
36 hours until encystment occurs between 2 and 36 hours, and then from 
fish host tissue burdens (for example, atrazine), that last from weeks 
to months and could affect transformation success of glochidia into 
juveniles (Ingersoll et al. 2007, pp. 101-104).
    Juvenile mussels typically remain burrowed beneath the sediment 
surface for 2 to 4 years. Residence beneath the sediment surface 
necessitates deposit (pedal) feeding and a reliance on interstitial 
water for dissolved oxygen (Watters 2007, p. 56). The relative 
importance of exposure of juvenile Neosho mucket and rabbitsfoot to 
contaminants in overlying surface water, interstitial water, whole 
sediment, or food has not been adequately assessed. Exposure to 
contaminants from each of these routes varies with certain periods and 
environmental conditions (Cope et al. 2008, pp. 453 and 457).
    The primary routes of exposure to contaminants for adult Neosho 
mucket and rabbitsfoot are surface water, sediment, interstitial (pore) 
water, and diet; adults can be exposed when either partially or 
completely burrowed in the substrate (Cope et al. 2008, p. 453). Adult 
mussels have the ability to detect toxicants in the water and close 
their valves to avoid exposure (Van Hassel and Farris 2007, p. 6). 
Adult mussel toxicity and relative sensitivity (exposure and uptake of 
toxicants) may be reduced at high rather than at low toxicant 
concentrations because uptake is affected by the prolonged or periodic 
toxicant avoidance responses (when the avoidance behavior of keeping 
their valves closed can no longer be sustained for physiological 
reasons (respiration and ability to feed) (Cope et al. 2008, p. 454). 
Toxicity results based on low-level exposure of adults are similar to 
estimates for glochidia and juveniles for some toxicants (for example, 
copper). The duration of any toxicant avoidance response by an adult 
mussel is likely to vary due to several variables, such as species, 
age, shell thickness and gape, properties of the toxicant, and water 
temperature. There is a lack of information on toxicant response(s) for 
Neosho mucket and rabbitsfoot, but results of tests using glochidia and 
juveniles may be valuable for protecting adults (Cope et al. 2008, p. 
454).
    Mussels are very intolerant of heavy metals (such as, lead, zinc, 
cadmium, and copper) compared to commonly tested aquatic organisms. 
Metals occur in industrial and wastewater effluents and are often a 
result of atmospheric deposition from industrial processes and 
incinerators, but also are associated with mine water runoff (for 
example, Tri-State Mining Area in southwest Missouri) and have been 
attributed to mussel declines in streams such as Shoal, Center, and 
Turkey Creeks and Spring River in the Arkansas River basin (Angelo et 
al. 2007, pp. 485-489), which are streams with historical and extant 
Neosho mucket and rabbitsfoot populations. Heavy metals can cause 
mortality and affect biological processes, for instance, disrupting 
enzyme efficiency, altering filtration rates, reducing growth, and 
changing behavior of freshwater mussels (Keller and Zam 1991, p. 543; 
Naimo 1995, pp. 351-355; Jacobson et al. 1997, p. 2390; Valenti et al. 
2005, p. 1244; Wang et al. 2007b, pp. 2039-2046; Wang et al. 2007c, pp. 
2052-2055; Wang et al. 2010, p. 2053). Mussel recruitment may be 
reduced in habitats with low but chronic heavy metal and other toxicant 
inputs (Yeager et al. 1994, p. 217; Naimo 1995, pp. 347 and 351-352; 
Ahlstedt and Tuberville 1997, p. 75). Newly transformed juveniles (age 
at 5 days) are more sensitive to acute toxicity than glochidia or older 
juveniles (age at 2 to 6 months) (Wang et al. 2010, p. 2062).
    Mercury is another heavy metal that has the potential to negatively 
affect mussel populations. Mercury has been detected throughout aquatic 
environments as a product of municipal and industrial waste and 
atmospheric deposition from coal-burning plants. One study on rainbow 
mussel (Villosa iris) concluded that glochidia were more sensitive to 
mercury than were juvenile mussels, with a median lethal

[[Page 57085]]

concentration value of 14 ug/L for glochidia and 114 ug/L for juvenile 
mussels (Valenti et al. 2005, p. 1242). The chronic toxicity is a test 
that usually measures sublethal effects (e.g., reduced growth or 
reproduction) in addition to lethality. These tests are usually longer 
in duration or conducted during some sensitive period of an organism's 
life cycle. For this species, the chronic toxicity test showed that 
juveniles exposed to mercury greater than or equal to 8 ug/L exhibited 
reduced growth (Valenti et al. 2005, p. 1245). Mercury also affects 
oxygen consumption, byssal thread production, and filtration rates 
(Naimo 1995, Jacobsen et al. 1997, and Nelson and Calabrese 1988 in 
Valenti et al. 2005, p. 1245). Effects to mussels from mercury toxicity 
may be occurring in some streams due to illegal dumping, spills, and 
permit violations. For example, acute mercury toxicity was determined 
to be the cause of extirpation of diverse mussel fauna for a 112-rkm 
(70-rmi) reach of the North Fork Holston River (Brown et al. 2005, pp. 
1455-1457). Of the 11 viable rabbitsfoot populations, 4 populations 
(French Creek, Duck River, Green River, and Ohio River) currently 
inhabit river reaches that are impaired by mercury and are listed as 
impaired waters under section 303(d) of the CWA.
    One chemical that is particularly toxic to early life stages of 
mussels is ammonia. Sources of ammonia include agricultural wastes 
(animal feedlots and nitrogenous fertilizers), municipal wastewater 
treatment plants, and industrial waste (Augspurger et al. 2007, p. 
2026) as well as precipitation and natural processes (decomposition of 
organic nitrogen) (Goudreau et al. 1993, p. 212; Hickey and Martin 
1999, p. 44; Augspurger et al. 2003, p. 2569; Newton 2003, p. 1243). 
Therefore, ammonia is considered a limiting factor for survival and 
recovery of some mussel species due to its ubiquity in aquatic 
environments and high level of toxicity, and because the highest 
concentrations typically occur in mussel microhabitats (Augspurger et 
al. 2003, p. 2574). In addition, studies have shown that ammonia 
concentrations increase with increasing temperature, pH, and low flow 
conditions (Cherry et al. 2005, p. 378; Cooper et al. 2005, p. 381; 
Wang et al. 2007, p. 2045), which may be exacerbated by the effects of 
climate change, and may cause ammonia (unionized and ionized) to become 
more problematic for juvenile mussels (Wang et al. 2007, p. 2045). 
Sublethal effects include, but may not be limited to, reduced time the 
valves are held open for respiration and feeding; impaired secretion of 
the byssal thread (used for substrate attachment), reduced ciliary 
action impairing feeding, depleted lipid, glycogen, and other 
carbohydrate stores, and altered metabolism (Goodreau et al. 1993, pp. 
216-227; Augspurger et al. 2003, pp. 2571-2574; Mummert et al. 2003, 
pp. 2548-2552).
    Polychlorinated biphenyls (PCBs) are ubiquitous contaminants in the 
environment due to their widespread use from the 1920s to 1970s as 
insulating material in electric equipment, such as transformers and 
capacitors, as well as in heat transfer fluids and in lubricants. PCBs 
have also been used in a wide range of products, such as plasticizers, 
surface coatings, inks, adhesives, flame retardants, paints, and 
carbonless duplicating paper. PCBs were still being introduced into the 
environment at many sites (such as landfills and incinerators) until 
the 1990s. The inherent stability and toxicity of PCBs have resulted in 
them being a persistent environmental problem (Safe 1994 in Lehmann et 
al. 2007, p. 356). PCBs are lipophilic (affinity to combine with fats 
or lipids), adsorb easily to soil and sediment, and are present in the 
sediment and water column in aquatic environments, making them 
available to bioaccumulate and induce negative effects in living 
organisms (Livingstone 2001 in Lehmann et al. 2007, p. 356). Studies 
have demonstrated increased PCB concentrations in native freshwater 
mussels (Ruessler et al. 2011, pp. 1, 7), marine bivalves (Krishnakumar 
et al. 1994, p. 249), and nonnative, invasive mollusks (zebra mussels 
and Asian clams) (Gossiaux et al. 1996, p. 379; Lehmann et al. 2007, p. 
363) in areas with high levels of PCBs. Oxidative stress (imbalance in 
the normal redox state of cells that causes toxic effects that damage 
all components of the cell, including proteins, lipids, and DNA) is a 
direct consequence of exposure to PCBs. Relevant changes, whether 
directly or indirectly due to oxidative stress, may occur at the organ 
and organism levels and will likely result in mussel population-wide 
effects, including reduced fecundity and chronic maladies due to PCB 
exposure (Lehmann et al. 2007, p. 363). Two of the 11 viable 
rabbitsfoot populations (18 percent) inhabit waters listed as impaired 
due to PCBs under section 303(d) of the CWA.
    Agriculture, timber harvest, and lawn management practices utilize 
nutrients and pesticides. These are two broad categories of chemical 
contaminants that have the potential to negatively impact mussel 
species. Nutrients, such as nitrogen and phosphorus, primarily occur in 
runoff from livestock farms, feedlots, heavily fertilized row crops and 
pastures (Peterjohn and Correll 1984, p. 1471), post timber management 
activities, and urban and suburban runoff, including leaking septic 
tanks, and residential lawns.
    Studies have shown that excessive nitrogen concentrations can be 
lethal to the adult freshwater pearl mussel (Margaritifera 
margaritifera) and reduce the life span and size of other mussel 
species (Bauer 1988, p. 244; Bauer 1992, p. 425). Nutrient enrichment 
can result in an increase in primary productivity, and the associated 
algae respiration depletes dissolved oxygen levels. This may be 
particularly detrimental to juvenile mussels that inhabit the 
interstitial spaces in the substrate where lower dissolved oxygen 
concentrations are more likely than on the sediment surface where 
adults tend to live (Sparks and Strayer 1998, pp. 132-133). For 
example, Galbraith et al. (2008, pp. 48-49) reported a massive die-off 
of greater than 160 rabbitsfoot specimens at a long-term monitoring 
site in the Little River, Oklahoma. While the exact cause for the die-
off is unknown, the authors speculate that the 2005 Oklahoma drought 
coupled with high water temperature and extensive blooms of filamentous 
algae may have resulted in extreme physiological stress. Over-enriched 
conditions are exacerbated by low flow conditions, such as those 
experienced during a typical summer season and that may occur with 
greater frequency and severity as a result of climate change. Three of 
the 11 viable rabbitsfoot populations (French Creek, Duck River, and 
Tippecanoe River) are listed as impaired waters under section 303(d) of 
the CWA due to nutrient enrichment.
    Elevated concentrations of pesticide frequently occur in streams 
due to residential or commercial pesticide runoff, overspray 
application to row crops, and lack of adequate riparian buffers. 
Agricultural pesticide applications often coincide with the 
reproductive and early life stages of mussels, and effects to mussels 
may be increased during a critical time period (Bringolf et al. 2007a, 
p. 2094). Recent studies tested the toxicity of glyphosate, its 
formulations, and a surfactant (MON 0818) used in several glyphosate 
formulations, to early life stages of the fatmucket (Lampsilis 
siliquoidea), a U.S. native freshwater mussel (Bringolf et al. 2007a, 
p. 2094). Studies conducted with juvenile mussels and glochidia 
determined that the surfactant (MON 0818) was the most toxic of the 
compounds tested and that L. siliquoidea glochidia were the most

[[Page 57086]]

sensitive organism tested to date (Bringolf et al. 2007a, p. 2094). 
Roundup[supreg], technical grade glyphosate isopropylamine salt, and 
isopropylamine were also acutely toxic to juveniles and glochidia 
(Bringolf et al. 2007a, p. 2097). The study of other pesticides, 
including atrazine, chlorpyrifos, and permethrin, on glochidia and 
juvenile life stages determined that chlorpyrifos was toxic to both L. 
siliquoidea glochidia and juveniles (Bringolf et al. 2007b, pp. 2101 
and 2104). The above results indicate the potential toxicity of 
commonly applied pesticides and the threat to mussel species as a 
result of the widespread use of these pesticides.
    Chemical spills have resulted in the loss of high numbers of 
mussels (Jones et al. 2001, p. 20; Brown et al. 2005, p. 1457; 
Schmerfeld 2006, pp. 12-13) and are considered a serious threat to 
mussel species. The Neosho mucket and rabbitsfoot are especially 
threatened by chemical spills because these spills can occur anywhere 
that highways with tanker trucks, industries, or mines overlap with 
their distribution.
    Other examples of the influence of point- and nonpoint-source 
pollutants on streams throughout the range of the Neosho mucket and 
rabbitsfoot include two documented mussel kills in Fish Creek (circa 
1988) as a result of manure runoff from a hog farm and a diesel spill 
(Watters 1988, p. 18). Twelve point-source discharges occur on the 
Green River (Kentucky State Nature Preserves Commission and The Nature 
Conservancy 1998, pp. 15-19). The Illinois and Little Rivers are 
subject to nonpoint-source organic runoff from poultry farming and 
municipal wastewater. Pharmaceutical chemicals used in commonly 
consumed drugs are increasingly found in surface waters. A recent 
nationwide study sampling 139 stream sites in 30 States detected the 
presence of numerous pharmaceuticals, hormones, and other organic 
wastewater contaminants downstream from urban development and livestock 
production areas (Kolpin et al. 2002, pp. 1208-1210). Another study in 
northwestern Arkansas found pharmaceuticals or other organic wastewater 
constituents at 16 of 17 sites in 7 streams surveyed in 2004 (Galloway 
et al. 2005, pp. 4-22). Toxic levels of exposure to chemicals that act 
directly on the neuroendocrine pathways controlling reproduction can 
cause premature release of viable or nonviable glochidia. For example, 
the active ingredient in many human prescription antidepressant drugs 
belonging to the class of selective serotonin reuptake inhibitors may 
exert negative reproductive effects on mussels because of the drug's 
action on serotonin and other neuroendocrine pathways (Cope et al. 
2008, p. 455). Pharmaceuticals or organic wastewater constituents are 
generally greater downstream of wastewater treatment facilities 
(Galloway et al. 2005, p. 28). Pharmaceuticals that alter mussel 
behavior and influence successful attachment of glochidia on fish hosts 
may have population-level implications for the Neosho mucket and 
rabbitsfoot.
    The information presented in this section represents some of the 
threats from chemical contaminants that have been documented both in 
the laboratory and field and demonstrates that chemical contaminants 
pose a substantial threat to Neosho mucket and rabbitsfoot. A cursory 
examination of land use trends, nonpoint- and point-source discharges, 
and the list of impaired waters under section 303(d) of the CWA 
suggests that all 11 rabbitsfoot populations currently considered 
viable may be subjected to the subtle, pervasive effects of chronic, 
low-level contamination that is ubiquitous in these watersheds. For 
example, the 8 of the 11 (73 percent) streams with viable rabbitsfoot 
populations are listed as impaired waters under section 303(d) of the 
CWA. Reasons for impairment include mercury, nutrients, organic 
enrichment and dissolved oxygen depletion, pathogens, turbidity 
(sediment), and PCBs. Potential effects from contaminant exposure may 
result in death, reduced growth, altered metabolic processes, or 
reduced reproduction. We conclude that biological and habitat effects 
of chemical contaminants are an ongoing threat contributing to the 
decline of Neosho mucket and rabbitsfoot populations.
Mining
    Gravel, coal, and metal mining are activities negatively affecting 
water quality in Neosho mucket and rabbitsfoot habitat. Instream and 
alluvial gravel mining has been implicated in the destruction of mussel 
populations (Hartfield 1993, pp. 136-138; Brim Box and Mossa 1999, pp. 
103-104). Negative effects associated with gravel mining include stream 
channel modifications (altered habitat, disrupted flow patterns, 
sediment transport), water quality modifications (increased turbidity, 
reduced light penetration, increased temperature), macroinvertebrate 
population changes (elimination), and changes in fish populations, 
resulting from adverse effects to spawning and nursery habitat and food 
web disruptions (Kanehl and Lyons 1992, pp. 4-10). Gravel mining 
activities continue to be a localized threat in several streams with 
viable rabbitsfoot populations (Ohio, Tennessee, White, Strawberry, and 
Little Rivers). In the lower Tennessee River, instream mining occurs in 
18 reaches totaling 77.1 rkm (47.9 rmi) between the Duck River 
confluence and Pickwick Landing Dam (Hubbs 2010, pers. comm.).
    Coal mining activities, resulting in heavy metal-rich drainage, and 
associated sedimentation has adversely affected many drainages with 
rabbitsfoot populations, including portions of the upper Ohio River 
system in Kentucky, Pennsylvania, and West Virginia; the lower Ohio 
River system in eastern Illinois; the Rough River drainage in western 
Kentucky; and the upper Cumberland River system in Kentucky and 
Tennessee (Ortmann 1909 in Butler 2005, p. 102; Gordon 1991, pp. 4 and 
5; Layzer and Anderson 1992 in Butler 2005, p. 102). Numerous mussel 
toxicants, such as polycyclic aromatic hydrocarbons and heavy metals 
(copper, manganese, and zinc) from coal mining contaminate sediments 
when released into streams (Ahlstedt and Tuberville 1997, p. 75). Low 
pH commonly associated with mine runoff can reduce glochidial 
attachment rates on host fish (Huebner and Pynnonen 1990, pp. 2350-
2353). Thus, acid mine runoff may have local effects on mussel 
recruitment and may lead to mortality due to improper shell development 
or erosion.
    Metal mining (lead, cadmium, and zinc) in the Tri-State Mining Area 
(15,000 square kilometers: 5,800 square miles) in Kansas, Missouri, and 
Oklahoma) has negatively affected Center and Shoal Creeks and the 
Spring River. It has been implicated in the loss of Neosho mucket and 
rabbitsfoot from portions of these streams (Obermeyer et al. 1997b, p. 
114). A study by the Kansas Department of Health and Environment 
documented a strong negative correlation between the distribution and 
abundance of native mussels, including Neosho mucket, and sediment 
concentrations of lead, zinc and cadmium in the Spring River system 
(Angelo et al. 2007, pp. 477-493). Sediment and water quality samples 
exceeded EPA 2006 threshold effect concentrations for cadmium, lead, 
and zinc at numerous sampling locations within the Tri-State Mining 
Area (Gunter 2007, pers. comm.). These physical habitat threats 
combined with poor water quality and agricultural nonpoint-source 
pollution are serious threats to all existing mussel fauna in the 
basin.
    In the St. Francis River basin, past metal mining and smelting 
(early

[[Page 57087]]

eighteenth century through the 1940s) have resulted in continuing heavy 
metal (lead, iron, nickel, copper, cobalt, zinc, cadmium, chromium) 
contamination of surface waters in the area upstream of the extant 
rabbitsfoot population. Recent and historical metals mining and 
smelting produced large volumes of contaminated wastes. Most of these 
mining wastes are stored behind poorly constructed dams and 
impoundments (Roberts 2008, pers. comm.). Wappapello Reservoir and the 
confluence with Big Creek (with habitat degradation primarily from 
mining activities) may effectively limit the distribution of the 
rabbitsfoot in the St. Francis River. We conclude that biological and 
habitat effects due to mining activities are a significant and ongoing 
threat contributing to declining Neosho mucket and rabbitsfoot 
populations.
Oil and Natural Gas Development
    Oil and natural gas resources are present in some of the watersheds 
that are known to support rabbitsfoot, including the Allegheny and 
Middle Fork Little Red Rivers and two watersheds with viable 
populations (White River and French Creek). Exploration and extraction 
of these energy resources can result in increased siltation, a changed 
hydrograph (graph showing changes in the discharge of a river over a 
period of time), and altered water quantity and quality even at 
considerable distances from the mine or well field because effects are 
carried downstream from the original source. Rabbitsfoot habitat in 
streams can be threatened by the cumulative effects of multiple mines 
and well fields (adapted from Service 2008, p. 11).
    Recently, oil and gas exploration has been able to expand in areas 
of shale due to new technologies (i.e., hydraulic fracturing and 
horizontal drilling), making access possible to oil and gas reserves in 
areas that were previously inaccessible. Extraction of these resources, 
particularly natural gas, has increased dramatically in recent years in 
Arkansas, Oklahoma, Pennsylvania, and West Virginia. Although oil and 
natural gas extraction generally occurs away from the river, extensive 
road and pipeline networks are required to construct and maintain wells 
and transport the extracted resources. These road and pipeline networks 
frequently cross or occur near tributaries, contributing sediment to 
the receiving waterway. In addition, the construction and operation of 
wells may result in the discharge of chemical contaminants and 
subsurface minerals.
    Several of the viable rabbitsfoot populations occur in active shale 
basins (areas of shale gas formations) (https://www.eia.gov/analysis/studies/worldshalegas/). In 2006, more than 3,700 permits were issued 
for oil and gas wells by the Pennsylvania Department of Environmental 
Protection, which also issued 98 citations for permit violations at 54 
wells (Hopey 2007; adapted from Service 2008, p. 13). A natural gas 
pipeline company pled guilty to three violations of the Act in 2011 for 
unauthorized take of a federally endangered mussel in Arkansas as a 
result of a large amount of sediment being transported from pipeline 
right-of-ways to tributary streams in the affected watershed 
(Department of Justice 2011, pers. comm.). Where oil and natural gas 
development occurs within the range of extant Neosho mucket and 
rabbitsfoot populations, we conclude that the resulting biological and 
habitat effects are a significant and ongoing threat contributing to 
the decline of both species.
Conservation Measures
    Nonregulatory conservation efforts that are or have addressed range 
curtailment include monitoring of the species distribution and status 
and habitat enhancement and restoration projects. Survey work 
encompassing the entire range of the Neosho mucket has been completed 
for all four States. The Service and its many State and Federal 
partners have funded projects to private landowners to enhance riparian 
habitat in many streams with Neosho mucket and rabbitsfoot populations. 
For instance, specific watershed-level projects that have benefited 
habitat for the rabbitsfoot include the critically important 
populations in the Green and Duck Rivers. Another example includes the 
State of Kentucky securing 100,000 acres of agricultural riparian lands 
in the upper Green River watershed. Other efforts have focused on 
sediment remediation work in rabbitsfoot streams. Reservoir releases 
from dams have been modified in recent years improving water quality 
and habitat conditions in many tailwaters occupied by rabbitsfoot. Flow 
improvements below dams have enabled partners to attempt the 
reintroduction of listed species such as the rabbitsfoot. TVA has 
modified the Tims Ford Dam operations on the Elk River that will add 30 
river miles of good habitat upstream from Fayetteville and in the dam 
tailwaters. TVA has committed to water quality and biological 
monitoring for a period of 10 years.
    Methods have been devised and implemented for the propagation of 
Neosho mucket and rabbitsfoot. The States of Kansas and Missouri have 
released thousands of juvenile Neosho mucket individuals in the Fall, 
Verdigris, and Spring Rivers. The State of Kansas reintroduced Neosho 
mucket at two sites in the Cottonwood River. The State of Alabama 
reintroduced rabbitsfoot in Limestone Creek. Similar efforts to augment 
rabbitsfoot populations in Kentucky are under way.
    The Service is processing Safe Harbor Agreements and Candidate 
Conservation Agreements with Assurances with private landowners to 
conserve aquatic species. Rabbitsfoot is one of the species included in 
two programmatic Safe Harbor Agreements (SHA) in Arkansas. 
Implementation of the upper Little Red River SHA began in 2007, and 
approximately 12,000 acres have been enrolled to date. This SHA is 
currently undergoing permit amendment to add rabbitsfoot, but the SHA 
already covers another mussel (speckled pocketbook) and conservation 
measures currently being implemented on enrolled lands will benefit 
rabbitsfoot. A similar programmatic SHA is currently in the final 
stages of development and awaiting permit approval from the Service in 
the Saline, Ouachita, and Caddo Rivers (headwaters) watershed.
Summary of Factor A
    The decline of mussels in the eastern United States is primarily 
the result of long-lasting direct and secondary effects of habitat 
alterations such as impoundments, channelization, sedimentation, 
chemical contaminants, oil and gas development, and mining, and it is 
reasonable to conclude that the changes in the river basins 
historically and currently occupied by the species are the cause of 
population-level (river basin) effects. Historical population losses 
due to impoundments have probably contributed more to the decline and 
range reductions of the Neosho mucket and rabbitsfoot than any other 
single factor. Seven of the 11 (64 percent) viable rabbitsfoot 
populations (Ohio, Green, Tippecanoe, Tennessee, Duck, White, and 
Little Rivers) occur downstream of main stem impoundments that make 
these populations more susceptible to altered habitat quality and 
quantity associated with the impoundment and dam operation, which may 
be exacerbated during stochastic events such as droughts and floods. 
Sedimentation resulting from a variety of sources such as 
channelization, agricultural and silvicultural practices, and 
construction

[[Page 57088]]

activities has degraded Neosho mucket and rabbitsfoot habitat and 
altered biological processes essential to their survival. For example, 
sedimentation associated with agricultural land use is cited as one of 
the primary threats to 7 of the 11 (64 percent) streams with viable 
rabbitsfoot populations.
    Land use conversion, particularly urbanization that increases 
impervious surfaces in watersheds (impervious surface increases flood 
intensity and duration), channelization, and instream gravel and sand 
mining alter natural hydrology and stream geomorphology characteristics 
that also degrade mussel habitat in streams that support the Neosho 
mucket and rabbitsfoot. Contaminants associated with industrial and 
municipal effluents, agricultural practices, and mining degrade water 
and sediment quality leading to environmental conditions that have 
lethal and sublethal effects to Neosho mucket and rabbitsfoot, 
particularly the highly sensitive early life stages. Eight of the 11 
(73 percent) streams with viable rabbitsfoot populations are listed as 
impaired waters under section 303(d) of the CWA, which means that the 
rabbitsfoot may be subjected to the subtle, pervasive effects of 
chronic, low-level contamination that is ubiquitous in these 
watersheds. Chronic contamination can affect the mussels in a variety 
of ways including sublethal effects (such as suppressed immune systems 
and effects to reproduction and fecundity from neuroendocrine 
disrupters) and lethal effects (such as sediment smothers and 
disruption of other metabolic processes).
    In summary, we have determined that impoundments, channelization, 
sedimentation, chemical contaminants, mining, and oil and natural gas 
development are ongoing threats to the Neosho mucket and rabbitsfoot 
and their habitat that are expected to continue into the future. 
Although efforts have been made to restore habitat in some areas, these 
threats are still ongoing, as evidenced by population declines and 
range reduction.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The Neosho mucket was valuable in the pearl button industry (1800s 
to early 1940s), and historical episodes of overharvest in the Neosho 
River may have contributed to its decline (Obermeyer et al. 1997b, p. 
115). The rabbitsfoot was never a valuable shell for the commercial 
pearl button industry (Meek and Clark 1912, p. 15; Murray and Leonard 
1962, p. 65), nor the cultured pearl industry (Williams and Schuster 
1989, p. 23), and hence these activities were probably not significant 
factors in its decline. However, it was noted occasionally in 
commercial harvests as evidenced from mussel cull piles (Isely 1924; 
Parmalee et al. 1980, p. 101). Currently, Neosho mucket and rabbitsfoot 
are not commercially valuable species but may be increasingly sought by 
collectors as they become rarer. Although scientific collecting is not 
thought to represent a significant threat, unregulated collecting could 
adversely affect localized Neosho mucket and rabbitsfoot populations.
    Commercial mussel harvest is illegal in some States (for example, 
Indiana and Ohio), but regulated in others (for example, Arkansas, 
Alabama, Kentucky, and Tennessee). These species may be inadvertently 
harvested by inexperienced commercial harvesters unfamiliar with 
species identification. Although illegal harvest of protected mussel 
beds occurs (Watters and Dunn 1995, pp. 225 and 247-250), commercial 
harvest is not known to have a significant effect on the Neosho mucket 
and rabbitsfoot.
Conservation Measures
    We are not aware of any nonregulatory actions that are being 
conducted to ameliorate overutilization for commercial, recreational, 
scientific, or educational purposes at this time.
Summary of Factor B
    Though it is possible that the intensity of inadvertent or illegal 
harvest may increase in the future, we have no evidence that this 
stressor is currently increasing in severity. On the basis of this 
analysis, we find that overutilization for commercial, recreational, 
scientific, or educational purposes is not a current threat to the 
Neosho mucket or rabbitsfoot in any portion of their range at this time 
nor is likely to become so in the future.

Factor C. Disease or Predation

    Little is known about diseases in freshwater mussels (Grizzle and 
Brunner 2007, p. 6). However, mussel die-offs have been documented in 
streams inhabited by rabbitsfoot (Neves 1986, pp. 8-11), and some 
researchers believe that disease may be a factor contributing to the 
die-offs (Buchanan 1986, p. 53; Neves 1986, p. 11). Mussel parasites 
include water mites, trematodes, oligochaetes, leeches, copepods, 
bacteria, and protozoa (Grizzle and Brunner 2007, p. 4). Generally, 
parasites are not suspected of being a major limiting factor in the 
species' survival (Oesch 1984, p. 6). However, mite and trematode 
burdens can affect reproductive output and physiological condition, 
respectively, in mussels (Gangloff et al. 2008, pp. 28-30). Stressors 
that reduce fitness may make mussels more susceptible to parasites 
(Butler 2007, p. 90). Furthermore, nonnative mussels may carry diseases 
and parasites that are potentially devastating to the native mussel 
fauna on an individual or population-level basis (river basin), 
including Neosho mucket and rabbitsfoot (Strayer 1999b, p. 88). 
However, while individual mussels or beds of mussels historically or 
currently may have been affected by disease or parasites, we have no 
evidence that the severity of disease or parasite infestations impact 
either mussel on a population level (river basin).
    The muskrat (Ondatra zibethicus) is cited as the most prevalent 
mussel predator (Kunz 1898, p. 328; Convey et al. 1989, pp. 654-655; 
Hanson et al. 1989, pp. 15-16). Muskrat predation may limit the 
recovery potential of endangered or threatened mussels or contribute to 
local extirpations of previously stressed populations, according to 
Neves and Odom (1989, p. 940), who consider it, however, primarily a 
seasonal or localized threat. Galbraith et al. (2008, p. 49) 
hypothesized that predation may have exacerbated rabbitsfoot mortality 
in the Little River, Oklahoma, during the 2005 drought. Harris et al. 
(2007, p. 31) reported numerous dead rabbitsfoot from muskrat middens 
(mound or deposit containing shells) in the Spring River, Arkansas. 
Other mammals (for example, raccoon, mink, otter, hogs, and rats), 
turtles, and aquatic birds also occasionally feed on mussels (Kunz 
1898, p. 328; Neck 1986, pp. 64-65). Recently, predation of Neosho 
mucket by reintroduced otters has been documented in a mussel bed also 
supporting rabbitsfoot in the Spring River, Kansas (Barnhart 2003, pp. 
16-17), and likely occurs elsewhere. Muskrat predation has been 
documented for Neosho mucket and rabbitsfoot, but the overall threat is 
generally considered insignificant.
    Some species of fish feed on mussels (for example, common carp 
(Cyprinus carpio), freshwater drum (Aplodinotus grunniens), and redear 
sunfish (Lepomis microlophus)) and potentially on young Neosho mucket 
and rabbitsfoot. Various invertebrates, such as flatworms, hydra, 
nonbiting midge larvae, dragonfly larvae, and crayfish, feed on 
juvenile mussels (Zimmerman et al. 2003, p. 28). Although predation by 
naturally occurring predators is a normal aspect of the population 
dynamics of a healthy mussel population, predation may

[[Page 57089]]

amplify declines in small populations of this species. In addition, the 
potential now exists for black carp (Mylopharyngodon piceus), a 
mollusk-eating Asian fish recently introduced into the waters of the 
United States (Strayer 1999b, p. 89), to eventually disperse throughout 
the range of the Neosho mucket and rabbitsfoot. However, we have no 
evidence that the severity of predation has reached levels where 
populations (river basin) of either mussel have been historically or 
recently impacted or should be impacted in the future based on current 
information.
    The life cycle of freshwater mussels is intimately related to that 
of the freshwater fish they use as hosts for their parasitic glochidia. 
For this reason, diseases that affect populations of freshwater fishes 
also pose a significant threat to mussels in general. Viral hemorrhagic 
septicemia (VHS) disease has been confirmed from much of the Great 
Lakes and St. Lawrence River system. If the VHS virus successfully 
migrates out of Clearfork Reservoir or the Great Lakes and into the 
Ohio and Mississippi River basins, it could spread rapidly and cause 
fish kills throughout the river basins. Few Neosho mucket and 
rabbitsfoot populations are currently recruiting at sustainable levels, 
and fish kills, particularly if VHS infects suitable fish hosts, could 
further reduce glochidia encounters with fish hosts and exacerbate 
mussel recruitment reductions. However, we have no evidence that fish 
kills affecting potential fish hosts of these two mussel species have 
had population effects historically or recently.
Conservation Measures
    Nonregulatory conservation measures implemented include control of 
the Asian carp and black carp. Both species are listed under the 
Injurious Wildlife Provision of the Lacey Act, which prohibits the 
import, export, and transport between States. Numerous States within 
the range of Neosho mucket and rabbitsfoot are engaging in efforts 
(such as, eradication) to minimize the effects of Asian carp on native 
fishery resources.
Summary of Factor C
    Disease in mussels is poorly known and not currently considered a 
threat rising to a level such that it would have an effect on the 
Neosho mucket, nor the rabbitsfoot, as a whole. Studies indicate that, 
in some localized areas, disease and predation may have negative 
effects on mussel populations. Though it is possible that the intensity 
of disease or predation may increase in the future, we have no evidence 
that this stressor is currently increasing in severity.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    The objective of the Federal Water Pollution Control Act, commonly 
referred to as the Clean Water Act (CWA) (33 U.S.C. 1251 et seq.), is 
to restore and maintain the chemical, physical, and biological 
integrity of the nation's waters by preventing point and nonpoint 
pollution sources. The CWA has a stated goal that ``. . . wherever 
attainable, an interim goal of water quality which provides for the 
protection and propagation of fish, shellfish, and wildlife and 
provides for recreation in and on the water be achieved by July 1, 
1983.'' States are responsible for setting and implementing water 
quality standards that align with the requirements of the CWA. Overall, 
implementation of the CWA could benefit both mussel species through the 
point and nonpoint programs.
    Nonpoint source (NPS) pollution comes from many diverse sources, 
unlike pollution from industrial and sewage treatment plants. NPS 
pollution is caused by rainfall or snowmelt moving over and through the 
ground. As the runoff moves, it transports natural and human-made 
pollutants. While some pollutants may be ``deposited,'' some may remain 
in suspension (dissolved) as they are transported through various 
waterbodies. States report that nonpoint source pollution is the 
leading remaining cause of water quality problems. The effects of 
nonpoint-source pollutants on specific waters vary and may not always 
be fully assessed. However, these pollutants have harmful effects on 
fisheries and wildlife (https://www.epa.gov/owow_keep/NPS/whatis.html).
    Sources of NPS pollution within the watersheds occupied by both 
mussels include timber clearcutting, clearing of riparian vegetation, 
urbanization, road construction, and other practices that allow bare 
earth to enter streams (The Nature Conservancy 2004, p. 13). Numerous 
stream segments in the Duck, White, Black, Little, and Strawberry River 
watersheds are listed as impaired waters under section 303(d) of the 
CWA by EPA due to sedimentation associated with agriculture (USACE 
2011, p. 21; EPA Water Quality Assessment Tool, https://ofmpub.epa.gov/tmdl_waters10/attains_nation_cy.control?p_report_type=T). For 
example, impaired streams in the Duck River watershed (483 rkm (300 
rmi)) are losing 5 to 55 percent more soil per year than streams not 
labeled as impaired (USACE 2011, pp. 21-22). Currently, the CWA may not 
adequately protect Neosho mucket and rabbitsfoot habitat from NPS 
pollution. The Service has no information concerning the implementation 
of the CWA regarding NPS pollution specific to protection of both 
mussels. However, insufficient implementation could become a threat to 
both mussel species if they continue to decline in numbers or if new 
information becomes available.
    Point-source discharges within the range of the Neosho mucket and 
rabbitsfoot have been reduced since the enactment of the CWA. Despite 
some reductions in point-source discharges, adequate protection may not 
be provided by the CWA for filter-feeding organisms that can be 
affected by extremely low levels of contaminants (see Chemical 
Contaminants discussion under Factor A). The Neosho mucket and 
rabbitsfoot continue to decline due to the effects of habitat 
destruction, poor water quality, contaminants, and other factors. Eight 
of the 11 (73 percent) streams with viable rabbitsfoot populations are 
listed as impaired waters under section 303(d) of the CWA. Reasons for 
impairment include mercury, nutrients, organic enrichment, dissolved 
oxygen depletion, pathogens, turbidity (sediment), and PCBs. In 
addition, numerous tributaries within watersheds supporting viable 
Neosho mucket and rabbitsfoot populations also are listed as impaired 
waters under section 303(d) of the CWA, which means that both species 
may be subjected to greater, albeit subtle, pervasive effects of 
chronic, low-level contamination that is ubiquitous in these 
watersheds. However, we are aware of no specific information about the 
sensitivity of the Neosho mucket and rabbitsfoot to common point-source 
pollutants like industrial and municipal pollutants and very little 
information on other freshwater mussels. Because little information is 
available about water quality parameters necessary to fully protect 
freshwater mussels, such as the Neosho mucket and rabbitsfoot, it is 
difficult to determine whether the CWA is adequately addressing the 
threats to these species. However, given that a goal of the CWA is to 
establish water quality standards that protect shellfish and given that 
documented declines of these mussel species still continue due to poor 
water quality and other factors, we take a conservative approach in 
favor of the species and conclude that the CWA has been insufficient to 
reduce or remove the threats to the Neosho mucket and rabbitsfoot.

[[Page 57090]]

Summary of Factor D
    In summary, the CWA has a stated goal to establish water quality 
standards that protect aquatic species, including the Neosho mucket and 
rabbitsfoot. However, the CWA has generally been insufficient at 
protecting mussels, and adequate water quality criteria that are 
protective of all life stages, particularly glochidia and juveniles, 
may not have been established. Little information is known about 
specific sensitivities of mussels to various pollutants, but both 
species continue to decline due to the effects of habitat destruction, 
poor water quality, contaminants, and other factors.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Population Fragmentation and Isolation
    Population fragmentation and isolation prohibit the natural 
interchange of genetic material between populations. Most of the 
remaining Neosho mucket and rabbitsfoot populations are small and 
geographically isolated, and, thus, are susceptible to genetic drift, 
inbreeding depression, and stochastic changes to the environment, such 
as toxic chemical spills (Smith 1990, pp. 311-321; Watters and Dunn 
1995, pp. 257-258; Avise and Hamrick 1996, pp. 463-466). For example, 
the Spring River (White River basin) and Muddy Creek (Ohio River basin) 
rabbitsfoot populations are the only small populations not isolated 
from a viable population. Three marginal populations (Alleghany River 
and LeBoeuf and Conneauttee Creeks), considered metapopulations with 
French Creek, also are not isolated from a viable rabbitsfoot 
population (French Creek). However, 41 of 51 extant rabbitsfoot 
populations (80 percent) are isolated from other extant populations, 
excluding those discussed above and the Strawberry, Tennessee, and Ohio 
Rivers, which are viable populations that are not isolated from another 
viable population (Black River) or each other (lower Tennessee and Ohio 
Rivers).
    Inbreeding depression can result in early mortality, decreased 
fertility, smaller body size, loss of vigor, reduced fitness, and 
various chromosome abnormalities (Smith 1990, pp. 311-321). A species' 
vulnerability to extinction is increased when they are patchily 
distributed due to habitat loss and degradation (Noss and Cooperrider 
1994, pp. 58-62; Thomas 1994, p. 373). Although changes in the 
environment may cause populations to fluctuate naturally, small and 
low-density populations are more likely to fluctuate below a minimum 
viable population size (the minimum or threshold number of individuals 
needed in a population to persist in a viable state for a given 
interval) (Shaffer 1981, p. 131; Shaffer and Samson 1985, pp. 148-150; 
Gilpin and Soul[eacute] 1986, pp. 25-33). Furthermore, this level of 
isolation makes natural repopulation of any extirpated population 
unlikely without human intervention. Population isolation prohibits the 
natural interchange of genetic material between populations, and small 
population size reduces the reservoir of genetic diversity within 
populations, which can lead to inbreeding depression (Avise and 
Hambrick 1996, p. 461).
    Neosho mucket and rabbitsfoot were once widespread throughout their 
respective ranges with few natural barriers to prevent migration (via 
fish host species) among suitable habitats. However, construction of 
dams extirpated many Neosho mucket and rabbitsfoot populations and 
isolated others. Recruitment reduction or failure is a potential 
problem for many small Neosho mucket and rabbitsfoot populations 
rangewide, a potential condition exacerbated by their reduced range, 
increasingly small populations, and increasingly isolated populations. 
If these trends continue, further significant declines in total 
population size and subsequent reduction in long-term survivability may 
be observed in the future.
    The likelihood is high that some rabbitsfoot and Neosho mucket 
populations are below the effective population size (EPS--the number of 
individuals in a population who contribute offspring to the next 
generation), based on restricted distribution and populations only 
represented by a few individuals, and achieving the EPS is necessary 
for a population to adapt to environmental change and maintain long-
term viability. Isolated populations eventually are extirpated when 
population size drops below the EPS or threshold level of 
sustainability (Soul[eacute] 1980, pp. 162-164). Evidence of 
recruitment in many populations of these two species is scant, making 
recruitment reduction or outright failure suspect. These populations 
may be experiencing the bottleneck effect of not attaining the EPS. 
Small, isolated, below the EPS-threshold populations of short-lived 
species (most fish hosts) theoretically die out within a decade or so, 
while below-threshold populations of long-lived species, such as the 
Neosho mucket and rabbitsfoot, might take decades to die out even given 
years of total recruitment failure. Without genetic interchange, small, 
isolated populations could be slowly expiring, a phenomenon termed the 
extinction debt (Tilman et al. 1994, pp. 65-66). Even given the absence 
of existing or new anthropogenic threats, disjunct populations may be 
lost as a result of current below-threshold effective population size. 
Additionally, evidence indicates that general habitat degradation 
continues to decrease habitat patch size, further contributing to the 
decline of Neosho mucket and rabbitsfoot populations.
    We find that fragmentation and isolation of small remaining 
populations of the Neosho mucket and rabbitsfoot are current and 
ongoing threats to both species throughout all of their ranges and will 
continue into the future. Further, stochastic events may play a 
magnified role in population extirpation when small, isolated 
populations are involved.
Invasive Nonindigenous Species
    Various invasive or nonnative species of aquatic organisms are 
firmly established in the range of the Neosho mucket and rabbitsfoot. 
The nonnative, invasive species that poses the most significant threat 
is the zebra mussel, Dreissena polymorpha, introduced from Europe. Its 
invasion poses a threat to mussel faunas in many regions, and species 
extinctions are expected as a result of its continued spread in the 
eastern United States (Ricciardi et al. 1998, p. 613). Strayer (1999b, 
pp. 75-80) reviewed in detail the mechanisms by which zebra mussels 
affect native mussels. Zebra mussels attach in large numbers to the 
shells of live native mussels and are implicated in the loss of entire 
native mussel beds. Fouling effects include impeding locomotion (both 
laterally and vertically), interfering with normal valve movements, 
deforming valve margins, and locally depleting food resources and 
increasing waste products. Heavy infestations of zebra mussels on 
native mussels may overly stress the animals by reducing their energy 
stores. They may also reduce food concentrations to levels too low to 
support reproduction, or even survival in extreme cases. Zebra mussels 
also may affect Neosho mucket and rabbitsfoot through filtering and 
removing their sperm and possibly glochidia from the water column, thus 
reducing reproductive potential. Habitat for native mussels also may be 
degraded by large deposits of zebra mussel pseudofeces (undigested 
waste material passed out of the incurrent siphon) (Vaughan 1997, p. 
11).
    Overlapping much of the current range of the Neosho mucket and 
rabbitsfoot, zebra mussels have been

[[Page 57091]]

detected or are established in Neosho mucket (Neosho and Verdigris 
Rivers) and rabbitsfoot streams (Ohio, Allegheny, Green, Tennessee, 
White, and Verdigris Rivers, and French and Bear Creeks). Zebra mussel 
populations appear to be maintained primarily in streams with barge 
navigation (Stoeckel et al. 2003, p. 334). As zebra mussels may 
maintain high densities in big rivers, large tributaries, and below 
infested reservoirs, rabbitsfoot populations in these affected areas 
have the potential to be significantly affected. In addition, there is 
long-term potential for zebra mussel invasions into other systems that 
currently harbor Neosho mucket and rabbitsfoot populations. However, 
evidence is mounting in some northern streams where there is no barge 
navigation (French Creek and Tippecanoe River) and southern ones with 
barge traffic (Tennessee River) that the zebra mussel threat to native 
mussels may be minimal because native freshwater mussel populations are 
able to survive when zebra mussel abundance is low (Butler 2005, p.116; 
Fisher 2009, pers. comm.).
    The Asian clam (Corbicula fluminea) has spread throughout the range 
of Neosho mucket and rabbitsfoot since its introduction in the early 
twentieth century. It competes with native mussels, particularly 
juveniles, for resources such as food, nutrients, and space (Neves and 
Widlak 1987, p. 6; Leff et al. 1990, p. 414), and may ingest sperm, 
glochidia, and newly metamorphosed juveniles of native mussels (Strayer 
1999b, p. 82; Yeager et al. 2000, p. 255). Periodic die-offs of Asian 
clams may produce enough ammonia and consume enough dissolved oxygen to 
kill native mussels (Strayer 1999b, p. 82). Yeager et al. (2000, pp. 
257-258) determined that high densities of Asian clams negatively 
affect the survival and growth of newly metamorphosed juvenile mussels 
and thus reduced recruitment. Dense Asian clam populations actively 
disturb sediments that may reduce habitat for juveniles of native 
mussels (Strayer 1999b, p. 82).
    Asian clam densities vary widely in the absence of native mussels 
or in patches with sparse mussel concentrations, but Asian clam density 
is never high in dense mussel beds, indicating that the clam is unable 
to successfully invade small-scale habitat patches with high unionid 
biomass (Vaughn and Spooner 2006, pp. 334-335). The invading clam, 
therefore, appears to preferentially invade sites where mussels are 
already in decline (Strayer 1999b, pp. 82-83; Vaughn and Spooner 2006, 
pp. 332-336) and does not appear to be a causative factor in the 
decline of mussels in dense beds. However, an Asian clam population 
that thrives in previously stressed, sparse mussel populations might 
exacerbate mussel decline through competition and by impeding mussel 
population expansion (Vaughn and Spooner 2006, pp. 335-336).
    A molluscivore (mollusk eater), the introduced black carp 
(Mylopharyngodon piceus), is a potential threat to Neosho mucket and 
rabbitsfoot (Strayer 1999b, p. 89). It has been proposed for widespread 
use by aquaculturists to control snails, the intermediate host of a 
trematode (flatworm) parasite affecting catfish in ponds in the 
southeast and lower midwest. They are known to feed on various 
mollusks, including mussels and snails, in China. They are the largest 
of the Asiatic carp species, reaching more than 1.2 meters (4 feet) in 
length (Nico and Williams 1996, p. 6). Foraging rates for a 4-year-old 
fish average 1.4-1.8 kg (3 or 4 pounds) a day, indicating that a single 
individual could consume 9,072 kilograms (10 tons) of native mollusks 
during its lifetime (MICRA 2005, p. 1). In 1994, 30 black carp escaped 
from an aquaculture facility in Missouri during a flood. The escape of 
nonsterile black carp is considered imminent by conservation biologists 
(Butler 2007, pp. 95-96). The black carp was officially added to the 
Federal list of injurious wildlife species on October 18, 2007 (72 FR 
59019).
    The round goby (Neogobius melanostomus) is another nonnative, 
invasive fish species released in the 1980s that is well established 
and likely to spread through the Mississippi River system (Strayer 
1999b, pp. 87-88). This species is an aggressive competitor of similar-
sized benthic fishes (sculpins and darters), as well as a voracious 
carnivore, despite its size (less than 25.4 centimeters (10 inches) in 
length), preying on a variety of foods, including small mussels and 
fishes that could serve as glochidial hosts (Strayer 1999b, p. 88; 
Janssen and Jude 2001, p. 325). Round gobies may, therefore, pose a 
threat to Neosho mucket and rabbitsfoot reproduction.
    The golden alga (Prymnesium parvum) is an invasive marine or 
estuarine algae that likely originated in Europe (Barkoh and Fries 
2010, p. 2). Golden alga is found throughout 20 States in the United 
States. Algae blooms and fish kills have been reported in the following 
States that overlap the range of Neosho mucket and rabbitsfoot: 
Arkansas, Oklahoma, Alabama, Louisiana, Mississippi, Georgia, West 
Virginia, and Kentucky (Hambright 2012, p. 33). Golden alga blooms have 
been associated with mine and gas outfalls, specifically high chlorides 
(Sextone 2012, p. 1). Golden alga can give off toxins, when inorganic 
nitrogen and phosphorous are scarce, that are lethal to gill-breathing 
organisms, such as mussels and fishes. The toxins also can kill other 
invertebrates, planktonic algae, and bacteria (Barkoh and Fries 2010, 
p. 1). A golden alga bloom can be detrimental to Neosho mucket and 
rabbitsfoot by directly killing individuals and fish hosts and 
destroying their food base. Nonnative, invasive species, such as those 
described above, are an ongoing threat to the Neosho mucket and 
rabbitsfoot. This threat is likely to increase as these and potentially 
other invasive species expand their occupancy within the ranges of the 
Neosho mucket and rabbitsfoot through displacement, recruitment 
interference, and direct predation of the mussels and their fish hosts.
Temperature
    Natural temperature regimes can be altered by impoundments, 
tailwater releases from dams, industrial and municipal effluents, and 
changes in riparian habitat. Low temperatures can significantly delay 
or prevent metamorphosis in mussels (Watters and O'Dee 1999, pp. 454-
455). Cold water effluent below dams may negatively impact populations; 
rabbitsfoot were less abundant and in poor condition below a cold water 
outflow on the Little River, compared to two other sites upstream 
(Galbraith and Vaughn 2011, p. 198). Low water temperatures caused by 
dam releases also may disrupt seasonal patterns in reproduction on the 
Little River (Galbraith and Vaughn 2009, pp. 43-44).
    Exact critical thermal limits for survival and normal functioning 
of many freshwater mussel species are unknown. However, high 
temperatures can reduce dissolved oxygen concentrations in the water, 
which slows growth, reduces glycogen stores, impairs respiration, and 
may inhibit reproduction (Fuller 1974, pp. 240-241). Thermally 
sensitive species decrease their water filtering and oxygen consumption 
at higher temperatures (Spooner and Vaughn 2008, p. 314). Although we 
do not have physiological data on rabbitsfoot and Neosho mucket, 
closely related species, the plain pocketbook (Lampsilis cardium) and 
the pimpleback (Quadrula pustulosa), are thermally sensitive (Spooner 
and Vaughn 2008, p. 313). Water temperature increases have been 
documented to shorten the period of

[[Page 57092]]

glochidial encystment, reduce righting speed (various reflexes that 
tend to bring the body into normal position in space and resist forces 
acting to displace it out of normal position), and slow burrowing and 
movement responses (Bartsch et al. 2000, p. 237; Watters et al. 2001, 
p. 546; Schwalb and Pusch 2007, pp. 264-265). Several studies have 
documented the influence of temperature on the timing aspects of mussel 
reproduction (Gray et al. 2002, p. 156; Allen et al. 2007, p. 85; 
Steingraeber et al. 2007, pp. 303-309). Peak glochidial releases are 
associated with water temperature thresholds that can be thermal 
minimums or maximums, depending on the species (Watters and O'Dee 2000, 
p. 136).
    Alterations in temperature regimes in streams, such as those 
described above, are an ongoing threat to the Neosho mucket and 
rabbitsfoot. This threat is likely to continue and increase in the 
future due to additional navigation or water supply projects and as 
land use conversion to urban uses increases within the entire ranges of 
the Neosho mucket and rabbitsfoot.
Climate Change
    Our analyses under the Act include consideration of ongoing and 
projected changes in climate. The terms ``climate'' and ``climate 
change'' are defined by the Intergovernmental Panel on Climate Change 
(IPCC). ``Climate'' refers to the mean and variability of different 
types of weather conditions over time, with 30 years being a typical 
period for such measurements, although shorter or longer periods also 
may be used (IPCC 2007, p. 78). The term ``climate change'' thus refers 
to a change in the mean or variability of one or more measures of 
climate (e.g., temperature or precipitation) that persists for an 
extended period, typically decades or longer, whether the change is due 
to natural variability, human activity, or both (IPCC 2007, p. 78). 
Various types of changes in climate can have direct or indirect effects 
on species. These effects may be positive, neutral, or negative and 
they may change over time, depending on the species and other relevant 
considerations, such as the effects of interactions of climate with 
other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-
19). In our analyses, we use our expert judgment to weigh relevant 
information, including uncertainty, in our consideration of various 
aspects of climate change.
    Projected changes in climate and related effects can vary 
substantially across and within different regions of the world (e.g., 
IPCC 2007a, pp. 8-12). Thus, although global climate projections are 
informative and in some cases are the only or the best scientific 
information available, to the extent possible we use ``downscaled'' 
climate projections which provide higher resolution information that is 
more relevant to the spatial scales used to assess effects to a given 
species (see Glick et al. 2011, pp. 58-61 for a discussion of 
downscaling). With regard to our analysis for the Neosho mucket and the 
rabbitsfoot, downscaled projections of climate change are available, 
but projecting precise effects on these two species from downscaled 
models is difficult because of the large geographic areas inhabited by 
both species. However, projections for the change in annual air 
temperature by the year 2080 for the Neosho mucket ranges between an 
increase of 7 to 8 degrees Fahrenheit ([deg]F) and for the rabbitsfoot, 
an increase of 4.5 to 8[emsp14][deg]F in annual air temperature (Maura 
et al. 2007, as displayed on https://www.climatewizard.org/# 2012).
    Mussels can be placed into thermal guilds, thermally sensitive and 
thermally tolerant species, according to their response to warm summer 
water temperatures greater than 35 [deg]C (95[emsp14][deg]F) (Spooner 
and Vaughn 2008, p. 313). Although we do not have physiological data on 
rabbitsfoot and Neosho mucket, closely related species, Lampsilis 
cardium and Quadrula pustulosa, are thermally sensitive (Spooner and 
Vaughn 2008, p. 313). Data for the Kiamichi River in Oklahoma suggests 
that, over the past 17 years as water and air temperatures have 
increased, mussel beds once dominated by thermally sensitive species 
are now dominated by thermally tolerant species (Galbraith et al. 2010, 
p. 1179; Spooner and Vaughn 2008, p. 316). As temperature increases due 
to climate change throughout the range of Neosho mucket and 
rabbitsfoot, both species may experience population declines as warmer 
rivers are more suitable for thermally tolerant species.
    Ficke et al. (2005, pp. 67-69; 2007, pp. 603-605) described the 
general potential effects of climate change on freshwater fish 
populations worldwide. Overall, the distribution of fish species is 
expected to change, including range shifts and local extirpations. 
Because freshwater mussels are entirely dependent upon a fish host for 
successful reproduction and dispersal, any changes in local fish 
populations would also affect freshwater mussel populations. Therefore, 
mussel populations will reflect local extirpations or decreases in 
abundance of fish species.
Conservation Measures
    Nonregulatory conservation measures that address these threats 
include implementing artificial propagation programs (see Summary of 
Factor A). The Interior Highlands Mollusk Conservation Council, Ohio 
River Ecosystem Team--Mollusk Subcommittee and similar working groups 
targeting mussel conservation efforts, has been created and includes 
the Service, State and Federal agencies, nongovernmental organizations, 
academia, and Tribes.
Summary of Factor E
    A variety of natural and manmade factors threatens the continued 
existence of Neosho mucket and rabbitsfoot. Forty-one of the 51 (80 
percent) extant rabbitsfoot populations are isolated from viable 
populations. A lack of recruitment and genetic isolation pose a threat 
to the continued existence of these species. Invasive, nonindigenous 
species, such as zebra mussel, black carp, and Asian clam, have 
potentially adversely affected populations of the Neosho mucket and 
rabbitsfoot and their fish hosts, and these effects are expected to 
persist into the future. Evidence exists that the interaction of 
climate change and water management negatively impacts mussels 
(Galbraith et al. 2010, pp. 1179-1180). Drought combined with water 
management practices has led to high mortality in thermally sensitive 
species (Galbraith et al. 2010, pp. 1180-1181). Based on the best 
available information, we are unable to predict the timing and scope of 
any changes to these mussel species that may occur as a result of 
climate change effects, particularly when combined with effects from 
water management practices.

Cumulative Effects of Threats

    The life-history traits and habitat requirements of the Neosho 
mucket and rabbitsfoot, and other freshwater mussels in general, make 
them extremely susceptible to environmental change. Unlike other 
aquatic organisms (e.g., aquatic insects and fish), mussels have 
limited refugia from stream disturbances (e.g., droughts, 
sedimentation, chemical contaminants). Mechanisms leading to the 
decline of Neosho mucket and rabbitsfoot, as discussed above, range 
from local (e.g., riparian clearing, chemical contaminants, etc.) to 
regional influences (e.g., altered flow regimes, channelization, etc.), 
to global climate change. The synergistic (interaction of two or more 
components) effects of threats are often complex in aquatic

[[Page 57093]]

environments, making it difficult to predict changes in mussel and fish 
host(s) distribution, abundance, and habitat availability that may 
result from these effects. While these stressors may act in isolation, 
it is more probable that many stressors are acting simultaneously (or 
in combination) (Galbraith et al. 2010, p. 1176) on Neosho mucket and 
rabbitsfoot populations.

Summary of Threats

    The decline of the Neosho mucket and rabbitsfoot (described by 
Butler 2005, entire; described by Service 2010, entire) is primarily 
the result of habitat loss and degradation (Neves 1991, p. 252). Chief 
among the causes of decline, but in no particular ranking order, are 
impoundments, sedimentation, channelization, chemical contaminants, oil 
and natural gas development, and mining (Neves 1991, p. 252; Neves 
1993, pp. 4-6; Williams et al. 1993, pp. 7-9; Neves et al. 1997, pp. 60 
and 63-75; Watters 2000, pp. 262-267). These stressors have had 
profound adverse effects on Neosho mucket and rabbitsfoot populations, 
their habitats, and fish hosts.
    Regulations at the Federal level may not be providing the 
protection needed for the Neosho mucket and rabbitsfoot. For example, 8 
of the 11 (73 percent) viable rabbitsfoot populations are located in 
waters listed as impaired under section 303(d) of the CWA. In addition, 
numerous tributaries within watersheds with viable Neosho mucket and 
rabbitsfoot populations also are listed as impaired waters under 
section 303(d) of the CWA. The CWA has a stated goal to establish water 
quality standards that protect aquatic species, including mussel 
species. However, the CWA has generally been insufficient at protecting 
mussels, and adequate water quality criteria that are protective of all 
mussel life stages, particularly glochidia and juveniles, may not be 
established. Little information is known about specific sensitivities 
of mussels to various pollutants, but both species continue to decline 
due to the effects of poor water quality, contaminants, and other 
factors.
    The majority of extant Neosho mucket populations are small and 
isolated, with only one viable population remaining. The majority of 
extant rabbitsfoot populations are marginal and small (78 percent) and 
isolated (80 percent), with only two small (5 percent) and 4 viable 
populations (36 percent) not isolated from another viable population 
(Butler 2005, p. 22; Service 2010, pp. 3-8). The patchy distributional 
pattern of populations in short river reaches makes them more 
susceptible to extirpation from single catastrophic events, such as 
toxic chemical spills (Watters and Dunn 1995, p. 257). Furthermore, 
this level of isolation makes natural recolonization of extirpated 
populations virtually impossible without human intervention. Various 
nonnative species of aquatic organisms are firmly established in the 
range of the Neosho mucket and rabbitsfoot. The nonnative species that 
poses the most significant threat to the Neosho mucket and rabbitsfoot 
is the zebra mussel. Although attempts to alleviate some of these 
threats are ongoing at some locations, no populations appear to be 
without threats that are negatively impacting the species.

Determination

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Neosho mucket and the rabbitsfoot. Section 3(6) of the Act 
defines an endangered species as ``any species that is in danger of 
extinction throughout all or a significant portion of its range'' and 
defines a threatened species as ``any species that is likely to become 
endangered throughout all or a significant portion of its range within 
the foreseeable future.'' As described in detail above, these two 
species are currently at risk throughout all of their respective ranges 
due to the immediacy, severity, and scope of threats from habitat 
destruction and modification (Factor A) and other natural or manmade 
factors affecting their continued existence (Factor E). Existing 
regulatory mechanisms applicable to these species, such as the CWA, 
appear to be inadequate to reduce these threats from water quality 
degradation, in particular, chemical contaminants (Factor D). Although 
there are ongoing actions to alleviate some threats, no populations 
appear to be without current threats. These isolated species have a 
limited ability to recolonize historically occupied stream and river 
reaches and are vulnerable to natural or human-caused changes in their 
stream and river habitats.
    Their range curtailment, small population size, and isolation make 
the Neosho mucket and rabbitsfoot more vulnerable to threats such as 
sedimentation, disturbance of riparian corridors, changes in channel 
morphology, point- and nonpoint-source contaminants, urbanization, and 
invasive species and to stochastic events (such as chemical spills).

Neosho Mucket

    The Neosho mucket has been extirpated (no longer in existence) from 
approximately 62 percent of its historical range with only 9 of 16 
historical populations remaining (extant). This mussel is declining 
rangewide (eight of the nine extant populations), with only one 
remaining large, viable population. Based on the best available 
scientific and commercial information, we have determined that the 
Neosho mucket is in danger of extinction throughout all of its range. 
Therefore, we are listing it as an endangered species. In other words, 
we find that a threatened species status is not appropriate for the 
Neosho mucket due to its contracted range and only one remaining stable 
and viable population.

Rabbitsfoot

    The rabbitsfoot has been extirpated from approximately 64 percent 
of its historical range. While this species is declining rangewide, it 
sustains recruitment and population viability consistently in 11 (8 
percent of historical or 22 percent of extant distribution) large, 
extant river populations and, while reduced in numbers, it also 
sustains limited recruitment and distribution in another 17 river 
populations. Of the 17 river populations with limited recruitment and 
distribution, 15 of these populations (88 percent) are declining.
    All remaining rabbitsfoot populations continue to be reduced in 
size or quality by habitat degradation as a result of impoundments and 
dams, navigation projects, commercial and residential development, 
agriculture, chemical contaminants, mining, and oil and natural gas 
development (Factor A). Climate change could affect in-stream water 
temperatures, seasonal water flows, and mussel and fish host 
reproductive activities, including the availability of mussel fish host 
species (Factor E). Invasive species occupying rabbitsfoot habitat will 
likely cause additional displacement and recruitment interference 
(Factor E). Eight of the 11 (73 percent) viable rabbitsfoot populations 
are in watersheds that have numerous tributaries that are listed as 
impaired waters under section 303(d) of the CWA. Regulatory mechanisms 
such as the CWA have been insufficient to significantly reduce or 
remove these types of threats to rabbitsfoot (Factor D). The 
synergistic effects of threats such as these are often complex in 
aquatic environments and make it difficult to predict changes in mussel 
and fish host(s) distribution, abundance, and

[[Page 57094]]

habitat availability. These threats are probably acting simultaneously 
on the remaining rabbitsfoot populations with negative results and are 
expected to continue to do so. Thus, while rabbitsfoot sustains 11 
viable populations, these populations continue to be at risk, and the 
remaining extant populations are affected by isolation, fragmentation, 
limited recruitment and distribution, and population declines, which 
make the species particularly susceptible to extinction in the near 
future if threats continue or increase.
    While we have determined that the rabbitsfoot is not currently in 
danger of extinction, because of the threats facing the species and 
impacts to its life history, we find that the species is likely to 
become endangered in the foreseeable future throughout all of its 
range. Therefore, we are listing it as a threatened species. In other 
words, we find that endangered status is not appropriate for the 
rabbitsfoot because 8 percent of the historical populations or 22 
percent of extant populations remaining in its historical streams can 
be considered viable, but are facing subtle, pervasive threats that are 
ubiquitous in each watershed.

Significant Portion of the Range

    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The Act defines ``endangered 
species'' as any species which is ``in danger of extinction throughout 
all or a significant portion of its range,'' and ``threatened species'' 
as any species which is ``likely to become an endangered species within 
the foreseeable future throughout all or a significant portion of its 
range.'' The definition of ``species'' is also relevant to this 
discussion. The Act defines ``species'' as follows: ``The term 
`species' includes any subspecies of fish or wildlife or plants, and 
any distinct population segment (DPS) of any species of vertebrate fish 
or wildlife which interbreeds when mature.''
    Two recent district court decisions have addressed whether the SPR 
language allows the Service to list or protect less than all members of 
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp. 
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the 
Northern Rocky Mountains gray wolf (74 FR 15123, April 2, 2009); and 
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz. 
September 30, 2010), concerning the Service's 2008 finding on a 
petition to list the Gunnison's prairie dog (73 FR 6660, February 5, 
2008). The Service had asserted in both of these determinations that it 
had authority, in effect, to protect only some members of a 
``species,'' as defined by the Act (i.e., species, subspecies, or DPS), 
under the Act. Both courts ruled that the determinations were arbitrary 
and capricious on the grounds that this approach violated the plain and 
unambiguous language of the Act. The courts concluded that reading the 
SPR language to allow protecting only a portion of a species' range is 
inconsistent with the Act's definition of ``species.'' The courts 
concluded that once a determination is made that a species (i.e., 
species, subspecies, or DPS) meets the definition of ``endangered 
species'' or ``threatened species,'' it must be placed on the list in 
its entirety and the Act's protections applied consistently to all 
members of that species (subject to modification of protections through 
special rules under sections 4(d) and 10(j) of the Act).
    We evaluated the current range of the Neosho mucket and rabbitsfoot 
to determine if there is any apparent geographic concentration of 
potential threats for either species. The Neosho mucket and rabbitsfoot 
are highly restricted in their ranges, and the threats occur throughout 
their ranges. We considered the potential threats due to impoundments, 
sedimentation, channelization, chemical contaminants, oil and gas 
development, mining, and climate change. We found no concentration of 
threats because of the species' limited and curtailed ranges, and 
uniformity of the threats throughout their entire range. Having 
determined that the Neosho mucket is endangered throughout its entire 
range, it is not necessary to evaluate whether there are any 
significant portions of its range. Having determined that the 
rabbitsfoot is threatened throughout its entire range, we must next 
consider whether there are any significant portions of the range where 
the rabbitsfoot is in danger of extinction or is likely to become 
endangered in the foreseeable future.
    We found no portion of the rabbitsfoot's range where potential 
threats are significantly concentrated or substantially greater than in 
other portions of its range. Therefore, we find that factors affecting 
the species are essentially uniform throughout its range, indicating no 
portion of the range of the species warrants further consideration of 
possible endangered or threatened status under the Act. Therefore, we 
find there is no significant portion of the rabbitsfoot range that may 
warrant a different status.

Critical Habitat

    In the October 16, 2012, proposed rule to list the species (77 FR 
63440), we also determined that designation of critical habitat was 
prudent, and critical habitat was determinable, for both the Neosho 
mucket and rabbitfoot, and we proposed critical habitat for both 
species. We will issue a final determination on critical habitat for 
Neosho mucket and rabbitsfoot under the Act in the near future.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened species under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness and 
conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and requires that recovery actions be carried out for all listed 
species. The protection required by Federal agencies 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. Subsection 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed and preparation of a draft and final 
recovery plan. The recovery outline guides the immediate implementation 
of urgent recovery actions and describes the process to be used to 
develop a recovery plan. Revisions of the plan may be done to address 
continuing or new threats to the species, as new substantive 
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five 
factors that control whether a species remains endangered

[[Page 57095]]

or may be downlisted or delisted, and methods for monitoring recovery 
progress. Recovery plans also establish a framework for agencies to 
coordinate their recovery efforts and provide estimates of the cost of 
implementing recovery tasks. Recovery teams (comprising species 
experts, Federal and State agencies, nongovernmental organizations, and 
stakeholders) are often established to develop recovery plans. When 
completed, the recovery outline, draft recovery plan, and the final 
recovery plan will be available on our Web site (https://www.fws.gov/endangered), or from our Arkansas Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these species requires 
cooperative conservation efforts on private, State, and Tribal lands.
    Once 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 States of Alabama, Arkansas, 
Indiana, Illinois, Kansas, Kentucky, Louisiana, Mississippi, Missouri, 
Ohio, Oklahoma, Pennsylvania, Tennessee, and West Virginia would be 
eligible for Federal funds to implement management actions that promote 
the protection or recovery of the Neosho mucket and rabbitsfoot. 
Information on our grant programs that are available to aid species 
recovery can be found at: https://www.fws.gov/grants.
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as 
endangered or threatened and with respect to its critical habitat, if 
any is designated. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR part 402. 
Section 7(a)(4) of the Act requires Federal agencies to confer with the 
Service on any action that is likely to jeopardize the continued 
existence of a species proposed for listing or result in destruction or 
adverse modification of proposed critical habitat. If a species is 
listed subsequently, section 7(a)(2) of the Act requires Federal 
agencies to ensure that activities they authorize, fund, or carry out 
are not likely to jeopardize the continued existence of the species or 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into formal consultation with the Service.
    Federal agency actions within these species' habitat that may 
require conference or consultation or both as described in the 
preceding paragraph include, but are not limited to, the funding of, 
carrying out, or the issuance of permits for reservoir construction, 
navigation, natural gas extraction, stream alterations, discharges, 
wastewater facility development, water withdrawal projects, pesticide 
registration, mining, and road and bridge construction. This may 
include, but is not limited to, management and any other landscape-
altering activities on Federal lands administered by the Department of 
Defense, and U.S. Department of Agriculture Forest Service; issuance of 
CWA permits by the Army Corps of Engineers and EPA; construction and 
maintenance of interstate power and natural gas transmission line 
right-of-ways by the Federal Energy Regulatory Commission; and 
construction and maintenance of roads or highways by the FHWA.
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to all endangered and 
threatened wildlife. The prohibitions of section 9(a)(1) of the Act, 
codified at 50 CFR 17.21 and 17.31 for endangered and threatened 
wildlife make it illegal for any person subject to the jurisdiction of 
the United States to take (includes harass, harm, pursue, hunt, shoot, 
wound, kill, trap, capture, or collect; or to attempt any of these), 
import, export, ship in interstate commerce in the course of commercial 
activity, or sell or offer for sale in interstate or foreign commerce 
any listed species. Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 
3371-3378), it is also illegal to possess, sell, deliver, carry, 
transport, or ship any such wildlife that has been taken illegally. 
Certain exceptions apply to agents of the Service and State 
conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered and threatened wildlife species under certain 
circumstances. Regulations governing permits are codified at 50 CFR 
17.22 for endangered species, and at 17.32 for threatened species. With 
regard to endangered wildlife, a permit must be issued for the 
following purposes: For scientific purposes, to enhance the propagation 
or survival of the species, and for incidental take in connection with 
otherwise lawful activities.
    Our policy, as published in the Federal Register on July 1, 1994 
(59 FR 34272), is to identify, to the maximum extent practicable at the 
time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on planned and ongoing activities within the range of species 
proposed for listing. The following activities could potentially result 
in a violation of section 9 of the Act for the Neosho mucket and 
rabbitsfoot; this list is not comprehensive:
    (1) Collecting, handling, possessing, selling, delivering, 
carrying, or transporting of the species, including import or export 
across State lines and international boundaries that are unauthorized, 
except for properly documented antique specimens of these taxa at least 
100 years old, as defined by section 10(h)(1) of the Act;
    (2) Introduction of nonnative species that compete with or prey 
upon the Neosho mucket and rabbitsfoot, such as the introduction of a 
predator of mussels like the nonnative black carp, to any water body 
where these species occur;
    (3) The release of biological control agents that attack any life 
stage of Neosho mucket and rabbitsfoot that is unauthorized;
    (4) Modification of the channel or water flow of any stream in 
which the Neosho mucket and rabbitsfoot are known to occur that is 
unauthorized or not covered under the Act for impacts to these species; 
and
    (5) Discharge of chemicals or fill material into any waters 
supporting the Neosho mucket and rabbitsfoot that are unauthorized or 
not covered under the Act for impacts to these species.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Service's 
Ecological Services Field Office in the State where the proposed 
activities will occur. Requests for copies of the regulations 
concerning listed animals and general inquiries regarding prohibitions 
and permits may be addressed to the U.S. Fish and Wildlife Service, 
Endangered Species Permits, 1875 Century Boulevard, Suite

[[Page 57096]]

200, Atlanta, GA 30345; telephone: 404-679-7140; facsimile: 404-679-
7081.
    Under section 4(d) of the Act, the Secretary has discretion to 
issue such regulations as she deems necessary and advisable to provide 
for the conservation of threatened species. Our implementing 
regulations (50 CFR 17.31) for threatened wildlife generally 
incorporate the prohibitions of section 9 of the Act for endangered 
wildlife, except when a ``special rule'' promulgated pursuant to 
section 4(d) of the Act has been issued with respect to a particular 
threatened species. In such a case, the general prohibitions in 50 CFR 
17.31 would not apply to that species, and instead, the special rule 
would define the specific take prohibitions and exceptions that would 
apply for that particular threatened species, which we consider 
necessary and advisable to conserve the species. The Secretary also has 
the discretion to prohibit by regulation with respect to a threatened 
species any act prohibited by section 9(a)(1) of the Act. We are not 
proposing to promulgate a special section 4(d) rule, and as a result, 
all of the section 9 prohibitions, including the ``take'' prohibitions, 
will apply to the rabbitsfoot.

Required Determinations

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

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (NEPA), need not be prepared in connection 
with listing a species as an endangered or threatened species under the 
Endangered Species Act. We published a notice outlining our reasons for 
this determination in the Federal Register on October 25, 1983 (48 FR 
49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination With Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
tribes in developing programs for healthy ecosystems, to acknowledge 
that tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to tribes. We determined that tribal lands or 
their interests will not be affected by the listing of the Neosho 
mucket and rabbitsfoot.

References Cited

    A complete list of all references cited in this rule is available 
on the Internet at https://www.regulations.gov and upon request from the 
Field Supervisor, Arkansas Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this document are the staff members of the 
Arkansas Ecological Service Field Office (see FOR FURTHER INFORMATION 
CONTACT).

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

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

PART 17--[AMENDED]

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

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

0
2. Amend Sec.  17.11(h) by adding new entries for ``Mucket, Neosho'' 
and ``Rabbitsfoot'' to the List of Endangered and Threatened Wildlife 
in alphabetical order under Clams to read as set forth below:


Sec.  17.11   Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                                  Critical     Special
                                                            Historic range       endangered or         Status      When listed    habitat       rules
           Common name                Scientific name                              threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
              Clams
 
                                                                      * * * * * * *
Mucket, Neosho...................  Lampsilis             U.S.A. (AR, KS, MO,  Entire.............  E                       816           NA           NA
                                    rafinesqueana.        OK).
 
                                                                      * * * * * * *
Rabbitsfoot......................  Quadrula cylindrica   U.S.A. (AL, AR, GA,  Entire.............  T                       816           NA           NA
                                    cylindrica.           IN, IL, KS, KY,
                                                          LA, MO, MS, OH,
                                                          OK, PA, TN, WV).
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------



[[Page 57097]]

    Dated: August 26, 2013.
 Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2013-22245 Filed 9-16-13; 8:45 am]
BILLING CODE 4310-55-P