Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Tumbling Creek Cavesnail, 37663-37677 [2011-16016]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 76, Number 124 (Tuesday, June 28, 2011)]
[Rules and Regulations]
[Pages 37663-37677]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-16016]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

Docket No. FWS-R3-ES-2010-0042; MO-92210-0-0009-B4]
RIN 1018-AW90


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for Tumbling Creek Cavesnail

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), designate 
critical habitat for the Tumbling Creek cavesnail (Antrobia culveri) 
under the Endangered Species Act of 1973, as amended (Act). In total, 
approximately 25 acres (10.25 hectares) located in Taney County, 
Missouri, fall within the boundaries of the critical habitat 
designation.

DATES: This rule becomes effective on July 28, 2011.

ADDRESSES: This final rule, the associated final economic analysis, 
comments and materials received, as well as supporting documentation 
used in preparing this final rule are available on the Internet at 
https://www.regulations.gov at Docket No. FWS-R3-ES-2010-0042. These 
documents are also available for public inspection, by appointment, 
during normal business hours, at the U.S. Fish and Wildlife Service, 
Columbia Fish and Wildlife Office, 101 Park DeVille Dr., Suite A,, 
Columbia, MO 65203; telephone: 573-234-2132; facsimile: 573-234-2181.

FOR FURTHER INFORMATION CONTACT: Charles M. Scott, Field Supervisor, 
Columbia Fish and Wildlife Office, (see ADDRESSES). If you use a 
telecommunications device for the deaf (TDD), call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

[[Page 37664]]


SUPPLEMENTARY INFORMATION: 

Background

    It is our intent to discuss only those topics directly relevant to 
the development and designation of critical habitat for the Tumbling 
Creek cavesnail in this final rule. For more information on the biology 
and ecology of the Tumbling Creek cavesnail, refer to the final listing 
rule published in the Federal Register on August 14, 2002 (67 FR 
52879), and the Tumbling Creek Cavesnail Recovery Plan, which is 
available from the Columbia Missouri Ecological Services Field Office 
(see ADDRESSES) and on the Internet at https://www.regulations.gov.
    The Tumbling Creek cavesnail is a critically imperiled aquatic 
snail, endemic to a single cave stream and associated springs in Taney 
County, southwestern Missouri. The species is known only from Tumbling 
Creek and a few of its small tributaries and associated underground 
springs within Tumbling Creek Cave, and areas immediately downstream of 
the cave between the cave's natural exit and the confluence of Tumbling 
Creek with Big Creek at Schoolhouse Spring. Suitable habitat includes 
the underside of rocks, small stones, and cobble, and occasionally the 
upper surface of solid rock bottom within sections of Tumbling Creek 
that have moderate current (U.S. Fish and Wildlife Service 2003, p. 
10). The Tumbling Creek cavesnail is dependent on good water quality 
and reduced sediment loads in Tumbling Creek (Aley and Ashley 2003, p. 
20).
    The primary threats are related to the degradation of water quality 
in Tumbling Creek and include increased siltation from overgrazing, 
tree removal, and other activities. Nonpoint source pollution within 
the recharge area of Tumbling Creek cave is also a threat to the 
species (Aley and Ashley 2003, p. 19; U.S. Fish and Wildlife Service 
2003, pp. 14-18). The deposition of silt into Tumbling Creek from 
aboveground activities within the recharge area of Tumbling Creek Cave 
has likely contributed to the decline of the species by eliminating the 
species' habitat, covering egg masses, or adversely impacting the snail 
in other ways (Tom and Cathy Aley, 2001, pers. comm.; U.S. Fish and 
Wildlife Service 2001, p. 66806; Aley and Ashley 2003, p. 19; U.S. Fish 
and Wildlife Service 2003, pp. 14-18).

Previous Federal Actions

    The Tumbling Creek cavesnail was emergency listed on December 27, 
2001 (66 FR 66803) and subsequently listed as endangered on August 14, 
2002 (67 FR 52879). At the time of listing, we determined that a delay 
in designating critical habitat would enable us to concentrate our 
limited resources on other actions that must be addressed and allow us 
to invoke immediate protections needed for the conservation of the 
species. We concluded that, if prudent and determinable, we would 
prepare a critical habitat proposal in the future at such time as our 
available resources and other listing priorities under the Act would 
allow. We approved a final recovery plan for the Tumbling Creek 
cavesnail on September 15, 2003, and announced its availability to the 
public through a notice published in the Federal Register on September 
22, 2003 (68 FR 55060).
    On August 11, 2008, the Institute for Wildlife Protection and 
Crystal Grace Rutherford filed a lawsuit against the Secretary of the 
Interior for our failure to timely designate critical habitat for the 
Tumbling Creek cavesnail (Institute for Wildlife Protection et al. v. 
Kempthorne (07-CV-01202-CMP)). In a court-approved settlement 
agreement, we agreed to submit to the Federal Register a new prudency 
determination, and if the designation was found to be prudent, a 
proposed designation of critical habitat, by June 30, 2010, and a final 
designation by June 30, 2011. We published the proposed critical 
habitat designation for the Tumbling Creek cavesnail on June 23, 2010 
(75 FR 35751). Publication of the proposed rule opened a 60-day public 
comment period that closed on August 23, 2010. We reopened the public 
comment period for an additional 30 days (ending February 11, 2011), in 
order to announce the availability of and receive comments on a draft 
economic analysis (DEA) (76 FR 2076).

Summary of Comments and Recommendations

    We requested written comments from the public on the proposed 
designation of critical habitat for the Tumbling Creek cavesnail during 
two comment periods. The first comment period associated with the 
publication of the proposed rule (75 FR 35751) opened on June 23, 2010, 
and closed on August 23, 2010. We also requested comments on the 
proposed critical habitat designation and associated draft economic 
analysis during a comment period that opened January 12, 2011, and 
closed on February 11, 2011 (76 FR 2076). We contacted appropriate 
Federal, State, and local agencies; scientific organizations; and other 
interested parties and invited them to comment on the proposed rule and 
the associated DEA during these comment periods.
    During the first comment period, we received four comment letters 
directly addressing the proposed critical habitat designation. During 
the second comment period, we received one comment letter addressing 
the proposed critical habitat designation and the DEA. We did not 
receive any requests for a public hearing, so no public hearing was 
held. All substantive information provided during comment periods has 
either been incorporated directly into this final determination or 
addressed below. Comments received, including comments from peer 
reviewers (see below) were grouped into three general issues 
specifically relating to the proposed critical habitat designation for 
the Tumbling Creek cavesnail and are addressed in the following summary 
and incorporated into the final rule as appropriate.

Peer Review

    In accordance with our peer review policy published in the Federal 
Register on July 1, 1994 (59 FR 34270), we solicited expert opinions 
from three knowledgeable individuals with scientific expertise that 
included familiarity with the species, the geographic region in which 
the species occurs, the hydrology and geology associated with karst 
systems, and conservation biology principles. We received responses 
from all three of the peer reviewers.
    We reviewed all comments received from the peer reviewers for 
substantive issues and new information regarding critical habitat for 
the Tumbling Creek cavesnail. All peer reviewers strongly supported the 
proposed rule and believed that our analysis was based on solid 
science. Peer reviewers provided additional information and editorial 
suggestions to improve the final critical habitat rule. Peer reviewer 
comments are addressed in the following summary and incorporated into 
the final rule as appropriate.

Peer Reviewer Comments

    Comment 1: All three peer reviewers noted that there was a 
typographical error relative to dissolved oxygen concentrations on page 
35755 (first column, second paragraph) of the proposed rule (75 FR 
35751; June 23, 2010). They identified that we mistakenly stated that 
``dissolved oxygen levels should not exceed 4.5 milligrams per liter.'' 
The corrected statement should be that dissolved oxygen levels should 
always equal or exceed 4.5 milligrams per liter.

[[Page 37665]]

    Our Response: We agree that we had inadvertently reversed the 
required limit and have corrected it in this final rule.
    Comment 2: Critical habitat should include the entire 23.57 square 
kilometers (9.1 square miles) within the recharge area of Tumbling 
Creek cave, not just the cave stream.
    Our Response: While important to the species, the defined recharge 
area for Tumbling Creek cave does not meet the Act's definition for 
critical habitat. For inclusion in a critical habitat designation, the 
habitat within the geographical area occupied by the species at the 
time it was listed must contain the physical and biological features 
essential to the conservation of the species, and may be included only 
if those features may require special management considerations or 
protection. Critical habitat designations identify, to the extent known 
using the best scientific and commercial data available, habitat areas 
that provide essential life-cycle needs of the species (areas on which 
are found the physical and biological features laid out in the 
appropriate quantity and spatial arrangement for the conservation of 
the species). Because the Tumbling Creek cavesnail is an obligate 
stream snail, nonaquatic habitats within the recharge area of Tumbling 
Creek would not meet the Act's definition of critical habitat in that 
they do not contain the physical and biological features essential to 
the conservation of the species as described in this rule. Therefore, 
those areas are not included in the critical habitat designation. 
Nonetheless, the Service acknowledges that the proper management and 
maintenance of these areas are important to the long-term recovery of 
the Tumbling Creek cavesnail, and applicable conservation measures are 
outlined in the final Recovery Plan for the species.
    Comment 3: One peer reviewer stated that there was no evidence that 
the Tumbling Creek cavesnail currently occupies underground areas 
between the natural exit of Tumbling Creek cave and the confluence of 
Tumbling Creek with Bear Cave Hollow upstream of Big Creek.
    Our Response: These areas have not been surveyed due to their 
inaccessibility to humans. Snails could occur in phreatic (cracks and 
crevices) in the underground karst that provide sufficient aquatic 
habitat. Therefore, because we believe these areas could reasonably be 
occupied by the cavesnail, and they contain the physical and biological 
features essential to the conservation of the species, it is 
appropriate to include these areas in the critical habitat designation.
    Comment 4: Two peer reviewers thought that the discussion on the 
importance of energy input from gray bat (Myotis grisescens) guano 
should be expanded to highlight the potential catastrophic impact that 
White-nose Syndrome (WNS) and the causative fungus, Geomyces 
destructans could have on the Tumbling Creek cavesnail if WNS decimates 
gray bat populations in Tumbling Creek cave.
    Our Response: The Service agrees that such an expanded discussion 
is warranted and we have incorporated additional information on the 
potential impact of WNS in this final rule.

Public Comments

    Comment 5: One commenter noted that the surface stream upstream of 
the cave on the map (75 FR 35763; June 23, 2010) was incorrectly 
labeled and is identified as Bear Cave Hollow. This commenter stated 
that Tumbling Creek merges with Bear Cave Hollow upstream of Big Creek 
and that the mistake was due to an error on the U.S. Geological Survey 
Protem 7.5 minute topographic map that incorrectly lists Tumbling Creek 
as an alternate name for Bear Cave Hollow.
    Our Response: We have made this correction on the map (Figure 1) 
and have incorporated the change in this final rule. Additionally, we 
have incorporated changes to note that the area designated as critical 
habitat is from the emergence of Tumbling Creek within Tumbling Creek 
cave to its confluence with Bear Cave Hollow upstream of Big Creek. 
These changes, however, will not affect the area outlined in the 
critical habitat designation or its total acreage.
    Comment 6: While not presenting a position on the Service's 
proposed critical habitat designation, the Little Rock District of the 
Army Corps of Engineers (COE) commented that they do not believe that 
the designation of critical habitat for the Tumbling Creek cavesnail 
would necessitate further consultation under Section 7(a)(2) of the Act 
related to the operation of Bull Shoals Reservoir.
    Our Response: During discussions with the Corps on February 8, 
2011, the Service reiterated its intention to reinitiate formal 
consultation on the project for the cavesnail because of new 
information regarding the status of the species, its presumed occupied 
range, the potential threat of white nose syndrome (as it may affect 
the energy input from the guano of bats that roost in Tumbling Creek 
Cave), and the designation of critical habitat. That consultation would 
also assess whether any actions associated with the operations of Bull 
Shoals Reservoir would likely jeopardize the continued existence of the 
cavesnail or adversely modify designated critical habitat.
    Comment 7: One commenter also noted that there was a typographical 
error relative to dissolved oxygen concentrations on page 35755 (first 
column, second paragraph) of the proposed rule (75 FR 35751; June 23, 
2010). They identified that we mistakenly stated that ``dissolved 
oxygen levels should not exceed 4.5 milligrams per liter.'' The 
corrected statement should be that dissolved oxygen levels should 
always equal or exceed 4.5 milligrams per liter.
    Our Response: Refer to our response to Comment 1.
    Comment 8: One commenter also thought that the discussion on the 
importance of energy input from gray bat (Myotis grisescens) guano 
should be expanded to highlight the potential catastrophic impact that 
White-nose Syndrome (WNS) and the causative fungus, Geomyces 
destructans could have on the Tumbling Creek cavesnail if WNS decimates 
gray bat populations in Tumbling Creek cave.
    Our Response: Refer to our response to Comment 4.

Summary of Changes From Proposed Rule

    We thoroughly evaluated all comments received on the proposed 
designation of critical habitat. As a result of the comments we 
received on the proposed rule, as well as errors we found, we have made 
the following changes to our proposed designation.
     Changed a typographical error related to a misstatement 
regarding the correct dissolved oxygen levels identified as one of the 
physical and biological features essential to the conservation of the 
Tumbling Creek cavesnail.
     Relabeled the map to depict the difference between 
Tumbling Creek and Bear Cave Hollow that was incorrectly labeled on the 
U.S. Geological Survey Protem 7.5 minute topographic map.
     Changed the relevant portions of the text in this rule to 
note that the area designated as critical habitat is from the emergence 
of Tumbling Creek within Tumbling Creek cave to its confluence with 
Bear Cave Hollow upstream of Big Creek. These changes, however, do not 
affect the area outlined in the critical habitat designation, or its 
total acreage.
     In preparing the final rule, the Service noted a 
typographical error related to the area of the above-ground recharge 
listed for Tumbling Creek cave.

[[Page 37666]]

The area should be listed as 23.57 square kilometers (9 square miles), 
not 14.5 kilometers (9 miles) as stated in the proposed rule. The 
appropriate change has been made in this final rule and does not change 
the total acreage included in the designation.
    In preparing the final rule and relabeling the map outlining 
critical habitat for the Tumbling Creek cavesnail, the Service noticed 
that the designation does not include Schoolhouse Spring as stated in 
the proposed rule. The only spring within the designation is Owens 
Spring. The landowner confirmed that the area depicted in our map only 
includes Owens Spring and not Schoolhouse Spring. The removal of 
references to Schoolhouse Spring in the description of the area 
designated as critical habitat does not change the map or the total 
acreage included in the designation.

Critical Habitat

Background

    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features
    (a) Essential to the conservation of the species, and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Conservation, as defined under section 3 of the Act, means to use 
and the use of all methods and procedures that are necessary to bring 
an endangered or threatened species to the point at which the measures 
provided under the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management, such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping and transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot be otherwise 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7(a)(2) of the 
Act through the prohibition against Federal agencies carrying out, 
funding, or authorizing the destruction or adverse modification of 
critical habitat. Section 7(a)(2) requires consultation on Federal 
actions that may affect critical habitat. The designation of critical 
habitat does not affect land ownership or establish a refuge, 
wilderness, reserve, preserve, or other conservation area. Such 
designation does not allow the government or public to access private 
lands. Such designation does not require implementation of restoration, 
recovery, or enhancement measures by non-Federal landowners. Where a 
landowner seeks or requests Federal agency funding or authorization for 
an action that may affect a listed species or critical habitat, the 
consultation requirements of section 7(a)(2) would apply, but even in 
the event of a destruction or adverse modification finding, the 
obligation of the Federal action agency and the landowner is not to 
restore or recover the species, but to implement reasonable and prudent 
alternatives to avoid destruction or adverse modification of critical 
habitat.
    For inclusion in a critical habitat designation, the habitat within 
the geographical area occupied by the species at the time it was listed 
must contain the physical or biological features that are essential to 
the conservation of the species and which may require special 
management considerations or protection. Critical habitat designations 
identify, to the extent known using the best scientific and commercial 
data available, those physical and biological features that are 
essential to the conservation of the species (such as space, food, 
cover, and protected habitat), focusing on the principal biological or 
physical constituent elements (primary constituent elements) within an 
area that are essential to the conservation of the species (such as 
roost sites, nesting grounds, seasonal wetlands, water quality, tide, 
soil type). Primary constituent elements are the elements of physical 
and biological features that, when laid out in the appropriate quantity 
and spatial arrangement to provide for a species' life-history 
processes, are essential to the conservation of the species.
    Under the Act, we can designate critical habitat in areas outside 
the geographical area occupied by the species at the time it is listed, 
upon a determination that such areas are essential for the conservation 
of the species. We designate critical habitat in areas outside the 
geographical area occupied by a species only when a designation limited 
to its range would be inadequate to ensure the conservation of the 
species. When the best available scientific data do not demonstrate 
that the conservation needs of the species require such additional 
areas, we will not designate critical habitat in areas outside the 
geographical area occupied by the species. An area currently occupied 
by the species but that was not occupied at the time of listing may, 
however, be essential to the conservation of the species and may be 
included in the critical habitat designation.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, our Policy on Information Standards under the Endangered 
Species Act (published in the Federal Register on July 1, 1994 (59 FR 
34271)), the Information Quality Act (section 515 of the Treasury and 
General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 
106-554; H.R. 5658)), and our associated Information Quality 
Guidelines, provide criteria, establish procedures, and provide 
guidance to ensure that our decisions are based on the best scientific 
data available. They require our biologists, to the extent consistent 
with the Act and with the use of the best scientific data available, to 
use primary and original sources of information as the basis for 
recommendations to designate critical habitat.
    When we are determining which areas we should designate as critical 
habitat, our primary source of information is generally the information 
developed during the listing process for the species. Additional 
information sources may include the recovery plan for the species, 
articles in peer-reviewed journals, conservation plans developed by 
States and counties, scientific status surveys and studies, biological 
assessments, or other unpublished materials and expert opinion or 
personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. In particular, we recognize that climate change may cause 
changes in the arrangement of occupied habitat stream reaches. Climate 
change may lead to increased frequency and duration of droughts (Rind 
et al. 1990, p. 9983; Seager et al. 2007, pp. 1181-1184; Rahel and 
Olden 2008, p. 526). Climate warming may increase the virulence of 
nonnative parasites and pathogens to native species (Rahel and Olden 
2008, p. 525), decrease groundwater levels (Schindler 2001, p. 22), or 
significantly reduce annual stream flows (Moore et al. 1997, p. 925). 
Increased drought conditions and prolonged low flows associated with 
climate change may favor the establishment and spread of nonnative

[[Page 37667]]

species (Rahel and Olden 2008, pp. 526, 529-530). In the Missouri 
Ozarks, it is projected that stream basin discharges may be 
significantly impacted by synergistic effects of changes in land cover 
and climate change (Hu et al. 2005, p. 9).
    The information currently available on the effects of global 
climate change and increasing temperatures does not make sufficiently 
precise estimates of the location and magnitude of the effects. Nor are 
we currently aware of any climate change information specific to the 
habitat of the Tumbling Creek cavesnail that would indicate what areas 
may become important to the species in the future. Nonetheless, because 
the Tumbling Creek cavesnail is an aquatic snail that is totally 
dependent upon an adequate water supply, adverse effects associated 
with climate change that could significantly alter the quantity and 
quality of Tumbling Creek could impact the species in the future. Other 
than Tumbling Creek, we are currently unaware of any other cave stream 
inhabited by the Tumbling Creek cavesnail. Therefore, as explained in 
the proposed rule (75 FR 35751), we are unable to determine which 
additional areas, if any, may be appropriate to include in the final 
critical habitat for this species to address the effects of climate 
change.
    We recognize that critical habitat designated at a particular point 
in time may not include all of the habitat areas that we may later 
determine are necessary for the recovery of the species, especially if 
future surveys are successful in documenting the species' presence in 
another cave stream. For these reasons, a critical habitat designation 
does not signal that habitat outside the designated critical habitat 
area is unimportant or may not be required for recovery of the species.
    Areas that are important to the conservation of the species, but 
are outside the critical habitat designation, will continue to be 
subject to conservation actions we implement under section 7(a)(1) of 
the Act. They are also subject to the regulatory protections afforded 
by the section 7(a)(2) jeopardy standard, as determined based on the 
best available scientific information at the time of the agency action. 
Federally funded or permitted projects affecting listed species outside 
their designated critical habitat areas may still result in jeopardy 
findings in some cases. Similarly, critical habitat designations made 
on the basis of the best available information at the time of 
designation will not control the direction and substance of future 
recovery plans, habitat conservation plans (HCPs), section 7 
consultations, or other species conservation planning efforts if new 
information available at the time of these planning efforts calls for a 
different outcome.

Physical and Biological Features

    In accordance with sections 3(5)(A)(i) and 4(b)(1)(A) of the Act 
and the regulations at 50 CFR 424.12, in determining which areas within 
the geographical area occupied at the time of listing to designate as 
critical habitat, we consider the physical and biological features that 
are essential to the conservation of the species, which may require 
special management considerations or protection. These include, but are 
not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, or rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical, and ecological 
distributions of a species.
    We derive the specific essential physical and biological features 
for the Tumbling Creek cavesnail from studies on this species' habitat, 
ecology, and life history as described in the Critical Habitat section 
of the proposed rule to designate critical habitat published in the 
Federal Register on June 23, 2010 (75 FR 35751), and in the information 
presented below. Additional information can be found in the Background 
and Status and Distribution sections of the final listing rule 
published in the Federal Register on August 14, 2002 (67 FR 52879), and 
the final recovery plan for the species available on the Internet at 
https://ecos.fws.gov/docs/recovery_plans/2003/030922a.pdf. 
Unfortunately, little is known of the specific habitat requirements for 
this species other than that the species requires adequate water 
quality, water quantity, water flow, a stable stream channel, minimal 
sedimentation, and energy input from the guano of bats, particularly 
gray bats (Myotis grisescens) that roost in Tumbling Creek Cave. To 
identify the physical and biological features essential to the Tumbling 
Creek cavesnail, we have relied on current conditions at locations 
where the species survives, and the limited information available on 
this species and its close relatives.
Space for Individual and Population Growth and for Normal Behavior
    The specific space requirements for the Tumbling Creek cavesnail 
are unknown, but given that 15,118 snails were estimated in a 1,016-
square-meter (3,333-square-foot) area of Tumbling Creek in 1973 
(Greenlee 1974, p. 10), space is not likely a limiting factor for the 
species. The loss of interstitial habitats for the species, however, 
likely contributed to the species decline (U.S. Fish and Wildlife 
Service 2003, p. 14).
Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements
    It is believed that the species feeds on biofilm, the organic 
coating and bacterial layer associated with the underside of rocks or a 
bare rock stream bottom (Aley and Ashley 2003, p. 19). This biofilm is 
directly connected to energy input from the guano of a large colony of 
roosting bats in Tumbling Creek Cave, particularly the Federally listed 
gray bat (Myotis grisescens) (Aley and Ashley 2003, p.18; U.S. Fish and 
Wildlife Service 2003, p. 11). The cavesnail is often found on rocks 
coated with manganese oxide (Aley and Ashley 2003, p. 18), but it is 
unlikely, however, that manganese minerals play any role in the growth 
and survival of the cavesnail (Ashley 2010, pers. comm.).
Cover or Shelter
    The Tumbling Creek cavesnail has been found on both the upper and 
lower surfaces of rocks and gravel (Greenlee 1974, p. 10; Aley and 
Ashley 2003, p. 18; U.S. Fish and Wildlife Service 2003, p. 12). Flow 
rates in Tumbling Creek can reach 150 cubic feet per second (cfs) 
during flash flood events (Aley 2010, pers. comm.), and such events may 
dislodge cavesnails from the upper surface of substrates. Consequently, 
it is likely that the underside of larger rocks provides some cover for 
cavesnails. Rocks and gravel are used by cavesnails for attachment 
(Greenlee 1974, p. 10; U.S. Fish and Wildlife Service, p. 12). 
Additionally, it is likely that a stable stream bottom and cave stream 
banks and riffle, run, and pool habitats are important components of 
the species' habitat.
    In summary, the Tumbling Creek cavesnail depends on stable stream 
bottoms and banks (stable horizontal dimension and vertical profile) 
that maintain bottom features (riffles, runs, and pools) and transition 
zones between bottom features. Furthermore, the species requires bottom 
substrates consisting of fine gravel with coarse gravel or cobble, or 
bedrock with sand

[[Page 37668]]

and gravel, with low amounts of fine sand and sediments within the 
interstitial spaces of the substrates.
Sites for Breeding, Reproduction, or Rearing
    Like other members of the snail family Hydrobiidae, the Tumbling 
Creek cavesnail has separate male and female individuals (Aley and 
Ashley 2003, p. 19), but there is no information on the mating behavior 
of the species or what role the unknown sex ratio of the species may 
have on successful reproduction. Eggs are likely deposited in 
gelatinous egg masses, but to date, the occurrence of such egg masses 
has yet to be documented (Aley and Ashley 2003, p. 19). Although little 
is known about the reproductive behavior and development of offspring 
of the Tumbling Creek cavesnail, it is likely that rock and gravel 
substrates that are free from silt are important elements necessary for 
successful propagation, especially for attachment of gelatinous egg 
masses. Aley and Ashley (2003, p. 19) postulated that silt deposited in 
Tumbling Creek could smother egg masses, and Ashley (2000, p. 8) 
suggested that silt could suffocate early developmental stages of the 
cavesnail. The lifespan of the Tumbling Creek cavesnail is unknown, 
but, if similar to other surface-dwelling hydrobid snails that have 
been studied, it is probably between 1 and 5 years (Aley and Ashley 
2003, p. 19).
    The cavesnail is dependent on good water quality (Aley and Ashley 
2003, pp. 19-20; U.S. Fish and Wildlife Service 2003, pp. 13-22). Aley 
(2001, pers. comm.; U.S. Fish and Wildlife Service 2003, p. 22) noted 
that oxygen depletion could occur in Tumbling Creek during low flows; 
therefore, permanent flow of the stream is apparently important to the 
survival of the cavesnail. Aley (2010, pers. comm.) calculated that an 
average daily discharge of 0.07-150 cubic feet per second (cfs) was 
necessary to maintain good water quality for the cavesnail. Aley (2010, 
pers. comm.) also postulated that, to ensure good water quality for the 
Tumbling Creek cavesnail, water temperature of the cave stream should 
be 55-62 [deg]F (12.78-16.67 [deg]C), dissolved oxygen levels should 
equal or exceed 4.5 milligrams per liter, and turbidity of an average 
monthly reading should not exceed 200 Neophelometric Units (NTU; units 
used to measure sediment discharge) and should not persist for a period 
greater than 4 hours.
    In summary, the Tumbling Creek cavesnail depends on an instream 
flow regime with an average daily discharge between 0.07 and 150 cubic 
feet per second (cfs), inclusive of both surface runoff and groundwater 
sources (springs and seepages), and water quality with temperature 55-
62 [deg]F (12.78-16.67 [deg]C), dissolved oxygen 4.5 milligrams or 
greater per liter, and turbidity of an average monthly reading of no 
more than 200 NTUs for a duration not to exceed 4 hours.
Primary Constituent Elements for the Tumbling Creek Cavesnail
    Under the Act and its implementing regulations, we are required to 
identify the physical and biological features essential to the 
conservation of the Tumbling Creek cavesnail in areas occupied at the 
time of listing and focus on the features' primary constituent 
elements. We consider primary constituent elements to be the elements 
of physical and biological features, that, when laid out in the 
appropriate quantity and spatial arrangement to provide for a species' 
life-history processes, are essential to the conservation of the 
species.
    Based on our current knowledge of the physical or biological 
features and habitat characteristics to sustain the species' life-
history processes, we determine that the primary constituent elements 
specific to the Tumbling Creek cavesnail are:
    (1) Geomorphically stable stream bottoms and banks (stable 
horizontal dimension and vertical profile) in order to maintain bottom 
features (riffles, runs, and pools) and transition zones between bottom 
features; to continue appropriate habitat to maintain essential 
riffles, runs, and pools; and to promote connectivity between Tumbling 
Creek and its tributaries and associated springs to maintain gene flow 
throughout the population.
    (2) Instream flow regime with an average daily discharge between 
0.07 and 150 cubic feet per second (cfs), inclusive of both surface 
runoff and groundwater sources (springs and seepages).
    (3) Water quality with temperature 55-62 [deg]F (12.78-16.67 
[deg]C), dissolved oxygen 4.5 milligrams or greater per liter, and 
turbidity of an average monthly reading of no more than 200 
Nephelometric Turbidity Units (NTU; units used to measure sediment 
discharge) for a duration not to exceed 4 hours.
    (4) Bottom substrates consisting of fine gravel with coarse gravel 
or cobble, or bedrock with sand and gravel, with low amounts of fine 
sand and sediments within the interstitial spaces of the substrates.
    (5) Energy input from guano that originates mainly from gray bats 
that roost in the cave; guano is essential in the development of 
biofilm (the organic coating and bacterial layer that covers rocks in 
the cave stream) that cavesnails use for food.
    With this designation of critical habitat, we intend to identify 
the physical and biological features essential to the conservation of 
the species, through the identification of the appropriate quantity and 
spatial arrangement of the primary constituent elements sufficient to 
support the life-history processes of the species. The unit designated 
as critical habitat is currently occupied by the Tumbling Creek 
cavesnail and contains the primary constituent elements in the 
appropriate quantity and spatial arrangement sufficient to support the 
life-history needs of the species.

Special Management Considerations or Protections

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing contain the physical and biological features that are 
essential to the conservation of the species and that may require 
special management considerations or protection.
    The one unit we are designating as critical habitat will require 
some level of management to address the current and future threats to 
the physical and biological features essential to the conservation of 
the species. Although no portion of the designated critical habitat 
unit is presently under special management or protection provided by a 
legally operative plan or agreement for the conservation of the 
Tumbling Creek cavesnail, the cave owners Tom and Cathy Aley have been 
actively involved in implementing numerous conservation measures that 
continue to contribute to the recovery of the species. Various 
activities in or adjacent to the critical habitat unit described in 
this final rule may affect one or more of the primary constituent 
elements. For example, features in the critical habitat designation may 
require special management due to threats associated with management of 
water levels on Bull Shoals Reservoir (such as increased sedimentation 
or bank erosion from backwater flooding); by significant changes in the 
existing flow regime of Tumbling Creek, its tributaries, or associated 
springs; by significant alteration of water quality; by significant 
alteration in the quantity of groundwater and alteration of spring 
discharge sites; by alterations to septic

[[Page 37669]]

systems that could adversely affect the water quality of Tumbling 
Creek; and by other watershed and floodplain disturbances that release 
sediments or nutrients into the water.
    Energy input in the form of bat guano is identified above as an 
important primary constituent element for the Tumbling Creek cavesnail. 
Most of the bat guano in Tumbling Creek cave originates from a large 
population of gray bats that roost in the cave (Aley and Ashley 2003, 
p. 18; U.S. Fish and Wildlife Service 2003, p. 11). White-nose Syndrome 
(WNS) and the causative fungus, Geomyces destructans is estimated to be 
responsible for as much as a 75 percent decline in some bat populations 
in the eastern United States since WNS was first documented in 2006 
(Blehert et al. 2009, p. 227; Frick et al. 2010, p. 679; Puechmaille et 
al. 2010, p. 290). Geomyces destructans has been recently documented on 
gray bats in Missouri (LeAnn White 2010, pers. comm.; Swezey and 
Garrity 2011, p. 16). The likely continued spread of WNS to gray bats 
in Missouri could be catastrophic for the species (U.S. Fish and 
Wildlife Service 2009, pp. 12-13). The spread of WNS on gray bats in 
Tumbling Creek cave could eliminate the species from the site and 
impact all cave-dwelling species, including the cavesnail, due to the 
loss of energy input from the lack of bat guano.
    Other activities that may affect the primary constituent elements 
in the designated critical habitat unit include those listed in the 
``Effects of Critical Habitat Designation'' section below. The 
designation of critical habitat does not imply that lands outside of 
critical habitat do not play an important role in the conservation of 
the Tumbling Creek cavesnail. Activities with a Federal nexus that may 
affect areas outside of critical habitat, such as development; road 
construction and maintenance; oil, gas, and utility easements; forest 
and pasture management; maintenance of Bull Shoals Reservoir; and 
effluent discharges, are still subject to review under section 7 of the 
Act if they may affect the Tumbling Creek cavesnail, because Federal 
agencies must consider both effects to the species and effects to 
critical habitat independently. The Service should be consulted 
regarding disturbances to areas both within the designated critical 
habitat unit as well as areas within the recharge area of Tumbling 
Creek cave, including springs and seeps that contribute to the instream 
flow in the tributaries, especially during times when stream flows are 
abnormally low (during droughts), because these activities may impact 
the essential features of the designated critical habitat. The 
prohibitions of section 9 of the Act against the take of listed species 
also continue to apply both inside and outside of designated critical 
habitat.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(1)(A) of the Act, we used the best 
scientific and commercial data available to designate critical habitat. 
We reviewed available information pertaining to the habitat 
requirements of this species. In accordance with the Act and its 
implementing regulation at 50 CFR 424.12(e), we considered whether 
designating additional areas--outside those currently occupied as well 
as those occupied at the time of listing--are necessary to ensure the 
conservation of the species. We are not designating any areas outside 
the geographical area occupied by the species because occupied areas 
are sufficient for the conservation of the species, adjacent caves 
surveyed for the cavesnail failed to document the species (U.S. Fish 
and Wildlife Service 2003, p. 4), and there is no known habitat within 
a certain radius of Tumbling Creek cave which provides a combination of 
aquatic substrate and a large source of energy input that is necessary 
for the conservation of the species. We are designating critical 
habitat in areas within the geographical area occupied by the species 
at the time of listing in 2002.
    In order to determine which sites were occupied at the time of 
listing, we used information from surveys conducted by Greenlee (1974, 
pp. 9-11) and Ashley (2010, pers. comm.), data summarized in the final 
listing rule (67 FR 52879), the Tumbling Creek Cavesnail Recovery Plan 
(U.S. Fish and Wildlife Service 2003, pp. 1-13), and personal 
observations by cave owners Tom and Cathy Aley. Currently, occupied 
habitat for the species is limited and isolated to Tumbling Creek, from 
its emergence in Tumbling Creek Cave to its confluence with Bear Cave 
Hollow and Owens Spring upstream of Big Creek.
    Following the identification of the specific locations occupied by 
the Tumbling Creek cavesnail, we determined the appropriate length of 
occupied segments of Tumbling Creek by identifying the upstream and 
downstream limits of these occupied sections necessary for the 
conservation of the species. Because Tumbling Creek is intricately 
linked with fractures in chert rock and associated springs and 
underground portions that are inaccessible to humans, we determined 
that currently occupied habitat includes the area from the emergence of 
Tumbling Creek within Tumbling Creek Cave to its confluence with Bear 
Cave Hollow and Owens Spring upstream of Big Creek. This determination 
was made to ensure incorporation of all potential sites of occurrence. 
These portions of Tumbling Creek and Owens Spring were then digitized 
using 7.5' topographic maps and ArcGIS to produce the critical habitat 
map.
    We are designating as critical habitat all portions of Tumbling 
Creek and the underground portions of Owens Spring as occupied habitat. 
We have defined ``occupied habitat'' as those stream reaches documented 
at the time of listing and all portions of Tumbling Creek between its 
emergence in Tumbling Creek Cave and its confluence with Bear Cave 
Hollow and Owens Spring upstream of Big Creek. Although there are 
underground portions of Tumbling Creek that are inaccessible to humans, 
the entire stream length is believed to be occupied by the Tumbling 
Creek cavesnail; thus, the entire stream is believed to comprise the 
entire known range of the Tumbling Creek cavesnail. We are not 
designating any areas outside of those mentioned above, because the 
species is believed to be a site endemic, and surveys in other nearby 
cave streams and springs have failed to find additional populations 
(U.S. Fish and Wildlife Service 2003, p. 4).
    The one unit contains all of the physical and biological features 
in the appropriate quantity and spatial arrangement essential to the 
conservation of this species and supports all life processes for the 
Tumbling Creek cavesnail.
    Although the above-ground recharge area of Tumbling Creek Cave 
(estimated to be 9 square miles (23.57 square kilometers) (U.S. Fish 
and Wildlife Service 2003, p. 14)) is important to maintain the 
condition of cavesnail habitat, such areas do not themselves contain 
the physical and biological features essential to the conservation of 
the species, and are, therefore, not designated as critical habitat.
    To the best of our knowledge, there are no unoccupied areas that 
are essential to the conservation of the Tumbling Creek cavesnail. All 
of the areas designated as critical habitat for the Tumbling Creek 
cavesnail are currently occupied by the species and contain the 
essential physical and biological features. All of the areas designated 
as critical habitat are also within the known historical range of the 
species. Therefore, we are not designating any areas outside the

[[Page 37670]]

geographical area occupied by the species at the time of listing. We 
believe that the occupied areas are sufficient for the conservation of 
the species.

Final Critical Habitat Designation

    We are designating one unit, totaling approximately 25 ac (10.12 
ha), as critical habitat for the Tumbling Creek cavesnail. The critical 
habitat unit described below constitutes our best assessment of areas 
that currently meet the definition of critical habitat for the Tumbling 
Creek cavesnail.
    We present a brief description for the unit and reasons why it 
meets the definition of critical habitat below. The designated critical 
habitat unit includes the stream channel of Tumbling Creek to the 
confluence with Bear Cave Hollow and Owens Spring upstream of Big 
Creek. For the one stream reach designated as critical habitat, the 
upstream and downstream boundaries are described generally below; more 
precise descriptions are provided in the Regulation Promulgation at the 
end of this final rule.

Tumbling Creek, Taney County, Missouri

    The unit includes the entire length of Tumbling Creek, from its 
emergence in Tumbling Creek Cave (southeast of the intersection of 
Routes 160 and 125) downstream to its confluence with Bear Cave Hollow 
and Owens Spring upstream of Big Creek, encompassing 25 ac (10.12 ha). 
This section of Tumbling Creek and the associated spring are under 
private ownership by Tom and Cathy Aley of the Ozark Underground 
Laboratory and contain all of the essential physical and biological 
features necessary for the Tumbling Creek cavesnail.
    Threats to the essential physical and biological features necessary 
for the Tumbling Creek cavesnail that may require special management 
and protection include:
     Actions associated with the management of water levels of 
Bull Shoals Reservoir (such as increased sedimentation or bank erosion 
on the terminal portions of Tumbling Creek from backwater flooding);
     Significant changes in the existing flow regime of 
Tumbling Creek, its tributaries. or associated springs;
     Significant alteration of water quality;
     Significant alteration in the quantity of groundwater and 
spring discharge sites;
     Alterations to septic systems that could adversely affect 
the quality of Tumbling Creek;
     Other watershed and floodplain disturbances that release 
sediments or nutrients into the water;
     The accidental introduction of nonnative aquatic species 
into the stream due to backwater flooding of Bull Shoals Reservoir into 
Tumbling Creek; or
     The potential effects of WNS on bats occupying the cave.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that actions they fund, authorize, or carry out are 
not likely to destroy or adversely modify critical habitat. Decisions 
by the 5th and 9th Circuits Courts of Appeals have invalidated our 
definition of ``destruction or adverse modification'' (50 CFR 402.02) 
(see Gifford Pinchot Task Force v. U.S. Fish and Wildlife Service, 378 
F.3d 1059 (9th Cir. 2004) and Sierra Club v. U.S. Fish and Wildlife 
Service, 245 F.3d 434, 442 (5th Cir. 2001)), and we do not rely on this 
regulatory definition when analyzing whether an action is likely to 
destroy or adversely modify critical habitat. Under the statutory 
provisions of the Act, we determine destruction or adverse modification 
on the basis of whether, with implementation of the proposed Federal 
action, the affected critical habitat would continue to serve its 
intended conservation role for the species.
    If a species is listed or critical habitat is designated, section 
7(a)(2) of the Act requires Federal agencies to insure that activities 
they authorize, fund, or carry out are not likely to jeopardize the 
continued existence of such a species or to destroy or adversely modify 
its critical habitat. If a Federal action may affect a listed species 
or its critical habitat, the responsible Federal agency (action agency) 
must enter into consultation with us. As a result of section 7 
consultation, we document compliance with the requirements of section 
7(a)(2) through our issuance of:
    (1) A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    (2) A biological opinion for Federal actions that may affect, or 
are likely to adversely affect, listed species or critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species and/or 
destroy or adversely modify critical habitat, we provide reasonable and 
prudent alternatives to the project, if any are identifiable, that 
would avoid the likelihood of jeopardy and/or destruction or adverse 
modification of critical habitat. We define ``reasonable and prudent 
alternatives'' (at 50 CFR 402.02) as alternative actions identified 
during consultation that:
    (1) Can be implemented in a manner consistent with the intended 
purpose of the action;
    (2) Can be implemented consistent with the scope of the Federal 
agency's legal authority and jurisdiction;
    (3) Are economically and technologically feasible; and
    (4) Would, in the Director's opinion, avoid the likelihood of 
jeopardizing the continued existence of the listed species and/or avoid 
the likelihood of destroying or adversely modifying critical habitat.
    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 require Federal agencies to reinitiate 
consultation on previously reviewed actions in instances where we have 
listed a new species or subsequently designated critical habitat that 
may be affected and the Federal agency has retained discretionary 
involvement or control over the action (or the agency's discretionary 
involvement or control is authorized by law). Consequently, Federal 
agencies sometimes may need to request reinitiation of consultation 
with us on actions for which formal consultation has been completed, if 
those actions with discretionary involvement or control may affect 
subsequently listed species or designated critical habitat.
    Federal activities that may affect the Tumbling Cave snail or its 
designated critical habitat require section 7 consultation under the 
Act. Activities on State, Tribal, local, or private lands requiring a 
Federal permit (such as a permit from the U.S. Army Corps of Engineers 
under section 404 of the Clean Water Act (33 U.S.C. 1251 et seq.) or a 
permit from the Service under section 10 of the Act) or involving some 
other Federal action (such as funding from the Federal Highway 
Administration, Federal Aviation Administration, or the Federal 
Emergency Management Agency) are subject to the section 7(a)(2) 
consultation process. Federal actions not affecting listed species or 
critical habitat, and actions on State, Tribal, local, or private lands 
that are not

[[Page 37671]]

Federally funded or authorized, do not require section 7 consultations.

Application of the ``Adverse Modification'' Standard

    The key factor related to the adverse modification determination is 
whether, with implementation of the proposed Federal action, the 
affected critical habitat would continue to serve its intended 
conservation role for the species. Activities that may destroy or 
adversely modify critical habitat are those that alter the physical and 
biological features to an extent that appreciably reduces the 
conservation value of critical habitat for the Tumbling Creek 
cavesnail.
    Section 4(b)(8) of the Act requires us to briefly evaluate and 
describe, in any proposed or final regulation that designates critical 
habitat, activities involving a Federal action that may destroy or 
adversely modify such habitat, or that may be affected by such 
designation.
    Activities that may affect critical habitat, when carried out, 
funded, or authorized by a Federal agency, should result in 
consultation for the Tumbling Creek cavesnail. These activities 
include, but are not limited to:
    (1) Actions that would cause an increase in sedimentation to areas 
of Tumbling Creek, its tributaries, and associated springs occupied by 
the cavesnail. Such activities could include, but are not limited to, 
alteration or maintenance of pool levels on Bull Shoals Reservoir that 
causes backwater flooding of occupied habitat, or any discharge of fill 
materials. Such activities occurring within the recharge area of 
Tumbling Creek Cave may also impact the designated critical habitat. 
These activities could eliminate or reduce habitats necessary for the 
growth and reproduction of the species by causing excessive 
sedimentation and burial of the species or their habitats or eliminate 
interstitial spaces needed by cavesnails.
    (2) Actions that would significantly alter the existing flow regime 
of Tumbling Creek, its tributaries, and associated springs occupied by 
the cavesnail. Such activities could include, but are not limited to, 
alteration or maintenance of pool levels on Bull Shoals Reservoir that 
significantly reduces the movement of water through occupied cavesnail 
habitat. Such activities occurring within the recharge area of Tumbling 
Creek Cave may also impact the designated critical habitat.
    (3) Actions that would significantly alter water chemistry or water 
quality (for example, changes to temperature or pH, introduced 
contaminants, excess nutrients) in Tumbling Creek, its tributaries, and 
associated springs. Such activities could include, but are not limited 
to, the release of chemicals, biological pollutants, or heated 
effluents that are then introduced into Tumbling Creek, its 
tributaries, and associated spring occupied by the cavesnail through 
backwater flooding. Such activities occurring within the recharge area 
of Tumbling Creek Cave may also impact the designated critical habitat. 
These activities could alter water conditions that are beyond the 
tolerances of the species and result in direct or cumulative adverse 
effects on the species and its life cycle. These activities could 
eliminate or reduce habitats necessary for the growth and reproduction 
of the species by causing eutrophication, leading to excessive 
filamentous algal growth. Excessive filamentous algal growth can cause 
extreme decreases in nighttime dissolved oxygen levels through 
vegetation respiration, and cover the bottom substrates and the 
interstitial spaces needed by cavesnails.
    (4) Actions that could accidentally introduce nonnative species 
into Tumbling Creek, its tributaries, and associated springs occupied 
by the cavesnail via backwater flooding from Bull Shoals Reservoir. 
Such activities occurring within the recharge area of Tumbling Creek 
Cave may also impact the designated critical habitat. These activities 
could introduce a potential predator or outcompeting aquatic 
invertebrate (for example, another species of cavesnail or troglobitic 
invertebrate) or aquatic parasite.
    (5) Actions that could significantly alter the prey base of bats. 
Energy input from bat guano is essential to the Tumbling Creek 
cavesnail, such that adverse impacts to gray bat populations in 
Tumbling Creek Cave could indirectly impact the cavesnail. Such 
activities could include, but are not limited to, alteration or 
maintenance of pool levels on Bull Shoals Reservoir that significantly 
reduces the life cycles of the aquatic insects that are needed by gray 
bats for food and the potential use of insecticides for mosquito 
control.

Exemptions

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

    The Sikes Act Improvement Act of 1997 (Sikes Act) (16 U.S.C. 670a) 
required each military installation that includes land and water 
suitable for the conservation and management of natural resources to 
complete an integrated natural resource management plan (INRMP) by 
November 17, 2001. An INRMP integrates implementation of the military 
mission of the installation with stewardship of the natural resources 
found on the base. Each INRMP includes:
    (1) An assessment of the ecological needs on the installation, 
including the need to provide for the conservation of listed species;
    (2) A statement of goals and priorities;
    (3) A detailed description of management actions to be implemented 
to provide for these ecological needs; and
    (4) A monitoring and adaptive management plan.
    Among other things, each INRMP must, to the extent appropriate and 
applicable, provide for fish and wildlife management; fish and wildlife 
habitat enhancement or modification; wetland protection, enhancement, 
and restoration where necessary to support fish and wildlife; and 
enforcement of applicable natural resource laws.
    The National Defense Authorization Act for Fiscal Year 2004 (Pub. 
L. 108-136) amended the Act to limit areas eligible for designation as 
critical habitat. Specifically, section 4(a)(3)(B)(i) of the Act (16 
U.S.C. 1533(a)(3)(B)(i)) now provides: ``The Secretary shall not 
designate as critical habitat any lands or other geographical areas 
owned or controlled by the Department of Defense, or designated for its 
use, that are subject to an integrated natural resources management 
plan prepared under section 101 of the Sikes Act (16 U.S.C. 670a), if 
the Secretary determines in writing that such plan provides a benefit 
to the species for which critical habitat is proposed for 
designation.''
    There are no Department of Defense lands within the critical 
habitat designation for the Tumbling Creek cavesnail. Therefore, we are 
not exempting any lands owned or managed by the Department of Defense 
from this designation of critical habitat for the Tumbling Creek 
cavesnail pursuant to section 4(a)(3)(B)(i) of the Act.

Exclusions

Application of Section 4(b)(2) of the Act

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

[[Page 37672]]

and commercial data available, that the failure to designate such area 
as critical habitat will result in the extinction of the species. In 
making that determination, the statute on its face, as well as the 
legislative history, are clear that the Secretary has broad discretion 
regarding which factor(s) to use and how much weight to give to any 
factor.
    Under section 4(b)(2) of the Act, we may exclude an area from 
designated critical habitat based on economic impacts, impacts on 
national security, or any other relevant impacts. In considering 
whether to exclude a particular area from the designation, we identify 
the benefits of including the area in the designation, identify the 
benefits of excluding the area from the designation, and evaluate 
whether the benefits of exclusion outweigh the benefits of inclusion. 
If the analysis indicates that the benefits of exclusion outweigh the 
benefits of inclusion, the Secretary may exercise his discretion to 
exclude the area only if such exclusion would not result in the 
extinction of the species.
Exclusions Based on Economic Impacts
    Under section 4(b)(2) of the Act, we consider the economic impacts 
of specifying any particular area as critical habitat. In order to 
consider economic impacts, we prepared a draft economic analysis of the 
proposed critical habitat designation and related factors (Industrial 
Economics Incorporated 2010). The draft analysis, dated December 6, 
2010, was made available for public review from January 12, 2011, 
through February 11, 2011 (76 FR 2076). Following the close of the 
comment period, a final analysis, dated March 11, 2011, of the 
potential economic effects of the designation was developed, taking 
into consideration the public comments and any new information 
(Industrial Economics Incorporated 2011).
    The intent of the final economic analysis (FEA) is to quantify the 
economic impacts of all potential conservation efforts for the Tumbling 
Creek cavesnail; some of these costs will likely be incurred regardless 
of whether we designate critical habitat (baseline). The economic 
impact of the final critical habitat designation is analyzed by 
comparing scenarios both ``with critical habitat'' and ``without 
critical habitat.'' The ``without critical habitat'' scenario 
represents the baseline for the analysis, considering protections 
already in place for the species (e.g., under the Federal listing and 
other Federal, State, and local regulations). The baseline, therefore, 
represents the costs incurred regardless of whether critical habitat is 
designated. The ``with critical habitat'' scenario describes the 
incremental impacts associated specifically with the designation of 
critical habitat for the species. The incremental conservation efforts 
and associated impacts are those not expected to occur absent the 
designation of critical habitat for the species. In other words, the 
incremental costs are those attributable solely to the designation of 
critical habitat above and beyond the baseline costs; these are the 
costs we consider in the final designation of critical habitat. The 
analysis looks retrospectively at baseline impacts incurred since the 
species was listed, and forecasts both baseline and incremental impacts 
likely to occur with the designation of critical habitat.
    The FEA also addresses how potential economic impacts are likely to 
be distributed, including an assessment of any local or regional 
impacts of habitat conservation and the potential effects of 
conservation activities on government agencies, private businesses, and 
individuals. The FEA measures lost economic efficiency as