[Federal Register: December 15, 2009 (Volume 74, Number 239)]
[Proposed Rules]
[Page 66260-66271]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15de09-23]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R2-ES-2009-0076; 92210-1111-0000 B2]
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
Petitions To List Nine Species of Mussels From Texas as Threatened or
Endangered With Critical Habitat
AGENCY: Fish and Wildlife Service, Interior.
[[Page 66261]]
ACTION: Notice of petition finding and initiation of status review.
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SUMMARY: We, the U.S. Fish and Wildlife Service, announce a 90-day
finding on two petitions to list nine species of freshwater mussels,
the Texas fatmucket (Lampsilis bracteata), Texas heelsplitter
(Potamilus amphichaenus), Salina mucket (Potamilus metnecktayi), golden
orb (Quadrula aurea), smooth pimpleback (Quadrula houstonensis), Texas
pimpleback (Quadrula petrina), false spike (Quincuncina mitchelli),
Mexican fawnsfoot (Truncilla cognata), and Texas fawnsfoot (Truncilla
macrodon), as threatened or endangered under the Endangered Species Act
of 1973, as amended (Act) and designate critical habitat. Based on our
review, we find that the petitions present substantial scientific or
commercial information indicating that listing these species may be
warranted. Therefore, with the publication of this notice, we are
initiating a status review of the nine species of mussels to determine
if listing them is warranted. To ensure that the status review is
comprehensive, we are soliciting scientific and commercial data and
other information regarding these species. At the conclusion of this
review, we will issue a 12-month finding on the petitions, which will
address whether the petitioned actions are warranted, as provided in
section 4(b)(3)(B) of the Act. We will make a determination on critical
habitat for these species if, and when, we initiate a listing action.
DATES: To allow us adequate time to conduct this review, we request
that we receive information on or before February 16, 2010. After this
date, you must submit information directly to the Field Office (see FOR
FURTHER INFORMATION CONTACT section below). Please note that we may not
be able to address or incorporate information that we receive after the
above requested date.
ADDRESSES: You may submit information by one of the following methods:
Federal rulemaking Portal: http://www.regulations.gov.
Follow the instructions for submitting comments.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: FWS-R2-ES-2009-0076; Division of Policy and Directives
Management; U.S. Fish and Wildlife Service; 4401 Fairfax Drive, Suite
222; Arlington, VA 22203.
We will post all information received on http://
www.regulations.gov. This generally means that we will post any
personal information you provide us (see the Information Solicited
section below for more details).
FOR FURTHER INFORMATION CONTACT: Stephen D. Parris, Field Supervisor,
Clear Lake Ecological Services Field Office, 17629 El Camino Real, Ste.
211, Houston, TX 77058; telephone 281-286-8282, extension 230. If you
use a telecommunications device for the deaf (TDD), call the Federal
Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Information Solicited
When we make a finding that a petition presents substantial
information indicating that listing a species may be warranted, we are
required to promptly review the status of the species (status review).
For the status review to be complete and based on the best available
scientific and commercial information, we request information on the
nine species of mussels (Texas fatmucket, Texas heelsplitter, Salina
mucket, golden orb, smooth pimpleback, Texas pimpleback, false spike,
Mexican fawnsfoot, and Texas fawnsfoot). We request information from
governmental agencies, Native American Tribes, the scientific
community, industry, and any other interested parties concerning the
status of the nine species of mussels. We seek information for each of
the nine species regarding:
(1) The species' biology, range, and population trends, including:
(a) Habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns;
(d) Historical and current population levels, and current and
projected trends; and
(e) Past and ongoing conservation measures for the species or its
habitat.
(2) The factors that are the basis for making a listing
determination for a species under section 4(a) of the Act, which are:
(a) The present or threatened destruction, modification, or
curtailment of the species' 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 their continued
existence.
(3) Information about any ongoing conservation measures for, or
threats to, the species and their habitats.
Please include sufficient information with your submission (such as
full references) to allow us to verify any scientific or commercial
information you include.
If, after the status review, we determine that listing any of the
nine species of mussels under the Act is warranted, we will propose
critical habitat (see definition in section 3(5)(A) of the Act), in
accordance with section 4 of the Act, to the maximum extent prudent and
determinable at the time we would propose to list the species.
Therefore, within the geographical range currently occupied by the nine
species of mussels, we also request data and information on:
(1) What may constitute physical or biological features essential
to the conservation of the species,
(2) Where these features are currently found, and
(3) Whether any of these features may require special management
considerations or protection.
In addition, we request data and information on specific areas
outside the geographical area occupied by the species that are
essential to the conservation of the species. Please provide specific
comments and information as to what, if any, critical habitat you think
we should propose for designation if any of the nine species of mussels
are proposed for listing, and why such habitat meets the requirements
of section 4 of the Act.
Submissions merely stating support or opposition to the action
under consideration without providing supporting information, although
noted, will not be considered in making a determination. Section
4(b)(1)(A) of the Act directs that determinations as to whether any
species is an endangered or threatened species must be made solely on
the basis of the best scientific and commercial data available.
You may submit your information concerning this status review by
one of the methods listed in the ADDRESSES section. We will not
consider submissions sent by e-mail or fax or to an address not listed
in the ADDRESSES section.
If you submit information via http://www.regulations.gov, your
entire submission--including any personal identifying information--will
be posted on the website. If you submit a hardcopy that includes
personal identifying information, you may request at the top of your
document that we withhold this personal identifying information from
public review. However, we cannot guarantee that we will be able to do
so. We will post all hardcopy submissions on http://
www.regulations.gov.
[[Page 66262]]
Information and supporting documentation that we received and used
in preparing this finding, will be available for public inspection at
http://www. regulations.gov, or by appointment, during normal business
hours, at the U.S. Fish and Wildlife Service, Clear Lake Ecological
Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Background
Section 4(b)(3)(A) of the Act requires that we make a finding on
whether a petition to list, delist, or reclassify a species presents
substantial scientific or commercial information indicating that the
petitioned action may be warranted. We are to base this finding on
information provided in the petition, supporting information submitted
with the petition, and information otherwise available in our files. To
the maximum extent practicable, we are to make this finding within 90
days of our receipt of the petition and publish our notice of this
finding promptly in the Federal Register.
Our standard for substantial scientific or commercial information
within the Code of Federal Regulations (CFR) with regard to a 90-day
petition finding is ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the petition
may be warranted'' (50 CFR 424.14(b)). If we find that substantial
scientific or commercial information was presented, we are required to
commence a review of the status of the species, which is subsequently
summarized in our 12-month finding.
Petition History
On June 25, 2007, we received a petition dated June 18, 2007, from
Forest Guardians (now WildEarth Guardians) requesting that the Service:
(1) Evaluate all full species in our Southwest Region ranked as G1 or
G1G2 by the organization NatureServe, except those that are currently
listed, proposed for listing, or candidates for listing; and (2) list
each G1 or G1G2 species as either endangered or threatened with
critical habitat. The petitioned group of species included the Texas
fatmucket, Texas heelsplitter, Salina mucket, and golden orb. The
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2007) into the
petition. The information presented by NatureServe is considered to be
a reputable source of information with respect to taxonomy and
distribution. However, NatureServe indicates on their website that
information in their database is not intended for determining whether
species are warranted for listing under the Act. Where NatureServe
presented assertions without supporting references that allow us to
verify their statements, we found that the information presented by
NatureServe was limited in its usefulness for this process. The
petition clearly identified itself as such and included the
identification information required at 50 CFR 424.14(a). We sent a
letter dated July 11, 2007, to the petitioner acknowledging receipt of
the petition and stating that the petition was under review by staff in
our Southwest Regional Office.
On June 18, 2008, we received a petition from WildEarth Guardians,
dated June 12, 2008, to emergency list 32 species, including the Salina
mucket, under the Administrative Procedure Act (APA) (5 U.S.C.
Subchapter II) and the Act. In a letter dated July 22, 2008, we stated
that the information provided in both the 2007 and 2008 petitions and
in our files did not indicate that emergency listing of any of the
petitioned species was warranted. That letter concluded our evaluation
of the emergency aspect of the 2008 petition.
On October 15, 2008, we received a petition dated October 9, 2008,
from WildEarth Guardians requesting that the Service list six species
of freshwater mussels, the smooth pimpleback, Texas pimpleback, false
spike, Mexican fawnsfoot, Texas fawnsfoot, and southern hickorynut, as
either endangered or threatened throughout their historic ranges within
the United States and internationally. The petitioner also requested
the designation of critical habitat for each of the petitioned mussel
species. The petition clearly identified itself as such and included
the identification information required at 50 CFR 424.14(a). In
addition to other information cited in the petition, the petition
incorporates all analyses, references, and documentation provided by
NatureServe in its online database at http://www.natureserve.org/
(hereafter cited as NatureServe 2009) into the petition. To clarify,
for the first four species addressed in this finding (Texas fatmucket,
Texas heelsplitter, Salina mucket, and golden orb), we referenced the
species profiles retrieved from the NatureServe online database in
2007. For the following five species (smooth pimpleback, Texas
pimpleback, false spike, Mexican fawnsfoot, and Texas fawnsfoot), we
referenced the species profiles retrieved from the NatureServe online
database in 2009. In a November 26, 2008, letter to the petitioner, we
acknowledged receipt of the petition and stated that the petition for
the six mussel species was under review by staff in our Southwest
(Region 2) and Southeast (Region 4) Regional Offices. This finding
addresses 5 of the 6 petitioned species that occur within Region 2:
smooth pimpleback, Texas pimpleback, false spike, Mexican fawnsfoot,
and Texas fawnsfoot. Region 4 is addressing the southern hickorynut in
a separate finding. In total, this 90-day finding includes nine mussel
species; four species (Texas fatmucket, Texas heelsplitter, Salina
mucket, and golden orb) are included from the June 18, 2007, petition,
and five species (smooth pimpleback, Texas pimpleback, false spike,
Mexican fawnsfoot, and Texas fawnsfoot) from the October 9, 2008,
petition.
Previous Federal Actions
There are no previous Federal actions or previous determinations
for the Texas fatmucket, Salina mucket, golden orb, smooth pimpleback,
Texas pimpleback and Texas fawnsfoot. However, the Texas heelsplitter,
the false spike, Salina mucket (listed as Disconaias salinasensis), and
the Mexican fawnsfoot were listed as Category 2 candidate species in
the 1989 Animal Notice of Review (published January 6, 1989, at 54 FR
554) and again in the 1991 and 1994 candidate species lists (56 FR
58804 and 59 FR 58982, respectively). Category 2 candidate species
included taxa for which information in the Service's possession
indicated that a proposed listing rule was possibly appropriate, but we
did not have sufficient data available on biological vulnerability and
threats to support a proposed rule.
In 1996, the Service changed its definition of candidate species
(see 61 FR 7596). Species that had been listed as Category 1 species
remained on the candidate list and those that were listed as Category 2
species were dropped from the candidate list. Therefore, the Texas
heelsplitter, the false spike, Salina mucket, and the Mexican fawnsfoot
have not been on the candidate species list since 1996. There are no
other previous Federal actions for these species.
Species Information
All of the nine species are freshwater mussels in the family
Unionidae, and all are known to occur in Texas (Howells 2007). Mussels
in the family Unionidae are generally referred to as unionids, and we
use that term in this finding. Freshwater mussels are bottom-dwelling
and burrow into the substrate to maintain position on the stream
bottom. Some mussel species require free-flowing streams, while other
species
[[Page 66263]]
prefer, or are tolerant of, lentic (lake or pond) habitat. All
freshwater mussels are filter-feeders, collecting algae, detritus, and
bacteria from the water as it passes across the gills. Excessive
amounts of suspended sediments can interfere with a mussel's ability to
efficiently filter feed.
Unionid reproduction requires separate male and female individuals.
Fertilization takes place when a male discharges sperm into the water
column and the female intakes the water-born sperm through siphon tubes
during normal feeding and respiration (Howells et al. 1996, p. 9).
Fertilized eggs are retained in the female's brood pouch (Howells et
al. 1996, p. 9). The larvae, called glochidia, are retained in the
female brood pouch until released, then live temporarily as obligate
parasites (cannot live independently of its host) on a suitable host
fish before transforming into bottom-dwelling juveniles (Howells et al.
1996, p. 9). If the glochidia do not find a suitable host fish, they
die.
Texas fatmucket
Gould described the Texas fatmucket in 1855 (http://www.
natureserve.org/explorer/; accessed July 2, 2007; hereafter cited as
NatureServe 2007). The shell is tan to brown, is rhomboidal to oval in
shape, and reaches 9 centimeters (cm) (3.5 inches (in)) in length
(NatureServe 2007). The Texas fatmucket is historically known to occur
in the Colorado, Guadalupe, and San Antonio river systems in Texas
(Howells et al. 1996, p. 61). It is currently known from two
tributaries of the Colorado River, the Llano River, upper San Saba
River, and the upper Guadalupe River (Howells 2006, p. 97). This
species occurs in streams and smaller rivers where water depths are
less than 1 meter (m) (3.3 feet (ft)) and lives in substrates of sand,
mud, and gravel (NatureServe 2007). The glochidial host fish include
bluegill (Lepomis macrochirus) and green sunfish (L. cyanellus)
(Howells et al. 1996, p. 62).
Texas heelsplitter
Frierson described the Texas heelsplitter in 1898 (NatureServe
2007). The shell is tan to brown, is elongated, and 17.7 cm (7 in) in
length (Howells et al. 1996, p. 95). The Texas heelsplitter
historically and currently is known to occur in the Neches River, the
lower-central Trinity River, and the upper Sabine River in Texas
(Howells 2006, p. 98). This species inhabits flowing waters, preferring
mud or sand substrates in small to medium rivers, but it can also be
found in reservoirs (NatureServe 2007). The glochidial host fish for
the Texas heelsplitter are unknown (Howells et al. 1996. p. 96).
Salina mucket
Johnson described the Salina mucket in 1998 (NatureServe 2007).
Salina mucket has undergone taxonomic changes since the mussel's
original listing on the 1989 Animal Notice of Review. We intend to
investigate these taxonomic revisions further during the status review.
The shell is tan to dark brown or black, is oval, and reaches a length
of 10.5 cm (4.1 in) (Howells et al. 1996, pp. 103-104). The Salina
mucket historically occurred in the Rio Grande as far north and west as
New Mexico and as far south as northern Mexico (Howells et al. 1996, p.
103). It currently is known from the Rio Grande in Texas from the Big
Bend region in Brewster County downstream to below the Falcon Dam in
Starr County (NatureServe 2007), although there is no mention of its
occurrence in Falcon Reservoir. The species inhabits flowing streams
and rivers with sand and gravel substrates (NatureServe 2007). The
glochidial host fish for the Salina mucket are unknown (Howells et al.
1996, p. 104).
Golden orb
Lea described the golden orb in 1859 (NatureServe 2007). The shell
varies from tan, reddish-brown, orange-brown, to gray-brown; is
somewhat rectangular to broadly elliptical in shape; and reaches an
overall length of 7.7 cm (3.0 in) (Howells et al. 1996, p. 108). The
golden orb historically occurred in the Guadalupe, San Antonio,
Colorado, and Nueces-Frio river systems. Currently, it is known from
the upper and central Guadalupe River, lower San Marcos River, and Lake
Corpus Christi in the lower Nueces River drainage (Howells 2006, p.
98). This species appears to be restricted to flowing waters with sand,
gravel, and cobble bottoms at depths of a few cm (few in) to over 3 m
(9.8 ft). The glochidial host fish for the golden orb are unknown
(Howellset al. 1996, p. 109).
Smooth pimpleback
Lea described the smooth pimpleback in 1859 (http://
www.natureserve.org/explorer/; accessed February 12-13, 2009; hereafter
cited as NatureServe 2009). The shell is dark brown to black, round in
shape, and generally smooth, but it may have a few small pimples
(bumps) and can reach a length of 6.5 cm (2.5 in) (NatureServe 2009).
The smooth pimpleback historically occurred in the Brazos and Colorado
River systems of central Texas (Howells 2006, p. 98). Currently, it is
known from the central Brazos, central Leon, central Little Brazos, and
Navasota rivers in the Brazos River system, and from the central
Colorado River (Howells 2007, slide 13). It prefers small-to moderate-
sized streams and rivers, as well as moderate-sized reservoirs, and it
is found in mixed-mud, sand, and fine gravel substrate (NatureServe
2009). The glochidial host fish for the smooth pimpleback are unknown
(NatureServe 2009).
Texas pimpleback
Gould described the Texas pimpleback in 1855 (NatureServe 2009).
The shell is glossy and tan to brown in color, with some individuals
displaying distinctive green and yellow markings (NatureServe 2009).
The Texas pimpleback historically occurred in the upper and central
Brazos, Colorado, and Guadalupe-San Antonio river systems (Howells
2006, p. 99); currently, it is known from two tributaries of the
Colorado River, the lower Concho and upper San Saba rivers, as well as
the upper San Marcos River (Howells 2007, slide 13). Texas pimplebacks
generally inhabit rivers with low flow rates with mud, gravel, and sand
substrates (NatureServe 2009). The glochidial host fish for the Texas
pimpleback are unknown (NatureServe 2009).
False spike
Simpson described the false spike in 1895 (NatureServe 2009). The
shell is tawny-brown to dark brown or black, oval to round in shape,
and up to 13.2 cm (5.2 in) in length (Howells et al. 1996, p. 128).
According to information in the petition, it has parallel, ripple-like
ridges in the posterior and central portion of the shell. The false
spike occurred historically in the Brazos, Colorado, and Guadalupe
river systems in central Texas and in the Rio Grande system in New
Mexico, Texas, and Mexico (NatureServe 2009). The only known extant
population occurs in the lower San Marcos River, a tributary to the
Guadalupe River system (Howells 2007, slide 16). False spike has been
found in medium to large rivers with substrates varying from mixed mud,
sand, and gravel, to cobble (NatureServe 2009). The glochidial host
fish for the false spike are unknown (NatureServe 2009).
Mexican fawnsfoot
Lea described the Mexican fawnsfoot in 1860 (NatureServe 2009). The
shell is yellow- to gray-green, elliptical in shape, and up to 4.4 cm
(1.7 in) in length (NatureServe 2009). The Mexican fawnsfoot
historically occurred in a large section of the Rio Grande system,
including the lower Pecos River near
[[Page 66264]]
Del Rio, Texas, and through the Rio Salado of Nuevo Leon and
Tamaulipas, Mexico (NatureServe 2009). Now, the Mexican fawnsfoot is
known to inhabit only a small section of the lower Rio Grande in
Laredo, Texas (NatureServe 2009). Habitat preferences for the Mexican
fawnsfoot are largely unknown because environmental modifications of
the Rio Grande make it difficult to define clearly the habitats that
are required or preferred by the Mexican fawnsfoot (NatureServe 2009).
This species has not been reported from reservoirs, suggesting a
preference for flowing streams and rivers with sand or gravel bottoms
(NatureServe 2009). The glochidial host fish for the Mexican fawnsfoot
are unknown (NatureServe 2009).
Texas fawnsfoot
Lea described the Texas fawnsfoot in 1850 (NatureServe 2009). Shell
color varies from gray-green, greenish-brown, orange brown to dark
brown, often with a pattern of broken rays (NatureServe 2009). It is
oval in shape and reaches a length of 5.5 cm (2.2 in) (NatureServe
2009). The Texas fawnsfoot historically occurred in the Brazos and
Colorado river systems. Until 2009, the only known surviving population
was in the Brazos River system (NatureServe 2009). We are aware of a
recently discovered population estimated to be approximately 3,000
individuals in the upper portion of the Colorado River (Burlakova 2009,
pers. comm.; Leggett 2009). We intend to investigate the report more
thoroughly in our status review for the species. The species appears to
prefer flowing rivers and large streams with sand, gravel, and mixed
muddy substrates (NatureServe 2009). Living specimens have not been
documented in reservoirs, but in the past have been found alive in
flowing rice irrigation canals (NatureServe 2009). The glochidial host
fish for the Texas fawnsfoot are unknown (NatureServe 2009).
Evaluation of Information for This Finding
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
at 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.
In making this 90-day finding, we evaluated whether information
regarding the nine species of mussels, as presented in the petitions
and other information available in our files, is substantial, thereby
indicating that the petitioned action may be warranted. Our evaluation
of this information is presented below. The information discussed below
was presented by the petitioner, unless otherwise noted.
Texas fatmucket
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petition incorporates all analyses, references, and
documentation provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2007) into the
petition. NatureServe (2007) claims that poor land management
activities in the past century have resulted in the loss and
modification of habitat, and the reduction in abundance, of the Texas
fatmucket. NatureServe (2007) identifies intense overgrazing as a land
management activity that has been harmful to the Texas fatmucket;
however, no further discussion or reference is provided.
Five of the six known populations, all in central Texas, are
threatened by periodic flooding and possibly dewatering (NatureServe
2007). Howells et al. (2003, p. 5), cited in NatureServe (2007), report
that the population of a Colorado River tributary in Runnels County
experienced extensive, if not complete, dewatering in 1999 and 2000,
then flood-scouring in 2000 and 2001. No living or recently dead
specimens could be found in a 2001 survey, and the stream had suffered
major alterations in form and structure. A second population in a
Concho River tributary in Tom Green County is presumed extirpated. The
small stream reportedly dried completely in 1999 and 2000, and no
specimens have been reported from the stream from subsequent surveys
(Howells et al. 2003, p. 5). A third population in the San Saba River
in Menard County experienced reduced water levels in the late 1990s
followed by flooding in 2000. Based on post-flood examination of river
and bank structure, mussels in the San Saba are thought to still
persist (Howells et al. 2003, p. 5). A fourth population in the
Guadalupe River in Kerr County is presumed to have been eliminated in
1998, when river levels were drawn down to build a footbridge (Howells
et al. 2003, p. 5). A fifth population in a Pedernales River tributary
in Gillespie County was discovered when flood waters stranded specimens
in 2002 (Howells et al. 2003, p. 5). This area had been surveyed prior
to the flood, yielding no living or recently dead specimens, and the
recent collection of a single living specimen at this site suggests
that the population is limited (Howells et al. 2003, p. 5).
Evaluation of Information
In our evaluation of the petition, we find that the petitioner
provides substantial information indicating that listing the Texas
fatmucket may be warranted due to present or threatened destruction,
modification, or curtailment of the species' habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the Texas fatmucket
due to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Texas fatmucket
due to disease or predation may be warranted.
D. Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
NatureServe (2007) states that few occurrences of Texas fatmucket
are appropriately protected and managed, and that only one Texas
fatmucket population is currently in an area designated as a no-harvest
mussel sanctuary, meaning commercial harvest is not permitted.
NatureServe (2007) cites Howells et al. (1997, p.126) in stating that
no-harvest sanctuary designations alone afford little protection where
environmental disturbances of terrestrial habitats result in subsequent
loss of aquatic habitats. NatureServe (2007) states that the Texas
fatmucket is not a State or federally protected species.
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the Texas fatmucket, we find the petition does not provide substantial
[[Page 66265]]
information indicating that listing the species due to inadequacy of
existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
The petitioner does not address other natural and manmade factors,
and we have no information in our files indicating that listing the
Texas fatmucket due to other natural and manmade factors may be
warranted.
Texas heelsplitter
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petition incorporates all analyses, references, and
documentation provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2007) into the
petition. NatureServe (2007) claims that Texas heelsplitter habitat is
threatened by siltation. NatureServe (2007) cites Neck and Howells
(1995, cited in NatureServe 2007 as Neck and Howells 1994) in stating
that sand and silt deposition create undesirable mussel habitat and
cover existing mussel beds. In their status survey for the species,
Neck and Howells (1995, p. 14) report that silt and mud deposition in
the B.A. Steinhagen Reservoir, which is occupied by the Texas
heelsplitter, caused many areas of the reservoir to become shallow and
filled some bays in the reservoir with silt. These conditions do not
support habitation by Texas heelsplitter.
NatureServe (2007) identifies pollution as a threat to Texas
heelsplitter habitat. Neck and Howells (1995, p. 15) state that
increases in acidity, runoff, effluents from wood pulp and paper mills,
human-caused nutrient enrichment, tar and oil, and increased silt loads
due to land clearing are shown to have damaging effects on mussel
habitat. Pollutants of these types have been reported in the upper
Trinity River, in Pine Island Bayou (a tributary to the Neches River),
and in the lower Neches River, all of which are situated within the
range of the Texas heelsplitter (Neck and Howells 1995, p. 15). They
conclude that the anticipated urban expansion of cities in Texas will
likely amplify this threat in the foreseeable future (Neck and Howells
1995, p. 14).
Neck and Howells (1995, pp. 15-16), which is cited in NatureServe
(2007), indicate that the Texas heelsplitter is negatively impacted by
aquatic plants, including water hyacinth (Eichhornia crassipes) and
hydrilla (Hydrilla verticillata), which have invaded reservoirs
occupied by the Texas heelsplitter. Unmanaged, these plants can
eliminate mussel habitat; however, the techniques currently employed
for the management of these species, including mechanical removal,
herbicides, and water drawdowns, also negatively affect mussel
populations (Neck and Howells 1995, pp. 15-16). NatureServe (2007)
identifies fluctuating water levels associated with water drawdowns at
reservoirs as a current threat for the Texas heelsplitter.
Evaluation of Information
Information in our files supports the claims made in the petition
regarding the present and future threat of fluctuating water levels to
the Texas heelsplitter and its habitat. Howells (2006, p. 32) indicates
that the Texas heelsplitter is negatively affected by water drawdowns
at B.A. Steinhagen Reservoir, part of the Neches River drainage. These
drawdowns result in mussel mortality and overall decreased mussel
abundance and diversity (Howells 2006, pp. 24-34). Since the early
1990s, the Texas Parks and Wildlife Department (TPWD) and the reservoir
operator have employed mid-winter water drawdowns to reduce aquatic
plant density through drying and cold temperatures on the reservoir
(Howells 2006, p. 32). The water level is lowered slowly to allow the
mussels to follow the receding water level, and the duration of the
drawdown is as short as possible to minimize mussel mortality; however,
repeated drawdowns in the range of the Texas heelsplitter may be
decreasing the abundance of the species (Howells 2006, p. 32).
In our evaluation of the petition and information in our files, we
find that there is substantial information indicating that listing the
Texas heelsplitter may be warranted due to the present or threatened
destruction, modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the Texas heelsplitter
due to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Texas
heelsplitter due to disease or predation may be warranted.
D. Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
NatureServe (2007) states that it is unknown whether any
occurrences of Texas heelsplitter are appropriately protected and
managed.
Evaluation of Information
We do not consider the statement by NatureServe (2007) to be a
sufficient presentation of information indicating to a reasonable
person that listing may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
The petitioner does not address other natural and manmade factors,
and we have no information in our files indicating that listing the
Texas heelsplitter due to other natural and manmade factors may be
warranted.
Salina mucket
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petition incorporates all analyses, references, and
documentation provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2007) into the
petition. NatureServe (2007) identifies poor land and water management
practices as threats to Salina mucket habitat. NatureServe (2007) cites
Howells (2003, p. 70; cited in NatureServe 2007 as Howells 2001) in
stating that the lower Rio Grande system within the range of the Salina
mucket has experienced a significant increase in human population and
urban development in the last 30 years. Land management activities
associated with increased human development include land clearing and
construction of impervious surfaces, which contribute to increased
runoff and silt loads during storms and to additional scouring and
riverbed modifications (Howells 2003, p. 66). Howells (2004b, p. 2)
states that the only known surviving Salina mucket specimens in the Rio
Grande are in areas undergoing major development and modification.
Increased water demands that are projected with continuing residential
and commercial
[[Page 66266]]
development in the range of the Salina mucket will likely compound
factors currently affecting the species (Howells 2004b, p. 2).
NatureServe (2007) identifies siltation as a threat to Salina
mucket habitat; however, no further discussion is provided. NatureServe
(2007) also identifies drought-related dewatering as a threat to Salina
mucket habitat. The Salina mucket habitat within the Rio Grande system
has been subject to periods of drought punctuated by severe storm
events, often producing scouring floods that modify the riverbed and
alter mussel habitat (Howells 2003, p. 66). Historical drought-related
dewatering likely reduced or eliminated some unionid populations in the
region, and the current decline in water flow rates constitutes an
increasing threat to the species and its habitat (Howells 2003, p. 67).
Evaluation of Information
In our evaluation of the petition, we find that the petitioner
provides substantial information indicating that listing the Salina
mucket may be warranted due to the present or threatened destruction,
modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the Salina mucket due
to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Salina mucket
due to disease or predation may be warranted.
D. Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
NatureServe (2007) states that no occurrences of Salina mucket are
appropriately protected and managed, that no Salina mucket populations
occur in State-designated no-harvest mussel sanctuaries, and that the
Salina mucket is not a State or federally protected species.
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the Salina mucket, we find the petition does not provide substantial
information indicating that listing the species due to inadequacy of
existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Information Provided in the Petition
NatureServe (2007) identifies population isolation as a threat to
the Salina mucket. Howells (2003, p. 68) indicates that the Pecos
River, a tributary of the Rio Grande, is the major source of elevated
salinity of the waters in the lower Rio Grande drainage. Natural salt
seeps and deposits are present in the area, but groundwater pumping
that has lowered the water table and reduced freshwater input, long
periods of reduced precipitation, and brines from oil and gas drilling
operations likely contribute to current high saline conditions (Howells
2003, pp. 68-69). Howells (2004b, p. 2) reports that the salinity of
the Pecos River creates a functional barrier between Salina mucket
specimens in the area, thus inhibiting opportunities for dispersal and
interbreeding. This physical separation may result in the genetic
isolation of surviving Salina mucket populations downstream of the Big
Bend in the area of Brewster County, Texas (Howells 2003, p. 69).
Evaluation of Information
In our evaluation of the petition, we find that the petition
presents substantial information indicating that listing the Salina
mucket may be warranted due to population isolation.
Golden orb
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petition incorporates all analyses, references, and
documentation provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2007) into the
petition. NatureServe (2007) identifies flooding as a threat to golden
orb habitat. Howells et al. (1997, p. 118), cited in NatureServe
(2007), report that the greatest decline in golden orb numbers appears
to have occurred in 1978 during a major hurricane and subsequent
flooding in the species' range. NatureServe (2007) asserts that this
single event appears to have reduced the species to four primary
populations, and that three of these populations in the Guadalupe River
are still subject to flood-related scouring and large water-level
fluctuations.
NatureServe (2007) identifies the effects of poor land and water
management practices as a threat to golden orb habitat; however, no
further discussion is provided. NatureServe (2007) also identifies
drought as a threat to golden orb habitat; however, no further
discussion is provided.
Evaluation of Information
The petition does not provide substantial information indicating
that listing the golden orb due to poor land and water management or to
drought may be warranted. However, information in our files from
Howells' 2006 Statewide freshwater mussel survey supports the
petitioner's claim of the species' negative response to flooding in its
habitat. Specifically, in the Guadalupe River below the Upper Guadalupe
River Authority dam, no golden orbs were found in a survey following a
1996 flood, three were found dead following a second flood in 1997,
none were found following a high water release from the dam 4 months
later, and none were found in a 2005 survey (Howells 2006, p. 71). In
our evaluation of the petition and information in our files, we
therefore find that there is substantial information indicating that
listing the golden orb may be warranted due to the present or
threatened destruction, modification, or curtailment of its habitat or
range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific, or educational purposes, and we have no
information in our files indicating that listing the golden orb due to
overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the golden orb due
to disease or predation may be warranted.
D. Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
NatureServe (2007) states that few occurrences of golden orb are
appropriately protected and managed, and that none of the inhabited
sites of the four known populations are protected. NatureServe (2007)
states that the golden orb is not a State or federally protected
species.
Evaluation of Information
We do not consider the statements by NatureServe (2007) to be a
sufficient presentation of information indicating
[[Page 66267]]
to a reasonable person that listing may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
The petitioner does not address other natural and manmade factors,
and we have no information in our files indicating that listing the
golden orb due to other natural and manmade factors may be warranted.
Smooth pimpleback
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
In addition to other information cited in the petition, the
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2009) into the
petition. The petitioner identifies increased human activity within the
species' range and associated poor land and water management practices
as a threat to smooth pimpleback habitat. NatureServe (2009) adds that
recent habitat loss continues to affect the species.
The petitioner identifies pollution as a threat to smooth
pimpleback habitat, and cites NatureServe (2009) in claiming that a
chemical dump on the Little Brazos River in 1993 eliminated many of the
mussel populations there, including the smooth pimpleback.
The petitioner cites NatureServe (2009) in asserting that drought
conditions that decreased surface water levels in the 1980s in the Leon
River range caused extensive loss of smooth pimpleback individuals. The
petitioner also cites NatureServe (2009) in asserting that scouring
floods in 1978 throughout the range of the species in central Texas
were responsible for the reduction or elimination of many mussel
populations, including the smooth pimpleback. NatureServe (2009)
clarifies that the species does not tolerate dramatic water
fluctuations, scoured bedrock substrates, or shifting sand bottoms, all
of which are associated with floods.
Evaluation of Information
Information in our files indicates that water fluctuations
unrelated to drought occur in areas occupied by smooth pimplebacks.
Howells (2006, p. 67) reports that water-level drawdowns adversely
impact Inks Lake's population of smooth pimplebacks. Lake elevation is
rapidly reduced by 3 meters (m) (9.8 ft) during biannual maintenance
and repair drawdowns (Howells 2006, p. 67). Howells (2006, p. 67)
reports that these drawdowns occur so quickly that any unionids
occupying the shallows are generally killed with each drawdown.
In our evaluation of the petition and information in our files, we
find that there is substantial information indicating that listing the
smooth pimpleback may be warranted due to the present or threatened
destruction, modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the smooth pimpleback
due to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the smooth
pimpleback due to disease or predation may be warranted.
D. Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
NatureServe (2009) states that no occurrences of smooth pimpleback
are appropriately protected and managed, and that no smooth pimpleback
populations occur in State-designated no-harvest mussel sanctuaries.
The petitioner states that the smooth pimpleback is not a State or
federally protected species (NatureServe 2009).
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the smooth pimpleback, we find the petition does not provide
substantial information indicating that listing the species due to
inadequacy of existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Information Provided in the Petition
The petitioner identifies climate change as an additional factor
affecting the species' continued existence; however, no specific
justification or reference is provided.
Evaluation of Information
The information presented on climate change is not specific to the
smooth pimpleback and no specific references were provided. The
petition does not provide substantial information indicating that
listing the species due to climate change may be warranted. We intend
to investigate this factor more thoroughly in our status review of the
species.
Texas pimpleback
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petitioner states that dewatering is a threat to the species,
but points out that some individuals survive severe stream dewatering.
Howells (2006, p. 61) reports that in the Concho River in Concho
County, low water levels and high temperatures killed large numbers of
Texas pimplebacks and other mussels in 1997, and in 1999 and early
2000. The Concho River was reduced to stagnant pools and dry bottoms.
Results from subsequent surveys indicate that Texas pimpleback
abundance was significantly reduced, presumably due to habitat
modifications that restrict mussel habitation (Howells 2006, p. 61).
The petitioner states that habitat occupied by the Texas pimpleback is
threatened by drought and flooding; however, no further discussion is
provided.
Evaluation of Information
Information in our files shows that over the 10 years from 1998 to
2007, there was zero flow measured at the stream gage at the Concho
River mussel survey site 26 percent of the days (Asquith and Heitmuller
2008, pp. 810-813, 846-853). These data suggest that dewatering may be
continuing in the Concho River.
Information in our files indicates that scouring floods and
drought-related dewatering have caused recent losses of Texas
pimpleback populations in Runnels County, Texas. No live Texas
pimpleback individuals were found during a 2005 survey in the Colorado
River drainage at either a site on the San Saba River or one on Elm
Creek where they had been found previously (Howells 2006, pp. 63-64).
These sites showed signs of extensive flood scouring during surveys
conducted throughout the 1990s and early 2000s, and overall mussel
abundance and diversity have been reduced (Howells 2006, pp. 63-64).
In our evaluation of the petition and information in our files, we
find that
[[Page 66268]]
there is substantial information indicating that listing the Texas
pimpleback may be warranted due to the present or threatened
destruction, modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Information Provided in the Petition
The petitioner states that overcollection at one site has
negatively impacted the Texas pimpleback; however, no further
discussion is provided.
Evaluation of Information
Information in our files indicates that the Texas pimpleback may be
taken by rare-shell collectors (Howells 2004a, slide 14). Howells
(2006, p. 63) reports that details released over the Internet in 2001
disclosing the location of rare mussels at the site may have been used
by rare-shell collectors to find and harvest Texas pimplebacks.
We find that the petition and information in our files presents
substantial information indicating that listing the Texas pimpleback
may be warranted due to overutilization for commercial, recreational,
scientific, or educational purposes.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Texas
pimpleback due to disease or predation may be warranted.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
In addition to other information cited in the petition, the
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2009) into the
petition. NatureServe (2009) indicates that few occurrences of Texas
pimpleback are appropriately protected and managed, and that only one
Texas pimpleback population is currently in a State-designated no-
harvest mussel sanctuary. The petitioner cites Howells et al. (1997,
p.126) in stating that no-harvest sanctuary designations alone afford
little protection where environmental disturbances of terrestrial
habitats result in subsequent loss of aquatic habitats.
Evaluation of Information
In Factor B, the petitioner and our files identify overutilization
for commercial, recreational, scientific, or educational purposes as a
potential threat to the Texas pimpleback. Here, we find that the
petitioner and information in our files provides substantial
information indicating that listing the Texas pimpleback may be
warranted due to inadequacy of existing regulatory mechanisms to
protect the species from this potential threat.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Information Provided in the Petition
The petitioner identifies climate change as an additional factor
affecting the species' continued existence; however, no specific
justification or reference is provided.
Evaluation of Information
The information presented on climate change is not specific to the
Texas pimpleback and no specific references were provided. The petition
does not provide substantial information indicating that listing the
species due to climate change may be warranted. We intend to
investigate this factor more thoroughly in our status review of the
species.
False spike
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petitioner claims that the dramatic land use modification of
the lower Rio Grande drainage over the past 100 years has negatively
affected the false spike. The petitioner further claims that continued
development and modification, including increases in human activity and
associated negative environmental impacts, may preclude future
conservation of the species.
The petitioner identifies overgrazing and increased runoff from
rains as threats to false spike habitat in central Texas. The
petitioner, citing a personal communication with R. Howells in July
2008, claims that in the mid-to late 1800s, overgrazing resulted in
loss of terrestrial vegetative cover and soils. Subsequently, when
rains fell, runoff increased, scouring riverbeds. The petitioner
references the same personal communication in stating that prior to the
1900s, the Guadalupe River never rose more than 1.8 m (6 ft), but that
6-m (20-ft) rises are now regularly observed. This has resulted in
scour of river bottoms to bedrock and cobble, which the petitioner
claims is unacceptable habitat for unionid mussels.
The petitioner identifies drought and flooding as threats to false
spike habitat. Howells (2006, p. 73) states that drought conditions in
the late 1970s, followed by major flooding events in 1978 and 1981
within the false spike's range in the San Marcos River, part of the
Guadalupe River drainage, likely had negative impacts on unionid
mussels in that area, including the false spike.
Evaluation of Information
Information in our files supports the petitioner's claim that
humans have significantly modified land use in the Rio Grande basin in
Texas and Mexico, and that this land use change may be a threat to
false spike. Howells (2003, pp. 66, 70) states that human-caused
impacts appear to be the major reason for the massive reduction in
mussel fauna and diversity there, including the apparent extinction of
the false spike. He identifies climate change; altered water flows;
impoundments; and increased nutrient, salt, and sediment pollution as
the human-caused threats responsible for the threats (Howells 2003, pp.
66-70).
The petitioner and information in our files provide substantial
information indicating that listing the false spike may be warranted
due to the present or threatened destruction, modification, or
curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the false spike due to
overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the false spike due
to disease or predation may be warranted.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
In addition to other information cited in the petition, the
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2009) into the
petition. NatureServe (2009) states that
[[Page 66269]]
no occurrences of false spike are appropriately protected and managed.
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the false spike, we find the petition does not provide substantial
information indicating that listing the species due to inadequacy of
existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Information Provided in the Petition
The petitioner identifies climate change as an additional factor
affecting the false spike's continued existence; however, no specific
justification or reference is provided.
Evaluation of Information
The information presented on climate change is not specific to the
false spike and no specific references were provided. The petition does
not provide substantial information indicating that listing the species
due to climate change may be warranted. We intend to investigate this
factor more thoroughly in our status review of the species.
Mexican fawnsfoot
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
In addition to other information cited in the petition, the
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2009) into the
petition. NatureServe (2009) identifies the effects of increased human
activity as a threat to Mexican fawnsfoot habitat. Trade and
development along the U.S. (Texas)-Mexico border have had extensive
environmental impacts on this area, which has already undergone great
ecological modification (NatureServe 2009). The petitioner cites
Howells (2004a) in stating that the only known extant population of the
Mexican fawnsfoot, located near Laredo, Texas, is threatened by impacts
from development. Additional landscape modification is anticipated,
including the proposed construction of a fence at the border (Howells
2007, slide 14). The petitioner also identifies smothering and
siltation as a threat to the Mexican fawnsfoot and its habitat;
however, no further discussion is provided. The petitioner cites
NatureServe (2009) in stating that the general fragility of the Rio
Grande aquatic ecosystem and ecological alterations to date are likely
a cause of the extreme rarity of this species.
The petitioner identifies dewatering as a threat to Mexican
fawnsfoot habitat. The petitioner cites Howells (2004b, p. 2) in
stating that all unionid assemblages in the Rio Grande basin, including
the Mexican fawnsfoot, have been subject to drought-related dewatering.
Evaluation of Information
In our evaluation of the petition, we find that the petitioner
provides substantial information indicating that listing the Mexican
fawnsfoot may be warranted due to the present or threatened
destruction, modification, or curtailment of its habitat or range.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific, or educational purposes, and we have no
information in our files indicating that listing the Mexican fawnsfoot
due to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Mexican
fawnsfoot due to disease or predation may be warranted.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
The petitioner cites NatureServe (2009) in stating that no
occurrences of Mexican fawnsfoot are appropriately protected and
managed, and that no Mexican fawnsfoot populations occur in State-
designated no-harvest mussel sanctuaries. The petitioner states that
the Mexican Fawnsfoot is not a State or federally protected species
(NatureServe 2009).
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the Mexican fawnsfoot, we find the petition does not provide
substantial information indicating that listing the species due to
inadequacy of existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Information Provided in the Petition
The petition identifies climate change as an additional factor
affecting the species' continued existence; however, no specific
justification or reference is provided.
Evaluation of Information
The information presented on climate change is not specific to the
Mexican fawnsfoot and no specific references were provided. The
petition does not provide substantial information indicating that
listing the species due to climate change may be warranted. We intend
to investigate this factor more thoroughly in our status review of the
species.
Texas fawnsfoot
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Information Provided in the Petition
The petitioner identifies aquatic habitat destruction and
modification from wide-ranging terrestrial sources as a threat to the
Texas fawnsfoot; however, these terrestrial sources are not specified
and no further discussion is provided. The petitioner also identifies
smothering and siltation as a threat to the Texas fawnsfoot and its
habitat; however, no further discussion is provided that is specific to
the species or to the rivers and streams where it is known to occur.
The petitioner identifies dewatering as a threat to Texas fawnsfoot
habitat, stating that in 2000, the Colorado River above Lake Buchanan
dried, and all mussels in that area, including the Texas fawnsfoot,
were presumed lost. The petitioner further states that because the
species is intolerant of impounded water bodies, the species would not
be able to recolonize the dewatered area from Lake Buchanan. The
petitioner also identifies scouring floods during times of intense
precipitation as a threat to Texas fawnsfoot habitat.
Evaluation of Information
In our evaluation of the petition, we find that the petitioner
provides substantial information indicating that listing the Texas
fawnsfoot may be warranted due to the present or threatened
destruction, modification, or curtailment of its habitat or range.
[[Page 66270]]
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petitioner does not address overutilization for commercial,
recreational, scientific or educational purposes, and we have no
information in our files indicating that listing the Texas fawnsfoot
due to overutilization may be warranted.
C. Disease or Predation
The petitioner does not address disease or predation, and we have
no information in our files indicating that listing the Texas fawnsfoot
due to disease or predation may be warranted.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
In addition to other information cited in the petition, the
petition incorporates all analyses, references, and documentation
provided by NatureServe in its online database at http://
www.natureserve.org/ (hereafter cited as NatureServe 2009) into the
petition. NatureServe (2009) indicates that few occurrences of Texas
fawnsfoot are appropriately protected and managed. There are two no-
harvest sanctuaries within the range of the Texas fawnsfoot; however,
the species has not been historically or recently documented at these
sites (NatureServe 2009). The petitioner states that the Texas
fawnsfoot is not a State or federally protected species (NatureServe
2009).
Evaluation of Information
Since mussel harvest was not identified as a potential threat to
the Texas fawnsfoot, we find the petition does not provide substantial
information indicating that listing the species due to inadequacy of
existing regulatory mechanisms may be warranted.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Information Provided in the Petition
The petitioner identifies climate change as an additional factor
affecting the species' continued existence; however, no specific
justification or reference is provided.
Evaluation of Information
The information presented on climate change is not specific to the
Texas fawnsfoot and no specific references were provided. The petition
does not provide substantial information indicating that listing the
species due to climate change may be warranted. We intend to
investigate this factor more thoroughly in our status review for the
species.
Finding
On the basis of our evaluation under section 4(b)(3)(A) of the Act,
we have determined that the petition presents substantial information
indicating that listing the Texas fatmucket, Texas heelsplitter, Salina
mucket, golden orb, smooth pimpleback, Texas pimpleback, false spike,
Mexican fawnsfoot, and Texas fawnsfoot throughout the entire range of
each species may be warranted.
The petitioner presents substantial information indicating that the
Texas fatmucket may be threatened by Factor A. The petitioner does not
present substantial information indicating that Factors B, C, D or E
are currently, or in the future may be, considered a threat to the
Texas fatmucket.
The petitioner presents substantial information indicating that the
Texas heelsplitter may be threatened by Factor A. The petitioner does
not present substantial information indicating that Factors B, C, D, or
E are currently, or in the future may be, considered a threat to the
Texas heelsplitter.
The petitioner presents substantial information indicating that the
Salina mucket may be threatened by Factors A and E. The petition does
not present substantial information indicating that Factors B, C, and D
are currently, or in the future may be, considered a threat to the
Salina mucket.
The petitioner presents substantial information indicating that the
golden orb may be threatened by Factor A. The petitioner does not
present substantial information indicating that Factors B, C, D, or E
are currently, or in the future may be, considered a threat to the
golden orb.
The petitioner presents substantial information indicating that the
smooth pimpleback may be threatened by Factor A. The petitioner does
not present substantial information indicating that Factors B, C, D, or
E are currently, or in the future may be, considered a threat to the
smooth pimpleback.
The petitioner presents substantial information indicating that the
Texas pimpleback may be threatened by Factors A, B, and D. The
petitioner does not present substantial information indicating that
Factors C or E are currently, or in the future may be, considered a
threat to the Texas pimpleback.
The petitioner presents substantial information indicating that the
false spike may be threatened by Factor A. The petitioner does not
present substantial information indicating that Factors B, C, D, or E
are currently, or in the future may be, considered a threat to the
false spike.
The petitioner presents substantial information indicating that the
Mexican fawnsfoot may be threatened by Factor A. The petitioner does
not present substantial information indicating that Factors B, C, D, or
E are currently, or in the future may be, considered a threat to the
Mexican fawnsfoot.
The petitioner presents substantial information indicating that the
Texas fawnsfoot may be threatened by Factor A. The petitioner does not
present substantial information indicating that Factors B, C, D, or E
are currently, or in the future may be, considered a threat to the
Texas fawnsfoot.
Based on this review and evaluation, we find that the petitions
present substantial scientific or commercial information that listing
the nine mussel species throughout the range of each species may be
warranted due to current and future threats presented in our discussion
of the five listing factors. As such, we are initiating a status review
to determine whether listing these mussels under the Act is warranted.
We will issue one or more 12-month findings as to whether any of the
petitioned actions are warranted.
The ``substantial information'' standard for a 90-day finding
differs from the Act's ``best scientific and commercial data'' standard
that applies to a status review to determine whether a petitioned
action is warranted. A 90-day finding does not constitute a status
review under the Act. In one or more 12-month findings, we will
determine whether a petitioned action is warranted after we have
completed a thorough status review of the species, which is conducted
following a substantial 90-day finding. Because the Act's standards for
90-day and 12-month findings are different, as described above, a
substantial 90-day finding does not mean that the 12-month finding will
result in a warranted finding.
The petitioner requested that we designate critical habitat for
these species. If we determine in our 12-month finding(s) that listing
the mussels is warranted, we will address the designation of critical
habitat at the time of the proposed rulemaking.
References Cited
A complete list of references cited in this finding is available on
the Internet at http://www.regulations.gov and upon request from the
Clear Lake Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
[[Page 66271]]
Author
The primary authors of this rule are the Clear Lake Ecological
Services Field Office's staff members (see FOR FURTHER INFORMATION
CONTACT).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: November 25, 2009
Daniel M. Ashe,
Acting Director, Fish and Wildlife Service
[FR Doc. E9-29698 Filed 12-14-09; 8:45 am]
BILLING CODE 4310-55-S