[Federal Register Volume 76, Number 63 (Friday, April 1, 2011)]
[Proposed Rules]
[Pages 18138-18143]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-7691]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2010-0084; [MO 92210-0-0008-B2]
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To List the Spring Pygmy Sunfish as Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of petition finding and initiation of status review.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service, announce a 90-day
finding on a petition to list the spring pygmy sunfish (Elassoma
alabamae) as endangered under the Endangered Species Act of 1973, as
amended (Act). Based on our review, we find that the petition and
information currently available in our files presents substantial
scientific or commercial information indicating that listing this
species may be warranted. Therefore, with the publication of this
notice, we are initiating a review of the status of the species to
determine if the petitioned action is warranted. To ensure this status
review is comprehensive, we are requesting scientific and commercial
data and other information regarding this species. Based on the status
review, we will issue a 12-month finding on the petition, which will
address whether the petitioned action is warranted, as provided in
section 4(b)(3)(B) of the Act.
DATES: To allow us adequate time to conduct this review, we request
that we receive information on or before May 31, 2011. Please note that
if you are using the Federal eRulemaking Portal (see ADDRESSES section,
below), the deadline for submitting an electronic comment is 11:59 p.m.
Eastern Time on this date. After May 31, 2011, you must submit
information directly to the Field Office (see FOR FURTHER INFORMATION
CONTACT section below). Please note that we might 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 eRulemaking Portal: http://www.regulations.gov. In
the box that reads ``Enter Keyword or ID,'' enter the Docket number for
this finding, which is FWS-R4-ES-2010-0084. Check the box that reads
``Open for Comment/Submission,'' and then click the Search button. You
should then see an icon that reads ``Submit a Comment.'' Please ensure
that you have found the correct document before submitting your
comment.
U.S. mail or hand-delivery: Public Comments Processing,
Attn: FWS-R4-ES-2010-0084; Division of Policy and Directives
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive,
Suite 222; Arlington, VA 22203.
We will not accept e-mail or faxes. We will post all information we
receive on the Internet at http://www.regulations.gov. This generally
means that we will post any personal information you provide us (see
the Request for Information section below for more details).
FOR FURTHER INFORMATION CONTACT: Stephen Ricks, Field Supervisor,
Mississippi Ecological Services Field Office, 6578 Dogwood View
Parkway, Jackson, MS 39213; by telephone (601-321-1122); or by
facsimile (601-965-4340). If you use a telecommunications
[[Page 18139]]
device for the deaf (TDD), please call the Federal Information Relay
Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Request for Information
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
spring pygmy sunfish from governmental agencies, Native American
Tribes, the scientific community, industry, and any other interested
parties. We seek information on:
(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, its
habitat, or both.
(2) The factors that are the basis for making a listing/delisting/
downlisting determination for a species under section 4(a) of the
Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et
seq.), which are:
(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.
If, after the status review, we determine that listing the spring
pygmy sunfish is warranted, we will propose critical habitat (see
definition in section 3(5)(A) of the Act), under section 4 of the Act,
to the maximum extent prudent and determinable at the time we propose
to list the species. Therefore, within the geographical range currently
occupied by the spring pygmy sunfish, we 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 the species is proposed
for listing, and why such habitat meets the requirements of section 4
of the Act.
Please include sufficient information with your submission (such as
scientific journal articles or other publications) to allow us to
verify any scientific or commercial information you include.
Submissions merely stating support for 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 a 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. If you submit
information via http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the
Web site. 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.
Information and supporting documentation that we received and used
in preparing this finding is available for you to review at http://www.regulations.gov, or you may make an appointment during normal
business hours at the U.S. Fish and Wildlife Service, Mississippi
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Background
Section 4(b)(3)(A) of the Act (16 U.S.C. 1533(b)(3)(A)) 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 the 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
promptly conduct a species status review, which we subsequently
summarize in our 12-month finding.
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 a 12-month finding, 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.
Previous Federal Actions
On November 29, 1977, we proposed to list the spring pygmy sunfish
as endangered and to designate critical habitat (42 FR 60765). We
withdrew the critical habitat portion of the proposal on March 6, 1979
(44 FR 12382). We then proposed critical habitat again for the species
on July 27, 1979 (44 FR 44418). On January 24, 1980, we withdrew the
pending proposal to list the spring pygmy sunfish, along with the
proposed critical habitat designation (effective November 29, 1979) (45
FR 5782).
The spring pygmy sunfish has been included in the following notices
as a candidate species for listing: December 30, 1982 (47 FR 58454);
September 18, 1985 (50 FR 37958); January 6, 1989 (54 FR 554); and
November 15, 1994 (59 FR 58982).
On February 28, 1996 (61 FR 7457), the Service published a notice
of review in the Federal Register that removed the spring pygmy sunfish
from the proposed candidate list because of recent discoveries
(particularly of the Pryor Springs population).
[[Page 18140]]
Petition History
On November 24, 2009, we received a petition dated November 24,
2009, from the Center for Biological Diversity (CBD) and Michael Sandel
of the University of Alabama, requesting that we list the spring pygmy
sunfish (Elassoma alabamae) as endangered under the Act. The petition
clearly identified itself as such and included the requested
identification information for the petitioners as required by 50 CFR
424.14(a). In a December 17, 2009, letter, we informed the petitioners
that we had reviewed the information presented in the petition, and
outlined the petition process and timelines. In July 2010, we received
letters from the North American Native Fishes Association (NANFA) and
Dr. Stallsmith (University of Alabama at Huntsville) requesting that we
emergency list the species under section 4(b)(7) of the Act. Following
review of the petition, the letters, and information in our files, we
also determined that issuing an emergency regulation temporarily
listing the species was not warranted. We notified NANFA and Dr.
Stallsmith of our determination on July 21, 2010.
Species Information
The spring pygmy sunfish (Elassoma alabamae) was discovered in 1938
but was not described until 1993 (Mayden 1993, pp. 1-14). This species
is the smallest member of the genus Elassoma. Males are normally
smaller than females, and both sexes have 5 to 8 broad, dark vertical
bars separated by light-colored, narrow bars. Males are very dark to
black with iridescent blue green color on their sides, cheeks, and gill
covers (Boschung and Mayden 2004, pp. 614-615).
The spring pygmy sunfish is a spring-associated fish, endemic to
the Tennessee River drainage in the Eastern Highland Rim physiographic
province and Dissected Tablelands (Curtis et al. 1913, p. 53) of
Lauderdale and Limestone Counties in northern Alabama. The single
remaining population of the spring pygmy sunfish currently occupies
about 5 river miles (mi) (8.05 river kilometers (km)) of shallow,
vegetated areas within four spring pools confluent with the upper
Beaver Dam Spring Complex. These spring pools include Moss, Beaverdam,
Thorsen, and Horton Springs, all in Limestone County, Alabama. The
species is thought to be extirpated in Pryor Springs (also in Limestone
County).
The spring pygmy sunfish was initially discovered in Cave Springs
(Lauderdale County) in 1938, and extirpated about a year later due to
inundation from the formation of Pickwick Reservoir. In 1941, the
species was discovered in Pryor Springs (Limestone County). A series of
geomorphic and contamination events over 30 years is believed to have
attributed to the demise of the species in Pryor Springs and throughout
the species' range--(Boschung and Mayden 2004, pp. 614-615). There are
few documented sampling efforts in Pryor Springs between 1966 and 1979.
However, collection information from this time period indicates a
declining and almost extinct population, nearing extirpation. By 1984,
an effort to re-establish the population of spring pygmy sunfish
included transplanting the species from Moss Spring into Pryor Springs
(Mettee et al. 1986, pp. 14-15). Reintroduction efforts continued in
1985 and 1987 (Mettee et al. 1986, pp. 6-7); however, by 2007, the
species was believed extirpated from Pryor Springs due to impaired
water quality and quantity problems, most likely attributable to
agriculture (Sandel 2008, p. 2).
The preferred habitat for the spring pygmy sunfish is clear and
colorless to slightly stained spring water, spring runs, and associated
spring-fed wetlands (Warren 2004, pp. 184-185). Spring pool habitats
are typically static, persisting without disturbance for long periods.
The spring pygmy sunfish is highly localized within these spring pools,
being found in the water column associated with patches of specific
submergent vegetation. Spring pygmy sunfishes are generally found at
water depths from 5 to 40 inches (in) (12.7 cm to 101.6 centimeters
(cm)) and rarely in the upper 5 in (12.7 cm) of the water column.
Spring pygmy sunfish abundance is correlated with specific water
quantity and quality parameters (i.e., water flow velocity, turbidity,
anoxic (lack of oxygen) substratum, and water temperatures) and certain
associated species such as amphipods, isopods, spring salamanders,
crayfish, and snails (Sandel, pers. comm., 2007). The spring pygmy
sunfish has high fecundity and quickly populates areas of available
habitat (Sandel, pers. obs., 2004 through 2009). Reproductively active
adults occur from January to October. Spawning occurs in March and
April, when water quality parameters are within a suitable range, such
as a pH of 6.0 to 7.7 and water temperatures of 57.2 to 68 degrees
Fahrenheit ([deg]F) (14 to 20 degrees Celsius ([deg]C)). Spring pygmy
sunfish produce about 65 eggs, and hatching occurs from April to
September (Sandel, pers. obs., 2004 through 2009).
The species is most abundant at the spring emergence, and exhibits
metapopulation (a group of spatially separated populations of the same
species that have some interaction) structure by occupying all suitable
spring habitats where there is flowing spring water. This suggests that
the population in the Beaverdam Creek system is a single, structured,
continuous group of breeding individuals, genetically identifiable with
limited gene flow from each springhead subpopulation (Sandel 2008, pp.
15-16).
It is believed that migration between springheads is very important
in maintaining genetic diversity of species within these small areas,
although gene flow is limited. Even though individual subpopulations
may be extirpated at times, due to drought or other ecological issues,
the simultaneous loss of many subpopulations may cause extinction of
the metapopulation.
We accept the characterization of the spring pygmy sunfish as a
valid species based on the taxonomic characters distinguishing the
species from other members of the Elassoma genus (Mayden 1993, p. 4).
Evaluation of Information for This Finding
Section 4 of the Act (16 U.S.C. 1533) and its implementing
regulations at 50 CFR 424 set forth the procedures for adding a species
to, or removing a species from, the Federal Lists of Endangered and
Threatened Wildlife and Plants. A species may be determined to be an
endangered or a 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 threats to the spring pygmy sunfish, presented in the
petition and available in our files, is substantial, thereby indicating
that the petitioned action may be warranted. Our evaluation of this
information is presented below.
[[Page 18141]]
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Information Provided in the Petition
The petition states that decreased water quantity has degraded the
spring pygmy sunfish's habitat (Warren et al. 2000; Warren 2004;
Boschung and Mayden 2004) (cited in petition). Specifically, water from
the aquifer of the Eastern Highland Rim located within the Tennessee
River Catchment containing the entire Beaverdam Creek watershed is
being withdrawn daily by the city of Huntsville and adjacent rural
residents at a volume of 40 million gallons per day (MGD) (Compiled
from NAWQA 2001, 2009; Sandel, pers. com, 2007).
The petition states that this water withdrawal quantity is at least
three times greater than the withdrawal volumes from the eight
surrounding watersheds that remove at least 12 MGD. Groundwater
extraction by agriculture from the springs (Thorsen Spring, Horton
Spring, and Pryor Branch/Spring systems), with five diesel irrigation
pumps operating simultaneously, withdraws 8,000 to 16,000 gallons per
minute during drought conditions. In 2007, water from Thorsen Spring
was extracted to a level that destroyed existing vegetation and
decreased the abundance of the spring pygmy sunfish abundance by 99
percent (Sandel, pers. obs., 2004 through 2007). Chronic regional
drought between 2000 and 2005 reduced rates of surface water flow and
aquifer recharge. Desiccation of aquatic vegetation by water removal
(pumping) within Thorsen, Horton, and Pryor Springs negatively impacted
the vegetation of the spring pygmy sunfish's habitat (Jandebeur 1979;
Mayden 1993; as cited in the petition).
The petition states that declining water quality is a major threat
to the spring pygmy sunfish due to the use of fertilizers and other
agricultural chemicals within the Beaverdam Creek watershed. According
to the petition, the watershed contains about 14,016 acres (5672.28 ha)
of row cropland that uses fertilizers and other chemicals, which is
eventually transported at a runoff rate exceeding 25 MGD throughout the
tributaries of the watershed.
The petition states that removal of aquatic and riparian vegetation
due to herbicide application is a major threat to the spring pygmy
sunfish. Herbicide application and other methods of aquatic vegetation
removal within Thorsen Spring, Horton Spring, and Pryor Branch/Spring
systems have impacted the species' habitat (Jandebeur 1979; Mayden
1993) (cited in petition).
Evaluation of Information Provided in the Petition and Available in
Service Files
Data from our files support the petition's assertion that
diminishing water quantity has the potential to be a significant threat
to the spring pygmy sunfish. Increased urbanization within the entire
Eastern Highland Rim topographic area (Woodside et al. 2001, p. 6) has
increased water quantity usage throughout the Tennessee Valley Basin.
Demand for water is correlated to projected population levels in
Limestone and Lauderdale Counties. By 2015, the population in these
counties is projected to increase dramatically (Roop 2010). Growing
populations correspondingly increase demand for surface and ground
water extraction within the Eastern Highland Rim. Currently about 40
percent of the public water supply for the City of Huntsville is
withdrawn from the Tennessee River and 40 percent from groundwater
(Hoos et al. 2001, p. 1; Kingsbury 2003, p. 2).
The information in our files regarding groundwater extraction for
Lauderdale and Limestone Counties is limited to general watershed and
county-level data (USGS 2009a; USGS 2009b; Hutson et al. 2005, pp. 1-
2). The petition only estimates the potential of eight pumps operating
simultaneously within the spring pygmy sunfish's sites. Information in
our files, along with field observations (Drennen, pers. obs., 2007
through 2009), supports the petition's claim that water is being
withdrawn from spring pygmy sunfish habitat for irrigation. However,
the specific water quantity removed from these sites and the impact
that this removal has on the spring pygmy sunfish is not substantiated,
and we do not have supporting information within our files.
Declining water quality information presented in the petition for
the Eastern Highland Rim, in general, is supported by information found
in our files. Specific site threats to the spring pygmy sunfish
mentioned in the petition, such as excessive sediment, decreasing water
clarity, decreasing spawning and feeding sites, reduction of light, and
the use of fertilizers and pesticides, were identified by the petition
as impacting the broad topographic region that includes the limited
sites occupied by the spring pygmy sunfish. However, the significance
of this general threat to the spring pygmy sunfish is unknown.
Information in our files supports the petition's assertion that
decreased water quality may be a threat to the spring pygmy sunfish.
Information in the petition and in our files indicates that, since
1945, various techniques for removing or limiting aquatic vegetation,
such as herbicides, cattle grazing, and irrigation, have occurred
within the spring systems and waterways throughout the habitat of the
spring pygmy sunfish (Jandebeur 1979, pp. 4-8). The information in our
files also supports the statement in the petition that manipulation and
control of aquatic vegetation in the spring systems may be a threat to
the spring pygmy sunfish.
In summary, we find that the information provided in the petition,
as well as other information in our files, presents substantial
information indicating that the petitioned action may be warranted due
to the present or threatened destruction, modification, or curtailment
of the species' habitat or range, specifically because of declining
water quantity and quality and loss of aquatic vegetation.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes.
Information Provided in the Petition
The petition states that overutilization has not been implicated in
the decline of this species because monthly surveys over the last 5
years for scientific evaluation were nonlethal. Previous lethal
sampling of the spring pygmy sunfish within the various sites across
the species' range for genetic work never constituted more than 10
percent of the total individuals collected per sampling event. The
petition states that there is no evidence to suggest over-exploitation
as a cause for the decline of the spring pygmy sunfish.
Evaluation of Information Provided in the Petition and Available in
Service Files
There is no evidence provided by the petition, or within our files,
to support threats under this factor. Therefore, we find that the
information provided in the petition, as well as other information in
our files, does not indicate or document that overutilization for
commercial, recreational, scientific or educational purposes poses a
threat to the species. However, we will evaluate all factors, including
overutilization for commercial, recreational, scientific, or
educational purposes, when we conduct the status review.
C. Disease or Predation
Information Provided in the Petition
The petition states that there is no evidence to suggest that
disease is a
[[Page 18142]]
cause for the decline of the spring pygmy sunfish. However, the
petition does state that chain pickerel (Esox nigra) prey on the spring
pygmy sunfish (Jandebeur 1997, cited in petition), and that other types
of pygmy sunfish species in different localities have been found in the
gut contents of piscivorous (fish-eating) fishes (Walsh and Burr 1984,
cited in petition). The petition states that invasive species, such as
predators like pirate perch (Aphredoderus sayanus) and grass pickerel
(Esox americanus), and potential competitors such as the flier
(Centrarchus macropterus) and bantam sunfish (Lepomis symmetricus),
threaten the spring pygmy sunfish.
Evaluation of Information Provided in the Petition and Available in
Service Files
The information in our files supports the assertion in the petition
that disease is not a threat to the spring pygmy sunfish. Predation
does pose a potential threat to the spring pygmy sunfish.
In summary, we find that neither the information in the petition,
nor other information in our files, indicates that disease is a threat
to the spring pygmy sunfish. However, we find that the information
provided in the petition, as well as other information in our files,
suggests that predation by natural or invasive species may pose a
threat to the spring pygmy sunfish. We will evaluate all factors,
including disease and predation, when we conduct the status review.
D. The Inadequacy of Existing Regulatory Mechanisms
Information Provided in the Petition
The petition states that the spring pygmy sunfish is not formally
recognized or protected at any government level. Current State and
Federal laws and regulations involving alteration of wetlands;
channelization; water withdrawal; pesticide use and other agriculture
best management practices; and buffer zones to protect water quality
and quantity within spring systems are available, but these do not
prohibit destroying the spring pygmy sunfish or its habitat.
Evaluation of Information Provided in the Petition and Available in
Service Files
The spring pygmy sunfish and its habitat are afforded some
protection from water quality and habitat degradation under the Clean
Water Act of 1977 (33 U.S.C. 1251 et seq.) and the Alabama Water
Pollution Control Law (Code of Alabama, sections 22-22-1 et seq., and
regulations promulgated thereunder by the Alabama Department of
Environmental Management) (Maynard and Gale. 1995, pp. 20-28). While
these laws have resulted in some improvement in water quality and
stream habitat for aquatic life, including the spring pygmy sunfish,
such as requiring landowners engaged in agricultural practices to have
an erosion prevention component within their farm plan, they alone have
not been fully adequate to protect this species due to inconsistent
implementation, monitoring, and enforcement. Furthermore, habitat
degradation is ongoing despite the protection afforded by these laws.
The State of Alabama maintains water-use classifications through
issuance of National Pollutant Discharge Elimination System (NPDES)
permits to industries, municipalities, and others that set maximum
limits on certain pollutants or pollutant parameters. For water bodies
on the Clean Water Act's Section 303(d) List of Impaired Water Bodies,
States are required under the Clean Water Act to establish a Total
Maximum Daily Load (TMDL) for the pollutants of concern that will bring
water quality into the applicable standard. Many of the water bodies
that do not meet Clean Water Act standards are within the occupied
range of the spring pygmy sunfish (Alabama 2008 Section 303(d) List of
Impaired Water Bodies).
The State of Alabama's water quality standards, adopted from the
national standards set by the U.S. Environmental Protection Agency
(USEPA), appear to be protective of the spring pygmy sunfish as long as
discharges are within permitted limits and are enforced according to
the provisions of the Clean Water Act. These water quality requirements
were established with the intent to protect all aquatic resources
within the State of Alabama and are presumed to be protective of the
spring pygmy sunfish. The Service is currently in consultation with the
USEPA to evaluate the efficacy of criteria approved in USEPA's water
quality standards for endangered and threatened species and their
critical habitats as described in the Memorandum of Agreement our
agencies signed in 2001 (66 FR 11201; February 22, 2001). Because the
spring pygmy sunfish is not currently a federally listed species, it is
not specifically considered in the ongoing consultation with USEPA.
Water extraction has also been identified as a potential threat to
the species (see Factor A above). There are few, if any, State and
Federal regulations pertaining to ground water extraction and
protection of aquifer recharge areas.
In summary, the petition's claim that there are no existing
regulatory mechanisms that protect the spring pygmy sunfish or its
habitat from destruction is not supported by the information in our
files. However, the information in our files indicates that degradation
of habitat for this species is ongoing despite the protections afforded
by these existing laws. Therefore, the information in the petition and
in our files presents substantial information indicating that the
petitioned action may be warranted due to the inadequacy of existing
regulatory mechanisms, particularly those affording protection from
habitat destruction or degradation.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Information Provided in the Petition
The petition states that the Beaverdam Creek metapopulation is
considered a single, semi-continuous group of subpopulations (Sandel,
pers. comm., 2007; Sandel 2008, pp. 13-14), and that impediments to
migration and gene flow between springheads are detrimental to
maintaining genetic diversity in the species. Individuals from each
site are genetically identifiable in a structured population, with
limited, but regular, gene flow. The genetic viability of
subpopulations is interdependent. Subpopulations may be naturally
extirpated at times, and the simultaneous loss of many subpopulations
may cause the metapopulation to become extinct. The petition states
that inbreeding is a potential factor in the decline of the spring
pygmy sunfish in Pryor Springs due to the reintroduction of too few
individuals (Mettee et al. 1986; Sandel 2008) (as cited in petition).
The petition states that if Asian silver and bighead carps
(Hypopthalmichthys spp.) are introduced or expand their range from
their present locality in the lower Tennessee River and Wheeler
Reservoir systems, they may disturb the Beaverdam Creek plankton
ecosystem by consuming significant proportions of plankton. The
petition also states that invasive plant species, such as floating
Amazonian parrot feather (Myriophyllum aquaticum) and water hyacinth
(Eichhornia sp.), and the submerged aquatic vegetation Myriophyllum
verticillatum and Ceratophyllum echinatum, threaten the Beaverdam Creek
ecosystem by competitively excluding native vegetation and storing
important nutrients within their aerial stems and
[[Page 18143]]
leaves, resulting in little nutrition or cover for the food base of the
species (no reference cited in the petition).
Evaluation of Information Provided in the Petition and Available in
Service Files
Data from our files support the petition's assertion that
impediments to migration and gene flow between springheads are
detrimental to maintaining genetic diversity in the species, and
therefore may be a significant threat to the spring pygmy sunfish.
Mechanical fragmentation of the species' habitat into smaller,
isolated subpopulations has transpired due to localized environmental
degradation from agriculture, increased urbanization, and other
anthropogenic disturbances of the spring systems throughout the
watersheds of the Eastern Highland Rim (Sandel 2008, pp. 2-4, 13). This
fragmentation of the spring pygmy sunfish's habitat has the potential
to impose negative selective pressures on the species' populations,
including genetic isolation; reduction of space for rearing,
recruitment, and reproduction; reduction of adaptive capabilities and
increased likelihood of local extinctions (Burkhead et al. 1997, pp.
397-399). Connectivity of these fragmented habitats as a whole allows
improvement in water quality by flushing and diluting possible
pollutants and in water quantity by linking the water bodies together.
Connectivity also maintains flow between the existing occupied habitat
and unoccupied habitat, which, in turn, allows for the potential of
colonization of these unoccupied habitat areas when conditions become
favorable for the species. In addition, the connectivity also maintains
heterozygosity (genetic diversity), or gene flow between the
populations of the species, and reduces inbreeding, thereby maintaining
the integrity of the population (Hallerman 2003, pp. 363-364).
However, we find that the information provided in the petition and
in our files does not support the claim that Asian silver and bighead
carps, or invasive plant species, pose a threat to the spring pygmy
sunfish at this time.
In summary, we find the information provided in the petition, as
well as other information in our files, concerning habitat
fragmentation and its resulting effects on gene flow and potential
demographic impacts within the population is substantial, indicating
that the petitioned action may be warranted due to other natural or
manmade factors affecting the spring pygmy sunfish's continued
existence.
Finding
On the basis of our review under section 4(b)(3)(A) of the Act, we
have determined that the petition presents substantial scientific or
commercial information indicating that listing the spring pygmy sunfish
throughout its entire range may be warranted. This finding is based on
information provided under Factors A, C, D and E. In considering what
factors might constitute threats, we must look beyond the mere exposure
of the species to the factor to determine whether the species responds
to the factor in a way that causes actual impacts to the species. If
there is exposure to a factor, but no response, or only a positive
response, that factor is not a threat. If there is exposure and the
species responds negatively, the factor may be a threat and we then
attempt to determine how significant a threat it is. If the threat is
significant, it may drive or contribute to the risk of extinction of
the species such that the species may warrant listing as endangered or
threatened as those terms are defined by the Act. This does not
necessarily require empirical proof of a threat. The combination of
exposure and some corroborating evidence of how the species is likely
impacted could suffice. The mere identification of factors that could
impact a species negatively may not be sufficient to compel a finding
that listing may be warranted. The information should contain evidence
sufficient to suggest that these factors may be operative threats that
act on the species to the point that the species may meet the
definition of endangered or threatened under the Act.
Because we have found that the petition presents substantial
information indicating that listing may be warranted, we are initiating
a status review to determine whether listing the spring pygmy sunfish
under the Act is warranted.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Mississippi
Ecological Services Field Office, 6578 Dogwood View Parkway, Jackson,
MS 39213.
Authors
The primary author of this notice is Daniel J. Drennen of the
Mississippi Ecological Services Field Office, Jackson, MS (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: March 16, 2011.
Rowan W. Gould,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-7691 Filed 3-31-11; 8:45 am]
BILLING CODE 4310-55-P