[Federal Register: June 22, 2010 (Volume 75, Number 119)]
[Proposed Rules]
[Page 35398-35424]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22jn10-23]
[[Page 35398]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R6-ES-2008-0088]
[MO 92210-0-0008-B2]
Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition to List the Least Chub as Threatened or Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the least chub (Iotichthys
phlegethontis), a fish, as threatened or endangered and to designate
critical habitat under the Endangered Species Act of 1973, as amended
(Act). After review of all available scientific and commercial
information, we find that listing the least chub as threatened or
endangered under the Act is warranted. Currently, however, listing the
least chub is precluded by higher priority actions to amend the Lists
of Endangered and Threatened Wildlife and Plants. Upon publication of
this 12-month petition finding, we will add the least chub to our list
of candidate species with a listing priority number (LPN) of 7. We will
develop a proposed rule to list this species as our priorities and
funding allow. We will make any determination on critical habitat
during development of the proposed listing rule. In the interim, we
will address the status of the candidate taxon through our annual
Candidate Notice of Review (CNOR).
DATES: This finding was made on June 22, 2010.
ADDRESSES: This finding is available on the Internet at http://
www.regulations.gov at Docket Number FWS-R6-ES-2008-0088 and http://
www.fws.gov/mountain-prairie/species/fish/leastchub. Supporting
documentation we used in preparing this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Utah Ecological Services Field Office, 2369
West Orton Circle, Suite 50, West Valley City, UT 84119. Please submit
any new information, materials, comments, or questions concerning this
finding to the above address.
FOR FURTHER INFORMATION CONTACT: Larry Crist, Field Supervisor, U.S.
Fish and Wildlife Service, Utah Ecological Services Field Office (see
ADDRESSES); by telephone at (801) 975-3330; or by facsimile at (801)
975-3331. Persons who use a telecommunications device for the deaf
(TDD) may call the Federal Information Relay Service (FIRS) at 800-877-
8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.), requires
that, for any petition to revise the Federal Lists of Threatened and
Endangered Wildlife and Plants that contains substantial scientific or
commercial information indicating that listing the species may be
warranted, we make a finding within 12 months of the date of receipt of
the petition. In this finding, we determine that the petitioned action
is: (a) Not warranted, (b) warranted, or (c) warranted, but immediate
proposal of a regulation implementing the petitioned action is
precluded by other pending proposals to determine whether species are
threatened or endangered, and expeditious progress is being made to add
or remove qualified species from the Federal Lists of Endangered and
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires
that we treat a petition for which the requested action is found to be
warranted but precluded as though resubmitted on the date of such
finding, that is, requiring a subsequent finding to be made within 12
months. We must publish these 12-month findings in the Federal
Register.
Previous Federal Actions
In 1980, the Service reviewed the status of the least chub and
determined that there was insufficient data to warrant its listing as
an endangered or threatened species under the Act. On December 30,
1982, we classified the least chub as a Category 2 Candidate Species
(47 FR 58454). Category 2 included taxa for which information in the
Service's possession indicated that a proposed listing rule was
possibly appropriate, but for which sufficient data on biological
vulnerability and threats were not available to support a proposed
rule. In 1989, we conducted a new status review, and reclassified the
least chub as a Category 1 Candidate Species (54 FR 554). Category 1
included taxa for which the Service had substantial information in our
possession on biological vulnerability and threats to support
preparation of listing proposals. The Service ceased using category
designations in February 1996. On September 29, 1995, we published a
proposed rule to list the least chub as endangered with critical
habitat (60 FR 50518). A listing moratorium, imposed by Congress in
1995, suspended all listing activities and further action on the
proposal was postponed.
During the moratorium, the Service, Utah Division of Wildlife
Resources (UDWR), Bureau of Land Management (BLM), Bureau of
Reclamation (BOR), Utah Reclamation Mitigation and Conservation
Commission (URMCC), Confederated Tribes of the Goshute Reservation, and
Central Utah Water Conservancy District (CUWCD) developed a Least Chub
Conservation Agreement and Strategy (LCCAS), and formed the Least Chub
Conservation Team (LCCT) (Perkins et al. 1998, entire). The goals of
the LCCAS are to ensure the species' long-term survival within its
historic range and to assist in the development of rangewide
conservation efforts. The objectives of the LCCAS are to eliminate or
significantly reduce threats to the least chub and its habitat, to the
greatest extent possible, and to ensure the continued existence of the
species by restoring and maintaining a minimum number of least chub
populations throughout its historic range. The LCCT implements the
LCCAS and monitors populations, threats, and habitat conditions. The
LCCAS was updated and revised in 2005 (Bailey et al. 2005, entire).
As a result of conservation actions and commitments made by
signatories to the 1998 LCCAS (Perkins et al. 1998, p. 10), measures to
protect the least chub were developed and implemented. Consequently, we
withdrew the listing proposal on July 29, 1999 (64 FR 41061).
On June 25, 2007, we received a petition dated June 19, 2007, from
Center for Biological Diversity, Confederated Tribes of the Goshute
Reservation, Great Basin Chapter of Trout Unlimited, and Utah Chapter
of the Sierra Club requesting that the least chub be listed as
threatened under the Act and critical habitat be designated. Included
in the petition and supplement was supporting information regarding the
species' taxonomy and ecology, historical and current distribution,
present status, and actual and potential causes of decline. We
acknowledged the receipt of the petition and supplement in a letter to
Center for Biological Diversity, Confederated Tribes of the Goshute
Reservation, Great Basin Chapter of Trout Unlimited, and Utah Chapter
of the Sierra Club, dated July 13, 2007. In that letter, we also stated
that because of staff and budget limitations, it was not practical for
us to begin processing the petition at that time. Based on the
population status and alleged threats described in the
[[Page 35399]]
petition, we found no compelling evidence to support an emergency
listing at that time.
Funding became available to begin work on the 90-day finding in
Fiscal Year (FY) 2008. On October 15, 2008, we published a 90-day
finding that the petitioners provided substantial information
indicating that the species may be warranted for listing under the Act,
initiated the 12-month finding, and opened a 60-day public comment
period (73 FR 61007). This notice constitutes the 12-month finding on
the June 19, 2007, petition to list the least chub as threatened or
endangered.
Species Information
Taxonomy and Species Description
The least chub (Iotichthys phlegethontis) is an endemic minnow
(Family Cyprinidae) of the Bonneville Basin in Utah. Historically,
ancient lakes Bonneville and Provo largely covered the Bonneville
Basin, but over the past 16,000 years (since the Pleistocene period),
these lakes receded, leaving behind the current hydrology of the area
(Currey et al. 1984, p. 1). Least chub likely persisted in peripheral
freshwater sources to the receding lakes and were widely distributed in
a variety of the resulting habitat types, including rivers, streams,
springs, ponds, marshes, and swamps (Sigler and Miller 1963, p. 91).
The species' taxonomic classification has evolved over time, as
described in the 1995 proposed rule (60 FR 50518). The least chub is
currently classified within the monotypic genus (containing only one
species) Iotichthys (Jordan et al. 1930, in Hickman 1989, p. 16; Robins
et al. 1991, p. 21).
As implied by its common name, the least chub is a small fish less
than 55 millimeters (2.1 inches) long, identified by an upturned or
oblique mouth, large scales, and the absence of an incomplete lateral
line (rarely with one or two pored scales) (Sigler and Sigler 1987, p.
182). It has a deeply compressed body, with the front-most part of the
dorsal fin (on the back) lying behind the insertion of the pelvic fin
(on the underside of the body), and a slender caudle peduncle (area
connecting tail fin to the body) (Sigler and Miller 1963, p. 83).
Dorsal fin rays number eight (rarely nine), and anal fin rays also
number eight (Sigler and Miller 1963, p. 83). The pharyngeal teeth
(located near the pharynx) are in two rows (Sigler and Miller 1963, p.
83).
The least chub is a colorful species. Individuals have a gold
stripe along blue sides with white to yellow fins (Sigler and Sigler
1987, p. 182). Spawning males are olive-green above, steel-blue on the
sides, and have a golden stripe behind the upper end of the gill
opening (Sigler and Sigler 1987, p. 182). The fins are lemon-amber, and
sometimes the paired fins are bright golden-amber (Sigler and Sigler
1987, p. 182). Females and young are pale olive above, silvery on the
sides, and have watery-white fins; their eyes are silvery, with a
little gold coloration (Sigler and Sigler 1987, p. 182).
Life History
Sigler and Sigler (1987, p. 183) considered the least chub to be a
slow-growing species that rarely lives beyond 3 years of age. However,
least chub in natural systems live longer than originally thought (some
least chub may live to be 6 years of age) and growth rates vary among
populations (Mills et al. 2004a, p. 409). Differences in growth rates
may result from a variety of interacting processes, including food
availability, genetically based traits, population density, and water
temperatures (Mills et al. 2004a, p. 411).
Least chub are opportunistic feeders, and their diets reflect
availability and abundance of food items in different seasons and
habitat types (Crist and Holden 1980, p. 808; Lamarra 1981, p. 5;
Workman et al. 1979, p. 23). Although least chub diets change
throughout the year, they regularly consume algae (Chlorophyta and
Chrysophyta), midges (Chironomidae), microcrustaceans, copepods,
ostracods, and diatomaceous material (Sigler and Sigler 1987, p. 183).
Maintaining hydrologic connections between springheads and marsh
areas is important in fulfilling the least chub's ecological
requirements (Crawford 1979, p. 63; Crist and Holden 1980, p. 804;
Lamarra 1981, p. 10). Least chub follow thermal patterns for habitat
use. In April and May, they use the flooded, warmer, vegetated marsh
areas at water temperatures of about 16 [deg]C (60 [deg]F) (Crawford
1979, pp. 59, 74), but in late summer and fall they retreat to spring
heads as the water recedes, to overwinter (Crawford 1979, p. 58). In
the spring, the timing of spawning is a function of temperature and
photoperiod (Crawford 1979, p. 39).
The least chub is a partial and intermittent spawner, and spawns
within aquatic vegetation (Crawford 1979, p. 74). Adhesive eggs attach
to the emergent plants that provide the eggs, larvae, and young with
oxygen, food, and cover (Crist and Holden 1980, p. 808). Females
release only a few eggs at a time, but continue spawning for an
extended period. Total numbers of eggs produced are an indication of
fecundity, and individual females produce from 300 to 2,700 eggs
(Crawford 1979, p. 62). Fertilized eggs hatch in approximately 2 days
at a water temperature of 22 [deg]C (72 [deg]F) (Crawford 1979, p. 74).
Although peak spawning activity occurs in May, the reproductive season
lasts from April to August, and sometimes longer, depending on
environmental conditions such as photoperiod and water temperature
(Crawford 1979, pp. 47-48). This reproductive strategy (i.e.,
repetitive spawning over a period of many weeks) allows the least chub
to persist in fluctuating environmental conditions typical of desert
habitats (Crawford 1978, p. 2).
Larval least chub grow larger and young fry survive better in silt
substrate habitats (Wagner et al. 2006, pp. 1, 4, 7). The maximum
growth rate for least chub less than 1 year of age occurs at 22.3
[deg]C (72 [deg]F) under captive conditions (Billman et al. 2006, p.
434). Thermal preferences demonstrate the importance of warm rearing
habitats in producing strong year classes and viable populations
(Billman et al. 2006, p. 434).
Distribution
The first documented collection of least chub is from a ``brook''
near Salt Lake City in 1871 (Hickman 1989, p. 16). Between 1871 and
1979, many least chub occurrences were reported across the State,
ranging from the eastern portions of the Snake Valley to the Wasatch
Front and from the northern extent of the Bear River south to the
Beaver River (table 1). Least chub were very common in tributaries to
the Sevier, Utah, and Great Salt Lakes in the beginning of the 20th
Century (Jordan 1891, p. 30; Jordan and Evermann 1896, in Hickman 1989,
p. 1).
Table 1.--Summary of historic collections of least chub.
----------------------------------------------------------------------------------------------------------------
GEOGRAPH AREA Location Year Collected Reference
----------------------------------------------------------------------------------------------------------------
Wasatch Front Northwest Salt Lake 1933 Hickman 1989, pp. 16-17
City
----------------------------------------------------------------------------------------------------------------
qdrt;;
[[Page 35400]]
Big Cottonwood Creek 1953 Sigler & Miller 1963,
pp. 82-83
----------------------------------------------------------------------------------------------------------------
qdrt;;Davis County (2 1964 Hickman 1989, pp. 16-
miles west of 17; Bailey et al.
Centerville) 2005, p. 16
----------------------------------------------------------------------------------------------------------------
qdrt;;Farmington Bay 1965 Hickman 1989, pp. 16-
17; Bailey et al.
2005, p. 16
----------------------------------------------------------------------------------------------------------------
qdrt;;Provo River 1891 Jordan 1891, p. 30
----------------------------------------------------------------------------------------------------------------
qdrt;;Provo River (at 1931 & 1936 Tanner 1936, p. 170
confluence with Utah
Lake)
======================================
Northern Bear River 1894 Thompson 2008, p. 1
======================================
Southern Beaver River 1875 Cope & Yarrow 1875, pp.
656-657
----------------------------------------------------------------------------------------------------------------
qdrt;;Beaver River; 1942 Hubbs et al. 1942, in
Parowan Creek; Clear Sigler & Miller 1963,
Creek; & Little Salt p. 82
Lake
----------------------------------------------------------------------------------------------------------------
qdrt;;Sevier Lake 1896 Jordan & Evermann 1896,
in Bailey et al. 2005,
p. 16
======================================
Snake Valley Chimneys Spring; Big 1942 Hickman 1989, p. 16-17
Spring; Foote Ranch;
Small Knoll; & Gandy
area
----------------------------------------------------------------------------------------------------------------
qdrt;;Leland Harris 1970 Hickman 1989, p. 16
Spring Complex & Gandy
Salt Marsh
----------------------------------------------------------------------------------------------------------------
qdrt;;Leland Harris 1979 Workman et al. 1979,
Spring Complex; Bishop pp. 157-159
Spring Complex (Foote
Reservoir & Twin
Spring); & Gandy
Spring Complex
----------------------------------------------------------------------------------------------------------------
qdrt;;Callao, Utah 1979 Workman et al. 1979,
(Bagley Ranch & Redden pp. 157-159
Spring)
----------------------------------------------------------------------------------------------------------------
By the 1940s and 1950s, the numbers of least chub were decreasing
(Holden 1974, in Hickman 1989, p. 2). Only 11 known populations existed
by 1979 (Workman et al. 1979, pp. 156-158). By 1989, least chub had not
been collected outside of the Snake Valley for the previous 25 years
(Hickman 1989, p. 2). Three wild least chub populations were extant in
1995 (60 FR 50518) (Leland Harris Spring Complex, Gandy Salt Marsh,
Bishop Spring Complex).
The current distribution of the least chub is highly reduced from
its historic range. The UDWR began surveying for new populations and
monitoring existing populations Statewide in 1993. As a result, UDWR
found three previously unknown populations of least chub: Mona Springs
in 1995, Mills Valley in 1998, and Clear Lake in 2003 (Mock and Miller
2003, p. 3; Hines et al. 2008, pp. 44-45). The Mona Springs site is in
the southeastern portion of the Great Salt Lake subbasin and occurs on
the eastern border of ancient Lake Bonneville, near the highly
urbanized Wasatch Front. Clear Lake and Mills Valley are both in the
Sevier subbasin, in relatively undeveloped sites (Hines et al. 2008, p.
17). A comparison of survey results from the 1970s (Workman et al.
1979, pp. 156-158) to surveys from 1993 to 2007 (Hines et al. 2008, pp.
36-45) indicates that a majority of the natural populations extant in
1979 were extirpated by 2007 (table 2).
Table 2.--Comparison of least chub collections in 1979 and their
updated status in 2007.
Asterisk (*) denotes populations discovered after 1979.
Status categories:
Stable = viable self-sustaining population
Functionally extirpated = a limited number of least chub
present but population is not self sustaining
Extirpated = least chub no longer present at that location
Secure = no immediate threats present
Not secure = immediate threat(s) present
------------------------------------------------------------------------
1979 Population Status in 2007
------------------------------------------------------------------------
Leland Harris Spring Complex Stable - Secure
===========================================
Gandy Salt Marsh Stable - Secure
===========================================
Bishop Springs Stable - Secure
===========================================
Mills Valley* Stable - Not secure
===========================================
Clear Lake Wildlife Management Area* Stable - Not secure
===========================================
Mona Springs* Functionally
extirpated
===========================================
Redden Springs Extirpated
===========================================
Bagley Ranch Complex Extirpated
===========================================
Knoll Spring (not verified) Extirpated
===========================================
Cecil Garland Ranch Extirpated
===========================================
Tie House Extirpated
===========================================
Donner Extirpated
===========================================
Cold Extirpated
------------------------------------------------------------------------
Five wild, extant populations of least chub remain: the Leland
Harris Spring Complex, Gandy Salt Marsh, Bishop Springs Complex, Mills
Valley, and Clear Lake (Hines et al. 2008, pp. 34-45). Three of these
populations (the Leland Harris Spring Complex, Gandy Salt Marsh, and
Bishop Spring Complex) occur in the Snake Valley of Utah's west desert
and are genetically similar and very close in proximity to
[[Page 35401]]
each other (Mock and Miller 2003, pp. 17-18). The two remaining extant
populations (Mills Valley and Clear Lake) are located on the
southeastern border of the native range.
Least chub are still found in small numbers at the Mona Springs
site (Hines et al. 2008, p. 37). However, because this small number of
least chub does not compose a viable self-sustaining population (LCCT
2008a, p. 3), we consider the least chub population at Mona Springs
functionally extirpated (see discussion below). The Snake Valley, Mills
Valley, Clear Lake, and Mona Springs populations are each genetically
distinct (Mock and Miller 2005, p. 276; Mock and Bjerregaard 2007, p.
146). A brief description of the extant wild and the Mona Springs least
chub populations is found below.
(1) Leland Harris Spring Complex: R.R. Miller first collected least
chub at this site, located north of the Juab/Millard County line, in
1970 (Sigler and Sigler 1987, p. 182). The site consists of 12 to 15
springheads that feed a playa wetland with habitat fluctuating in size
seasonally. Least chub have had a persistent presence since monitoring
began by the UDWR in 1993 (Hines et al. 2008, pp. 41-43). Another
spring in the area, Miller Spring, is part of the Leland Harris Spring
Complex, but outflows of the two sites are not always connected.
(2) Gandy Salt Marsh: C.L., L.C., and E.L. Hubbs first collected
least chub at this site in 1942 (Sigler and Miller 1963, p. 82). Gandy
Salt Marsh is south of the Millard/Juab County line and the Leland
Harris Spring Complex and consists of private Utah School and
Institutional Trust Lands Administration (SITLA) and BLM lands.
Measuring approximately 6.4 kilometers (km) (4 miles (mi)) long (north
and south) and 3.2 km (2 mi) wide (east and west), the complex consists
of approximately 52 small springheads or ponds that drain into a large
playa wetland on approximately 1,295 hectares (ha) (3,200 acres (ac))
(BLM 1992, p. 11). Least chub is the dominant fish species at the Gandy
Salt Marsh site and comprises a wild self-sustaining population (Hines
et al. 2008, p. 40). However, the number of occupied sites within the
marsh has decreased about 50 percent since 1994 (Wilson 2006, p. 8;
Hines et al. 2008, p. 41).
(3) Bishop Springs Complex: Least chub were documented at this site
in 1942 (Hickman 1989, p. 18). The complex is now the largest occupied
least chub site in Snake Valley. Located south and very near Gandy Salt
Marsh, the site has large springs containing least chub, including
Central Spring and Twin Springs (Hines et al. 2008, p. 38). The least
chub population in Bishop Springs has remained stable and has
demonstrated successful reproduction and recruitment (Hines et al.
2008, p. 38). The manmade Foote Reservoir does not contain least chub
but contributes water to the playa marshlands that provide seasonal
least chub foraging, reproduction, and nursery-type habitat (Crawford
1979, pp. 62-65).
(4) Mills Valley: UDWR biologists discovered least chub at multiple
locations at this site in 1998 (Hines et al. 2008, p. 44). Mills Valley
is in the Sevier River drainage in southeast Juab County (Hines et al.
2008, p. 17). It consists of a wetland with numerous springheads
throughout the 200-ha (495-ac) complex. The least chub were present
during sampling from 2001 through 2006 (Hines et al. 2008, p. 44).
(5) Clear Lake: In 2003, UDWR biologists found least chub at the
Clear Lake Wildlife Management Area (WMA) in Millard County (Hines et
al. 2008, p. 45). This reserve consists of a shallow reservoir and
diked ponds fed by springs from adjacent Spring Lake. The site is
managed by UDWR for waterfowl habitat (Hines et al. 2008, p. 45).
Information about this least chub population is limited because of its
recent discovery; however, successful recruitment is occurring (Hines
et al. 2008, p. 45).
(6) Mona Springs: The UDWR biologists discovered this least chub
site in northeast Juab County in 1995 (Mock and Miller 2003, p. 3).
Mona Springs has provided habitat for a genetically distinct, naturally
occurring population of least chub. However, the Mona Springs site is
no longer suitable for least chub because of the presence of nonnative
fish; only four least chub were collected here in 2008 surveys (LCCT
2008a, p. 3). Because of the lack of population viability at this site,
we consider the least chub population at Mona Springs functionally
extirpated.
Translocations
In an attempt to create refuge (an artificial place of protection
for a species) populations and reestablish wild populations, 19
introductions of least chub to new locations rangewide were attempted
by UDWR between 1979 and 2008 (see table 3). Of these, two sites are
currently stable and secure (one has persisted for 3 years and another
for 1 year), seven introductions failed, and three are not secure. The
long-term success of seven of the transplants is currently unknown,
because they were initiated in 2008 and monitoring information is
limited. A description of each of the translocation efforts follows.
Table 3.--Least chub translocations attempted from 1979 to 2008.
Status categories:
Stable = viable self-sustaining population
Unstable = a limited number of least chub present but
population is not self-sustaining
Extirpated = least chub no longer present at location
Secure = no immediate threats present
Not secure = immediate threat(s) present
Unknown = no established sampling history
------------------------------------------------------------------------
Site Year Status
------------------------------------------------------------------------
Lakepoint Pond 1979 Extirpated
=================================
Harley Sanders Pond 1986 Extirpated
=================================
Red Butte Gardens 1987 Extirpated
=================================
Walter Springs 1995 Extirpated
=================================
Deadman Springs 1996 Extirpated
=================================
Antelope Island 2000 Extirpated
=================================
Lucin Pond 1989 Unstable - Not
secure
=================================
Garden Creek Pond 2004 Stable - Not
secure
=================================
Atherly Reservoir 2006 Unstable - Not
secure
=================================
Ibis/Pintail Ponds 2007 Extirpated
=================================
Red Knolls Pond 2005 Stable -
Secure
=================================
Willow Pond 2007 Stable -
Secure
=================================
Seven northern Utah sites 2008 Unknown
------------------------------------------------------------------------
(1) Lakepoint Pond, Tooele County: In 1979, 200 least chub from the
Leland Harris Spring Complex were released into Lakepoint Pond located
approximately 32 km (20 mi) southwest of Salt Lake City, 1.6 km (1 mi)
from the shore of the Great Salt Lake. This site was eliminated by
floods in 1983 and 1984 (Hickman 1989, p. 4).
(2) Harley Sanders Pond, Box Elder County: In 1986, UDWR released
least chub into Harley Sanders Pond and spring. No least chub were
found during sampling in 1988 (Hickman 1989, p. 4).
(3) Red Butte Gardens, Salt Lake County: In 1987, least chub were
introduced into the stream and pond at the Utah State Arboretum (Red
Butte
[[Page 35402]]
Gardens) near Fort Douglas in Salt Lake City (Hickman 1989, p. 5).
Attempts to relocate least chub in 1988 were unsuccessful (Hickman
1989, p. 5), so we consider it extirpated and unsuccessful.
(4, 5) Walter/Deadman Springs, Tooele County: Least chub were
introduced in 1995 and 1996 to these springs; however, they have been
replaced by western mosquitofish (Gambusia affinis) (Wilson and Whiting
2002, p. 4; Wilson and Mills 2004, pp. 4-5). Therefore, we consider
these sites to be extirpated and unsuccessful.
(6) Antelope Island, Davis County: In December 2000, UDWR
introduced least chub to a human-made spring-fed pond on Antelope
Island. Mosquitofish have replaced least chub at this site (Thompson
2005, pp. 5-6). Therefore, we consider this site to be extirpated and
unsuccessful.
(7) Lucin Pond, Box Elder County: In 1989, 42 least chub were
transplanted into this site. Lucin Pond is a human-made pond built in
the early 1900s. This least chub population is currently considered
unstable and not secure because mosquitofish are present and the water
supply to the pond is unreliable (Thompson 2005, pp. 1-4; Hines et al.
2008, pp. 47-49).
(8) Garden Creek Pond, Davis County: In 2004, 947 least chub were
introduced to this pond on Antelope Island in the Great Salt Lake. It
is a 0.04 ha (0.1 ac) pond that was dredged by the Utah Department of
Parks and Recreation and is fed by a perennial stream (stream with
continuous flow throughout the year). The site was considered a genetic
refuge for the functionally extirpated Mona Springs population.
Reproduction and recruitment have been occurring; however, the site is
threatened by a loss of habitat due to siltation (Thompson 2005, pp. 6-
7; Hines et al. 2008, p. 46; Thompson 2008, p. 3; LCCT 2008a, pp. 3-4).
(9) Atherly Reservoir, Tooele County: This site is on Faust Creek
in Rush Valley, and is part of the 283-ha (700-ac) James Walter
Fitzgerald WMA. Approximately 13,000 least chub from the Mills Valley
population were introduced in 2006 (Hines et al. 2008, p. 50). The UDWR
monitoring in 2008 detected only eight least chub (LCCT 2008a, p. 3).
Therefore, we do not consider this introduction to be successful at
this time.
(10) Ibis/Pintail Ponds, Tooele County: In 2007, least chub from
Leland Harris Spring Complex were introduced into Ibis and Pintail
Ponds on the Fish Springs National Wildlife Refuge (Hines et al. 2008,
p. 50). This introduction was unsuccessful, and the site currently does
not contain a least chub population. The UDWR is planning to release
least chub again in the future after mosquitofish control issues are
addressed (LCCT 2008a, p. 3).
(11) Red Knolls Pond, Box Elder County: In 2005, 250 least chub
from Bishop Springs were introduced to Red Knolls Pond (Hines et al.
2008, p. 50), located in the western portion of Box Elder County on BLM
land. Successful recruitment was observed in 2005, 2006, and 2007,
indicating that reproduction has been occurring (Hines et al. 2008, p.
50; Thompson 2008, p. 4). This site is currently secure and represents
a genetic refuge for the Bishop Springs Complex population.
(12) Willow Pond, Box Elder County: On August 22, 2007, 340 least
chub from the Clear Lake population were released into this habitat
(Hines et al. 2008, p. 50), located in the northwest portion of Box
Elder County. In 2008, least chub were present and recruitment to the
population was apparent (LCCT 2008a, p. 4). This site is currently
secure and represents a genetic refuge for the Clear Lake population.
(13) The UDWR introduced least chub into seven additional sites in
Cache and Box Elder Counties in 2008 (LCCT 2008a, p. 4). This effort
was conducted to establish new refuge populations by stocking State-
hatchery-produced least chub into suitable habitat. Success of these
introductions cannot be determined for several years; however, the
probability of success for some of these introductions may be low
because of the possibility of winter kill and the presence of nonnative
species.
In summary, we believe that translocated least chub populations can
contribute to the long-term conservation of the species by providing a
refuge (e.g., hatcheries or other managed systems) for the preservation
of a population's genetic diversity. In addition, translocation to a
refugium (a native habitat that has escaped ecological changes
occurring elsewhere and so provides a suitable habitat for a species)
contributes to long-term conservation of least chub by providing
conditions necessary to maintain a viable self-sustaining population.
However, to date, translocated least chub populations have had
relatively poor success because of problems with competing nonnative
fishes, inadequate water supply, or for unknown reasons (i.e., least
chub were stocked into a particular habitat but could not be relocated
during subsequent monitoring). While two populations have indications
of successful recruitment and are secure from immediate threats, it is
too early to determine whether these populations will contribute to the
long-term conservation of least chub. Monitoring of translocated
populations will be essential to address the uncertainty that exists
about the success of these actions. Due to the uncertainty of the long-
term status of translocated least chub populations, they are not
considered further in this review.
Hatchery Broodstock
The Wahweap Warmwater Fish Hatchery in Big Water, Utah, and the
Fisheries Experiment Station in Logan, Utah, each manage least chub
broodstock that were sourced from Mills Valley and Mona Springs (Hines
et al. 2008, p. 27). These hatcheries help preserve the genetic
diversity of source populations of least chub and provide stock for
introduction and reintroduction efforts.
Summary of Information Pertaining to the Five Factors
Section 4 of the Act (16 U.S.C. 1533), and implementing regulations
(50 CFR 424), set forth procedures for adding species to the Federal
Lists of Endangered and Threatened Wildlife and Plants. Under section
4(a)(1) of the Act, a species may be determined to be endangered or
threatened based on any of the following five factors: (A) The present
or threatened destruction, modification, or curtailment of its habitat
or range; (B) overutilization for commercial, recreational, scientific,
or educational purposes; (C) disease or predation; (D) the inadequacy
of existing regulatory mechanisms; or (E) other natural or manmade
factors affecting its continued existence. In making this finding,
information pertaining to the least chub in relation to the five
factors provided in section 4(a)(1) of the Act is discussed below.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range.
The following potential threats that may affect the habitat or
range of least chub are discussed in this section, including: (1)
Livestock grazing; (2) oil and gas leasing and exploration; (3) mining;
(4) urban and suburban development; (5) water withdrawal and diversion;
and (6) drought.
(1) Livestock Grazing
Grazing animals can impact aquatic habitats in multiple ways.
Livestock seek springs for food and water, both of which are limited in
desert habitats; therefore, they spend a disproportionate amount of
time in these areas (Stevens
[[Page 35403]]
and Meretsky 2008, p. 29). As they spend time at springs, livestock eat
and trample plants, compact local soils, and collapse banks of springs
(Stevens and Meretsky 2008, p. 29). Input of organic wastes increases
nutrient concentrations, and some nutrients (i.e., nitrogen compounds)
can become toxic to fish (Taylor et al. 1989, in Stevens and Meretsky
2008, p. 29). Domestic animals can also be trapped in soft spring
deposits, die and decompose, and pollute the water. All of these
effects can result in the loss or decline of native aquatic fauna
(Stevens and Meretsky 2008, pp. 29-30).
As explained below, historic livestock grazing impacted four of the
five remaining wild least chub sites, and current livestock grazing
practices continue to impact these sites. The UDWR monitors these sites
and is working on minimizing or removing livestock grazing threats
(Hines et al. 2008, pp. 22-23). Livestock grazing impacts occur at
Mills Valley (Wilson and Whiting 2002, pp. 2-3; Bailey 2006, p. 30;
Hines et al. 2008, p. 43), Gandy Salt Marsh (Hines et al. 2008, p. 39;
LCCT 2008b, p. 2), Miller Spring/Leland Harris Spring Complex (Bailey
2006, p. 11; Hines et al. 2008, pp. 41-42), and Bishop Springs/Foote
Reservoir/Twin Springs (Wheeler and Fridell 2005, p. 5). The Clear Lake
site is protected from livestock grazing because it is a WMA managed by
the State of Utah (Hines et al. 2008, p. 45).
Fencing at Gandy Salt Marsh and Miller Spring/Leland Harris Spring
Complex excludes cattle from springhead areas (Hines et al. 2008, pp.
39, 41, 43), but livestock damage still occurs at these sites during
periods of unmanaged overgrazing or when fences are not maintained
(Hines et al. 2008, p. 39; LCCT 2008b, p. 2). For example, in July
2008, livestock damage was reported to be extensive and fencing trapped
cattle inside the northern area of Gandy Salt Marsh (LCCT 2008b, p. 2).
Impacts from livestock grazing include bank erosion and
sedimentation to springheads (LCCT 2008b, p. 5). Miller Spring (at the
Leland Harris Spring Complex) was unsuitable for least chub due to
sedimentation and trampling associated with livestock use, poor water
quality, and the presence of rainbow trout (Hogrefe 2001, p. 7).
Extensive efforts by UDWR in 1999 and 2000 to restore and fence the
spring and remove nonnatives significantly improved the habitat
(Hogrefe 2001, pp. 7, 20); however, the response of least chub to
improvements at Miller Spring has not been determined. Most of the
other 12 to 15 springs in the Leland Harris Spring Complex have some
ungulate damage and bank disturbance (Hines et al. 2008, p. 42). A
rotational grazing plan has been developed with the landowner and UDWR
on 75 ha (188 ac) of the Leland Harris site to improve habitat
conditions, but damage to springs and riparian vegetation continues to
impact least chub habitat (Hines et al. 2008, p. 42).
Twin Springs, at the Bishop Spring complex, is partially protected
from livestock by fences, but the larger spring complex, Twin Springs
South, is not protected from grazing or wild horse watering access.
Twin Springs South has severely impacted banks resulting in shallower
water, increased surface area, and sedimentation of spring heads
(Wheeler et al. 2004, p. 5). On the State-owned WMA portion of the
Mills Valley site, grazing is allowed in return for access across
private land. The private portion of Mills Valley is overgrazed and
damage to water body banks and riparian vegetation has been reported as
moderate to severe (UDWR 2006, pp. 27-28). The BLM has built fencing
around two Gandy Salt Marsh springheads, Pilot Springs and Red Knolls
Pond, to protect least chub transplant locations (Hines et al. 2008, p.
24).
In summary, our analysis indicates that, although efforts to
control and minimize damage have been implemented and are ongoing,
livestock grazing impacts some habitat at most wild least chub sites.
Grazing damage is not always severe where it occurs, and livestock are
effectively excluded from portions of occupied habitat. However,
extensive livestock grazing-related damage has occurred in the last
couple of years in some instances, and livestock grazing on private
lands where least chub occur is still partially unregulated. Therefore,
we conclude that current levels of livestock grazing are likely to
significantly threaten least chub populations at Leland Harris Spring
Complex, Gandy Salt Marsh, Bishop Springs Complex, and Mills Valley,
now and in the foreseeable future.
(2) Oil and Gas Leasing and Exploration
Oil and gas leasing and exploration can have direct and indirect
impacts on springs, marshes, and riparian habitats. Vehicles, including
drilling rigs and recording trucks, can crush vegetation, compact
soils, and introduce exotic plant species (BLM 2008, pp. 4-9 to 4-20).
Roads and well pads can affect local drainages and surface hydrology,
and increase erosion and sedimentation (Matherne 2006, p. 35).
Accidental spills (Etkin 2009, pp. 36-42, 56) can result in the release
of hydrocarbon products into ground and surface waters (Stalfort 1998,
section 1). Accumulations of contaminants in floodplains can result in
lethal or sublethal impacts to endemic sensitive aquatic species
(Stalfort 1998, section 4; Fleeger et al. 2003, p. 207).
All of the naturally occurring, extant least chub populations occur
within the Fillmore BLM area. The majority of BLM land in the Fillmore
Field Office is open to oil and gas leasing (BLM 2009a, p. 11). Oil and
gas leases have been sold within the watershed areas of most of the
naturally occurring least chub populations, but the closest active well
to a least chub population is currently 9.7 km (6 mi) away (Megown
2009a, entire). The Gandy Salt Marsh population area is closed to
leasing by BLM in accordance with the Fillmore Resource Management Plan
(RMP) because of the occurrence of least chub habitat. This RMP will be
updated in approximately 10 to 15 years. Any change to the management
direction would be reviewed at this time and subject to public comment
(BLM 2009a, p. 54). Seismic surveys were conducted on parcels adjacent
to the Mills Valley population, and BLM anticipates that a Notice of
Staking or Application for Permit to Drill may be filed by the lessee
in 2010 (Mansfield 2009, p. 1).
Based on past drilling history, the BLM's Fillmore Field Office
determined that recoverable oil and gas is likely to be of low
availability within the range of the least chub. They further estimated
that exploratory wells will be drilled at the rate of about one well
every year for the foreseeable future (BLM 2009a, p. 52). Leases near
least chub habitat will not be offered for sale until the Fillmore BLM
RMP is revised; the RMP revision is not yet scheduled (Naeve 2009a-c,
entire).
Oil and gas leases in the BLM Fillmore Field Office will include
lease notices with information on sensitive species and conservation
agreement species where appropriate (BLM 2009a, pp. 14, 98-99). These
lease notices include measures to coordinate with UDWR to minimize the
risk of spreading aquatic exotic species; avoid surface pumping for
water; avoid surface disturbances within 100-year floodplains; avoid
changes to ground and surface hydrology; and avoid direct disturbances
to special status species (BLM 2009a, pp. 98-99). The extent of
implementation of each lease notice, and the success of the lease
notices, will not be known until development occurs. However, the lease
notices in combination with the low energy development potential should
ensure that oil and gas development is not a significant threat to the
species in the
[[Page 35404]]
foreseeable future. Recoverable oil and gas across the entire Fillmore
Field Office area is expected to be low, with a rate of one exploratory
well drilled annually, and the nearest active well is 9.7 km (6 mi)
from an extant least chub population. We conclude that oil and gas
development are not anticipated to occur at a level that will threaten
least chub.
(3) Mining
Mills Valley contains a bog area with a peat and humus resource
(Olsen 2004, p. 6). Peat mining has the potential to alter the
hydrology and habitat complexity of Mills Valley, making it unsuitable
for least chub (Bailey et al. 2005, p. 31). An illegal peat removal
activity occurred on private lands in the Mills Valley wetlands in 2003
(Wilson 2009a, pers. comm.). The illegal activity was less than 0.2 ha
(0.5 ac) in size, and impacts to associated wetlands were restored
(Wilson 2009a, pers. comm.). In 2003, a Mills Valley landowner received
a permit from the Utah Division of Oil, Gas, and Mining to conduct peat
mining on their private land. Although one test hole was dug, no
further peat mining occurred in this location. This peat mining permit
is now inactive and noncompliant with State regulations requiring
payment of mining and bond fees (Wilson 2009a, pers. comm.). Past peat
mining activities have been unsuccessful in Mills Valley, and we are
unaware of any future private or commercial peat mining proposals.
In summary, our analysis found one illegal peat removal activity
and one abandoned attempt at legal peat removal in the Mills Valley
least chub population area. We are unaware of any additional private or
commercial peat operation proposals in Mills Valley. We conclude that
peat mining is not anticipated to occur at a level that will threaten
least chub.
(4) Urban and Suburban Development
Urban and suburban development affect least chub habitats through:
(1) Changes to hydrology and sediment regimes; (2) inputs of pollution
from human activities (contaminants, fertilizers, and pesticides); (3)
introductions of nonnative plants and animals; and (4) alterations of
springheads, stream banks, floodplains, and wetland habitats by
increased diversions of surface flows and connected groundwater (Dunne
and Leopold 1978, pp. 693-702).
The least chub was originally common throughout the Bonneville
Basin in a variety of habitat types (Sigler and Miller 1963, p. 82). In
many urbanized and agricultural areas, residential development and
water development projects have effectively eliminated historical
habitats and potential reintroduction sites for least chub (Keleher and
Barker 2004, p. 4; Thompson 2005, p. 9). Development and urban
encroachment have either functionally or completely eliminated most
springs, streams, and wetlands along the Wasatch Front (Keleher and
Barker 2004, p. 2).
The Mona Springs site, as well as potential reintroduction sites
(Keleher and Barker 2004, p. 4; Thompson 2005, p. 9) on the Wasatch
Front, are vulnerable to rapid population growth. The human population
in the Mona Springs area has increased 64.9 percent from 2000 to mid
2008 (City-Data 2009, p. 1) and a housing development has expanded to
within 1 km (0.6 mi) of the Mona Springs least chub site (Megown 2009b,
entire). The URMCC, which is responsible for mitigating impacts caused
by Federal reclamation projects to fish, wildlife, and related
recreation resources in Utah, has purchased and protected much of the
Mona Springs habitat areas for conserving least chub and spotted frog
populations (see Factor D). However, indirect effects of urban
development such as pollution from urban stormwater runoff and changes
to hydrologic sediment regimes (e.g., sedimentation from adjacent
construction activities) could negatively impact the aquatic habitats
at Mona Springs. Even if mosquitofish and other predacious nonnative
fish (the primary threat at this site) can be controlled in the future,
we believe urban-development-related effects could rise to a level that
may preclude reestablishment of a viable least chub population at Mona
Springs.
Despite the effects of urban and suburban development on historic
populations of least chub, we have no information indicating this is a
threat to the five remaining extant least chub populations. These least
chub populations occur in relatively remote portions of Utah with
minimal human populations. No information is available indicating the
level of human occupation near these sites. However, the population
centers nearest to extant least chub populations are more than 16 km
(10 mi) away and have populations of less than 3,000 persons (Utah
Governor's Office of Planning and Budget 2009, entire).
To summarize, development along the eastern portion of the least
chub historic range has contributed to the elimination of most of the
historic populations of least chub. The Mona Springs site is currently
the only site in this geographic area that still contains least chub,
but the population is functionally extirpated. We have no information
suggesting that future urban or suburban development will occur at a
level that will threaten least chub.
(5) Water Withdrawal and Diversion
Hydrologic alterations, including water withdrawal and diversion,
affect a variety of abiotic and biotic factors that regulate least chub
population size and persistence. Abiotic factors include physical and
chemical characteristics of the environment, such as water levels and
temperature, while biotic factors include interactions with other
individuals or other species (Deacon 2007, pp. 1-2). Water withdrawal
directly reduces available habitat, impacting water depth, water
surface area, and flows from springheads (Alley et al. 1999, p. 43). As
available habitat decreases, the characteristics and value of the
remaining habitat changes. Reductions in water availability to least
chub habitat reduce the quantity and quality of the remaining habitat
(Deacon 2007, p. 1).
Water withdrawal and diversion reduces the size of ponds, springs,
and other water features that support least chub (Alley et al. 1999, p.
43). Assuming that the habitat remains at carrying capacity for the
species or, in other words, assuming all population processes (birth
rate, death rate, etc.) remain unchanged, smaller habitats support
fewer individuals by offering fewer resources for the population
(Deacon 2007, p. 1).
Because least chub live in patchily distributed desert aquatic
systems, reduction in habitat size also affects the quality of the
habitat. Reduced water depth may isolate areas that would be
hydrologically connected at higher water levels. Within least chub
habitat, springheads offer stable environmental conditions, such as
temperature and oxygen levels, for refugia and overwintering, but offer
little food or vegetation (Deacon 2007, p. 2). In contrast, marsh areas
offer vegetation for spawning and feeding, but exhibit wide
fluctuations in environmental conditions (Crawford 1979, p. 63; Crist
and Holden 1980, p. 804). Maintaining hydrologic connections between
springheads and marsh areas is important because least chub migrate
between these areas to access the full range of their ecological
requirements (Crawford 1979, p. 63; Crist and Holden 1980, p. 804;
Lamarra 1981, p. 10).
Although we have not directly observed the effects of flow
reductions on wild least chub populations, we believe that flow
reductions will reduce the hydrology that supports wetland
[[Page 35405]]
and wetland/upland transition zones which, in turn, provide vegetation
needed for the least chub reproductive cycle (Crawford 1979, p. 38;
Lamarra 1981, p. 10). Alterations of natural flow processes also could
alter sediment transport processes that prevent vegetation encroachment
into sensitive spring areas (60 FR 50520).
Reductions in water may alter chemical and physical properties of
aquatic habitats. As water quantity decreases, temperatures may rise
(especially in desert ecosystems with little shade cover), dissolved
oxygen may decrease, and the concentration of pollutants may increase
(Alley et al. 1999, p. 41; Deacon 2007, p. 1). These modified habitat
conditions are likely to significantly impact least chub life history
processes, possibly beyond the state at which the species can survive.
The maximum growth rate for least chub less than 1 year of age would
occur at 22.3 [deg]C (72.1 [deg]F). Temperatures above or below this
have the potential to negatively impact growth and affect survival
rates (Billman et al. 2006, p. 438).
Reduced habitat quality and quantity may cause niche overlaps with
other fish species, increasing hybrid introgression, interspecific
competition, and predation (Deacon 2007, p. 2) (see Factor C.
Predation; Factor E. Hybridization). Reduction in flow of springs
reduces opportunities for habitat niche partitioning; therefore, fewer
species are able to coexist. The effect is especially problematic with
respect to introduced species. Native species may be able to coexist
with introduced species in relatively large habitats (see Factor C.
Predation), but become increasingly vulnerable to extirpation as
habitat size diminishes (Deacon 2007, p. 2).
Habitat reduction may affect the species by altering individual
success. Fish and other aquatic species tend to adjust their maximum
size to the amount of habitat available, so reduced habitat may reduce
the growth capacity of least chub (Smith 1981, in Deacon 2007, p. 2).
Reproductive output decreases exponentially as fish size decreases
(Deacon 2007, p. 2). Therefore, reduction of habitat volume in isolated
desert springs and streams reduces reproductive output (Deacon 2007, p.
2). Longevity also may be reduced resulting in fewer reproductive
seasons (Deacon 2007, p. 2).
Current Groundwater Pumping
The Utah State Engineer (USE), through the Utah Division of Water
Rights (UDWRi), is responsible for the administration of water rights,
including the appropriation, distribution, and management of the
State's surface and groundwater. This office has broad discretionary
powers to implement the duties required by the office. The USE's Office
was created in 1897, and the State Engineer is the chief water rights
administrative officer. For groundwater management, Utah is divided
into groundwater areas, and policy is determined by area (BLM 2009b,
entire).
A joint report by the U.S. Geological Survey (USGS) and several
State of Utah agencies provided a description of groundwater conditions
in the State of Utah for 2008 (Burden 2009, entire). Each of the
locations occupied by least chub had a corresponding summary by valley
or hydrographic area for: the number of wells constructed in 2008; the
total estimated groundwater withdrawn in the area for 2008; the total
estimated groundwater withdrawn for each year for the previous 10
years; and groundwater level monitoring results from several monitoring
wells for varying periods of record (~20 to 75 years). For all valleys
and hydrographic areas, the predominant (greater than 79 percent) use
of withdrawn groundwater was for irrigation with remaining uses
including industrial, public supply, domestic, and stock (Burden 2009,
pp. 5, 89).
The Juab Valley, where the Mona Springs least chub site is located,
had a total of two new wells, and 26,000 acre-feet per year (afy)
withdrawn for 2008 (Burden 2009, pp. 3-5). This is more than double the
amount withdrawn in 1998 (12,000 afy) and is an overall increase from
the 1998-2007 average (22,000 afy) (Burden 2009, p. 6). All supplies of
surface and groundwater are fully appropriated; however, new wells
could be developed with existing groundwater rights (UDWRi 2009d, pp.
1-2).
Although the Mills Valley population site did not have a
corresponding pumping area in the report, the Central Sevier Valley
summary represents pumping activity in the river valley upstream of
this population and may be indicative of the potential for groundwater
withdrawal effects. The Central Sevier Valley had a total of 13 new
wells, and 24,000 afy withdrawn in 2008 (Burden 2009, pp. 3-5). This is
4,000 afy more than the amount withdrawn in 1998 (20,000 afy) and is an
8,000-afy increase from the 1998-2007 average (16,000 afy) (Burden
2009, p. 6). Since 1997, the corresponding part of the Sevier River
Basin was closed to all new appropriations of groundwater. However, new
groundwater development can occur under existing groundwater rights
(UDWRi 2009d, pp. 3-4).
The Clear Lake least chub site is located within the Sevier Desert
groundwater pumping basin, which had 11 new wells with 44,000 afy
withdrawn in 2008 (Burden 2009, pp. 3-5). This is 32,000 afy more than
the amount of water withdrawn in 1998 (12,000 afy) and is a 20,000-afy
increase from the 1998-2007 average (24,000 afy) (Burden 2009, p. 6).
Since 1997, this part of the Sevier River Basin was closed to all new
appropriations of groundwater except for domestic filings not exceeding
1.0 acre-foot and for filings reviewed on an individual basis in
limited areas of the basin (UDWRi 2009d, pp. 5-6).
The Snake Valley summary, which corresponds to the pumping activity
in the vicinity of Leland Harris Spring Complex, Gandy Salt Marsh, and
Bishop Spring Complex did not report the number of new wells, but did
specify 19,800 and 20,200 afy withdrawn for 2007 and 2008,
respectively, in Utah (Burden 2009, p. 89). Additional information on
groundwater pumping over the last decade was not provided. State of
Nevada Division of Water Resources reported that 11,000 afy of
groundwater was pumped from the Nevada portion of Snake Valley in 2009
(NDWR 2009, entire). Groundwater is currently open to appropriation in
Snake Valley in Utah (UDWRi 2009d, pp. 7-9) and Nevada (NDWR 2009,
entire).
The previously discussed increases in groundwater pumping have
occurred at the same time that a declining trend in groundwater level
was observed at wells monitored in or very near basins with least chub
populations (Burden 2009, pp. 41-57, 89, 96). Groundwater monitoring
shows that water levels generally rose in the early to mid 1980s,
likely as a result of greater-than-average precipitation. However,
groundwater levels generally declined from the mid-to-late 1980s to the
present. Although drought conditions were present in the eastern Great
Basin (areas with extant least chub populations) during this time (See
Factor A. Drought), localized annual precipitation levels were either
average to slightly above average (Mona Springs and Mills Valley least
chub sites) or were generally increasing, if below average (Clear Lake
and Snake Valley least chub sites), during this same timeframe (Burden
2009, pp. 41-57, 89, 96).
For the four basins discussed above, a more specific analysis of
groundwater level fluctuations over the last decade (1998-2009)
provides some indication of the scope of change. Groundwater
[[Page 35406]]
levels from six monitoring wells in Juab Valley (where the Mona Springs
least chub site is located) declined an average of 6.1 meters (m) (20
feet (ft)) with declines ranging from 0.6 to 10.1 m (2 to 33 ft)
(Burden 2009, pp. 41-45). As stated above, groundwater monitoring in
Central Sevier Valley basin represents pumping activity and groundwater
levels in the river valley upstream of the Mills Valley least chub
population and may be indicative of the potential for groundwater
withdrawal effects. Groundwater levels in 10 monitoring wells in this
area declined an average of 0.9 m (3 ft) with declines ranging from 0
to 1.5 m (0 to 5 ft). Data from 15 monitoring wells in the Sevier
Desert groundwater pumping basin (where the Clear Lake least chub site
is located) indicated that groundwater levels declined an average of
2.4 m (8 ft) with declines ranging from 0.3 to 5.5 m (1 to 18 ft), and
groundwater monitoring levels in the Snake Valley (in the vicinity of
Leland Harris Spring Complex, Gandy Salt Marsh, and Bishop Spring
Complex) declined 1.2 m (4 ft) with declines ranging from 0.3 to 3 m (1
to 10 ft) (Burden 2009, pp. 46-52, 89-96).
We have limited information linking groundwater pumping to
decreases in flow at sites where least chub previously existed.
Agricultural pumping, combined with drought, has affected several
springs in Snake Valley. These include Knoll Spring near the town of
Eskdale and springs on private properties in the town of Callao (Sabey
2008, p. 2). These sites were all historically documented locations of
least chub that no longer harbor the species (Hickman 1989, pp. 16-17;
Garland 2007, pers. comm.).
Pumping for agricultural purposes, combined with the effects of
drought, has impacted flow in a number of springs in Snake Valley.
Although no least chub historically occurred at Needle Point Spring,
the BLM has detailed monitoring information linking nearby groundwater
pumping and its effect on the spring's flow. In 2001, the water level
at Needle Point Spring in Southern Snake Valley dropped to levels not
seen in 40 years (Summers 2008, pp. 1-2). This spring has a long
history of existence, identified as early as 1939 by the Civilian
Conservation Corps, when springflow was measured at 6 gallons per
minute (Summers 2008, p. 1). For the past several decades, the spring
was developed and used for watering livestock and wild horses (Summers
2008, p. 1). The 2001 decline in groundwater level at Needle Point
Spring was likely the result of, and coincides with, increased
irrigation in Hamlin Valley approximately 3.2 km (2 mi) west, and not a
result of the lowered precipitation (Summers 2008, p. 3).
Although the causal effect of groundwater pumping is unknown in the
following observations, UDWR has documented decreases in habitat at two
least chub sites. They recently reported decreases in least chub
habitat from springs drying and decreasing in size at the Clear Lake
least chub site (LCCT 2008b, p. 2). The UDWR found that annual drying
of some ponds with least chub is becoming a consistent trend resulting
in declining habitat quality, and is therefore limiting the
distribution of least chub at Clear Lake. Average water depth among
affected ponds decreased from 0.5 m (1.6 ft) in 2006 to 0.2 m (0.7 ft)
in 2008 (LCCT 2008b, p. 2). At the Gandy Salt Marsh site, least chub
populations have declined by more than 50 percent (from 1993 to 2006)
as a result of a reduction in available habitats due to the drying of
springs throughout the complex (Wilson 2006, p. 8).
As described above, current groundwater pumping levels have
increased in the last 10 years and in some locations have more than
doubled. Groundwater levels have decreased during this same time period
while precipitation levels were average or generally increasing if
below average. Negative impacts to least chub habitat were documented
at the same time this scenario was occurring. In addition, all basins
where least chub occur are currently open to additional groundwater
pumping. Therefore, we conclude that current levels of groundwater
pumping are likely to significantly threaten all least chub populations
now and in the foreseeable future.
Snake Valley has harbored the most secure least chub populations
over the past 50 years (Hickman 1989, p. 2; Hines et al. 2008, pp. 34-
45). As detailed in the following sections of this document, proposed
water development projects intend to transport water from the
underlying aquifers in the vicinity of Snake Valley. Projects include a
Southern Nevada Water Authority (SNWA) Groundwater Development (GWD)
Project, appropriation of groundwater by the Central Iron County Water
Conservancy District and Beaver County, Utah, and an increase of water
development by the Confederated Tribes of the Goshute Reservation.
These water withdrawals threaten to change the underlying hydrology of
the area and may modify least chub habitat and impact the extant
populations in the Snake Valley in the foreseeable future (see below
for more information).
Southern Nevada Water Authority Proposed Groundwater Development
Project
One of the most significant threats to extant least chub
populations may be proposed groundwater withdrawals from the Snake
Valley aquifer. Several applications for groundwater withdrawal from
the Snake Valley aquifer are pending (SNWA 2008, p. 1-6), and SNWA has
applied to the BLM for issuance of rights-of-way to construct and
operate a system of regional water supply and conveyance facilities
(SNWA 2008, p. 1-3). The SNWA GWD Project includes construction and
operation of groundwater production wells, water conveyance facilities,
and power facilities (SNWA 2008, p. 1-3). The proposed production wells
and facilities would be located predominately on public lands managed
by BLM (SNWA 2008, p. 1-3).
As proposed, the SNWA GWD Project would convey up to 170,000 afy of
groundwater from hydrographic basins in Clark, Lincoln, and White Pine
Counties, Nevada, to SNWA member agencies and the Lincoln County Water
Conservancy District (SNWA 2008, p. 1-1). Although all SNWA facilities
are planned for development in Nevada, associated pumping from the
Spring Valley and Snake Valley hydrographic basins (SNWA 2008, pp. 1-4,
Figures 1-2) is expected to affect Utah groundwater resources and
consequently habitats of the least chub (Welch et al. 2007, p. 82).
The SNWA would receive all groundwater conveyed from the Snake
Valley (approximately 50,679 afy) and Spring Valley (approximately
68,000 afy) Basins (SNWA 2008, p. 1-6, Table 1-1). The groundwater that
SNWA intends to convey would be from existing and future permitted
water rights (SNWA 2008, p. 1-6, Table 1-1). If all permits are
granted, SNWA intends to start pumping operations for Spring Valley in
2028 and Snake Valley in 2050 (BLM 2009, p. 2-12). As substantiated
below, the SNWA GWD project is likely to significantly threaten least
chub populations in the foreseeable future.
The Service has been concerned about impacts from this proposed
large-scale water withdrawal for many years. In 1990, the Service and
other Department of the Interior (DOI) agencies (BLM, National Park
Service, and Bureau of Indian Affairs) protested water rights
applications in Spring and Snake Valley, based in part on potential
impacts to water-dependent natural resources (Plenert 1990, p. 1;
Nevada
[[Page 35407]]
State Engineer (NSE) 2007, p. 11). In 2006, DOI agencies reached a
stipulated agreement with SNWA for the Spring Valley water rights
applications, withdrew their protests, and did not participate in the
NSE's hearing (NSE 2007, p. 11). For the Spring Valley portion of the
project, the Stipulated Agreement established a process for developing
and implementing hydrological and biological monitoring, management,
and mitigation for biological impacts (NSE 2007, p. 11).
To better understand the potential effects of the proposed large-
scale groundwater pumping, the NSE issued an October 28, 2008 order
(Interim Order No. 2 and Scheduling Order) in which the applicant
(SNWA) was required to provide a groundwater model that simulates
groundwater pumping and potential impacts from pumping in the amount of
10,000, 25,000, and 50,000 afy for the timeframes of 10, 25, 50, 100,
and 200 years. The NSE hearings on these applications were scheduled to
begin on September 28, 2009. These hearings were postponed based on a
pending agreement between the States of Nevada and Utah as described
below.
According to the Lincoln County Conservation, Recreation, and
Development Act (LCCRDA) of 2004 (LCCRDA 2004, entire), the States must
reach an agreement on the division of Snake Valley groundwater prior to
any transbasin groundwater diversions. Utah and Nevada have reached a
draft agreement that is still under discussion and not yet finalized
(Kikuchi and Conrad 2009, p. 3; Styler and Biaggi 2009, entire). As
drafted, the agreement preserves and protects existing water rights,
defines the available groundwater supply in Snake Valley as 132,000
afy, provides 41,000 afy of unallocated water to Utah and Nevada, and
monitors withdrawals to identify and avoid adverse impacts (Kikuchi and
Conrad 2009, p. 2).
To assist in developing this agreement, the LCCRDA required a study
of groundwater quantity, quality, and flow characteristics in the
carbonate and alluvial aquifers of White Pine County, Nevada;
groundwater basins located in White Pine or Lincoln Counties, Nevada;
and adjacent areas of east-central Nevada and western Utah (Welch et
al. 2007, p. iii). The USGS, the Desert Research Institute, and the
State of Utah conducted this Basin and Range Carbonate Aquifer System
(BARCAS) study. The USGS released a final report of the BARCAS study on
February 22, 2008 (Welch et al. 2007, entire).
The BARCAS study included a water-resources assessment of the
geologic framework and hydrologic processes influencing the quantity
and quality of groundwater resources. The USGS determined that
groundwater systems underlying many of the valleys in eastern Nevada
and western Utah are not isolated, but rather contribute to or receive
flow from adjoining basins (Welch et al. 2007, pp. 4-5). They also
determined that some large-volume springs cannot be supported entirely
by the local recharge from the adjacent mountains; these springs depend
on water from potentially hundreds of miles (kilometers) away (Welch et
al. 2007, p. 5).
Groundwater flows in a general direction from Spring Valley to
Snake Valley. Thus, large-scale pumping in Spring Valley is expected to
impact groundwater in Snake Valley. Current groundwater pumping in
Spring Valley was estimated at 18,475 afy in 2007 (NSE 2007, p. 35).
The additional 68,000 afy of groundwater pumping being proposed would
be a 368-percent increase in total groundwater pumped (NSE 2007, p.
56). The proposed total amount (86,475 afy) is 93 percent of the
estimated 93,000 afy annual natural recharge for the basin and 114
percent of the estimated 76,000-afy annual natural discharge of the
basin (Welch et al. 2007, p. 81).
Although current groundwater pumping for all of Snake Valley
(Nevada and Utah) was estimated at 35,000 afy in 2005, water rights are
currently allocated for 67,000 afy in Nevada (12,000 afy) and Utah
(55,000 afy) (Welch et al. 2007, p. 81; Kikuchi and Conrad 2009, p. 2).
An additional 41,000 afy of groundwater pumping is being proposed by
the States of Nevada and Utah in their interstate agreement. This
amount of additional groundwater pumping would be in place of the
50,679 afy that the SNWA project intends to pump, and would thus be a
61-percent increase in total groundwater allocated for pumping (SNWA
2008, pp. 1-6, Tables 1-1). The proposed total amount (108,000 afy) is
97 percent of the estimated 111,000-afy annual natural recharge for the
basin and 82 percent of the estimated 132,000-afy annual natural
discharge of the basin (Welch et al. 2007, p. 81; Kikuchi and Conrad
2009, p. 2).
The BARCAS study included assessments of the hydrogeology,
recharge, and discharge of groundwater flow and geochemistry of 13
hydrographic areas in eastern Nevada and western Utah, including the
Spring and Snake Valleys. The BARCAS study estimated that the study-
wide natural average annual groundwater recharge exceeded natural
annual discharge by about 90,000 afy (Welch et al. 2007, pp. 81-82).
However, factoring in human use of groundwater (80,000 afy) into this
estimate resulted in a nearly balanced groundwater budget over the
study area. Thus, future long-term use of groundwater at the current
level or any increased level (e.g., SNWA GWD project) could decrease
subsurface outflow and spring discharge in the foreseeable future
(Welch et al. 2007, p. 82). The study concluded that ``decreases in
outflow would be more likely in sub-basins having high pumping and
relatively large outflow, such as in Snake Valley'' (Welch et al. 2007,
p. 82). As explained in the previous section (Current Groundwater
Pumping), decreases in flow to some springs have already occurred in
Snake Valley.
In addition to the BARCAS study, in 2007 the Utah State Legislature
charged the Utah Geological Survey with conducting a 2-year study (West
Desert Groundwater Monitoring Project) to characterize the background
water levels and chemistry; understand regional flow in the carbonate
and basin-fill aquifer systems and their connectivity; quantify future
groundwater drawdowns; and collect data for future groundwater-flow
models (UGS 2008, entire). The groundwater monitoring network in Utah's
west desert should better define background water levels and
geochemical conditions prior to SNWA pumping, and also be able to help
quantify changes after pumping begins.
A lack of information exists on the extent of the aquifers, their
hydraulic properties, and the distribution of water levels that would
contribute to a reliable prediction of the amount or location of
drawdown, or the rate of change in natural discharge, caused by pumping
(Prudic 2006, p. 3). Despite the lack of site-specific information, we
can reasonably expect that additional groundwater withdrawal in Spring
and Snake Valleys will directly reduce spring discharge through reduced
flows from the shallow basin-fill aquifer or through reduction of the
hydraulic head of the deep carbonate aquifer (Welch et al. 2007, p.
82). As those flows become increasingly disconnected, habitats lose
characteristics essential to aspects of complex lifecycles,
particularly the reproductive requirements of least chub (Deacon 2007,
p. 3). Increases in groundwater use above the 2005 levels could
significantly alter the hydrology in areas surrounding least chub
habitat (Welch et al. 2007, p. 82).
The extent and timing of these effects will vary among springs,
based on their distance from extraction sites and
[[Page 35408]]
location relative to regional groundwater flow paths (Patten et al.
2007, pp. 398-399). Some, and maybe all, predictions of detrimental
impacts to the Snake Valley Hydrographic Basin from groundwater pumping
are likely to occur (Kirby and Hurlow 2005, p. 33) and are likely to
significantly threaten, and possibly eliminate, the remaining least
chub populations in Snake Valley in the foreseeable future.
Prior to the completion of the SNWA GWD Project, baseline data
collection and research on biologic and hydrologic impacts will
continue. Federal, State, and county government agencies, as well as
nongovernmental organizations and private interests, maintain a high
level of concern regarding negative impacts to spring discharge rates,
and ultimately least chub habitats, from groundwater pumping.
Other Proposed Water Development Projects
In addition to SNWA, other municipalities are interested in
developing water resources in areas that are potentially hydrologically
connected to least chub habitat. The following information is provided
to characterize the additional potential threat of groundwater
development, but does not at this time represent a clear threat to
least chub or their habitat. Actual effects will, in part, be dependent
on the degree of connectivity of water developments to least chub
habitats.
On October 17, 2006, the Central Iron County (Utah) Water
Conservancy District filed applications to appropriate underground
water in Hamlin Valley, Pine Valley, and Wah Wah Valley in the amounts
of 10,000, 15,000, and 12,000 afy, respectively (UDWRi 2009a, pp. 2,
12, 23). The principal use of this applied-for water is municipal, with
minor amounts used for stock watering (UDWRi 2009a, entire). To date,
the USE has not acted upon these applications. Similarly, Beaver
County, Utah, purchased water right applications in 2007 originally
filed on October 6, 1981, for Wah Wah, Pine, and Hamlin Valleys (UDWRi
2009b, pp. 2, 5, 8). A hearing was held on December 10, 2008, on these
Beaver County (successor-in-interest) applications, and on September
14, 2009, these water rights were rejected by the State Engineer (UDWRi
2009b, pp. 3, 6, 9). Lastly, the State of Utah School and Institutional
Trust Lands Administration (SITLA) filed applications for up to 9,600
afy from underground water wells in the Snake Valley (UDWRi 2009c,
entire). These water rights all occur in areas that are hydrologically
connected to Snake Valley and, thus, utilization of this water could
impact least chub habitat.
The Confederated Tribes of the Goshute Reservation, located in
east-central Nevada (White Pine County) and west-central Utah (Juab and
Tooele Counties) is interested in developing their as yet unused water
rights. They have a 1905 decreed surface water right along the Deep
Creek system in Utah (Steele 2008, p. 2), and are currently planning to
increase Deep Creek basin rights to provide for community development
projects (Steele 2008, p. 3). They estimate that up to 50,000 afy will
be needed for beneficial uses including expanded crop and livestock
irrigation, fishery management, surface water reservoir operation and
maintenance, and water pipeline conveyance (Steele 2008, p. 3). The USE
is currently reviewing their application to develop 50,000 afy of water
from the Deep Creek Valley.
To conclude, we assessed the threat of water withdrawal and
diversion by analyzing available information on historic, current, and
planned future groundwater development. It is clear that historic and
current groundwater withdrawal has impacted least chub and caused
population extirpations. Future water withdrawals are a significant
threat to extant populations. Local agriculture pumping and drought
have historically and are currently diminishing springs and least chub
habitats in Snake Valley. Many historic springs are permanently dry,
largely because of historic groundwater withdrawal. New wells are being
drilled on a yearly basis, and the amount of groundwater withdrawal is
generally increasing.
In 2008, the NSE approved a major portion of the SNWA groundwater
rights applications for the Spring Valley Hydrographic Basin. Current
active applications for groundwater withdrawals in areas supporting
least chub include SNWA applications in Snake Valley, and potential
projects by Central Iron County Water Conservancy District, Beaver
County, Utah, and the Confederated Tribes of the Goshute Reservation.
Because of the complexities of determining groundwater budgets and the
effects of future pumping, it is not possible at this time to determine
the degree to which least chub habitats would be affected by
groundwater pumping. However, information on current groundwater
pumping indicates that groundwater levels are generally decreasing in
basins or hydrographic areas with least chub, and that future large-
scale groundwater pumping in or near the Snake Valley populations of
least chub is predicted to result in decreased subsurface outflow and
spring discharge in Snake Valley.
The Snake Valley contains the only remaining naturally occurring
and relatively secure populations of least chub. Our analysis indicates
that groundwater withdrawals will continue to increase in the future
and lead to a decrease in suitable habitat for least chub; this is a
significant threat to the species, now and in the foreseeable future.
(6) Drought
Prolonged droughts have primary and secondary effects on
groundwater resources. Decreased precipitation leads to decreased
recharge of aquifers. Decreased surface-water resources generally lead
to increased groundwater withdrawal and increased requests for water-
well construction permits (Hutson et al. 2004, p. 40; Burden 2009, p.
2). Past and future climatic conditions (See Factor E. Climate Change)
influence the water available to both water development and aquatic
habitats, with water development usually taking priority.
The impacts to least chub habitat from drought can include:
reduction in habitat carrying capacity; lack of connectivity resulting
in isolation of habitats and resources; alteration of physical and
chemical properties of the habitat, such as temperature, oxygen, and
pollutants; vegetation changes; niche overlap resulting in
hybridization, competition, and predation; and reduced size and
reproductive output (Alley et al. 1999, pp. 41, 43; Deacon 2007, pp. 1-
2). These impacts are similar to those associated with water withdrawal
and diversions as described in Factor A.
Recently, the Utah and Nevada portions of the Great Basin
experienced drought conditions from 1999 until 2004 (Lambert 2009,
pers. comm.; NDMC 2009, entire). The recent drought is not unusual for
its length, but is for its severity; water year 2002 will be recorded
as one of the driest years on record for many parts of the Great Basin
(Lambert 2009, pers. comm; NDMC 2009, entire).
Although it is not possible to separate the effects of drought from
the effects of water withdrawal in order to analyze each separately as
a threat to the least chub, the cumulative impacts of both threats have
impacted least chub populations in the past. The cumulative impact of
drought and water development for irrigation has led to the loss of
springs in the Snake Valley, including those on the Bagley and Garland
Ranches (Garland 2007, pers. comm.). More recently, a multiyear
[[Page 35409]]
drought from 1999 to 2004 (Lambert 2009, pers. comm.; NDMC 2009,
entire) impacted least chub habitats, such as the Gandy Salt Marsh
(Wilson 2006, p. 8). At this site, UDWR observed the reduction of least
chub habitat from springs drying up throughout the complex (Wilson
2006, p. 8).
Although least chub have survived for thousands of years with
intermittent natural drought conditions, recent human settlement has
exacerbated drought conditions via human water use (Hutson et al. 2004,
p. 2). On its own, drought is not considered a significant threat to
the species as this is a natural condition with which least chub
evolved. However, the documented extirpation and population reductions
of least chub caused by drought and groundwater withdrawal, and plans
for future large-scale groundwater withdrawal, lead us to conclude that
drought is a significant threat to least chub.
Conservation Agreements
The LCCAS is the guiding document for management of least chub
(Bailey et al. 2005, entire) by the multiagency LCCT. Signatories to
the LCCAS include UDWR, the Service, BLM, BOR, URMCC, the Confederated
Tribes of the Goshute Reservation, CUWCD, and SNWA (Bailey et al. 2005,
p. 2). The LCCAS and the LCCT provide expertise, recommendations, and
coordination of funding for the conservation of the species, but do not
provide regulatory protection. In 1999, we withdrew a proposed rule to
list the least chub after analyzing the LCCAS and determining that the
conservation actions contained within afforded greater protection to
the least chub and rendered the existing regulatory mechanisms
adequate. We revisit that determination here.
Numerous conservation actions implemented through the LCCAS were
most recently summarized by UDWR (Hines et al. 2008, entire). Annual
surveys and monitoring of least chub have occurred since at least 1998
across the species' historic range. These surveys resulted in the
discovery of two new populations of least chub at Mills Valley and
Clear Lake. In addition, the surveys resulted in identification of a
few suitable reintroduction sites and the establishment of refuge
populations (as discussed in the ``Translocations'' section above).
Research efforts initiated and directed by the LCCAS have improved our
knowledge of least chub life history and genetic structure (Mock and
Miller 2005, p. 276; Mock and Bjerregaard 2007, p. 146). The LCCT was
successful in securing land acquisitions, easements, and water rights
to partially protect least chub populations and habitats at Mona
Springs, Bishop Springs, and Gandy Salt Marsh. Habitat enhancement
projects have focused on nonnative vegetation removal, grazing
management, and springhead and pond restorations. Efforts are ongoing
to control the impacts of nonnative aquatic species, such as
mosquitofish, but to date these methods have been largely unsuccessful
(for further discussion of nonnative species see Factor D below).
The LCCAS has proved invaluable in providing better information
concerning the least chub's status and distribution, and implementation
of research under the LCCAS has increased our understanding of least
chub life history, genetics, and interactions with invasive species
(Hines et al. 2008, entire). The LCCT has addressed several of the
factors previously thought to threaten the least chub and has made
substantial progress on the threat of grazing and direct habitat loss,
as well as the conservation of least chub genetics. However, the
participants signatory to the Agreement have no ability to protect the
least chub from the primary threat of loss of habitat due to
groundwater development and only limited ability to protect the species
from the threat of nonnative fish introduction (Hines et al. 2008,
entire). Limitations of the LCCAS and its participants also include
their ability to manage livestock grazing on private and SITLA lands.
Summary of Factor A
At this time, based on best available information, we do not
believe that mining, and oil and gas leasing and exploration, or urban
and suburban development significantly threaten least chub now or in
the foreseeable future. However, loss of habitat has extirpated least
chub from all but a fraction of its historical range primarily as a
result of development along the Wasatch Front and water diversions
throughout the Bonneville Basin. Remaining least chub populations are
threatened by livestock grazing (excluding the Clear Lake site) and
development of water resources for agricultural practices and urban
development. We find that listing the least chub as a threatened or
endangered species is warranted due to livestock grazing; water
withdrawal and diversion; and drought occurring now and in the
foreseeable future.
Habitat at four of the five extant populations of least chub is
currently impacted by livestock grazing. Although fencing and limited
livestock grazing management have reduced or eliminated many of the
negative impacts associated with this practice, impacts to least chub
habitat continue to result from livestock grazing on private lands or
in areas where livestock grazing is uncontrolled for short periods of
time. Grazing impacts continue to occur on an intermittent basis at
Leland Harris Spring Complex, Gandy Salt Marsh, Bishop Springs Complex,
and Mills Valley.
Three of the five extant populations of least chub persist in close
proximity to one another in the Snake Valley and occur within the same
groundwater basin, where they depend on springs and associated
wetlands. Additional significant groundwater development is expected to
occur by 2028 for Spring Valley and 2050 for Snake Valley with the
possibility of subsequent landscape-level effects to Snake Valley and
remnant least chub populations.
It is difficult to predict the foreseeable future regarding large-
scale groundwater withdrawal and resultant effects to least chub. We
expect that there may be a lag time after pumping commences before
effects will be realized by the species or measured by scientists.
Because the agreement that would manage groundwater allocations in
Snake Valley is still in draft form, the groundwater hydrology of the
Snake Valley is not well known, and the area is already experiencing
changes in water regime due to the effects of water withdrawal,
drought, and climate change, we cannot confidently predict when impacts
from water withdrawals will occur.
Therefore, we find the least chub is threatened by the present or
threatened destruction, modification, or curtailment of the species'
habitat or range, now and in the foreseeable future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes.
Commercial, recreational, scientific, and educational utilizations
are not common least chub related activities, and protections are in
place to limit their effect on the species. Least chub are considered a
``prohibited'' species under Utah's Collection Importation and
Possession of Zoological Animals Rule (R-657-3-1), which makes it
unlawful to collect or possess least chub without a permit. Over the
past 8 years only two permits were issued by UDWR for survey of least
chub in the wild. All fish collected for these studies were released
unharmed (Wilson 2009b, p. 1). Use of least chub for scientific or
educational purposes also is controlled by UDWR, and the agency
typically provides least chub from fish hatchery stocks for these
purposes (Wilson 2009b, pp. 1-4.). The UDWR has collected least chub
from the
[[Page 35410]]
wild (an average of 334 per year combined for all extant populations
for the last 10 years) to augment hatchery stocks or for transfer to
new or existing translocation sites (Wilson 2009b, pp. 2-3). We are
aware of no evidence that least chub are being illegally collected for
commercial or recreational purposes.
Summary of Factor B
Least chub are not being overutilized for commercial, recreational,
scientific, or educational purposes. Fish that are needed for research
purposes can be provided from fish hatchery stocks. A limited number of
least chub have been collected from wild populations for hatchery
augmentation or for translocation purposes, but we have no information
to suggest that this causes a threat to extant populations now or in
the foreseeable future. We find that overutilization for commercial,
recreational, scientific, or educational purposes of the least chub is
not a threat now or in the foreseeable future.
C. Disease or Predation.
Predation
Least chub rarely persist where nonnative fishes have been
introduced (Osmundson 1985, p. 2; Hickman 1989, pp. 2-3, 9). The
species is tolerant of broad natural habitat conditions and is well
adapted to persist in the extreme, yet natural, environments of springs
and playa marshes of the Bonneville Basin, but they are not an
effective competitor with nonnative species (Lamarra 1981, p. 1), and
are constantly threatened by the introduction and presence of nonnative
fish (Hickman 1989, p. 10).
The mosquitofish is the most detrimental invasive fish to least
chub (Perkins et al. 1998, p. 23; Mills et al. 2004b, entire).
Mosquitofish predate on the eggs and the smaller size classes of least
chub and compete with adults (Mills et al. 2004b, p. 713). The presence
of mosquitofish changes least chub behavior and habitat use because
young least chub retreat to heavily vegetated, cooler habitats in an
effort to seek cover from predation. In these less optimal
environments, they have to compete with small mosquitofish that also
are seeking refuge from adult mosquitofish. This predatory refuge
scenario, in turn, affects survivorship and growth of least chub young
of year (Mills et al. 2004b, pp. 716-717).
Mosquitofish tolerate an extensive range of environmental
conditions and have high reproductive potential (Pyke 2008, pp. 171,
173). The ecological impact of introduced mosquitofish is well
documented. Mosquitofish profoundly alter ecosystem function, and
several studies have demonstrated their effects on the decline of
native amphibians and small fish (Alcaraz and Garcia-Berthou 2007, pp.
83-84; Pyke 2008, pp. 180-181). The mosquitofish is native only to the
southern United States and northern Mexico, but has been introduced
into more than 50 countries (Garc[iacute]a-Berthou et al. 2005, p. 453)
to control mosquito populations and malaria (Pyke 2008, p. 172).
Mosquito abatement districts throughout Utah have released
mosquitofish for mosquito control since 1931 (Radant 2002, p. 2). The
mosquitofish have expanded into aquatic ecosystems throughout Utah
(Sigler and Sigler 1996, pp. 227-229). Despite extensive efforts that
include chemical poisoning and mechanical removal, the elimination of
mosquitofish from least chub habitats has not been successful.
Mosquitofish have contributed to the functional extirpation of least
chub populations at the naturally occurring Mona Springs site (Hines et
al. 2008 pp. 35-37), and contributed to the extirpation of least chub
at three translocation sites including Walter and Deadman Springs at
Fish Springs National Wildlife Refuge (Wilson and Whiting 2002, p. 4),
and at an Antelope Island pond (Thompson 2005, pp. 5-6).
The UDWR implemented a Memorandum of Agreement (MOA) with Mosquito
Abatement Districts in an effort to reduce the continued spread of
mosquitofish (Radant 2002, entire). The MOA established administrative
processes and procedures for collecting, holding, propagating,
transporting, distributing, and releasing mosquitofish for signatory
mosquito abatement districts. Mosquito abatement districts that did not
sign the MOA are prohibited from engaging in any mosquitofish-related
activities (Radant 2002, p. 1). The MOA restricts the use of
mosquitofish to locations approved by the UDWR (Radant 2002, p. 5). The
MOA was established to function in perpetuity, but any party to the
agreement can terminate their involvement by providing 60 days' written
notice to the UDWR. Termination by one or more parties will not act to
terminate the agreement to other parties. Once a signatory terminates
their involvement in the MOA, they are prohibited from engaging in any
mosquitofish activities (Radant 2002, p. 7). This policy is not
expected to change in the foreseeable future.
Other nonnative fishes predate upon and compete with least chub.
Rainwater killifish (Lucania parva) and plains killifish (Fundulus
zebrinis) have been illegally introduced into least chub habitats by
unknown entities (Perkin et al. 1998, p. 23). These fish are potential
competitors with the least chub because they are closely related to
mosquitofish and have similar life histories and habitat requirements
(Perkins et al. 1998, p. 23).
Introduced game fishes, including largemouth bass (Micropterus
salmoides), rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus
carpio), and brook trout (Salvelinus fontinalis) are predators of least
chub, and these species are present in both native and introduced least
chub habitats (Workman et al. 1979, pp. 1-2, 136; Osmundson 1985, p. 2;
Sigler and Sigler 1987, p. 183; Crist 1990, p. 5). Clear Lake and Mills
Valley least chub populations are currently sympatric with nonnative
predators other than mosquitofish. Rainbow trout and common carp are
present in Clear Lake (Hines et al. 2008, p. 43). Clear Lake is an
expansive habitat that allows least chub to temporarily coexist with
nonnative fishes, but least chub will become increasingly vulnerable to
extinction if habitat size diminishes (Deacon 2007, p. 2) or nonnative
numbers increase. Nonnative sunfish (Lepomis sp.), which is a voracious
predator, and fathead minnow (Pimephales promelas) (Sigler and Sigler
1987, p. 306), are established at the Mills Valley site and are
increasing in number (Hines et al. 2008, p. 43).
In summary, least chub are unlikely to persist indefinitely in the
presence of nonnative species, particularly mosquitofish. Mosquitofish
are a predator of least chub eggs and young, and they compete with
least chub for food items. The presence of nonnative predacious fish
results in the decline and eventual elimination of least chub
populations. The stocking of mosquitofish into least chub habitat by
Statewide mosquito abatement programs has been addressed by an MOA that
regulates this practice. Removing mosquitofish from aquatic habitats
has not been successful, and they continue to invade new sites. Four
naturally occurring or introduced least chub populations have been
extirpated by mosquitofish (Hines et al. 2008 pp. 35-37; Wilson and
Whiting 2002, p. 4; Thompson 2005, pp. 5-6). These include the sites of
Deadman and Walter springs, Antelope Island, and Mona Springs. Two of
the five remaining least chub populations (Mills Valley and Clear Lake)
are coexisting with nonnative species. Therefore, we determine that the
continued existence of least chub is threatened by the presence of
nonnative fish species and their potential spread into least chub
[[Page 35411]]
habitat. This threat will become exacerbated in the future by any
reductions in water quantity that further fragment and degrade the
habitat.
Disease and Parasitism
Disease and parasitism have not affected least chub to a
significant degree. Workman et al. (1979, pp. 2, 103-107) found the
parasite blackspot (Neascus cuticola) present in the least chub
population at the Leland Harris Spring Complex site during 1977-78
sampling, and at the time determined that all least chub examined
appeared robust and in good condition. More recently, the parasite was
identified in least chub at the Bishop Springs site by Wheeler et al.
(2004, p. 5). Although we have no information that allows us to
determine the effect of blackspot on least chub at the Bishop Springs
site, monitoring over the past 14 years indicates that the population
has remained stable (Hines et al. 2008, pp. 37-39).
The exotic snail Melanoides tuberculata is an intermediate host and
vector for parasites known to be dangerous to humans, livestock, and
wild animals, including threatened endemic fishes and amphibians (Rader
et al. 2003, p. 647). M. tuberculata occurs at the Bishop Springs and
Clear Lake sites, but we do not have any information that links this
snail species to parasites that are harmful to least chub (Rader et al.
2003, p. 649). M. tuberculata appears to be restricted by water
temperature, but has the potential to be found in other least chub
habitats in the future, because sampling for M. tuberculata has not
occurred at all known least chub sites (Rader et al. 2003, pp. 650-
651).
In 2006, least chub from the Leland Harris Spring Complex
population were subjected to a disease-check regimen at the Fisheries
Experiment Station in Logan, Utah. Eight different parasites were
detected on the fish; however, it was the opinion of LCCT that the
presence of these parasites is common on a seasonal basis for most wild
populations of least chub (Wilson 2009b, p. 4). Considering that least
chub are the dominant fish species at the Leland Harris Spring Complex
site and that their population appears stable (Hines et al. 2008, p.
42), these diseases are likely having a minimal effect on the species.
Although parasites exist in least chub habitats, and some least
chub have been found to harbor parasites, we do not have evidence that
individual least chub or least chub populations are significantly
compromised or threatened by the presence of parasites.
Summary of Factor C
At this time, we know of no information that indicates that the
presence of parasites or disease significantly affects least chub, now
or in the foreseeable future.
There is strong evidence that least chub are threatened by the
presence of nonnative fish species in their habitats. Populations of
least chub that are sympatric with nonnative fish have become
extirpated or functionally extirpated, and extant populations generally
decline when in the presence of nonnative fish, especially
mosquitofish. The MOA with the mosquito abatement districts is a
positive step toward prohibiting the spread of mosquitofish in least
chub habitats. Although hatchery stocks provide a source for
reintroductions, removal of nonnative fish has not been successful;
sites previously used for translocation sites have had limited success;
and very few new sites that are appropriate for least chub
introductions are available. Based on the best scientific and
commercial information available to us, we conclude that nonnative fish
predation of least chub is a threat to the continued existence of the
species, now and in the foreseeable future.
D. Inadequacy of Existing Regulatory Mechanisms
The Act requires us to examine the adequacy of existing regulatory
mechanisms with respect to extant threats that place least chub in
danger of becoming either threatened or endangered. Regulatory
mechanisms affecting the species fall into four general categories: (1)
Land management, (2) State mechanisms, (3) Federal mechanisms, and (4)
conservation agreements.
(1) Land Management
Wild populations of least chub are distributed across private, BLM,
SITLA, and State UDWR lands and incur varying regulatory mechanisms
depending on land ownership.
(1) Mona Springs: Habitat in the vicinity of Mona Springs was
primarily private land (Wilson 2009c, pers. comm.). However, the URMCC
acquired 34.6 ha (85.5 ac) in 1998 and 7.2 ha (17.7 ac) in 2006 for the
protection of least chub and Utah State sensitive species the Columbia
spotted frog (Rana lutreiventris) (Hines et al. 2008, p. 34). The URMCC
has recently purchased and protected an additional 44.5 ha (18 ac) of
land on the north end of the spring complex (Wilson 2009c, pers.
comm.). The amount of habitat owned and managed by URMCC provides
protection from direct habitat loss. However, land ownership by URMCC
cannot protect the springs from loss of water caused by groundwater
pumping or from the threat of nonnative fish that are now at this site.
(2) Leland Harris Spring Complex: Land ownership for least chub
occupied habitat is primarily private although there also has been
occupied habitat on nearby SITLA and BLM land (Hines et al. 2008, pp.
41-42; Jimenez 2009, pers. comm.; Wilson 2009c, pers. comm.). Miller
Spring (located in this complex) and surrounding wetlands
(approximately 20.2 ha (50 ac)) are protected through a conservation
easement between UDWR and a private landowner. This level of land
management provides some protection through cooperative grazing
management under the conservation easement; however, impacts resulting
from livestock grazing still occur (see Factor A. Livestock Grazing).
There also is some protection provided through Federal land management
under the BLM RMP and future energy lease notices (See Factor A.
Mining, and Oil and Gas Leasing and Exploration). However, existing
land management does not protect the site from loss of water due to
groundwater pumping or the possibility of nonnative fish invasion. We
are unaware of any land management protection mechanisms on SITLA
lands.
(3) Gandy Salt Marsh: Land ownership includes BLM, SITLA, and
private lands (Wilson 2009c, pers. comm.). The BLM has designated 919
ha (2,270 ac) as an Area of Critical Environmental Concern (ACEC) that
is closed to oil and gas leasing to protect the least chub. The ACEC
includes most of the lake bed and aquatic habitats and is fenced to
exclude livestock (BLM 1992, pp. 11, 16, 18). This level of land
management is adequate to protect the site from human-caused impacts
associated with energy development and livestock grazing on Federal
lands, but does not protect the habitat on SITLA or private lands. In
addition, there is not protection from the loss of water due to
groundwater pumping or the possibility of nonnative fish invasion.
(4) Bishop Springs Complex: Land ownership is primarily private,
but includes SITLA and BLM lands (Wilson 2009c, pers. comm.). In 2006,
UDWR purchased water rights from the landowner for Foote Reservoir and
Bishop Twin Springs (a.k.a. Bishop Small Springs) (Wilson 2009c, pers.
comm.). These water bodies provide most of the perennial water to the
[[Page 35412]]
complex (Hines et al. 2008, p. 37). In 2008, UDWR obtained a permit for
permanent change of use from the USE for instream flow according to a
seasonal schedule. This instream flow helps to maintain water levels at
Bishop Springs Complex, protecting the least chub and Columbia spotted
frog populations (Hines et al. 2008, p. 37). The UDWR-owned instream
flow water rights may protect least chub populations in this area from
loss of water due to existing private landowner uses. However, this
level of land management cannot protect for the possibility of
nonnative fish invasion or impacts associated with livestock grazing on
private lands, and it may not be adequate to protect the site from the
indirect loss of water associated with future large-scale groundwater
pumping. We are unaware of any land management protection mechanisms on
SITLA lands.
(5) Mills Valley: Most of the Mills Valley site is privately owned,
and no management agreements are in place. The UDWR is working with
landowners to improve the current grazing management plans (Hines et
al. 2008, p. 43). Approximately 36.4 ha (90 ac) is owned by UDWR as the
Mills Meadow WMA (Wilson 2009c, pers. comm.). Livestock grazing rights
at this WMA are awarded to adjacent landowners in exchange for public
and UDWR access to their property (Stahli and Crockett 2008, p. 5). The
limited amount of habitat owned by UDWR provides some protection from
direct habitat loss and other direct human-caused impacts, and UDWR's
efforts to work with private landowners may provide protection on some
private land. However, this level of land management cannot protect the
area from all impacts associated with livestock grazing (see Factor A.
Livestock Grazing), loss of water caused by groundwater pumping, or
from the threat of nonnative fish that are now at this site.
(6) Clear Lake: This population occurs on the Clear Lake WMA, which
is managed by UDWR (Wilson 2009c, pers. comm.). The land owned and
managed by UDWR provides protection from direct habitat loss associated
with human land-uses, including livestock grazing. However, this level
of land management cannot protect the area from loss of water caused by
groundwater pumping or from the threat of nonnative fish that are now
at this site.
(2) State Mechanisms
Least chub are considered ``prohibited'' species under the Utah
Collection Importation and Possession of Zoological Animals Rule (R-
657-3-1), making them unlawful to collect or possess. These species
receive protection from unauthorized collection and take. While its
classification is not a regulatory mechanism, the least chub is
classified in the State of Utah Wildlife Action Plan as a Tier 1
Sensitive Species, a status that includes federally listed species and
species for which a conservation agreement has been completed and
implemented (Bailey et al. 2005, p.3). This classification includes
species for which there is credible scientific evidence to substantiate
a threat to continued population viability.
Introduced nonnative fishes for mosquito abatement and game-fishing
purposes can be detrimental to the persistence of least chub (see
Factor C. Predation). The UDWR follows their Policy for Fish Stocking
and Transfer Procedures and no longer stocks nonnative fish into least
chub habitat (Hines et al. 2008, p. 25). This Statewide policy
specifies protocols for the introduction of nonnative species into Utah
waters and states that all stocking actions must be consistent with
ongoing recovery and conservation actions for State of Utah sensitive
species, including least chub. This policy is not expected to change in
the foreseeable future.
Mosquito abatement districts are not prohibited from spraying least
chub habitat to control for mosquitoes. This practice has the potential
to reduce least chub prey items, and it may negatively affect potential
reintroduction sites. The BLM has rejected a Juab County (location of
Mills Valley and Leland Harris Springs Complex least chub populations)
request to implement a mosquito-control spraying program in marsh and
spring areas on BLM-administered lands; however, this does not prevent
the county from spraying on privately owned lands (Perkins et al. 1998,
p. 24).
In summary, abatement districts may be having an effect on least
chub populations by spraying to reduce mosquito larvae. On the basis of
the information we have at this time, we do not believe that mosquito
spraying is having a significant effect on least chub at an individual
or population level. As a result, we do not find that it is a
significant threat to the species.
The State of Utah operates under guidelines to prevent the movement
of aquatic invasive species, including quagga mussels (Dreissena sp.),
zebra mussels (Dreissena sp.), and mud snails (Potamopyrgus sp.) during
fish transfer operations (UDWR 2009, entire). Protocols include
notification and evaluation of water sources being considered for fish
transfers, fish health inspections, and completion of an updated Hazard
Analysis and Critical Control Point Plan. These protocols should help
reduce the probability of additional aquatic invasive species
introductions to least chub habitats.
Regulatory mechanisms that relate to historic groundwater
withdrawal are implemented through the USE through the UDWRi, the
Lincoln County Water Conservancy District, and the Central Iron County
Water Conservancy District as described in Factor A. Water Withdrawal
and Diversion section. Groundwater withdrawal in the Snake Valley for
future municipal development is subject to both Federal and State
regulatory processes. The LCCRDA directed a study of groundwater
quantity, quality, and flow characteristics in Utah and Nevada
counties, and the Utah State Legislature requested a study on
groundwater recharge and discharge to better determine effects of
planned groundwater withdrawal. The SNWA may begin pumping groundwater
for a portion of their proposed projects prior to completion of the
study that will help better disclose effects of the action. A lack of
data on effects of groundwater withdrawal to least chub is a concern,
and the ability of water districts to effectively manage groundwater to
avoid impacts to least chub populations has not been demonstrated. (See
Factor A. Water Withdrawal and Diversion for more detail.) Therefore,
we find that the State regulatory mechanisms in existence do not
adequately protect the least chub from the threat of reduction of
habitat due to water development projects.
(3) Federal Mechanisms
The major Federal mechanisms for protection of least chub and its
habitat are through section 404 of the Clean Water Act (33 U.S.C. 1251
et seq.) permitting process and the National Environmental Policy Act
(42 U.S.C. 4231 et seq.) (NEPA). Various Executive Orders (11990 for
wetlands, 11988 for floodplains, and 13112 for invasive species)
provide guidance and incentives for Federal land management agencies to
manage for habitat characteristics essential for least chub
conservation.
The primary Federal land management entity across the range of
extant least chub populations is the BLM. The least chub is designated
as a sensitive species by the BLM in Utah. The policy in BLM Manual
6840-Special Status Species Management states: ``Consistent with the
principles of
[[Page 35413]]
multiple use and in compliance with existing laws, the BLM shall
designate sensitive species and implement species management plans to
conserve these species and their habitats and shall ensure that
discretionary actions authorized, funded, or carried out by the BLM
would not result in significant decreases in the overall range-wide
species population and their habitats'' (BLM 2008, p. 10).
The NEPA has a provision for the Service to assume a cooperating
agency role for Federal projects undergoing evaluation for significant
impacts to the human environment. This includes participating in
updates to RMPs. As a cooperating agency, we have the opportunity to
provide recommendations to the action agency to avoid impacts or
enhance conservation for least chub and its habitat. For projects where
we are not a cooperating agency, we often review proposed actions and
provide recommendations to minimize and mitigate impacts to fish and
wildlife resources.
Acceptance of our NEPA recommendations is at the discretion of the
action agency. The BLM land management practices are intended to ensure
avoidance of negative effects to species whenever possible, while also
providing for multiple-use mandates; therefore, maintaining or
enhancing least chub habitat is considered in conjunction with other
agency priorities.
As described in Factor A, BLM designated the Gandy Salt Marsh as an
ACEC, and it is closed to oil and gas leasing (Jimenez 2009, pers.
comm.). In addition, the Fillmore Oil and Gas Environmental Assessment
provides lease notices that can protect least chub and their habitats.
We conclude in Factor A that oil and gas recovery on BLM lands near
least chub habitats is anticipated to occur at a slow rate and is not
considered a significant threat now or in the foreseeable future. The
aforementioned lease notices and other potential RMP protection
measures will thus be beneficial for site-specific management; however,
we do not anticipate a significant threat from activities on BLM lands
to the existence of the least chub. Therefore, we find that the current
regulatory structure for oil and gas leasing is adequate to protect
least chub and its habitat from this potential threat.
Least chub population areas contain wetland habitats, and section
404 of the Clean Water Act regulates fill in wetlands that meet certain
jurisdictional requirements. Activities that result in fill of
jurisdictional wetland habitat require a section 404 permit. We can
review permit applications and provide recommendations to avoid and
minimize impacts and implement conservation measures for fish and
wildlife resources, including the least chub. However, incorporation of
Service recommendations into section 404 permits is at the discretion
of the U.S. Army Corps of Engineers. In addition, not all activities in
wetlands involve fill and not all wetlands are ``jurisdictional.''
Regardless, we have evaluated threats to the species' habitat where
fill of wetlands may occur, including peat mining and oil and gas
development. At this time we do not have information to indicate that
this is at a level that threatens the species now or in the foreseeable
future.
Summary of Factor D
We find that regulatory mechanisms related specifically to land
management are sufficient for mitigating potential threats from land
development to the least chub at four of the population sites: Mona
Springs (URMCC land acquisition), Gandy Salt Marsh (BLM ACEC), Bishop
Springs (protection of water rights), and Clear Lake (UDWR WMA). The
UDWR continues to work with landowners at Mills Valley and the Leland
Harris Spring Complex to implement beneficial grazing practices and
maintain fences; however, because livestock-grazing-related impacts are
still observed at most extant least chub sites, we determined that
grazing is considered a significant threat to the least chub (see
Factor A. Livestock Grazing).
The BLM has provided protective mechanisms in the form of lease
notices for conservation agreement and sensitive species, including the
least chub, which can minimize impacts from oil and gas drilling. We
also retain the ability to comment on NEPA evaluations for other
projects on BLM lands that may impact the least chub. We determined
that oil and gas drilling is not a threat to the least chub given the
low level of expected energy development in the area (see Factor A.
Mining, and Oil and Gas Leasing and Development).
Regulatory mechanisms are not in place to sufficiently protect the
least chub from local or large-scale groundwater withdrawal. See Factor
A for more information regarding water rights and proposed groundwater
withdrawal.
Although mosquito spraying is not prevented by regulatory
mechanisms, we have no information indicating that mosquito spraying is
a significant threat to the least chub.
We find that the inadequacy of existing mechanisms to regulate
groundwater withdrawal is a threat now and in the foreseeable future
for the least chub.
E. Other Natural or Manmade Factors Affecting Its Continued Existence.
Natural and manmade threats to the species include: (1)
hybridization; (2) loss of genetic diversity; (3) stochastic
disturbance and population isolation; (4) drought and climate change;
and (5) cumulative effects.
(1) Hybridization
Hybridization can be a concern for some fish populations. An
introgressed population results when a genetically similar species is
introduced into or invades least chub habitat, the two species
interbreed (i.e., hybridize), and the resulting hybrids survive and
reproduce. If the hybrids backcross with one or both of the parental
species, genetic introgression occurs (Schwaner and Sullivan 2009, p.
198). Continual introgression can eventually lead to the loss of
genetic identity of one or both parent species, thus resulting in a
``hybrid swarm'' consisting entirely of individual fish that often
contain variable proportions of genetic material from both of the
parental species (Miller and Behnke 1985, p. 514).
Hybridization is commonly associated with disturbed environments
(Hubbs 1955, p. 18). In complex habitats, reproductive isolator
mechanisms can be eliminated as a result of habitat alteration and
degradation, and resultantly, overlaps of reproductive niches and
breakdowns of behavior occur due to overcrowding (Crawford 1979, p. 74;
Lamarra 1981, p. 7). The Bonneville Basin has suffered major
alterations to its aquatic environments, including loss of habitat
through water diversions (Sigler and Sigler 1987, p. 39). Disturbances
allow dispersal of species to habitats where they did not naturally
occur. Water diversions may allow isolated springs that previously held
distinctly separate populations (allopatric) to overlap habitats
(sympatry) and present an opportunity for hybridization to occur.
Habitats such as playa marshes of the Utah west desert may become
restricted to spring heads as a result of water diversion, drought, and
climate change. Inadequate habitat diversity forces sympatric species
into close spawning proximity. Hybridization is even more likely since
least chub are broadcast spawners for an extended period of time, and
this timeframe can overlap with the spawning period of other species,
including the native Utah chub and
[[Page 35414]]
speckled dace (Crawford 1979, p. 74; Miller and Behnke 1985, p. 509).
A morphometric study of specimens collected in 1977 and 1978
documented hybridization of least chub with Utah chub (Gila atraria)
and speckled dace (Rhinichthys osculus) at five locations (Workman et
al. 1979, pp. 156-158; Miller and Behnke 1985, p. 510). Least chub
populations no longer occur at three of these locations, and the other
two - Gandy Salt Marsh and Bishop Springs (documented as Foote
Reservoir at the time) - are relatively healthy least chub populations
that had no evidence of hybridization in genetic samples collected in
1997. Although no hybridization-specific studies have been conducted on
least chub, recent genetic investigations have not documented
hybridization in extant least chub populations (Mock and Miller 2003,
p. 10).
In summary, most habitats where least chub hybrids were found in
the late 1970s consisted of altered systems that lacked the complexity
required for reproductive isolation. Least chub no longer occur at
three of these sites, and no new evidence of hybridization has surfaced
for the other two extant locations. Despite the recorded incidence of
hybridization in the past, there are no known new occurrences.
Therefore, hybridization is not considered a significant threat to the
least chub now or in the foreseeable future.
(2) Loss of Genetic Diversity
The level of genetic diversity in individual fish populations
influences survival and adaptability to environmental change.
Maintaining sufficient levels of genetic diversity within all least
chub populations is important, primarily because they exist in small,
isolated populations compared to the once-expansive historical
populations of Lake Bonneville. Maintaining genetic diversity in
refugia and source populations is important as well.
The patterns of genetic divergence and diversity within and among
populations were described for five of the six naturally occurring
least chub populations (six including the population now functionally
extirpated at Mona Springs), representing three of the known locations
(Snake Valley and Mona Springs in the Great Salt Lake subbasin, and
Mills Valley in the Sevier subbasin) (Mock and Miller 2005, pp. 273-
275). The analysis included amplified fragment-length polymorphism
analysis and mitochondrial DNA sequencing. Pronounced, but temporally
shallow, genetic structuring among these three locations was apparent
and consistent with patterns of recent and historical hydrogeographic
isolation. The most genetically divergent population in this analysis
was in Mona Springs, at the extreme southeastern reach of the Great
Salt Lake subbasin, followed by the Mills Valley population in the
Sevier subbasin. The three Snake Valley populations (Leland Harris
Spring Complex, Gandy Salt Marsh, and Bishop Springs) were genetically
similar, which is expected due to their spatial proximity. The sixth
and southernmost population at Clear Lake was not included in the
initial analyses (Mock and Miller 2005, pp. 273-275), but later
analysis indicated that the population is most similar to the Mills
Valley population, which is consistent with their location in the
Sevier subbasin. The Clear Lake population was distinct from, and
possibly more diverse than, the Mills Valley population (Mock and
Bjerregaard 2007, p. 146).
Genetic diversity within naturally occurring least chub populations
appears to be healthy with respect to molecular diversity (Mock and
Miller 2005, pp. 273-275). Gandy Salt Marsh and Leland Harris Spring
Complex contain the highest diversity. This suggests that: (1) These
least chub populations are large enough to avoid significant historical
genetic drift as their populations become more isolated from each
other; or (2) these populations have been historically large, and their
recent decline has been so rapid that the loss of population genetic
diversity is not yet detectable. Genetic drift affects the genetic
makeup of the population but, unlike natural selection, through an
entirely random process. So although genetic drift is a mechanism of
evolution, it does not work to produce adaptations. Thus, genetic drift
may rapidly reduce population-level genetic diversity if populations
stay small or are subject to continued bottlenecks (Mock and Miller
2005, p. 276).
Translocated populations in Lucin and Walter Springs maintained the
genetic identity of their source populations (Gandy Salt Marsh and
Leland Harris Spring Complex for Lucin Springs, and Leland Harris
Spring Complex for Walter Springs) and showed no evidence of a genetic
bottleneck (Mock and Miller 2005, pp. 273-275). However, this result is
not unusual because these translocated populations were separated from
their source populations for only a few generations. Bottlenecks in
confined, strong-source, and refugial populations can lead to adaptive
divergence that is not yet detectable with genetic techniques but may
be reflected in behavioral changes and habitat adaptations as a result
of the hatchery environment. These may cause a loss of fitness in
naturally occurring populations if refugia and source individuals are
used in a supplemental capacity (Mock and Miller 2005, pp. 273-275).
In summary, we find that extant wild least chub natural populations
show adequate genetic diversity to sustain healthy populations, and
bottlenecks are not apparent in wild, transplanted, or hatchery
populations. As described in part (3) of this section, refugia exist
for four of the five persisting wild sites, and these can provide
supplementation to the genetic pools of individual populations if
necessary.
(3) Environmentally Stochastic Disturbance and Population Isolation
Environmentally stochastic events can include several types of
natural events, such as drought, wildfire and its resultant effects, or
flood. Least chub populations could be affected by drought, especially
when exacerbated by water withdrawal or, potentially, climate change.
We address climate change in part (4) of this section.
Least chub populations are isolated, both naturally and as the
result of human impacts. Habitat connectivity is absent among the three
east/southeast Bonneville Basin populations, and the west desert
populations are similarly disconnected except in years of exceptionally
high water (Perkins et al. 1998, p. 23). We have no evidence of least
chub populations being affected by fire or its resultant effect such as
siltation; however, one translocated population was eliminated by
flooding of the Great Salt Lake (see Translocation section).
Translocated least chub populations can successfully maintain
genetic diversity of wild populations (Mock and Miller 2005, pp. 273-
277). Refuge or hatchery populations are established for three (Bishop
Spring Complex, Mills Valley, and Clear Lake) of the five extant least
chub populations as well as for the functionally extirpated Mona
Springs population (Hines et al. 2008, pp. 34-50). Until management
measures can be implemented to increase the quantity and quality of new
sites and existing habitats, refuge populations provide a source of
genetic material that stores adaptive differences not detectable with
molecular markers that may vary within populations. These might include
habitat quality parameters, seasonal temperature regimes, life-history
traits, and morphology (Mock and Miller 2003,
[[Page 35415]]
pp. 18-19; Mock and Bjerregaard 2007, p. 146).
In summary, loss of connectivity resulting in small, genetically
isolated populations is a concern and requires ongoing monitoring;
however, genetic stocks from four wild least chub populations are
available from established refugia to augment the gene pools of extant
populations and prevent genetic bottlenecks. Therefore, we have
determined that environmentally stochastic disturbance and population
isolation is not considered a threat to the least chub now or in the
foreseeable future.
(4) Climate Change
The groundwater flow system encompassing least chub habitat is
affected by natural climatic conditions, primarily precipitation and
temperature (Welch et al. 2007, p. 37). Least chub have evolved in the
Great Basin desert ecosystem, demonstrating their ability to withstand
historical climatic variability, including drought conditions (Hines et
al. 2008, pp. 19, 26). However, under future climatic conditions and
the added pressure of human water consumption, these evolutionary
adaptations may not be adequate to guarantee long-term survival of
least chub populations.
Climate variability adds uncertainty to predictions of water
recharge and availability of natural aquifers (Welch et al. 2007, p.
48). Predictions of future climatic conditions can no longer rely on
analysis of past climatic trends, but must instead take into account
predicted global climate change. Therefore, it is important to consider
how future climatic conditions may impact least chub. Both the IPCC and
the U.S. Global Climate Change Program conclude that changes to
climatic conditions, such as temperature and precipitation regimes, are
occurring and are expected to continue in western North America over
the next 100 years (Parson et al. 2000, p. 248; Smith et al. 2000, p.
220; Solomon et al. 2007, p. 70 Table TS.6; Trenberth et al. 2007, pp.
252-253, 262-263). In western North America, surface warming
corresponds with reduced mountain snowpack (Mote et al. 2005 and
Regonda et al. 2005, cited in Vicuna and Dracup 2007, p. 330; Trenberth
et al. 2007, p. 310) and a trend toward earlier snowmelt (Stewart et
al. 2004, pp. 217, 219, 223).
Utah has experienced about 1.6 [deg]C (2.9 [deg]F) of warming over
the last 100 years (1908-2007) (Saunders et al. 2008, p. 44). Modeling
of future climate change for Utah projects the State to warm more than
the average for the entire globe, with fewer frost days, longer growing
seasons, and more heat waves (UBRAC 2007, p. 2). Although exact
temperature increases are not known, projected temperature rise in the
southwestern United States by 2050 ranges between 1.4 and 2.0 [deg]C
(2.5 and 4.5 [deg]F) for a lower emissions scenario, and between 2.5
and 3.1 [deg]C (3.5 and 5.5 [deg]F) for a higher emissions scenario
(USGCRP 2009, p. 129).
Precipitation models predict a reduction in mountain snowpack, a
threat of severe and prolonged episodic drought (UBRAC 2007, p. 3), and
a decline in summer precipitation across all of Utah (p. 18). However,
Utah is in the transition zone for predicted changes in winter
precipitation (between the northwest and southwest United States),
resulting in low confidence in future winter precipitation trends
(UBRAC 2007, p 18).
More locally to least chub, the hydrology of the Great Salt Lake
Basin will be impacted by changes in mountain runoff (UBRAC 2007, p.
18). While predictions indicate that the Great Salt Lake Basin will be
affected by declining mountain snowpack and the resulting runoff, the
timing and extent of these changes are unclear (UBRAC 2007, p. 19).
Drought conditions and higher evaporation rates result in lowered
groundwater levels, reduced spring flows, and reductions in size and
depth of pool habitat for least chub (Wilson 2006, p. 8). Although
current data and climate predictions do not indicate the exact nature
of future changes to extant least chub habitat sites, we can assume
that similar effects will be likely.
Because the least chub depends on small, ephemeral springfed
wetlands for major portions of its life history (spawning, nursery
niches, and feeding) and the amount of this habitat available will
likely be reduced and restricted to spring heads, the severity of
climate change is an important factor in the species' persistence.
Under circumstances of restricted habitats, both hybridization and
extirpation have occurred (Hubbs 1955, p. 18; Miller and Behnke 1985,
p. 514). Additionally, the species is bound by dispersal barriers
throughout its range and cannot retreat to additional habitats or
easily recolonize areas after they have been extirpated.
Despite the clear evidence that climate change has had an effect on
temperature over the last 100 years, as well as its potential causal
association with more intense drought conditions that were experienced
in the southwestern United States over the last decade (see Factor A.
Drought), the information available to us at this time does not suggest
that climate change alone is a significant threat to least chub. While
climate change is likely to have affected aquatic resources to some
extent in the past, including habitat used by least chub, at this time
our analysis indicates that groundwater withdrawal historically caused
a more significant long-term impact and that separating the effects of
climate change from those of groundwater withdrawal is not possible.
Likewise, we determine that groundwater withdrawal will be the
overriding impact to least chub in the foreseeable future.
(5) Cumulative Effects
We cannot completely predict the cumulative effects of climate
change, current and future groundwater withdrawal, and drought on least
chub at this time, but we know that each will occur to some extent and
be compounded by the others. At least five Snake Valley populations,
and as many as 15 springs of occupied least chub sites, have been
extirpated in the last 30 years as a result of drought or irrigation
practices (see previous sections, Historical Occurrences and Current
Distribution). Snake Valley harbors the last remaining native habitats
and the last three naturally occurring least chub populations that are
not severely impacted by nonnative fish and urbanization.
The effects of proposed large-scale groundwater withdrawal as
described in Factor A are likely to compound the effects that localized
groundwater development has had on least chub. As described above, past
water development in localized areas has resulted in drying of least
chub habitat and the extirpation of the species from these habitats.
Extant least chub habitats will likely be impacted by reduced water and
consequently wetted area and wetland habitat reductions will result
from these threats individually, and will be compounded cumulatively
with drought and climate change. The cumulative effect of these three
threats will likely intensify the probable effects described in Factor
A: Water Withdrawal and Diversions, Drought, and Factor E: Climate
Change.
In summary, we find that the potential combinations of drought,
current and future groundwater withdrawal, and climate change are
likely to occur and be significant threats to least chub in the
foreseeable future. Significant effects have already occurred as a
result of drought and water diversions, and least chub populations in
Snake Valley have been extirpated.
[[Page 35416]]
Summary of Factor E
We assessed the potential risks of hybridization, loss of genetic
diversity, and environmentally stochastic disturbance to least chub
populations. Limited hybridization was documented in the late 1970s at
five sites; however, least chub are no longer found at these sites or
recent genetic analysis shows that hybridization is no longer an issue
for extant populations. Levels of genetic diversity are appropriate to
sustain least chub populations, and genetic refuges exist for three of
five extant populations. The available information does not suggest
that environmentally stochastic disturbance threatens extant least chub
populations, and if necessary, refugia populations are available to
augment existing populations. Based on the best scientific and
commercial information available, we conclude that least chub is not,
now or in the foreseeable future, threatened by hybridization, loss of
genetic diversity, or environmentally stochastic disturbance.
Least chub have persisted for thousands of years, and naturally
occurring drought does not significantly threaten the species. Climate
models predict that the State may warm more than average, with more
heat waves, less mountain snowpack, and a decline in summer
precipitation. It also is clear that historic and current water
withdrawal, combined with the effects of drought, have had significant
negative effects on least chub. It is anticipated that these phenomena
will combine to reduce the quality and quantity of least chub habitat,
and that when combined with the effects of climate change, these three
factors will significantly threaten the least chub.
Therefore, we find that the least chub is at risk of extinction now
and in the foreseeable future because of the cumulative effects of
climate change, current and future groundwater withdrawal, and drought.
It is difficult to predict the foreseeable future regarding the
cumulative effects of climate change, groundwater withdrawal, and
drought and their resultant effects to least chub. Drought is a natural
event that could happen at any time and is, therefore, a factor
considered for the foreseeable future. Current estimates for climate
change are most accurate for change in temperature, but not
precipitation; and climatic models are generally accurate to about 2030
for this parameter (Solomon et al. 2007, p. 74). Thus, for cumulative
effects of climate change, groundwater withdrawal, and drought, it is
anticipated that large-scale groundwater pumping will be the overriding
factor now and in the foreseeable future.
Finding
As required by the Act, we considered the five factors in assessing
whether the least chub is threatened or endangered throughout all or a
significant portion of its range. We have carefully examined the best
scientific and commercial information available regarding the past,
present, and future threats faced by the least chub. We reviewed the
petition, information available in our files, other available published
and unpublished information, and we consulted with recognized least
chub experts and other Federal, State, and tribal agencies. 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 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 warrants listing as threatened or endangered as those terms are
defined by the Act.
On the basis of the best scientific and commercial information
available, we find that listing of the least chub as threatened or
endangered is warranted. We will make a determination on the status of
the species as threatened or endangered when we do a proposed listing
determination. However, as explained in more detail below, an immediate
proposal of a regulation implementing this action is precluded by
higher priority listing actions, and progress is being made to add or
remove qualified species from the Lists of Endangered and Threatened
Wildlife and Plants.
Review of least chub historic population trends shows that the
current distribution of the least chub is highly reduced from its
historic range. In the late nineteenth century, least chub were very
common in tributaries to Sevier, Utah, and the Great Salt Lakes and for
the next 50 years, surveys demonstrated that this species was found
across the Bonneville Basin in Utah, including Snake Valley. By the
1940s and 1950s, the numbers of least chub in range and abundance
surveys were definitely decreasing with only 11 extant populations
existing by 1979, and 3 extant wild populations known in 1995. UDWR
surveys in the 1990s and 2000s discovered three new populations on the
eastern extent of the historic range; however, one of these populations
is functionally extirpated. The Service now considers five extant,
wild, viable populations to exist, with only three (all in Snake
Valley) being considered secure from the effects of nonnative fish.
This status review found threats to the least chub related to
Factors A, C, D, and E, as described in the following paragraphs and
summarized in Table 4. We find that the best available information for
Factor A indicates that listing the least chub as threatened or
endangered under the Act is warranted due to the effects of livestock
grazing and water withdrawal and diversions on the species and its
habitat. Although the LCCAS and the UDWR have worked to protect least
chub habitat with grazing enclosures where possible and grazing
management plans in some areas, livestock-grazing-related impacts are
still observed at most least chub sites. There is substantial evidence
showing the negative effect of historical groundwater withdrawal on
least chub. While uncertainty exists on the magnitude of effects to the
least chub from proposed large-scale groundwater pumping, concern
regarding the remaining five extant, wild populations is sufficient to
indicate that the species is at risk of extinction in the foreseeable
future, especially when combined with the threat of drought.
We find that the best available information concerning Factor C
(Predation) indicates that listing the least chub as threatened or
endangered under the Act is warranted due to the continuing threat of
nonnative species, particularly mosquitofish, for which there is no
known means of control. Several significant efforts have been made to
remove mosquitofish from least chub habitats, without success. The wild
least chub population at Mona Springs is functionally extirpated due to
mosquitofish, and nonnative fish are present at two of the five
remaining viable populations.
We find that the best available information concerning Factor D
(Inadequacy of Existing Regulatory Mechanisms) indicates that the least
chub is at risk of extinction in the foreseeable future due to
inadequacy of existing regulations to regulate groundwater withdrawals
and ameliorate their effects on least chub habitat.
We find that the best available information concerning Factor E
(Other Natural or Manmade Factors Affecting Its Continued Existence)
indicates that the least chub is at risk of extinction in the
foreseeable future because of the cumulative effects of drought,
current
[[Page 35417]]
and future groundwater withdrawal, and climate change on the remaining
naturally occurring populations in Snake Valley.
Table 4.--Summary of least chub status and threats by population in the
United States.
------------------------------------------------------------------------
Current & Future
Population Current Status Threats
------------------------------------------------------------------------
Leland Harris Spring Complex Extant Factor A. Livestock
grazing,
groundwater
withdrawal,
drought.
Gandy Salt Marsh Extant ...................
Bishop Springs Complex Extant Factor C. Nonnative
fishes.
Mills Valley Extant Factor D.
Inadequacy of
existing
mechanisms to
regulate
groundwater
withdrawal.
Factor E.
Cumulative effects
of climate change,
groundwater
withdrawal, &
drought.
================================
Mona Springs Extirpated Factor A.
Groundwater
withdrawal,
drought.
Factor C. Nonnative
fishes.
Clear Lake Extant Factor D.
Inadequacy of
existing
mechanisms to
regulate
groundwater
withdrawal.
Factor E.
Cumulative effects
of climate change,
groundwater
withdrawal, &
drought.
------------------------------------------------------------------------
Because our finding on the petition to list is warranted but
precluded, we do not need to specifically determine whether it is
appropriate to perform a ``significant portion of the range'' analysis
for this species. Because of a small and restricted population
distribution, and because of threats described above, the least chub
should be listed as threatened or endangered throughout its entire
range. We will review whether to list the species as threatened or
endangered during the proposed listing rule process.
We have reviewed the available information to determine if the
existing and foreseeable threats render the species at risk of
extinction now such that issuing an emergency regulation temporarily
listing the species as per section 4(b)(7) of the Act is warranted. We
have determined that issuing an emergency regulation temporarily
listing the species is not warranted for this species at this time
because five populations persist, three are currently free from
nonnative species, and all are currently free from large-scale
groundwater pumping. However, if at any time we determine that issuing
an emergency regulation temporarily listing the least chub is
warranted, we will initiate this action at that time.
Preclusion and Expeditious Progress
Preclusion is a function of the listing priority of a species in
relation to the resources that are available and competing demands for
those resources. Thus, in any given fiscal year (FY), multiple factors
dictate whether it will be possible to undertake work on a proposed
listing regulation or whether promulgation of such a proposal is
warranted but precluded by higher-priority listing actions.
The resources available for listing actions are determined through
the annual Congressional appropriations process. The appropriation for
the Listing Program is available to support work involving the
following listing actions: Proposed and final listing rules; 90-day and
12-month findings on petitions to add species to the Lists of
Endangered and Threatened Wildlife and Plants (Lists) or to change the
status of a species from threatened to endangered; annual
determinations on prior ``warranted but precluded'' petition findings
as required under section 4(b)(3)(C)(i) of the Act; critical habitat
petition findings; proposed and final rules designating critical
habitat; and litigation-related, administrative, and program-management
functions (including preparing and allocating budgets, responding to
Congressional and public inquiries, and conducting public outreach
regarding listing and critical habitat).
The work involved in preparing various listing documents can be
extensive and may include, but is not limited to: Gathering and
assessing the best scientific and commercial data available and
conducting analyses used as the basis for our decisions; writing and
publishing documents; and obtaining, reviewing, and evaluating public
comments and peer review comments on proposed rules and incorporating
relevant information into final rules. The number of listing actions
that we can undertake in a given year also is influenced by the
complexity of those listing actions; that is, more complex actions
generally are more costly. For example, during the past several years,
the cost (excluding publication costs) for preparing a 12-month
finding, without a proposed rule, has ranged from approximately $11,000
for one species with a restricted range and involving a relatively
uncomplicated analysis to $305,000 for another species that is wide-
ranging and involving a complex analysis.
We cannot spend more than is appropriated for the Listing Program
without violating the Anti-Deficiency Act (see 31 U.S.C.
1341(a)(1)(A)). In addition, in FY 1998 and for each fiscal year since
then, Congress has placed a statutory cap on funds that may be expended
for the Listing Program, equal to the amount expressly appropriated for
that purpose in that fiscal year. This cap was designed to prevent
funds appropriated for other functions under the Act (for example,
recovery funds for removing species from the Lists), or for other
Service programs, from being used for Listing Program actions (see
House Report 105-163, 105\th\ Congress, 1st Session, July 1, 1997).
Recognizing that designation of critical habitat for species
already listed would consume most of the overall Listing Program
appropriation, Congress also put a critical habitat subcap in place in
FY 2002 and has retained it each subsequent year to ensure that some
funds are available for other work in the Listing Program: ``The
critical habitat designation subcap will ensure that some funding is
available to address other listing activities'' (House Report No. 107 -
103, 107\th\ Congress, 1st
[[Page 35418]]
Session, June 19, 2001). In FY 2002 and each year until FY 2006, the
Service has had to use virtually the entire critical habitat subcap to
address court-mandated designations of critical habitat, and
consequently none of the critical habitat subcap funds have been
available for other listing activities. In FY 2007, we were able to use
some of the critical habitat subcap funds to fund proposed listing
determinations for high-priority candidate species. In FY 2009, while
we were unable to use any of the critical habitat subcap funds to fund
proposed listing determinations, we did use some of this money to fund
the critical habitat portion of some proposed listing determinations so
that the proposed listing determination and proposed critical habitat
designation could be combined into one rule, thereby being more
efficient in our work. In FY 2010, we are using some of the critical
habitat subcap funds to fund actions with statutory deadlines.
Thus, through the listing cap, the critical habitat subcap, and the
amount of funds needed to address court-mandated critical habitat
designations, Congress and the courts have in effect determined the
amount of money available for other listing activities. Therefore, the
funds in the listing cap, other than those needed to address court-
mandated critical habitat for already listed species, set the limits on
our determinations of preclusion and expeditious progress.
Congress also recognized that the availability of resources was the
key element in deciding, when making a 12-month petition finding,
whether we would prepare and issue a listing proposal or instead make a
``warranted but precluded'' finding for a given species. The Conference
Report accompanying Public Law 97-304, which established the current
statutory deadlines and the warranted-but-precluded finding, states (in
a discussion on 90-day petition findings that by its own terms also
covers 12-month findings) that the deadlines were ``not intended to
allow the Secretary to delay commencing the rulemaking process for any
reason other than that the existence of pending or imminent proposals
to list species subject to a greater degree of threat would make
allocation of resources to such a petition [that is, for a lower-
ranking species] unwise.''
In FY 2010, expeditious progress is that amount of work that can be
achieved with $10,471,000, which is the amount of money that Congress
appropriated for the Listing Program (that is, the portion of the
Listing Program funding not related to critical habitat designations
for species that are already listed). However these funds are not
enough to fully fund all our court-ordered and statutory listing
actions in FY 2010, so we are using $1,114,417 of our critical habitat
subcap funds in order to work on all of our required petition findings
and listing determinations. This brings the total amount of funds we
have for listing actions in FY 2010 to $11,585,417. Our process is to
make our determinations of preclusion on a nationwide basis to ensure
that the species most in need of listing will be addressed first and
also because we allocate our listing budget on a nationwide basis. The
$11,585,417 is being used to fund work in the following categories:
compliance with court orders and court-approved settlement agreements
requiring that petition findings or listing determinations be completed
by a specific date; section 4 (of the Act) listing actions with
absolute statutory deadlines; essential litigation-related,
administrative, and listing program-management functions; and high-
priority listing actions for some of our candidate species.
In 2009, the responsibility for listing foreign species under the
Act was transferred from the Division of Scientific Authority,
International Affairs Program, to the Endangered Species Program.
Starting in FY 2010, a portion of our funding is being used to work on
the actions described above as they apply to listing actions for
foreign species. This has the potential to further reduce funding
available for domestic listing actions, although there are currently no
foreign species issues included in our high-priority listing actions at
this time. The allocations for each specific listing action are
identified in the Service's FY 2010 Allocation Table (part of our
administrative record).
In FY 2007, we had more than 120 species with an LPN of 2, based on
our September 21, 1983, guidance for assigning an LPN for each
candidate species (48 FR 43098). Using this guidance, we assign each
candidate an LPN of 1 to 12, depending on the magnitude of threats
(high vs. moderate to low), immediacy of threats (imminent or
nonimminent), and taxonomic status of the species (in order of
priority: monotypic genus (a species that is the sole member of a
genus); species; or part of a species (subspecies, distinct population
segment, or significant portion of the range)). The lower the listing
priority number, the higher the listing priority (that is, a species
with an LPN of 1 would have the highest listing priority). Because of
the large number of high-priority species, we further ranked the
candidate species with an LPN of 2 by using the following extinction-
risk type criteria: International Union for the Conservation of Nature
and Natural Resources (IUCN) Red list status/rank, Heritage rank
(provided by NatureServe), Heritage threat rank (provided by
NatureServe), and species currently with fewer than 50 individuals, or
4 or fewer populations.
Those species with the highest IUCN rank (critically endangered),
the highest Heritage rank (G1), the highest Heritage threat rank
(substantial, imminent threats), and currently with fewer than 50
individuals, or fewer than 4 populations, comprised a group of
approximately 40 candidate species (``Top 40''). These 40 candidate
species have had the highest priority to receive funding to work on a
proposed listing determination. As we work on proposed and final
listing rules for these 40 candidates, we are applying the ranking
criteria to the next group of candidates with an LPN of 2 and 3 to
determine the next set of highest priority candidate species.
To be more efficient in our listing process, as we work on proposed
rules for these species in the next several years, we are preparing
multispecies proposals when appropriate, and these may include species
with lower priority if they overlap geographically or have the same
threats as a species with an LPN of 2. In addition, available staff
resources are also a factor in determining high-priority species
provided with funding. Finally, proposed rules for reclassification of
threatened species to endangered are lower priority, since as listed
species, they are already afforded the protection of the Act and
implementing regulations.
We assign the least chub a Listing Priority Number (LPN) of 7 based
on our finding that the species faces threats that are of moderate
magnitude and high imminence. Under the Service's LPN Guidance
(September 21, 1983; 48 FR 43098), the magnitude of threat is the first
criterion we look at when establishing a listing priority. The guidance
indicates that species with the highest magnitude of threat are those
species facing the greatest threats to their continued existence. These
species receive the highest listing priority. At present, the threats
facing the least chub do not meet the highest magnitude rank, because
the threats are not of uniform intensity and the level of the threats
is moderate. Although many of the factors we analyzed (e.g., grazing,
groundwater withdrawal, nonnative species) are present throughout the
range, they are
[[Page 35419]]
not to the level that they are causing high-magnitude threats to least
chub in the majority of the five remaining populations. Grazing,
groundwater withdrawal, and nonnative predation threats are of high
magnitude in some populations but are of low magnitude or nonexistent
in other populations, such that when considering the overall species'
range, the threats average out to being of moderate magnitude.
Under our LPN Guidance, the second criterion we consider in
assigning a listing priority is the immediacy of threats. This
criterion is intended to ensure that the species facing actual,
identifiable threats are given priority over those for which threats
are only potential or that are intrinsically vulnerable but are not
known to be presently facing such threats. We consider the threats
imminent because we have factual information that the threats are
identifiable and that the species is currently facing them in many
portions of its range. These actual, identifiable threats are covered
in greater detail in factors A and C of this finding and include
livestock grazing, groundwater withdrawal, and nonnative species
predation.
The third criterion in our LPN guidance is intended to devote
resources to those species representing highly distinctive or isolated
gene pools as reflected by taxonomy. The least chub is a species within
a monotypic genus, and therefore it receives a higher priority than a
species, subspecies, or DPS.
We will continue to monitor the threats to the least chub, and the
species' status on an annual basis, and should the magnitude or the
imminence of the threats change, we will revisit our assessment of LPN.
Because we assigned the least chub an LPN of 7, work on a proposed
listing determination for the least chub is precluded by work on higher
priority listing actions with absolute statutory, court ordered, or
court-approved deadlines and final listing determinations for those
species that were proposed for listing with funds from FY 2009. This
work includes all the actions listed in the tables below under
expeditious progress (see tables 5 and 6).
As explained above, a determination that listing is warranted but
precluded must also demonstrate that expeditious progress is being made
to add or remove qualified species to and from the Lists of Endangered
and Threatened Wildlife and Plants. (Although we do not discuss it in
detail here, we are also making expeditious progress in removing
species from the Lists under the Recovery program, which is funded by a
separate line item in the budget of the Endangered Species Program. As
explained above in our description of the statutory cap on Listing
Program funds, the Recovery Program funds and actions supported by them
cannot be considered in determining expeditious progress made in the
Listing Program.) As with our ``precluded'' finding, expeditious
progress in adding qualified species to the Lists is a function of the
resources available and the competing demands for those funds. Given
that limitation, we find that we are making progress in FY 2010 in the
Listing Program. This progress included preparing and publishing the
following determinations:
Table 5.--FY 2010 completed listing actions.
----------------------------------------------------------------------------------------------------------------
Publication Date Title Actions FR Pages
----------------------------------------------------------------------------------------------------------------
10/08/2009 Listing Lepidium Final Listing 74 FR 52013-52064
papilliferum (Slickspot Threatened
Peppergrass) as a
Threatened Species
Throughout Its Range.
=====================================
10/27/2009 90-day Finding on a Notice of 90-day 74 FR 55177-55180
Petition To List the Petition Finding, Not
American Dipper in the substantial
Black Hills of South
Dakota as Threatened or
Endangered
=====================================
10/28/2009 Status Review of Arctic Notice of Intent to 74 FR 55524-55525
Grayling (Thymallus Conduct
arcticus) in the Upper Status Review..........
Missouri River System
=====================================
11/03/2009 Listing the British Proposed Listing 74 FR 56757-56770
Columbia Distinct Threatened
Population Segment of
the Queen Charlotte
Goshawk Under the
Endangered Species Act:
Proposed rule.
=====================================
11/03/2009 Listing the Salmon- Proposed Listing 74 FR 56770-56791
Crested Cockatoo as Threatened
Threatened Throughout
Its Range with Special
Rule
=====================================
11/23/2009 Status Review of Notice of Intent to 74 FR 61100-61102
Gunnison sage-grouse Conduct
(Centrocercus minimus) Status Review..........
=====================================
12/03/2009 12-Month Finding on a Notice of 12-month 74 FR 63343-63366
Petition to List the petition
Black-tailed Prairie finding, Not warranted.
Dog as Threatened or
Endangered
=====================================
12/03/2009 90-Day Finding on a Notice of 90-day 74 FR 63337-63343
Petition to List Petition Finding,
Sprague's Pipit as Substantial
Threatened or
Endangered
=====================================
12/15/2009 90-Day Finding on Notice of 90-day 74 FR 66260-66271
Petitions To List Nine Petition Finding,
Species of Mussels From Substantial
Texas as Threatened or
Endangered With
Critical Habitat
=====================================
12/16/2009 Partial 90-Day Finding Notice of 90-day 74 FR 66865-66905
on a Petition to List Petition Finding, Not
475 Species in the substantial and
Southwestern United Subtantial
States as Threatened or
Endangered With
Critical Habitat
=====================================
12/17/2009 12-month Finding on a Notice of 12-month 74 FR 66937-66950
Petition To Change the petition
Final Listing of the finding, Warranted but
Distinct Population precluded.
Segment of the Canada
Lynx To Include New
Mexico
=====================================
[[Page 35420]]
1/05/2010 Listing Foreign Bird Proposed Listing 75 FR 605-649
Species in Peru and Endangered
Bolivia as Endangered
Throughout Their Range
=====================================
1/05/2010 Listing Six Foreign Proposed Listing 75 FR 286-310
Birds as Endangered Endangered
Throughout Their Range
=====================================
1/05/2010 Withdrawal of Proposed Proposed rule, 75 FR 310-316
Rule to List Cook's withdrawal
Petrel
=====================================
1/05/2010 Final Rule to List the Final Listing 75 FR 235-250
Galapagos Petrel and Threatened
Heinroth's Shearwater
as Threatened
Throughout Their Ranges
=====================================
1/20/2010 Initiation of Status Notice of Intent to 75 FR 3190-3191
Review for Agave Conduct
eggersiana and Solanum Status Review..........
conocarpum
=====================================
2/09/2010 12-month Finding on a Notice of 12-month 75 FR 6437-6471
Petition to List the petition
American Pika as finding, Not warranted.
Threatened or
Endangered
=====================================
2/25/2010 12-Month Finding on a Notice of 12-month 75 FR 8601-8621
Petition To List the petition finding, Not
Sonoran Desert warranted
Population of the Bald
Eagle as a Threatened
or Endangered Distinct
Population Segment
=====================================
2/25/2010 Withdrawal of Proposed Withdrawal of Proposed 75 FR 8621-8644
Rule To List the Rule to List
Southwestern Washington/
Columbia River Distinct
Population Segment of
Coastal Cutthroat Trout
(Oncorhynchus clarki
clarki) as Threatened
=====================================
3/18/2010 90-Day Finding on a Notice of 90-day 75 FR 13068-13071
Petition to List the Petition Finding,
Berry Cave salamander Substantial
as Endangered
=====================================
3/23/2010 90-Day Finding on a Notice of 90-day 75 FR 13717-13720
Petition to List the Petition Finding, Not
Southern Hickorynut substantial
Mussel (Obovaria
jacksoniana) as
Endangered or
Threatened
=====================================
3/23/2010 90-Day Finding on a Notice of 90-day 75 FR 13720-13726
Petition to List the Petition Finding,
Striped Newt as Substantial
Threatened
=====================================
3/23/2010 12-Month Findings for Notice of 12-month 75 FR 13910-14014
Petitions to List the petition finding,
Greater Sage-Grouse Warranted but
(Centrocercus precluded
urophasianus)as
Threatened or
Endangered
=====================================
3/31/2010 12-Month Finding on a Notice of 12-month 75 FR 16050-16065
Petition to List the petition finding,
Tucson Shovel-Nosed Warranted but
Snake (Chionactis precluded
occipitalis klauberi)
as Threatened or
Endangered with
Critical Habitat
=====================================
4/5/2010 90-Day Finding on a Notice of 90-day 75 FR 17062-17070
Petition To List Petition Finding,
Thorne's Hairstreak Substantial
Butterfly as or
Endangered
=====================================
4/6/2010 12-month Finding on a Notice of 12-month 75 FR 17352-17363
Petition To List the petition finding, Not
Mountain Whitefish in warranted
the Big Lost River,
Idaho, as Endangered or
Threatened
=====================================
4/6/2010 90-Day Finding on a Notice of 90-day 75 FR 17363-17367
Petition to List a Petition Finding, Not
Stonefly (Isoperla substantial
jewetti) and a Mayfly
(Fallceon eatoni) as
Threatened or
Endangered with
Critical Habitat
=====================================
4/7/2010 12-Month Finding on a Notice of 12-month 75 FR 17667-17680
Petition to Reclassify petition finding,
the Delta Smelt From Warranted but
Threatened to precluded
Endangered Throughout
Its Range
=====================================
4/13/2010 Determination of Final Listing 75 FR 18959-19165
Endangered Status for Endangered
48 Species on Kauai and
Designation of Critical
Habitat
=====================================
4/15/2010 Initiation of Status Notice of Initiation of 75 FR 19591-19592
Review of the North Status Review
American Wolverine in
the Contiguous United
States
=====================================
4/15/2010 12-Month Finding on a Notice of 12-month 75 FR 19592-19607
Petition to List the petition finding, Not
Wyoming Pocket Gopher warranted
as Endangered or
Threatened with
Critical Habitat
=====================================
4/16/2010 90-Day Finding on a Notice of 90-day 75 FR 19925-19935
Petition to List a Petition Finding,
Distinct Population Substantial
Segment of the Fisher
in Its United States
Northern Rocky Mountain
Range as Endangered or
Threatened with
Critical Habitat
=====================================
4/20/2010 Initiation of Status Notice of Initiation of 75 FR 20547-20548
Review for Sacramento Status Review
splittail (Pogonichthys
macrolepidotus)
=====================================
4/26/2010 90-Day Finding on a Notice of 90-day 75 FR 21568-21571
Petition to List the Petition Finding,
Harlequin Butterfly as Substantial
Endangered
=====================================
[[Page 35421]]
4/27/2010 12-Month Finding on a Notice of 12-month 75 FR 22012-22025
Petition to List petition finding, Not
Susan's Purse-making warranted
Caddisfly (Ochrotrichia
susanae) as Threatened
or Endangered
=====================================
4/27/2010 90-day Finding on a Notice of 90-day 75 FR 22063-22070
Petition to List the Petition Finding,
Mohave Ground Squirrel Substantial
as Endangered with
Critical Habitat
=====================================
5/4/2010 90-Day Finding on a Notice of 90-day 75 FR 23654-23663
Petition to List Hermes Petition Finding,
Copper Butterfly as Substantial
Threatened or
Endangered
----------------------------------------------------------------------------------------------------------------
Our expeditious progress also includes work on listing actions that
we funded in FY 2010 but have not yet been completed to date. These
actions are listed below. Actions in the top section of the table are
being conducted under a deadline set by a court. Actions in the middle
section of the table are being conducted to meet statutory timelines,
that is, timelines required under the Act. Actions in the bottom
section of the table are high-priority listing actions. These actions
include work primarily on species with an LPN of 2, and selection of
these species is partially based on available staff resources, and when
appropriate, include species with a lower priority if they overlap
geographically or have the same threats as the species with the high
priority. Including these species together in the same proposed rule
results in considerable savings in time and funding, as compared to
preparing separate proposed rules for each of them in the future.
Table 6.--Actions funded in FY 2010 but not yet completed.
------------------------------------------------------------------------
Species Action
------------------------------------------------------------------------
Actions Subject to Court Order/Settlement Agreement
------------------------------------------------------------------------
6 Birds from Eurasia Final listing determination
------------------------------------------------------------------------
Flat-tailed horned lizard Final listing determination
------------------------------------------------------------------------
Mountain plover Final listing determination
------------------------------------------------------------------------
6 Birds from Peru Proposed listing
determination
------------------------------------------------------------------------
Sacramento splittail Proposed listing
determination
------------------------------------------------------------------------
White-tailed prairie dog 12-month petition finding
------------------------------------------------------------------------
Gunnison sage-grouse 12-month petition finding
------------------------------------------------------------------------
Wolverine 12-month petition finding
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Arctic grayling 12-month petition finding
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Agave eggergsiana 12-month petition finding
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Solanum conocarpum 12-month petition finding
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Mountain plover 12-month petition finding
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Thorne's Hairstreak Butterfly 12-month petition finding
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Hermes copper butterfly 12-month petition finding
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Actions with Statutory Deadlines
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Casey's june beetle Final listing determination
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Georgia pigtoe, interrupted rocksnail, and Final listing determination
rough hornsnail
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2 Hawaiian damselflies Final listing determination
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African penguin Final listing determination
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3 Foreign bird species (Andean flamingo, Final listing determination
Chilean woodstar, St. Lucia forest
thrush)
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5 Penguin species Final listing determination
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Southern rockhopper penguin - Campbell Final listing determination
Plateau population
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[[Page 35422]]
5 Bird species from Colombia and Ecuador Final listing determination
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7 Bird species from Brazil Final listing determination
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Queen Charlotte goshawk Final listing determination
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Salmon crested cockatoo Proposed listing
determination
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Black-footed albatross 12-month petition finding
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Mount Charleston blue butterfly 12-month petition finding
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Least chub\1\ 12-month petition finding
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Mojave fringe-toed lizard\1\ 12-month petition finding
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Pygmy rabbit (rangewide)\1\ 12-month petition finding
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Kokanee - Lake Sammamish population\1\ 12-month petition finding
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Delta smelt (uplisting) 12-month petition finding
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Cactus ferruginous pygmy-owl\1\ 12-month petition finding
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Northern leopard frog 12-month petition finding
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Tehachapi slender salamander 12-month petition finding
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Coqui Llanero 12-month petition finding
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White-sided jackrabbit 12-month petition finding
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Jemez Mountains salamander 12-month petition finding
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Dusky tree vole 12-month petition finding
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Eagle Lake trout\1\ 12-month petition finding
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29 of 206 species 12-month petition finding
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Desert tortoise - Sonoran population 12-month petition finding
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Gopher tortoise - eastern population 12-month petition finding
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Amargosa toad 12-month petition finding
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Pacific walrus 12-month petition finding
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Wrights marsh thistle 12-month petition finding
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67 of 475 southwest species 12-month petition finding
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9 Southwest mussel species 12-month petition finding
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14 parrots (foreign species) 12-month petition finding
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Berry Cave salamander\1\ 12-month petition finding
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Striped Newt\1\ 12-month petition finding
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Fisher - Northern Rocky Mountain Range\1\ 12-month petition finding
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Mohave Ground Squirrel\1\ 12-month petition finding
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Puerto Rico Harlequin Butterfly 12-month petition finding
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Southeastern pop snowy plover & wintering 90-day petition finding
pop. of piping plover\1\
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Eagle Lake trout\1\ 90-day petition finding
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Ozark chinquapin\1\ 90-day petition finding
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Smooth-billed ani\1\ 90-day petition finding
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[[Page 35423]]
Bay Springs salamander\1\ 90-day petition finding
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32 species of snails and slugs\1\ 90-day petition finding
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Calopogon oklahomensis\1\ 90-day petition finding
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White-bark pine 90-day petition finding
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42 snail species (Nevada & Utah) 90-day petition finding
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HI yellow-faced bees 90-day petition finding
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Red knot roselaari subspecies 90-day petition finding
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Honduran emerald 90-day petition finding
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Peary caribou 90-day petition finding
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Western gull-billed tern 90-day petition finding
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Plain bison 90-day petition finding
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Giant Palouse earthworm 90-day petition finding
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Mexican gray wolf 90-day petition finding
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Spring Mountains checkerspot butterfly 90-day petition finding
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Spring pygmy sunfish 90-day petition finding
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San Francisco manzanita 90-day petition finding
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Bay skipper 90-day petition finding
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Unsilvered fritillary 90-day petition finding
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Texas kangaroo rat 90-day petition finding
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Spot-tailed earless lizard 90-day petition finding
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Eastern small-footed bat 90-day petition finding
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Northern long-eared bat 90-day petition finding
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Prairie chub 90-day petition finding
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10 species of Great Basin butterfly 90-day petition finding
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6 sand dune (scarab) beetles 90-day petition finding
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Gila monster - Utah population 90-day petition finding
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Golden-winged warbler 90-day petition finding
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Sand-verbena moth 90-day petition finding
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Aztec (beautiful) gilia 90-day petition finding
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Arapahoe snowfly 90-day petition finding
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High Priority Listing Actions\3\
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19 Oahu candidate species\3\ (16 plants, 3 Proposed listing
damselflies) (15 with LPN = 2, 3 with LPN
= 3, 1 with LPN =9)
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17 Maui-Nui candidate species\3\ (14 Proposed listing
plants, 3 tree snails) (12 with LPN = 2,
2 with LPN = 3, 3 with LPN = 8)
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Sand dune lizard\3\ (LPN = 2) Proposed listing
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2 Arizona springsnails\3\ (Pyrgulopsis Proposed listing
bernadina (LPN = 2), Pyrgulopsis
trivialis (LPN = 2))
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2 New Mexico springsnails\3\ (Pyrgulopsis Proposed listing
chupaderae (LPN = 2), Pyrgulopsis
thermalis (LPN = 11))
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2 mussels\3\ (rayed bean (LPN = 2), Proposed listing
snuffbox No LPN)
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[[Page 35424]]
2 mussels\3\ (sheepnose (LPN = 2), Proposed listing
spectaclecase (LPN = 4),)
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Ozark hellbender\2\ (LPN = 3) Proposed listing
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Altamaha spinymussel\3\ (LPN = 2) Proposed listing
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5 southeast fish\3\ (rush darter (LPN = Proposed listing
2), chucky madtom (LPN = 2), yellowcheek
darter (LPN = 2), Cumberland darter (LPN
= 5), laurel dace (LPN = 5))
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8 southeast mussels (southern kidneyshell Proposed listing
(LPN = 2), round ebonyshell (LPN = 2),
Alabama pearlshell (LPN = 2), southern
sandshell (LPN = 5), fuzzy pigtoe (LPN =
5), Choctaw bean (LPN = 5), narrow pigtoe
(LPN = 5), and tapered pigtoe (LPN = 11))
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3 Colorado plants\3\ (Pagosa skyrocket Proposed listing
(Ipomopsis polyantha) (LPN = 2), Parchute
beardtongue (Penstemon debilis) (LPN =
2), Debeque phacelia (Phacelia submutica)
(LPN = 8))
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\1\ Funds for listing actions for these species were provided in
previous FYs.
\2\ We funded a proposed rule for this subspecies with an LPN of 3 ahead
of other species with LPN of 2, because the threats to the species
were so imminent and of a high magnitude that we considered emergency
listing if we were unable to fund work on a proposed listing rule in
FY 2008.
\3\ Funds for these high-priority listing actions were provided in FY
2008 or 2009.
We have endeavored to make our listing actions as efficient and
timely as possible, given the requirements of the relevant law and
regulations, and constraints relating to workload and personnel. We are
continually considering ways to streamline processes or achieve
economies of scale, such as by batching related actions together. Given
our limited budget for implementing section 4 of the Act, these actions
described above collectively constitute expeditious progress.
The least chub will be added to the list of candidate species upon
publication of this 12-month finding. We will continue to monitor the
status of this species as new information becomes available. This
review will determine if a change in status is warranted, including the
need to make prompt use of emergency listing procedures.
We intend that any proposed listing action for the least chub will
be as accurate as possible. Therefore, we will continue to accept
additional information and comments from all concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning this finding.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Utah Field Office
(see ADDRESSES section).
Authors
The primary authors of this notice are the staff members of the
Utah Field Office.
Authority
The authority for this action is section 4 of the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: June 4, 2010
Jeffrey L. Underwood
Acting Director, U.S. Fish and Wildlife Service
[FR Doc. 2010-15070 Filed 6-21-10; 8:45 am]
BILLING CODE 4310-55-S