Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List the Least Chub as Threatened or Endangered, 35398-35424 [2010-15070]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 75, Number 119 (Tuesday, June 22, 2010)]
[Proposed Rules]
[Pages 35398-35424]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-15070]



[[Page 35398]]

-----------------------------------------------------------------------

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 https://www.regulations.gov at Docket Number FWS-R6-ES-2008-0088 and https://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