Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Least Chub (Iotichthys phlegethontis, 61007-61015 [E8-24467]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 73, Number 200 (Wednesday, October 15, 2008)]
[Proposed Rules]
[Pages 61007-61015]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-24467]



[[Page 61007]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R6-ES-2008-0088; MO 9921050083-B2]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Least Chub (Iotichthys phlegethontis) as 
Threatened or Endangered With Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the least chub (Iotichthys 
phlegethontis) as threatened or endangered under the Endangered Species 
Act of 1973, as amended (Act). We find that the petition presents 
substantial scientific or commercial information indicating that 
listing of the least chub may be warranted. Therefore, with the 
publication of this notice, we are initiating a status review of the 
species, and we will issue a 12-month finding to determine if the 
petitioned action is warranted. To ensure that the status review is 
comprehensive, we are soliciting scientific and commercial data 
regarding this species. We will make a determination on critical 
habitat for this species if, and when, we initiate a listing action.

DATES: To allow us adequate time to conduct this review, we request 
that we receive information on or before December 15, 2008.

ADDRESSES: You may submit information by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the instructions for submitting comments.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R6-ES-2008-0088; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
We will not accept e-mail or faxes. We will post all information at 
https://www.regulations.gov. This generally means that we will post any 
personal information you provide us (see the Information Solicited 
section below for more details).

FOR FURTHER INFORMATION CONTACT: Larry Crist, Field Supervisor, Utah 
Ecological Services Field Office, 2369 West Orton Circle, Suite 50, 
West Valley City, UT 84119; telephone 801-975-3330, extension 126. If 
you use a telecommunications device for the deaf (TDD), call the 
Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Information Solicited

    When we make a finding that a petition presents substantial 
information to indicate that listing a species may be warranted, we are 
required to promptly commence a review of the status of the species. To 
ensure that the status review is complete and based on the best 
available scientific and commercial information, we are soliciting 
information from the public, other concerned governmental agencies, 
Native American Tribes, the scientific community, industry, or any 
other interested parties concerning the status of the least chub. We 
are seeking information regarding the species' historical and current 
status and distribution, its biology and ecology, ongoing conservation 
measures for the species and its habitat, and threats to the species 
and its habitat.
    If we determine that listing the least chub is warranted, it is our 
intent to propose critical habitat to the maximum extent prudent and 
determinable at the time we propose to list the species. Therefore, 
with regard to areas within the geographical range currently occupied 
by the least chub, we also request data and information on what may 
constitute physical or biological features essential to the 
conservation of the species, where these features are currently found, 
and whether any of these features may require special management 
considerations or protection. In addition, we request data and 
information regarding whether there are areas outside the geographical 
area occupied by the species that are essential to the conservation of 
the species. Please provide specific information as to what, if any, 
critical habitat you think we should propose for designation if the 
species is proposed for listing, and why such habitat meets the 
requirements of the Act (16 U.S.C. 1531 et seq.).
    Please note that submissions merely stating support or opposition 
to the action under consideration without providing supporting 
information, although noted, will not be considered in making a 
determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is a threatened or endangered 
species shall be made ``solely on the basis of the best scientific and 
commercial data available.'' At the conclusion of the status review, we 
will issue the 12-month finding on the petition, as provided in section 
4(b)(3)(B) of the Act (16 U.S.C. 1533(b)(3)(B)).
    You may submit your information concerning this 90-day finding by 
one of the methods listed in the ADDRESSES section. We will not accept 
comments sent by e-mail or fax or to an address not listed in the 
ADDRESSES section. Finally, we may not consider comments that we do not 
receive by the date specified in the DATES section.
    If you submit information via https://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on https://www.regulations.gov.
    Information and materials we receive, as well as supporting 
documentation we used in preparing this 90-day finding, will be 
available for public inspection on https://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Utah Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Background

    Section 4(b)(3)(A) of the Endangered Species Act requires that we 
make a finding on whether a petition to list, delist, or reclassify a 
species presents substantial scientific or commercial information 
indicating that the petitioned action may be warranted. We are to base 
this finding on information provided in the petition and supporting 
information otherwise available in our files at the time of the 
petition review. To the maximum extent practicable, we are to make this 
finding within 90 days of our receipt of the petition, and publish our 
notice of this finding promptly in the Federal Register.
    Our standard for substantial information as defined in the Code of 
Federal Regulations (CFR) regarding a 90-day petition finding is ``that 
amount of information that would lead a reasonable person to believe 
that the measure proposed in the petition may be warranted'' (50 CFR 
424.14(b)). If we find that the petition presented substantial 
information, we are required to promptly commence a review of the 
status of the species.

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    We received a petition from the Center for Biological Diversity, 
Confederated Tribes of the Goshute Reservation, Great Basin Chapter of 
Trout Unlimited, and Utah Chapter of the Sierra Club, dated June 19, 
2007, requesting that we list the least chub (Iotichthys phlegethontis) 
as threatened or endangered under the Act. Additionally, the petition 
requested that critical habitat be designated concurrent with listing. 
The petition clearly identified itself as a petition and included the 
identification information, as required in 50 CFR 424.14(a). We 
acknowledged receipt of the petition in a letter dated July 13, 2007. 
In that letter we advised the petitioners that we could not address 
their petition at that time because existing court orders and 
settlement agreements for other listing actions required nearly all of 
our listing funding. We also concluded that emergency listing of the 
least chub was not warranted.
    In making this finding, we relied on information provided by the 
petitioners that we determined to be reliable after reviewing sources 
referenced in the petition and available in our files. We evaluated 
that information in accordance with 50 CFR 424.14(b). Our process for 
making this 90-day finding under section 4(b)(3)(A) of the Act is 
limited to a determination of whether the information in the petition 
meets the ``substantial information'' threshold.

Previous Federal Actions

    In 1972, and again in 1989, the least chub was recognized as a 
threatened species by the Endangered Species Committee of the American 
Fisheries Society (Miller 1972, p. 250; Williams et al. 1989, pp. 2, 
5). In 1980, the Service reviewed the species' status and determined 
that there was insufficient data to warrant its listing as an 
endangered or threatened species. On December 30, 1982, the Service 
classified the least chub as a Category 2 Candidate Species (47 FR 
58454). In 1989, we again conducted a status review, and we 
reclassified least chub as a Category 1 Candidate Species (54 FR 554). 
On September 29, 1995, the Service 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 Department of Natural 
Resources (UDNR), Bureau of Land Management (BLM), Bureau of 
Reclamation (BOR), Utah Reclamation and Mitigation Conservation 
Commission (URMCC), Confederated Tribes of the Goshute Reservation, and 
Central Utah Water Conservancy District developed a Least Chub 
Conservation Agreement and Strategy (LCCAS), and formed the Least Chub 
Conservation Team (Perkins et al. 1998). The LCCAS was revised in 2005 
(Bailey et al. 2005). The goal of the agreement is to ensure the 
species' long-term survival within its historic range and assist in the 
development of rangewide conservation efforts. The objectives of the 
agreement 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 Least Chub Conservation Team implements the LCCAS, and monitors 
populations, threats, and habitat conditions.
    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 being addressed and implemented. 
Consequently, the Service withdrew the listing proposal on July 29, 
1999 (64 FR 41061).

Species Information

    The least chub (Iotichthys phlegethontis) is a monotypic cyprinid 
(member of the minnow family) that is typically less than 6.5 
centimeters (2.6 inches) long. The species has broad tolerances to 
habitat conditions that have allowed it to persist in the fluctuating 
environments of the springs and marshes of Utah's West Desert (Lamarra 
1981, p. 1). Least chub are intermittent spawners, releasing a few eggs 
at a time over an extended period from February to September (Crawford 
1979, p. 74). They are opportunistic feeders and use available food 
items, including algae, diatomaceous material, midges, copepods, and 
ostracods (Sigler and Sigler 1987, p. 182; Hickman 1989, p. 8), 
depending on seasons and habitats (Crist and Holden 1980, p. 808; 
Lamarra 1981, p. 5).
    The species is endemic to the Bonneville Basin of Utah where it was 
once widely distributed throughout a variety of habitats, including 
rivers, streams, springs, ponds, marshes, and swamps (Sigler and Miller 
1963, p. 91). Over the past 15,000 years, least chub have persisted in 
relic wetland pockets left by Bonneville and Provo Lakes, which have 
been receding since the Pleistocene period. A decline in the abundance 
of least chub was first noted in the 1940s and 1950s (Osmundson 1985, 
p. 1).
    Currently, six known, wild, extant populations of least chub 
remain. Three are in Snake Valley in Utah's West Desert, and include 
the Leland Harris Spring complex, Gandy Salt Marsh, and Bishop Spring:
    (1) Leland Harris--R.R. Miller collected the first least chub from 
the Leland Harris Spring complex in 1970 (Sigler and Sigler 1987, p. 
182). The site is north of the Juab/Millard County line and is 
primarily on BLM land, but portions are privately owned. The site 
consists of 12 springheads that feed a playa wetland. The habitat 
fluctuates in size seasonally. Least chub is the dominant fish species; 
they are abundant and the population appears to be stable (Hines et al. 
2008, p. 42). The site has been monitored annually by the Utah Division 
of Wildlife Resources (UDWR) since 1993 (Hines et al. 2008, p. 43). 
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. Hubbs 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 is managed by BLM. It consists of 52 
small springheads that drain into a large playa wetland. Least chub 
numbers fluctuate at this site, but they are persistent and nonnative 
species are not present (Hines et al. 2008, p. 40).
    (3) Bishop Springs (Twin Springs)--This spring complex is the 
largest occupied least chub site in Snake Valley. The marsh has four 
large springs containing least chub, including Foote Reservoir, Central 
Spring, and two sites at Twin Springs. These flow into marshlands, 
seeps, and braided channels. The least chub population has remained 
stable; however, nonnatives are present and include common carp 
(Cyprinus carpio), bull frogs (Rana catesbeiana), and a small number of 
bass (Micropterus sp.) (Hines et al. 2008, p. 37).
    The remaining three wild populations are located along the Wasatch 
Front and include Mills Valley and Clear Lake in the Sevier River 
drainage and Mona Springs in the Utah Lake drainage:
    (4) Mills Valley--The Mills Valley population was discovered in 
1996 by UDWR biologists. The site is in the Sevier River drainage in 
Mills Valley, southeast Juab County. It consists of a wetland with many 
springheads throughout the complex. Most of Mills Valley is privately 
owned, but a portion is on the UDWR Mills Meadows Wildlife Management 
Area (WMA). Nonnatives at this site include fathead minnows (Pimephales 
promelas),

[[Page 61009]]

sunfish (Lepomis sp.), and common carp (Cyprinus carpio). Surveys from 
1999 to 2006 indicate a stable least chub population; however, fathead 
minnow numbers during this period have doubled (Hines et al. 2008, p. 
44).
    (5) Clear Lake--In 2003, UDWR biologists found least chub at the 
Clear Lake Waterfowl Management Area. This reserve consists of a 
shallow reservoir and diked ponds. It is managed by UDWR to provide 
waterfowl habitat and is located on the southern edge of the Bonneville 
Basin in Millard County. Nonnatives captured at Clear Lake include 
rainbow trout (Oncorhynchus mykiss) and common carp. Population 
estimates are difficult to determine at the Clear Lake site; however, 
since the discovery of this population, successful recruitment has been 
documented (Hines et al. 2008, p. 45).
    (6) Mona Springs--The Mona Springs population was discovered in 
1995 by biologists from UDWR. The UDWR and BOR acquired 41.5 hectares 
(ha) (102.6 acres (ac)) on the Mona Springs complex (URMCC 2008). Least 
chub at this site may be extirpated as a result of mosquitofish 
(Gambusia affinis) infestation (Hines et al. 2008, p. 34).
    Portions of wild least chub populations have been introduced into 
captive or natural refuge environments by UDWR, including five genetic 
refuge and translocation sites:
    (1) Lucin Pond--Lucin Pond was built to provide cooling water for 
locomotive steam engines for the transcontinental railroad. The water 
is collected from springs in the Pilot Mountains and delivered by an 
antiquated aqueduct a distance of approximately 8 kilometers (km) (5 
miles (mi)). Forty-two least chub were transplanted to Lucin Pond in 
1989 by UDWR biologists; however the origin of these fish was not 
documented. Genetic analysis indicates the fish originated from both 
the Gandy Salt Marsh and Leland Harris populations in Snake Valley 
(Mock and Miller 2005, p. 276). Mosquitofish are abundant in the pond.
    (2) Antelope Island--Garden Creek is a 0.04-ha (0.1-ac) pond that 
was dredged by the Utah Department of Parks and Recreation (UDPR), and 
is fed by a perennial stream. In 2004, 947 least chub were introduced 
to the pond. This site is considered a genetic refuge for the Mona 
Springs population. Reproduction and recruitment are occurring, and 
this transplant area appears to be a success (Hines et al. 2008, p. 
46).
    (3) Atherly Reservoir--Atherly Reservoir is a waterfowl management 
area located in Rush Valley in Tooele County, and operated by UDWR. 
Approximately 13,000 least chub from the Mills Valley population were 
introduced in 2006. Common carp are present at the site. The status of 
the population will be determined after monitoring is conducted (Hines 
et al. 2008, p. 50).
    (4) Fish Springs National Wildlife Refuge--Attempts in 1995 and 
1996 to introduce least chub into spring heads on the refuge were 
unsuccessful due to the reinvasion of mosquitofish. In 2007, least chub 
were introduced into Ibis and Pintail Ponds, two units on the Refuge 
that had been drained and allowed to stay dry over the winter. 
Mosquitofish are present, but the sites are large, the habitat is 
diverse and expansive, and the ponds can be drained periodically (Hines 
et al. 2008, p. 50).
    (5) Red Knolls Pond--This site is located in west Box Elder County. 
Nonnative eradication has been conducted, and the pond is fenced to 
exclude livestock. In 2005, 250 least chub from Bishop Springs were 
introduced. Successful recruitment was observed in 2006 (Hines et al. 
2008, p. 50).
    Least chub are being held and produced at the Wahweap State Fish 
Hatchery in Big Water, Utah, and the Fisheries Experiment Station in 
Logan, Utah. Fish from these stations are used for transplants to 
reintroduction sites.

Threats Analysis

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR 424) set forth the procedures for adding species to 
the Federal Lists of Endangered and Threatened Wildlife and Plants. A 
species may be determined to be an endangered or threatened species due 
to one or more of the five factors described in section 4(a)(1) of the 
Act: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) inadequacy of existing regulatory mechanisms; 
or (E) other natural or manmade factors affecting its continued 
existence. Listing actions may be warranted based on any of the above 
threat factors, singly or in combination.
    In making this 90-day finding, we evaluated whether information 
regarding the least chub, as presented in the petition and other 
information available in our files at the time of petition review, is 
substantial, thereby indicating that listing the least chub as 
threatened or endangered may be warranted. Our evaluation is presented 
below.

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Habitat or Range

    The petitioners state that threats to the species' habitat include: 
(1) Livestock grazing; (2) mining, including peat mining and oil and 
gas leasing and exploration; (3) urban development; and (4) water 
withdrawal and diversion.

Livestock Grazing

    The petitioners state that nearly 100 percent of the wild, extant 
least chub sites have been impacted by livestock in the last 10 years, 
and that direct and indirect impacts from livestock grazing to least 
chub, and aquatic habits in general, is well documented in the 
literature (Schultz and Leininger 1990, pp. 297-299; Fleischner 1994, 
pp. 635-636).
    The petitioners report that livestock grazing impacts at the Mills 
Valley population site are the most serious in existing wild chub 
habitat. Ungulate damage occurs at other least chub sites, including 
Mona Springs, Leland Harris, and Twin Springs south of the Bishop 
Springs site, and Central Spring and Foote Reservoir at the Bishop 
Springs site. They state that most least chub habitats are not 
protected from grazing.
    The petitioners provide general information regarding livestock 
damage to least chub habitats, but do not present specific information 
that livestock damage has resulted in least chub population declines or 
loss of habitat. The LCCAS has identified livestock grazing as a 
potential threat to least chub habitats; the Least Chub Conservation 
Team monitors grazing conditions at least chub population sites, and 
implements protective measures as necessary. At the Mona Springs site, 
an electric fence has been installed around the spring and riparian 
area to exclude cattle. Fencing has also been installed at Gandy Salt 
Marsh, Leland Harris, and Miller Spring to exclude cattle from spring 
head areas. A rotational grazing plan was implemented on 75 ha (188 ac) 
of the Leland Harris site to improve habitat conditions (Hines et al. 
2008, p. 8).
    On the basis of our evaluation of the information presented in the 
petition, we determined that the petition does not present substantial 
information indicating that listing the least chub may be warranted due 
to the present or threatened destruction, modification, or curtailment 
of its habitat or range due to livestock grazing. The Least Chub 
Conservation Team implements monitoring and mitigation measures through 
the LCCAS to reduce the threat

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of livestock grazing to known populations of least chub.

Mining, Oil and Gas Leasing and Exploration

    The petitioners state that mining can negatively impact least chub 
populations by polluting streams or reducing stream flows. The petition 
documents illegal peat mining in Mills Valley on private property in 
the late 1990s. Mills Valley contains one of the larger least chub 
populations. Although the illegal activities have ceased, permits have 
now been issued that could allow future peat mining. The petitioners 
acknowledge that peat mining has not yet occurred, and they reference 
an evaluation indicating that peat mining in Mills Valley might not be 
profitable.
    The petitioners accurately report that oil and gas leasing and 
exploration is ongoing in areas occupied by least chub. They state that 
oil and gas exploration or development can result in impacts to 
springs, marshes, and riparian and other associated vegetation. Water 
used for these operations can impact habitats by polluting streams or 
reducing stream flows.
    The petition documents that, in 2006, BLM leased multiple parcels 
north and west of Miller Spring and in parts of the Leland Harris 
population site. Most of the Gandy Salt Marsh area and portions of 
Mills Valley also have been leased. Applications for permits to drill 
at these sites have not yet been pursued. The petitioners document that 
BLM has attached directional drilling stipulations to the Gandy Salt 
Marsh leases with the intent to minimize impacts to occupied least chub 
habitats.
    Seismic lines have been tested to determine locations of oil and 
gas deposits in the Mills Valley area. Although lease holders have 
committed to avoiding spring and marsh habitats within seismic routes, 
the petitioners believe that impacts will occur from seismic 
exploration. The petitioners state that vehicles, including drilling 
rigs and recording trucks, will crush vegetation and compact soils. 
Routes used for seismic exploration will likely become established 
roads. Surface activities may impact water quality. Drilling activities 
have the potential to release drilling fluids into the aquifer or 
fracture underground geologic features that are associated with spring 
discharge.
    We are aware of past illegal peat mining activities in Mills 
Valley. We reviewed the potential for lawful peat mining to occur in 
the future. As the petitioners cite, UDNR contracted an analysis of the 
quality of the peat in 2003. The report revealed that the peat is of 
inferior quality and would not be financially profitable to harvest. 
Therefore, given our current understanding of peat quality in the area, 
we believe the threat from large-scale peat mining is minimal.
    Oil and gas leasing and exploration have the potential to impact 
least chub habitats. The petition provides general information 
regarding the extent of oil and gas leasing and potential development 
in least chub habitats. However, it does not present specific 
information that this development has resulted in losses, or threatens 
to result in losses, of least chub habitat. The petition correctly 
identifies conservation measures that BLM has attached to leases in 
occupied least chub habitats.
    Much of the information in the petition concerning oil and gas 
leasing and exploration identifies potential rather than actual 
impacts. On the basis of our evaluation of the information presented in 
the petition, we determined that it does not present substantial 
information to indicate that listing the least chub may be warranted 
due to the present or threatened destruction, modification, or 
curtailment of its habitat or range due to mining or oil and gas 
leasing or exploration.
Urban and Suburban Development
    The petitioners indicate that urban and suburban development affect 
least chub habitats with numerous, diverse, direct and indirect 
impacts, including but not limited to: (1) Encroachment that changes 
the hydrology, sediment regimes, and pollution input; (2) human 
occupation near streams and springs that increases the potential for 
introduction of nonnative plants and animals; and (3) alterations of 
stream banks, floodplains, and wetland habitats by increased diversions 
of surface flows and connected groundwater.
    The petitioners state that throughout the Utah Lake hydrological 
subunit, residential development and agricultural and municipal water 
development projects have impacted least chub by converting habitats 
into residential areas and altering natural flows. They indicate that 
the Mona Springs habitat is experiencing rapid growth and that a 
development is expanding to within 2 km (1.25 mi) of the least chub 
site.
    We acknowledge that development has impacted the Wasatch Front 
least chub populations. The least chub was originally reported to be 
common throughout the Bonneville Basin in a variety of habitat types 
(Sigler and Miller 1963, p. 82). Innumerable springs, streams, and 
wetlands along the Wasatch Front have been impacted or eliminated as a 
result of development.
    However, within the currently occupied range of the least chub, no 
wild populations are known to be at risk from urban development. UDWR 
owns the majority of suitable habitat of populations near the Wasatch 
Front, including the Mona Springs and Clear Lake sites, and a portion 
of Mills Valley. In addition, Mills Valley is largely a peat wetland 
with low development potential. On the basis of our evaluation of the 
information presented in the petition, we determined that it does not 
present substantial information to indicate that listing the least chub 
may be warranted due to the present or threatened destruction, 
modification, or curtailment of its habitat or range due to urban or 
suburban development.
Water Withdrawal and Diversion
    The petitioners consider the most significant threat to Snake 
Valley least chub populations to be proposed groundwater withdrawals 
from the Snake Valley aquifer. They indicate that the agency charged 
with supplying water to Las Vegas, the Southern Nevada Water Authority 
(SNWA), has proposed drilling nine groundwater pumping stations just 
inside Nevada on the Utah/Nevada border in Snake Valley, and 
withdrawing up to 3,048 to 3,658 hectare-meters (ha-m) (25,000 to 
30,000 ac-ft) a year of groundwater (Schaeffer and Harrill 1995, p. 
11). The petitioners believe the wells will likely be drilled at 
locations where water from creeks coming off the Snake Range becomes 
subterranean and enters Utah's portion of Snake Valley. If all permits 
are granted, SNWA intends to start pumping in 2015. The petitioners 
state that although SNWA's formal proposal calls for pumping about 
3,048 ha-m (25,000 ac-ft) of water per year from Snake Valley, SNWA has 
applications on file with the Nevada State Engineer for pumping roughly 
double that amount--up to 6,177 ha-m (50,665 ac-ft) per year. In their 
Clark, Lincoln, and White Pine Counties Groundwater Development (GWD) 
Project Final Scoping Package for an Environmental Impact Statement, 
SNWA identified 9 points of diversion in Snake Valley and estimates of 
15 to 25 groundwater production wells (BLM 2006, pp. 1, 2, 17, 18).
    The petitioners reference several studies predicting impacts to the 
dynamics and overall budget of the Snake Valley groundwater system 
(Schaeffer and Harrill 1995, pp. 19-27; Kirby and Hurlow 2005, pp. 21-
26, 30-

[[Page 61011]]

34). They state that once groundwater pumping at the base of the Snake 
Range begins, spring discharge throughout Snake Valley will decrease by 
an unpredictable amount and rate.
    The petitioners present their concerns relative to characterization 
of the aquifer and conclude that groundwater pumping in Spring Valley, 
Nevada, will affect Utah resources. Reductions in the water table of 
the Spring Valley aquifer could decrease the current flow of an 
estimated 488 to 610 ha-m (4,000 to 5,000 ac-ft) per year through the 
alluvial aquifer that delivers groundwater to Snake Valley. The 
petitioners question whether the water in this aquifer is a renewable 
resource. They believe that geologic changes may have occurred since 
the aquifers filled, resulting in partitioning of the aquifers and 
alteration of flows within the system.
    To evaluate the reliability of the petitioners' statements 
concerning water withdrawals, we reviewed the information available to 
us in our files. Aspects of the GWD project have changed since the 
petitioners' description, and will likely continue to change as the 
project progresses. An overview of the GWD project indicates that the 
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. The project would include conveyance of up to 24,384 ha-m 
(200,000 ac-ft) of groundwater--20,360 ha-m (167,000 ac-ft) by SNWA and 
the remaining capacity provided for Lincoln County Water District from 
six hydrographic basins (SNWA 2007, p. 1-1). The groundwater that SNWA 
intends to convey would be from both existing and future permitted 
water rights in hydrographic basins of the Great Salt Lake Desert 
Regional Flow System (Nevada and Utah) and White River Flow System 
(Nevada).
    The GWD project includes construction and operation of groundwater 
production wells, water conveyance facilities, and power facilities. 
The proposed production wells and facilities would be located on public 
lands managed by BLM in Nevada. No facilities are planned in Utah. Two 
portions of the GWD project, the Spring Valley Basin and the Snake 
Valley Basin, may affect Utah resources (SNWA 2007, p. 1-1).
    The Nevada State Engineer issued a ruling on April 16, 2007, 
approving a major portion of the SNWA groundwater rights applications 
for the Spring Valley Hydrographic Basin. SNWA can pump 4,877 ha-m 
(40,000 ac-ft) annually from the Basin, with the potential for an 
additional 2,438 ha-m (20,000 ac-ft) per year based on results of 10 
years of monitoring (State of Nevada 2007, p. 56). The Service and 
other Department of the Interior (DOI) agencies (BLM, National Park 
Service, and Bureau of Indian Affairs) protested SNWA's Spring Valley 
water rights applications when they were filed in 1989, based in part 
on potential impacts to water-dependent resources.
    The DOI agencies reached a stipulated agreement with SNWA for the 
Spring Valley withdrawal, and withdrew their protests before the Nevada 
State Engineer held a hearing. The Stipulated Agreement, signed in 
September 2006, established a process for developing and implementing 
hydrologic and biologic monitoring, management, and mitigation (State 
of Nevada 2007, p. 56). Representatives from the Service and UDWR are 
participating on the Biological Work Group formed under the Spring 
Valley Stipulation Agreement. This group is designing and implementing 
a monitoring, management, and mitigation plan to avoid unreasonable 
adverse effects to water-dependent ecosystems and to maintain or 
enhance baseline biologic integrity and ecological health (SNWA 2006, 
Exhibit 2). In accordance with the Nevada State Engineer's ruling, 5 
years of baseline data must be collected and analyzed prior to 
initiation of any groundwater pumping.
    The Nevada State Engineer hearings on SNWA water rights 
applications in Snake Valley have not yet been scheduled. According to 
the Lincoln County Recreation and Development Act (LCCRDA) of 2004, 
before any trans-basin diversion from groundwater basins located within 
Nevada and Utah, the States must reach an agreement on the division of 
water resources and groundwater flow systems. Negotiations are 
occurring, but Nevada and Utah have not reached agreement. The 
timeframe for an interstate water withdrawal agreement for Snake Valley 
is uncertain.
    The petitioners reference predictions of impacts to the Snake 
Valley aquifer from groundwater pumping (Kirby and Hurlow 2005, p. 33). 
We concur that some or all of these impacts may occur. However, a lack 
of information on the extent of aquifers, their hydraulic properties, 
and the distribution of water levels in the aquifers makes it difficult 
to develop a reliable prediction of the amount or location of draw-
down, or the rate of change in natural discharge, caused by pumping 
(Prudic 2006, p. 3). A hydrologic groundwater flow model specific to 
the six basins being analyzed in the current Environmental Impact 
Statement (EIS), and outlined in the GWD project, is being developed.
    The LCCRDA of 2004 directed 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 in Utah. 
This Basin and Range Carbonate Aquifer System (BARCAS) study was 
conducted by U.S. Geological Survey (USGS), the Desert Research 
Institute, and the State of Utah. USGS released a final report of the 
BARCAS study on February 22, 2008 (USGS 2008).
    The BARCAS study included a water-resources assessment of the 
geologic framework and hydrologic processes influencing the quantity 
and quality of groundwater resources. 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. 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 away (USGS 2008, pp. 2-8).
    The BARCAS study is used to guide designation of basin and regional 
groundwater ``budgets'' for 13 hydrographic areas and the entire study 
area in White Pine County, Nevada. The study included assessment of the 
hydrogeology, recharge and discharge, and groundwater flow and 
geochemistry of the aquifer system. One result from the BARCAS study 
was documentation that the study-wide average annual groundwater 
recharge exceeded annual discharge by about 10,973 ha-m (90,000 ac-ft); 
most of this groundwater surplus exits the study area through Snake 
Valley to the northeast or White River Valley to the south (USGS 2008, 
p. 3).
    In 2007, the Utah State Legislature charged the Utah Geological 
Survey with establishing a groundwater monitoring network in Utah's 
West Desert in response to the proposed groundwater pumping project. 
The objectives of the monitoring network are to define background water 
level and geochemical conditions prior to SNWA pumping, and to quantify 
any changes in these conditions after pumping begins.
    On the basis of our evaluation of the information presented in the 
petition and in our files, we determined that the petition presents 
substantial information to indicate that listing least chub as a 
threatened or endangered species may be warranted due to water

[[Page 61012]]

withdrawal and diversion. However, a great deal of uncertainty exists 
regarding the long-term effects of the groundwater pumping proposal for 
aquifers and surface waters in Utah's West Desert. Numerous models and 
studies are underway that should provide additional information that 
would enable us to evaluate effects.
    The GWD project is anticipated to be completed in January 2014 
(SNWA 2007, pp. 4-11). Prior to its completion, baseline data 
collection and research on biologic and hydrologic impacts will 
continue. Despite lack of specific data at this time, the level of 
concern regarding negative impacts to spring discharge rates, and 
ultimately least chub habitats, from groundwater pumping is high.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petition states the overutilization for commercial, 
recreational, scientific or educational purposes does not currently 
pose a threat to least chub.

C. Disease or Predation

    The petitioners document that where nonnative fishes have been 
introduced, least chub are unlikely to persist (Osmundson 1985, p. 2; 
Hickman 1989, pp. 2-3, 9). Introduced game fishes, including largemouth 
bass (Micropterus salmoides), rainbow trout (Oncorhynchus mykiss), 
common carp (Cyprinus carpio), and brook trout (Salvelinus fontinalis), 
are predators on least chub, and these species have been stocked into 
least chub habitats (Workman et al. 1979, pp. 1-2, 136; Sigler and 
Sigler 1987, p. 183; Osmundson 1985, p. 2; Crist 1990, p. 5).
    The petitioners note that mosquitofish (Gambusia affinis), in 
particular, are a direct threat because of aggressive predation on 
least chub eggs and young (Sigler and Sigler 1987, p. 183; Sigler and 
Miller 1963, p. 92). They indicate that population declines at Mona 
Springs (Hines et al. 2008, p. 34) and Lucin Pond (Thompson 2005, p. 4) 
have been directly attributed to the presence of mosquitofish.
    The petitioners note that disease and incidence of parasitism are 
not major factors affecting least chub. The parasite blackspot (Neascus 
cuticola) is known to be present in the Leland Harris population. 
Infested least chub examined to date have appeared to be robust and in 
good condition (Bailey et al. 2005, p. 21).
    We find that the petition presents substantial information 
indicating that nonnative species, particularly mosquitofish, are a 
predation threat to least chub in wild and translocated populations. 
Wasatch Front populations are currently impacted the most by nonnative 
species. The Mona Springs population is near extirpation (Hines et al. 
2008, p. 34) due to the invasion of mosquitofish. The nonnative fathead 
minnow (Pimephales promelas) is prominent at the Mills Valley site, and 
sunfish (Lepomis sp.) and common carp also are present; however, no 
effects have been observed to the least chub population (Hines et al. 
2008, p. 43). Rainbow trout and common carp have been captured at Clear 
Lake, and other nonnative species may be present; these species do not 
appear to be affecting the least chub population.
    Two efforts to translocate least chub to Fish Springs National 
Wildlife Refuge failed as a result of predation (and competition) by 
mosquitofish. A similar translocation on Antelope Island also failed as 
a result of predation by mosquitofish.
    The Least Chub Conservation Team implements ongoing efforts to 
prevent the introduction of nonnative species into least chub habitats. 
The Policy for Fish Stocking and Transfer Procedures includes protocols 
for the introduction of nonnative species, including game, and is 
adhered to by UDWR. All stocking actions must be consistent with 
ongoing recovery and conservation actions for Utah Sensitive Species 
(UDWR 1997, p. 19).
    In addition, the Least Chub Conservation Team (LCCT) has attempted 
mechanical removal of mosquitofish from occupied least chub habitats, 
most intensively at the Mona Springs complex. The least chub population 
at Mona Springs has been steadily declining since 1999. UDWR made 
extensive efforts to mechanically remove mosquitofish at this site for 
3 consecutive years, but even after 95 percent removal, the population 
recovered within a year (Hines et al. 2008, p. 32). Least chub at this 
location are now near extirpation (Hines et al. 2008, p. 31). A 
treatment for mosquitofish at Water and Deadman Springs on the Fish 
Springs National Wildlife Refuge was conducted in 1995 and 1996 through 
a combination of Rotenone application and draining the ponds. Least 
chub were then transplanted into the ponds, but re-invasion by 
mosquitofish resulted in transplant failure (Wilson and Whiting 2002, 
p. 4; Wilson and Mills 2004, pp. 4-5).
    In 2002, a Memorandum of Understanding (MOU) between UDWR and 
Mosquito Abatement Districts was finalized in order to reduce the 
spread of mosquitofish in Utah. The Mosquito Abatement Districts are 
now restricted to stocking in ornamental ponds. In 2008, UDWR and the 
Mosquito Abatement Districts of Salt Lake and Davis Counties will 
conduct pilot studies to determine the effectiveness of replacing 
mosquitofish with least chub for mosquito control purposes; however, 
this has not yet been completed.
    Despite efforts to monitor and remove mosquitofish, this nonnative 
species continues to be a predation threat (as well as a competitor; 
see Factor E) to the least chub. At some sites, such as Mona Springs, 
the threat is large enough that extirpation of least chub populations 
is possible. On the basis of our evaluation of the information 
presented in the petition, we find that the petition presents 
substantial information indicating that listing the least chub as a 
threatened or endangered species may be warranted due to the presence 
and potential spread of nonnative predatory species in least chub 
habitats.

D. Inadequacy of Existing Regulatory Mechanisms

    The petition reviews the legal authorities of each Federal agency 
relative to providing protection for the least chub, including the 
Service, BLM, and U.S. Army Corps of Engineers (Corps). The petitioners 
indicate that State, Tribal, and local programs are inadequate 
substitutes for Federal protection under the Act (Center for Biological 
Diversity v. Gale Norton, CV 01-409 TUC DCB, Jan. 13, 2003; Doremus and 
Page 2001, p. 1266). They acknowledge other agencies that contribute to 
the LCCAS, but have no regulatory authority, including BOR, URMCC, and 
the Central Utah Water Conservancy District.
    The petition indicates that the Service has no specific authority 
to take actions for recovery of least chub. Consideration or 
implementation of Service recommendations is discretionary. The 
petition states that management of least chub habitat on BLM lands is 
likely inadequate to prevent further decline of the species in Snake 
Valley because, regardless of the Federal Land Policy and Management 
Act (43 U.S.C. 1701 et seq.) and the National Environmental Policy Act 
(42 U.S.C. 4231 et seq.), impacts continue to occur to least chub 
sites. The Corps administers issuance of dredge and fill permits under 
section 404 of the Clean Water Act (33 U.S.C. 1251 et seq.). These 
permits regulate a wide variety of activities in streams and wetlands 
in both the historic and extant range of least chub. Under the 
regulations and policies governing implementation of this program, 
there is substantial latitude for allowing destruction and degradation 
of stream

[[Page 61013]]

habitats, including those that could potentially support least chub.
    The least chub is currently classified in the State of Utah 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 (UDWR 2005, pp. 5-3).
    The petitioners review the extensive efforts of UDWR, as a result 
of the LCCAS, to implement conservation measures for the least chub. 
They compare proposed measures in the LCCAS to completed conservation 
measures of habitat enhancement and protection, restoration of 
hydrologic conditions, nonnative control, range expansion, monitoring, 
mitigation, regulation, and information and education programs. The 
petitioners acknowledge progress made in all categories, but conclude 
that it is not adequate; despite the extensive efforts and new 
information on the species, the status of the least chub has not 
substantially improved since it was determined warranted for listing in 
1995.
    Although the least chub does not have protection under the Act, 
conservation provisions have been accomplished. The Service is 
represented on the LCCAS Technical Team, and we evaluate the progress 
of actions to protect the species. BLM also participates on the LCCAS 
Technical Team and assists in on-the-ground projects, such as fencing 
and habitat restoration, and has attached conservation measures to 
leases in areas of occupied least chub habitats.
    UDWR, through coordinated efforts by the Least Chub Conservation 
Team, has implemented site-specific habitat enhancement and restoration 
projects that include land acquisition, conservation easements, 
landowner agreements, bank stabilization, nonnative vegetation removal, 
fencing to exclude livestock, dredging, and water line repairs (Hines 
et al. 2008, pp. 22-24). Hydrologic conditions of extant least chub 
population habitats in Snake Valley have been protected by the UDWR. 
For example, in 2007, UDWR purchased water rights in Foote Reservoir to 
maintain water levels at Bishop and Twin Springs (Hines et al. 2008, p. 
23).
    Efforts also have been made to protect and increase the long-term 
viability of least chub populations. Portions of five of the six wild 
least chub populations (Bishop Springs, Mills Valley, Mona Springs, 
Clear Lake, and Leland Harris) have been relocated to new sites to 
provide genetic refuge (Hines et al. 2008, p. 20). In addition, two 
fish hatcheries harbor brood stock for use in ongoing relocation 
efforts and four display/educational populations exist.
    To date, BLM has demonstrated support for least chub conservation 
by requiring lease stipulations that avoid drilling in least chub 
habitats. UDWR has completed conservation measures within existing 
regulatory frameworks, such as acquiring water rights, purchasing land, 
and implementing habitat restoration. Mosquito Abatement Districts are 
now incorporating least chub conservation needs into mosquito control 
programs by removing mosquitofish as the primary control mechanism and 
cooperating in research efforts.
    Despite extensive efforts, regulatory mechanisms have not been able 
to ameliorate the threat from nonnative species, and State water 
regulations are not specific enough to ensure long-term viability of 
the least chub. We conclude that the petition presents substantial 
information to indicate that listing least chub as a threatened or 
endangered species may be warranted due to inadequacy of existing 
regulatory mechanisms.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    The petitioners state that other natural and manmade threats to the 
species include: (1) Competition from nonnative species; (2) 
hybridization; (3) mosquito abatement programs; (4) stochastic 
disturbance and population isolation; (5) drought and climate change; 
and (6) cumulative effects.
Competition from Nonnative Species
    The petitioners indicate that nonnative fishes, including 
mosquitofish, rainwater killifish (Lucania parva), and plains killifish 
(Fundulus zebrinis), have been released into least chub habitats. These 
species have similar diets to the least chub and are considered 
competitors.
    Nonnative fishes exist in least chub habitats. Mosquitofish, in 
addition to being a predator on least chub eggs and young, are a 
significant competitor to adult least chub for food sources. Population 
declines at Mona Springs and Lucin Pond have been directly attributed 
to the presence of mosquitofish (Hines et al. 2008, p. 34; Thompson 
2005, p. 4). See Factor C (predation) for a discussion of the efforts, 
mostly unsuccessful, to remove and prevent reinvasion of nonnative fish 
in least chub habitats. We find that the petition presents substantial 
information to indicate that listing least chub as a threatened or 
endangered species may be warranted due to competition from nonnative 
fish.
Hybridization
    The petition notes that hybridization may occur in compromised 
habitats. Hybrid introgression of least chub with Utah chub (Gila 
atraria), and with speckled dace (Rhinichthys osculus), has been 
reported (Miller and Behnke 1985, pp. 509-515). In complex habitats, 
reproductive isolating mechanisms can be eliminated as a result of 
habitat alteration and degradation; overlaps of reproductive niches and 
breakdowns of behavior due to overcrowding then occur (Crawford 1979, 
p. 74; Lamarra 1981, p. 7). Least chub hybrids have been reported from 
springs near Callao, Utah, where least chub once existed (Miller and 
Behnke 1985, p. 510).
    Recent molecular diversity studies on existing least chub 
populations indicate that currently no evidence of hybridization 
between least chub and Utah chub exists, and suggest that previous 
hybridization reports may have been due to a misidentification of 
specimens (Mock and Miller 2003, p. 10). The information provided by 
the petitioners does not present substantial information to indicate 
that listing the least chub may be warranted due to hybridization.
Mosquito Abatement Programs
    The petition indicates that, although BLM has rejected Juab 
County's request for implementing a mosquito control spraying program 
on BLM administered lands, the spraying may still occur on private 
lands. The least chub may be affected because mosquito larvae are a 
major food item in the least chub diet.
    Least chub have been shown to be opportunistic feeders and use 
available food items, including algae, diatomaceous material, midges, 
copepods, and ostracods (Sigler and Sigler 1987, p. 92; Hickman 1989, 
p. 8) depending on seasons and habitats (Crist and Holden 1980, p. 808; 
Lamarra 1981, p. 5). As previously stated, an MOU between UDWR and 
Mosquito Abatement Districts was finalized in order to reduce the 
spread of mosquitofish in Utah. In 2008, UDWR and the Mosquito 
Abatement Districts of Salt Lake and Davis Counties will conduct 
studies to determine the effectiveness of replacing mosquitofish with 
least chub for mosquito control purposes; however, studies have not 
been completed. The petitioners conclude that effects of a mosquito 
control program on least chub are unknown. The petitioners do not 
present substantial information to indicate that listing the least chub 
may

[[Page 61014]]

be warranted due to effects from mosquito abatement programs.
Stochastic Disturbance and Population Isolation
    The petition presents information relative to the limited 
distribution and isolation of remaining least chub populations. The 
petitioners cite literature on the risks to small, isolated 
populations, including environmental and demographic stochasticity 
(Lande 1993, pp. 911-917).
    Least chub populations are isolated, both naturally and as the 
result of human impacts. Habitat connectivity is absent among the three 
Wasatch Front populations as a result of past urban development. West 
Desert populations are similarly disconnected except in years of 
exceptionally high water. However, the LCCT team has been successful in 
protecting the remaining occupied sites. Translocation efforts have 
established five new sites in natural habitats (Hines et al. 2008, p. 
20). In addition, results of genetic studies indicate that ongoing 
translocation efforts have been successful in maintaining genetic 
diversity (Mock and Miller 2005, pp. 273-277). Therefore, although 
small, isolated populations will remain a conservation challenge, we 
find that the petitioners have not presented substantial information to 
indicate that listing the least chub may be warranted due to effects 
from stochastic disturbance and population isolation.
Drought and Climate Change
    The petition indicates that a prolonged drought has occurred in 
Utah and some least chub habitats, particularly the Gandy Salt Marsh 
complex, may have been compromised. The petition cites the effects of 
climate change on biodiversity (IPCC 2001, pp. 5, 16; Davenport et al. 
1998, pp. 229-238), and the combined effects of drought to least chub 
populations and habitats in Utah. The petitioners state that climate 
change, specifically increased global temperatures, may be a more 
serious long-term threat to least chub than drought. They indicate that 
the effects of increased global temperatures include decreased duration 
and depth of winter snowfall (IPCC 2001, pp. 6, 9); earlier spring 
runoff and decreased water availability; decreased productivity and 
cover of herbaceous vegetation, resulting in increased soil erosion; 
and unprecedented rates of vegetation shifts due to die off, especially 
along boundaries of semi-arid ecosystems (Davenport et al. 1998, p. 
231). These changes may pose threats to native aquatic species as the 
quality and quantity of aquatic, riparian, and mesic upland ecosystems 
decline with decreased water availability.
    The petitioners present no direct link between climate change and 
the least chub, and we have no information in our files to substantiate 
their claims. Therefore, we find that the petitioners have not 
presented substantial information to indicate that listing the least 
chub may be warranted due to effects from climate change.
    Drought has been documented periodically within the range of the 
least chub, and is likely currently affecting the species. However, the 
species has continued to exist despite periods of natural drought, and 
on its own, this is not considered a significant threat to the species. 
During periods of drought, farmers and ranchers rely more heavily on 
water sources for irrigation purposes, and this factor combined with 
drought has likely led to the loss of several springs in the Snake 
Valley. However, it is currently not possible to separate drought from 
water withdrawals in order to analyze it as a threat to the least chub. 
Therefore, we find that the petitioners have not presented substantial 
information to indicate that listing the least chub may be warranted 
due to effects from drought.
Cumulative Effects
    The petitioners indicate that many possible combinations of effects 
could cumulatively impact least chub populations. They discuss possible 
combined effects of climate change, drought, and aquifer depletions on 
the least chub and its habitats.
    We cannot predict the cumulative effects of climate change and 
drought on least chub at this time. In addition, because the effects of 
proposed groundwater withdrawals have not been determined, it is 
difficult to predict how the combination of those effects with 
potential climate change and drought would affect the least chub. 
Effects will be determined to some extent possibly by modeling efforts, 
and by the results of implementation and monitoring of future 
groundwater withdrawals. While potential combinations of negative 
impacts are a concern for the least chub, we find that the petitioners 
have not presented substantial information to indicate that listing the 
least chub may be warranted due to the cumulative effects of climate 
change, drought, and aquifer depletions.
Finding
    We reviewed the petition, supporting information provided by the 
petitioners, and information in our files and evaluated that 
information to determine whether the sources cited support the claims 
made in the petition. We find the petitioners presented substantial 
information under Factor A (Present or threatened destruction, 
modification, or curtailment of habitat or range) indicating that 
listing the least chub as threatened or endangered under the Act may be 
warranted due to water withdrawals and diversions. While uncertainty 
exists on the magnitude of effects to the least chub from proposed 
groundwater pumping, concern regarding the six extant, wild populations 
is sufficient to warrant further analysis.
    We find that the petitioners presented substantial information 
under Factors C (Disease or Predation) and E (Other Natural or Manmade 
Factors Affecting the Species' Continued Existence) indicating that 
listing the least chub as threatened or endangered under the Act may be 
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 may be extirpated due to mosquitofish. 
Of the six natural populations, five have nonnative species present and 
of five refuge sites, two currently have mosquitofish present.
    We find that the petitioners presented substantial information 
under Factor D (Inadequacy of Existing Regulatory Mechanisms) 
indicating that listing the least chub as threatened or endangered 
under the Act may be warranted due to inadequacy of existing 
regulations. Regulatory mechanisms may not be adequate to ameliorate 
the threat from nonnative species, and State water regulations are not 
specific enough to ensure long-term viability of the least chub.
    Based on our consideration of the information provided in the 
petition, and in accordance with recent applicable court decisions 
pertaining to 90-day findings, we find that the petition presents 
substantial scientific information indicating that listing the least 
chub may be warranted. Our process for making this 90-day finding under 
section 4(b)(3)(A) of the Act is limited to a determination of whether 
the information in the petition presents ``substantial scientific and 
commercial information,'' which is interpreted in our regulations as 
``that amount of information that would lead a reasonable person to 
believe that the measure proposed in the petition may be warranted'' 
(50 CFR 424.14(b)).

[[Page 61015]]

Therefore, we are initiating a status review to determine if listing 
the species is warranted. To ensure that the status review is 
comprehensive, we are soliciting scientific and commercial information 
regarding the least chub.
    It is important to note that the ``substantial information'' 
standard for a 90-day finding is in contrast to the Act's ``best 
scientific and commercial data'' standard that applies to a 12-month 
finding as to whether a petitioned action is warranted. A 90-day 
finding is not a status assessment of the species and does not 
constitute a status review under the Act. Our final determination as to 
whether a petitioned action is warranted is not made until we have 
completed a thorough status review of the species, which is conducted 
following a positive 90-day finding. Because the Act's standards for 
90-day and 12-month findings are different, as described above, a 
positive 90-day finding does not mean that the 12-month finding also 
will be positive.
    We encourage interested parties to continue gathering data that 
will assist with the conservation and monitoring of the least chub. The 
petitioners requested that critical habitat be designated for this 
species. If we determine in our 12-month finding that listing the least 
chub is warranted, we will address the designation of critical habitat 
at the time of the proposed rulemaking.

References Cited

    A complete list of all references cited in this document is 
available upon request from the Utah Ecological Services Field Office 
(see the FOR FURTHER INFORMATION CONTACT section).

Author

    The primary authors of this document are staff of the Utah 
Ecological Services Field Office (see the FOR FURTHER INFORMATION 
CONTACT section).

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: October 7, 2008.
Paul R. Schmidt,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E8-24467 Filed 10-14-08; 8:45 am]
BILLING CODE 4310-55-P