[Federal Register Volume 60, Number 189 (Friday, September 29, 1995)]
[Proposed Rules]
[Pages 50518-50530]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: X95-20929]



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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AC91


Endangered and Threatened Wildlife and Plants; Proposal To 
Determine the Least Chub (Iotichthys phlegethontis) an Endangered 
Species With Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes to 
determine the least chub (Iotichthys phlegethontis) to be an endangered 
species and to designate critical habitat pursuant to the Endangered 
Species Act of 1973, as amended. This small monotypic minnow is endemic 
to the Bonneville Basin in Utah where it was once common and widely 
distributed. Populations of least chub have declined, and it now only 
exists within Snake Valley in western Utah. The continuing decline in 
range and abundance of the least club has been attributed to 
competition and predation from nonnative species and habitat loss and 
alteration.

DATES: Comments from all interested parties must be received by 
November 28, 1995. Public hearing requests must be received by November 
13, 1995.

ADDRESSES: Comments and materials concerning this proposal should be 
sent to the Field Supervisor, U.S. Fish and Wildlife Service, Lincoln 
Plaza, Suite 404, 145 East 1300 South, Salt Lake City, Utah 84115. 
Comments and materials received will be available for public 
inspection, by appointment, at the above address during normal business 
hours.

FOR FURTHER INFORMATION CONTACT: Robert D. Williams at the above 
address, telephone 801/524-5001.

SUPPLEMENTARY INFORMATION:

Background

    The least chub, Iotichthys phlegethontis, is an endemic minnow 
(Family Cyprinidae) of the Bonneville Basin of Utah, which is located 
in the Great Basin of southwestern North America. E.D. Cope described 
the least chub (Clinostomus phlegethontis) from specimens collected in 
the Beaver River in 1872 by Dr. H.C. Yarrow and H.W. Henshaw (Cope 
1874, cited in Cope and Yarrow 1875). However, the scientific name has 
been revised several times: from the genus Clinostomus to Gila (Cope 
and Yarrow 1875), to Phoxinus (Jordan and Gilbert 1883, cited in Jordan 
and Evermann 1896), to Hemitremia (Jordan 1891), to Leuciscus subgenus 
Iotichthys (Jordan and Evermann 1896), and finally to the monotypic 
genus Iotichthys (Jordan et al. 1930, cited in Hickman 1989; Robins 
1991).
    As suggested by its common and scientific names, the least chub is 
a small fish (<45 mm, 2.5 in.) that is identified by an upturned or 
oblique mouth (clinostomus), large scales, and absence of a lateral 
line (rarely with one or two pored scales). It was a deeply compressed 
body, the dorsal origin lies behind the insertion of the pelvic fin, 
and the caudle peduncle is slender. Dorsal fin rays number eight 
(rarely nine), and it has eight anal fin rays. The pharyngeal teeth 
(2,5-4,2) are in two rows (Jordan and Evermann 1896; Page and Burr 
1991).
    The colorful least chub has a gold stripe along its blue sides with 
white-to-yellow fins. Males are olive-green above, steel-blue on the 
sides, and have a golden stripe behind the upper end of 

[[Page 50519]]
the gill opening. The fins are lemon-amber, and sometimes the paired 
fins are bright golden-amber. Females and young are pale olive above, 
silvery on the sides, and have watery-white fins; their eyes are 
silvery, with only a little gold coloration, rather than golden as in 
the males (Sigler and Miller 1963; Page and Burr 1991).
    Sigler and Sigler (1987) considered the least chub to be a short-
lived and slow-growing species: least chub mature within 1 year and 
rarely live beyond 3 years of age. Of 218 fish aged by various 
investigators, less than 1 percent of the fish reached 4 years of age, 
and only 2 fish reached a total length of 7.6 cm (3 in.). A least chub 
of average size would be about 3.3 cm (1.3 in.) and weigh 0.57 g (0.02 
oz) (Sigler and Workman 1975: Workman et al. 1976; Crawford 1979).
    Least chub begin spawning in the spring when water temperatures 
reach about 16  deg.C (60  deg.F; Sigler and Sigler 1987). The least 
chub is a partial and intermittent spawner. Crawford (1979) found that 
least chub females produced only a few eggs at any time but release 
eggs over an extended period. The number of eggs produced at any one 
time is variable and may range from about 300 to 2,700 (Sigler and 
Sigler 1987). Although the peak spawning activity occurs in May, the 
reproductive season lasts from April to August, and perhaps longer 
depending on environmental conditions. The least chub has evolved this 
reproductive strategy (i.e., repetitive spawning during one season and 
of spreading the spawn over many weeks) perhaps as an adaptation to 
unpredictable environmental changes that are present in desert 
habitats. The least chub presumably initiates spawning in response to 
increases in water temperature and photoperiod, which may act in 
concert with other environmental and physiological factors, including 
exposure to direct sunlight (Crawford 1979; Sigler and Sigler 1987).
    The least chub releases its sex products over vegetation (Crawford 
1979). The adhesive eggs then sink and usually attach to the underwater 
vegetation. Fertilized eggs hatch in about 2 days at water temperatures 
of 22  deg.C (72  deg.F; Crawford 1979). The presence of submerged 
vegetation provides an important habitat for eggs and young larvae by 
furnishing needed oxygen and food (Crist and Holden 1980).
    Common foods of the least chub include algae (Chlorophyta and 
Chrysophyta) midges (Chironomidae), and microcrustaceans; but they also 
eat other items (Sigler and Sigler 1987). Of 185 least chub taken from 
27 springs, 121 stomachs contained 14 food types including algae, 
crustaceans, and insects (Workman et al. 1979). It also is believed 
that mosquito larvae make up a significant portion of their diet 
(Sigler and Miller 1963; Sigler and Workman 1975). Workman et al. 
(1979) noted that least chub diet changed throughout the year, and 
vegetation was more important during winter months.
    The least chub was once widely distributed within the Bonneville 
Basin of northwestern Utah. The fish occupied a variety of habitats 
including streams, springs, and ponds, and it was classified as 
``excessively common'' in its preferred habitats (Jordan and Everman 
1896). Yarrow and Henshaw found least chub in the Beaver River (Cope 
and Yarrow 1875). Jordan (1891, cited by Jordan and Evermann 1896) 
collected least chub from ponds near the mouth of the Provo River. 
Jordan and Evermann (1896) stated that least club occurred in 
``tributaries of Great Salt Lake and Sevier Lake,'' Least chub also 
have been observed in Utah Lake, Beaver River, Parowan Creek, Clear 
Creek, and the Provo River (reviewed by Sigler and Miller 1963; Hickman 
1989). More recently, C.D. Barbour, University of Utah, (in litt. 1970) 
collected least chub from the Gandy Salt Marsh Complex in the Snake 
Valley. In 1970, R.R. Miller, University of Michigan, (in litt. 1971), 
found large numbers of least chub in the Leland Harris Springs complex, 
also in Snake Valley.
    A decline in distribution and abundance of the least chub was first 
noted in the 1940's and 1950's (Baugh 1980). Hubbs and Miller collected 
least chub on trips into Utah during the 1940's and 1950's, and also 
noted a decrease in abundance (Holden et al. 1974). The fish is now 
restricted to the Snake Valley of the Bonneville Basin.
    Least chub occur on a mixture of Federal, State, and private lands 
at five locations in the Snake Valley. Small numbers of least chub 
exist in two isolated springs: Central Spring (Bishop Spring Complex, 
Millard County) and Miller Spring (Juab County), but the fish is most 
abundant in Leland Harris Spring Complex (Juab County) and Gandy Salt 
Marsh Complex (Millard County). Recent surveys by the Utah Divison of 
Wildlife Resources (UDWR), Salt Lake City, (in litt. 1993) indicated 
that some least chub in Snake Creek, south of Grandy Salt Marsh. 
However, no studies have been conducted to determine the distribution, 
abundance, or status of this Snake Creek population (L. Lentsch, UDWR, 
pers. comm. 1993).
    Historically, the least chub inhabited a variety of habitat types 
in different environments (Lamarra 1981; Sigler and Sigler 1987). Least 
chub now occupy springs, marshes and pools, and stream habitats. 
Osmundson (1988) reported collections of least chub from 38 sites, and 
these fish were captured in pools from 0.3 to 260 m<SUP>3 (3 to 2,800 
ft<SUP>2) in size and with water depths of 0.1 to 3.6 m (0.4 to 12ft). 
In some of these habitats, certain environmental parameters fluctute. 
The springs exhibit cool stable temperature, relatively low 
conductivity, and little variation in dissolved oxygen content. The 
marsh and pool environments exhibit extreme diurnal fluctuations in 
dissolved oxygen, and water temperatures that may vary between 15 and 
32  deg.C (59-90  deg.F) (Crist and Holden 1980; Lamarra 1981). 
Seasonal water quality changes in the marshes and stream segments 
result in fish movement back and forth between different hibitat types, 
especially between the springs and marshes (Crist and Holden 1980).
    Vegetation is an important habitat component for the least chub 
(Crist and Holden 1980), and Sigler and Workman (1975) reported that 
least chub habitat included aquatic plants that were ``plentiful and 
provided excellent cover.'' Water parsnip (Berula erecta), wire rush 
(Juncus balticus), and algae are common in and around the springs and 
marshes that are inhabited by the fish (Sigler and Workman, 1975). 
However, many other plants occur in areas occupied by the fish 
including Chara sp., duckweed (Laemna sp.), watercress (Nasturtium 
sp.), bulrushes (Sciurpus sp.), cattails (Typha sp.), and sedges 
(Cyperus sp.) (Sigler and Sigler 1987).
    Least chub has not been collected outside of Snake Valley since 
1965 (Hickman 1989). They continue to decline in Snake Valley, and 
studies conducted in the past 15 years indicate a steady decline in 
their distribution and abundance. Workman et al. (1979) collected least 
chub from 36 sites in 5 major spring complexes in Snake Valley, but 
Osmundson (1985) found it in only 2 of 5 complexes where it previously 
existed. Crist (1990) reported that least chub were extirpated from 
springs on the Bagley Ranch and the Redden Springs Complex. Least chub 
numbers are now declining within the Gandy Salt Marsh and Leland Harris 
Spring Complex. Recent collections by UDWR personnel indicate that 
least club occurs in only 3 of 5 springs sampled in the Leland-Harris 
Complex and 6 of 12 springs in the Grandy Salt Marsh. A continuing 
decline of the least chub has prompted the American Fisheries Society 
to recognize it as a threatened species (Deacon et al. 1979).

[[Page 50520]]

    As with other endemic southwestern fishes (Courtenay and Stauffer 
1984; Meffe 1985; Schoenherr 1991), predation by introduced nonnative 
fishes have caused the decline of the least chub. Largemouth bass, 
rainbow trout, common carp, and brook trout have been regularly stocked 
by government agencies and private citizens into least chub habitat 
(Workman et al. 1979; Sigler and Sigler 1987; Osmundson 1985). Hickman 
(1989) considered least chub to be ``constantly threatened'' by the 
introduction of these gamefish species. However, other nonnative 
species also prey upon or compete with the least club, including the 
mosquitofish (Gambusia affinis) and rainwater killifish (Lucania 
parva). Introduction of fishes into least chub habitat probably 
contributed to the extirpation of least chub outside of Snake Valley, 
since few least chub are present in spring complexes in Snake Valley 
where nonnative fishes have been introduced (Osmundson 1985; Shirley, 
in litt. 1989).
    Direct, physical habitat loss and habitat degradation also are 
factors in the decline of the least chub (Holden et al. 1974; Hickman 
1989; Crist 1990). In spring complexes that contain least chub, habitat 
degradation caused by livestock trampling could be a threat although no 
studies of the impact of livestock on the springs of Snake Valley have 
been conducted to date.
    Recent oil and gas exploration and production activity in the West 
Desert area may result in increased degradation and/or impacts to least 
chub habitat. Exploration results in increased road access to sensitive 
areas while surface activities associated with drilling, including 
drilling site preparation under water hauling, may impact water 
quality. Drilling activities also may release drilling fluids into the 
aquifer or may fracture underground geologic features that are 
associated with springs.
    Water withdrawals also are a potential threat to the least chub. 
Not only can reduced water supply diminish the amount of least chub 
habitat, and thus the capacity of an area to support least chub, but 
lowered levels may cause niche overlaps with other species. These 
overlaps may increase hybrid introgression and interspecific 
competition (Crawford 1979; Lamarra 1981). Maintenance of certain water 
levels is very important to least chub because these levels must be 
high enough to allow the fish to migrate between springs and 
surrounding marsh areas as environmental conditions change. 
Additionally, maintenance of water levels and discharge volumes is 
critical in preserving natural sediment transport processes, thereby 
maintaining underwater habitat configurations and reducing aquatic 
vegetation encroachment into sensitive spring areas.
    Present water withdrawals from surface and underground sources are 
estimated at 10 percent of the total yearly recharge rate (Van Pelt 
1992). These rates do not appear to be threatening to least chub 
habitat. However, additional proposed wells in the southern part of 
Snake Valley and surrounding areas could lower the water table, 
resulting in drying up or lowering the water level in springs and 
marshes populated by least chub. These springs are dependant on 
underground water sources that flow from the Deep Creek Mountains to 
the Snake Valley (M. Barber, Bureau of Land Management (BLM), in litt. 
1991; Brothers et al. 1993). It is important to note that all surface 
streams from the Deep Creek Mountains are currently diverted for 
agricultural use.
    Several efforts to reintroduce least chub into historic habitat 
have been attempted. In 1979, least chub were introduced into a pond 
near Salt Lake City, Utah. The following year, young least chub were 
collected, verifying successful reproduction. However, introduction of 
nonnative fishes, combined with flooding of the pond by the Great Salt 
Lake, eliminated this successfully reintroduced population. Two other 
attempts to reintroduce least chub were not successful; the reasons for 
these failures are not well understood, but competition and/or 
predation with nonnative fishes offer a partial explanation (Crist 
1990). Additional investigations are necessary prior to future 
reintroduction attempts, including reasons for past successes and 
failures, and the need to experiment with several reintroduction 
techniques. Both the UDWR and BLM are working on developing management 
plans that will address these reintroduction issues (L. Lentsch, UDWR, 
pers. comm., 1994; R. Fike, BLM, pers. comm., 1994).

Previous Federal Action

    The Fish and Wildlife Service (Service) has conducted three status 
reviews for the least chub and have prepared two status reports. In 
1980, the Service reviewed existing information on the least chub and 
determined that there was insufficient data to warrant its listing as 
endangered or threatened. On December 30, 1982, the Service classified 
the fish as a category 2 candidate species (47 FR 58454). After 
preparation of a 1989 status report, the Service reclassified the least 
chub as a category 1 candidate species (54 FR 554; January 6, 1989). 
The Service continues to evaluate information and data concerning 
population declines and increasing threats, and has determined that 
listing the least chub as endangered or threatened is warranted.

Summary of Factors Affecting the Species

    Section 4(a)(1) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), and regulations (50 CFR Part 424) 
promulgated to implement the listing provisions of the Act set forth 
the procedures for adding species to the Federal lists. 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). These factors 
and their application to the least chub (Iotichthys phlegethontis) are 
as follows:
    A. The threatened destruction, modification, or curtailment of its 
habitat or range. The least chub was once widely distributed within the 
Bonneville Basin of northwestern Utah and occupied many streams, 
springs, and ponds. Yarrow and Henshaw found least chub in the Beaver 
River (Cope and Yarrow 1875). Jordan (1891, cited by Jordan and 
Evermann 1896) collected least chub from ponds near the mouth of the 
Provo River. Jordan and Evermann (1896) stated that least chub occurred 
in ``tributaries of Great Salt Lake and Sevier Lake.'' More recently, 
least chub were observed in Utah Lake, Beaver River, Parowan Creek, 
Clear Creek, and the Provo River (reviewed by Sigler and Miller 1963; 
Hickman 1989). However, least chub have not been collected outside of 
Snake Valley since 1965 (Hickman 1989).
    Least chub populations in Snake Valley are not stable and studies 
conducted in the past 15 years indicate a steady decline in their 
distribution and numbers. Workman et al. (1979) collected least chub 
from 36 sites spread throughout 5 major spring complexes in Snake 
Valley. A few years later, Osmundson (1985) found least chub in only 
two of the five complexes. Further surveys have confirmed that least 
chub has been extirpated from springs on the Bagley Ranch and the 
Redden Springs Complex (Crist 1990). Recent data suggest that least 
chub numbers are now declining within the Gandy Salt Marsh and Leland 
Harris Spring Complex. Personnel from UDWR found least chub only in 3 
of 5 springs sampled in the Leland-Harris Complex and 6 of 12 springs 
in the Gandy Salt Marsh. Some least chub have recently been discovered 
in Snake Creek, south of Gandy Salt Marsh. However, no studies 

[[Page 50521]]
have been conducted to determine the distribution, abundance, or status 
of this Snake Creek population (L. Lentsch, pers. comm., 1993). Service 
biologists believe that the numbers of least chub at Snake Creek are 
insufficient to reverse this downward trend in its numbers.
    Habitat loss and degradation have been indicated as major causes of 
the least chub's decline (Holden et al. 1974; Hickman 1989; Crist 
1990). Although no studies have been made of the springs in Snake 
Valley, numerous other reports link livestock trampling and grazing 
with fish habitat degradation in streams and springs (Duff 1977; May 
and Somes 1981; Taylor et al. 1989; Bowen and Beauchamp 1992). The 
springs in the Snake Valley that are occupied by least chub are not 
protected from livestock. The BLM has one fenced exclosure in the Gandy 
Salt Marsh Complex and is considering a second exclosure to protect 
other springs (R. Fike, BLM, pers. comm., 1993).
    Crist and Holden (1990) and Lamarra (1981) indicated that water 
levels are important to least chub life history. The Las Vegas Valley 
Water District has requested a permit to drill a series of wells in the 
southern part of Snake Valley and surrounding areas (M. Barber, in 
litt. 1991). This could lower the water table significantly in Snake 
Valley, possibly drying up or lowering the water level in springs and 
marshes populated by least chub. These springs are totally dependent on 
underground water sources which flow from the Deep Creek Mountains to 
the west of Snake Valley. Other forms of water use within Snake Valley 
pose a minimal threat to least chub habitat at this time, and water 
withdrawals from surface and underground sources are estimated at 10 
percent of the total yearly recharge rate (Van Pelt 1992).
    B. Overutilization for commercial, recreational, scientific, or 
educational purposes. Some specimens have been collected for scientific 
and educational purposes (Sigler and Workman 1975; Workman et al. 1979; 
Crawford 1979; Osmundson 1985). However, no commercial or recreational 
uses for the least chub are known to exist. Overutilization for 
commercial or scientific purposes does not pose a threat to least chub.
    C. Disease or predation. Disease or incidence of parasitism 
presently are not major factors affecting the least chub. Workman et 
al. (1979) found a single parasite called blackspot (the metacercariae 
of the digenetic trematode) infesting the least chub. Black spot 
(Neascus cuticola) produces small, black-pigmented nodules on the skin, 
trunk musculature, and fins of fishes and is frequently encountered in 
the least chub, Utah chub (Gila atraria), and speckled dace 
(Rhinichthyes osculus). Workman et al. (1979) reported black spot 
infection rates for the least chub as 1-23 nodules per fish, and that 
the infection rate varied from area to area and with season (highest in 
late summer and lowest in winter). Despite this moderate infestation 
rate, all least chubs examined appeared robust and in good condition. 
This parasite is apparently restricted to certain spring and pond 
areas.
    Predation by nonnative fishes has been a major factor in the 
decline and extirpation of desert fishes in southwestern North America 
(Schoenherr 1981; Meffe 1985; Minckley et al. 1991). Hickman (1989) 
considered least chub to be ``constantly threatened'' by the 
introduction of nonnative species. Surveys of spring complexes indicate 
that where nonnative fishes were introduced, few if any least chub 
remain (Osmundson 1985; Shirley, in litt. 1989). Introduced game fishes 
which include largemouth bass, rainbow trout, common carp, and brook 
trout, are predators on least chub, and these species have been 
regularly stocked in least chub habitat (Workman et al. 1979; Sigler 
and Sigler 1987; Osmundson 1985; Crist 1990), no doubt contributing to 
the endangerment of least chub. In addition to game fish, other 
nonnative fishes also have been released into least chub habitat. Two 
fishes, the mosquitofish (Gambusia affinis) and rainwater killifish 
(Luciana parva), have similar diets to the least chub and are 
considered potential competitors. The mosquitofish poses a direct 
threat to the least chub because of its known aggressive predation on 
eggs and young of other fishes. Mosquitofish have been implicated in 
the decline of other desert fishes (Schoenherr 1981; Meffe 1985).
    Osmundson (1985) and Sigler and Sigler (1987) also indicated that 
frogs, ducks, gulls, herons and egrets also are potential predators on 
least chub. Under normal circumstances, predation from these sources 
probably would not injure healthy populations of least chub. However, 
the effect of predation from the above combined sources could cause 
further depletion of already fragile populations.
    D. The inadequacy of existing regulatory mechanisms. Although the 
State of Utah lists the least chub as a protected species, the Service 
believes that the present level of protection afforded by the State is 
not sufficient. The State does not allow taking of the species without 
permits, but it does not protect or control actions which cause harm to 
the species or its habitat. The continued introduction of nonnative 
predators into least chub habitat and adjacent areas is difficult to 
control, and the State's protection does not address this issue.
    The BLM has designated the Gandy Salt Marsh as an ``Area of 
Critical Environmental Concern (ACEC).'' This ACEC is inadequate in 
protecting the least chub because it does not prevent taking of the 
species. The establishment of an ACEC requires a management system 
which integrates the protection of riparian areas without infringement 
on ``traditional permitted uses'' (Van Pelt 1990). Accordingly, the 
Gandy Salt marsh ACEC does not prevent livestock gracing in and around 
least chub habitat and it does not extend over the fish's entire 
habitat. Finally, the ACEC is a BLM oil and gas leasing category 4, 
which normally closes the area to leasing. However, a clause was 
written into the BLM's Resource Management Plan which allows the 
District Manager to exempt the category 4 protections and to lease ACEC 
lands.
    E. Other natural or manmade factors affecting its continued 
existence. Declines in native desert fishes in the Southwest has been 
associated with the introduction and proliferation of nonnative fishes. 
These nonnative fishes have, in some documented instances, extirpated 
small desert fishes by direct competition and predation (Schoenherr 
1981; Meffe 1985; Minckley et al. 1991). The existence of small desert 
cyprinids, including the least chub, is presumably the result of a lack 
of other small competitors (Smith 1981; Minckley et al. 1991).
    Least chub coexist with other native fishes, which include the Utah 
chub and speckled dace. However, the tiny and reclusive least chub 
competes poorly with nonnative species such as mosquitofish and 
rainwater killifish. The mosquitofish, rainbow trout, and largemouth 
bass are considered to be direct predators (Sigler and Workman 1975; 
Crawford 1979; Sigler and Sigler 1987). Least chub do not build nests 
or protect their eggs. Instead, they lay their eggs upon vegetation 
where they and the newly hatched larvae are vulnerable to predation 
(Crawford 1979).
    Hybrid introgression between least chub and the Utah chub and 
speckled dace have been reported (Sigler and Sigler 1987). Reproductive 
isolating mechanisms have apparently broken down in some areas due to 
habitat alteration and degradation. This has resulted in overlaps of 
reproductive niches and breakdowns in behavior due to overcrowding 
(Crawford 1978; 

[[Page 50522]]
Lamarra 1981). Least chub hybrids have been reported from springs near 
Callao, Utah, where least chubs once existed. But no hybrids have been 
reported from Leland Harris Springs Complex where least chub habitat 
has not been greatly altered by humans (Lamarra 1981).
    Another potential threat to the least chub is a proposed mosquito 
abatement program for Juab County. The BLM has rejected the County's 
request to implement a mosquito control spraying program in marsh and 
spring areas on BLM administered lands (R. Fike, in litt. 1992). The 
rejection does not prevent the county from spraying on privately-owned 
lands. The effect of a mosquito control spraying program on the least 
chub is uncertain. Past studies (Workman et al. 1979) indicate that 
much of the least chub's diet is composed of insects, which includes 
mosquito larvae. To date, no studies have been undertaken to determine 
the effects of toxins on the chub or its environment.
    Due to the extremely limited distribution of this species, least 
chub are very susceptible to stochastic events. There are only five 
known populations of least chub, and each population is small. A single 
catastrophic event could destroy a significant portion of remaining 
least chubs, or one or more of their populations. These remaining 
populations are vital in maintaining the genetic diversity of the 
species.
    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by this species in determining whether to propose 
this listing action. Based on this evaluation, the preferred action is 
to list the least chub as endangered since this fish is restricted to 
only five known populations. Habitat loss and degradation continue to 
reduce its numbers in these remaining populations. Without additional 
protection of its habitat, continued degradation by livestock will 
result in a further reduction in its numbers. Competition and predation 
by other nonnative fishes pose severe threats to the remaining 
populations. The least chub is highly susceptible to additional habitat 
degradation and to habitat and population losses. For the reasons 
discussed below, the Service also is proposing to designate critical 
habitat for the least chub.

Critical Habitat

    Critical habitat is defined in section 3 of the Act as: ``(i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a species at the time it is listed * * *, 
upon a determination by the Secretary that such areas are essential for 
the conservation of the species.''

``Conservation'' means the use of all methods and procedures needed to 
bring the species to the point at which listing under the Act is no 
longer necessary.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations require that, to the maximum extent prudent and 
determinable, the Secretary designate critical habitat at the same time 
the species is determined to be endangered or threatened. Critical 
habitat is being proposed for the least chub to include the following 
areas in Utah.
    Northern Snake Valley Group including: Redding Springs Complex 
(Tooele County) and Bagley Ranch Springs Complex (Tooele and Juab 
Counties).
    Southern Snake Valley Group including: Miller Spring (Juab County); 
Leland Harris Springs Complex (Juab and Millard Counties); Gandy Salt 
Marsh Complex (Millard County); and Bishop Springs Complex (Millard 
County).
    Tule Valley Group including: Coyote Spring Complex (Millard 
County); Willow Spring (Millard County); Tule Springs Complex (Millard 
County); and South Tule Springs (Millard County). Legal descriptions 
for these areas are provided in the ``Proposed Regulation Promulgation 
section.
    In determining the areas to designate as critical habitat for a 
species, the Service considers those physical and biological attributes 
that are essential to species conservation. In addition, the Act 
stipulates that the areas containing these elements may require special 
management consideration or protection. Such physical and biological 
features are stated in 50 CFR 424.12 and include, but are not limited 
to, the following items:
    (1) Space for individual growth and for normal behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, rearing of offspring, 
germination, or seed dispersal; and generally,
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographical and ecological 
distributions of a species.
    In designating critical habitat, the Service is concerned with 
constituent elements within the defined areas that are essential to the 
conservation and recovery of the species. The areas proposed as 
critical habitat for the least chub provide the necessary constituent 
elements determine essential to the survival and recovery of the least 
chub. They include the following:

--adequate water quantity to: (1) maintain underground aquifer 
function, spring flow pressure and volume, and spring water surface 
elevation, (2) allow the fish to complete its life cycle (spawning, 
rearing, feeding, etc.), and (3) allow for movement between integral 
parts of its habitat and to reduce the overlap with niches of other 
native fishes;
--sufficient vegetation in spring and surrounding marsh riparian areas 
to provide cover, food, spawning sites, prevent erosion, and to meet 
other life history requirements of the fish; and
--a biological environment in which there is little or no interaction 
with nonnative fishes.

    The Service recognizes that those habitats proposed as critical are 
not sufficient to achieve recovery for the species because they do not 
represent the historic range or all of the widely diverse habitat types 
that the species historically evolved in and occupied. The UDWR and BLM 
are currently surveying least chub habitats throughout its historic 
range to determine if the requisites necessary for recovery are still 
available. The Service, in the process of developing a ``Least Chub 
Recovery Plan,'' may utilize these new data to identify additional 
critical habitat areas needed to ensure the recovery of the species. 
The Service may, at a future date, repropose critical habitat for the 
least chub.
    Section 4(b)(8) of the Act requires, for any proposed or final 
regulation that designates critical habitat, a brief description and 
evaluation of those activities that may adversely modify or destroy 
such habitat or those activities that may be affected by such 
designation. Activities, such as habitat alterations through livestock 
impacts, pollution, or dewatering, would be detrimental to the survival 
of this species. Additionally, activities that provide for increased 
access to remote spring sites or that alter ground water or deep 
aquifer spring sources and flow rates would also be considered 
detrimental. Predation and competition from nonnative species on least 
chubs 

[[Page 50523]]
are considered major factors causing its demise. Future activities on 
Federal lands or activities requiring Federal permits in the Snake 
Valley area would have to be taken under consultation to prevent 
further adverse impacts on the least chub or its habitat.
    Impacts generally will be restricted to activities on Federal lands 
or on lands where proposed actions require Federal permits. The 
greatest impact would be on livestock grazing and its restriction in 
and around least chub habitat. Grazing would be limited within the 
general area occupied by least chub to prevent any further habitat 
degradation within proposed critical habitat. Drilling for water within 
proposed critical habitat would also be restricted. Presently, water 
regeneration within the Gandy Salt Marsh is adequate to allow for 
surface water use by livestock without impacting water levels within 
the marsh. Livestock could graze in pastures surrounding the proposed 
critical habitat areas if their access to aquatic habitats are 
prevented. Oil and gas exploration and production activities would be 
restricted within critical habitat. Surface activities and directional 
drilling are already restricted on BLM-owned lands that are designated 
as ``Category 4'' lands (these lands are already closed to leasing).
    Presently, the recharging of ground water is sufficient to offset 
current withdrawals. Any federally funded or permitted water 
withdrawals (i.e., the Las Vegas Valley Water District permits for well 
drilling) would require section 7 consultation if it is shown that 
ground water withdrawals would impact critical habitat areas.
    Section 4(b)(2) of the Act requires the Service to consider 
economic impacts of designating a particular area as critical habitat. 
The Service will prepare an economic analysis of the impacts of 
designating critical habitat for the least chub. Upon completion of the 
analysis, the Service will notify the public of its availability and 
will request public review and comments.

Available Conservation Measures

    Conservation measures provided to species listed as endangered 
under the Endangered Species Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against take. 
Recognition through listing encourages conservation actions by Federal 
and State agencies and private individuals. The Act provides for 
possible land acquisition and cooperation with the States and requires 
that recovery actions be carried out for all listed species. The 
protection required of Federal agencies and the prohibitions against 
taking and harm are discussed, in part, below.
    Section 7(a) of the Act, as amended, requires Federal agencies to 
evaluate their actions with respect to any species that is proposed or 
listed as endangered or threatened and with respect to its critical 
habitat, if designated. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR Part 402. 
Section 7(a)(4) requires Federal agencies to confer with the Service on 
any action that is likely to jeopardize the continued existence of a 
species proposed for listing or that would result in destruction or 
adverse modification of proposed critical habitat. If the least chub is 
listed, section 7(a)(2) of the Act will require Federal agencies to 
insure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of this species or to 
destroy or adversely modify its critical habitat. If a Federal action 
could possibly affect the least chub or its critical habitat, the 
responsible Federal agency must enter into formal consultation with the 
Service.
    Some portions of the least chub's proposed critical habitat are on 
private lands. The Federal Government has certain authority which may 
influence private undertakings in least chub critical habitat. Private 
activities that involve dredging and filling of wetlands would require 
a 404 permit (Federal Clean Water Act).
    It is the policy of the Service to identify, to the extent known at 
the time a species is listed, specified activities that will not be 
considered likely to result in violation of section 9 of the Act. To 
the extent possible, activities that will be in violation also will be 
identified in as specific a manner as possible. The Service believes 
that the actions listed below might potentially result in a violation 
of section 9; however, possible violations are not limited to these 
actions alone:
    (1) Unauthorized collecting or handling of the species;
    (2) Destruction or alteration of the species habitat (i.e., water 
depletions that significantly modify spring functions; activities that 
change water quality or quantity; dredging or other physical 
modifications that impact the springs; introduction of nonnative 
species);
    (3) Improper use of herbicides, fertilizers, or pesticides;
    (4) Contamination of soil or ground water by spills, discharges or 
dumping of chemicals, silt, or other pollutants associated with 
agriculture and oil and gas activities;
    Questions regarding whether a specific activity will constitute a 
violation of section 9 should be directed to the Field Supervisor of 
the Service's Salt Lake City Field office (see ADDRESSES section). 
Requests for copies of regulations concerning listed animals and 
general inquiries regarding prohibitions and permits may be addressed 
to the Fish and Wildlife Service, Ecological Services, P.O. Box 25486, 
Denver Federal Center, Denver, Colorado, (telephone 303/236-7398; 
facsimile 303/236/0027).
    The Act and implementing regulations found at 50 CFR 17.21 set 
forth a series of general prohibitions and exceptions that apply to all 
endangered wildlife. These prohibitions, codified at 50 CFR 17.21, in 
part, make it illegal for any person subject to the jurisdiction of the 
United States to take (includes harass, harm, pursue, hunt, shoot, 
wound, kill, trap, or collect; or to attempt any of these), import or 
export, ship in interstate commerce in the course of commercial 
activity, or sell or offer for sale in interstate or foreign commerce 
any listed species. It also is illegal to possess, sell, deliver, 
carry, transport, or ship any such wildlife that has been taken 
illegally. Certain exceptions apply to agents of the Service and State 
conservation agencies.
    Permits may be issued to carry out otherwise prohibited activities 
involving endangered wildlife species under certain circumstances. 
Regulations governing permits are found at 50 CFR 17.22 and 17.23. Such 
permits are available for scientific purposes, to enhance the 
propagation or survival of the species, and/or for incidental take in 
connection with otherwise lawful activities. Requests for copies of the 
regulations on animals and inquiries regarding them may be addressed to 
the Regional Director, U.S. Fish and Wildlife Service, P.O. Box 25486, 
Denver Federal Center, Denver, Colorado 80225 (telephone 303/236-7398).

Public Comments Solicited

    The Service intends that any final action resulting from this 
proposal will be as accurate and as effective as possible. Therefore, 
any comments or suggestions concerning biological information and 
potential threats to the least chub are requested from the public, 
other concerned governmental agencies, the scientific community, 
industry, or any other interested party. Comments are sought 
particularly concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any 

[[Page 50524]]
threat (or the lack thereof) to the least chub;
    (2) The location of any additional populations of least chub and 
the reasons why any habitat should or should not be determined to be 
critical habitat as provided by section 4 of the Act;
    (3) Additional information concerning the range, distribution, and 
population size of this species;
    (4) Current or planned activities which may adversely modify the 
area which is being considered for critical habitat; and
    (5) Any foreseeable economic and other impacts resulting from the 
proposed designation of critical habitat.
    (6) Final promulgation of this regulation on the least chub will 
take into consideration the comments and any additional information 
received by the Service, and such communications may lead to a final 
regulation that differs from this proposal.
    The Endangered Species Act provides for a public hearing on this 
proposal, if requested. Requests must be received within 45 days of the 
date of publication of the proposal. Such requests must be made in 
writing to the Field Supervisor (see ADDRESSES section).

National Environmental Policy Act

    The Service has determined that Environmental Assessments and 
Environmental Impact Statements, as defined under the authority of the 
National Environmental Policy Act of 1969, need not be prepared in 
connection with regulations adopted pursuant to section 4(a) of the 
Endangered Species Act of 1973, as amended. A notice outlining the 
Service's reasons for this determination was published in the Federal 
Register on October 25, 1983 (48 FR 49244).

References Cited

    A complete list of all references cited herein is available upon 
request from the Field Supervisor (see ADDRESSES section).

Authors

    The primary author of this proposed rule is Doug Young (see 
ADDRESSES section).

List of Subjects in 59 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, and Transportation.

Proposed Regulation Promulgation

    Accordingly, it is hereby proposed to amend part 17, subchapter B 
of chapter I, title 50 of the Code of Federal Regulations, as set forth 
below:

PART 17--[AMENDED]

    1. The authority citation for Part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.

    2. It is proposed to amend Sec. 17.11(h) is amended by adding the 
following, in alphabetical order under fishes, to the List of 
Endangered and Threatened Wildlife to read as follows:


Sec. 17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                      SPECIES                                                    Vertebrate population                                                  
----------------------------------------------------      Historic range          where endangered or      Status    When listed    Critical    Special 
       Common name              Scientific name                                       threatened                                    habitat      rules  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fishes...................                                                                                                                               
                                                                                                                                                        
          *                  *                  *                  *                  *                  *                  *                           
Chub, least..............  Iotichthys phlegethontis  U.S.A. (UT).............  Entire..................  E           ...........     17.95(e)         NA
                                                                                                                                                        
          *                  *                  *                  *                  *                  *                  *                           
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. It is further proposed to amend Sec. 17.95(e) by adding critical 
habitat for the least chub, in the same alphabetical order as the 
species occurs in 17.11(h) to read as follows:


Sec. 17.95  Critical habitat--fish and wildlife.

* * * * *
    (e) * * *
* * * * *
LEAST CHUB (Iotichthys phlegethontis)
    1. Northern Snake Valley Group, Utah: Tooele and Juab Counties, 
Snake Valley. The following areas including all springs, outflow pools, 
runoffs streams, marshes, and a \1/8\-mile zone on all sides of 
springs, pools, streams, and marshes:
    T9S, R16W, SW\1/4\ Sec. 31; T9S, R17W, SE\1/4\ of SE\1/4\ Sec. 36; 
T10S, R17W, E\1/2\, of NE\1/4\ Sec. 1, SW\1/4\ Sec. 25, W\1/2\ of SE\1/
4\ Sec. 25, S\1/2\ of NW\1/4\ Sec. 25, E\1/2\ of SE\1/4\ Sec. 26, E\1/
2\ of E\1/2\ Sec. 35, W\1/2\ Sec. 36,W\1/2\ of E\1/2\ Sec. 36; T10S, 
R16W, NW\1/4\ Sec. 6; T11S, R17W, NW\1/2\ Sec. 1, W\1/2\ of NE\1/4\ 
Sec. 1.

    Note: Map follows:

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[[Page 50526]]

    2. Southern Snake Valley Group, Utah, Juab and Millard Counties, 
Snake Valley. The following areas including all springs, outflow pools, 
runoff streams, marshes, and a \1/8\-mile zone on all sides of springs, 
pools, streams, and marshes, excluding Foote Reservoir, but including 
the spring source for Foote Reservoir:
    T14S, R18W, SW\1/4\ of NE\1/4\ Sec. 22, SE\1/4\ of NW\1/4\ Sec. 22, 
NW\1/4\ of NW\1/4\ Sec. 22, N\1/2\ of SW\1/4\ Sec. 22, SE\1/4\ of SE\1/
4\ Sec. 21. W\1/2\ of NE\1/4\ Sec. 28, SE\1/4\ of NW\1/4\ Sec. 28, 
SW\1/4\ Sec. 28, SE\1/4\ of SE\1/4\ Sec. 29, NW\1/4\ Sec. 33, NW\1/4\ 
of SW\1/4\ Sec. 33, E\1/2\ Sec. 32; T15S, R18W, E\1/2\ Sec. 5, E\1/2\ 
Sec. 8, NW\1/4\ of NE\1/4\ Sec. 17, SE\1/4\ of NW\1/4\ Sec. 17, NE\1/4\ 
Sec. 17, NW\1/4\ of SE\1/4\ Sec. 17, SE\1/4\ of SE\1/4\ Sec. 18, NW\1/
4\ of NW\1/4\ Sec. 20, NE\1/4\ Sec. 19, SE\1/4\ of NW\1/4\ Sec. 19, 
E\1/2\ of SW\1/4\ Sec. 19 W\1/2\ of SE\1/2\ Sec. 19, W\1/2\ of NE\1/4\ 
Sec. 30, W\1/2\ Sec. 30, W\1/2\ of NW\1/4\ Sec. 31, SW\1/4\ Sec. 31, 
SW\1/4\ of SE\1/4\ Sec. 31; T15S, R19W, SE\1/4\ of SE\1/4\ Sec. 25, 
E\1/2\ of SE\1/4\ Sec. 25, E\1/2\ of NE\1/4\ Sec. 36, E\1/2\ of SE\1/4\ 
Sec. 36; T16S, R18W, E\1/2\ Sec. 6, N\1/2\ of NW\1/4\ Sec. 6, E\1/2\ 
Sec. 7, W\1/2\ of W\1/2\ Sec. 8, NE\1/4\ of NE\1/4\ Sec. 18, NW\1/4\ 
Sec. 17, SW\1/4\ of NE\1/4\ Sec. 17, NE\1/4\ of SW\1/4\ Sec. 17, SE\1/
4\ Sec. 17, S\1/2\ of S\1/2\ Sec. 16, SW\1/2\ of SW\1/4\ Sec. 15, E\1/
2\ of NE\1/4\ Sec. 20, NE\1/4\ of SE\1/4\ Sec. 20, N\1/2\ Sec. 21, N\1/
2\ of SW\1/4\ Sec. 21, SE\1/4\ Sec. 21, S\1/2\ of NW\1/4\ Sec. 22, 
SW\1/4\ of NE\1/4\ Sec. 22, N\1/2\ of SW\1/4\ Sec. 22, SW\1/4\ of SW\1/
4\ Sec. 22, NW\1/4\ of SE\1/4\ Sec. 22, E\1/2\ of NE\1/4\ Sec. 28, W\1/
2\ of NW\1/4\ Sec. 27.

    Note. Map follows:

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[[Page 50528]]

    3. Tule Valley Group, Utah: Millard County, Tule Valley. The 
following areas including all springs, outflow pools, runoff streams, 
marshes, and a \1/8\-mile zone on all sides of springs, pools, streams, 
and marshes:
    T16S, R15W, SE\1/4\ of SW\1/4\ Sec. 12, SW\1/2\ of SE\1/4\ Sec. 12, 
E\1/2\ of NW\1/4\ Sec. 13, W\1/2\ of NE\1/4\ Sec. 13, S\1/2\ of SE\1/4\ 
Sec 34; T17S, R15W, E\1/2\ Sec. 3, W\1/4\ of SW\1/2\ Sec. 2, N\1/2\ of 
NE\1/4\ Sec. 10, SW\1/4\ of NE\1/4\ Sec. 10, W\1/2\ of SE\1/4\ Sec. 10, 
W\1/2\ of NE\1/4\ Sec. 15, E\1/2\ of NW\1/4\ Sec. 15.

    Note. Map follows:
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[[Page 50529]]
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[[Page 50530]]

    Constituent elements for all areas of critical habitat include 
permanent sources of water, water quality and quantity to satisfy 
requirements for all life history stages of the fish, a predator-free 
habitat, adequate vegetative cover, and other environmental features 
that may be deemed necessary upon site-specific evaluations.

    Dated: September 18, 1995.
George T. Frampton,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 24320 Filed 9-28-95; 8:45 am]
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