[Federal Register Volume 74, Number 128 (Tuesday, July 7, 2009)]
[Proposed Rules]
[Pages 32352-32387]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-15828]



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Part V





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; 12-Month Finding on a 
Petition To List a Distinct Population Segment of the Roundtail Chub 
(Gila robusta) in the Lower Colorado River Basin; Proposed Rule

  Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / 
Proposed Rules  

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWS-R2-ES-2009-0004; MO 92210530083-B2]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List a Distinct Population Segment of the Roundtail 
Chub (Gila robusta) in the Lower Colorado River Basin

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list a distinct population segment 
(DPS) of the roundtail chub (Gila robusta) in the lower Colorado River 
basin as endangered or threatened under the Endangered Species Act of 
1973, as amended (Act). The petition also asked the Service to 
designate critical habitat. After review of all available scientific 
and commercial information, we find that the petitioned listing action 
is warranted, but precluded by higher priority actions to amend the 
Lists of Endangered and Threatened Wildlife and Plants. Upon 
publication of this 12-month petition finding, this species will be 
added to our candidate species list. We will develop a proposed rule to 
list this population segment of the roundtail chub pursuant to our 
Listing Priority System. Any determinations on critical habitat will be 
made at that time.

DATES: The finding announced in this document was made on July 7, 2009.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R2-ES-2009-0004. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, Arizona Ecological Services Office, 2321 
West Royal Palm Road, Suite 103, Phoenix, AZ 85021-4951. Please submit 
any new information, materials, comments, or questions concerning this 
finding to the above address.

FOR FURTHER INFORMATION CONTACT: Steve Spangle, Field Supervisor, 
Arizona Ecological Services Office (see ADDRESSES), telephone 602-242-
0210. If you use a telecommunications device for the deaf (TDD), please 
call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires 
that, for any petition to revise the Lists of Endangered and Threatened 
Wildlife and Plants that contains substantial scientific or commercial 
information that the action may be warranted, we make a finding within 
12 months of the date of the receipt of the petition on whether the 
petitioned action is: (a) Not warranted, (b) warranted, or (c) 
warranted but the immediate proposal of a regulation implementing the 
petitioned action is precluded by other pending proposals to determine 
whether species are threatened or endangered, and expeditious progress 
is being made to add or remove qualified species from the Lists of 
Endangered and Threatened Wildlife and Plants. Section 4(b)(3)(C) of 
the Act requires that we treat a petition for which the requested 
action is found to be warranted but precluded as though resubmitted on 
the date of such finding, that is, requiring a subsequent finding to be 
made within 12 months. We must publish these 12-month findings in the 
Federal Register.

Previous Federal Actions

    In 1985, the roundtail chub (Gila robusta) was placed on the list 
of candidate species as a category 2 species (50 FR 37958). Category 2 
species were those for which existing information indicated that 
listing was possibly appropriate, but for which substantial supporting 
biological data were lacking. Due to lack of funding to gather existing 
information on the roundtail chub, the species remained in category 2 
through the 1989 (54 FR 554), 1991 (56 FR 58804) and 1994 (59 FR 58982) 
candidate notices of review. In the 1996 candidate notice of review (61 
FR 7596), category 2 was eliminated, and roundtail chub no longer had 
formal status under the candidate identification system.
    On April 14, 2003, we received a petition from the Center for 
Biological Diversity requesting that we list a DPS of the roundtail 
chub (Gila robusta) in the lower Colorado River basin (defined as all 
waters tributary to the Colorado River in Arizona and the portion of 
New Mexico in the Gila River and Zuni River basins) as endangered or 
threatened, that we list the headwater chub (Gila nigra) as endangered 
or threatened, and that we designate critical habitat concurrently with 
the listing for both species.
    Following receipt of the 2003 petition, and pursuant to a 
stipulated settlement agreement, on July 12, 2005, we published our 90-
day finding that the petition presented substantial scientific 
information indicating that listing the headwater chub and a DPS of the 
roundtail chub in the lower Colorado River basin may be warranted, and 
we initiated 12-month status reviews for these species (70 FR 39981).
    On May 3, 2006, we published our 12-month finding that listing was 
warranted for the headwater chub, but precluded by higher priority 
listing actions, and that listing of a population segment of the 
roundtail chub in the lower Colorado River basin was not warranted 
because it did not meet our definition of a DPS (71 FR 26007).
    On September 7, 2006, we received a complaint from the Center for 
Biological Diversity for declaratory and injunctive relief, challenging 
our decision not to list the lower Colorado River basin population of 
the roundtail chub as an endangered species under the Act. On November 
5, 2007, in a stipulated settlement agreement, we agreed to commence a 
new status review of the lower Colorado River basin population segment 
of the roundtail chub and to submit a 12-month finding to the Federal 
Register by June 30, 2009. On March 3, 2009, we published a notice in 
the Federal Register that we were initiating a status review and 
soliciting new information for reevaluating the 2003 petition to list a 
lower Colorado River basin DPS of the roundtail chub (74 FR 9205).

Defining a Species Under the Act

    Section 3(16) of the Act defines ``species'' to include ``any 
subspecies of fish or wildlife or plants, and any distinct population 
segment of any species of vertebrate fish or wildlife which interbreeds 
when mature'' (16 U.S.C. 1532(16)). Our implementing regulations at 50 
CFR 424.02 provide further guidance for determining whether a 
particular taxon or population is a species or subspecies for the 
purposes of the Act: ``[T]he Secretary shall rely on standard taxonomic 
distinctions and the biological expertise of the Department and the 
scientific community concerning the relevant taxonomic group'' (50 CFR 
424.11(a)). As previously discussed, the population segment of 
roundtail chub in the lower Colorado River basin is classified as Gila 
robusta, the same as other roundtail chub populations, and as such we 
do not consider the population segment of roundtail chub in the lower 
Colorado River basin to constitute a distinct species or subspecies. 
Since the population segment of roundtail chub in the lower Colorado 
River basin is not a

[[Page 32353]]

distinct species or subspecies, we then evaluated whether it is a 
distinct population segment to determine whether it would constitute a 
listable entity under the Act.
    To interpret and implement the DPS provisions of the Act and 
Congressional guidance, the Service and the National Marine Fisheries 
Service (now the National Oceanic and Atmospheric Administration--
Fisheries), published the Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act (DPS 
Policy) in the Federal Register on February 7, 1996 (61 FR 4722). Under 
the DPS Policy, three elements are considered in the decision regarding 
the establishment and classification of a population of a vertebrate 
species as a possible DPS. These are applied similarly for additions to 
and removals from the Lists of Endangered and Threatened Species. These 
elements are (1) the discreteness of a population in relation to the 
remainder of the species to which it belongs, (2) the significance of 
the population segment to the species to which it belongs, and (3) the 
population segment's conservation status in relation to the Act's 
standards for listing, delisting, or reclassification (i.e., is the 
population segment endangered or threatened?).

Distinct Vertebrate Population Segment Analysis

    In the 2003 petition, we were asked to consider listing a DPS for 
the roundtail chub in the lower Colorado River basin (the Colorado 
River and its tributaries downstream of Glen Canyon Dam including the 
Gila and Zuni River basins in New Mexico). Per our November 5, 2007, 
stipulated settlement agreement, we are reevaluating our May 3, 2006, 
determination (71 FR 26007) that listing the roundtail chub population 
segment in the lower Colorado River basin was not warranted because it 
did not meet our definition of a DPS.
    In accordance with our DPS Policy, this section details our 
analysis of the first two elements we consider in a decision regarding 
the status of a possible DPS as endangered or threatened under the Act. 
These elements are (1) the population segment's discreteness from the 
remainder of the species to which it belongs and (2) the significance 
of the population segment to the species to which it belongs.

Discreteness

    The DPS policy's standard for discreteness requires an entity to be 
adequately defined and described in some way that distinguishes it from 
other representatives of its species. A population segment of a 
vertebrate species may be considered discrete if it satisfies either 
one of the following two conditions: (1) It is markedly separated from 
other populations of the same taxon as a consequence of physical, 
physiological, ecological, or behavioral factors (quantitative measures 
of genetic or morphological discontinuity may provide evidence of this 
separation); or (2) it is delimited by international governmental 
boundaries within which significant differences in control of 
exploitation, management of habitat, conservation status, or regulatory 
mechanisms exist.
    The historical range of roundtail chub included both the upper and 
lower Colorado River basins in the States of Wyoming, Utah, Colorado, 
New Mexico, Arizona, and Nevada (Propst 1999, p. 23; Bezzerides and 
Bestgen 2002, p. 25; Voeltz 2002, pp. 19-23), but the roundtail chub 
was likely only a transient in Nevada. Currently roundtail chubs occur 
in both the upper and lower Colorado River basins in Wyoming, Utah, 
Colorado, New Mexico, and Arizona. Bezzerides and Bestgen (2002, p. 24) 
concluded that historically there were two discrete population centers, 
one in each of the lower and upper basins, and that these two 
population centers remain today. Numerous authors have noted that 
roundtail chub was very rare with few documented records in the 
mainstem Colorado River between the two basins (Minckley 1973, p. 102; 
Minckley 1979, p. 51; Valdez and Ryel 1994, pp. 5-10-5-11; Minckley 
1996, p. 75; Bezzerides and Bestgen 2002, pp. 24-25; Voeltz 2002, pp. 
19, 112), so we do not consider the mainstem to have been occupied 
historically, and have not considered the Colorado River in our 
estimates of historical range. Early surveyors also variably used the 
term ``bonytail'' to describe roundtail chub (Valdez and Ryel 1994, pp. 
5-7), further clouding information on historical distribution, as some 
accounts of roundtail chub in the mainstem may have been bonytail (Gila 
elegans), which is a mainstem species in the Colorado River. Records 
from the mainstem Colorado River also may have been transients from 
nearby populations, such as some records from Grand Canyon, which may 
have been from the Little Colorado River (Voeltz 2002, p. 112). One 
record from between the two basins, a record of two roundtail chubs 
captured near Imperial Dam in 1973, illustrates this. Upon examining 
these specimens, Minckley (1979, p. 51) concluded that they were strays 
washed downstream from the Bill Williams River based on their heavily 
blotched coloration. This is a logical conclusion considering that 
roundtail chub from the Bill Williams River typically exhibit this 
blotched coloration (Rinne 1969, pp. 20-21; Rinne 1976, p. 78). 
Minckley (1979, p. 51), Minckley (1996, p. 75), and Mueller and Marsh 
(2002, p. 40) also considered roundtail chub rare or essentially absent 
in the Colorado River mainstem based on the paucity of records from 
numerous surveys of the Colorado River mainstem.
    We conclude that historically, roundtail chub occurred in the 
Colorado River basin in two population centers, one each in the upper 
(largely in Utah and Colorado, and to a lesser extent, in Wyoming and 
New Mexico) and lower basins (Arizona and New Mexico), with apparently 
little, if any, mixing of the two populations. If there was one 
population, we would expect to find a large number of records in the 
mainstem Colorado River between the San Juan and Bill Williams Rivers, 
but very few records of roundtail chub exist from this reach of stream. 
Also, there is a substantial distance between these areas of roundtail 
chub occurrence in the two basins. The mouth of the Escalante River, 
which contains the southernmost population of roundtail chub in the 
upper basin, is approximately 275 river miles (mi) (443 kilometers 
(km)) upstream from Grand Falls on the Little Colorado River, the 
historical downstream limit of the most northern population of the 
lower Colorado River basin. The lower Colorado River basin roundtail 
chub population segment meets the element of discreteness because it 
was separate historically, and continues to be markedly separate today.
    In more recent times, the upper and lower basin populations of the 
roundtail chub have been physically separated by Glen Canyon Dam, but 
that artificial separation is not the sole basis for our finding that 
the lower basin population is discrete from the upper basin. The 
historical information on collections suggests that there was limited 
contact even before the dam was built. Available molecular information 
for the species, although sparse, seems to support this; mitochondrial 
DNA markers (mtDNA; a type of genetic material) of roundtail chub in 
the Gila River basin are entirely absent from upper basin populations 
(Gerber et al. 2001, p. 2028; see Significance discussion below).

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Significance

    If we have determined that a vertebrate population segment is 
discrete under our DPS policy, we consider its biological and 
ecological significance to the taxon to which it belongs in light of 
Congressional guidance (see Senate Report 151, 96th Congress, 1st 
Session) that the authority to list DPSs be used ``sparingly'' while 
encouraging the conservation of genetic diversity. To evaluate whether 
a discrete vertebrate population may be significant to the taxon to 
which it belongs, we consider available scientific evidence of the 
discrete population segment's importance to the taxon to which it 
belongs. Since precise circumstances are likely to vary considerably 
from case to case, the DPS policy does not describe all the classes of 
information that might be used in determining the biological and 
ecological importance of a discrete population. However, the DPS policy 
describes four possible classes of information that provide evidence of 
a population segment's biological and ecological importance to the 
taxon to which it belongs. This consideration may include, but is not 
limited to: (1) Persistence of the discrete population segment in an 
ecological setting that is unusual or unique for the taxon; (2) 
evidence that loss of the discrete population segment would result in a 
significant gap in the range of the taxon; (3) evidence that the 
discrete population segment represents the only surviving natural 
occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historical range; or (4) evidence 
that the discrete population segment differs markedly from other 
populations of the species in its genetic characteristics.
    Ecological Setting. Based on our review of the available 
information, we found that there are some differences in various 
ecoregion variables between the upper and lower Colorado River basins. 
For example, McNabb and Avers (1994) and Bailey (1995) delineated 
ecoregions and sections of the United States based on a combination of 
climate, vegetation, geology, and other factors. Populations of 
roundtail chub in the lower basin are primarily found in the Tonto 
Transition and Painted Desert Sections of the Colorado Plateau Semi-
Desert Province in the Dry Domain, and the White Mountain-San Francisco 
Peaks-Mogollon Rim Section of the Arizona-New Mexico Mountains Semi-
Desert-Open Woodland-Coniferous Forest Province Dry Domain. Populations 
of roundtail chub in the upper basin are primarily found in the 
Northern Canyonlands and Uinta Basin Sections of the Intermountain 
Semi-Desert and Desert Province in the Dry Domain, and the Tavaputs 
Plateau and Utah High Plateaus and Mountains Sections of the Nevada-
Utah Mountains Semi-Desert-Coniferous Forest Province in the Dry Domain 
(McNabb and Avers 1994; Bailey 1995). These ecoregions display 
differences in hydrograph, sediment, substrate, nutrient flow, cover, 
water chemistry, and other habitat variables of roundtail chub. Also, 
there are differences in type, timing, and amount of precipitation 
between the two basins, with the upper basin (3-65 inches (in) per year 
(8-165 centimeters (cm) per year)) (Jeppson 1968, p. 1) somewhat less 
arid than the lower basin (5-25 in per year (13-64 cm per year)) (Green 
and Sellers 1964, pp. 8-11).
    The type (snow or rain) and timing of precipitation are major 
factors determining the pattern of annual streamflow. A hydrograph 
depicts the amount of runoff or discharge over time (Leopold 1997, pp. 
49-50). The hydrograph of a stream is a major factor in determining 
habitat characteristics and their variability over space and time. 
Habitats of roundtail chub in the lower basin have a monsoon hydrograph 
or a mixed monsoon-snowmelt hydrograph. A monsoon hydrograph results 
from distinctly bimodal annual precipitation, which creates large, 
abrupt, and highly variable flow events in late summer and large, 
longer, and less variable flow events in the winter (Burkham 1970, pp. 
B3-B7; Green and Sellers 1964, pp. 8-11; Minckley and Rinne 1991, 
p.12). Monsoon hydrographs are characterized by high variability, 
including rapid rise and fall of flow levels with flood peaks of one or 
more orders of magnitude greater than base, or ``normal low'' flow 
(Burkham 1970, pp. B3-B7; Ray et al. 2007, p. 1617).
    In the upper basin, roundtail chub habitats have strong snowmelt 
hydrographs, with some summer, fall, and winter precipitation, but with 
the majority of major flow events in spring and early summer (Bailey 
1995, p. 341; Carlson and Muth 1989, p. 222; Woodhouse et al. 2003, p. 
1551). Snowmelt hydrographs are characterized by low variability; long, 
slow rises and falls in flow; and peak flow events that are less than 
an order of magnitude greater than the base flow.
    The lower basin has lower stream flows and warmer temperatures in 
late spring and early summer; in contrast, this is typically the 
wettest period in the upper basin (Carlson and Muth 1989, p. 222). 
Regarding the differences between the two basins, Carlson and Muth 
(1989), for example, conclude, ``The upper basin produced most of the 
river's discharge, and peak flows occurred after snowmelt in spring and 
early summer. Maximum runoff in the lower basin often followed winter 
rainstorms.'' Sediment loads vary substantially between streams in both 
basins, but are generally lesser in the upper basin than the lower, and 
patterning of sediment movement differs substantially because of the 
different hydrographs. In general, roundtail chub habitat in the lower 
Colorado River basin is of lower gradient, smaller average substrate 
size, higher water temperatures, higher salinity, smaller base flows, 
higher flood peaks, lesser channel stability and higher erosion, and 
substantially different hydrographs than the habitat in the upper 
Colorado River basin. Measurable hydrographic differences between the 
two basins are evident, as are differences in landscape-level roundtail 
chub habitats between the upper and lower basins.
    Gap in the Range. Roundtail chub in the lower Colorado River basin 
can be considered significant under our DPS analysis because loss of 
the lower Colorado River populations of roundtail chub would result in 
a significant gap in the range of the taxon; this area constitutes over 
one third of the species' historical range (2 out of 6 States), 
including the species' entire current range in two States (Arizona and 
New Mexico) and all of several major river systems, including the 
Little Colorado, Bill Williams, and Gila River basins. Additionally 
there are 74 populations of roundtail chub remaining in the upper basin 
and 31 in the lower basin; thus, the lower basin populations also 
constitute approximately one third (30 percent) of the remaining 
populations of the species (Bezzerides and Bestgen 2002, pp. 28-29, 
Appendix C; Voeltz 2002, pp. 82-83). The populations in the lower basin 
also account for approximately 107,300 square mi (270,906 square km; 49 
percent) of the 219,310 square mi (568,010 square km) of the Colorado 
River Basin (U.S. Geological Survey 2006, pp. 94-102). In addition, the 
roundtail chub historically occupied up to 2,796 mi (4,500 km) of 
stream in the lower basin and currently occupies between 497 mi (800 
km) and 901 mi (1450 km) of stream habitat in the lower basin. These 
populations are not newly established, ephemeral, or migratory; the 
species has been well established in the lower Colorado River basin, 
and has represented a large portion of the species' range for a long 
period of time (Bezzerides and Bestgen 2002, pp. 20-29; Voeltz 2002, 
pp. 82-83).

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    Whether the Population Represents the Only Surviving Natural 
Occurrence of the Taxon. As part of a determination of significance, 
our DPS policy suggests that we consider whether there is evidence that 
the population represents the only surviving natural occurrence of a 
taxon that may be more abundant elsewhere as an introduced population 
outside its historical range. The roundtail chub in the lower Colorado 
River basin is not the only surviving natural occurrence of the 
species. Consequently, this factor is not applicable to our 
determination regarding significance.
    Marked Differences in Genetic Characteristics. Long-standing 
difficulties in morphological discrimination and taxonomic distinction 
among members from the lower Colorado G. robusta complex, and the genus 
Gila as a whole, due in part to the role hybridization has played in 
its evolution, have plagued conservation efforts. But it is important 
to consider variation throughout the entire Colorado River basin to 
place variation and divergence in the lower basin Gila robusta complex 
in appropriate context. Two isolated species of hybrid origin 
(involving G. robusta with G. elegans and G. cypha) can be found in the 
Virgin and White River drainages (G. seminuda--DeMarais et al. 1992, p. 
2747; G. jordani--Gerber et al. 2001, p. 2033, respectively). Gila 
robusta is relatively abundant in the mainstem Colorado River and 
tributaries above the Glen Canyon Dam in the upper basin. All 
individuals from the headwaters of the Little Colorado River and the 
mainstem Colorado River and tributaries above Glen Canyon Dam in the 
upper basin possess G. cypha or G. elegans mtDNA (Dowling and DeMarais 
1993, pp. 444-446; Gerber et al. 2001, p. 2028). However, populations 
of the G. robusta complex of the lower basin in the Bill Williams and 
Gila River basins (including G. robusta, G. intermedia, and G. nigra) 
possess a unique, divergent mtDNA lineage that has never been found 
outside the lower basin (Dowling and DeMarais 1993, pp. 444-446; Gerber 
et al. 2001, p. 2028). But as Gerber et al. (2001, p. 2037) noted, 
genetic information in Gila poorly accounts for species morphology, 
stating ``the decoupling of morphological and mtDNA variation in 
Colorado River Gila illustrates how hybridization and local adaptation 
can play important roles in evolution.'' Although individuals in the 
Little Colorado River illustrate some minor genetic uniqueness, the 
evidence, though limited (samples size in Gerber et al. 2001 was 
limited to 7 individuals) indicates these populations align more 
closely with the upper Colorado River basin populations. But 
discriminating between populations of Gila based on these data is 
difficult, and more data and analysis may help to place these 
populations in better perspective.

DPS Conclusion

    We have reevaluated the lower Colorado River populations of the 
roundtail chub to determine whether they meet the definition of a DPS, 
addressing discreteness and significance as required by our policy. We 
have considered the extent of the range of the roundtail chub in the 
lower Colorado River basin relative to the rest of the species' range, 
the ecological setting of roundtail chub in the lower Colorado River 
basin, and available information on the genetics of the species. We 
conclude that the lower Colorado River populations are discrete from 
the upper Colorado River basin populations on the basis of their 
present and historical geographic separation of 275 river mi (444 km) 
and because few historical records have been detected in the mainstem 
Colorado River between the two population centers that would confirm 
significant connectivity historically. We also conclude that the lower 
Colorado River basin roundtail chub is significant because of its 
unique ecological setting compared to the upper basin, and because the 
loss of the species from the lower basin would result in a significant 
gap in the range of the species. Genetic information for this species 
has long been difficult to interpret, and additional data and analysis 
may help to clarify this.
    In our 2006 finding, we made the determination that the roundtail 
chub in the lower Colorado River basin did not meet our definition of a 
DPS. We have reevaluated that determination and now find the best 
available information has demonstrated that these populations are 
discrete, persist in an ecological setting that is unique for the 
taxon, and, if lost, would result in a significant gap in the range of 
the taxon. Because this population segment meets both the discreteness 
and significance elements of our DPS policy, the lower Colorado River 
population segment of the roundtail chub qualifies as a DPS in 
accordance with our DPS policy, and as such, is a listable entity under 
the Act. Below we provide a summary of the biology, status, and 
distribution of the DPS, and an analysis of threats to the DPS, based 
on the five listing factors established by the Act.

Biology

    The roundtail chub is a cyprinid fish (member of Cyprinidae, the 
minnow family) with a streamlined body shape. Color in roundtail chub 
is usually olive-gray to silvery, with the belly lighter, and sometimes 
with dark blotches on the sides. Roundtail chubs are generally 9 to 14 
in. (25 to 35 cm) in length, but can reach 20 in. (50 cm) (Minckley 
1973, pp. 101-103; Sublette et al. 1990, pp. 126-129; Propst 1999, pp. 
23-25; Minckley and Demaris 2000, pp. 251-256; Voeltz 2002, pp. 8-11). 
Baird and Girard first described roundtail chub from specimens 
collected from the Zuni River in northeastern Arizona and northwestern 
New Mexico (Baird and Girard 1853, pp. 368-369). Roundtail chub has 
been recognized as a distinct species since the 1800s (Miller 1945, p. 
104; Holden 1968, pp. 27-28; Rinne 1969, pp. 27-42; Holden and 
Stalnaker 1970, p. 409; Rinne 1976, pp. 87-91; Smith et al. 1979, p. 
623; DeMarais 1986, p. iii; Douglas et al. 1989, p. 653; Rosenfeld and 
Wilkinson 1989, p. 232; DeMarais 1992, pp. 63-64; Dowling and DeMarais 
1993, p. 444; Douglas et al. 1998, p. 169; Minckley and DeMarais 2000, 
p. 255; Gerber et al. 2001, p. 2028), and is currently recognized as a 
species by the American Fisheries Society (Nelson et al. 2004, p. 71). 
The chubs of the genus Gila in the lower Colorado River basin are all 
closely related and are often regarded as a species complex (Minckley 
1973, p. 101; DeMarais 1992, p. 150; Dowling and DeMarais 1993, p. 444; 
Minckley and DeMarais 2000, p. 251; Gerber et al. 2001, p. 2028).
    Roundtail chubs in the lower Colorado River basin are found in cool 
to warm waters of rivers and streams, and often occupy the deepest 
pools and eddies of large streams (Minckley 1973, p. 101; Brouder et 
al. 2000, pp. 6-8; Minckley and DeMarais 2000, p. 255; Bezzerides and 
Bestgen 2002, pp. 17-19). Although roundtail chubs are often associated 
with various cover features, such as boulders, vegetation, and undercut 
banks, they are less apt to use cover than other related species such 
as the headwater chub and Gila chub (Gila intermedia) (Minckley and 
DeMarais 2000, p. 2145). Water temperatures of habitats occupied by 
roundtail chub vary between 0 degrees and greater than 32 degrees 
Celsius ([deg]C) (32 to 90 degrees Fahrenheit ([deg]F)) (Bestgen 1985, 
p. 14). Carveth et al. (2006, p. 1435) reported the upper thermal 
tolerance of roundtail chub to be 36.6 [deg]C (97.9 [deg]F); spawning 
has been documented from 14 to 24 [deg]C (57 to 75 [deg]F) (Bestgen 
1985, p. 14; Kaeding et al. 1990, p. 139; Brouder et

[[Page 32356]]

al. 2000, p. 13). Spawning occurs from February through June in pool, 
run, and riffle habitats, with slow to moderate water velocities (Neve 
1976, p. 32; Bestgen 1985, pp. 56-67; Propst 1999, p. 24; Brouder et 
al. 2000, p. 12; Voeltz 2002, p. 16). Roundtail chubs live for 5 to 7 
years and spawn from age 2 on (Bestgen 1985, p. 62; Brouder et al. 
2000, p. 12). Roundtail chubs are omnivores, consuming foods 
proportional to their availability, including aquatic and terrestrial 
invertebrates, aquatic plants, detritus, and fish and other 
vertebrates; algae and aquatic insects can be major portions of the 
diet (Bestgen 1985, pp. 46-53; Schreiber and Minckley 1981, pp. 409, 
415; Propst 1999, p. 24).

Status and Distribution of the Lower Colorado River DPS

    The historical distribution of roundtail chub in the lower Colorado 
River basin is poorly documented because there were few early 
collections, and perhaps more importantly, because many populations of 
native fish, including roundtail chub, were likely lost prior to early 
comprehensive fish surveys because habitat-altering actions (e.g., 
dewatering, livestock grazing, mining) were widespread, and had already 
severely altered aquatic habitats (Girmendonk and Young 1997, p. 50; 
Minckley 1999, p. 179; Voeltz, 2002, p. 19). Roundtail chub was 
historically considered common throughout its range (Minckley 1973, p. 
101; Holden and Stalnaker 1975, p. 222; Propst 1999, p. 23). Voeltz 
(2002), estimating historical distribution based on museum collection 
records, agency database searches, literature searches, and discussion 
with biologists, found that roundtail chub in the lower Colorado River 
basin was historically found in the Gila and Zuni Rivers in New Mexico; 
the Black, Colorado (though likely only as a transient), Little 
Colorado, Bill Williams, Gila, San Francisco, San Carlos, San Pedro, 
Salt, Verde, White, and Zuni Rivers in Arizona: and numerous 
tributaries within those basins. Voeltz (2002, p. 83) estimated the 
lower Colorado River basin roundtail chub historically occupied 
approximately 2,796 mi (4,500 km) of rivers and streams in Arizona and 
New Mexico. Although roundtail chubs were never collected from the 
Colorado River or San Pedro River basin in Mexico, they may have 
occurred in these areas based on records near the international border 
in the lower Colorado River and upper San Pedro River and the 
occurrence of suitable habitat in these streams in Mexico (Voeltz 2002, 
p. 20).
    Miller (1961) first comprehensively documented the decline of 
fishes of the southwestern United States in 1961, but interestingly, 
F.M. Chamberlain made similar observations in Arizona in 1904; 
roundtail chub was included in these assessments and in subsequent 
evaluations of imperiled fish species of the region (Miller 1961, pp. 
373-379; Miller 1972, p. 242; Deacon et al. 1979, p. 34; Minckley 1999, 
pp. 215-218). The decline of the species has been documented both in 
the scientific peer-reviewed literature (Bestgen and Propst 1989, p. 
402) and in State agency reports (Girmendonk and Young 1997, p. 49; 
Propst 1999, p. 23; Brouder et al. 2000, p. 1; Bezzerides and Bestgen 
2002, pp. iii-iv; Voeltz 2002, p. 83). Roundtail chub is considered 
vulnerable by the American Fisheries Society (Jenks et al. 2008, p. 
390).
    Roundtail chub in the lower Colorado River basin in Arizona 
currently occurs in two tributaries of the Little Colorado River 
(Chevelon and East Clear Creeks); several tributaries of the Bill 
Williams River basin (Boulder, Burro, Conger, Francis, Kirkland, 
Sycamore, Trout, and Wilder Creeks); the Salt River and four of its 
tributaries (Ash Creek, Black River, Cherry Creek and Salome Creek); 
the Verde River and five of its tributaries (Fossil, Oak, Roundtree 
Canyon, West Clear, and Wet Beaver Creeks); Aravaipa Creek (a tributary 
of the San Pedro River); Eagle Creek (a tributary of the Gila River); 
and in New Mexico, in the upper Gila River (Voeltz 2002, pp. 82-83; the 
upper Gila River is used in this document to denote that portion of the 
Gila River basin in New Mexico). The Salt River and Verde River are 
occupied in several reaches that are fragmented and separated by two 
large dams and reservoirs on the Verde River, and four large dams and 
reservoirs on the Salt River. Roundtail chubs also occur in canals in 
Phoenix that are fed by the lower Salt and Verde Rivers. Roundtail 
chubs inhabit several streams in the Salt River drainage, although 
survey information on the San Carlos Apache Reservation and White 
Mountain Apache Reservation is proprietary and confidential, and their 
status is not currently known; these streams include Canyon, Carrizo, 
Cedar, Cibecue, and Corduroy Creeks, and the White River (Voeltz 2002, 
pp. 82-83).
    The Arizona Game and Fish Department (AGFD) conducted a 
comprehensive status review of roundtail and headwater chub (Voeltz 
2002) in the lower Colorado River basin that included a review of all 
available current and historical survey records and estimated 
historical and current range of roundtail chub using information from 
museum collections, agency databases, records found in literature, and 
consultation with experts. The report found that roundtail chub 
populations and distribution had declined significantly from historical 
levels. Based on Voeltz (2002), roundtail chub is known to occupy only 
18 percent of its former range in the lower Colorado River basin; 
status in an additional 14 percent of its range is unknown. Based on 
the best available scientific information in Voeltz (2002), the 
roundtail chub in the lower Colorado River basin appears to occupy 
about 18 to 32 percent of its former range (approximately 497 mi (800 
km) out of the 2,796 mi (4,500 km)) considered to be formerly occupied) 
in Arizona and New Mexico. We now consider the Colorado River in the 
lower Colorado River basin to be outside the historical range of the 
species (Voeltz considered it to have been occupied); given this, 
roundtail chub has been extirpated from 672 mi (965 km) of 2,197 mi 
(3,535 km; approximately 60 percent) of its formerly occupied range. Of 
the populations for which status and threat information is available, 
all but one of the remaining natural populations are considered 
threatened by both the presence of nonnative species and habitat-
altering land uses.
    In the report, Voeltz (2002) used a classification system to report 
status and threat information. Populations were defined as an 
occurrence at a stream-specific locality. A population was considered 
``stable-secure,'' ``stable-threatened,'' or ``unstable-threatened,'' 
based on abundance, population trend, and threat information for the 
locality (see Table 1, Voeltz 2002, p. 5). Voeltz (2002, p. 5) 
considered a population ``extirpated'' if the species was no longer 
believed to occupy the site, and ``unknown'' if there are too few data 
to determine status. Note that the term ``threatened'' as used by 
Voeltz (2002, p. 5) is not the definition of ``threatened'' used in the 
Act in which a species is likely to become endangered in the 
foreseeable future, but rather is an estimate of the likelihood that a 
population is likely to become extirpated. Of 40 populations of 
roundtail chub in the lower Colorado River basin identified in the 
report, Voeltz (2002, pp. 82-87) found that none were ``stable-
secure,'' 6 were ``stable-threatened,'' 13 were ``unstable-
threatened,'' 10 were ``extirpated,'' and 11 were of ``unknown'' 
status. Populations with an ``unknown'' status in Voeltz (2002) 
included nine populations wholly or partly on Tribal lands. Tribes are 
sovereign nations and

[[Page 32357]]

survey data is proprietary and confidential, but existing survey 
information for these streams was provided and indicated occupancy. The 
remaining two populations with ``unknown'' status lacked sufficient 
information to assign a category.

 Table 1--Definitions of Status Description Categories Used to Describe
                       Roundtail Chub Populations
                           [From Voeltz 2002]
------------------------------------------------------------------------
                    Status                             Definition
------------------------------------------------------------------------
Stable-Secure (SS)...........................  Chubs are abundant or
                                                common, data over the
                                                past 5-10 years shows a
                                                stable, reproducing
                                                population with
                                                successful recruitment
                                                (survival of young to
                                                Age 2, reproductive
                                                age); no impacts from
                                                nonnative aquatic
                                                species exist; and no
                                                current or future
                                                habitat altering land or
                                                water uses were
                                                identified.
Stable-Threatened (ST).......................  Chubs are abundant or
                                                common, data over the
                                                past 5-10 years shows a
                                                reproducing population,
                                                although recruitment may
                                                be limited; predatory or
                                                competitive threats from
                                                nonnative aquatic
                                                species exist; and/or
                                                some current or future
                                                habitat altering land or
                                                water uses were
                                                identified.
Unstable-Threatened (UT).....................  Chubs are uncommon or
                                                rare with a limited
                                                distribution; data over
                                                the past 5-10 years
                                                shows a declining
                                                population with limited
                                                recruitment; predatory
                                                or competitive threats
                                                from nonnative aquatic
                                                species exist; and/or
                                                serious current or
                                                future habitat altering
                                                land or water uses were
                                                identified.
Extirpated (E)...............................  Chubs are no longer
                                                believed to occur in the
                                                system.
Unknown (UN).................................  Lack of data precludes
                                                determination of status.
------------------------------------------------------------------------

    We have updated this assessment with new data from various sources, 
particularly Cantrell (2009) as provided in Table 2 below. It is 
important to recognize that these status categories are qualitative, 
and based on very limited data in most instances. We have very little 
information on the population size, length of the stream reach, 
survivorship, recruitment (survival of young to Age 2, reproductive 
age), or age structure of these populations. These categories are also 
often based on only a few surveys conducted over decadal time scales. 
We now consider 1 population ``stable-secure,'' 8 populations ``stable-
threatened,'' 13 populations ``unstable-threatened,'' and 9 populations 
``unknown.'' Ten populations remain extirpated although we now consider 
what was called a population in the Colorado River to have been 
occupied only by transient individuals. In the nine populations with 
``unknown'' status, two (Ash Creek and Roundtree Creek) are newly 
established via translocation and have not been extant long enough to 
determine successful establishment. Information on the Black River and 
Conger Creek provided since the 2002 report resulted in 
recategorization of both of those sites from ``unknown'' to ``stable-
threatened'' and for recategorization of Eagle Creek from ``unknown'' 
to ``unstable-threatened.'' Improved status at Fossil Creek that allows 
that population to reach ``stable-secure'' is due to removal of the 
power plant and associated structures, construction of a new fish 
barrier, and chemical renovation to remove nonnative fish species. 
Recent surveys have confirmed some of the information in Voeltz's 2002 
status review; in the upper Black River, Chevelon Creek, and East Clear 
Creek, the species persists in the presence of abundant nonnative 
predators, and apparently reproduces successfully, but distribution 
appears limited, abundance is unknown, and other signs, such as 
abundance of other native fish species, indicate these native fisheries 
are deteriorating (AGFD 2005a, p. 4; 2005b, pp. 4-5; Clarkson and Marsh 
2005a, pp. 6-8; 2005b, pp. 6-7). Other roundtail chub populations in 
waters with abundant nonnative predators are less able to reproduce 
successfully and the particular circumstances at these three sites are 
worth further investigation. Roundtail chub in the lower Colorado River 
basin in New Mexico may now be extirpated. The species has long been 
considered extirpated in many Gila River tributaries in New Mexico, and 
has become very rare in the mainstem Gila River (Carman 2006, pp. 9, 
18).

  Table 2--Summary of Roundtail Chub Status and Threats by Stream Reach
               [Voeltz 2002, Cantrell 2009, service files]
------------------------------------------------------------------------
                                                  Regional historical or
            Location             Current status      current threats
------------------------------------------------------------------------
                   Management Area A--Gila River Basin
------------------------------------------------------------------------
Aravaipa Creek.................  ST              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing,
                                                  road use.
                                 ..............  Factor C: Nonnative
                                                  species.
Blue River.....................  E               Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  logging and fuel wood
                                                  cutting, recreation,
                                                  livestock grazing,
                                                  road use.
                                 ..............  Factor C: Nonnative
                                                  species.
Eagle Creek....................  UT              Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
San Francisco River............  E               Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Upper Gila River...............  UT              Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Lower Gila River...............  E               Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
San Pedro River................  E               Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.

[[Page 32358]]

 
                                 ..............  Factor C: Nonnative
                                                  species.
------------------------------------------------------------------------
                   Management Area A--Salt River Basin
------------------------------------------------------------------------
Ash Creek......................  UN              Factor A: Recreation,
                                                  logging and fuel wood
                                                  cutting, livestock
                                                  grazing.
Black River....................  ST              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, livestock
                                                  grazing, mining,
                                                  logging and fuel wood
                                                  cutting, urban and
                                                  agricultural
                                                  development.
                                 ..............  Factor C: Nonnative
                                                  species.
Canyon Creek...................  UN              Factor A: Livestock
                                                  grazing, recreation,
                                                  limited fuelwood
                                                  harvest, limited
                                                  agriculture, fisheries
                                                  and wildlife
                                                  management, and
                                                  localized municipal,
                                                  urban and rural
                                                  development and
                                                  associated water use.
                                 ..............  Factor C: Nonnative
                                                  species.
Carrizo Creek..................  UN              Factor A: Livestock
                                                  grazing, recreation,
                                                  limited fuelwood
                                                  harvest, limited
                                                  agriculture, fisheries
                                                  and wildlife
                                                  management, and
                                                  localized municipal,
                                                  urban and rural
                                                  development and
                                                  associated water use.
                                 ..............  Factor C: Nonnative
                                                  species.
Cedar Creek....................  UN              Factor A: Livestock
                                                  grazing, recreation,
                                                  limited fuelwood
                                                  harvest, limited
                                                  agriculture, fisheries
                                                  and wildlife
                                                  management, and
                                                  localized municipal,
                                                  urban and rural
                                                  development and
                                                  associated water use.
                                 ..............  Factor C: Nonnative
                                                  species.
Cherry Creek...................  ST              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  mining, recreation,
                                                  livestock grazing,
                                                  logging and fuel wood
                                                  cutting, urban and
                                                  agricultural
                                                  development.
                                 ..............  Factor C: Nonnative
                                                  species.
Cibecue Creek..................  UN              Factor A: Livestock
                                                  grazing, recreation,
                                                  limited fuelwood
                                                  harvest, limited
                                                  agriculture, fisheries
                                                  and wildlife
                                                  management, and
                                                  localized municipal,
                                                  urban and rural
                                                  development and
                                                  associated water use.
                                 ..............  Factor C: Nonnative
                                                  species.
Corduroy Creek.................  UN              Factor A: Livestock
                                                  grazing, recreation,
                                                  limited fuelwood
                                                  harvest, limited
                                                  agriculture, fisheries
                                                  and wildlife
                                                  management, and
                                                  localized municipal,
                                                  urban and rural
                                                  development and
                                                  associated water use.
                                 ..............  Factor C: Nonnative
                                                  species.
Salome Creek...................  UT              Factor A: Recreation,
                                                  logging and fuel wood
                                                  cutting, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Salt River.....................  UT              Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
White River....................  UN              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, livestock
                                                  grazing, mining,
                                                  logging and fuel wood
                                                  cutting, urban and
                                                  agricultural
                                                  development.
                                 ..............  Factor C: Nonnative
                                                  species.
------------------------------------------------------------------------
                  Management Area A--Verde River Basin
------------------------------------------------------------------------
Dry Beaver Creek...............  E               Factor A: Water
                                                  diversions,
                                                  dewatering, livestock
                                                  grazing, logging and
                                                  fuel wood cutting,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.
Fossil Creek...................  SS              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, mining,
                                                  contaminants, urban
                                                  and agricultural
                                                  development, livestock
                                                  grazing.
Oak Creek......................  UT              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, mining,
                                                  contaminants, urban
                                                  and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Roundtree Canyon...............  UN              Factor A: Recreation,
                                                  logging and fuel wood
                                                  cutting, livestock
                                                  grazing.
Verde River....................  ST              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, mining,
                                                  contaminants, urban
                                                  and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
West Clear Creek...............  ST              Factor A: Water
                                                  diversions,
                                                  dewatering, livestock
                                                  grazing, logging and
                                                  fuel wood cutting,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.
Wet Beaver Creek...............  UT              Factor A: Water
                                                  diversions,
                                                  dewatering, livestock
                                                  grazing, logging and
                                                  fuel wood cutting,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.
------------------------------------------------------------------------
              Management Area B--Bill Williams River Basin
------------------------------------------------------------------------
Big Sandy River................  E               Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing,
                                                  residential
                                                  development.
                                 ..............  Factor C: Nonnative
                                                  species.
Bill Williams River............  E               Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Boulder Creek..................  ST              Factor A: Groundwater
                                                  pumping, recreation,
                                                  livestock grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Burro Creek....................  UT              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing,
                                                  residential
                                                  development,
                                                  contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
Conger Creek...................  ST              Factor A: Groundwater
                                                  pumping, mining,
                                                  livestock grazing,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.
Francis Creek..................  UT              Factor A: Groundwater
                                                  pumping, mining,
                                                  livestock grazing,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.

[[Page 32359]]

 
Kirkland Creek.................  UT              Factor A: Groundwater
                                                  pumping, recreation,
                                                  mining, livestock
                                                  grazing, residential
                                                  development,
                                                  contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
Santa Maria River..............  UT              Factor A: Groundwater
                                                  pumping, recreation,
                                                  mining, livestock
                                                  grazing, residential
                                                  development,
                                                  contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
Sycamore Creek.................  UT              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation, mining,
                                                  livestock grazing,
                                                  residential
                                                  development,
                                                  contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
Trout Creek....................  ST              Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  recreation,
                                                  residential
                                                  development.
                                 ..............  Factor C: Nonnative
                                                  species.
Wilder Creek...................  UN              Factor A: Groundwater
                                                  pumping, mining,
                                                  livestock grazing,
                                                  recreation.
                                 ..............  Factor C: Nonnative
                                                  species.
------------------------------------------------------------------------
             Management Area C--Little Colorado River Basin
------------------------------------------------------------------------
Chevelon Creek.................  UT              Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing, contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
East Clear Creek...............  UT              Factor A: Logging and
                                                  fuel wood cutting,
                                                  recreation, mining,
                                                  livestock grazing,
                                                  contaminants.
                                 ..............  Factor C: Nonnative
                                                  species.
Little Colorado River..........  E               Factor A: Dams, water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, logging
                                                  and fuel wood cutting,
                                                  recreation, mining,
                                                  urban and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
Zuni River.....................  E               Factor A: Water
                                                  diversions,
                                                  groundwater pumping,
                                                  dewatering, mining,
                                                  contaminants, urban
                                                  and agricultural
                                                  development, livestock
                                                  grazing.
                                 ..............  Factor C: Nonnative
                                                  species.
------------------------------------------------------------------------
SS--Stable-Secure; ST--Stable-Threatened; UT--Unstable-Threatened; E--
  Extirpated; UN--Unknown.

    Populations of roundtail chub are found in five separate drainages 
that are isolated from one another (the Little Colorado River, Bill 
Williams River, Gila River, Salt River, and Verde River), and 
populations within the drainages have varying amounts of connectivity 
between them. Using large-scale watersheds, AGFD created ``management 
areas'' and ``significant conservation units'' based on currently 
occupied roundtail habitats. AGFD has utilized new genetic studies 
(Dowling et al. 2008; Schwemm 2006; See Table 2) to refine these 
management areas. Based on genetic similarity, the Verde, Salt, and 
Gila Rivers and their tributaries constitute Management Area A, the 
Bill Williams and its tributaries are Management Area B, and the Little 
Colorado River and its tributaries are Management Area C. Cantrell 
(2009, p. 9) also refined significant conservation units for management 
purposes based on genetic information (Dowling et al. 2008; Schwemm 
2006); however the mechanism for selecting these units and 
determination of stability versus instability of a management area or 
significant conservation units was not clearly described.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and implementing regulations 
at 50 CFR 424, set forth 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) the 
inadequacy of existing regulatory mechanisms; and (E) other natural or 
manmade factors affecting its continued existence. In making this 
finding, information regarding the status and threats to the Lower 
Colorado River Basin DPS of roundtail chub in relation to the five 
factors provided in section 4(a)(1) of the Act is summarized below.

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

    Roundtail chub has been eliminated from much of its historical 
range because many formerly occupied areas are now unsuitable due to 
dewatering, impoundment, channelization, and channel changes caused by 
alteration of riparian vegetation and watershed degradation (Miller 
1961, pp. 367-371; Miller 1972, pp. 240, 242; Deacon et al. 1979, pp. 
32, 34; Bestgen and Propst 1989, p. 409; Girmendonk and Young 1997, p. 
16-44; Bezzerides and Bestgen 2002, pp. 6-9, 24-33; Voeltz 2002, pp. 
87-89). In addition, areas where roundtail chub still occurs have been 
significantly altered or are currently being altered by the same and 
additional factors, including mining, improper livestock grazing, wood 
cutting, recreation, urban and suburban development, groundwater 
pumping, dewatering, dams and dam operation, contaminants, and other 
human actions (Minckley 1973, p. 101; Minckley 1985, pp. 12-15, 65-67; 
Bestgen and Propst 1989, p. 409; Bezzerides and Bestgen 2002, pp. 24-
33; Tellman et al. 1997, pp. 159-170; Voeltz 2002, pp. 87-89; McKinnon 
2006a, 2006b, 2006c, 2006d, 2006e). These activities and their effects 
on the roundtail chub are discussed in further detail below. It is 
important to recognize that in most areas where roundtail chub 
historically occurred or currently occur, two or more threats may be 
acting in combination in their influence on the roundtail chub or on 
suitability of habitat to support the species (Voeltz 2002, pp. 23-81; 
Cantrell 2009, p. 15).

[[Page 32360]]

    The modification and destruction of aquatic and riparian 
communities in the post-settlement arid southwestern United States from 
anthropogenic (human-caused) land uses is well documented (Miller 1961, 
pp. 367-371; Sullivan and Richardson 1993, pp. 35-42; Girmendonk and 
Young 1997, pp. 45-52; Tellman et al. 1997; Webb and Leake 2005, pp. 
305-310; Ouren et al. 2007, pp. 16-22). Significant loss of habitat and 
species range has also been well documented (Miller 1961, p. 365; 
Minckley 1985, pp. 4-15; Minckley and Deacon 1991, pp. 7-18), and has 
been reported specifically for the roundtail chub in the lower Colorado 
River basin (Voeltz 2002). An estimated one-third of Arizona's pre-
settlement wetlands have dried or have been rendered ecologically 
dysfunctional (Yuhas 1996). Although many of these habitat changes, and 
the greatest loss and degradation of riparian and aquatic communities 
in Arizona, occurred during the period from 1850 to 1940, (Miller 1961, 
pp. 365-371; Minckley 1985, pp. 4-15; Webb and Leake 2005, pp. 305-
310), many of these land activities continue today and are discussed in 
detail below.
Dams, Diversions, and Groundwater Withdrawal
    Major dams have been constructed throughout the historical and 
current range of the roundtail chub in the lower Colorado River basin, 
including four dams on the Gila River, four on the Salt River, and two 
on the Verde River, and have been a substantial cause in the decline of 
the species (Minckley 1985, pp. 12-14; Tellman et al. 1997, pp. 159-
170; Voeltz 2002, pp. 19-22, 44-45). Although roundtail chubs survive, 
reproduce, and can even be cultured in small ponds, they do not appear 
to be able to persist in reservoirs. Much of the lower Salt River and 
portions of the lower Verde River are now reservoirs where roundtail 
chub formerly occurred (Voeltz 2002, pp. 20, 84-85). In addition to the 
loss of flowing river habitats through inundation, dams also modify 
sediment dynamics, timing and magnitude of downstream flow, and 
temperature characteristics of habitats (Gloss et al. 2005, pp. 17-32, 
69-85). Such changes can negatively affect the distribution and 
survival of warm-water adapted native fishes like roundtail chub. 
Tailwaters of large dams are often too cold for successful reproduction 
by native warmwater fishes. Cooler water temperatures can also reduce 
the growth rates and survival of embryos and juvenile warm-water fish. 
Larvae grow more slowly, which increases their risk of predation and 
decreases accumulation of energetic reserves needed for overwinter 
survival. Cold water temperatures may slow growth and reduce 
reproductive success (Marsh 1985, p. 129; Valdez and Ryel 1994, pp. 4-
16; Muth et al. 2000, pp. 5-1-5-39). Reservoirs also capture sediment 
and discharge sediment-poor water downstream that alters channel 
characteristics (Collier et al. 1996, pp. 63-85; Gloss et al. 2005, pp. 
17-32; Wright et al. 2008, p. 4). Alteration of the magnitude and 
timing of flow and capture of sediment in reservoirs can increase water 
clarity and channel scour downstream from the dam (Collier et al. 1996, 
pp. 63-85). Changes in discharge timing and magnitude may shift 
environmental cues needed by fish for proper timing of migration and 
spawning, thereby preventing successful reproduction (Muth et al. 2000, 
pp. 5-1-5-39). Dams also prevent upstream, and to a lesser degree 
downstream, movement of all age classes to historical spawning, 
rearing, and overwintering habitat (Martinez et al. 1994, pp. 227-239; 
Schuman 1995, pp. 249-261).
    Within the range of roundtail chub in the lower Colorado River 
basin, water for human uses is supplied by reservoirs created by dams, 
surface water diversions, and groundwater pumping. The hydrologic 
connection between groundwater and surface flow of intermittent and 
perennial streams is becoming better understood. Groundwater pumping 
creates a cone of depression within the affected aquifer that slowly 
radiates outward from the well site. When the cone of depression 
intersects the hyporheic zone of a stream (the active transition zone 
between surface water and groundwater that contributes water to the 
stream itself), the surface water flow may decrease. Continued 
groundwater pumping can draw down the aquifer sufficiently to create a 
water-level gradient away from the stream and floodplain (Webb and 
Leake 2005, p. 309). Finally, complete disconnection of the aquifer and 
the stream results in dewatering of the stream (Webb and Leake 2005, p. 
309).
    Roundtail chub has been eliminated from much of its historical 
range because many formerly occupied areas are now unsuitable due to 
dewatering (Miller 1961, pp. 367-371; Miller 1972, pp. 240, 242; Deacon 
et al. 1979, pp. 32, 34; Bestgen and Propst 1989, p. 409; Girmendonk 
and Young 1997, pp. 16-44; Bezzerides and Bestgen 2002, pp. 6-9, 24-33; 
Voeltz 2002, pp. 87-89). Dams, diversions, and groundwater pumping have 
effectively eliminated much of the riverine habitat in Arizona that 
roundtail chub once occupied simply by eliminating downstream flow and 
drying much of the historical river courses (Tellman et al. 1997, pp. 
164, 169; Voeltz 2002, pp. 19-22, 44-45). In 1904, Chamberlin noted 
that a primary cause of fish extinctions in the lower Colorado River 
basin was irrigation operations including water use, preclusion of 
migration due to dams, and destruction of fish in ditches (Minckley 
1999, p. 215). Groundwater pumping and water diversions continue to 
pose a significant threat to the continued existence of the roundtail 
chub by reducing the quantity and quality of habitat (Girmendonk and 
Young 1997, p. 56), and by altering streamflow and reducing the 
frequency and magnitude of floods. Diversions also impact fish 
populations by creating barriers to fish movement and by entraining 
drifting larvae and fish into irrigation canals where they may later 
perish (Martinez et al. 1994, pp. 227-239). Chamberlin found that all 
of the flow of the San Pedro River was diverted at two dams near 
Fairbanks in 1904 (Minckley 1999, pp. 200-201). Reaches of the Verde 
River near Tapco and the urban areas in the Verde Valley contain 
numerous, significant diversion dams, and dead fishes have been 
reported in surrounding pastures following irrigation (Girmendonk and 
Young 1997, p. 56). Roundtail chubs are also diverted from the lower 
Salt River into canals in the Phoenix area, where they likely perish as 
a result of annual dewatering for canal maintenance, although some fish 
are salvaged and returned to the Salt River.
    The Service found that, in lotic systems (flowing water), roundtail 
chub habitat is essentially eliminated when flow consistently drops 
below 10 cubic feet per second (0.3 cubic meters per second) (Service 
1989, pp. 32-33). In the Verde River, the lowered water level during 
the summer irrigation season alters physical characteristics of the 
river, changing stream width and depth (Girmendonk and Young 1997, p. 
55-56), with much of the stream in the summer dry season reduced to 
isolated pools, especially in the urbanized Verde Valley area. The 
upper Gila River, in the vicinities of Cliff, Redrock, and Virden, New 
Mexico, has been entirely dewatered on occasion by diversions for 
agriculture (Bestgen 1985, p. 13). Water withdrawal alters stream flow 
regime, in part by reducing flooding (Brouder 2001, p. 302; Freeman 
2005, p. 1). Brouder (2001, p. 302) hypothesized that periodic flooding 
in the Verde River is needed to maintain roundtail chub habitat, and 
further that reductions in periodic flooding due to continued

[[Page 32361]]

water withdrawal and extended drought could lead to roundtail chub 
recruitment failure and significant population declines.
    To accommodate the needs of rapidly growing rural and urban 
populations (see the ``Urban and Rural Development'' section), surface 
water is commonly diverted to serve many industrial and municipal uses. 
These water diversions have dewatered large reaches of once perennial 
or intermittent streams, adversely affecting roundtail chub habitat 
throughout its range in Arizona and New Mexico. Many tributaries of the 
Verde River are permanently or seasonally dewatered by water diversions 
for agriculture (Paradzick et al. 2006, pp. 104-110). Water withdrawal 
(dams, diversions, and groundwater pumping) is a threat to most extant 
populations of roundtail chub in the lower Colorado River basin 
(Bestgen and Propst 1989, p. 409; Girmendonk and Young 1997, p. 56; 
Propst 1999, p. 25; Voeltz 2002, pp. 23-81; Cantrell 2009, p. 15).
    Increased urbanization and population growth results in an increase 
in the demand for water and, therefore, water development projects. 
Municipal water use in central Arizona has increased by 39 percent in 
the last 8 years (American Rivers 2006, pp. 2-3). Areas of the Verde 
River basin continue to experience explosive population growth and 
concomitant demand for water. Traditionally rural portions of Arizona 
are also predicted to experience significant growth. The populations of 
developing cities and towns of the Verde watershed are expected to more 
than double in the next 50 years, which may pose exceptional threats to 
riparian and aquatic communities of the Verde Valley (Girmendonk and 
Young 1993, p. 47; American Rivers 2006; Paradzick et al. 2006, p. 89). 
Communities in Yavapai and Gila counties such as the Prescott-Chino 
Valley and the City of Payson have seen rapid population growth in 
recent years. For example, the population in the town of Chino Valley, 
at the headwaters of the Verde River, grew by 22 percent between 2000 
and 2004; Gila County, which includes reaches of Tonto Creek and the 
Salt, White, and Black Rivers, grew by 20 percent between 2000 and 2003 
(U.S. Census Bureau 2005). Voeltz (2002, p. 35) also considered 
groundwater pumping from new development a serious threat for all 
streams of the Burro Creek drainage in the Bill Williams River basin.
    In the Verde River basin, water demands of increasing population 
density and associated development have reduced the flow of the Verde 
River, and seem likely to continue to do so. A number of researchers 
have reported that groundwater in the Big Chino aquifer is connected to 
the Verde River and that groundwater pumping of this aquifer affects 
stream flow in the mainstem Verde River (Wirt and Hjalmarson 2000, pp. 
44-47; Ford 2002, p. 1; Woodhouse et al. 2002, pp. 1-4). The 
relationship between groundwater pumping in the lower Big Chino aquifer 
and Verde River flow has been apparent since at least the early 1960s 
when a surge of pumping due to new development caused Verde River flows 
to drop significantly (Wirt and Hjalmarson 2000, p. 27). The Big Chino 
aquifer is estimated to supply approximately 80 percent of the base 
flow of the Upper Verde River (Wirt and Hjalmarson 2000, p. 44, Wirt et 
al. 2004, p. G7; Blasch et al. 2006, updated 2007, pp. 1-2). Woodhouse 
et al. (2004, pp. 1-4) also reported that numerous groundwater wells 
throughout the upper Verde River watershed have reduced the water table 
of the Verde River (Woodhouse et al. 2002, pp. 1-4). A proposed water 
project in the area, the Big Chino Water Ranch Project, will include 
infrastructure to pump groundwater in the Chino Valley and pipe it to 
nearby communities. It will include a 30 mi (48 km), 36 in. (91 cm) 
diameter pipeline that will deliver up to 2.8 billion gallons (gal) 
(12,400 acre-feet (ac-ft)) of groundwater annually from the Big Chino 
sub-basin aquifer to the rapidly growing area of Prescott Valley for 
municipal use (McKinnon 2006c; Davis 2007, pp. 1-2). This potential 
reduction or loss of baseflow in the Verde River could seasonally dry 
up large reaches of the stream.
    Roundtail chub habitat in Clear Creek and Chevelon Creek in the 
Little Colorado River watershed appears severely threatened by 
dewatering. Recent studies and assessments of the Little Colorado River 
watershed and its underlying groundwater resources indicate that these 
water resources are under increasing pressure from development (Bills 
et al. 2005). The North Central Arizona Water Supply Study Report of 
Findings (U.S. Bureau of Reclamation 2006) predicts that by the year 
2050, the human demand for water will not be met in north-central 
Arizona. Plans are underway to determine how additional water resources 
can be developed to provide for this unmet demand. Protecting water 
resources for environmental needs is included in these plans. However, 
it is likely that, with the need for additional demand and use of water 
for human uses, there will be additional stress on these aquatic 
ecosystems. In addition, there is high potential that extended drought, 
perhaps exacerbated through global climate change (see the ``Climate 
Change'' section below), will further stress water resources. Two 
hydrologic models developed to evaluate the impacts of additional 
pumping on groundwater in the C-aquifer in Arizona support these 
findings. The C-aquifer is located on the Colorado Plateau of 
northeastern Arizona, western New Mexico, and southern Colorado and is 
the aquifer that underlies the lower Colorado River Basin. Two 
groundwater models, one developed by the U.S. Geological Survey (Leake 
et al. 2005), and a second full-flow groundwater model developed to 
evaluate cumulative effects to surface water flow (Papadopulos and 
Associates 2005), have been developed for the area encompassing the C-
aquifer. Both models predicted depletion in baseflow from current and 
proposed groundwater withdrawals in lower Chevelon and Clear Creeks 
over the next 50 to 100 years. The flow model (Papadopulos and 
Associates 2005) predicted that, based on current regional pumping, the 
base flow of Lower Chevelon Creek would be zero in 60 years.
    Water use from rapidly growing communities and agricultural and 
mining interests have altered flows or dewatered significant reaches 
during the spring and summer months in some of the Verde River's 
larger, formerly perennial tributaries such as Wet Beaver Creek, West 
Clear Creek, and the East Verde River (Girmendonk and Young 1993, pp. 
45-47; Sullivan and Richardson 1993, pp. 38-39; Paradzick et al. 2006, 
pp. 104-110). The upper Gila River is also threatened by water 
diversions and water allocations. In New Mexico, a water settlement in 
2004 allows New Mexico the right to withhold 4.5 billion gal (13,800 
ac-ft) of surface water every year from the Gila and San Francisco 
Rivers (McKinnon 2006d). Project details are still under development, 
so the impact of this project on aquatic resources cannot yet be 
evaluated.
    The Arizona Department of Water Resources manages water supplies in 
Arizona and has established five Active Management Areas across the 
State (Arizona Department of Water Resources 2006). An Active 
Management Area is established by the Arizona Department of Water 
Resources when an area's water demand has exceeded the groundwater 
supply and an overdraft has occurred. In these areas, groundwater use 
has exceeded the rate that precipitation can recharge the aquifer. 
Geographically, all five Active

[[Page 32362]]

Management Areas overlap the historical distribution of the roundtail 
chub in Arizona. The declaration of these Active Management Areas 
further illustrates the current and future threats to aquatic habitat 
in these areas and is a cause of concern for the long-term maintenance 
of historical and occupied roundtail chub habitat. Such overdrafts 
reduce surface water flow of streams that are hydrologically connected 
to the aquifer under stress, and this stress can be further exacerbated 
by the surface water diversions.
Livestock Grazing
    Historical accounts of livestock grazing and its effects in Arizona 
are consistent: widespread overgrazing throughout the State in the mid- 
to late-1880s denuded rangelands and so altered watersheds that the 
landscape was changed forever. In fact, in 1906, F.M. Chamberlain 
conjectured that the alteration of landscapes was so profound that it 
had actually resulted in climate change to a more arid climate in the 
region (as cited in Minckley 1999). Similarly, Croxen (1926) describes 
changes to the Tonto National Forest resulting from poorly managed 
livestock grazing as largely running their course by the late 1880s. 
Between 1880 and 1890, the widespread improper grazing regimes that had 
denuded the landscape for 10 to 20 years or so throughout the State was 
followed by severe flooding. The end result was a rapid transition for 
many aquatic habitats from permanent, meandering streams to 
intermittent ``flashy'' arroyos (intermittent streams with higher peak 
flows and lower base flows) (Minckley and Hendrickson 1984, pp. 131-
132; Cheney et al. 1990, pp. 5, 10).
    Poorly managed livestock grazing has damaged approximately 80 
percent of stream, cienega (marsh), and riparian ecosystems in the 
western United States (Kauffman and Krueger 1984, pp. 433-435; Weltz 
and Wood 1986, pp. 367-368; Waters 1995, pp. 22-24; Pearce et al. 1998, 
p. 307; Belsky et al. 1999, p. 1) and severely altered many of the 
habitats formerly and currently occupied by roundtail chub. Livestock 
grazing today is much more strictly managed by Federal agencies and 
Tribes because the effects of grazing and mismanagement are now better 
understood and have been well documented. For example, Stromberg and 
Chew (2002, p. 198) and Trimble and Mendel (1995, p. 243) discuss the 
propensity for poorly managed cattle to remain within or adjacent to 
riparian communities, a behavior that is more pronounced in arid 
regions (Trimble and Mendel 1995, p. 243). In one rangeland study, it 
was concluded that 81 percent of the vegetation that was consumed, 
trampled, or otherwise removed was from a riparian area, which amounted 
to only 2 percent of the total grazing space (Trimble and Mendel 1995, 
p. 243). Additionally, grazing rates can be 5 to 30 times higher in 
riparian areas (Trimble and Mendel 1995, p. 244). But as a direct 
result of this research, management agencies now exclude livestock 
grazing from many riparian areas and streams, or only permit light and 
seasonal grazing in these areas. We summarize here the effects of 
livestock grazing, but it is important to note that these effects only 
become tangible if livestock grazing is poorly managed. If properly 
managed, there is some evidence that affects to wildlife habitat can be 
positive. In this respect, livestock grazing is largely a threat of the 
past, and if properly managed, is not likely a threat. Although more 
research is needed, livestock grazing strategies can be developed that 
are compatible and even complementary with fisheries management (Platts 
1989, p. 103; Vavra 2005, p. 128). The American Fisheries Society 
Policy Statement on livestock grazing concludes that ``it is our strong 
contention that when properly implemented and supervised, grazing could 
become an important management tool benefiting fish and wildlife 
riparian habitats'' (American Fisheries Society 2009).
    Livestock grazing occurs throughout the range of roundtail chub in 
the lower Colorado River basin in all drainages in which the species 
occurs (Tellman et al. 1997, p. 167; Propst 1999, p. 25; Voeltz 2002, 
pp. 23-88), and has resulted in the degradation of roundtail chub 
habitat from a number of mechanisms. Livestock directly affect 
roundtail chub habitat through removal of riparian vegetation (Clary 
and Webster 1989, p. 1; Clary and Medin 1990, p. 1; Schulz and 
Leininger 1990, p. 295; Armour et al. 1991, pp. 8-10; Fleishner 1994, 
pp. 630-631), which can result in reduced bank stability, fewer pools, 
and higher water temperatures (Kauffman and Krueger 1984, p. 432; 
Minckley and Rinne 1985, p. 150; Schulz and Leininger 1990, p. 295; 
Fleishner 1994, pp. 630-631; Belsky et al. 1999, pp. 8-12). Livestock 
grazing can also cause increased sediment in the stream channel, due to 
streambank trampling and riparian vegetation loss (Weltz and Wood 1986, 
pp. 367-368; Waters 1995, pp. 22-24; Pearce et al. 1998, p. 307). 
Livestock physically alter streambanks through trampling and shearing, 
leading to bank erosion (Trimble and Mendel 1995, p. 244; Clary and 
Webster 1989, pp. 7-8). In combination, loss of riparian vegetation and 
bank erosion can alter channel morphology, including increased erosion 
and deposition, downcutting, and an increased width/depth ratio, all of 
which can lead to a loss of pool habitats and loss of shallow side and 
backwater habitats (Trimble and Mendel 1995, pp. 243-250; Belsky et al. 
1999, pp. 1-2). Pool habitats are required by the roundtail chub, and 
shallow side and backwater habitats are used by larval chubs for 
sheltering from larger bodied predators and for feeding (Minckley 1973, 
p. 100; Brouder et al. 2000, pp. 6-7; Minckley and DeMarais 2000, p. 
255).
    Although livestock grazing is unlikely to be a threat if properly 
managed, physical developments necessary to support livestock grazing 
can also have direct effects on roundtail chub. Water sources are 
essential to livestock operations, and numerous stock tanks, stream 
diversions, and various types of groundwater pumps are utilized to 
provide water for livestock (Valentine 1989, pp. 413-431). This diverts 
water from natural surface waters, including streams supporting 
roundtail chub (see ``Dams, Diversions, and Groundwater Withdrawal'' 
section above). In addition to livestock developments, thousands of 
miles of fencing are needed to partition cattle into pastures or 
rotation-type grazing systems (Valentine 1989, pp. 435-449). 
Maintaining this infrastructure requires a substantial network of 
roads. Road use and maintenance have been a major factor in altering 
the morphology and habitat of streams in the Southwest (see ``Road 
Construction, Use, and Maintenance'' section below).
    Livestock can indirectly impact aquatic and riparian habitats at a 
watershed level though soil compaction, altered soil chemistry, and 
reductions in upland vegetation cover; these changes lead to an 
increased severity of floods and sediment loading, lower water tables, 
and altered channel morphology (Rich and Reynolds 1963, p. 222; Orodho 
et al. 1990, p. 9; Schlesinger et al. 1990, p. 1043; Belsky et al. 
1999, p. 1). One consequence of these changes in watershed function is 
a reduction in the quantity and quality of pool habitat. Lowered water 
tables result in the direct loss of pool habitats, simply because water 
is not available to form pools. Increased erosion and sedimentation 
results in filling of pools with sediments. Channel incision and 
increased flood severity eliminate pools through bed scour, and reduce 
habitat complexity by creating shallow, uniform streambeds (see Trimble 
and Mendel

[[Page 32363]]

1995, pp. 245-251; Belsky et al. 1999, pp. 25-35). Much of Arizona's 
rivers and streams were modified by livestock grazing in this way by 
the mid 1900s (Miller 1961, pp. 394-395; Minckley 1999, p. 215), and 
the effects to aquatic habitat from that historical modification remain 
today.
    Livestock use has been shown to alter the composition and community 
structure of the aquatic fauna (regional animal life), which can also 
indirectly impact roundtail chub by reducing the quantity and quality 
of food sources. Altered stream channel characteristics, sediment 
deposition, changes in substrate size, and nutrient cycle changes are 
all potential effects of livestock grazing that can alter aquatic 
invertebrate communities (Li et al. 1994, pp. 638-639; Hoorman and 
McCutcheon 2005, p. 3), resulting in changes to the food base for 
aquatic vertebrates, particularly fish. Few detailed studies of changes 
in aquatic faunal communities have been completed on streams in the 
range of the roundtail chub, but given the widespread occurrence of 
ongoing and historical livestock grazing, changes in aquatic faunal 
community has likely occurred in many streams within historical range 
of roundtail chub.
    Livestock grazing results in loss of aquatic habitat complexity, 
thus reducing diversity of habitat types available and altering fish 
communities (Li et al. 1987, pp. 627, 638-639). In the arid west, loss 
of habitat complexity has been a major contributing factor in declines 
of native fishes and amphibians and in the displacement of native fish 
species by nonnative species (Bestgen and Propst 1986, p. 209; Minckley 
and Rinne 1991, pp. 2-5; Baltz and Moyle 1993, p. 246; Lawler et al. 
1999, p. 621). Livestock grazing has also contributed significantly to 
the introduction and spread of nonnative aquatic species through the 
proliferation of stock tanks (manmade ponds that are water sources for 
livestock) which serve as created habitat for nonnative species (Rosen 
et al. 2001, p. 24; Hedwall and Sponholtz 2005, pp. 1-5; Service 2008, 
pp. 46-51). The spread of nonnative species is a threat to roundtail 
chub because these nonnative species prey on and compete with roundtail 
chub (see ``Nonnative Species'' section below for more discussion).
    Another direct effect of livestock grazing in intermittent aquatic 
habitats is the potential for livestock to drink occupied roundtail 
chub habitat dry under certain conditions, completely eliminating all 
habitat and killing any roundtail chub present. Vallentine (1989, pp. 
413-431) states that cattle need an average of 12 to 15 gal (45 to 57 
liters (L)) of water per day per animal, and that this varies 
seasonally because of the moisture content of forage, ambient 
temperature and humidity, and other factors. Griffith (1999, p. 1) 
states that at 10 [deg]C (50 [deg]F), a cow may consume about 5 to 7 
gal (19 to 26 L) per day, but the amount increases by 0.4 gal (1.5 L) 
per day for every one-degree increase in air temperature; thus at 35 
[deg]C (95 [deg]F) the same cow will drink an average of 24 gal (91 L) 
per day. Roundtail chub can be limited to small isolated pool habitats 
during the driest times of the year that can be as little as several 
hundred gal (1-2000 L) in volume, and have flow so low that inflow is 
essentially equal to or less than evaporation; several cows could 
completely dry such habitats in a matter of days, especially in times 
of drought. Gila chub, a related species, and its habitat, is believed 
to have been eliminated in this manner from portions of Indian Creek in 
2002-2003 (Service 2006, p. 10).
    Livestock grazing also contributed to shrub invasion of grasslands 
(Brown and Archer 1999, p. 2385). Shrub invasions decrease biodiversity 
and create ecosystem instability in desert ecosystems (Baez and Collins 
2008). Shrub invasion also can lead to a greater amount of water loss 
through plants, which contributes to desertification (Knapp et al. 
2008, p. 621). Fire regimes are also altered by shrub invasion 
(Richburg et al. 2001, p. 104), and altered fire regimes pose a threat 
to roundtail chub due to the effects of wildfire on watersheds and 
direct effects of ash and sediment flows following wildfires (see 
``High-Intensity Wildfires'' section below).
    All extant populations of roundtail chub are subject to some level 
of livestock grazing in the watershed, but specific problems associated 
with livestock grazing have only been noted in four streams (Chevelon, 
East Clear, Burro, and Salome Creeks) (Voeltz 2002; Cantrell 2009, p. 
15). In Chevelon Creek, Arizona Department of Environmental Quality 
water quality standards for sediment and turbidity (muddiness of water) 
were not met due to grazing and high channel erosion, habitat 
modification, and unsatisfactory watershed condition for the watershed 
(Voeltz 2002, p. 27). In the Verde River, Girmendonk and Young (1997, 
p. 53) noted cattle grazing had a major impact on both upland and 
aquatic communities due to trampled banks and heavily grazed vegetation 
from Sullivan Lake downstream to Cottonwood. However, we note that in 
most streams currently occupied by roundtail chub, grazing has been 
removed from the riparian area. For example, livestock grazing has 
since been removed from that portion of the Verde River discussed by 
Girmendonk and Young (1997).
    The above discussion illustrates that poorly managed livestock 
grazing can adversely affect roundtail chub in several ways, from 
direct loss due to livestock water and vegetation consumption and 
trampling, to indirect habitat alteration from changes in the 
watershed. In general, properly managed livestock grazing utilizes 
rest-rotation grazing systems that exclude riparian areas or limit 
their use to the winter season, and utilize monitoring systems to 
ensure that use of uplands and riparian areas are not overgrazed. When 
livestock grazing is well managed in this manner it is not likely a 
threat to the roundtail chub. The capability exists to create livestock 
grazing strategies that are compatible and even complementary to 
maintaining fisheries habitat, although more research is needed in this 
regard (Platts 1989, p. 103; Vavra 2005, p. 128).
Urban and Rural Development
    Urban and rural development are considered a threat in every stream 
currently occupied by roundtail chub (Cantrell 2009, p. 18). 
Development can affect roundtail chub and its habitat through direct 
alteration of streambanks and floodplains from construction of homes 
and businesses, as well as from numerous related impacts. Tellman et 
al. (1997, pp. 92-93) listed the following impacts to rivers in Arizona 
from urban and rural development: increased use of floodplain for homes 
and businesses, sand and gravel mining in the floodplain for 
construction materials, pollution from trash and wastewater in river 
bed, depletion of water supplies, increased land covered by impervious 
surfaces with greater surface runoff and less infiltration, building of 
flood control structures, and increased recreational impacts. On a 
broader scale, development alters the watershed with consequent changes 
in the hydrology, sediment regimes, and pollution input (Leopold 1997, 
pp. 97-102; Horak 1989, p. 42; Medina 1990, p. 351; Reid 1993, pp. 48-
51; Waters 1995, pp. 42-44; Wheeler et al. 2005, p. 141).
    Development changes watersheds from land surfaces where 
precipitation can infiltrate the soil and reach a stream slowly as 
subsurface flow, to one with impervious surfaces such as rooftops, 
asphalt, and compacted soils (Schueler 1994, p. 100; 1995, p. 233; 
Wheeler et al. 2005, p. 151). These impervious surfaces capture 
precipitation and route it quickly and directly into gutters,

[[Page 32364]]

storm drains, overland flow, and streams (Hollis 1975, p. 431; Wheeler 
et al. 2005, p. 151). Similarly, precipitation falling on impervious 
surfaces without direct hydraulic connections to streams may reach 
streams quickly as overland flow (Horton 1945, p. 275; Leopold 1973, p. 
1845; Wheeler et al. 2005, p. 151). Thus, urbanization fundamentally 
alters the delivery of water to streams (Environmental Protection 
Agency 2008, p. 1). These changes in precipitation delivery alter 
stream flow regimes. Peak flow volume from precipitation events 
increases (Hollis 1975, p. 431; Neller 1988, p. 1; Booth 1990, pp. 407-
417; Clark and Wilcock 2000, p. 1763; Rose and Peters 2001, p. 246; 
Wheeler et al. 2005, p. 151). These changes increase the frequency and 
magnitude of floods (Hollis 1975, p. 431; Wheeler et al. 2005, p. 151), 
which cause a stream to increase its channel capacity by eroding its 
banks, downcutting its channel, or both (Hammer 1972, p. 1530; Leopold 
1973, p. 1845; Booth 1990, p. 1752; Pizzuto et al. 2000, p. 79; Brown 
and Caraco 2001, pp. 16-19; Wheeler et al. 2005, p. 151). Because 
natural surfaces in a watershed transmit water slowly to the stream as 
subsurface flow, base flow in a stream is often from subsurface flow 
and groundwater that steadily contributes flow between precipitation 
events. The impervious surfaces caused by development alter this 
process, preventing precipitation from infiltrating, and resulting in a 
reduction in base flow of the stream (Simmons and Reynolds 1982, p. 
1752; Wang et al. 2001, p. 255; 2003, p. 825; Wheeler et al. 2005, p. 
151). Development within and adjacent to riparian areas has proven to 
be a significant threat to riparian and aquatic biological communities 
(Medina 1990, p. 351), with even low levels of development causing 
adverse impacts within a watershed (Wheeler et al. 2005, p. 142). 
Development can alter the nature of stream flow dramatically, changing 
streams from perennial to ephemeral, which can have direct consequences 
to stream fauna (Medina 1990, pp. 358-359). Medina (1990, pp. 358-359) 
found that development reduced vegetation in streams and changed flow 
regimes, which resulted in a decrease in abundance of fish.
    Development in and near stream courses usually results in removal 
of riparian vegetation, which leads to a number of changes to streams 
(Wheeler et al. 2005, p. 151). Riparian vegetation stabilizes 
streambanks and reduces bank erosion (Beeson and Doyle 1995, p. 983; 
Wynn and Mostaghimi 2006, p. 400), and helps moderate urban stream 
temperatures (LeBlanc et al. 1997, p. 445). Because riparian vegetation 
contributes leaves, wood, organic debris, and terrestrial invertebrates 
to streams, vegetation removal can often drastically alter food webs in 
streams (Vannote et al. 1980, p. 130; Hawkins and Sedell 1981, p. 387; 
Reid 1993, p. 74). Also, large woody debris can be an important 
component of stream channels because the debris stabilizes stream banks 
(Keller and Swanson 1979, p. 361), creates pools (Keller and Swanson 
1979, p. 361; Rinne and Minckley 1985, p. 150), and provides habitat 
for macroinvertebrates (Benke et al. 1985, pp. 8-13; Rinne and Minckley 
1985, p. 150) and fishes (Angermeier and Karr 1984, p. 716; Flebbe and 
Dolloff 1995, p. 579). Riparian vegetation also moderates stream 
temperatures (LeBlanc et al. 1997, p. 445). In small and medium-sized 
streams, riparian vegetation shades and cools the stream; loss of 
riparian vegetation contributes to warming of the stream (Barton et al. 
1985, p. 365; LeBlanc et al. 1997, p. 445). Wang et al. (2003, p. 825) 
found that the maximum daily water temperature of streams in urbanized 
settings in Wisconsin and Minnesota increased by 0.25 [deg]C (0.5 
[deg]F) with every 1 percent increase in the impervious area of the 
watershed.
    Urban streams enlarge their channels by eroding their banks; this 
erosion, together with runoff from urban construction activities, adds 
fine sediment to the stream (Waters 1995, p. 43; Trimble 1997, p. 1442; 
Wheeler et al. 2005, p. 151), increasing turbidity, which can alter 
stream habitat productivity, adversely affect the food base for fish, 
eliminate rearing habitats, and fill in pool habitat (Waters 1995, p. 
43). Because urbanization typically results in loss of riparian 
vegetation as areas near streams are cleared, riparian areas can lose 
the natural ability to absorb and filter out metals, fine sediment, and 
nutrients from overland runoff (McNaught et al. 2003, p. 7).
    Development can affect water quality in a number of ways. Urban 
runoff contains a variety of chemical pollutants including petroleum, 
metals, and nutrients from a variety of sources such as automobiles and 
building materials (Wheeler et al. 2005, p. 153). Some pollutants 
contain the nutrients nitrogen and phosphorus, which can cause a body 
of water to become nutrient-enriched and stimulate the growth of 
aquatic plant life resulting in the depletion of dissolved oxygen. This 
can adversely affect fish by reducing dissolved oxygen to lethal levels 
(Hassler 1947, pp. 383-384; Cantrell 2009, p. 15). Development also 
leads to increases in the number of dumps and landfills that leach 
contaminants into ground and surface water, reducing water quality and 
thereby degrading roundtail chub habitat. Similarly, wastewater 
treatment plants that accompany development also can contaminate ground 
and surface water (Winter et al. 1998, p. 66). Pharmaceuticals and 
personal care products also may contain hormones, which are present in 
wastewater, and can have significant adverse effects to fishes, 
particularly fish reproduction (Kime 1995, p. 52; Rosen et al. 2007, 
pp. 1-4). The use of pesticides is also a source of water quality 
contamination from agricultural and residential use, which can have 
lethal and sublethal effects to fish (Ongley 1996). The use of 
pesticides occurs adjacent to 9 populations of roundtail chub in 
Arizona (Cantrell 2009, p. 12).
    The physical and chemical alterations of stream systems due to 
urbanization cause significant changes to the stream biological 
community (Wheeler et al. 2005, p. 153). Urbanized streams have fewer 
numbers and species of macroinvertebrates (Richards and Host 1994, p. 
195; Kemp and Spotila 1997, p. 55; Kennen 1998, p. 3), and exhibit 
reduced biological health (Kennen 1998, p. 3). Urban streams also have 
lower overall abundance and diversity of fishes (Tramer and Rogers 
1973, p. 366; Scott et al. 1986, p. 555; Medina 1990, p. 351; Weaver 
and Garman 1994, p. 162; Wang et al. 2000, p. 255; 2003, p. 825). 
Little is known about how urban development and the corresponding 
physical and chemical changes in streams result in changes in the 
stream ecosystem, although the physical changes appear more important 
in this process than the chemical changes (Wheeler et al. 2005, p. 
154).
    The net result of urbanization for roundtail chub is a decrease in 
habitat suitability, most significantly through a reduction in stream 
flow, although also through an increase in the probability of the 
presence of nonnative aquatic species that prey on and compete with 
roundtail chub (see ``Nonnative Species'' section below). As described 
above, development typically involves increased water use in the form 
of diversions of water from both surface flows and connected 
groundwater (Glennon 1995, pp. 133-139). The physical changes 
associated with development also result in a more ``flashy'' system, as 
described above, where runoff from precipitation rapidly exits the 
watershed, increasing flood flows, and decreasing base flow. These 
hydrologic changes can lead to streams

[[Page 32365]]

changing from perennial to intermittent, and result in a corresponding 
decrease in fish abundance (Medina 1990, p. 351).
    The effects of urban and rural development are expected to increase 
as human populations increase. Development has continually been 
increasing in the southwestern United States. Arizona increased its 
population by 394 percent from 1960 to 2000, and is second only to 
Nevada as the fastest growing State in terms of human population 
(Social Science Data Analysis Network 2000, p. 1). Growth rates in 
Arizona counties with historical or extant roundtail chub populations 
are also significant and increasing: Maricopa (463 percent); Cochise 
(214 percent); Yavapai (579 percent); Gila (199 percent); Graham (238 
percent); Apache (228 percent); Navajo (257 percent); Yuma (346 
percent); LaPaz (142 percent); and Mohave (1,904 percent) (Social 
Science Data Analysis Network 2000). Population growth trends in 
Arizona are expected to continue into the future. The Phoenix 
metropolitan area, founded in part due to its location near the 
junction of the Salt and Gila Rivers, is a population center of 3.6 
million people. The Phoenix metropolitan area is the sixth largest in 
the United States and is located in the fastest growing county in the 
United States since the 2000 census (McKinnon 2006a). Traditionally 
rural portions of Arizona are also predicted to see huge increases in 
human population. Developing cities and towns of the Verde watershed 
are expected to more than double in the next 50 years, which, as 
described above, is expected to threaten riparian and aquatic 
communities of the Verde Valley where roundtail chubs occur (Girmendonk 
and Young 1993, p. 47; American Rivers 2006; Paradzick et al. 2006, p. 
89). Chino Valley, at the headwaters of the Verde River, grew by 22 
percent between 2000 and 2004. Gila County, which includes reaches of 
Tonto Creek and the Salt, White, and Black Rivers, grew by 20 percent 
between 2000 and 2003 (U.S. Census Bureau 2005). In New Mexico, a water 
settlement in 2004 allows New Mexico the right to withhold 4.5 billion 
gal (13,800 ac-ft) of surface water every year from the Gila and San 
Francisco Rivers (McKinnon 2006d). Project details are still under 
development, so the impact of this project on aquatic resources has not 
yet been evaluated; however, the project represents another potential 
withdrawal of water from occupied habitat.
    Given the arid nature of the Southwest, the predictions of further 
growth in an already large population center, and the adverse impacts 
to aquatic habitats that are associated with development, development 
will continue to be a threat to the roundtail chub. Urban and rural 
development are considered a threat in every stream currently occupied 
by roundtail chub (Cantrell 2009, p. 15).
Road Construction, Use, and Maintenance
    Roads are a threat to roundtail chub and its habitat due to a 
variety of factors including fragmentation, modification, and 
destruction of habitat; increase in genetic isolation; facilitation of 
the spread of nonnative species via human vectors; increases in 
recreational access and the likelihood of subsequent, decentralized 
urbanization; and contributions of contaminants to aquatic communities 
(Burns 1972, p. 1; Barrett et al. 1992, p. 437; Eaglin and Hubert 1993, 
p. 884; Warren and Pardew 1998, p. 637; Waters 1995, p. 42; Jones et 
al. 2000, pp. 82-84; Angermeier et al. 2004, pp. 19-24; Wheeler et al. 
2005, pp. 145, 148-149).
    Construction and maintenance of roads and highways near riparian 
areas can be a source of sediment and pollutants (Waters 1995, p. 42; 
Wheeler et al. 2005, pp. 145, 148-149). Sediment can adversely affect 
fish populations by interfering with respiration; reducing the 
effectiveness of fish's visually-based hunting behaviors; and filling 
in interstitial spaces of the substrate, which reduces reproduction and 
foraging success of fish (Wheeler et al. 2005, p. 145). Excessive 
sediment also fills in intermittent pools that roundtail chub utilize 
as habitat. Fine sediment pollution in streams impacted by highway 
construction without the use of sediment control structures was 5 to 12 
times greater than control streams (Wheeler et al. 2005, p. 144). 
Excessive sediment can also affect the ability of roundtail chubs to 
forage. Sedimentation can alter the aquatic macroinvertebrate 
community, thereby reducing the food base for roundtail chubs. 
Increased turbidity may impede the ability of roundtail chubs to forage 
by reducing underwater visibility (Barrett et al. 1992, p. 437; Waters 
1995, pp. 173-175).
    Contaminants (hydrocarbons such as petroleum based products, and 
metals, including iron, zinc, lead, cadmium, nickel, copper, and 
chromium) are associated with highway construction and use (Foreman and 
Alexander 1998, p. 220; Wheeler et al. 2005, pp. 146-149). Many of 
these contaminants are suspected toxicants to aquatic organisms. Few 
studies have addressed the toxicity of highway runoff, but some 
comparisons of macroinvertebrate communities above and below highway 
crossings indicate that there are reductions in diversity and 
pollution-sensitive species below highway crossings, especially where 
small streams receive runoff from large highway sections (Wheeler et 
al. 2005, p. 148). In areas with cold winter weather conditions, 
deicing is common to clear snow and ice from roadways. Deicing can 
contribute sodium chloride and other chemical contaminants to water 
ways, reducing water quality, which can cause fish stress or mortality 
(Wheeler et al. 2005, p. 147). Roads also inevitably contribute to 
contaminant spills from vehicle accidents. Most hazardous chemicals are 
transported by trucks, and such spills are common and can contaminate 
water bodies and cause fish kills (Wheeler et al. 2005, pp. 147-148).
    Road construction can also impact roundtail chub through physical 
changes to the stream channel. Channelization, often a necessary 
component of urban road construction, can have numerous effects on the 
natural structure and ecosystem function of stream systems (Poff et al. 
1997, p. 773; Poole 2002, p. 641). As discussed in the ``Logging, Fuel 
Wood Cutting, Mining, and Channelization'' section, channelization can 
affect roundtail chub habitat by reducing its complexity, eliminating 
cover, reducing nutrient input, improving habitat for nonnative 
species, changing sediment transport, altering substrate size, and 
reducing the length of the stream and therefore the amount of aquatic 
habitat available (Gorman and Karr 1978, p. 507; Simpson et al. 1982, 
pp. 122-132; Propst 1999, p. 25; Schmetterling et al. 2001, p. 6).
    Roads can restrict the movement of stream fishes, resulting in 
populations becoming more isolated and fragmented. Culverts, a common 
feature of road stream crossings, are a well-known barrier to fish 
movement. Culverts themselves provide poor fish habitat due to low-
bottom complexity and uniformly high-flow velocities (Slawski and 
Ehlinger 1998, p. 676). Fish movement is inhibited or prevented by high 
current velocities and shallow depths inside culverts, along with 
vertical drops commonly associated with the culvert outflow (U.S. 
Department of Transportation 2007, pp. 3-9). Warren and Pardew (1998, 
p. 637) found that overall fish movement was an order of magnitude 
lower through culverts than through other crossing types or natural 
channels in small streams. Such barriers can isolate fish populations, 
resulting in reduced

[[Page 32366]]

genetic diversity and increased probability of extinction due to 
demographic instability and impeded recolonization. Fragmentation of 
roundtail chub habitat increases the probability of local extirpation 
(Fagan et al. 2002, p. 3250).
    By definition, roads create access to otherwise inaccessible areas 
or increase access to previously remote areas. This increased access 
results in increased human visitation, thereby increasing the frequency 
and significance of anthropogenic threats to aquatic ecosystems and 
further fragmenting the landscape. Further, increased access often 
leads to increased urban and agricultural development. Urbanization is 
the most significant of these development activities; it alters a 
watershed, such as through building construction, which changes rural 
areas from such uses as farming and grazing to residential and 
industrial areas. Wheeler et al. (2005; pp. 149-150) concluded that 
``new highways clearly and purposely provide impetus for urban 
development'' although they noted that few studies, if any, have 
specifically documented this. Roads nonetheless do clearly have a 
relationship to urban and rural development, which can alter physical 
and chemical characteristics of streams due to increases in 
contaminants and changes to the watershed that alter stream flow, as 
discussed in the ``Urban and Rural Development'' section above.
Recreation
    As discussed above, population growth trends are expected to 
continue into the future throughout the range of the roundtail chub in 
the lower Colorado River basin, dramatically increasing human 
populations. Expanding population growth leads to higher demand for 
recreational opportunities and recreational use. In the arid Southwest, 
the human desire to recreate in or near water, and the relative 
scarcity of such recreational opportunities, tends to focus impacts on 
riparian areas. Recreation-related impacts to aquatic ecosystems are 
particularly evident along stream reaches of the Salt and Verde River 
watersheds near the Phoenix metropolitan area, which are visibly 
degraded by ongoing use. Impacts of recreation are highly dependent on 
the type of activity, with activities such as hiking having little 
impact and activities such as off-highway vehicle (OHV) use potentially 
having severe impacts on aquatic habitats.
    An example of a recreation use impacted area within the existing 
distribution of the roundtail chub is the Verde Valley. The reach of 
the Verde River that winds through the Verde Valley receives a high 
amount of recreational use from people living in central Arizona 
(Paradzick et al. 2006, pp. 107-108). Increased human use results in 
trampling of nearshore vegetation and reduced water quality. 
Recreational impacts in Fossil Creek illustrate that such damage can be 
quite severe. Fossil Creek is a tributary of the Verde River and an 
extant locality of roundtail chub. A number of environmental groups 
recently sent a letter to the Coconino National Forest requesting 
emergency action to address the effects of ongoing recreational use in 
Fossil Creek. The authors cited excessive and damaging impacts of 
recreational uses on the creek and riparian habitat, including vehicles 
crushing vegetation, proliferation of social trails, kayak impacts, 
severe sanitation deficiencies, and an exceptional amount of trash 
(American Rivers et al. 2007, pp. 1-4). The effects to roundtail chub 
from these actions are unknown, but potentially adverse.
    OHV use has grown considerably in Arizona, and is a recreational 
use that can have severe adverse impacts to natural areas. As of 2007, 
385,000 OHVs were registered in Arizona (a 350 percent increase since 
1998) and 1.7 million people (29 percent of the Arizona's public) 
engaged in off-road activity from 2005-2007. Over half of OHV users 
reported that driving off-road was their primary activity, versus using 
the OHV for the purpose of access or transportation to hunting, 
fishing, or hiking. Ouren et al. (2007, pp. 16-22) provide additional 
data on the effects of OHV use on wildlife. OHV trails often travel 
through undeveloped habitat and cross directly through water bodies. 
OHV use may also reduce vegetation cover and plant species diversity, 
reducing infiltration rates, increasing erosion, and reducing habitat 
connectivity (Ouren et al. 2007, pp. 6-7, 11, 16). As discussed above, 
reducing vegetative cover and increasing sedimentation is a result of 
other land uses as well, such as livestock grazing and urbanization, 
and can have numerous adverse effects to roundtail chub. Voeltz (2002) 
noted specific OHV use-related problems with recreation in two streams 
with known populations of roundtail chub, the upper Gila River and Oak 
Creek. Recreation occurs in every stream occupied by roundtail chub in 
the lower Colorado River basin (Cantrell 2009, p. 15).
Logging, Fuel Wood Cutting, Mining, and Channelization
    Logging and mining were more widespread historically and likely 
were responsible for alteration of much of the roundtail chub's 
historical habitat. Chamberlain in 1904 listed mining as one of three 
primary causes of ``extinction'' of fishes in the lower Colorado River 
basin (along with vegetation removal from grazing, logging and other 
activities, and water use) (Minckley 1999, p. 215). The current mining 
of sand, gravel, iron, gold, copper, or other materials remains a 
potential threat to the habitat of roundtail chub for many of these 
same reasons. Drilling for fuels such as oil and natural gas has very 
similar effects (Hartman 2007, p. 1) and is occurring within the range 
of the roundtail chub in Arizona (Cantrell 2009, p. 12). The effects of 
mining activities on populations include adverse effects to water 
quality and lowered flow rates due to dewatering of nearby streams 
needed for mining operations (Arizona Department of Environmental 
Quality 1993, pp. 61-63). Sand and gravel mining removes riparian 
vegetation and destabilizes streambanks, resulting in habitat loss for 
the roundtail chub (Brown et al. 1998, p. 979). Voeltz (2002, pp. 34-
35, 42) identified mining as a significant threat in Boulder, Burro, 
and Eagle Creeks due to the release of toxic effluents into aquatic 
systems from mining operations, and water depletion for use in mining 
operations, and noted that contaminants in the form of acidified flows 
originating from mining operations in Cananea, Mexico, have been 
documented in the past in the San Pedro River, a stream in which the 
roundtail chub no longer occurs. Girmendonk and Young (1997, p. 35) 
noted that sand and gravel mining on West Clear Creek may have limited 
the suitability of that stream to support roundtail chub near the mouth 
of the Verde River. Mining is a land use in the basins of 24 out of 31 
currently extant roundtail chub populations (Voeltz 2002; Cantrell 
2009).
    Logging and fuel wood cutting is largely a threat of the past 
(resulting from previous management practices no longer in place), 
although these activities resulted in profound changes in many streams 
of the Southwest including those in which the roundtail chub occurs 
(Minckley and Rinne 1985, pp. 150-151; Minckley 1999, p. 216). The 
alteration of watersheds resulting from logging is deleterious to fish 
and other aquatic life forms (e.g., Burns 1972, p. 1; Eaglin and Hubert 
1993, p. 844), largely due to increases in surface

[[Page 32367]]

runoff, sedimentation, and mudslides, and the destruction of riparian 
vegetation (Lewis 1998, p. 55; Jones et al. 2000, p. 81). All of these 
effects negatively impact fish (Burns 1972, p. 15; Eaglin and Hubert 
1993, p. 844; Barrett et al. 1992, p. 437; Warren and Pardew 1998, p. 
637) by lowering water quality and reducing the quality and quantity of 
pools, either by filling them with sediment, reducing the quantity of 
large woody debris necessary to form pools, or imposing barriers to 
movement. Logging is a land use in the watersheds of 17 of the 
remaining 31 streams known to contain roundtail chub populations 
(Voeltz 2002).
    Channelization of streams is also a major factor in loss of habitat 
for roundtail chub. The U.S. Environmental Protection Agency defines 
channelization as: ``any activity that moves, straightens, shortens, 
cuts off, diverts, or fills a stream channel, whether natural or 
previously altered. Such activities include the widening, narrowing, 
straightening, or lining of a stream channel that alters the amount and 
speed of the water flowing through the channel. Examples of 
channelization are: lining channels with concrete; pushing gravel from 
the stream bed and placing it along the banks; and placing streams into 
culverts'' (U.S. Environmental Protection Agency 2005, p. 1). 
Channelization has occurred or is occurring in roundtail chub habitats 
to drain marshes and reclaim bottomlands for agriculture or roads 
(Hendrickson and Minckley 1984, p. 131; Propst 1999, p. 25); to create 
irrigation diversions; to control mosquitoes; to reduce 
evapotranspiration and speed water delivery to downstream metropolitan 
and agricultural areas (U.S. Soil Conservation Service 1949, p. 3; 
Burkham 1970, p. B1); and as flood control to protect fields, 
buildings, or structures such as bridges (Pearthree and Baker 1987, p. 
49). Channelization can affect roundtail chub habitat by reducing its 
complexity, eliminating cover, reducing nutrient input, improving 
habitat for nonnative species, changing sediment transport, altering 
substrate size (usually from coarse sediments like gravel and sand to a 
finer silt substrate), and reducing the length of the stream and 
therefore the amount of aquatic habitat available (Gorman and Karr 
1978, p. 513; Simpson et al. 1982, pp. 122-132; Propst 1999, p. 25; 
Schmetterling et al. 2001, p. 6; U.S. Environmental Protection Agency 
2005, pp. 1-4). Moyle (1976, p. 179) compared channelized and 
unchannelized sections of a California stream and found a two-thirds 
reduction in the biomass of fish and invertebrates in channelized 
locations compared to unchannelized reaches, as well as differences in 
fish and macroinvertebrate (animals lacking a vertebral column, such as 
aquatic insects) species composition. Channelization may reduce the 
recruitment of fishes by eliminating nursery habitat through the 
removal of gradually sloping streambanks, reducing the extent of 
nearshore habitats with low water velocity (Scheidegger and Bain 1995, 
p. 125; M[eacute]rigoux and Ponton 1999, p. 177; Meng and Matern 2001, 
p. 750).
High-Intensity Wildfires
    Low-intensity fire has been a natural disturbance factor in 
forested landscapes for centuries, and low-intensity fires were common 
in southwestern forests and grasslands prior to European settlement 
(Rinne and Neary 1996, pp. 135-136). Rinne and Neary (1996, p. 143) 
discuss the current effects of fire management policies on aquatic 
communities in Madrean Oak Woodland biotic communities, a community 
type that comprises large portions of some watersheds occupied by 
roundtail chub. They concluded that existing wildfire suppression 
policies intended to protect the expanding number of human structures 
on forested public lands have altered the fuel loads in these 
ecosystems and increased the probability of devastating wildfires. 
Other researchers have also found that fire suppression policies in 
combination with other land uses have increased the probability of 
high-intensity fire due to past land use, fire suppression, and 
unnaturally high fuel loadings (Cooper 1960, pp. 161-162; Covington and 
Moore 1994, pp. 45-46; Swetnam and Baison 1994, pp. 12-13; Touchan et 
al. 1995, pp. 268-272; White 1985, p. 589). Not surprisingly, the 
intensity (size and severity) of forest fires has increased in recent 
times (Covington and Moore 1994, p. 40; Westerling et al. 2006, p. 
940).
    The effects of these catastrophic wildfires include the removal of 
vegetation, the degradation of watershed condition, altered stream 
behavior, and increased sediment and ash flows into streams. These 
effects can harm fish communities, as observed in the 1990 Dude Fire, 
when corresponding ash flows drastically reduced some fish populations 
in Dude Creek and the East Verde River (Voeltz 2002, p. 77). Fire has 
become an increasingly significant threat in lower-elevation 
communities as well. Esque and Schwalbe (2002, pp. 180-190) discuss the 
effect of wildfires in the upper and lower subdivisions of Sonoran 
desertscrub. The widespread invasion of nonnative annual grasses, such 
as brome (Bromus sp.) and Mediterranean grasses (Schismus sp.), appear 
to be largely responsible for altered fire regimes that have been 
observed in these communities, which are not adapted to fire (Esque and 
Schwalbe 2002, p. 165). African buffelgrass (Pennisetum ciliare) is 
recognized as another invading nonnative plant species throughout the 
lower elevations of northern Mexico and Arizona. Nijhuis (2007, pp. 1-
7) discusses the spread of nonnative buffelgrass within the Sonoran 
Desert of Arizona and adjoining Mexico, citing its ability to out-
compete native vegetation and present significant risks of fire in an 
ecosystem that is not adapted to fire. In areas comprised entirely of 
native plant species, ground vegetation density is mediated by barren 
spaces that do not allow fire to carry itself across the landscape. 
However, in areas where nonnative grasses have become established, the 
fine fuel load is continuous, and fire is capable of spreading quickly 
and efficiently (Esque and Schwalbe 2002, p. 175). These nonnative 
grasses thus increase the potential for catastrophic wildfire.
    After disturbances such as fire, nonnative grasses may exhibit 
dramatic population explosions, which hasten their effect on native 
vegetative communities. Additionally, with increased fire frequency, 
these population explosions ultimately lead to a type-conversion of the 
vegetative community from desertscrub to grassland (Esque and Schwalbe 
2002, pp. 175-176). Fires carried by the fine fuel loads created by 
nonnative grasses often burn at unnaturally high temperatures, which 
may result in soils becoming hydrophobic (water repelling), exacerbate 
sheet erosion, and contribute large amounts of sediment to receiving 
water bodies, thereby affecting the health of the riparian community 
(Esque and Schwalbe 2002, pp. 177- 178). The siltation of isolated, 
remnant pools in intermittent streams significantly affects lower-
elevation species by increasing the water temperature, reducing 
dissolved oxygen, and reducing or eliminating the permanency of pools, 
as observed in pools occupied by lowland leopard frogs (Rana 
yavapaiensis) and native fish (Esque and Schwalbe 2002, p. 190).
    Fires in the Southwest frequently occur during the summer monsoon 
season. As a result, fires are often followed by rain that washes ash-
laden debris into streams. Rinne (2004, p. 151) found significant 
reductions in fish abundance as a result of these ash flows,

[[Page 32368]]

with reductions in fish abundance ranging from 70 to 100 percent. 
Extreme summer fires, such as the 1990 Dude Fire, and corresponding ash 
flows, have drastically reduced some fish populations. Some recent 
examples of extreme summer fires that have reduced native fish 
populations include the 2002 Rodeo-Chedeski Fire, the 2003 Aspen Fire, 
and the 2004 Willow Fire, all of which burned parts of watersheds 
occupied by roundtail chub. Carter and Rinne (unpubl. data) found that 
the Picture Fire both benefited and eliminated headwater chub, a 
closely related species that occurs in similar habitat, from portions 
of Spring Creek. The fire eliminated chubs from Turkey Creek, a 
tributary to Spring Creek. In other parts of Spring Creek, however, 
chubs initially declined but later thrived after the fire, presumably 
because most of the nonnative fishes were eliminated.
    Dunham et al. (2003, pp. 189-190) examined how fire affects 
nonnative species invasions; although habitat alteration over time can 
facilitate nonnative species with wider habitat tolerances, native 
species may be better able to withstand ash flows and flooding. Thus 
immediately post-fire, nonnatives may be completely eliminated and the 
few natives present can take advantage of the reduction in predators. 
But such events, at a minimum, represent a genetic bottleneck (drastic 
reduction in population size) for the species that could adversely 
impact populations via genetic threats, such as inbreeding depression 
(reduced health due to elevated levels of inbreeding) and genetic drift 
(a reduction in gene flow within the species that can increase the 
probability of unhealthy traits) (Meffe and Carrol 1994, pp. 156-167). 
Many roundtail chub populations are fragmented and isolated. Fagan et 
al (2002, p. 3254) found that, as a result of this fragmentation and 
isolation, roundtail chub has moderately high risk of local 
extirpation. Dunham et al. (2003, pp. 188-189) found that the threat of 
fire to fish populations is much greater for highly fragmented and 
isolated populations of fishes.
Undocumented Immigration and International Border Enforcement and 
Management
    Cantrell (2009, p. 12) indicated that undocumented immigration and 
international border enforcement and management could be a threat in 
nine areas occupied by roundtail chub. Because the roundtail chub is 
extirpated from most of the southern portions of its range, such as the 
San Pedro River, this threat is more likely to affect potential 
recovery areas than currently occupied habitats, but is a possible 
threat in some occupied streams. Undocumented immigrants and smugglers 
attempt to cross the International border from Mexico into the United 
States in areas historically and currently occupied by the roundtail 
chub. These illegal border crossings and the corresponding efforts to 
enforce U.S. border laws and policies have been occurring for many 
decades with increasing intensity and have resulted in unintended 
adverse effects to biotic communities in the border region. During the 
warmest months of the year, many attempted border crossings occur in 
riparian areas that serve to provide shade, water, and cover. Increased 
U.S. border enforcement efforts that began in the early 1990s in 
California and Texas have resulted in a shift in crossing patterns and 
increasingly concentrated levels of attempted illegal border crossings 
into Arizona (Segee and Neeley 2006, p. 6).
    Traffic on new roads and trails from illegal border crossing and 
enforcement activities, as well as the construction, use, and 
maintenance of enforcement infrastructure (e.g., fences, walls, and 
lighting systems), leads to compaction of streamside soils, and the 
destruction and removal of riparian vegetation. Current border 
infrastructure projects, including vehicle barriers and pedestrian 
fences, are located specifically in valley bottoms and have resulted in 
direct impacts to water courses and altered drainage patterns (Service 
2008, p. 4). These activities also produce sediment in streams, which 
affects their suitability as habitat for roundtail chub by reducing 
their permanency and altering their physical and chemical parameters. 
Riparian areas along the upper San Pedro River have been impacted by 
abandoned fires that undocumented immigrants started to keep warm or 
prepare food (Segee and Neeley 2006, p. 23).
    Undocumented immigrants use wetlands for bathing, drinking, and 
other uses (Segee and Neeley 2006, pp. 21-22). These activities can 
contaminate the water quality of the wetlands and lead to reductions in 
habitat quality for roundtail chub (Rosen and Schwalbe 1988, p. 43; 
Segee and Neeley 2006, pp. 21-22). In addition, numerous observations 
of littering and destruction of vegetation and wildlife occur annually 
throughout the border region, which can adversely affect the quality of 
habitat for the roundtail chub (Service 2006, p. 95).
Conservation Actions Relevant to Factor A
    There are several existing conservation agreements for native fish 
species that include roundtail chub (discussed in detail in Factor E 
below): the Utah Department of Natural Resources' ``Range-wide 
conservation agreement and strategy for roundtail chub (Gila robusta), 
bluehead sucker (Catostomus discobolus), and flannelmouth sucker 
(Catostomus latipinnis)'' (Range-wide Agreement; Utah Department of 
Natural Resources 2002); the New Mexico Department of Game and Fish's 
(NMDGF) ``Colorado River Basin Chubs Recovery Plan'' (New Mexico Plan; 
Carman 2006), which includes the headwater and Gila chubs; and the 
AGFD's ``Arizona Statewide Conservation Agreement for Roundtail Chub 
(Gila robusta), Headwater Chub (Gila nigra), Flannelmouth Sucker 
(Catostomus latipinnis), Little Colorado River Sucker (Catostomus 
spp.), Bluehead Sucker (Catostomus discobolus), and Zuni Bluehead 
Sucker (Catostomus discobolus yarrowi)'' (Arizona Agreement; AGFD 
2006).
    The Range-wide Agreement, Arizona Agreement, and New Mexico Plan 
all include actions intended to reduce the threat of habitat loss. The 
Range-wide Agreement recommends enhancing and maintaining habitat for 
roundtail chub, including: Enhance and/or restore connectedness and 
opportunities for migration of the subject species to disjunct 
populations where possible; restore altered channel and habitat 
features to suitable conditions; provide flows needed for all life 
stages; maintain and evaluate fish habitat improvements; and install 
regulatory mechanisms for the long-term protection of habitat (e.g., 
conservation easements, water rights). The Arizona Agreement identifies 
the need to secure, enhance, and create habitat as one of its 
conservation strategy tasks and includes these subtasks:
    (1) Maintain instream flow;
    (2) Manage detrimental nonnative fish and other aquatic species;
    (3) Evaluate effectiveness of nonnative management efforts;
    (4) Restore natural fire regimes;
    (5) Manage the spread of infectious diseases and parasites to 
habitats of the subject species;
    (6) Enhance and/or restore connectedness;
    (7) Develop appropriate flow recommendations for areas where 
existing flow regimes are inadequate;
    (8) Implement flow recommendations;
    (9) Restore altered channel and habitat features;

[[Page 32369]]

    (10) Create, maintain, and evaluate fish refugia throughout 
historic range; and
    (11) Maintain habitat quality.
    The New Mexico Plan identifies the need to address habitat loss, 
including:
    (1) Identify and determine habitat requirements for all life 
history stages of roundtail chub in the San Juan and Gila River basins;
    (2) Support efforts within existing programs to enable habitat 
restoration and protection for recovery;
    (3) Identify and secure resources to promote habitat restoration 
and protection;
    (4) Rehabilitate, restore, and secure historical habitats where 
chub restoration is possible;
    (5) Inform private and public landowners about practices that 
promote diverse, functional aquatic and riparian habitats;
    (6) Inform private and public landowners about how to protect chub 
habitat;
    (7) Identify and secure funding to promote habitat restoration and 
protection; and
    (8) Establish formal agreements with willing participants to 
enhance habitat and/or populations for recovery of roundtail chub.
    Several actions are planned or have been implemented as a result of 
the conservation agreements that address the threat of habitat loss. 
They are discussed below.
    The Nature Conservancy (Conservancy) is a signatory to the Arizona 
Agreement. In Arizona, the Conservancy has launched its Nature Matters 
fundraising campaign. This program raises private donations to support 
cooperative land and water protection projects. The Conservancy 
contacts landowners to explore their interest in placing their property 
in a permanently protected status, then works cooperatively with its 
agency partners to negotiate purchase and sale agreements and to 
develop fundraising proposals and project financing. Properties are 
identified and prioritized based on the quality of their riparian and 
aquatic habitat as well as opportunities to secure surface water rights 
or to file for new water rights to maintain instream flow.
    In 2007, the Conservancy purchased the Upper Verde River Wildlife 
Area, a 313-acre (ac) (127-hectare (ha)) parcel downstream from the 
Verde River confluence with Granite Creek near Paulden, Arizona. The 
Conservancy later received the donation of an additional 160 ac (65 
ha). In total, the acquisition secured the largest remaining portion of 
the Verde River headwaters still in private ownership and protects 
roughly 1 mi (1.6 km) of high quality riparian and aquatic habitat from 
development and improper livestock grazing. In 2008, the Conservancy 
conveyed 293 ac (119 ha) of this property to the AGFD to be added to 
the Upper Verde River Wildlife Area. In July of 2008, the Conservancy 
and AGFD each filed for instream flow water rights with the Arizona 
Department of Water Resources for the properties.
    In 2008, the Conservancy completed two land acquisitions on the 
middle Verde River within the 33-mi (53-km) stretch that Arizona State 
Parks has designated for acquisition as the Verde River Greenway: a 20-
ac (8-ha) parcel upstream of Camp Verde that is adjacent to U.S. Forest 
Service frontage on the river; and the 209-ac (85-ha) Rockin' River 
Ranch property purchased with Arizona State Parks. The Rockin' River 
property, located at the confluence of the Verde River and West Clear 
Creek, includes 55 ac (22 ha) under irrigation with surface water 
rights dating back to 1889. Protection of the property provides an 
opportunity to retire and dedicate water rights to instream flow for 
the benefit of wildlife including roundtail chub. The Conservancy 
continues to meet with landowners on a willing-seller basis to explore 
opportunities to protect additional lands along the river and in the 
Big Chino Valley, which overlays the aquifer that is the primary 
groundwater source for the upper Verde River, and to pursue private and 
public funding to support land and water protection in the Verde 
watershed. These actions could help secure instream flow and protect 
riparian areas from harmful land uses, benefitting roundtail chub.
    In 2006, the Conservancy received as a donation the Cobra Ranch 
property at the headwaters of Aravaipa Creek near Klondyke, Arizona. 
The addition of this property to the Conservancy's Aravaipa Canyon 
Preserve protects over 1 mi (1.6 km) of stream channel and presents 
significant habitat restoration opportunities. The Conservancy plans to 
restore native vegetation on 100 ac (40 ha) of farm ground, and retire 
irrigation, which will reduce draw-down of the aquifer and create 
improved infiltration patterns on the farm. They will also 
strategically plant native vegetation along the active channel to 
restore the natural river channel. Fencing is being installed to remove 
grazing from riparian areas, and planning is ongoing to restore a 
natural fire regime. These actions will serve to restore a historical 
cienega that once existed in the headwaters of Aravaipa Creek, and will 
reduce overgrazing, dewatering, and sedimentation effects to the 
roundtail chub in Aravaipa Creek.
    The U.S. Forest Service is also a signatory to the Arizona 
Agreement. The Tonto National Forest is working to establish an 
instream flow water right on approximately 36 mi (58 km) of U.S. Forest 
Service lands along Cherry Creek from its headwaters to the confluence 
with the Salt River. Once in place, the water right should protect 
enough flow to provide for roundtail chub habitat in perpetuity. 
Similarly, through the Horseshoe and Bartlett Habitat Conservation 
Plan, Salt River Project (SRP), a large water and electricity provider 
for portions of Arizona, is implementing watershed management efforts 
to maintain or improve stream flows in the Verde River, including 
funding of stream gages and scientific studies, in-kind support for 
watershed improvements, and administrative and legal efforts to curtail 
stream flow reductions from illegal surface water diversions and 
groundwater pumping.
    The Arizona Agreement also includes provisions for addressing the 
threat of catastrophic wildfire. A conservation strategy task is to 
restore natural fire regimes in the watersheds of extant populations of 
roundtail chub, including securing habitat through the use of 
prescribed fire and noncommercial understory thinning to restore 
natural fire regimes. Controlled prescribed fires reduce the risk of 
catastrophic wild fires by reducing fuel loads. The New Mexico Plan 
also identifies the need to support research to determine the tolerance 
of roundtail chub to water quality parameters, particularly those that 
may be altered during and after forest fires.
Summary of Factor A
    Rivers, streams, and riparian habitats that are essential for the 
survival of the roundtail chub are being adversely affected and 
eliminated throughout the range of the species. Threats, including 
water diversions, groundwater pumping, dams, channelization, and 
erosion-related effects, are occurring that impact both the amount of 
water available for habitat, as well as the water's suitability for 
roundtail chub. Threats from flood control, development, roads, water 
withdrawal, improper livestock grazing, recreation, and high-intensity 
wildfire dry up, silt in, physically alter, and chemically pollute 
habitats of the roundtail chub such that habitats become permanently 
unsuitable. These threats have been documented historically and are 
either occurring or likely to occur throughout the range of the 
roundtail chub. These

[[Page 32370]]

threats reduce the habitat's suitability as cover for protection from 
predators, as a foraging area, and as spawning and nursery areas. 
Despite the conservation actions discussed above, the dewatering of 
aquatic habitats in the arid lower Colorado River basin poses a 
significant threat to all native fish of the region, including 
roundtail chub. All of these threats are anthropogenic and can be 
expected to continue, if not increase, given the predictions for 
increases in human population expansion in the region. Efforts to 
ameliorate these threats through established conservation agreements 
have met with some success, but are in the early stages of 
implementation.

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

    Overutilization of roundtail chub for commercial, recreational, 
scientific, or educational purposes is not considered a significant 
threat to the roundtail chub in the lower Colorado River basin. 
Roundtail chub is a permitted sport fish in Arizona (AGFD 2008). One 
roundtail chub greater than 13 in. (33 cm) is allowed via angling per 
day. The AGFD has also established a catch-and-release only, artificial 
fly and lure only, single barbless hook, 7-month fishing season for 
roundtail chub in Fossil Creek. A 4.5-mi (7.2-km) middle reach segment 
of Fossil Creek will be open to catch-and-release fishing for roundtail 
chub from Oct 3, 2009, through April 30, 2010. The remainder of the 
year, the area is closed to all fishing. But angler use of roundtail 
chub is light (C. Cantrell, AGFD, pers. comm. 2009), and we do not 
believe that overutilization from current levels of angling is a threat 
to the species in Arizona. In the upper Gila River in New Mexico, where 
the species is not a legal sport fish (NMDGF 2008), there are reports 
of anglers purposefully discarding chub species, which may be having a 
negative effect on populations of roundtail chub locally (Voeltz 2002).
    Several studies of fish species closely related to roundtail chub 
indicate that handling for scientific purposes (research and 
monitoring) may have some adverse effects on individual fish. Ruppert 
and Muth (1997, p. 314) found that electrofishing caused spinal 
hemorrhages in some juvenile humpback chub (Gila cypha), a closely 
related species to roundtail chub, but did not affect short-term growth 
or survival. Paukert et al. (2005, p. 649) found that use of hoop nets 
affected fish growth and condition of bonytail; fish captured multiple 
times grew less in length and weight than fish not recaptured. Fish 
recaptured up to five times grew only 12.8 percent of their initial 
weight compared to fish not recaptured, which grew 29.7 percent of 
their initial weight. Ward et al. (in press) also found some mortality 
from use of passive integrated transponder tags in related Gila chub 
(G. intermedia) and bonytail, although mortality rate was low. We 
believe the level of handling of roundtail chubs for scientific 
purposes is low, and the results of these studies suggest that handling 
roundtail chubs for scientific purposes is not a significant threat to 
the species.
Conservation Actions Relevant to Factor B
    Overutilization of roundtail chub is not believed to be a threat to 
the species and is therefore not addressed in conservation planning 
efforts. All three conservation agreements include action items to 
identify threats; thus, if there is some unidentified threat from 
overutilization or the degree of the threat has been underestimated, 
the conservation agreements should serve to help identify this in the 
future.
Summary of Factor B
    Although roundtail chub is a legal sport fish in Arizona, available 
information indicates that the species is not threatened by 
overutilization as a game species from current levels of angling. There 
is some information that collection for scientific purposes has some 
adverse effects on individual fish; however, we do not believe that 
handling roundtail chubs for scientific purposes is a significant 
threat to the species.

Factor C. Disease or Predation

Nonnative Species
    Nonnative species that compete with or prey on roundtail chub are a 
serious and persistent threat to the continued existence of the 
roundtail chub. Nonnative aquatic species include fishes, aquatic and 
semi-aquatic mammals, reptiles, amphibians, crustaceans, mollusks 
(snails and clams), insects, zooplankton, phytoplankton, parasites, 
disease organisms, algae, and aquatic and riparian vascular plants. The 
introduction and spread of nonnative species has long been identified 
as one of the major factors in the continuing decline of native fishes 
throughout North America and particularly in the Southwest (Miller 
1961, p. 365; Lachner et al. 1970, pp. 1-4; Ono et al. 1983, p. 90; 
Minckley and Deacon 1991; Carlson and Muth 1989, p. 220; Cohen and 
Carlton 1995, p.1; Fuller et al. 1999, pp. 1-3; Clarkson et al. 2005, 
p. 20; Mueller 2005, pp. 10-12; Olden and Poff 2005, p. 75). Nonnative 
species may affect native fish and other aquatic fauna through numerous 
means, including (all of which may be applicable to the roundtail 
chub): Predation (Meffe et al. 1983, p. 316; Meffe 1985, p. 173; Marsh 
and Brooks 1989, p. 188; Propst et al. 1992, p. 177; Blinn et al. 1993, 
p. 139; Rosen et al. 1995, p. 251), competition (Lydeard and Belk 1993, 
p. 370; Baltz and Moyle 1993, p. 246; Scoppotone 1993, p. 139; Douglas 
et al. 1994, pp. 15-17), aggression (Meffe 1984, p. 1525; Karp and Tyus 
1990, p. 25), habitat disruption (Hurlbert et al. 1972, p. 639; 
Fernandez and Rosen 1996, p. 3), introduction of diseases and parasites 
(Clarkson et al. 1997, p. 66; Robinson et al. 1998, p. 599), and 
hybridization (Dowling and Childs 1992, p. 355; Echelle and Echelle 
1997, p. 153). Because the impacts of competition with and predation by 
nonnative species are often interrelated and difficult to discuss 
separately, we will discuss all impacts of nonnative species in this 
section.
    In an evolutionary context, the native fish community of the lower 
Colorado River basin, including roundtail chub, evolved with low 
species diversity and with few predators and competitors and thus co-
evolved with few predatory fish species. In contrast, many of the 
nonnative species co-evolved with high species diversity and many 
predatory species (Clarkson et al. 2005, p. 21). A contributing factor 
to the decline of native fish species cited by Clarkson et al. (2005, 
p. 21) is that most of the nonnative species evolved behaviors, such as 
nest guarding, to protect their offspring from these many predators, 
while native species are generally broadcast spawners that provide no 
parental care. In the presence of nonnative species, the reproductive 
behaviors of native fish fail to allow them to compete effectively with 
the nonnative species, and, as a result, the viability of native fish 
populations is reduced.
    In the Southwest, Miller et al. (1989, p. 22) concluded that 
introduced nonnatives were a causal factor in 68 percent of the fish 
extinctions in North America in the last 100 years. For 70 percent of 
those fish still extant, but considered to be endangered or threatened, 
introduced nonnative species are a primary cause of the decline 
(Aquatic Nuisance Species Task Force 1994; Lassuy 1995, p. 391). The 
widespread decline of native fish species from the arid southwestern 
United States and Mexico from interactions with nonnative species has

[[Page 32371]]

been manifested in the listing rules of nine native species listed 
under the Act whose historical ranges overlap with the historical and 
current distribution of the roundtail chub: Bonytail (Gila elegans) (45 
FR 27710; April 23, 1980), humpback chub (Gila cypha) (32 FR 4001; 
March 11, 1967), Gila chub (Gila intermedia) (70 FR 66663; November 2, 
2005), Colorado pikeminnow (Ptychocheilus lucius) (32 FR 4001; March 
11, 1967), spikedace (Meda fulgida) (51 FR 23769; July 1, 1986), loach 
minnow (Tiaroga cobitis) (51 FR 39468; October 28, 1986), razorback 
sucker (Xyrauchen texanus) (56 FR 54957; October 23, 1991), desert 
pupfish (Cyprinodon macularius) (51 FR 10842; March 31, 1986), and Gila 
topminnow (Poeciliopsis occidentalis) (32 FR 4001; March 11, 1967). In 
total within Arizona, 19 of 31 (61 percent) native fish species are 
listed under the Act. Arizona ranks the highest of all 50 States in the 
percentage of native fish species with declining trends (85.7 percent, 
Stein 2002, p. 21; Warren and Burr 1994, pp. 6-18). In the Gila River 
basin, introduction of nonnatives is considered a major factor in the 
decline of all native fish species (Miller 1961, pp. 377-379; Williams 
et al. 1985, p. 1; Minckley and Deacon 1991). In Arizona, release or 
dispersal of new nonnative aquatic organisms is a continuing phenomenon 
(Rosen et al. 1995, p. 259; Service 2008, p. 264).
    Aquatic nonnative species are introduced and spread into new areas 
through a variety of mechanisms, both intentional and accidental, and 
authorized and unauthorized. Mechanisms for nonnative dispersal in the 
southwestern United States include inter-basin water transfer (Service 
2008, p. 1), sport fish stocking (Clarkson et al. 2005, p. 20), 
aquaculture and aquarium releases (Courtenay 1993, pp. 35-62; Crossman 
1991, p. 46; Crossman and Cudmore 2000, pp. 129-134; Mackie 2000, pp. 
135-150), bait-bucket release (release of fish used as bait by anglers) 
(Crossman 1991, p. 50; Litvak and Mandrak 1993, p. 6), and to control 
other species (such as the introduction of herbivorous fish to control 
aquatic plants) (Bailey 1978, p. 181; Courtney 1993, p. 37).
    In the Verde River system alone, Rinne et al. (1998, p. 3) 
estimated that over 5,300 independent stocking actions occurred that 
involved 12 different species of nonnative fish species since the 1930s 
and 1940s. If we extrapolate that effort over the same timeframe for 
other historically occupied, larger-order systems known as recreational 
fisheries (such as the Salt, upper Gila, Bill Williams, and San Pedro 
Rivers, and Oak Creek and other tributaries with significant flow 
throughout central and southern Arizona), in addition to the other 
private stockings of stock tanks and other isolated habitat, the 
magnitude of the nonnative species invasion over this timeframe becomes 
clear. Subsequent to these efforts, but to a lesser extent, the spread 
of bullfrogs and crayfish, both purposefully and incidentally, 
commenced during the 1970s and 1980s (Tellman 2002, p. 43). We estimate 
that nearly 100 percent of the habitat that historically supported 
roundtail chub has been invaded over time, either purposefully or 
indirectly through dispersal, by nonnative fishes and other aquatic 
species.
    Nonnative fishes known from within the historical range of 
roundtail chub in the lower Colorado River basin include channel 
catfish (Ictalurus punctatus), flathead catfish (Pylodictis olivaris), 
red shiner (Cyprinella lutrensis), fathead minnow (Pimephales 
promelas), green sunfish (Lepomis cyanellus), warmouth (L. gulosus), 
bluegill (L. macrochiris), largemouth bass (Micropterus salmoides), 
smallmouth bass (M. dolomieui), rainbow trout (Oncorynchus mykiss), 
western mosquitofish (Gambusia affinis), carp (Cyprinus carpo), yellow 
bullhead (Ameiurus natalis), black bullhead (A. melas), and goldfish 
(Carassius auratus) (Bestgen and Propst 1989, pp. 409-410; Marsh and 
Minckley 1990, p. 265; Sublette et al. 1990, pp. 112, 243, 246, 304, 
313, 318; Abarca and Weedman 1993, pp. 6-12; Stefferud and Stefferud 
1994, p. 364; Weedman and Young 1997, p. 1, Appendices B, C; Rinne et 
al. 1998, pp. 3-6; Voeltz 2002, p. 88; Bonar et al. 2004, pp. 1-108; 
Fagan et al. 2005, pp. 34, 38-39, 41). The fastest expanding nonnative 
species are red shiner, fathead minnow, green sunfish, largemouth bass, 
western mosquitofish, and channel catfish. These species are considered 
to be the most invasive in terms of their negative impacts on native 
fish communities (Olden and Poff 2005, p. 75).
    Smaller size classes (juvenile and subadult fish) are more 
vulnerable to predation because the size of a fish that a predatory 
fish can consume is limited by the predator's gape size. Brouder et al. 
(2000, p. 13) found that size class of native fishes consumed 
(including roundtail chub) by predatory nonnative fishes in the Verde 
River was 1.3 to 3.5 in (34 to 90 millimeters (mm)). This winnowing 
effect results in a population of only large adult fish, which 
eventually crashes. A spectacular example of this is the case of the 
razorback sucker in Lake Mohave in Arizona and Nevada. For decades, no 
recruitment was documented within the population, although large adults 
(razorback sucker is a large species, with adults up to 20 in. (500 mm) 
or longer in total length) remained common. This situation was possible 
because razorback sucker are very long-lived, living 40 years or more 
(McCarthy and Minckley 1987, p. 87). The population eventually crashed 
in the 1990s because of a total lack of recruitment due to predation by 
nonnative fish species on smaller, younger fish, although conservation 
efforts have resulted in maintenance of a much smaller stocked 
population (Service 2002a, pp. 9, 11; Mueller 2005, p. 11). A similar 
population crash likely happened to bonytail, a species closely related 
to roundtail chub, in Lake Mohave, with the crash happening sooner 
because bonytail likely have a shorter life span (Service 2002b, p. 11, 
A-6).
    The introduction of more aggressive and competitive nonnative fish 
has likely led to losses of roundtail chub (Voeltz 2002, p. 88). Dudley 
and Matter (2000, p. 24) found that nonnative green sunfish prey on, 
compete with, and virtually eliminate recruitment of Gila chub (a 
closely related species to roundtail chub) in Sabino Creek in Arizona. 
Similar effects of green sunfish on Gila chub have been documented in 
Silver Creek in Arizona (Unmack et al. 2004, pp. 86-87), with 
recruitment of Gila chub effectively eliminated by nonnative green 
sunfish. In the Verde River mainstem, Bonar et al. (2004, p. 57) found 
that nonnative fishes were approximately 2.6 times more dense per unit 
volume of river than native fishes, and their populations were 
approximately 2.8 times that of native fishes per unit volume of river. 
Bonar et al. (2004, pp. 6-7) found that largemouth bass, smallmouth 
bass, bluegill, green sunfish, channel catfish, flathead catfish, and 
yellow bullhead all consumed native fish; although roundtail chub was 
not detected in the diet of any nonnative fishes, this is likely only 
due to the relative rarity of the species compared with other native 
fish, as well as the short time necessary for a fish to be digested. 
Roundtail chubs have been found in stomachs of largemouth bass in the 
lower Salt River (P. Unmack, Arizona State University, pers. comm. 
2008). Bestgen and Propst (1989, p. 406) reported that, of nonnatives 
present in New Mexico, smallmouth bass, flathead catfish, and channel 
catfish most impacted roundtail chub via predation. Native fishes, 
including roundtail chub, have experienced significant declines in the 
Salt River above Roosevelt Lake,

[[Page 32372]]

concurrent with a significant increase in flathead and channel catfish 
numbers (Creef and Clarkson 1992, p. 5; Jahrke and Clark 1999 p. 9). 
Brouder et al. (2000, p. 9), based on population estimates, determined 
that nonnative species were likely suppressing roundtail chub 
populations in two areas of the upper Verde River. Yard et al. (2008) 
found that rainbow trout predation on humpback chub in Grand Canyon 
likely resulted in significant levels of humpback chub mortality (Yard 
et al. 2008, p. 53).
    In some areas, the presence of nonnative species appears to be 
limiting recruitment of roundtail chub, with only large adults 
encountered during surveys (Cantrell 2009, p. 10). Red shiner is known 
to compete with native southwestern cyprinids (Minckley and Deacon 
1968, pp. 1427-1428; Minckley 1973, p. 138; Douglas et al. 1994, p. 9), 
and prey on larval fishes (Ruppert et al. 1993, p. 397). In a study of 
the roundtail chub population in the lower Salt and Verde Rivers, Bryan 
and Hyatt (2004, p. 3) estimated adult population size of roundtail 
chub to be 1,657, and found that this was a 74 percent decrease from 
just 3 years earlier. Bryan and Hyatt (2004, pp. 12-13) concluded that 
the roundtail chub population in the lower Salt and Verde Rivers was 
declining rapidly due to low recruitment and high natural mortality, 
and identified the ``negative impacts of competition and predation 
[from the] introduction of nonnative fishes into roundtail chub 
habitat'' as the likely cause of recruitment failure. They recommended 
that stocking nonnative sport fish ``be carefully evaluated and 
probably suspended, especially with regards to predatory species'' and 
that stocking rainbow trout ``be thoroughly evaluated to determine its 
economic impact and the specific impacts to the [roundtail] chub 
population.''
    Few if any studies of roundtail chub have effectively demonstrated 
competition with nonnative fishes, although numerous authors have 
considered it a threat (Bestgen and Propst 1989; Brouder et al. 2000; 
Voeltz 2002; AGFD 2006, p. 5). Bestgen (1985, p. 53) found that diets 
between rainbow trout and roundtail chub differed to an extent that 
suggested interactive segregation of habitat and competition for food 
resources, and although the health of the chub population indicated 
competition was not severe, in higher densities, trout competition 
could impact roundtail chub. Dudley and Matter (2000, p. 24) found that 
green sunfish utilized the same habitats as Gila chub, a closely 
related species to roundtail chub, and appeared to competitively 
exclude them from preferred habitats. In the Colorado River in Grand 
Canyon, Arizona, diet studies of humpback chub and rainbow trout show 
strong overlap for aquatic invertebrates such as blackfly larvae 
(Simuliidae) and Gammarus (Valdez and Ryel 1995; Yard et al. 2008), and 
removal of nonnative trout is one factor suspected to be responsible 
for a recent increase in humpback chub numbers in Grand Canyon (U.S. 
Geological Survey 2006, p. 2). But because rainbow and brown trout 
(Salmo trutta) have also been shown to prey on humpback chub in the 
Grand Canyon (Yard et al. 2008), either a reduction in predation of 
humpback chub, or a reduction in competition with humpback chub, or 
both, may be responsible. Intuitively, both scenarios seem likely, and 
this is the conventional wisdom of many researchers studying the 
effects of nonnative fishes on natives in the southwest United States 
(Marsh and Douglas 1997; Brouder et al. 2000; Voeltz et al. 2002; AGFD 
2006, p. 5). Interestingly, Bestgen (1985, p. 53) noted that any 
competition between rainbow trout and roundtail chub would likely be 
significant only if rainbow trout occurred in high densities, and in 
Grand Canyon, high densities of rainbow trout appear to be impacting 
the humpback chub population (Yard et al. 2008; U.S. Geological Survey 
2006). Marks et al. (in press) found that when nonnative fish species 
were removed, roundtail chub numbers and recruitment increased 
dramatically. Again, whether this is because nonnative species were 
preying on or competing with roundtail chub is still a question, but 
perhaps one that is not necessary to answer, for as Marks et al. (2008) 
illustrate, the remedy for this threat is obvious.
    Aquatic habitat alterations due to land use practices such as 
livestock grazing and dams and dam operation may facilitate the spread 
and persistence of nonnative fishes. Dams by their very purpose and 
nature serve to reduce flood flows and increase base flows. Floods have 
been identified as a potential means to disadvantage nonnative fishes 
and thereby advantage native fishes (Meffe 1984, p. 1525). Haney et al. 
(2008, p. 61) suggested that diminished river flow due to diversion may 
be an important factor in loss of native fish from the Verde River. 
Variation in river flows may provide both advantages and disadvantages 
to aquatic species. The timing, duration, intensity, and frequency of 
flood events has been altered to varying degrees by the presence of 
dams along many stream courses within the range of the roundtail chub, 
which affects fish communities. Flood pulses may help to reduce 
populations of nonnative species because, unlike native fish that are 
adapted to dramatic fluctuations in water conditions and flow regimes 
(including random high-intensity events, such as flooding, extreme 
water temperatures, and excessive turbidity), nonnative fishes appear 
to be less well-adapted to such events. Dams, through their 
amelioration of flood flows and increased base flows, may provide more 
suitable habitat for nonnative fishes (Meffe 1984, p. 1525; Haney et 
al. 2008, p. 61).
    Livestock tanks also may facilitate the persistence and spread of 
nonnative species of fish, amphibians, and crayfish that are 
intentionally or unintentionally stocked by anglers and private 
landowners (Rosen et al. 2001, p. 24). The management of stock tanks is 
an important consideration for native fish restoration. Stock tanks 
associated with livestock grazing can be intermediary ``stepping 
stones'' in the dispersal of nonnative species from larger source 
populations to new areas, and serve as source populations themselves 
(Rosen et al. 2001, p. 24; Stone et al. 2007, p. 133).
    Recent assessments of the fish fauna of the lower Colorado River 
basin have provided additional insight into the importance of nonnative 
fishes as a threat to native fish including the roundtail chub. The 
Desert Fishes Team is an ``independent group of biologists and parties 
interested in protecting and conserving native fishes of the Colorado 
River basin'' and includes personnel from the U.S. Forest Service, U.S. 
Bureau of Reclamation, Bureau of Land Management (BLM), University of 
Arizona, Arizona State University, the Conservancy, and independent 
experts (Desert Fishes Team 2003, p. 1). Desert Fishes Team (2003, p. 
1) declared the native fish fauna of the Gila River basin to be 
critically imperiled, citing habitat destruction and nonnative species 
as the primary factors for the declines. The Desert Fishes Team 
recommended control and removal of nonnative fish as an overriding need 
to prevent the decline and ultimate extinction of native fish species 
within the basin. Clarkson et al. (2005) discuss management conflicts 
as a primary factor in the decline of native fish species in the 
southwestern United States and declare the entire native fauna as 
imperiled. The investigators cite nonnative species as the most 
consequential factor leading to range-wide declines that prevent or 
negate recovery efforts from being implemented or being successful

[[Page 32373]]

(Clarkson et al. 2005, p. 20). Clarkson et al. (2005, p. 20) note that 
over 50 nonnative species have been introduced into the Southwest as 
either sport fish or bait fish and are still being actively stocked, 
managed for, and promoted by both Federal and State agencies as 
nonnative recreational fisheries. To help resolve the conflicting 
management mandates of native fish recovery and the promotion of 
recreational fisheries, Clarkson et al. (2005, pp. 22-25) propose the 
designation of entire watersheds as having either native or nonnative 
fisheries and the management of watersheds to aggressively meet these 
goals. Clarkson et al. (2005, p. 25) suggest that current management of 
fisheries within the southwestern United States as status quo will have 
serious adverse effects on native fish species and affect the long-term 
viability of these species.
    Mash and Pacey (2005, p. 59) concluded, ``The presence of nonnative 
fishes alone precludes life-cycle completion by the natives. In the 
absence of nonnatives, however, the natives thrive even in severely 
altered habitats.'' This statement appears to apply well to roundtail 
chub, and the best evidence is provided by the response of the species 
when nonnative fishes are removed. Marks et al. (in press) examined the 
effect of the removal of nonnative species on native species by 
measuring fish abundance before and after a restoration project to 
restore flow and chemically remove nonnative fishes (using the chemical 
rotenone, a fish pesticide) to benefit native fish species including 
the roundtail chub. They found that roundtail chub abundance increased 
dramatically after restoration, and attributed most of this response to 
the removal of nonnative fish species. Marks et al. (in press) 
suggested that nonnative fish removal may be a more cost effective 
method to restore native fish populations than flow restoration, 
because the cost of chemical renovation was one-tenth the cost of flow 
restoration at Fossil Creek. Roundtail chub is a stream species that 
appears to require flow (Service 1987; Marks et al. in press). However, 
AGFD has found that roundtail chub can thrive in pond habitats that are 
free from nonnative species (AGFD 2009). Similarly, Mueller (2008, p. 
2) examined the creation and performance of various nonnative fish-free 
habitats for bonytail chub, a species closely related to the roundtail 
chub, and found that recruitment occurred in hatchery-style holding 
ponds, seemingly a less than optimal habitat for a species that occurs 
in large rivers. Mueller (2008) concluded, ``In all cases, the common 
denominator was not physical habitat conditions; it was simply the 
absence of nonnative predators.'' As these findings illustrate, habitat 
may not be the biggest concern for roundtail chub because the species 
can thrive even in habitats that are seemingly less than ideal, as long 
as nonnative species are not present. Despite some lack of direct 
evidence of the effect of predation and recruitment on roundtail chub, 
the results of removal of nonnative fish clearly demonstrate that 
either predation or competition is occurring and is a serious threat to 
the species.
    Nonnative species predation may be having an effect on roundtail 
chub that is known as the ``predator pit'' hypothesis (Messier 1994, p. 
480). This hypothesis proposes that as a population of a species 
decreases, especially when this happens rapidly, the predators of the 
species will have an increasing impact on its survival due to the 
relatively constant consumption amount, and thus increased consumption 
rate. In situations where predator populations also increase, the 
effect can be substantial. Given the variety of habitat-altering 
activities that appear to be affecting roundtail chub throughout the 
lower Colorado River basin, activities such as dewatering and 
urbanization are likely reducing roundtail populations. With these 
reductions, predation by nonnative species create a ``predator pit'' 
scenario.
    At least two species of crayfish, the red swamp crayfish 
(Procambaris clarki) and the northern or virile crayfish (Orconectes 
virilis), have been introduced into Arizona aquatic ecosystems and are 
now widely distributed and locally abundant in a broad array of natural 
and artificial free-flowing and still-water habitats throughout the 
State, including numerous streams within the historical and current 
range of the roundtail chub (Inman et al. 1998, p. 3; Voeltz 2002, pp. 
15-88). Crayfish appear to negatively impact native fishes and aquatic 
habitats through habitat alteration by burrowing into stream banks and 
removing aquatic vegetation, resulting in decreases in vegetative cover 
and increases in turbidity (Lodge et al. 1994, p. 1270; Fernandez and 
Rosen 1996, pp. 10-12). Carpenter (2005, pp. 338-340) documented that 
crayfish may reduce the growth rates of native fish through competition 
for food and noted that the significance of this impact may vary 
between species. Crayfish also prey on fish eggs and larvae (Inman et 
al. 1998, p. 17). Crayfish alter the abundance and structure of aquatic 
vegetation by grazing on aquatic and semiaquatic vegetation, which 
reduces the cover for fish (Fernandez and Rosen 1996, pp. 10-12). Creed 
(1994, p. 2098) found that filamentous alga (Cladophora glomerata) was 
at least 10-fold greater in aquatic habitat absent crayfish. 
Filamentous alga is an important component of aquatic vegetation that 
provides cover and food for fish, including roundtail chub.
Diseases and Parasites
    Diseases, specifically parasite infestations, are a threat to the 
roundtail chub. Asian tapeworm (Bothriocephalus acheilognathi) was 
introduced into the United States via imported grass carp 
(Ctenopharyngodon idella) in the early 1970s. Asian tapeworm has since 
become well-established in the Southeast and mid-South and has been 
recently found in the Southwest. The definitive host in the life cycle 
of B. acheilognathi is cyprinid fishes, and, therefore, it is a 
potential threat to the roundtail chub as well as to the other native 
fishes in Arizona. The Asian tapeworm affects fish health in several 
ways. Two direct impacts are by (1) impeding the digestion of food as 
it passes through the intestinal track, and (2) causing emaciation and 
starvation when large numbers of worms feed off of the fish. The Asian 
tapeworm is present in the Colorado River basin in the Virgin River 
(Heckman et al. 1986, p. 662) and the Little Colorado River (Clarkson 
et al. 1997, p. 66). It has recently invaded the Gila River basin and 
was found in 1998 in the Gila River near Ashurst-Hayden Dam. Research 
and monitoring of the effects of Asian tapeworm on a related species, 
the humpback chub, indicate that this parasite may be a significant 
cause of mortality because large numbers of Asian tapeworm have been 
detected in wild humpback chub, and laboratory studies indicate that 
such infestations cause mortality in Gila species (U.S. Geological 
Survey 2004, p. 1; 2005, pp. 2-3).
    Anchor worm (Lernaea cyprinacea, Copepoda), an external parasite, 
is unusual in that it has little host specificity, infecting a wide 
range of fishes and amphibians. Severe Lernaea sp. infections have been 
noted in a number of chub populations. Infections of Lernaea sp. may 
have increased in recent years. James (1968, pp. 21-29) found that 
Lernaea sp. was very rare in museum specimens collected prior to the 
1930s, but increased in intensity from the 1930s to the 1960s, with 
roundtail chubs exhibiting the greatest increase (10.8 percent). 
Hendrickson (1993, pp. 45-46) noted very high infections of Lernaea sp. 
during warm

[[Page 32374]]

periods in the Verde River, and Voeltz (2002, p. 69) reported that 
headwater chubs found in Gun Creek in 2000, when surface flow was 
almost totally lacking, ``showed signs of stress, and many had Lernaea, 
black grub, lesions and an unidentified fungus.'' Girmendonk and Young 
(1997, p. 55) concluded that ``parasitic infestations may greatly 
affect the health and thus population size of native fishes.'' A die-
off of fish including roundtail chub in Trout Creek was likely due to 
heavy infestations of black grub (Neascus sp.), an internal parasite, 
which may have weakened the fish sufficiently to cause bacteria 
hemorrhagic septicemia or blood poisoning (Voeltz 2002, p. 33).
    The parasite Ichthyophthirius multifiliis, or ``Ich'', is a 
potential threat to roundtail chub. ``Ich'' has occurred in some 
Arizona streams, probably favored by high temperatures and crowding as 
a result of drought (Mpoame 1982, p. 45). This protozoan becomes 
embedded under the skin and within the gill tissues of infected fish. 
When the ``Ich'' matures, it leaves the fish, causing fluid loss, 
physiological stress, and sites that are susceptible to infection by 
other pathogens. If the ``Ich'' are present in large enough numbers, 
they can also impact respiration because of damaged gill tissue.
Conservation Actions Relevant to Factor C
    All three of the conservation agreements have various provisions to 
address the threat of nonnative species. The Range-wide Agreement 
recommends that State conservation agreements include provisions to 
control (as feasible and where possible) threats posed by nonnative 
species that compete with, prey upon, or hybridize with roundtail chub. 
The Arizona Agreement addresses the threat of predation and competition 
from nonnative species, as well as the threat of disease and parasites, 
in its provisions for habitat protection. These provisions include: 
managing detrimental nonnative aquatic species in streams designated 
for conservation of the subject species; evaluating effectiveness of 
nonnative management efforts; and managing the spread of infectious 
diseases and parasites to habitats of the subject species. The Arizona 
Agreement also includes an indentified deliverable of a native fish 
management plan that would also serve to address this threat.
    The New Mexico Plan includes the following provisions to address 
the threat of nonnative species:
    (1) Determine the distribution and abundance of nonnative species 
in the San Juan and Gila River watersheds and the physical barriers to 
their expansion;
    (2) Investigate the impacts, particularly competition, habitat 
modification, and predation, of nonnative species on roundtail chub;
    (3) Determine areas of the San Juan and Gila River watersheds where 
limited nonnative species distribution and abundance may provide 
opportunities for chub restoration;
    (4) Work with sport fish managers to coordinate native and 
nonnative fish management and identify stream areas expressly for 
recovery of native species;
    (5) When appropriate and feasible, remove nonnative species that 
present a threat to roundtail, Gila, and headwater chubs;
    (6) Prevent the introduction of nonnative species into the 
watersheds utilizing existing information and programs when possible;
    (7) Support efforts to re-establish the historical native aquatic 
community in ecologically appropriate habitats in the San Juan and Gila 
River basins utilizing existing programs when possible; and
    (8) Inform local resource users about the impacts of nonnative 
species on roundtail chub.
    Specific actions implemented through the conservation agreements to 
address the threats under Factor C include fisheries management 
planning efforts and creation of new chub populations in nonnative-
fish-free habitats. AGFD convened a Statewide Fish Management Team in 
2008, which developed a process to delineate fish management strategies 
Statewide to address the dual mandates of providing native fish habitat 
and sport fish angling opportunities for the public. AGDF intends that 
this process will serve as the deliverable management plan for the 
Arizona Agreement, and will facilitate sport fish and native fish 
management decisions throughout Arizona. As discussed in the Status and 
Distribution of the Lower Colorado River DPS section above, AGFD and 
NMDGF have created four new populations of roundtail chub, two in 
streams (Ash Creek and Roundtree Canyon) and two in pond refuges (the 
Southwest Academy and Gila River Ranch Preserve refuge ponds). These 
efforts are too new to evaluate their success, but such projects will 
be essential to reversing the decline of the roundtail chub.
Summary of Factor C
    Predation and competition with nonnative aquatic species, and in 
particular fish, are, along with dewatering of habitat, the most 
significant threats to the roundtail chub in the lower Colorado River 
basin. Nonnative aquatic species are a threat to every population of 
roundtail chub with the possible exception of recent transplants into 
Roundtree Canyon and Ash Creek, and perhaps Fossil Creek and Aravaipa 
Creek, based on long-term low levels of occurrence of nonnatives in 
these streams and presence of natural or manmade fish barriers (Voeltz 
2002, p. 47; U.S. Forest Service 2004, p. 1). No attempt has been made 
to quantify the amount of range of these species affected by parasites, 
however, parasites have been documented in numerous populations and 
likely occur throughout the range of these species (Voeltz 2002, pp. 
18-19). Although some actions have been implemented through 
conservation agreements for roundtail chub to address this threat, 
these actions are either not yet complete or too recently completed to 
evaluate their success and contribution to the status of the roundtail 
chub.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

Existing Regulatory Mechanisms
    There are currently no specific Federal protections for roundtail 
chub, and generalized Federal protections found in forest plans, Clean 
Water Act dredge and fill regulations for streams, and other statutory, 
regulatory, or policy provisions have been inadequate to ameliorate the 
threats to roundtail chub in the lower Colorado River basin. Existing 
Federal and State regulations and planning have not achieved 
significant conservation of roundtail chub and its habitat. Although we 
are aware that roundtail chub occurs on Tribal lands, we do not have 
sufficient information to evaluate the effectiveness of Tribal 
management.
    As described in Factor C, introductions of nonnative fish are 
likely a significant threat to roundtail chub. Fish introductions are 
illegal unless approved by the respective States. However, enforcement 
is difficult. Many nonnative fish populations are established through 
illegal introductions. Nine species of fish, crayfish, and waterdogs or 
tiger salamanders (Ambystoma pigrimum) may be legally used as bait in 
Arizona, all of which are nonnative to the State of Arizona, and 
several of which are known to have serious adverse effects on native 
species. The portion of the State in which use of live bait is 
permitted is limited. The use of live bait is restricted in some of the 
Gila River system in Arizona (AGFD 2008, p. 28), but the use of live 
bait species (such as green sunfish) is still permitted in areas such 
as the Verde River that currently

[[Page 32375]]

have roundtail chub populations. New Mexico only allows the use of 
fathead minnow as a live bait-fish in the Gila River drainage in New 
Mexico, which covers the extent of the range of roundtail chub in the 
lower Colorado River basin in New Mexico (NMDGF 2008, p. 8). Arizona 
and New Mexico also continue to stock nonnative sport fishes, including 
such likely predators and competitors as largemouth bass, channel 
catfish, rainbow trout, and brown trout, for recreational angling 
within areas that are connected to habitat of roundtail chub.
    Although restrictions on use of live bait help reduce the input of 
nonnative species into roundtail chub habitat, this does little to 
reduce unauthorized bait use or other forms of ``bait-bucket'' transfer 
(e.g., illegal stock of sport fish, dumping of unwanted aquarium fish) 
not directly related to bait use. Such ``bait-bucket'' transfers can be 
expected to increase as the human population of Arizona increases and 
as nonnative species remain available to the public through aquaculture 
and the aquarium trade.
    AGFD also regulates nonnative species that can be legally brought 
into the State. Prohibited nonnative species are put onto the 
Restricted Live Wildlife List (Commission Order 12-4-406). However, 
species are allowed unless they are prohibited by placement on the 
list, rather than the more conservative approach of being prohibited 
unless specifically allowed. This allows the opportunity for many 
noxious nonnatives to be legally imported and introduced into Arizona. 
New Mexico has adopted a more stringent approach; no live animal 
(except domesticated animals or domesticated fowl or fish from 
government hatcheries) is allowed to be imported without a permit (NMS 
17-3- 32). However, the majority of the roundtail chub's range in the 
lower Colorado River basin occurs within Arizona.
    Existing water laws in Arizona and New Mexico are inadequate to 
protect wildlife. The presence of water is clearly a requirement for 
the roundtail chub. Gelt (2008, pp. 1-12) highlighted the fact that, 
because existing water laws are old, they reflect a legislative 
interpretation of the resource that is not consistent with what is 
known today about hydrology. For example, over 100 years ago when 
Arizona's water laws were written, the important connection between 
groundwater and surface water was not known (Gelt 2008, pp. 1-12). Gelt 
(2008, pp. 8-9) suggested that preserving stream flows and riparian 
areas may be better accomplished by curtailing surface water uses 
rather than groundwater uses, and that the prior appropriation doctrine 
(appropriation of water rights based upon the water law concept of 
``first in use, first in rights'') may be outdated and impractical for 
arid areas like Arizona.
    The Federal Land Policy and Management Act of 1976 (43 U.S.C. 1701 
et seq.) and the National Forest Management Act of 1976 (16 U.S.C. 1600 
et seq.) direct the Secretary of the Interior, through BLM, and Forest 
Service, respectively, to prepare programmatic-level management plans 
to guide long-term resource management decisions. In addition, the U.S. 
Forest Service is required to manage habitat to provide appropriate 
ecological conditions to support a diversity of native plant and animal 
species (36 CFR 219.10). The Forest Service is the largest landowner 
and manager of roundtail chub habitat and lists the roundtail chub as a 
sensitive species in the lower Colorado River basin in the southwestern 
region (Arizona and New Mexico). The BLM is updating its sensitive 
species list for Arizona and has indicated they will add roundtail 
chub. However, a sensitive species designation provides little 
protection to the roundtail chub because it only requires the Forest 
Service and BLM to analyze the effects of their actions on sensitive 
species, but does not require that they choose environmentally benign 
actions. Most of these areas where the majority of extant populations 
of roundtail chub occur are managed by the Forest Service or BLM; thus 
ongoing management by these agencies has not prevented adverse impacts 
to roundtail chub habitat. Although both agencies have riparian 
protection goals, neither agency has specific management plans for the 
roundtail chub.
    Wetland values and water quality of aquatic sites inhabited by the 
roundtail chub are afforded varying protection under the Federal Water 
Pollution Control Act of 1948 (Clean Water Act; 33 U.S.C. 1251-1376), 
as amended; Federal Executive Orders 11988 (Floodplain Management) and 
11990 (Protection of Wetlands); and section 404 of the Clean Water Act, 
which regulates dredging and filling activities in waterways. Water 
quality in the range of the roundtail chub has declined despite these 
laws. The Arizona Department of Environmental Quality (2008) has 
identified several streams with water quality problems occupied by 
roundtail chub. Oak Creek exceeds the total maximum daily load for 
Escherichia coli (E. coli) contamination, due to a combination of 
recreation, septic systems, urban runoff, and livestock grazing. 
Boulder Creek exceeds the total maximum daily load for benzene, 
manganese, mercury, pH, arsenic, copper, and zinc as a result of mining 
activities. The Verde River exceeds the total maximum daily load for 
turbidity/sediment due to livestock grazing, urban development, and 
road use and maintenance. The Arizona Department of Environmental 
Quality is implementing actions through drainage water quality plans to 
correct these problems, but they are ongoing and not likely to be 
resolved in the near future. Our information indicates that the status 
of the roundtail chub in these areas has declined, although it is 
unclear whether this is due to these water quality issues (Voeltz 2002, 
pp. 35, 72).
    The NMDGF has adopted a wetland protection policy whereby they do 
not endorse any project that would result in a net decrease in either 
wetland acreage or wetland habitat values. This policy may afford some 
protection to roundtail chub habitat, although it is advisory only and 
destruction or alteration of wetlands is not regulated by State law. 
The State of Arizona Executive Order Number 89-16 (Streams and Riparian 
Resources), signed on June 10, 1989, directs State agencies to evaluate 
their actions and implement changes, as appropriate, to allow for 
restoration of riparian resources. Implementation of this regulation 
may have reduced adverse effects of some State actions on the habitat 
of the roundtail chub; however, we have no monitoring information on 
the effects of this State Executive Order, nor do we have information 
indicating that actions taken under it have been effective in reducing 
adverse effects to the roundtail chub.
    The National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 
4321 et seq.) requires Federal agencies to consider the environmental 
impacts of their actions. Most actions taken by the Forest Service, 
BLM, and other Federal agencies that affect the roundtail are subject 
to NEPA. NEPA requires Federal agencies to describe the proposed 
action, consider alternatives, identify and disclose potential 
environmental impacts of each alternative, and involve the public in 
the decision-making process. However, Federal agencies are not required 
to select the alternative having the least significant environmental 
impacts. A Federal action agency may select an action that will 
adversely affect sensitive species provided that these effects were 
known and identified in a NEPA document.
    The status of roundtail chub on Tribal lands is not well known. Any 
regulatory or other protective measures for the

[[Page 32376]]

species on Tribal lands would be at the discretion of the individual 
Tribe, and non-Tribal entities often have little information with which 
to evaluate effectiveness. The San Carlos Apache Tribe has developed a 
fisheries management plan that provides protection to roundtail chub, 
although there are only two populations that potentially occur on San 
Carlos Apache lands, representing a very small percentage of the 
overall range of the species in the lower Colorado River basin. We have 
limited information on threats to populations of roundtail chub on 
Tribal lands, but land uses on Tribal lands include livestock grazing, 
recreation, limited fuel wood harvest, limited agriculture, fisheries 
and wildlife management, and localized municipal, urban, and rural 
development and associated water use. The White Mountain Apache Tribe 
is preparing a fisheries management plan that, when completed, could 
benefit roundtail chub because 8 of the 31 populations occur wholly or 
in part on White Mountain Apache Tribal lands.
    The State of New Mexico lists the roundtail chub as ``State 
Endangered'' under its Wildlife Conservation Act, which prohibits take 
(New Mexico Wildlife Conservation Act 17-2-41(B)). In the State of New 
Mexico, an ``Endangered Species'' is defined as ``any species of fish 
or wildlife whose prospects of survival or recruitment within the State 
are in jeopardy due to any of the following factors: (1) The present or 
threatened destruction, modification, or curtailment of its habitat; 
(2) overutilization for scientific, commercial or sporting purposes; 
(3) the effect of disease or predation; (4) other natural or manmade 
factors affecting its prospects of survival or recruitment within the 
State; or (5) any combination of the foregoing factors'' as per New 
Mexico Statutory Authority 17-2-38.D. ``Take,'' defined as ``to harass, 
hunt, capture or kill any wildlife or attempt to do so'' by New Mexico 
Statutory Authority 17-2-38.L., is prohibited without a scientific 
collecting permit issued by the NMDGF as per New Mexico Statutory 
Authority 17-2-41.C and New Mexico Administrative Code 19.33.6. 
However, while the NMDGF can issue monetary penalties for illegal take 
of roundtail chub, the same provisions are not in place for actions 
that result in loss or modification of habitat (New Mexico Statutory 
Authority 17-2-41.C and New Mexico Administrative Code 19.33.6).
    The roundtail chub is identified on the AGFD draft document (never 
finalized), Wildlife of Special Concern (AGFD 2006b, p. 5). The purpose 
of the Wildlife of Special Concern list is to provide guidance in 
habitat management implemented by land management agencies. 
Additionally, the roundtail chub is considered a ``Tier 1b Species of 
Greatest Conservation Need'' in the AGFD draft document, Arizona's 
Comprehensive Wildlife Conservation Strategy (AGFD 2006c, p. 371). The 
purpose for the Comprehensive Wildlife Conservation Strategy is to 
``provide an essential foundation for the future of wildlife 
conservation and a stimulus to engage the States, federal agencies, and 
other conservation partners to strategically think about their 
individual and coordinated roles in prioritizing conservation efforts'' 
(AGFD 2006c, p. 2). A ``Tier 1b Species of Greatest Conservation Need'' 
is one that requires immediate conservation actions aimed at improving 
conditions through intervention at the population or habitat level 
(AGFD 2006c, p. 32).
    As discussed in Factor B, up to one roundtail chub may be taken and 
possessed per day via angling Statewide in Arizona, with the exception 
of Fossil Creek, which is catch and release only, from Oct 3, 2009, 
through April 30, 2010. Take of roundtail chub is also permitted in 
Arizona via issuance of a scientific collecting permit (Ariz. Admin. 
Code R12-4-401 et seq.). While the AGFD can seek criminal or civil 
penalties for illegal take of roundtail chub, the same provisions are 
not in place for actions that result in destruction or modification of 
roundtail chub habitat.
    SRP has completed two habitat conservation plans (HCPs) for its 
operation of Roosevelt Dam and Lake and its operation of Horseshoe and 
Bartlett reservoirs (SRP 2006, 2008, 2009). Through implementation of 
the Roosevelt Habitat Conservation Plan, SRP has permanently protected 
and will manage land and water rights for more than 2,000 ac (809 ha) 
of riparian and aquatic habitat along Tonto Creek and the middle Gila, 
lower San Pedro, and Verde Rivers. Conservation measures on these 
properties, such as increasing instream flows, excluding livestock, 
improving channel integrity, excluding vehicle and off-road vehicle 
traffic, abating wildfires, and promoting riparian ecosystem health, 
will continue in perpetuity and will directly benefit native fishes, 
including the roundtail chub. For example, one such SRP-owned and 
maintained property is the Camp Verde Riparian Preserve near Camp 
Verde, Arizona, on the Verde River, which contains a portion of the 
Verde River occupied by roundtail chub (SRP 2006, pp. 26-28).
    The HCP for Horseshoe and Bartlett Reservoirs specifically covers 
the roundtail chub and includes numerous minimization and mitigation 
measures that will benefit the species, including: rapid drawdown of 
Horseshoe Lake annually to disadvantage nonnative fish species by 
adversely affecting the recruitment and growth of these species; 
providing funding to AGFD for creation and maintenance of fish rearing 
facilities at its Bubbling Ponds State Fish Hatchery; providing funding 
and support for native fish stocking, including stocking of roundtail 
chub; watershed management efforts that serve to maintain quality and 
quantity of instream flows; native fish monitoring; and public outreach 
(SRP 2008, pp. 193-201). SRP is also a signatory to the Arizona 
Agreement, and in this capacity, has funded roundtail chub genetics 
research and development of roundtail chub broodstock. SRP also works 
with AGFD to salvage roundtail chub from its canals (SRP 2009, pp. 6-
7).
    Roundtail chub derives some conservation benefit from its co-
occurrence with other listed species and critical habitat in the lower 
Colorado River basin. As an example, Bureau of Reclamation's 
interagency consultation (section 7 compliance) on the operation and 
maintenance of the Central Arizona Project (CAP), a water delivery 
system designed to bring water from the Colorado River to portions of 
Pima, Pinal, and Maricopa counties in Arizona, has greatly benefited 
the species. Biological opinions on the CAP addressed the spread of 
nonnative aquatic species through the project canals from the Colorado 
River into the Gila and Santa Cruz River basins (Service 2001, 2008). 
Conservation measures included in these biological opinions to benefit 
listed fish and amphibian species (including the spikedace, loach 
minnow, Gila topminnow, desert pupfish, Gila chub, and Chiricahua 
leopard frog (Rana chiricahuensis)) have benefitted the roundtail chub 
and likely will into the future. In 2004, nonnative fish were removed 
from Fossil Creek through chemical renovation to benefit native fish 
species including the roundtail chub. The Bureau of Reclamation, in 
cooperation with AGFD, the Service, and the Forest Service, also 
installed a fish barrier in lower Fossil Creek to prevent reinvasion of 
nonnative fish. The Fossil Creek restoration project was a conservation 
measure included in the CAP biological opinion issued to the Bureau of 
Reclamation, and it resulted in the creation of the only stable-secure

[[Page 32377]]

population of roundtail chub currently in existence in the lower 
Colorado River basin.
Conservation Actions Relevant to Factor D
    The Range-wide Agreement recommends that the State plans include 
provisions to assure adequate regulatory protection for the roundtail 
chub, flannelmouth sucker, and bluehead sucker within the signatory 
States, and to install regulatory mechanisms for the long-term 
protection of habitat (e.g., conservation easements, water rights). The 
Range-wide Agreement also recommends that States develop multi-State 
nonnative stocking procedure agreements that protect all three species 
and potential reestablishment sites from the threat of nonnative 
species. The Arizona Agreement includes the provision to maintain 
instream flow by securing habitat through acquisition of water rights 
or agreements with water rights holders to maintain instream flow. 
Implementation of these provisions so far has resulted in the U.S. 
Forest Service application for an instream flow right on Cherry Creek, 
which contains roundtail chub, and SRP and Conservancy applications to 
the Arizona Department of Water Resources for instream flow rights on 
the Verde River. These measures and actions may result in further 
regulatory protection for roundtail chub by legally protecting flows 
for the species.
Summary of Factor D
    Existing regulations within the range of the roundtail chub address 
the direct take of individuals without a permit, and unpermitted take 
is not thought to be a threat to roundtail chub. However, Arizona and 
New Mexico statutes do not provide protection of habitat and 
ecosystems. Currently, there are no regulatory mechanisms in place that 
specifically target the conservation of roundtail chub or its habitat. 
General regulatory mechanisms protecting the quantity and quality of 
water in riparian and aquatic communities are inadequate to protect 
water resources for the roundtail chub, particularly in the face of the 
significant human population growth expected within the historical 
range of the chub discussed under Factor A. Conservation actions 
defined in existing conservation agreements may provide some additional 
regulatory protection, in particular through development of instream 
flow rights to protect habitat for the roundtail chub, but no instream 
flow rights have yet been acquired, although several applications for 
specific waters have been submitted.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Fragmented Populations and Stochastic Events
    The rarity of roundtail chub increases the possible extinction risk 
associated with stochastic events such as drought, flood, and wildfire. 
Roundtail chub populations have been fragmented and isolated to smaller 
stream segments and may be vulnerable to natural or manmade factors 
(e.g., drought, groundwater pumping) that might further reduce their 
population sizes. Maintaining several populations with relatively 
independent susceptibility to threats is an important consideration in 
the long-term viability of a species (Shaffer 1987; Goodman 1987). 
Redundant populations provide security from catastrophic events or 
repeated recruitment failure. For example, consider that a single 
hypothetical population has a probability of extinction from a 
catastrophic event of 10 percent in 200 years. If two populations are 
independent, the probability of both going extinct is 1 percent (0.12). 
For three populations, the probability reduces to 0.1 percent (0.13). 
Even with an extinction probability of 25 percent for one population, 
the probability of extinction for two and three populations is 6.3 
percent and 1.6 percent, respectively (Casagrandi and Gatto 1999). 
Fagan et al. (2002) determined that individual roundtail chub 
populations have a 0.41 percent probability of extirpation given 
current status and levels of fragmentation and isolation. Providing for 
multiple populations that are secure and stable (as defined above in 
Table 1, a population that is recruiting with multiple age classes and 
that is free from threats) in a single drainage basin will provide 
increased redundancy and reduce the likelihood of extirpation. We 
consider a particular basin or management area to be at risk of 
extirpation if there are fewer than a minimum of two stable-secure 
populations because any single population can be eliminated by 
stochastic events or catastrophic disturbance, such as fire. We only 
consider roundtail chub to be stable-secure in one stream, Fossil 
Creek.
    In general, Arizona is an arid State; about one-half of Arizona 
receives less than 10 in. (25 cm) of rain a year. Dewatering and other 
forms of habitat loss have resulted in fragmentation of roundtail chub 
populations. We anticipate that water demands from a rapidly increasing 
human population may further reduce habitat available to this species, 
and could further fragment populations. In examining the relationship 
between species distribution and extinction risk in southwestern 
fishes, Fagan et al. (2002, p. 3250) found that the number of 
occurrences or populations of a species is less significant a factor in 
determining extinction risk than is habitat fragmentation. 
Fragmentation of habitat may also cause the roundtail chub to be 
vulnerable to extinction from threats of further habitat loss and 
competition from nonnative fish because immigration and recolonization 
from adjacent populations is less likely. The risk of extirpation of 
individual populations of this species appears to be quite high given 
the degree of fragmentation (Fagan et al. 2002, p. 3254), that only one 
population is considered stable and secure, and that many threats are 
predicted to increase in severity in the future.
Climate Change
    Several recent studies predict continued drought in the 
southwestern United States, including the lower Colorado River basin, 
due to global climate change. Seager et al. (2007, pp. 1181-1184) 
analyzed 19 different computer models of differing variables to 
estimate the future climatology of the southwestern United States and 
northern Mexico in response to predictions of changing climatic 
patterns. All but one of the 19 models predicted a drying trend within 
the Southwest (Seager et al. 2007, p. 1181). A total of 49 projections 
were created using the 19 models, and all but 3 predicted a shift to 
increasing aridity (dryness) in the Southwest as early as 2021-2040 
(Seager et al. 2007, p. 1181). Recently published projections of 
potential reductions in natural flow in the Colorado River basin by the 
mid-21st century range from approximately 45 percent by Hoerling and 
Eischeid (2006, p. 3989) to approximately 6 percent by Christensen and 
Lettenmaier (2006, pp. 3727-3729). The U.S. Climate Change Science 
Program recently completed a report entitled ``Abrupt Climate Change, A 
report by the U.S. Climate Change Science Program and the Subcommittee 
on Global Change Research'' (U.S. Climate Change Science Program 
2008a). Regarding the southwest United States, the summary and findings 
concluded: ``Climate model studies over North America and the global 
subtropics indicate that subtropical drying will likely intensify and 
persist in the future due to

[[Page 32378]]

greenhouse warming. This drying is predicted to move northward into the 
southwestern United States. If the model results are correct, then the 
southwestern United States may be beginning an abrupt period of 
increased drought'' (U.S. Climate Change Science Program 2008b, p. 2).
    If predicted effects of climate change result in persistent drought 
conditions in the Colorado River basin similar or worse than those seen 
in recent years, water resources will become increasingly taxed as 
supplies dwindle and demand stays the same or increases. Likewise, 
there would be increased demand on surface and groundwater supplies in 
Arizona. Clearly, permanent water is crucial for the continued survival 
of native fish in the region, including roundtail chub. Essentially the 
entire range of the roundtail chub in the lower Colorado River basin is 
predicted to be at risk of becoming more arid (Seager et al. 2007, pp. 
1183-1184), which has severe implications to the integrity of aquatic 
and riparian ecosystems and the water that supports them. Perennial 
streams in the region may become intermittent and streams that are 
currently intermittent may become unsuitable or dry completely.
    Changes to climatic patterns may warm water temperatures, alter 
stream flow events, and increase demand for water storage and 
conveyance systems (Rahel and Olden 2008, pp. 521-522). Warmer water 
temperatures across temperate regions are predicted to expand the 
distribution of existing aquatic nonnative species by providing 31 
percent more suitable habitat for aquatic nonnative species. This 
conclusion is based upon studies that compared the thermal tolerances 
of 57 fish species with predictions made from climate change 
temperature models (Mohseni et al. 2003, p. 389). Eaton and Scheller 
(1996, p. 1111) reported that while several cold-water fish species in 
North America are expected to have reductions in their distribution 
from effects of climate change, several warmwater fish species are 
expected to increase their distribution. In the southwestern United 
States, this situation may occur where water persists but water 
temperature warms to a level suitable for nonnative species that were 
previously physiologically precluded from occupation of these areas. 
Species that are particularly harmful to roundtail chub populations 
such as the green sunfish, channel catfish, largemouth bass, and 
bluegill are expected to increase their distribution by 7.4 percent, 
25.2 percent, 30.4 percent, and 33.3 percent, respectively (Eaton and 
Scheller 1996, p. 1111). Rahel and Olden (2008, p. 526) expect that 
increases in water temperatures in drier climates such as the 
southwestern United States will result in periods of prolonged low 
flows and stream drying. These effects from changing climatic 
conditions may have profound effects on the amount, permanency, and 
quality of habitat for the roundtail chub. Warmwater nonnative species 
such as red shiner, common carp, mosquitofish, and largemouth bass are 
expected to benefit from prolonged periods of low flow (Rahel and Olden 
2008, p. 527).
    Rahel et al. (2008, p. 551) examined climate change models, 
nonnative species biology, and ecological observations, and concluded 
that climate change could foster the expansion of nonnative aquatic 
species into new areas, magnify the effects of existing aquatic 
nonnative species where they currently occur, increase nonnative 
predation rates, and heighten the virulence of disease outbreaks in 
North America. Many of the nonnative species have similar, basic 
ecological requirements as our native species, such as the need of 
nonnative fish species for permanent or nearly permanent water. Rahel 
et al. (2008, pp. 554-555; and from Carveth et al. 2006, p. 1435) found 
that climate change will likely favor nonnative fish species such as 
largemouth bass, yellow bullhead, and green sunfish over roundtail 
chub, in part because they have higher temperature tolerances. Also, 
drying of stream channels will create less habitat and greater 
competition due to limited space and habitat. Thus climate change can 
eliminate roundtail chub habitat through at least two mechanisms: 
directly, by drying up aquatic habitats due to decreases in 
precipitation and stable or increasing human demand for water 
resources; and indirectly by improving conditions for nonnative 
species, increasing their proliferation, and thereby increasing the 
threat from nonnative fish predation and competition.
    Rahel et al. (2008, p. 555) also noted that climate change could 
facilitate expansion of nonnative parasites. This could be an important 
threat to roundtail chub. Optimal Asian tapeworm development occurs at 
25-30 [deg]C (77-86 [deg]F) (Granath and Esch 1983, p. 1116), and 
optimal anchorworm temperatures are 23-30 [deg]C (73-86 [deg]F) (Bulow 
et al. 1979, p. 102). Cold water temperatures in parts of the range of 
the roundtail chub may have prevented these parasites from completing 
their life cycles and limited their distribution. Warmer climate trends 
could result in warmer overall water temperatures, increasing the 
prevalence of these parasites.
    The effects of the water withdrawals discussed above may be 
exacerbated by the current, long-term drought facing the arid 
southwestern United States. Philips and Thomas (2005, pp. 1-4) provided 
streamflow records that indicate that the drought Arizona experienced 
between 1999 and 2004 was the worst drought since the early 1940s and 
possibly earlier. The Arizona Drought Preparedness Plan Monitoring 
Technical Committee (2008) assessed Arizona's drought status through 
June of 2008 in watersheds where the roundtail chub occurs or 
historically occurred. They found that the Verde and San Pedro 
watersheds continue to experience moderate drought (Arizona Drought 
Preparedness Plan Monitoring Technical Committee 2008), and the Salt, 
Upper Gila, Lower Gila, and Lower Colorado watersheds were abnormally 
dry (Arizona Drought Preparedness Plan Monitoring Technical Committee 
2008). Ongoing drought conditions have depleted recharge of aquifers 
and decreased baseflows in the region. While drought periods have been 
relatively numerous in the arid Southwest from the mid-1800s to the 
present, the effects of human-caused impacts on riparian and aquatic 
communities may compromise the ability of these communities to function 
under the additional stress of prolonged drought conditions.
Conservation Agreements
    As discussed in the ``Conservation Actions Relevant to Factor A'' 
section above, there are three wide-ranging plans that address the 
ongoing conservation of the roundtail chub. The Utah Department of 
Natural Resources' Range-wide Agreement was finalized and signed by all 
the Colorado River basin States in 2004. The Range-wide Agreement 
depends heavily on individual State plans for its implementation. The 
objectives of the Range-wide Agreement are to:
    (A) Establish or maintain populations sufficient to ensure the 
conservation of each species within the State;
    (B) Establish or maintain sufficient connectivity between 
populations so that viable metapopulations are established or 
maintained;
    (C) As feasible, identify, significantly reduce or eliminate 
threats to the conservation of these species.
    To meet its obligations under the Range-wide Agreement, New Mexico 
completed a recovery plan for the roundtail chub in November of 2006, 
the ``Colorado River Basin Chubs Recovery Plan'' (New Mexico Plan)

[[Page 32379]]

(Carman 2006, p. 39). The New Mexico Plan includes a management 
strategy with the goal of establishing roundtail chub populations that 
are secure and self-sustaining throughout their historical ranges in 
New Mexico, and the objective for at least one sufficient, self-
sustaining, secure population of roundtail chub in the mainstem of the 
Gila River in New Mexico (Carman 2006, p. 49). The New Mexico Plan 
management strategy also includes specific and comprehensive management 
issues and strategies with corresponding implementation tasks and a 
timeline for completion. The implementation tasks provide a 
comprehensive list of conservation measures including: compiling 
information on status and potential habitat; improving knowledge of 
historical and current population dynamics; creating refuge populations 
of chub lineages; restoring and securing habitats; if necessary, 
augmenting populations; if possible, establishing additional 
populations; restricting angling take of headwater chub; controlling 
nonnative species; identifying and reducing information gaps; and 
establishing agreements and partnerships to implement the plan (Carman 
2006, pp. 55-57). Actions taken to date in implementation of the New 
Mexico Plan include the creation of a new refuge population of 
roundtail chub at the Conservancy's Gila River Preserve farm pond in 
2008 using offspring of wild-caught Verde River fish from the AGFD 
Bubbling Ponds Fish Hatchery. The NMDGF plans to complete health and 
genetic studies on these fish, and if appropriate, their offspring will 
be stocked into the mainstem Gila River in New Mexico. The NMDGF has 
also been working with partners to secure habitat through purchases and 
land management. In 2007, the Department and the Conservancy purchased 
168 ac (68 ha) of riparian and river habitat in the Gila-Cliff Valley.
    The goal of the Arizona Agreement is to ensure the conservation of 
roundtail chub, headwater chub, flannelmouth sucker, Little Colorado 
River sucker, bluehead sucker, and Zuni bluehead sucker populations 
throughout Arizona. The Arizona Agreement's objective is to address and 
ameliorate the five listing factors in accordance with section 4(a)(1) 
of the Act; the Arizona Agreement objectives also correspond to those 
in the Range-wide Agreement (see above). The Arizona Agreement includes 
a strategy that is comprehensive and includes numerous conservation 
strategy tasks. Key tasks include: create a management plan; create a 
Statewide management team; conduct status assessments; identify 
threats; conduct research; secure, enhance, maintain, and create 
habitat; manage detrimental nonnative fish/aquatic species; manage the 
spread of infectious diseases and parasites; enhance or restore 
connectedness and opportunities for migration; create, maintain and 
evaluate fish refugia; establish and enhance populations; monitoring; 
and outreach (AGFD 2006a, pp. 45-52). The Arizona Agreement also 
includes success criteria, including: population stability criteria for 
sizes and numbers of populations to maintain roundtail chub; threat 
reduction success criteria, to determine if threats have been 
adequately mitigated or eliminated, and monitoring to evaluate status 
and trend of populations, and determine if habitat is being adequately 
maintained.
    AGFD has established a Statewide Management Team to implement the 
Arizona Agreement; signatories include the Bureau of Reclamation, the 
Hualapai Tribe; SRP; BLM; the Arizona State Lands Department; the 
Arizona Department of Water Resources; the Conservancy; the Forest 
Service; and the Fish and Wildlife Service. Under the Arizona 
Agreement, AGFD and its partners have implemented several conservation 
actions that have benefited the roundtail chub, including stocking 
roundtail chub into two new habitats that are free from nonnative 
fishes, Roundtree Canyon and Ash Creek. These stockings are too new to 
evaluate whether roundtail chub has become established, but if 
successful, these efforts will help conserve the species by creating 
two new populations that are largely free from significant threats. 
AGFD plans to establish another new population of roundtail chub in 
Houston Creek in 2009. AGFD is also working with various partners to 
develop operating criteria for Alamo Dam on the Bill Williams River to 
conserve roundtail chub, and is finalizing broodstock and fishery 
management plans, which will guide the maintenance and propagation of 
different stocks for use in restoration of populations throughout the 
range of the DPS and management of individual population units, 
management areas, and conservation units.
    The Range-wide Agreement and the Arizona Agreement depend on good-
faith efforts from signatories for their implementation, and identify 
the need to develop funding sources for their implementation. Likewise, 
the New Mexico Plan commits to using existing resources and funding 
sources, to the extent possible, to implement the plan, and also 
identifies the need for additional sources for full implementation. No 
funding agreements are in place to support these efforts. Although a 
few conservation actions have been implemented to benefit roundtail 
chub, as discussed above, the Range-wide Agreement, the Arizona 
Agreement, and the New Mexico Plan, and their comprehensive lists of 
tasks, which if fully implemented would significantly aid in the 
conservation of roundtail chub, are in the early stages of 
implementation at this point in time. Specific actions identified in 
these plans, either planned or implemented, that address individual 
threats are identified in Factors A to E as appropriate.
    The Arizona Agreement has resulted in two new populations of 
roundtail chub, one in a 1.2-mi (2-km) tributary to the Verde River, 
Roundtree Canyon, and one in a 0.6-mi (1-km) tributary of the Salt 
River, Ash Creek. These translocations are too new to evaluate their 
success, having been completed in 2008 and 2007 respectively, but they 
could potentially benefit the species. AGFD is also planning to execute 
a translocation into a second tributary of the Verde River, Houston 
Creek, on the Tonto National Forest, in 2009. Another conservation 
measure being undertaken as a result of the conservation agreements is 
the establishment of refuge populations and broodstock. Refuge or 
sanctuary populations have proven to be important in the conservation 
of native fish in the Southwest by creating predator-free habitats 
(Mueller 2008), and use of broodstock populations has prevented the 
extinction of bonytail (Hedrick et al. 2000). AGFD has developed 
broodstock management plans for the Verde River and Chevelon Creek 
(Cantrell 2009, p. 5). Refuge populations provide both broodstock and a 
secure population to preserve the genetic integrity of a population. 
AGFD and the NMDGF recently created a refuge population in New Mexico 
at the Conservancy Gila River Preserve refuge pond near the Gila River. 
AGFD has also created a refuge at the Southwest Academy on Wet Beaver 
Creek near Camp Verde, Arizona. Both of these refuges were created with 
Verde River broodstock from a broodstock population at the AGFD 
Bubbling Ponds fish hatchery. AGFD plans to create additional refuge/
broodstock populations for other conservation management units, with a 
minimum of one for each management area (Cantrell 2009, p. 5).

[[Page 32380]]

Conservation Actions Relevant to Factor E
    The Arizona Agreement includes provisions to address the threat of 
population fragmentation, identifying the need to maintain 
connectivity, or at least gene flow, even by artificial means, between 
populations. If connectivity between occupied habitats cannot be 
maintained via natural connection, the Arizona Agreement recommends 
considering the practice of moving individuals of the subject species 
between fragmented populations. Further, reducing existing stressors by 
implementing the conservation agreements will give existing populations 
additional resiliency to face the stresses presented by climate change.
Summary of Factor E
    Threats to roundtail chub are magnified by the fragmentation of 
existing populations. All but one model evaluating changing climatic 
patterns for the southwestern United States and northern Mexico predict 
a drying trend for the region (Seagar et al. 2007, pp. 1181-1184). We 
acknowledge that drought and the loss of surface water in riparian and 
aquatic communities are related to changing climatic conditions (Seagar 
et al. 2007, pp. 1181-1184). The extent to which changing climate 
patterns will affect the roundtail chub is not known with certainty at 
this time. However, threats to the roundtail chub identified in Factors 
A and C will likely be exacerbated by changes to climatic patterns in 
the southwestern United States due to increasing drought and reduction 
of surface waters if the predicted patterns are realized. Conservation 
agreements and associated plans have been developed for roundtail chub 
in the lower Colorado River basin, and some actions have been 
implemented as a result that benefit and help conserve the roundtail 
chub, such as the establishment of new populations in nonnative fish-
free habitats and the development of broodstock for use in establishing 
and augmenting populations. These plans also include numerous actions 
to help reduce the threats to the roundtail chub. While we recognize 
the importance of working with our partners in conserving the roundtail 
chub through the implementation of these plans, and recognize that if 
implemented, they will greatly assist in the conservation of roundtail 
chub, these agreements have only recently been completed and are in the 
early stages of implementation.

Summary of Status and Threats

    The following discussion illustrates how the threats to the species 
have affected and are affecting the roundtail chub across the DPS. 
Based on museum records documented in Voeltz (2002, Appendices), we 
suspect that the roundtail chub retained much of its historical 
distribution in the lower Colorado River basin within the United States 
up to and likely through the 1920s. Activities such as the construction 
of dams and water diversions that occurred throughout the early to mid-
1900s for agriculture and regional economic development likely 
eliminated surface flow throughout stream reaches with occupied 
habitat, which led to widespread extirpations of roundtail chub 
populations in areas such as the lower Gila and Salt Rivers in Arizona. 
After the period of dam construction and the subsequent creation of 
reservoirs, widespread nonnative fish stocking efforts ensued 
throughout Arizona beginning in mid 1900s. The effects from this influx 
of nonnative species throughout the Southwest resulted in significant 
declines in native fish and ranid frog distribution and abundance, and 
the subsequent listing of 19 of Arizona's 31 native fish species 
throughout the last 35 years (see discussion in the ``Nonnative 
Species'' section above).
    Currently, there are three specific Management Areas of the DPS. 
Management Area A contains three river basins with the same lineage of 
roundtail chub: The Gila, Salt, and Verde Rivers (Dowling et al. 2008). 
However, these three basins have very limited connectivity between them 
today, and the status of each basin may best be described separately. 
We will therefore discuss each of these river basins separately to 
better understand the status of the Management Area.
    The roundtail chub populations in the Verde River basin have the 
best hydrological connectivity between populations of any basin and the 
only ``stable-secure'' population, in Fossil Creek (Table 2). However, 
the Verde River is fragmented due to the presence of Horseshoe and 
Bartlett reservoirs. Fossil Creek was restored in 2004, and has been 
stocked with native fishes including roundtail chub. Of the other five 
natural populations in the Verde River, one is extirpated, two are 
``stable-threatened'' and two are ``unstable-threatened.'' Reproduction 
and recruitment is documented in the two ``stable-threatened'' 
populations, but even in these, appears sporadic over time (Brouder et 
al. 2001, p. 9). As discussed above (see the Summary of Factors 
Affecting the Species section), the Verde River is experiencing threats 
from numerous land uses, especially water withdrawal with increasing 
demand for the Big Chino aquifer, the source of the Verde River. 
Nonnative species are present in all populations with the exception of 
Fossil Creek. Throughout the Verde River basin, populations seem at 
risk of not achieving long-term persistence due to threats, as only 
sporadic recruitment documented.
    The Salt River populations are difficult to assess due to land 
ownership. The success of Tribal fisheries management plans is 
uncertain. The San Carlos Apache Tribe Fisheries Management Plan is 
complete, but the species has limited occurrence on that reservation. 
The White Mountain Apache Tribe has begun work on a fisheries 
management plan, which is not yet complete. Tribal management affects 
all but two populations in the Salt River basin. Of the two completely 
non-Tribal populations, one is ``stable-threatened'' and one is 
``unstable-threatened.'' Cherry Creek, the lone ``stable-threatened'' 
population, is disconnected from other populations in the Management 
Area, and a single stochastic event, such as wildfire, which has 
recently affected nearby populations, could eliminate the population.
    The roundtail chub populations in the Gila River are almost 
completely extirpated, with the only ``stable-threatened'' population 
in Aravaipa Creek. Aravaipa Creek is protected by fish barriers, 
erected by the Bureau of Reclamation as a result of the CAP biological 
opinions (Service 2001, 2008). Thus the roundtail chub in Aravaipa 
Creek has also benefited from its co-occurrence with the Federally 
listed spikedace and loach minnow. Aravaipa Creek has also benefitted 
from other conservation actions, including those undertaken through 
conservation agreements, such as actions of the Conservancy taken for 
its protection, discussed above (see Conservation Actions Relevant to 
Factor A). But nonnative fish species do occur above the barrier in 
Aravaipa Creek and could conceivably spread. The only other populations 
in the Management Area are Eagle Creek and the upper Gila River in New 
Mexico. Roundtail chub in both of these locations has become very rare 
in recent years (Carman 2006, p. 7; Cantrel 2009, p. 9). Both of these 
populations are subject to numerous threats, including abundant 
nonnative species and dewatering due to ongoing mining operations and 
potential water

[[Page 32381]]

projects resulting from recent water rights settlements.
    Management Area A is thus at a high risk of extirpation for several 
reasons. The management area is made up of fractured basins, the Gila, 
Salt, and Verde Rivers. Many populations have been extirpated, and 
roundtail chub in Eagle Creek and the Upper Gila River has become very 
rare. A number of populations are on Tribal lands and are difficult to 
evaluate in terms of status and future management. Two populations are 
fairly well protected and have a stable status, Fossil and Aravaipa 
Creeks. However, these two locations are no longer connected, and we 
find that their current status is largely due to special management 
resulting from their co-occurrence with already listed fish species. 
All of the other populations apart from Fossil and Aravaipa Creeks in 
Management Area A are likely at significant risk from Factors A and C, 
and in particular, predation from nonnative fish species and 
dewatering.
    Management Area B is the Bill Williams River Basin. Streams in the 
Bill Williams Management Area are highly fragmented and subject to 
summer drying, even under normal conditions, because the area is in the 
driest part of the DPS (Green and Sellers 1964, Figs. 3-5). It is 
likely that all populations in Management Area B are fragmented and 
isolated during the dry season. Remaining populations face increasing 
groundwater development particularly in the Boulder Creek sub-basin, 
and in Kirkland Creek in particular. Only four of the nine extant 
populations are ``stable-threatened'' and those are in isolated 
portions of the drainage. Trout Creek is completely isolated, and the 
Big Sandy River is extirpated. The Burro Creek drainage, which includes 
Boulder and Conger Creeks, has some redundancy, but effluent from 
mining operations and the presence of green sunfish, red shiner, and 
yellow bullhead in Boulder Creek pose a threat to these populations. 
The Santa Maria sub-basin contains three populations, including 
Kirkland and Sycamore Creeks, all of which are considered ``unstable-
threatened'' and at risk from increased groundwater pumping and the 
presence of nonnative fish species. According to AGFD, these streams 
may dry completely in drought and are more vulnerable to the effects of 
climate change (A. Clark, AGFD, pers. comm. 2009). Thus, Management 
Area B is a collection of highly isolated, threatened populations, in a 
very dry region of the DPS.
    Management Area C is the Little Colorado River Basin. Only two 
populations remain: Clear Creek (East Clear Creek) and Chevelon Creek. 
Both are ``unstable-threatened.'' Recent surveyors have commented with 
surprise that these populations persist. For example, Clarkson and 
Marsh (2005b, p. 9) remarked that the occurrence of roundtail chub and 
juvenile roundtail chub in Clear Creek was shocking given the lack of 
occurrence in surveys a year before, and especially given the co-
occurrence and dominance of nonnative fish species in the area. The 
authors would not even speculate on why this rare situation existed, 
but noted that in similar situations in the Southwest, ``natives 
eventually decline and succumb in the presence of nonnative fish 
populations (Marsh and Pacey 2005).'' Further, they found that other 
natives including speckled dace (Rhinichthys osculus), bluehead sucker, 
and Little Colorado spinedace (Lepidomeda vittata) were absent from 
Clear Creek, which Clarkson and Marsh (2005b, p. 9) state ``is likely 
testament to the continuing deterioration of the native fish fauna in 
this area.'' Threats to these two populations include both nonnative 
species and water use. The aquifer that feeds these streams in their 
lower reaches has recently been the subject of study for its use as a 
water supply for nearby mining operations and future development in 
towns of the region such as Flagstaff, Winslow, and Holbrook. 
Therefore, further strain on these systems from increased surface and 
groundwater diversions is likely. Of the three management areas, 
Management Area C appears to be the most threatened and has the poorest 
status. Given the lack of redundancy and resiliency in these 
populations, the loss of the two populations seems very likely in the 
near future without aggressive conservation to reduce threats.
Foreseeable Future
    The Act does not define the term ``foreseeable future.'' However, 
in a January 16, 2009, memorandum addressed to the Acting Director of 
the U.S. Fish and Wildlife Service, the Office of the Solicitor, 
Department of the Interior, concluded, ``* * * as used in the [Act], 
Congress intended the term `foreseeable future' to describe the extent 
to which the Secretary can reasonably rely on predictions about the 
future in making determinations about the future conservation status of 
the species.'' In discussing the concept of foreseeable future for the 
lower Colorado River basin DPS of the roundtail chub, we considered: 
(1) The biological and demographic characteristics of the species (such 
as generation times, population genetics, trends in evidence of 
recruitment within current populations, etc.); (2) our ability to 
predict or extrapolate the effects of threats facing the DPS into the 
future; and (3) the relative permanency or irreversibility of these 
threats.
    Of the threats to the roundtail chub described in our analysis, the 
threats of habitat loss and nonnative species are the most significant. 
Habitat loss has resulted in the loss of large sections of the species' 
former range in the lower Colorado River basin because suitable habitat 
is now gone or so altered as to be permanently unsuitable, and the same 
land use practices that have led to this habitat loss are still 
occurring throughout the range of the DPS and therefore continue to 
constitute a significant threat. The threat of habitat loss is likely 
to not only continue in the future but increase in severity given the 
environmental changes resulting from climate change and increasing 
human populations. The widespread, imminent, and serious threat to the 
long-term sustainability of roundtail chub in the lower Colorado River 
basin from the presence of nonnative aquatic species, especially 
nonnative fishes, compounds the threat of habitat loss. The elimination 
of the single threat of nonnative species, especially fishes, may 
lessen the severity of all other threats. We find that because of the 
potential for habitat loss due to various land uses, in particular 
dewatering, the presence of significant levels of nonnative fish in all 
but one population, and the extent of threats and lack of stability to 
populations throughout the lower Colorado River basin, the viability of 
the DPS is in question into the foreseeable future.
    In response to the impacts to the roundtail chub discussed above 
and in our analysis of threats, the roundtail chub in the lower 
Colorado River basin has been eliminated from approximately 68 to 82 
percent of its historical range over the last 80 years (Voeltz 2002, p. 
83). The most significant period of declines and subsequent 
extirpations of entire populations of roundtail chub likely coincided 
with the proliferation of nonnative species beginning in the 1940s and 
1950s, most notably with the widespread introduction and expansion of 
nonnative fish such as common carp, largemouth bass, green sunfish, and 
channel and flathead catfish. In some areas, the presence of these 
nonnative species appears to be limiting recruitment of roundtail chub, 
with only large adults encountered during surveys (Cantrell 2009, p. 
10).

[[Page 32382]]

    Voeltz (2002, p. 5) defined ``unstable-threatened'' populations of 
roundtail chub as those which exhibited over the past 5-10 years a 
declining population with limited recruitment, and noted 13 such 
populations. Specific instances of apparent recruitment failure have 
been noted in the Verde and Salt Rivers, and in Wet Beaver Creek 
(Girmendonk and Young 1997, pp. 21, 25, 34; Voeltz 2002, p. 71; Bryan 
and Hyatt 2004, p. 3). Based on the best available information, we 
consider 13 populations to be lacking recruitment, and are thus 
``unstable-threatened.'' Also, there are nine populations for which we 
have limited status information and must consider ``unknown.'' Since 
roundtail chubs appear to live 5 to 7 years (Bestgen 1985, pp. 72-75; 
Brouder et al. 2000, p. 10; Brouder 2005, p. 866), total recruitment 
failure over a 10-year timeframe could extirpate a population. Because 
this is a relatively short period of time (compared to longer-lived 
species like the razorback sucker or bonytail), recruitment failure may 
be difficult to detect without significant monitoring efforts. 
Recruitment failure is particularly apparent in areas where habitat 
remains structurally intact, but where nonnative species maintain 
stable populations and native species persist at low levels. In Fossil 
Creek, a restoration effort in 2004 created a nonnative fish barrier 
and renovated 9.5 mi (15.3 km) of stream (U.S. Forest Service 2004, p. 
9), which removed all nonnative fish species, which were previously 
abundant, from Fossil Creek. Roundtail chub abundance increased 
dramatically after the restoration effort, illustrating clearly the 
significance of predation by and competition from nonnative fish 
species on limiting recruitment and abundance of the chub populations 
(Marks et al. in press, pp. 22-24). The observed effects of nonnative 
species on age-class distribution and recruitment are an important 
influence on the maintenance of current populations to be considered in 
our evaluation of the foreseeable future for this species.
    Predicting how current populations will fare over time is 
confounded by a lack of monitoring data and population and survivorship 
estimates. Although roundtail chub has persisted in many currently 
occupied locations for some time, there is little information on status 
over time, with often only one or two surveys to determine status. 
There is no status information available for one third of the 
populations. Of the remainder, many appear to be in a downward trend. 
Voeltz (2002) found that roundtail chub was extirpated from the Little 
Colorado River, Bill Williams River, Big Sandy River, Lower Gila River, 
San Pedro River, San Francisco River, Dry Beaver Creek, Zuni River, and 
Blue River (Voeltz 2002; see Table 2). All of these extirpated 
populations experienced reductions in flow, and many of the remaining 
populations are subjected to this threat. All of the remaining 
established populations are also subject to the threat of nonnative 
species with the exception of Fossil Creek, Ash Creak, and Roundtree 
Canyon. Generally, population trends appear to be declining throughout 
the lower Colorado River basin (Voeltz 2002, p. 85; Cantrell 2009, pp. 
10-11). Few efforts specifically examining trend have been conducted; 
two population estimate studies conducted for the species in the lower 
Colorado River basin indicated a declining trend (Brouder et al. 2000, 
p. 8-9; Bryan and Hyatt 2004, p. 3). For the lone ``stable-secure'' 
population, a recently completed study of Fossil Creek indicates a 
significant increase in abundance of roundtail chub as a result of flow 
increases and nonnative species removal (Marks et al. in press).
    We conclude that remaining populations are subject to a high risk 
of extirpation, given that: (1) Roundtail chub have a relatively high 
risk of localized extirpation due to habitat fragmentation (Fagan et 
al. 2002, p. 3254); (2) remaining populations are highly vulnerable to 
the effects of threats discussed in detail in Factors A through E 
above; (3) the significant threat of predation from nonnative fish 
species; (4) nonnative species show an alarming trend of eventually 
completely overtaking native species where they co-occur (Marsh and 
Pacey 2005, p. 59); (5) all but three existing established population 
of roundtail chub is believed to contain nonnative fish species (Voeltz 
2002); (6) the few existing studies of population trend and overall 
status assessments indicate a continuing decline in abundance, likely 
due to low recruitment as a result of predation from nonnative fishes 
(Voeltz 2002, pp. 83-88; Bryan and Hyatt, 2004, pp. 3, 12-13); and (7) 
many threats are projected to increase over time, including those most 
detrimental to the long-term viability of the DPS, such as the 
continued proliferation of nonnative species, and projected increases 
in human population and water use, both of which are likely to be 
exacerbated by the environmental effects resulting from climate change.

Finding

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
faced by the lower Colorado River basin roundtail chub. We reviewed the 
petition, information available in our files, and other published and 
unpublished information submitted to us by the public following our 90-
day petition finding, and consulted with recognized roundtail chub 
experts and other Federal and State resource agencies. On the basis of 
the best scientific and commercial information available, we find that 
the population segment satisfies the discreteness and significance 
elements of the DPS policy, and therefore qualifies as a DPS under our 
policy. We further find that listing the lower Colorado River basin DPS 
of roundtail chub is warranted. However, listing the lower Colorado 
River basin DPS of roundtail chub is precluded by higher priority 
listing actions at this time, as discussed in the Preclusion and 
Expeditious Progress section below.
    In making this finding, we recognize that there have been declines 
in the distribution and abundance of the roundtail chub, primarily 
attributed to the introduction of and subsequent predation by nonnative 
fishes, as documented in the body of scientific research on the 
distributions and impact of introduced fishes in relation to the 
roundtail chub. Direct predation by nonnative fishes on this species 
has resulted in rangewide population declines and local extirpations. 
Because nonnative species are present in all but one of the remaining 
established populations of this species, we conclude that remaining 
populations are at risk of declines and extirpation as a result of 
predation by nonnative species. Furthermore, the result of the past 
effects of these threats is that many of the remaining populations are 
fragmented and isolated, making them vulnerable to further declines and 
local extirpations from other factors (Fagan et al. 2002, p. 3250). 
Populations that go extinct following habitat fragmentation and 
population isolation are unlikely to be naturally recolonized due to 
both the isolation from, and lack of connectivity to, potential source 
populations.
    The isolation of remaining roundtail chub populations and habitat 
fragmentation as a result of nonnative fish introductions and habitat 
alteration has made remaining populations vulnerable to extinction from 
stochastic events. Stochastic events such as fire have only recently 
been recognized as an important factor in the decline of this species 
(Dunham et al. 2003, p. 183; Rinne 2004, p. 151). Other factors include 
parasitism and the inadequacy of existing regulatory mechanisms. These 
factors may contribute to declines

[[Page 32383]]

or extirpations of roundtail chub. In addition, these factors are 
exacerbated by the effects that have been caused by nonnative fishes. 
Also, a significant new threat appears to be environmental changes that 
result from climate change, which may have the potential to drastically 
reduce existing habitat through further stream dewatering, as well as 
result in habitat change by, for example, increasing water temperatures 
that will aid the spread and establishment of nonnative predators and 
parasites.
    A number of habitat altering land uses further threaten remaining 
populations of roundtail chub. These include dams, diversions, and 
groundwater withdrawal; livestock grazing; logging, fuel wood cutting, 
mining, and channelization; road construction, use, and maintenance; 
urban and rural development; recreation; and high-intensity wildfires. 
These threats negatively impact the rivers, streams, and riparian 
habitats that are essential for the survival of the roundtail chub. 
These threats have been documented historically, are either ongoing or 
likely to occur throughout the range of the roundtail chub in the lower 
Colorado River basin, and will reduce the suitability of roundtail chub 
habitat as cover for protection from predators, as a foraging area, and 
as spawning and nursery areas. Despite the conservation actions 
discussed above, the dewatering of aquatic habitats in the arid lower 
Colorado River basin poses a significant threat to all native fish of 
the region, including roundtail chub. All of these threats are 
anthropogenic and can be expected to continue, if not increase, given 
the predictions for increases in human population in the region.
    Efforts to improve the status of the roundtail chub in the lower 
Colorado River basin began in earnest in 2006. These conservation 
efforts, notably the Arizona Agreement and New Mexico Plan, include 
many actions to stabilize populations, establish new populations, 
increase the range of the species, and ameliorate threats. The 
conservation agreements have met with some success in this regard. Two 
populations have been created, as have two refuge populations and a 
refuge-broodstock population at a hatchery. Efforts to purchase land 
and water rights to reduce threats to habitat have met with some 
limited success. These conservation efforts can conserve the roundtail 
chub if fully implemented. Currently, however, they are in the early 
stages of implementation.

Preclusion and Expeditious Progress

    Preclusion is a function of the listing priority of a species in 
relation to the resources that are available and competing demands for 
those resources. Thus, in any given fiscal year (FY), multiple factors 
dictate whether it will be possible to undertake work on a proposed 
listing regulation or whether promulgation of such a proposal is 
warranted but precluded by higher- priority listing actions.
    The resources available for listing actions are determined through 
the annual Congressional appropriations process. The appropriation for 
the Listing Program is available to support work involving the 
following listing actions: proposed and final listing rules; 90-day and 
12-month findings on petitions to add species to the Lists of 
Endangered and Threatened Wildlife and Plants (Lists) or to change the 
status of a species from threatened to endangered; annual 
determinations on prior ``warranted but precluded'' petition findings 
as required under section 4(b)(3)(C)(i) of the Act; proposed and final 
rules designating critical habitat; and litigation-related, 
administrative, and program management functions (including preparing 
and allocating budgets, responding to Congressional and public 
inquiries, and conducting public outreach regarding listing and 
critical habitat). The work involved in preparing various listing 
documents can be extensive and may include, but is not limited to: 
gathering and assessing the best scientific and commercial data 
available and conducting analyses used as the basis for our decisions; 
writing and publishing documents; and obtaining, reviewing, and 
evaluating public comments and peer review comments on proposed rules 
and incorporating relevant information into final rules. The number of 
listing actions that we can undertake in a given year also is 
influenced by the complexity of those listing actions; that is, more 
complex actions generally are more costly. For example, during the past 
several years, the cost (excluding publication costs) for preparing a 
12-month finding, without a proposed rule, has ranged from 
approximately $11,000 for one species with a restricted range and 
involving a relatively uncomplicated analysis to $305,000 for another 
species that is wide-ranging and involving a complex analysis.
    We cannot spend more than is appropriated for the Listing Program 
without violating the Anti-Deficiency Act (see 31 U.S.C. 
1341(a)(1)(A)). In addition, in FY 1998 and for each fiscal year since 
then, Congress has placed a statutory cap on funds which may be 
expended for the Listing Program, equal to the amount expressly 
appropriated for that purpose in that fiscal year. This cap was 
designed to prevent funds appropriated for other functions under the 
Act (for example, recovery funds for removing species from the Lists), 
or for other Service programs, from being used for Listing Program 
actions (see House Report 105-163, 105th Congress, 1st Session, July 1, 
1997).
    Recognizing that designation of critical habitat for species 
already listed would consume most of the overall Listing Program 
appropriation, Congress also put a critical habitat subcap in place in 
FY 2002 and has retained it each subsequent year to ensure that some 
funds are available for other work in the Listing Program: ``The 
critical habitat designation subcap will ensure that some funding is 
available to address other listing activities'' (House Report No. 107-
103, 107th Congress, 1st Session, June 19, 2001). In FY 2002 and each 
year until FY 2006, the Service has had to use virtually the entire 
critical habitat subcap to address court-mandated designations of 
critical habitat, and consequently none of the critical habitat subcap 
funds have been available for other listing activities. In FY 2007, we 
were able to use some of the critical habitat subcap funds to fund 
proposed listing determinations for high-priority candidate species. In 
FY 2008, while we were unable to use any of the critical habitat subcap 
funds to fund proposed listing determinations, we did use some of this 
money to fund the critical habitat portion of some proposed listing 
determinations, so that the proposed listing determination and proposed 
critical habitat designation could be combined into one rule, thereby 
being more efficient in our work. In FY 2009, we anticipate being able 
to do the same.
    Thus, through the listing cap, the critical habitat subcap, and the 
amount of funds needed to address court-mandated critical habitat 
designations, Congress and the courts have in effect determined the 
amount of money available for other listing activities. Therefore, the 
funds in the listing cap, other than those needed to address court-
mandated critical habitat for already listed species, set the limits on 
our determinations of preclusion and expeditious progress.
    Congress also recognized that the availability of resources was the 
key element in deciding whether, when making a 12-month petition 
finding, we would prepare and issue a listing proposal or instead make 
a ``warranted

[[Page 32384]]

but precluded'' finding for a given species. The Conference Report 
accompanying Public Law 97-304, which established the current statutory 
deadlines and the warranted-but-precluded finding, states (in a 
discussion on 90-day petition findings that by its own terms also 
covers 12-month findings) that the deadlines were ``not intended to 
allow the Secretary to delay commencing the rulemaking process for any 
reason other than that the existence of pending or imminent proposals 
to list species subject to a greater degree of threat would make 
allocation of resources to such a petition [that is, for a lower-
ranking species] unwise.''
    In FY 2009, expeditious progress is that amount of work that can be 
achieved with $8,808,000, which is the amount of money that Congress 
appropriated for the Listing Program (that is, the portion of the 
Listing Program funding not related to critical habitat designations 
for species that are already listed). Our process is to make our 
determinations of preclusion on a nationwide basis to ensure that the 
species most in need of listing will be addressed first and also 
because we allocate our listing budget on a nationwide basis. The 
$8,808,000 is being used to fund work in the following categories: 
compliance with court orders and court-approved settlement agreements 
requiring that petition findings or listing determinations be completed 
by a specific date; section 4 (of the Act) listing actions with 
absolute statutory deadlines; essential litigation-related, 
administrative, and listing program management functions; and high-
priority listing actions for some of our candidate species. The 
allocations for each specific listing action are identified in the 
Service's FY 2009 Allocation Table (part of our administrative record).
    In FY 2007, we had more than 120 species with an LPN of 2, based on 
our September 21, 1983, guidance for assigning an LPN for each 
candidate species (48 FR 43098). Using this guidance, we assign each 
candidate an LPN of 1 to 12, depending on the magnitude of threats 
(high vs. moderate to low), immediacy of threats (imminent or 
nonimminent), and taxonomic status of the species (in order of 
priority: monotypic genus (a species that is the sole member of a 
genus); species; or part of a species (subspecies, distinct population 
segment, or significant portion of the range)). The lower the listing 
priority number, the higher the listing priority (that is, a species 
with an LPN of 1 would have the highest listing priority). Because of 
the large number of high-priority species, we further ranked the 
candidate species with an LPN of 2 by using the following extinction-
risk type criteria: International Union for the Conservation of Nature 
and Natural Resources (IUCN) Red list status/rank, Heritage rank 
(provided by NatureServe), Heritage threat rank (provided by 
NatureServe), and species currently with fewer than 50 individuals, or 
4 or fewer populations. Those species with the highest IUCN rank 
(critically endangered), the highest Heritage rank (G1), the highest 
Heritage threat rank (substantial, imminent threats), and currently 
with fewer than 50 individuals, or fewer than 4 populations, comprised 
a list of approximately 40 candidate species (``Top 40''). These 40 
candidate species have had the highest priority to receive funding to 
work on a proposed listing determination. As we work on proposed and 
final listing rules for these 40 candidates, we are applying the 
ranking criteria to the next group of candidates with LPN of 2 and 3 to 
determine the next set of highest priority candidate species.
    To be more efficient in our listing process, as we work on proposed 
rules for these species in the next several years, we are preparing 
multi-species proposals when appropriate, and these may include species 
with lower priority if they overlap geographically or have the same 
threats as a species with an LPN of 2. In addition, available staff 
resources are also a factor in determining high-priority species 
provided with funding. Finally, proposed rules for reclassification of 
threatened species to endangered are lower priority, because as listed 
species, they are already afforded the protection of the Act and 
implementing regulations.
    We assigned the lower Colorado River basin DPS of the roundtail 
chub an LPN of 9, based on our finding that the subspecies faces 
threats that are imminent and of moderate magnitude, including the 
present or threatened destruction, modification or curtailment of its 
habitat; the impacts of nonnative species; and the inadequacy of 
existing regulatory mechanisms. We consider the threat magnitude 
moderate because, while all populations are experiencing threats, the 
populations occur in multiple watersheds, and the threats acting on the 
DPS are not occurring uniformly throughout the range of the species; 
therefore not all populations are likely to be impacted simultaneously 
by any of the known threats. Additionally, the existence of 
conservation agreements has resulted in the implementation of actions 
to improve the status of the DPS and reduce the severity of threats. We 
anticipate that these conservation agreements will continue to benefit 
the species with additional actions to improve status and reduce or 
eliminate threats. Although implemented too recently to assess, recent 
efforts to create new populations of the DPS in relatively threat-free 
habitats may prove to be successful, and additional restoration efforts 
are being planned.
    We consider the threats imminent because they are currently 
occurring in all of the existing populations. Under the 1983 Guidelines 
(48 FR 43098), a subspecies or DPS receives a lower priority than a 
full species and a full species receives a lower priority than a 
monotypic genus, thus a DPS facing imminent moderate-magnitude threats 
is assigned an LPN of 9. Therefore, work on a proposed listing 
determination for the lower Colorado River basin DPS of roundtail chub 
is precluded by work on higher priority candidate species (i.e., 
entities with LPN of 8 or lower); listing actions with absolute 
statutory, court ordered, or court-approved deadlines; and final 
listing determinations for those species that were proposed for listing 
with funds from FY 2008. This work includes all the actions listed in 
the tables below under expeditious progress.
    As explained above, a determination that listing is warranted but 
precluded must also demonstrate that expeditious progress is being made 
to add or remove qualified species to and from the Lists of Endangered 
and Threatened Wildlife and Plants. (Although we do not discuss it in 
detail here, we are also making expeditious progress in removing 
species from the list under the Recovery program, which is funded by a 
separate line item in the budget of the Endangered Species Program. As 
explained above in our description of the statutory cap on Listing 
Program funds, the Recovery Program funds and actions supported by them 
cannot be considered in determining expeditious progress made in the 
Listing Program.) As with our ``precluded'' finding, expeditious 
progress in adding qualified species to the Lists is a function of the 
resources available and the competing demands for those funds. Given 
that limitation, we find that we are making progress in FY 2009 in the 
Listing Program. This progress included preparing and publishing the 
following determinations:

[[Page 32385]]



                                        FY 2009 Completed Listing Actions
----------------------------------------------------------------------------------------------------------------
      Publication date                 Title                   Actions                      FR pages
----------------------------------------------------------------------------------------------------------------
10/15/2008..................  90-Day Finding on a      Notice of 90-day        73 FR 61007-61015
                               Petition To List the     Petition Finding,
                               Least Chub               Substantial.
10/21/2008..................  Listing 48 Species on    Proposed Listing,       73 FR 62591-62742
                               Kauai as Endangered      Endangered; Proposed
                               and Designating          Critical Habitat.
                               Critical Habitat
10/24/2008..................  90[dash]Day Finding on   Notice of 90-day        73 FR 63421-63424
                               a Petition to List the   Petition Finding, Not
                               Sacramento Valley        substantial.
                               Tiger Beetle as
                               Endangered
10/28/2008..................  90-Day Finding on a      Notice of 90-day        73 FR 63919-63926
                               Petition To List the     Petition Finding,
                               Dusky Tree Vole as       Substantial.
                               Threatened or
                               Endangered
11/25/2008..................  12-Month Finding on a    Notice of 12-month      73 FR 71787-71826
                               Petition To List the     petition finding,
                               Northern Mexican         Warranted but
                               Gartersnake as           precluded.
                               Threatened or
                               Endangered With
                               Critical Habitat;
                               Proposed Rule
12/02/2008..................  90-Day Finding on a      Notice of 90-day        73 FR 73211-73219
                               Petition To List the     Petition Finding,
                               Black-tailed Prairie     Substantial.
                               Dog as Threatened or
                               Endangered
12/05/2008..................  90-Day Finding on a      Notice of 90-day        73 FR 74123-74129
                               Petition To List the     Petition Finding,
                               Sacramento Mountains     Substantial.
                               Checkerspot Butterfly
                               as Endangered with
                               Critical Habitat
12/18/2008..................  90-Day Finding on a      Notice of 90-day        73 FR 76990-76994
                               Petition to Change the   Petition Finding,
                               Listing Status of the    Substantial.
                               Canada Lynx
1/06/2009...................  Partial 90-Day Finding   Notice of 90-day        74 FR 419-427
                               on a Petition To List    Petition Finding, Not
                               475 Species in the       substantial.
                               Southwestern United
                               States as Threatened
                               or Endangered With
                               Critical Habitat
2/05/2009...................  Partial 90-Day Finding   Notice of 90-day        74 FR 6122-6128
                               on a Petition To List    Petition Finding, Not
                               206 Species in the in    substantial.
                               the Midwest and
                               Western United States
                               as Threatened or
                               Endangered With
                               Critical Habitat
2/10/2009...................  90-Day Finding on a      Notice of 90-day        74 FR 6558-6563
                               Petition To List the     Petition Finding,
                               Wyoming Pocket Gopher    Substantial.
                               as Threatened or
                               Endangered With
                               Critical Habitat
3/17/2009...................  Listing Phyllostegia     Final Listing           74 FR 11319-11327
                               hispida as Endangered    Endangered.
                               Throughout Its Range
3/25/2009...................  12-Month Finding on a    Notice of 12-month      74 FR 12931-12968
                               Petition to List the     petition finding,
                               Yellow-Billed Loon as    Warranted but
                               Threatened or            precluded.
                               Endangered
4/09/2009...................  12-Month Finding on a    Notice of 12-month      74 FR 16169-16175
                               Petition to List the     petition finding, Not
                               San Francisco Bay-       warranted.
                               Delta Population of
                               the Longfin Smelt as
                               Endangered
4/22/2009...................  90-Day Finding on a      Notice of 90-day        74 FR 18336-18341
                               Petition To List the     Petition Finding,
                               Tehachapi Slender        Substantial.
                               Salamander as
                               Threatened or
                               Endangered
5/07/2009...................  90-Day Finding on a      Notice of 90-day        74 FR 21301-21310
                               Petition To List the     Petition Finding,
                               American Pika as         Substantial.
                               Threatened or
                               Endangered with
                               Critical Habitat
5/-/2009....................  12-Month Finding on a    Notice of 12-month      74 FR 23376 23376-23388
                               Petition to List the     petition finding, Not
                               Coaster Brook Trout as   warranted.
                               Endangered
6/09/2009...................  90-Day Finding on a      Notice of 90-day        74 FR 27266-27271
                               Petition to List         Petition Finding, Not
                               Oenothera acutissima     substantial.
                               as Threatened or
                               Endangered
----------------------------------------------------------------------------------------------------------------

    Our expeditious progress also included work on listing actions, 
which we funded in FY 2009 but have not yet been completed to date. 
These actions are listed below. Actions in the top section of the table 
are being conducted under a deadline set by a court. Actions in the 
middle section of the table are being conducted to meet statutory 
timelines, that is, timelines required under the Act. Actions in the 
bottom section of the table are high priority listing actions. These 
actions include work primarily on species with an LPN of 2, and 
selection of these species is partially based on available staff 
resources, and when appropriate, include species with a lower priority 
if they overlap geographically or have the same threats as the species 
with the high priority. Including these species together in the same 
proposed rule results in considerable savings in time and funding, when 
compared to preparing separate proposed rules for each of them in the 
future.

             Actions Funded in FY 2009 But Not Yet Completed
------------------------------------------------------------------------
            Species                              Action
------------------------------------------------------------------------
           Actions Subject to Court Order/Settlement Agreement
------------------------------------------------------------------------
Slickspot peppergrass.........  Final listing determination.
Coastal cutthroat trout.......  Final listing determination.
Mono basin sage-grouse........  12-month petition finding.
Sacramento Mtns. checkerspot    12-month petition finding.
 butterfly.

[[Page 32386]]

 
SW Bald eagle population......  12-month petition finding.
Black-tailed prairie dog......  12-month petition finding.
Lynx (include New Mexico in     12-month petition finding.
 listing.).
White-tailed prairie dog......  12-month petition finding.
Big Lost River whitefish......  12-month petition finding.
Hermes copper butterfly.......  90-day petition finding.
Thorne's hairstreak butterfly.  90-day petition finding.
------------------------------------------------------------------------
                    Actions With Statutory Deadlines
------------------------------------------------------------------------
48 Kauai species..............  Final listing determination.
Black-footed albatross........  12-month petition finding.
Mount Charleston blue           12-month petition finding.
 butterfly.
Goose Creek milk-vetch........  12-month petition finding.
Mojave fringe-toed lizard \1\.  12-month petition finding.
Pygmy rabbit (rangewide) \1\..  12-month petition finding.
Kokanee--Lake Sammamish         12-month petition finding.
 population \1\.
Ashy storm petrel.............  12-month petition finding.
Delta smelt (uplisting).......  12-month petition finding.
Cactus ferruginous pygmy owl    12-month petition finding.
 \1\.
Tucson shovel-nosed snake \1\.  12-month petition finding.
Northern leopard frog.........  12-month petition finding.
Tehachapi slender salamander..  12-month petition finding.
Northern leopard frog.........  90-day petition finding.
4 subspecies of                 90-day petition finding.
 Pseudocopaeodes enunus.
Southeastern pop snowy plover   90-day petition finding.
 & wintering pop. of piping
 plover.
Berry Cave salamander \1\.....  90-day petition finding.
Ozark chinquapin \1\..........  90-day petition finding.
Smooth-billed ani.............  90-day petition finding.
Bay Springs salamander \1\....  90-day petition finding.
Mojave ground squirrel \1\....  90-day petition finding.
Llanero coqui.................  90-day petition finding.
Gopher tortoise--eastern        90-day petition finding.
 population.
Mojave ground squirrel........  90-day petition finding.
Pacific walrus................  90-day petition finding.
32 species of snails and slugs  90-day petition finding.
Calopogon oklahomensis........  90-day petition finding.
Susan's purse-making caddisfly  90-day petition finding.
Striped newt..................  90-day petition finding.
American dipper--Black Hills    90-day petition finding.
 population.
Sprague's pipit...............  90-day petition finding.
Southern hickorynut...........  90-day petition finding.
5 Southwest mussel species....  90-day petition finding.
Sonoran desert tortoise.......  90-day petition finding.
Chihuahua scarfpea............  90-day petition finding.
Jemez Mtns. salamander........  90-day petition finding.
White-sided jackrabbit........  90-day petition finding.
Wrights marsh thistle.........  90-day petition finding.
White-bark pine...............  90-day petition finding.
Puerto Rico harlequin.........  90-day petition finding.
Fisher--Northern Rocky Mtns.    90-day petition finding.
 population.
42 snail species (Nevada &      90-day petition finding.
 Utah).
HI yellow-faced bees..........  90-day petition finding.
206 species (partially          90-day petition finding.
 completed).
475 Southwestern species        90-day petition finding.
 (partially completed).
------------------------------------------------------------------------
                    High Priority Listing Actions \3\
------------------------------------------------------------------------
19 Oahu candidate species (16   Proposed listing.
 plants, 3 damselflies) (15
 with LPN = 2, 3 with LPN = 3,
 1 with LPN = 9).
2 HI damselflies (LPN = 2)....  Proposed listing.
17 Maui-Nui candidate species   Proposed listing.
 (14 plants, 3 tree snails)
 (12 with LPN = 2, 3 with LPN
 = 3, 3 with LPN = 8).
Sand dune lizard (LPN = 2)....  Proposed listing.
2 Arizona springsnails          Proposed listing.
 (Pyrgulopsis bernadina (LPN =
 2), Pyrgulopsis trivialis
 (LPN = 2)).
2 New Mexico springsnails       Proposed listing.
 (Pyrgulopsis chupaderae (LPN
 = 2), Pyrgulopsis thermalis
 (LPN = 11)).
2 mussels (rayed bean (LPN =    Proposed listing.
 2), snuffbox No LPN).
2 mussels (sheepnose (LPN =     Proposed listing.
 2), spectaclecase (LPN = 4),).
Ozark hellbender \2\ (LPN = 3)  Proposed listing.
3 southeast aquatic species     Proposed listing.
 \1\ (Georgia pigtoe,
 interrupted rocksnail, rough
 hornsnail) (all with LPN = 2).
Altamaha spinymussel (LPN = 2)  Proposed listing.
5 southeast fish (rush darter   Proposed listing.
 (LPN = 2), chucky madtom (LPN
 = 2), yellowcheek darter (LPN
 = 2), Cumberland darter (LPN
 = 5), laurel dace (LPN = 5)).

[[Page 32387]]

 
8 southeast mussels (southern   Proposed listing.
 kidneyshell (LPN = 2), round
 ebonyshell (LPN = 2), Alabama
 pearshell (LPN = 2), southern
 sandshell (LPN = 5), fuzzy
 pigtoe (LPN = 5), Choctaw
 bean (LPN = 5), narrow pigtoe
 (LPN = 11), and tapered
 pigtoe (LPN = 11)).
3 Colorado plants (Pagosa       Proposed listing.
 skyrocket (Ipomopsis
 polyantha) (LPN = 2),
 Parchute beardtongue
 (Penstemon debilis) (LPN =
 2), Debeque phacelia
 (Phacelia submutica) (LPN =
 8)).
Casey's june beetle (LPN = 2).  Proposed listing.
------------------------------------------------------------------------
\1\ Funds for listing actions for these species were provided in
  previous FYs.
\2\ We funded a proposed rule for this subspecies with an LPN of 3 ahead
  of other species with LPN of 2, because the threats to the species
  were so imminent and of a high magnitude that we considered emergency
  listing if we were unable to fund work on a proposed listing rule in
  FY 2008.
\3\ Funds for these high priority listing actions were provided in FY
  2008 and 2009.

    We have endeavored to make our listing actions as efficient and 
timely as possible, given the requirements of the relevant law and 
regulations, and constraints relating to workload and personnel. We 
are continually considering ways to streamline processes or achieve 
economies of scale, such as by batching related actions together. 
Given our limited budget for implementing section 4 of the Act, 
these actions described above collectively constitute expeditious 
progress.

    The lower Colorado River basin DPS of roundtail chub will be added 
to the list of candidate species upon publication of this 12-month 
finding. We will continue to monitor the status of this species as new 
information becomes available. This review will determine if a change 
in status is warranted, including the need to make prompt use of 
emergency listing procedures.
    We intend that any proposed listing action for the lower Colorado 
River basin DPS of roundtail chub will be as accurate as possible. 
Therefore, we will continue to accept additional information and 
comments from all concerned governmental agencies, the scientific 
community, industry, or any other interested party concerning this 
finding.

References Cited

    A complete list of all references cited in this document is 
available upon request from the Field Supervisor at the Arizona 
Ecological Services Office (see ADDRESSES section).

Author

    The primary authors of this document are the staff members of the 
Arizona Ecological Services Office (see ADDRESSES section).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: June 24, 2009.
Marvin E. Moriarty,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E9-15828 Filed 7-6-09; 8:45 am]
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