32352 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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. 

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 

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

32354 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 PeaksMogollon Rim Section of the ArizonaNew Mexico Mountains Semi-DesertOpen 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-DesertConiferous 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). 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 32355 

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 olivegray 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 (°C) (32 to 90 degrees 

Fahrenheit (°F)) (Bestgen 1985, p. 14). 

Carveth et al. (2006, p. 1435) reported 

the upper thermal tolerance of roundtail 

chub to be 36.6 °C (97.9 °F); spawning 

has been documented from 14 to 24 °C 

(57 to 75 °F) (Bestgen 1985, p. 14; 

Kaeding et al. 1990, p. 139; Brouder et 

32356 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 peerreviewed 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 streamspecific locality. A population was 

considered ‘‘stable-secure,’’ ‘‘stablethreatened,’’ 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 ‘‘unstablethreatened,’’ 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 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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 ‘‘stablesecure’’ 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] 

Location Current 

status Regional historical or 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. 

32358 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

TABLE 2—SUMMARY OF ROUNDTAIL CHUB STATUS AND THREATS BY STREAM REACH—Continued 

[Voeltz 2002, Cantrell 2009, service files] 

Location Current 

status Regional historical or current threats 

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. 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 32359 

TABLE 2—SUMMARY OF ROUNDTAIL CHUB STATUS AND THREATS BY STREAM REACH—Continued 

[Voeltz 2002, Cantrell 2009, service files] 

Location Current 

status Regional historical or current threats 

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). 

32360 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 

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

32362 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 late1880s 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 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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 °C (50 °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 °C (95 °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 restrotation 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, 

32364 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 °C (0.5 °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 nutrientenriched 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 

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

32366 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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; Me ́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 lowintensity 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, 

32368 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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; 

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

32370 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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-andrelease 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 

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

32372 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 welladapted 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 rangewide declines that prevent or negate 

recovery efforts from being 

implemented or being successful 

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

32374 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 dieoff 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 

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

32376 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 SRPowned 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 cooccurrence 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 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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 Rangewide 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 stablesecure 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 mid21st 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 

32378 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 

°C (77–86 °F) (Granath and Esch 1983, 

p. 1116), and optimal anchorworm 

temperatures are 23–30 °C (73–86 °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) 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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 GilaCliff 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 goodfaith 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). 

32380 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

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 ‘‘stablethreatened’’ and two are ‘‘unstablethreatened.’’ 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 ‘‘stablethreatened’’ and one is ‘‘unstablethreatened.’’ 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 ‘‘stablethreatened’’ 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 

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

32382 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

Voeltz (2002, p. 5) defined ‘‘unstablethreatened’’ 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 ‘‘stablesecure’’ 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 cooccur (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 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 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 highintensity 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 higherpriority 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 courtmandated 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 courtmandated 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 

32384 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

but precluded’’ finding for a given 

species. The Conference Report 

accompanying Public Law 97–304, 

which established the current statutory 

deadlines and the warranted-butprecluded 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 highpriority 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: 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 32385 

FY 2009 COMPLETED LISTING ACTIONS

Publication date Title Actions FR pages 

10/15/2008 ........ 90-Day Finding on a Petition To List the Least 

Chub 

Notice of 90-day Petition Finding, Substantial ..... 73 FR 61007–61015 

10/21/2008 ........ Listing 48 Species on Kauai as Endangered and 

Designating Critical Habitat 

Proposed Listing, Endangered; Proposed Critical 

Habitat.

73 FR 62591–62742 

10/24/2008 ........ 90-Day Finding on a Petition to List the Sacramento Valley Tiger Beetle as Endangered Notice of 90-day Petition Finding, Not substantial 73 FR 63421–63424 

10/28/2008 ........ 90-Day Finding on a Petition To List the Dusky 

Tree Vole as Threatened or Endangered 

Notice of 90-day Petition Finding, Substantial ..... 73 FR 63919–63926 

11/25/2008 ........ 12-Month Finding on a Petition To List the Northern Mexican Gartersnake as Threatened or 

Endangered With Critical Habitat; Proposed 

Rule 

Notice of 12-month petition finding, Warranted 

but precluded.

73 FR 71787–71826 

12/02/2008 ........ 90-Day Finding on a Petition To List the Blacktailed Prairie Dog as Threatened or Endangered Notice of 90-day Petition Finding, Substantial ..... 73 FR 73211–73219 

12/05/2008 ........ 90-Day Finding on a Petition To List the Sacramento Mountains Checkerspot Butterfly as 

Endangered with Critical Habitat 

Notice of 90-day Petition Finding, Substantial ..... 73 FR 74123–74129 

12/18/2008 ........ 90-Day Finding on a Petition to Change the Listing Status of the Canada Lynx Notice of 90-day Petition Finding, Substantial ..... 73 FR 76990–76994 

1/06/2009 .......... Partial 90-Day Finding on a Petition To List 475 

Species in the Southwestern United States as 

Threatened or Endangered With Critical Habitat 

Notice of 90-day Petition Finding, Not substantial 74 FR 419–427 

2/05/2009 .......... Partial 90-Day Finding on a Petition To List 206 

Species in the in the Midwest and Western 

United States as Threatened or Endangered 

With Critical Habitat 

Notice of 90-day Petition Finding, Not substantial 74 FR 6122–6128 

2/10/2009 .......... 90-Day Finding on a Petition To List the Wyoming Pocket Gopher as Threatened or Endangered With Critical Habitat Notice of 90-day Petition Finding, Substantial ..... 74 FR 6558–6563 

3/17/2009 .......... Listing Phyllostegia hispida as Endangered 

Throughout Its Range 

Final Listing Endangered ...................................... 74 FR 11319–11327 

3/25/2009 .......... 12-Month Finding on a Petition to List the Yellow-Billed Loon as Threatened or Endangered Notice of 12-month petition finding, Warranted 

but precluded.

74 FR 12931–12968 

4/09/2009 .......... 12-Month Finding on a Petition to List the San 

Francisco Bay-Delta Population of the Longfin 

Smelt as Endangered 

Notice of 12-month petition finding, Not warranted.74 FR 16169–16175 

4/22/2009 .......... 90-Day Finding on a Petition To List the 

Tehachapi Slender Salamander as Threatened 

or Endangered 

Notice of 90-day Petition Finding, Substantial ..... 74 FR 18336–18341 

5/07/2009 .......... 90-Day Finding on a Petition To List the American Pika as Threatened or Endangered with 

Critical Habitat 

Notice of 90-day Petition Finding, Substantial ..... 74 FR 21301–21310 

5/-/2009 ............. 12-Month Finding on a Petition to List the Coaster Brook Trout as Endangered Notice of 12-month petition finding, Not warranted.74 FR 23376 23376– 

23388 

6/09/2009 .......... 90-Day Finding on a Petition to List Oenothera 

acutissima as Threatened or Endangered 

Notice of 90-day Petition Finding, Not substantial 74 FR 27266–27271 

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 butterfly ................................................................................................................. 12-month petition finding. 

32386 Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 

ACTIONS FUNDED IN FY 2009 BUT NOT YET COMPLETED—Continued 

Species Action 

SW Bald eagle population ....................................................................................................................................... 12-month petition finding. 

Black-tailed prairie dog ............................................................................................................................................ 12-month petition finding. 

Lynx (include New Mexico in listing.) ...................................................................................................................... 12-month petition finding. 

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 butterfly ............................................................................................................................... 12-month petition finding. 

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 population 1 .............................................................................................................. 12-month petition finding. 

Ashy storm petrel ..................................................................................................................................................... 12-month petition finding. 

Delta smelt (uplisting) .............................................................................................................................................. 12-month petition finding. 

Cactus ferruginous pygmy owl 1 .............................................................................................................................. 12-month petition finding. 

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 Pseudocopaeodes enunus ............................................................................................................ 90-day petition finding. 

Southeastern pop snowy plover & wintering pop. of piping plover ......................................................................... 90-day petition finding. 

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 population ....................................................................................................................... 90-day petition finding. 

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 population ................................................................................................................. 90-day petition finding. 

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. population ............................................................................................................... 90-day petition finding. 

42 snail species (Nevada & Utah) ........................................................................................................................... 90-day petition finding. 

HI yellow-faced bees ............................................................................................................................................... 90-day petition finding. 

206 species (partially completed) ............................................................................................................................ 90-day petition finding. 

475 Southwestern species (partially completed) ..................................................................................................... 90-day petition finding. 

High Priority Listing Actions 3

19 Oahu candidate species (16 plants, 3 damselflies) (15 with LPN = 2, 3 with LPN = 3, 1 with LPN = 9) ........ Proposed listing.

2 HI damselflies (LPN = 2) ...................................................................................................................................... Proposed listing. 

17 Maui-Nui candidate species (14 plants, 3 tree snails) (12 with LPN = 2, 3 with LPN = 3, 3 with LPN = 8) .... Proposed listing.

Sand dune lizard (LPN = 2) ..................................................................................................................................... Proposed listing. 

2 Arizona springsnails (Pyrgulopsis bernadina (LPN = 2), Pyrgulopsis trivialis (LPN = 2)) ................................... Proposed listing. 

2 New Mexico springsnails (Pyrgulopsis chupaderae (LPN = 2), Pyrgulopsis thermalis (LPN = 11)) ................... Proposed listing. 

2 mussels (rayed bean (LPN = 2), snuffbox No LPN) ............................................................................................ Proposed listing. 

2 mussels (sheepnose (LPN = 2), spectaclecase (LPN = 4),) ............................................................................... Proposed listing. 

Ozark hellbender 2 (LPN = 3) .................................................................................................................................. Proposed listing. 

3 southeast aquatic species 1 (Georgia pigtoe, interrupted rocksnail, rough hornsnail) (all with LPN = 2) ........... Proposed listing. 

Altamaha spinymussel (LPN = 2) ............................................................................................................................ Proposed listing. 

5 southeast fish (rush darter (LPN = 2), chucky madtom (LPN = 2), yellowcheek darter (LPN = 2), Cumberland 

darter (LPN = 5), laurel dace (LPN = 5)).

Proposed listing. 

Federal Register / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules 32387 

ACTIONS FUNDED IN FY 2009 BUT NOT YET COMPLETED—Continued 

Species Action 

8 southeast mussels (southern 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)).

Proposed listing. 

3 Colorado plants (Pagosa skyrocket (Ipomopsis polyantha) (LPN = 2), Parchute beardtongue (Penstemon 

debilis) (LPN = 2), Debeque phacelia (Phacelia submutica) (LPN = 8)).

Proposed listing. 

Casey’s june beetle (LPN = 2) ................................................................................................................................ Proposed listing. 

1Funds for listing actions for these species were provided in previous FYs. 

2We 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. 3Funds 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] 

BILLING CODE 4310–55–P