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[Federal Register Volume 76, Number 72 (Thursday, April 14, 2011)]
[Proposed Rules]
[Pages 20911-20918]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-9089]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2011-0018; MO92210-0-0008-B2]

Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Prairie Chub as Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of petition finding and initiation of status review.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the prairie chub (Macrhybopsis 
australis) as threatened or endangered under the Endangered Species Act 
of 1973, as amended (Act), and to designate critical habitat. The 
prairie chub is a fish endemic to the upper Red River basin in Oklahoma 
and Texas. Based on our review, we find that the petition presents 
substantial scientific or commercial information indicating that 
listing the prairie chub may be warranted. Therefore, with the 
publication of this notice, we are initiating a review of the status of 
the species to determine if listing the prairie chub is warranted. To 
ensure that this status review is comprehensive, we are requesting 
scientific and commercial data and other information regarding this 
species. Based on the status review, we will issue a 12-month finding 
on the petition, which will address whether the petitioned action is 
warranted, as provided in the Act.

DATES: To allow us adequate time to conduct this review, we request 
that we receive information on or before June 13, 2011. Please note 
that if you are using the Federal eRulemaking Portal (see ADDRESSES 
section, below), the deadline for submitting an electronic comment is 
11:59 p.m. Eastern Time on this date.

ADDRESSES: You may submit information by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. In 
the box that reads ``Enter Keyword or ID,'' enter the Docket number for 
this finding, which is [Docket No. FWS-R2-ES-2011-0018]. Check the box 
that reads ``Open for Comment/Submission,'' and then click the Search 
button. You should then see an icon that reads ``Submit a Comment.'' 
Please ensure that you have found the correct rulemaking before 
submitting your comment.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: [Docket No. FWS-R2-ES-2011-0018]; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.

We will post all information we receive on http://www.regulations.gov. 
This generally means that we will post any personal information you 
provide us (see the Request for Information section below for more 
details).

    After June 13, 2011, you must submit information directly to the 
Field Office (see FOR FURTHER INFORMATION CONTACT section below). 
Please note that we might not be able to address or incorporate 
information that we receive after the above requested date.

FOR FURTHER INFORMATION CONTACT: Dixie Bounds, Field Supervisor, U.S. 
Fish and Wildlife Service, Oklahoma Ecological Services Field Office, 
9014 East 21st Street, Tulsa, OK 74129, by telephone at 918-581-7458, 
or by facsimile at 918-581-7467. If you use a telecommunications device 
for the deaf (TDD), please call the Federal Information Relay Service 
(FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Request for Information

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly review the status of the species (status review). 
For the status review to be complete and based on the best available 
scientific and commercial information, we request information on the 
prairie chub from governmental agencies, Native American Tribes, the 
scientific community, industry, and any other interested parties. We 
seek information on:
    (1) The species' biology, range, and population trends, including:
    (a) Habitat requirements for feeding, breeding, and sheltering;
    (b) Genetics and taxonomy;
    (c) Historical and current range, including distribution patterns;
    (d) Historical and current population levels, and current and 
projected trends; and
    (e) Past and ongoing conservation measures for the species, its 
habitat, or both.
    (2) The factors that are the basis for making a listing 
determination for a species under section 4(a) of the Act (16 U.S.C. 
1531 et seq.), which are:
    (a) The present or threatened destruction, modification, or 
curtailment of its habitat or range;

[[Page 20912]]

    (b) Overutilization for commercial, recreational, scientific, or 
educational purposes;
    (c) Disease or predation;
    (d) The inadequacy of existing regulatory mechanisms; or
    (e) Other natural or manmade factors affecting its continued 
existence.
    If, after the status review, we determine that listing the prairie 
chub is warranted, we will propose critical habitat (see definition in 
section 3(5)(A) of the Act), under section 4 of the Act, to the maximum 
extent prudent and determinable at the time we propose to list the 
species. Therefore, within the geographical range currently occupied by 
the prairie chub, we request data and information on:
    (1) What may constitute ``physical or biological features essential 
to the conservation of the species'';
    (2) Where these features are currently found; and
    (3) Whether any of these features may require special management 
considerations or protection.
    In addition, we request data and information on ``specific areas 
outside the geographical area occupied by the species'' that are 
``essential to the conservation of the species.'' Please provide 
specific comments and information as to what, if any, critical habitat 
you think we should propose for designation if the species is proposed 
for listing, and why such habitat meets the requirements of section 4 
of the Act.
    Please include sufficient information with your submission (such as 
scientific journal articles or other publications) to allow us to 
verify any scientific or commercial information you include.
    Submissions merely stating support for or opposition to the action 
under consideration without providing supporting information, although 
noted, will not be considered in making a determination. Section 
4(b)(1)(A) of the Act directs that determinations as to whether any 
species is an endangered or threatened species must be made ``solely on 
the basis of the best scientific and commercial data available.''
    You may submit your information concerning this status review by 
one of the methods listed in the ADDRESSES section. If you submit 
information via http://www.regulations.gov, your entire submission--
including any personal identifying information--will be posted on the 
Web site. If you submit a hardcopy that includes personal identifying 
information, you may request at the top of your document that we 
withhold this personal identifying information from public review. 
However, we cannot guarantee that we will be able to do so. We will 
post all hardcopy submissions on http://www.regulations.gov.
    Information and supporting documentation that we received and used 
in preparing this 90-day finding are available for you to review at 
http://www.regulations.gov, or you may make an appointment during 
normal business hours at the U.S. Fish and Wildlife Service, Oklahoma 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Background

    Section 4(b)(3)(A) of the Act (16 U.S.C. 1533(b)(3)(A)) requires 
that we make a finding on whether a petition to list, delist, or 
reclassify a species presents substantial scientific or commercial 
information indicating that the petitioned action may be warranted. We 
are to base this finding on information provided in the petition, 
supporting information submitted with the petition, and information 
otherwise available in our files. To the maximum extent practicable, we 
are to make this finding within 90 days of our receipt of the petition 
and publish our notice of the finding promptly in the Federal Register.
    Our standard for substantial scientific or commercial information 
within the Code of Federal Regulations (CFR) with regard to a 90-day 
petition finding is ``that amount of information that would lead a 
reasonable person to believe that the measure proposed in the petition 
may be warranted'' (50 CFR 424.14(b)). If we find that substantial 
scientific or commercial information was presented, we are required to 
promptly conduct a species status review, which we subsequently 
summarize in our 12-month finding.

Petition History

    On January 25, 2010, we received a petition dated January 14, 2010, 
from WildEarth Guardians, requesting that the prairie chub be listed as 
threatened or endangered and that critical habitat be designated under 
the Act. The petition clearly identified itself as such and included 
the requisite identification information for the petitioner, as 
required by 50 CFR 424.14(a). In a July 19, 2010, letter to the 
petitioner, we responded that we reviewed the information presented in 
the petition and determined that issuing an emergency regulation 
temporarily listing the species under section 4(b)(7) of the Act was 
not warranted. We also stated that, due to court orders and judicially 
approved settlement agreements for other listing and critical habitat 
determinations under the Act that required nearly all of our listing 
and critical habitat funding for fiscal year 2010, we would not be able 
to further address the petition at that time, but would complete the 
action when workload and funding allowed. This finding addresses the 
petition.

Previous Federal Actions

    There have been no Federal actions specific to the prairie chub.

Species Information

Taxonomy and Description

    The prairie chub is a small fish that was originally described by 
Hubbs and Ortenberger (1929, pp. 23-28) from a collection in the Red 
River 10 to 14 kilometers (km) (6 to 9 miles (mi)) southwest of Hollis, 
Harmon County, Oklahoma. Until 2004, the prairie chub was treated as a 
single, wide-ranging, geographically variable species, referred to as 
Macrhybopsis aestivalis (Wallace 1980, p. 180; Eisenhour 2004, pp. 9-
10). An analysis of the species' morphology conducted by Eisenhour 
(2004, p. 13) resulted in the recognition of five species west of the 
Mississippi River within the Macrhybopsis complex: The prairie chub (M. 
australis) in the upper Red River drainage; the peppered chub (formerly 
Arkansas River speckled chub) (M. tetranema) in the upper Arkansas 
River drainage; the shoal chub (M. hyostoma) in the central and eastern 
United States; the speckled chub (M. aestivalis) from the Rio Grande 
River in Texas; and the burrhead chub (M. marconis), which occurs in 
the San Antonio and Guadalupe Rivers in Texas, with remnant populations 
possibly in the Edwards Plateau portion of the Colorado River (Miller 
and Robison 2004, pp. 126-127; Hubbs et al. 2008, p. 21).
    Even though there are morphological characteristics separating 
Macrhybopsis into five species, there are genetic similarities that 
dispute this species separation. Underwood et al. (2003, pp. 493, 497) 
examined genes in three of the western members of the Macrhybopsis 
complex and noted that the three forms of speckled chub occurring in 
the Red and Arkansas Rivers could possibly comprise a single species. 
Underwood et al. (2003, p. 297) suggested that the mixing of the 
species' genes through hybridization may be why the shoal chub (M. 
hyostoma) in the Red and Arkansas Rivers is genetically similar to the 
prairie chub (M. australis) in the Red River and the peppered chub (M. 
tetranema) in the Arkansas River (Underwood et al. 2003, p. 498). 
Further genetic studies are needed on all five species of Macrhybopsis 
west of the

[[Page 20913]]

Mississippi River to help resolve their genetic lineages.
    We accept the characterization of the prairie chub as a separate 
species with the scientific name Macrhybopsis australis because of 
research conducted by Eisenhour (2004, pp. 13, 28-31); this research 
has been accepted by the scientific community. The prairie chub is 
listed as a species in the Common and Scientific Names of Fishes, which 
was published by the American Fisheries Society in 2004.

Distribution

    The prairie chub is endemic to the upper Red River basin in 
Oklahoma and Texas. Based on information in the petition and readily 
available in our files, the species' current distribution appears to 
include the following rivers and streams: Elm Fork of the Red River, 
North Fork of the Red River downstream of Altus Lake, Salt Fork of the 
Red River, Prairie Dog Town Fork of the Red River, Buck Creek, Pease 
River, North Wichita River, South Wichita River, Mud Creek, Bitter 
Creek, Gypsum Boggy Creek, Sandy (Lebos) Creek, Beaver Creek, and the 
Red River proper upstream of Lake Texoma (Wilde et al. 1996, pp. 26-55; 
Underwood 2003, p. 499; Eisenhour 2004, pp. 30, 40-41; Miller and 
Robison 2004, pp. 126-127). The species is presumed extirpated in the 
Washita River (Miller and Robison 2004, p. 127) and the North Fork of 
the Red River upstream of Altus Lake (Winston et al. 1991, pp. 102-
103).

Habitat

    Little is known about the habitat requirements of the prairie chub. 
The species is known to occupy relatively large, shallow rivers of the 
Red River basin, and is typically found over clean sand or gravel 
substrates (Miller and Robinson 2004, p. 126). The peppered and prairie 
chubs are considered sister species with similar genetics and 
ecological distributions (Underwood 2003, p. 498). For this reason, we 
can use scientific information gathered on the peppered chub as a means 
to explain unknown biological and ecological attributes of the prairie 
chub. Bonner (2000, p. 16) found that the peppered chub favored 
relatively shallow depths of 18.1 to 23.5 centimeters (cm) (7.1 to 9.3 
inches (in)) and swift currents of 40 centimeters per second (cm/s) to 
62 cm/s (16 to 24 inches per second (in/s)). Peppered chubs were 
typically collected from sand substrates throughout the year; however, 
the species favored cobble substrate during the spring and gravel 
substrate during the summer (Bonner 2000, p. 17). The peppered chub was 
collected from water temperatures ranging from 0 to 34 degrees Celsius 
([deg]C) (32 to 93 degrees Fahrenheit ([deg]F)) (Bonner 2000, p. 16).

Age and Growth

    Similar to the peppered chub, the prairie chub likely has a 
relatively short lifespan, with very few individuals surviving to their 
third year (Bonner 2000, p. 44; Wilde and Durham 2008, p. 1657). Bonner 
(2000, p. 63) found that the population of peppered chubs was dominated 
by age-0 and age-1 fish, suggesting high post-spawning mortality and 
high overwinter mortality. Age-2 peppered chubs reached a maximum 
length of 77 millimeters (mm) (3 in) in the study (Bonner 2000, p. 64).

Reproduction

    Little is known about prairie chub reproduction, but based on known 
reproductive habits of other Macrhybopsis species, the prairie chub is 
likely a broadcast spawner, meaning it releases semibuoyant nonadhesive 
eggs into moving water (Platania and Altenbach 1998, p. 561). This 
reproductive strategy is considered to be an adaptation to highly 
variable stream environments (Platania and Altenbach 1998, p. 565). 
Based on drift rates and the length of time needed for egg development, 
Platania and Altenbach (1998, p. 566) suggested that peppered chub eggs 
could be transported 72 to 144 km (44 to 90 mi) before hatching. Once 
hatched, fry (recently hatched fish) could continue to be transported 
downstream another 216 km (134 mi) until they are able to swim 
(Platania and Altenbach 1998, p. 566).
    Reproductive success of species within the Macrhybopsis complex 
appears to be related to stream discharge during the spring and summer 
(Wilde and Durham 2008, p. 1658). Many studies have shown that species 
in the Macryhobopsis complex spawn during high-discharge events 
(Platania and Altenbach 1998, p. 565). However, Durham and Wilde (2006, 
pp. 1647-1649) found that young were produced throughout the summer, 
when relatively low discharge was present. In addition, Durham and 
Wilde (2006, pp. 1647-1649) found that high peak discharges were 
associated with low catch rates. Durham and Wilde (2006, p. 1651) 
concluded that there was an association between moderate peak rates and 
reproductive success of five minnows, including the peppered chub. 
Further, Bonner (2000, p. 62) found that the peppered chub spawned in 
pools; however, reproductive success was not documented. Based on these 
studies, the reproductive success of prairie chubs may be related to 
stream discharge.

Evaluation of Information for This Finding

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations at 50 CFR 424 set forth the procedures for adding a species 
to, or removing a species from, the Federal Lists of Endangered and 
Threatened Wildlife and Plants. A species may be determined to be a 
threatened or endangered 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; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    In making this 90-day finding, we evaluated whether information 
regarding threats to the prairie chub, as presented in the petition and 
in other information available in our files, is substantial scientific 
or technical information, thereby indicating that the petitioned action 
may be warranted. Our evaluation of this information is presented 
below.

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

    The petitioner asserts that impoundments, water quality, Red River 
chloride control, land use, water use, and invasive plants are threats 
to the prairie chub's habitat or range.
Impoundments
Information Provided in the Petition
    In support of the assertion that impoundments are a threat to the 
prairie chub, the petitioner suggests that stream flows within the Red 
River basin have been greatly altered by dams and dikes. These 
structures include Lake Tanglewood Dam, Altus Dam, Altus Auxiliary 
Dike, Altus East Dike, Altus Lugert Dike, Altus North Dike, Altus South 
Dike, Farmers Creek Dam, and Fish Creek Dam. The petitioner referenced 
Bonner (2000, p. 1) to describe how dams alter physical and chemical 
conditions of streams. These alterations, including changes in 
temperature and substrate, presence of backwaters, and timing and 
volume of discharge, all directly affect fish populations. A reduction 
in discharge can result in changes to channel

[[Page 20914]]

morphology and indirectly affect stream fish populations that require 
streams or rivers for all or part of their life history. For example, 
Altus Dam on the North Fork of the Red River caused changes to the fish 
community above the dam, including extirpation of the prairie chub 
(Winston et al. 1991, p. 98). In addition, Eisenhour (2004, pp. 30-31) 
states that reproduction and recruitment would be affected by 
reservoirs because the species is likely a flood-pulse spawner and 
because downstream habitat in the form of permanent flowing streams 
would be altered.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Information readily available in our files supports the 
petitioner's assertions that impoundments, such as dams and dikes, 
cause modification of prairie chub habitat. Streams and rivers of the 
Red River basin have been significantly altered by dams and small 
impoundments. A total of 660 named reservoirs and an additional 3,877 
impoundments, all 2 hectares (ha) (5 acres (ac)) or larger, have been 
constructed within the prairie chub's current known distribution. 
Twenty-eight percent of named streams (181 of 647) within the current 
prairie chub drainage have at least 1 impoundment over 2 ha (5 ac) in 
size (U.S. Geological Survey 2007, p. 1).
    Impoundments, particularly those that are regulated, cause dampened 
and less-frequent peak flows downstream of dams, and prolonged periods 
of high or no flow. Because reproduction of the prairie chub is likely 
dependent upon discharge and varying flows, any alteration of the 
natural flow regime could affect its reproductive capability. 
Regulation of flow also causes increased channelization, decreased 
complexity of stream habitats, and a loss of connectivity between the 
river and its floodplain (Dudley and Platania 2007, p. 2081). As a 
result, flow velocity is increased, which increases downstream 
transport of eggs into unsuitable reaches such as reservoirs (Dudley 
and Platania 2007, p. 2081), where the eggs drop out of suspension and 
possibly perish because of unsuitable habitat (Platania and Altenbach 
1998, p. 566). Additionally, because the connection between the river 
and its floodplain is diminished or lost, refugia for newly hatched 
fish are less available, leaving them vulnerable to potential 
predation.
    Luttrell et al. (1999, p. 986) found that extirpation of peppered 
chubs from the Arkansas River basin coincided with completion of 
reservoirs and severe drought. Their finding was supported by a life 
history model for the peppered chub, developed by Wilde and Durham 
(2008, p. 1663), that predicted that for the peppered chub population 
to be maintained, an annual discharge below the long-term average would 
have to be followed the next year by a higher-than-average discharge. 
For example, if annual discharge was less than the long-term average by 
10 percent, discharge the following year would have to exceed 11 
percent of the long-term average in order for the peppered chub 
population to recover. Because peppered and prairie chubs are thought 
to spawn only once, a quick population rebound is critical to its 
survival. Thus, impoundments throughout the prairie chub's range may 
affect the ability of the species to rebound from a population decline.
    In reference to the petitioner's claims regarding impoundments as a 
threat to the prairie chub, the information appears to be reliable. 
Information readily available in our files indicates that impoundments 
alter stream flows, which the prairie chub appears to be dependent upon 
for reproduction and recruitment. Therefore, we find that there is 
substantial information indicating that impoundments may be a threat to 
the species such that listing may be warranted.
Water Quality
Information Provided in the Petition
    The petitioner asserts that degraded water quality is a threat to 
the prairie chub. In support of this threat, the petitioner provided 
information on both Oklahoma and Texas water-quality inventories of the 
Upper Red River Basin, which demonstrate that several regions of the 
system are degraded (Oklahoma Department of Environmental Quality 2008, 
Appendix B, pp. 1-170; Texas Commission on Environmental Quality 2008, 
pp. 1-117). For example, in Texas, 11 stream segments in the Red River 
basin are on the Environmental Protection Agency's Clean Water Act 
303(d) list of degraded waters. These segments make up close to 1,448 
km (900 mi) of stream. Additionally, malathion (a chemical toxic to 
fishes) is used to eradicate boll weevils (Anthonomus grandis) from 
cotton crops in the region (Grefenstette and El-Lissy 2003, p. 131). 
Furthermore, the petitioner references Jester et al. (1992, p. 14) to 
state that the speckled chub (incorrectly referenced as prairie chub in 
the petition) is intolerant of changes to habitat and moderately 
intolerant to changes in water quality.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    With regard to degraded water quality being a threat to the prairie 
chub, the information provided by the petitioner appears to be 
reliable. Information in our files supports the petitioner's assertion 
that water quality in many streams of the upper Red River basin is 
degraded to some degree and that prairie chubs may be susceptible to 
this degradation. Of the 14 streams known to recently support prairie 
chubs, the Environmental Protection Agency considers 10 of those to be 
impaired due to one or more of the following parameters: Fecal 
coliform, total dissolved solids, Escherichia coli, Enterococcus, 
turbidity, chlorides, selenium, sulfates, lead, 
dichlorodiphenyltrichloroethane (DDT), Toxaphene, and fish 
bioassessments (EPA 2008, p. 1). These elements are detrimental to 
water quality and affect fishes by limiting their potential 
distribution, lowering dissolved oxygen, and accumulating in fish 
tissues. Additionally, a study by Adornato and Martin (1995, p. 18) 
concluded that fish within their project area, including two streams 
occupied by prairie chubs, were highly contaminated with organochlorine 
pesticides, including dieldrin, DDT metabolites, and Toxaphene, all of 
which are known to be toxic to all fishes. Selenium, also toxic to 
fishes, was found to be elevated, which the authors attributed to crop 
irrigation (Adornato and Martin 1995, p. 18). Because various chemical 
toxins have been found in the same streams of the prairie chub, and the 
toxins are known to cause mortalities in all fishes, degraded water 
quality may be a threat to the species. Therefore, we find that the 
petition and information in our files provides substantial information 
indicating that listing the prairie chub may be warranted due to 
degraded water quality.
Red River Chloride Control
Information Provided in the Petition
    The petitioner asserts that the U.S. Army Corps of Engineers' (ACE) 
Red River Chloride Control Project is a threat to the prairie chub. The 
ACE is authorized to identify and implement measures to reduce 
naturally occurring brine emissions into several Red River basins in 
Texas and Oklahoma. The project's primary purpose is to minimize 
chloride inputs into the Red River. The petitioner references Matthews 
et al. (2005, p. 304) and states that completion of the program to 
control chlorides in the Upper Red

[[Page 20915]]

River Basin will threaten the natural salinity gradient upon which many 
flora and fauna depend. Additionally, if chloride levels in the upper 
Red River basin were lowered to the point that allowed for additional 
irrigation, water withdrawals would increase and hydrologic estimates 
suggest that ``no-flow'' days in the upper basin might be tripled 
annually. Taylor et al. (1993, p. 22) is also referenced in the 
petition, suggesting that the chloride control program could have a 
substantial effect on the fish community structure.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    In reference to the petitioner's claims that the Red River Chloride 
Control Project is a threat to the prairie chub, the information 
appears to be reliable. Information in our files confirms the 
petitioner's assertion that the project could alter existing stream 
flows, thus negatively affecting the prairie chub's ability to 
successfully reproduce. According to projections supplied by the ACE, 
the project would result in average annual streamflow reductions 
ranging from a 4.5 percent reduction in the Elm Fork of the Red River 
to a 52 percent reduction in the South Fork of the Wichita River 
(Service 1996, p. iii). The project, in combination with irrigation 
withdrawals anticipated following project implementation, is expected 
to increase the number of average annual no-flow days from a low of 3 
days at the Benjamin, Texas, gage to a high of 67 days at the Vernon, 
Texas, gage (Service 1996, p. iii). This decrease in flows could 
eliminate existing resources, such as food and habitat, and could 
result in less dilution of environmental contaminants that are known to 
exist in the system (Adornato and Martin 1995, p. 18; EPA 2008, p. 1). 
By limiting resources and potentially increasing the concentrations of 
contaminants, the Red River Chloride Control Project could possibly 
have negative impacts on the prairie chub.
    Also, an increase in no-flow days would affect the prairie chub's 
ability to spawn. Because discharge is necessary for successful 
reproduction (Durham and Wilde 2006, p. 1647), any increase in the 
number of no-flow days would decrease the number of days prairie chubs 
have available to spawn. Because prairie chub eggs disperse downstream 
after spawning (Platania and Altenbach 1998, p. 566), more frequent no-
flow days in combination with lower overall flows could minimize 
dispersal and potentially cause an overall reduction in populations.
    After reviewing information provided by the petitioner and readily 
available in our files, we find that substantial information exists 
indicating that the Red River Chloride Control Project, including 
impacts of reduced stream flow and degraded water quality may be a 
threat to the prairie chub, such that listing may be warranted.
Land Use
Information Provided in the Petition
    The petitioner asserts that land use changes are a threat to the 
prairie chub. In support of this claim, the petitioner references 
Steuter et al. (2003, p. 53) to describe how southern short- and mid-
grass river systems, including Red River basin streams, have been 
altered by land use changes like oil and gas production and 
agriculture.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Regarding the petitioner's claim that land use changes are a threat 
to the prairie chub, the information appears to be reliable. 
Agriculture is the principal land use throughout the Red River basin. 
Floodplain soils are generally well suited for alfalfa, wheat, corn, 
cotton, peanuts, grain sorgum, and other small grains. Consequently, 
native floodplain vegetation has been cleared or fragmented into small, 
isolated patches and replaced with pasture, hay, vegetables, and small 
grains. Contaminants widely known to originate from agricultural 
operations also appear to negatively impact fish and wildlife in the 
upper Red River basin and are described above under Water Quality. 
Besides agriculture-related contaminants, the information provided by 
the petitioner and readily available in our files does not indicate 
that any other agriculture-related activities are impacting the prairie 
chub in a way that may pose a threat to the species.
    In reference to the petitioner's claims that oil and gas production 
has altered Red River basin streams, information available in our files 
indicates that oil and gas production has eliminated or fragmented 
native plant communities throughout the Red River basin (Service 1996, 
p. 5); however, the petitioner provided no information indicating how 
this potential impact may be acting on the species. Therefore, the 
petitioner has not provided substantial information indicating that 
land use changes from oil and gas production may be a threat to the 
prairie chub.
    In summary, we find the petition, along with information readily 
available in our files, presents substantial information indicating 
that agricultural-related contaminants, which are described above under 
Water Quality, may pose a threat to the prairie chub such that listing 
may be warranted. However, neither the petition or information in our 
files, present substantial information to suggest that oil and gas 
production impacts the prairie chub at a level where listing may be 
warranted.
Agricultural Water Use
Information Provided in the Petition
    The petitioner asserts that agricultural water use is a threat to 
the prairie chub. The petitioner provided information from Steuter et 
al. (2003, p. 53) stating that river flows have been greatly altered by 
dams and excessive groundwater withdrawals for irrigation. In addition, 
the petitioner cited Eisenhour (2004, pp. 30-31) to describe the 
potential disruptive impacts from water modification (reservoir 
construction, channelization, and groundwater withdrawals) on 
reproduction and recruitment of the prairie chub.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    In reference to the petitioner's claim that water use, primarily 
irrigation, is a threat to the prairie chub, the information appears to 
be reliable. Ground and surface water withdrawals for irrigation can 
have significant negative impacts on the prairie chub. One of the major 
factors contributing to the decline of the Federally listed Arkansas 
River shiner (Notropis girardi) is water depletion due to irrigation 
for agriculture (Service 1998, pp. 64773, 64779). Irrigation, in 
combination with water depletions from the Red River Chloride Control 
Project, could significantly reduce flows in the upper Red River basin 
(Service 1996, p. iii). The detrimental effects of decreased water 
flows on the prairie chub are described above under Impoundments and 
Red River Chloride Control Project. Based on the effects of reduced 
flows, the information provided by the petitioner and readily available 
in our files indicates that agricultural water use and subsequent 
stream flow reduction may be a threat to the prairie chub, such that 
listing may be warranted.
Invasive Plants
Information Provided in the Petition
    The petitioner asserts that invasive plants are a threat to the 
prairie chub.

[[Page 20916]]

In support of this threat, the petitioner states that saltcedar 
(Tamarix spp.) and Russian olive (Elaeagnus angustifolia) are prolific 
along the Red River and its tributaries (DeLoach 2009, p. 1). Further, 
the petitioner claims that both plants can be detrimental to native 
plains fishes by decreasing stream flows.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Regarding the petitioner's claims that invasive plants may be a 
threat to the prairie chub, the information appears to be reliable. The 
banks of the Red River once sustained growth of tall willows (Salix 
spp.) and cottonwoods (Populus deltoides), but these trees have been 
supplanted by saltcedar and Russian olive (Texas Parks and Wildlife 
Department 2005, p. 151). Early studies of water use by saltcedar have 
led many to assume that removal of saltcedar would result in water 
savings, primarily as increased flows in rivers (U.S. Geological Survey 
2009, p. 43). Some research has shown that removal of saltcedar from 
spring ecosystems may be beneficial to fish species by increasing 
groundwater inputs and available habitat (DeLoach 2009, p. 1). However, 
saltcedar and Russian olive removal projects on larger streams and 
rivers, which were intended to increase stream flows, have provided 
mixed results (U.S. Geological Survey 2009, pp. 43-44). In a few cases, 
clearing saltcedar resulted in temporary increases in stream flow (U.S. 
Geological Survey 2009, pp. 43-44). But, most studies found no 
significant long-term changes in stream flow (U.S. Geological Survey 
2009, pp. 43-44). A U.S. Geological Survey (2009, p. ix) report 
suggests that additional research is needed at a scale large enough to 
detect changes to the water budget, and that all variables associated 
with the water budget should be examined. Based on information provided 
by the petitioner and readily available in our files, it appears that 
more research is needed to determine the actual impacts of saltcedar 
and Russian olive on stream flows in the upper Red River and to 
determine the extent that this impact may have on the prairie chub. At 
this time, it is unclear whether invasive plants may be a threat to the 
prairie chub. Therefore, we will analyze this issue further in the 12-
month finding.
    Additionally, saltcedar and Russian olive encroachment has been 
shown to alter stream geomorphology by narrowing and deepening channels 
through dense accumulation along the banks (Hultine et al. 2009, p. 
469). This alteration to stream morphology limits the stream's 
connectivity with the floodplain, which is needed for native plant 
establishment (Hultine et al. 2009, p. 469) and refugia habitat for 
fishes. However, the petitioner provided no information to indicate 
that saltcedar and Russian olive within the current range of the 
prairie chub are at high enough densities, nor will be in the future, 
to alter stream morphology and affect the prairie chub's habitat.
    In conclusion, information provided by the petition, and readily 
available in our files, is unclear about whether invasive plants, 
particularly saltcedar or Russian olive, may be a threat to the prairie 
chub because of stream flow alterations. Therefore, we will investigate 
this issue further in the 12-month finding.
    In summary of the Factor A analysis, we find that the petition, 
along with information available in our files, has presented 
substantial information indicating that the prairie chub may warrant 
listing due to the present or threatened destruction, modification, or 
curtailment of its habitat or range, primarily due to impoundments 
altering stream flows, degraded water quality, the Red River Chloride 
Control Project, and irrigation.

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

Information Provided in the Petition
    The petition does not present any information concerning impacts 
from overutilization for commercial, recreational, scientific, or 
educational purposes to the prairie chub.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    We have no information available in our files to indicate that any 
impact from overutilization is occurring to the prairie chub. 
Therefore, we find that the petition, along with information readily 
available in our files, has not presented substantial information that 
the prairie chub may warrant listing due to overutilization for 
commercial, recreational, scientific, or educational purposes.

C. Disease or Predation

Information Provided in the Petition
    The petitioner asserts that nonnative species, such as bullfrogs 
(Rana catesbeiana), may be a threat to the prairie chub. However, the 
petitioner does not provide any information indicating how nonnative 
species may be impacting the prairie chub.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    We have no information available in our files to indicate that 
nonnative species, disease, or predation are impacting the prairie 
chub. Therefore, we find that the petition, along with information 
readily available in our files, has not presented substantial 
information that the prairie chub may warrant listing due to disease or 
predation.

D. The Inadequacy of Existing Regulatory Mechanisms

Information Provided in the Petition
    The petitioner asserts that the inadequacy of existing regulatory 
mechanisms is a threat to the prairie chub. In support of this claim, 
the petitioner states that the prairie chub receives no Federal or 
State protection, even though the prairie chub is listed as a Tier-I 
priority species in Oklahoma under the State's Comprehensive Wildlife 
Conservation Strategy, and the Texas Comprehensive Conservation 
Strategy lists the prairie chub as a medium-priority Species of 
Concern. Also, the petitioner states that the Oklahoma Comprehensive 
Conservation Strategy does not identify specific conservation actions 
that will benefit the species.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    In reference to the petitioner's claim that the inadequacy of 
existing regulatory mechanisms is a threat to the species, the 
information appears reliable. However, in 2007 the State of Texas 
developed legislation that authorized a program that could be 
beneficial to the prairie chub by requiring an instream flow. An 
instream flow requirement, as defined by the National Academy of 
Sciences (NAS), is the amount of water flowing through a natural stream 
course that is needed to sustain, rehabilitate, or restore the 
ecological functions of a stream in terms of hydrology, biology, 
geomorphology, connectivity, and water quality at a particular level 
(NAS 2005, p. 139). Although this could be beneficial to the prairie 
chub, we have no information in our files showing that any parts of the 
program have been implemented for the Red River. No such instream flow 
legislation exists in the State of Oklahoma. Without protection of 
existing flows, the prairie chub's habitat could be significantly 
altered. The alteration of natural flows could disrupt the species' 
ability to successfully

[[Page 20917]]

spawn and disperse throughout the upper Red River basin. For more 
details on how reduced flows impact the prairie chub, see discussion in 
the Impoundments and Red River Chloride Control Project sections.
    Also, the EPA (2008, p. 1) established Total Maximum Daily Loads 
for many of the streams occupied by the prairie chub in order to reduce 
water degradation. However, we have no information in our files to 
suggest that measures to meet the established Total Maximum Daily Loads 
standards have been implemented.
    In summary, we find that the petition, along with information 
readily available in our files, presents substantial information 
indicating that prairie chub may warrant listing due to the inadequacy 
of existing regulatory mechanisms, primarily due to inadequate 
protections of water quality and stream flow.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

Invasive Aquatic Species
Information Provided in the Petition
    The petitioner asserts that nonnative aquatic species are threats 
to the prairie chub. In support of this claim, the petitioner 
references Gido et al. (2004, p. 128) to assert that invasive nonnative 
species may cause fish population declines in the southern Great Plains 
river systems. Additionally, the petitioner states that nonnative 
species that have invaded the Red River basin include common carp 
(Cyprinus carpio), threadfin shad (Dorosoma petensense), and inland 
silverside (Menidia beryllina). However, neither the petitioner, nor 
the references provided, identifies how nonnative species impact the 
prairie chub.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Information in our files supports the assertion that nonnative fish 
species may cause native fish population declines in the southern Great 
Plains river systems, but there is no evidence that nonnative species 
are impacting the prairie chub. Gido (2004, p. 129) found that Great 
Plains streams appear to be gaining introduced species at the rate of 
0.5 species every 18 years. One example is the introduction and 
establishment of the Red River shiner (Notropis bairdi), a species 
endemic to the Red River drainage, into the Cimarron River in Oklahoma 
and Kansas, which has had a detrimental effect on the Arkansas River 
shiner by competing for limited resources (Cross et al. 1983, pp. 93-
98; Felley and Cothran 1981, p. 564). The Red River shiner was first 
recorded from the Cimarron River in 1976 (Marshall 1978, p. 109). It 
has since colonized the Cimarron River and may be a dominant component 
of the fish community (Cross et al. 1983, pp. 93-98; Felley and Cothran 
1981, p. 564; Service unpublished data 2007-2010). However, we do not 
consider the Red River shiner to be a threat to the prairie chub. 
Because the Red River shiner is endemic to the Red River basin, it has 
adapted and evolved with the prairie chub. Therefore, it is not 
considered an invasive species, and there is no evidence indicating 
that competition with the Red River shiner has any impacts on the 
prairie chub.
    In addition, the petitioners have provided no information 
indicating how the three invasive species mentioned in the petition 
(common carp, threadfin shad, and inland silverside) may be acting on 
the prairie chub, or whether an impact from these species may actually 
be occurring within the chub's range. Although the adverse effects from 
invasive aquatic species are evident for other native fish species, 
neither the petition nor information available in our files presented 
substantial information indicating that nonnative species may be a 
threat to the prairie chub, such that listing may be warranted.
Climate Change
Information Provided in the Petition
    The petitioner asserts that climate change is a threat to the 
prairie chub, and further notes that climate change poses a fundamental 
challenge for all species' survival in the coming years and decades. 
The petitioner provided information suggesting that climate change is 
already causing a rise in temperatures across the United States and is 
increasing extreme weather events such as droughts and increased 
rainfall (NSC 2003, pp. 43-44; USCCSP 2008, pp. 35-36). The petitioner 
referenced the Intergovernmental Panel on Climate Change (IPCC) (2007, 
p. 30) and stated that 11 of the 12 years from 1995 through 2006 ranked 
among the 11 warmest years on instrumental record. The petitioner also 
cites an IPCC 2007 report (p. 48) to discuss how resilience of many 
ecosystems is likely to be exceeded, and that 20 to 30 percent of plant 
and animal species assessed are likely to be at increased risk of 
extinction.
    In further support of climate change being a threat to the prairie 
chub, the petitioner provided information on climate change within the 
Great Plains, where more extreme and frequent weather events are 
expected, including droughts, heavy rainfall, and heat waves (Karl et 
al. 2009, pp. 123-128). The petitioner asserts that some species may 
not be able to adapt to projected changes in temperature and climate 
change when combined with human-induced stresses (Karl et al. 2009, pp. 
123-128). In referencing Matthews and Marsh-Matthews (2003, p. 1232), 
the petitioner asserts that the additional stress of drought will only 
be exacerbated if climate change is already increasing the severity and 
duration of droughts in the southern Great Plains. The petitioner cited 
Matthews and Marsh-Matthews (2003, p. 1232) in stating that projected 
climate change may result in massive changes in fish biodiversity and 
widespread extirpation of fish species in many regions.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    In reference to the petitioner's claim that climate change is a 
threat to the prairie chub, the information appears reliable; however, 
we are lacking information that links reliable impacts from climate 
change to effects on prairie chub populations. According to the IPCC 
(2007, p. 1), ``Warming of the climate system is unequivocal, as is now 
evident from observations of increases in global average air and ocean 
temperatures, widespread melting of snow and ice, and rising global 
average sea level.'' Average Northern Hemisphere temperatures during 
the second half of the 20th century were very likely higher than during 
any other 50-year period in the last 500 years and likely the highest 
in at least the past 1,300 years (IPCC 2007, p. 1). It is very likely 
that over the past 50 years, cold days, cold nights, and frosts have 
become less frequent over most land areas, and hot days and hot nights 
have become more frequent (IPCC 2007, p. 1). Data suggest that heat 
waves are occurring more often over most land areas, and the frequency 
of heavy precipitation events has increased over most areas (IPCC 2007, 
p. 1).
    Regional analysis for the Great Plains from North Dakota to Texas 
predicts that hot extremes, heat waves, and heavy precipitation events 
will increase in frequency (IPCC 2007, p. 8). Milly et al. (2005, p. 
349) projected a 10 to 30 percent decrease in runoff in mid-latitude 
western North America by the year 2050, based on an ensemble of 12 
climate models. However, predictions for smaller subregions, such as 
Oklahoma and Texas, are not presented in the petition or readily 
available in our files. In addition, the petitioner did

[[Page 20918]]

not provide information indicating how climate change might potentially 
impact the prairie chub. The prairie chub has persisted for millennia 
with periods of extreme weather events, such as droughts and floods. If 
climate change causes more extreme weather events, there is no 
information to indicate that such events will have a negative impact on 
the prairie chub. At this time, we lack sufficient certainty to know 
specifically how climate change will affect the species. We are not 
aware of any data at an appropriate scale to evaluate habitat or 
population trends for the prairie chub within its range, make 
predictions about future trends, or determine whether the species will 
actually be impacted. Therefore, based on information presented by the 
petitioner and readily available in our files, we do not consider 
climate change to be a threat to the species; however, we intend to 
investigate this factor more thoroughly in our status review of the 
species.
    In summary, we find that the petition, along with information 
readily available in our files, has not presented substantial 
information that the prairie chub may warrant listing due to other 
natural or manmade factors.

Finding

    On the basis of our determination under section 4(b)(3)(A) of the 
Act, we have determined that the petition presents substantial 
scientific or commercial information indicating that listing the 
prairie chub throughout its entire range may be warranted. This finding 
is based on information provided under factors A and D about the 
potential threats from altered stream flows and degraded water quality, 
and inadequacy of existing regulatory mechanisms to protect prairie 
chubs from altered stream flows or degraded water quality. We determine 
that the information provided under factors B, C, and E is not 
substantial. In considering what factors might constitute threats, we 
must look beyond the mere exposure of the species to the factor to 
determine whether the species responds to the factor in a way that 
causes actual impacts to the species. If there is exposure to a factor, 
but no response, or only a positive response, that factor is not a 
threat. If there is exposure and the species responds negatively, the 
factor may be a threat and we then attempt to determine how significant 
a threat it is. If the threat is significant, it may drive or 
contribute to the risk of extinction of the species such that the 
species may warrant listing as threatened or endangered as those terms 
are defined by the Act. This does not necessarily require empirical 
proof of a threat. The combination of exposure and some corroborating 
evidence of how the species is likely impacted could suffice. The mere 
identification of factors that could impact a species negatively may 
not be sufficient to compel a finding that listing may be warranted. 
The information must contain evidence sufficient to suggest that these 
factors may be operative threats that act on the species to the point 
that the species may meet the definition of threatened or endangered 
under the Act.
    Because we have found that the petition presents substantial 
information indicating that listing the prairie chub may be warranted, 
we are initiating a status review to determine whether listing the 
prairie chub as threatened or endangered under the Act is warranted.
    The ``substantial information'' standard for a 90-day finding 
differs from the Act's ``best scientific and commercial data'' standard 
that applies to a status review to determine whether a petitioned 
action is warranted. A 90-day finding does not constitute a status 
review under the Act. In a 12-month finding, we will determine whether 
a petitioned action is warranted after we have completed a thorough 
status review of the species, which is conducted following a 
substantial 90-day finding. Because the Act's standards for 90-day and 
12-month findings are different, as described above, a substantial 90-
day finding does not mean that the 12-month finding will result in a 
warranted finding.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Oklahoma 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Author

    The primary author of this notice is the staff of the Oklahoma 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authority

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

    Dated: April 4, 2011.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-9089 Filed 4-13-11; 8:45 am]
BILLING CODE 4310-55-P
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