Endangered and Threatened Wildlife and Plants; Reclassification of the Oregon Chub From Endangered to Threatened, 21179-21189 [2010-9375]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 75, Number 78 (Friday, April 23, 2010)]
[Rules and Regulations]
[Pages 21179-21189]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-9375]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2009-0005; 92220-1113-0000-C6]
RIN 1018-AW42


Endangered and Threatened Wildlife and Plants; Reclassification 
of the Oregon Chub From Endangered to Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are 
reclassifying the federally endangered Oregon chub (Oregonichthys 
crameri) to threatened status under the authority of the Endangered 
Species Act of 1973, as amended (Act). This decision is based on a 
thorough review of the best available scientific and commercial data, 
which indicate that the species' status has improved to the point that 
the Oregon chub is not currently in danger of extinction throughout all 
or a significant portion of its range.

DATES: This final rule is effective on May 24, 2010.

ADDRESSES: Comments and materials received, as well as supporting 
documentation used in the preparation of this final rule, are available 
for inspection, by appointment, during normal business hours, at the 
U.S. Fish and Wildlife Service, Oregon Fish and Wildlife Office, 2600 
SE 98th Avenue, Suite 100, Portland, OR 97266; (telephone 503/231-
6179).

FOR FURTHER INFORMATION CONTACT: State Supervisor, U.S. Fish and 
Wildlife Service, Oregon Fish and Wildlife Office (see ADDRESSES). 
Persons who use a telecommunications device for the deaf (TDD) may call 
the Federal Information Relay Service (FIRS) at 800/877-8339, 24 hours 
a day, 7 days a week.

SUPPLEMENTARY INFORMATION:

Background

    The purposes of the Act (16 U.S.C. 1531 et seq.) are to provide a 
means whereby the ecosystems upon which endangered and threatened 
species depend may be conserved and to provide a program for the 
conservation of those species. A species can be listed as endangered or 
threatened because of any of the following factors: (1) The present or 
threatened destruction, modification, or curtailment of its habitat or 
range; (2) overutilization for commercial, recreational, scientific, or 
educational purposes; (3) disease or predation; (4) the inadequacy of 
existing regulatory mechanisms; or (5) other natural or manmade factors 
affecting its continued existence. When we determine that protection of 
a species under the Act is no longer warranted, we take steps to remove 
(delist) the species from the Federal list. If a species is listed as 
endangered, we may reclassify it to threatened status as an 
intermediate step before delisting; however, reclassification to 
threatened status is not required in order to delist.
    Section 3 of the Act defines terms that are relevant to this final 
rule. An endangered species is any species that is in danger of 
extinction throughout all or a significant portion of its range. A 
threatened species is any species that is likely to become an 
endangered species within the foreseeable future throughout all or a 
significant portion of its range. A species includes any subspecies of 
fish or wildlife or plants, and any distinct population segment of any 
species of vertebrate fish or wildlife that interbreeds when mature.

Previous Federal Actions

    In our December 30, 1982, Review of Vertebrate Wildlife for Listing 
as Endangered or Threatened Species, we listed the Oregon chub as a 
Category 2 candidate species (47 FR 58454). Category 2 candidates, a 
designation no longer used by the Service, were species for which 
information contained in Service files indicated that proposing to list 
was possibly appropriate but additional data were needed to support a 
listing proposal. The Oregon chub maintained its Category 2 status in 
both the September 18, 1985 (50 FR 37958) and January 6, 1989 (54 FR 
554) Notices of Review.
    On April 10, 1990, the Service received a petition to list the 
Oregon chub as an endangered species and to designate critical habitat. 
The petition and supporting documentation were submitted by Dr. Douglas 
F. Markle and Mr. Todd N. Pearsons, both affiliated with Oregon State 
University. The

[[Page 21180]]

petitioners submitted taxonomic, biological, distributional, and 
historical information and cited numerous scientific articles in 
support of the petition. The petition and accompanying data described 
the Oregon chub as endangered because it had experienced a 98 percent 
range reduction and remaining populations faced significant threats. On 
November 1, 1990, the Service published a 90-day finding indicating 
that the petitioners had presented substantial information indicating 
that the requested action may be warranted and initiated a status 
review (55 FR 46080).
    On November 19, 1991, the Service published a 12-month finding on 
the petition concurrent with a proposal to list the species as 
endangered (56 FR 58348). On October 18, 1993, we published a final 
rule listing the Oregon chub as endangered (58 FR 53800). A 5-year 
review of the Oregon chub's status was completed in February 2008 (U.S. 
Fish and Wildlife Service 2008a, pp. 1-34); this review concluded that 
the Oregon chub's status had substantially improved since listing, and 
that the Oregon chub no longer met the definition of an endangered 
species, but did meet the definition of a threatened species, under the 
Act. The review, therefore, recommended that we downlist the Oregon 
chub from endangered to threatened.
    On March 10, 2009, the Service published a proposed rule (74 FR 
10412) to designate critical habitat for the Oregon chub. The public 
comment period on the proposal was open for 60 days, from March 10, 
2009, to May 11, 2009. We subsequently reopened the public comment 
period on the critical habitat proposal on September 22, 2009, for an 
additional 30 days, ending October 22, 2009 (74 FR 48211). During the 
reopened public comment period, we held a public hearing in Corvallis, 
Oregon. We published a final rule designating critical habitat on March 
10, 2010 (75 FR 11010).
    On May 15, 2009, we published a proposed rule to reclassify the 
Oregon chub from endangered to threatened (74 FR 22870). We contacted 
interested parties (including elected officials, Federal and State 
agencies, local governments, scientific organizations, interest groups, 
and private landowners) through a press release and related fact 
sheets, faxes, mailed announcements, telephone calls, and e-mails. In 
addition, we notified the public and invited comments through news 
releases to media outlets throughout the region, including major 
newspapers (The Oregonian [Portland, OR], The Statesman-Journal [Salem, 
OR], and The Register-Guard [Eugene, OR]), and television and radio 
news stations. The public comment period on the proposal was open for 
60 days, from May 15, 2009, to July 14, 2009.
    On May 19, 2009, the Service published a notice in the Federal 
Register announcing the Oregon Department of Fish and Wildlife's (ODFW) 
application for an enhancement of survival permit under section 
10(a)(1)(A) of the Act (74 FR 23431). The permit application included a 
proposed Programmatic Safe Harbor Agreement between ODFW and the 
Service (Oregon Department of Fish and Wildlife and U.S. Fish and 
Wildlife Service 2009, pp. 1-30). We issued the permit on August 31, 
2009. The term of the permit and agreement is 30 years. The permit 
authorizes ODFW to extend incidental take coverage with assurances to 
eligible landowners who are willing to carry out habitat management 
measures that would benefit the Oregon chub by enrolling them under the 
agreement as Cooperators through issuance of Certificates of Inclusion. 
The geographic scope of the agreement includes all non-Federal 
properties throughout the estimated historical distribution of the 
species in the Willamette Valley (i.e., between the cities of Oregon 
City and Oakridge, Oregon).

Species Information

    The Oregon chub is a small minnow (Family Cyprinidae) endemic to 
the Willamette River Basin in western Oregon (Markle et al. 1991, p. 
288). The Oregon chub has an olive-colored back grading to silver on 
the sides and white on the belly (Markle et al. 1991, p. 286). Oregon 
chub are found in slack water, off-channel habitats such as beaver 
ponds, oxbows, side channels, backwater sloughs, low-gradient 
tributaries, and flooded marshes. These habitats usually have little or 
no water flow, silty and organic substrate, and abundant aquatic 
vegetation for hiding and spawning cover (Pearsons 1989, p. 12; 
Scheerer and McDonald 2000, p. 9). Summer temperatures in shallow ponds 
inhabited by Oregon chub generally exceed 16 degrees Celsius (C) (61 
degrees Fahrenheit (F)) (Scheerer et al. 1998, p. 26). In the winter 
months, Oregon chub are found buried in detritus or concealed in 
aquatic vegetation (Pearsons 1989, p. 16).
    Oregon chub reach maturity at about 2 years of age (Scheerer and 
McDonald 2003, p. 78) and in wild populations can live up to 9 years. 
Most individuals over 5 years old are females (Scheerer and McDonald 
2003, p. 68). Oregon chub spawn in warm (16 to 21 degrees C (61 to 70 
degrees F)) shallow water from June through August (Scheerer and 
McDonald 2000, p. 10). The diet of Oregon chub collected in a May 
sample consisted primarily of copepods, cladocerans, and chironomid 
larvae (Markle et al. 1991, p. 288).
    In the early 1990s, Oregon chub populations were found 
predominantly in the Middle Fork Willamette River (Middle Fork), with a 
few, small populations found in the Mid-Willamette River, Santiam 
River, and Coast Fork Willamette River (Coast Fork). The species is now 
well distributed throughout the Willamette Basin (in Polk, Marion, 
Linn, Lane, and Benton Counties, Oregon), with populations in the 
Santiam River (9 sites), Mid-Willamette River (6 sites), McKenzie River 
(4 sites), Middle Fork (16 sites), and Coast Fork (3 sites) (Bangs et 
al. 2008, p. 7). There are currently 19 populations that contain more 
than 500 adults each; 16 of these have a stable or increasing trend 
(Bangs et al. 2008, pp. 7-10).

Review of the Recovery Plan

    The Service published a final recovery plan for the Oregon chub in 
1998 (U.S. Fish and Wildlife Service 1998). Recovery plans are intended 
to guide actions to recover listed species and to provide measurable 
objectives against which to measure progress towards recovery; however, 
precise attainment of the recovery criteria is not a prerequisite for 
downlisting or delisting. The Oregon chub recovery plan established the 
following criteria for downlisting the species from endangered to 
threatened:
    (1) Establish and manage 10 populations of at least 500 adults 
each;
    (2) All of these populations must exhibit a stable or increasing 
trend for 5 years; and
    (3) At least three populations must be located in each of the three 
sub-basins of the Willamette River identified in the plan (Mainstem 
Willamette River, Middle Fork, and Santiam River).
    The recovery plan established the following criteria for delisting 
(i.e., removing the species from the List of Endangered and Threatened 
Wildlife):
    (1) Establish and manage 20 populations of at least 500 adults 
each;
    (2) All of these populations must exhibit a stable or increasing 
trend for 7 years;
    (3) At least four populations must be located in each of the three 
sub-basins (Mainstem Willamette River, Middle Fork, and Santiam River); 
and
    (4) Management of these populations must be guaranteed in 
perpetuity.

[[Page 21181]]

    Recovery actions specified in the recovery plan to achieve the 
downlisting and delisting goals included managing existing sites, 
establishment of new populations, research into the ecology of the 
species, and public education and outreach to foster greater 
understanding of the Oregon chub and its place in the natural 
environment of the Willamette Basin (U.S. Fish and Wildlife Service 
1998, pp. 28-44).

Recovery Plan Implementation

    When we listed the Oregon chub as endangered in 1993, it was known 
to occur at only nine locations within a 30-kilometer (18.6-mile) reach 
of the Willamette River, representing just 2 percent of its historical 
range (Markle et al. 1991, p. 288). Since 1992, the Service, ODFW, U.S. 
Army Corps of Engineers (Corps), U.S. Forest Service, Oregon Parks and 
Recreation Department, and Oregon Department of Transportation have 
funded ODFW staff to conduct surveys for Oregon chub throughout the 
Willamette Valley. ODFW has surveyed 650 off-channel habitats and small 
tributaries in the Willamette River Basin (Scheerer 2007, p. 92), 
greatly increasing our knowledge of the current and potential habitat 
available to the Oregon chub. Other research projects have resulted in 
new information on the species' habitat use, timing of spawning, and 
age and growth patterns (U.S. Fish and Wildlife Service 2008a, pp. 13-
15).
    The status of the Oregon chub has improved dramatically since it 
was listed as endangered. The improvement is due largely to the 
implementation of actions identified in the Oregon chub recovery plan. 
This includes the discovery of many new populations as a result of 
ODFW's surveys of the basin, and the establishment of additional 
populations via successful reintroductions within the species' 
historical range (Scheerer 2007, p. 97). To date, Oregon chub 
populations have been introduced at 16 sites (9 in the Mainstem 
Willamette sub-basin, 4 in the Middle Fork sub-basin, and 3 in the 
Santiam sub-basin) (Bangs et al. 2008, p. 7). Introduced populations 
have been established in suitable habitats with low connectivity to 
other aquatic habitats to reduce the risk of invasion by nonnative 
fishes (see Summary of Factors Affecting the Species--Factor C below 
for more information) (Scheerer 2007, p. 98). At present, 7 of these 
populations persist and exhibit stable or increasing trends; 2 
populations were reintroduced too recently to evaluate success (i.e., 
the populations introduced in 2008 at St. Paul Ponds and Sprick Pond); 
and 5 introduced populations have been extirpated or are not likely to 
remain viable. Reasons for reintroduction failures include pond 
desiccation, low dissolved oxygen, unauthorized introductions of 
nonnative predatory fishes, and high mortality of introduced fish 
(Scheerer et al. 2007, p. 2; Scheerer 2008a, p. 6; Scheerer 2009a, p. 
1).
    Currently, there are 38 Oregon chub populations, of which 19 have 
more than 500 adults (Bangs et al. 2008, p. 7). Sixteen years have 
passed since listing, and the species is now relatively abundant and 
well distributed throughout much of its presumed historical range. The 
risk of extinction has been substantially reduced as threats have been 
managed, and as new populations have been discovered or re-established. 
The Oregon chub has exceeded or met nearly all of the criteria for 
downlisting to threatened described in the recovery plan. A review of 
the species' current status relative to the downlisting criteria from 
the Recovery Plan follows.
    Downlisting Criterion 1: Establish and manage 10 populations of at 
least 500 adults each. This criterion has been exceeded. There are 19 
populations with more than 500 adult Oregon chub (see Table 1 below).
    Downlisting Criterion 2: All 10 populations referenced in 
Downlisting Criterion 1 must exhibit a stable or increasing trend for 5 
years. This criterion has been exceeded; there are 16 populations with 
at least 500 adults that are stable or increasing (see Table 1 below). 
Scheerer et al. (2007, p. 4) defined abundance trends as increasing, 
declining, stable, or not declining using linear regression of 
abundance estimates over time for each population with more than 500 
adult fish over the last 5 years. When the slope of this regression was 
negative and significantly different from zero (P>0.10), the population 
was categorized as declining. When the slope was positive and 
significantly different from zero (P<0.10), the population was 
categorized as increasing. When the slope was not significantly 
different from zero (P>0.10), Scheerer et al. (2007, p. 4) calculated 
the coefficient of variation of the abundance estimates to discriminate 
between populations that were stable (i.e., low variation in population 
abundance estimates) and those that were unstable but not declining 
(i.e., high variation in population abundance estimates). When the 
coefficient of variation was less than 1.0, the population was defined 
as stable; otherwise, the population was considered unstable but not 
declining (see Table 1 below).
    Downlisting Criterion 3: At least three populations (which meet 
downlisting criteria 1 and 2 above) must be located in each of the 
three sub-basins of the Willamette River (Mainstem Willamette River, 
Middle Fork Willamette, and Santiam River). This criterion has been 
exceeded in two sub-basins, and is nearly accomplished in the third. In 
the Mainstem Willamette River sub-basin, there are 6 populations with 
500 or more Oregon chub with stable or increasing trends; in the Middle 
Fork Willamette sub-basin, there are 8 populations with 500 or more 
Oregon chub with stable or increasing trends; and in the Santiam River 
sub-basin, there are 3 populations with 500 or more Oregon chub, but 
only 2 with stable or increasing trends over the last 5 years (see 
Table 1 below). Five-year trends were calculated for abundant 
populations (>500 individuals for the last 5 years) only. Table 1 shows 
the populations by sub-basin.

               Table 1--Oregon Chub Population Estimates and Trends (From Bangs et al. 2008, p. 7)
----------------------------------------------------------------------------------------------------------------
                                                                     Population
         Population site name                   Owner \1\           estimate \2\          5-year trend \3\
----------------------------------------------------------------------------------------------------------------
Santiam River Sub-basin:
    Foster Pullout Pond...............  Corps...................           2,640   increasing.
    Gray Slough.......................  Private.................             660   stable.
    South Stayton Pond................  ODFW....................           1,710   .............................
    Geren Island North Channel........  City of Salem...........             210   .............................
    Pioneer Park Backwater............  Private.................             320   .............................
    Stayton Public Works Pond.........  City of Stayton.........              70   .............................
    Santiam I-5 Side Channels.........  ODOT....................              (2)  .............................
    Green's Bridge Slough.............  Private.................              (8)  .............................

[[Page 21182]]

 
    Santiam Easement..................  Private (with USFWS                   (2)  .............................
                                         easement).
Mainstem Willamette Sub-basin
 (includes McKenzie River and Coast
 Fork):
    Ankeny Willow Marsh...............  USFWS...................          36,460   increasing.
    Dunn Wetland......................  Private.................          46,330   stable.
    Finley Gray Creek Swamp...........  USFWS...................           2,140   increasing.
    Finley Cheadle Pond...............  USFWS...................           3,520   increasing.
    Finley Display Pond...............  USFWS...................             830   increasing.
    St. Paul Ponds....................  ODFW....................             (25)  .............................
    Muddy Creek.......................  Private.................              (3)  .............................
    Russell Pond......................  Private.................             650   stable.
    Shetzline Pond....................  Private.................             130   .............................
    Big Island........................  Private.................             200   .............................
    Green Island......................  Private.................             (12)  .............................
    Herman Pond.......................  USFS....................              (3)  .............................
    Coast Fork Side Channels..........  OPRD/ODOT...............             130   .............................
    Sprick............................  Private.................             (12)  .............................
    Lynx Hollow Side Channels.........  OPRD....................              (0)  .............................
Middle Fork Sub-basin:
    Shady Dell Pond...................  USFS....................           7,250   increasing.
    E. Bristow St. Park--Berry Slough.  OPRD....................           5,460   increasing.
    Dexter Reservoir RV Alcove--DEX3..  Corps...................           2,450   stable.
    Wicopee Pond......................  USFS....................           5,430   stable.
    Fall Creek Spillway Ponds.........  Corps...................           3,050   declining.
    Buckhead Creek....................  USFS....................           1,260   declining.
    East Fork Minnow Creek Pond.......  ODOT....................           2,160   stable.
    Elijah Bristow Island Pond........  OPRD....................             550   stable.
    Hospital Pond.....................  Corps...................           3,680   stable.
    Dexter Reservoir Alcove--PIT1.....  Corps...................             680   stable.
    Haws Pond.........................  Private.................             280   .............................
    E. Bristow St. Park--NE Slough....  OPRD....................             230   .............................
    Jasper Park Slough................  OPRD....................              (1)  .............................
    Elijah Bristow South Slough.......  OPRD....................              (1)  .............................
    Middle Fk Willamette RM 198.6.....  OPRD....................              (1)  .............................
    Middle Fk Willamette RM 199.5.....  OPRD....................              (1)  .............................
----------------------------------------------------------------------------------------------------------------
\1\ Owner abbreviations: Corps = U.S. Army Corps of Engineers, USFWS = U.S. Fish and Wildlife Service, USFS =
  U.S. Forest Service, ODOT = Oregon Department of Transportation, OPRD = Oregon Parks and Recreation
  Department, ODFW = Oregon Department of Fish and Wildlife.
\2\ Population numbers are mark-recapture estimates except those shown in parentheses, which are the number of
  fish counted.
\3\ Five-year trends were calculated for abundant populations (>500 individuals for the last 5 years) only.

Additional Conservation Measures

    The Oregon Chub Working Group (Working Group) was formed in 1991. 
This group of Federal and State agency biologists, academicians, land 
managers, and others meet each year to share information on the status 
of the Oregon chub, results of new research, and ongoing threats to the 
species. The Working Group has been an important force in improving the 
conservation status of the Oregon chub.
    An interagency conservation agreement was established for the 
Oregon chub in 1992, prior to listing (U.S. Fish and Wildlife Service 
1998, p. 59). The Service, ODFW, Oregon Department of Parks and 
Recreation, Corps, U.S. Bureau of Land Management, and U.S. Forest 
Service are the parties to the agreement. The objectives of the 
conservation agreement are to: (1) Establish a task force drawn from 
participating agencies to oversee and coordinate Oregon chub 
conservation and management actions, (2) protect existing populations, 
(3) establish new populations, and (4) foster greater public 
understanding of the species, its status, and the factors that 
influence it (U.S. Fish and Wildlife Service 1998, pp. 65-66).
    The Oregon chub is designated as ``Sensitive-Critical'' by ODFW. 
The ``Sensitive'' species classification was created under Oregon's 
Sensitive Species Rule (OAR 635-100-040) to address the need for a 
proactive species conservation approach. The Sensitive Species List is 
a nonregulatory tool that helps focus wildlife management and research 
activities, with the goal of preventing species from declining to the 
point of qualifying as ``endangered'' or ``threatened'' under the 
Oregon Endangered Species Act (ORS 496.171, 496.172, 496.176, 496.182 
and 496.192). Species designated as Sensitive-Critical are those for 
which listing as endangered or threatened would be appropriate if 
immediate conservation actions were not taken. This designation 
encourages, but does not require, implementation of any conservation 
actions for the species; however, other State agencies, such as the 
Oregon Department of State Lands, the Water Resources Department, and 
the Oregon State Marine Board, refer to the Sensitive Species List when 
making regulatory decisions.
    In 2009, the Service developed a programmatic Safe Harbor Agreement 
with ODFW (Oregon Department of Fish and Wildlife and U.S. Fish and 
Wildlife Service 2009, pp. 1-30). A Safe Harbor Agreement is a 
voluntary agreement involving private or other non-Federal property 
owners whose actions contribute to the recovery of species listed as 
endangered or threatened under the Act. In exchange for actions that 
contribute to the recovery of listed species on non-Federal lands, 
participating property owners receive formal assurances from the 
Service that if they fulfill the conditions of the Safe Harbor 
Agreement, the Service will not

[[Page 21183]]

require any additional management activities by the participants 
without their consent. In addition, at the end of the agreement period, 
participants may return the enrolled property to the baseline 
conditions that existed at the beginning of the agreement. The 
programmatic Safe Harbor Agreement allows ODFW to work with private 
landowners to establish new populations of Oregon chub on private 
lands, directly advancing the recovery of the species. The permit, 
authorized under section 10(a)(1)(A) of the Act, associated with the 
programmatic Safe Harbor Agreement authorizes ODFW to extend incidental 
take coverage with assurances to eligible landowners who are willing to 
carry out habitat management measures that would benefit the Oregon 
chub by enrolling them under the agreement as Cooperators through 
issuance of Certificates of Inclusion.

Summary of Comments and Responses

    In conformance with our policy on peer review, published on July 1, 
1994 (59 FR 34270), we solicited the expert opinions of four 
appropriate and independent experts following publication of the 
proposed rule. We received five comment letters on the proposed rule: 
four from peer reviewers and one comment letter from ODFW. All of the 
reviewers were in support of the reclassification, and most recommended 
only minor clarifications to the proposed rule. We have incorporated 
these minor clarifications into this final rule. We received one 
substantive comment, which we summarize and respond to below.
    Comment: One peer reviewer agreed with the Service's proposal to 
reclassify the Oregon chub as threatened, but noted that climate change 
and its effects to the hydrology of the Willamette Basin were not 
addressed in the proposed rule, and suggested that these issues need to 
be evaluated before the Service considers delisting the Oregon chub.
    Our Response: Climate change presents substantial uncertainty 
regarding the future environmental conditions in the Willamette Basin. 
The channelization of the Willamette River and its tributaries, and the 
introduction of nonnative predatory fishes were the major factors 
underlying the historical decline of the Oregon chub. Changing climate 
is expected to place an added stress on the species and its habitats. 
The Intergovernmental Panel on Climate Change (IPCC) has concluded that 
recent warming is already strongly affecting aquatic biological 
systems; this is evident in increased runoff and earlier spring peak 
discharge in many glacier- and snow-fed rivers (IPCC 2007, p. 8). 
Projections for climate change in North America include decreased 
snowpack, more winter flooding, and reduced summer flows (IPCC 2007, p. 
14). Projections for climate change in the Willamette Valley in the 
next century include higher air temperatures that will lead to lower 
soil moisture and increased evaporation from streams and lakes (Climate 
Leadership Initiative (CLI) and the National Center for Conservation 
Science and Policy 2009, p. 9). While there is high uncertainty in the 
total precipitation projections for the region, effective precipitation 
(precipitation that contributes to runoff) may be reduced significantly 
even if there is no decline in total precipitation (CLI and the 
National Center for Conservation Science and Policy 2009, p. 9).
    Although climate change is almost certain to affect aquatic 
habitats in the Willamette Basin (CLI 2009, p. 1), there is great 
uncertainty about the specific effects of climate change on the Oregon 
chub. The Service has developed a strategic plan to address the threat 
of climate change to vulnerable species and ecosystems; goals of this 
plan include maintaining ecosystem integrity by protecting and 
restoring key ecological processes such as nutrient cycling, natural 
disturbance cycles, and predator-prey relationships (U.S. Fish and 
Wildlife Service 2009; p. 21). The Oregon chub recovery program will 
strive to achieve these goals by working to establish conditions that 
allow populations of Oregon chub to be resilient to changing 
environmental conditions and to persist as viable populations into the 
future. Our recovery program for the species focuses on maintaining 
large populations distributed across the species' entire historical 
range in a variety of ecological settings (e.g., across a range of 
elevations). This approach is consistent with the general principles of 
conservation biology. In their review of minimum population viability 
literature, Traill et al. (2009, p. 3) found that maintenance of large 
populations across a range of ecological settings increases the 
likelihood of species persistence under the pressures of environmental 
variation and facilitates the retention of important adaptive traits 
through the maintenance of genetic diversity. Maintaining multiple 
populations across a range of ecological settings, as described in the 
recovery plan, will also increase the likelihood that at least some of 
these populations persist under the stresses of a changing climate.
    Our recovery program will continue to focus on monitoring the 
species' status and responding to changing conditions. Any future 
proposal to delist the species due to recovery will need to establish 
that the species is not likely to become endangered in the foreseeable 
future throughout all or a significant portion of its range in the 
absence of the Act's protections, including consideration of any likely 
effects caused by changing climate.

Summary of Factors Affecting the Species

    Section 4 of the Act and its implementing regulations (50 CFR part 
424) set forth the procedures for listing species, reclassifying 
species, or removing species from listed status. ``Species'' is defined 
by the Act as including any species or subspecies of fish or wildlife 
or plants, and any distinct vertebrate population segment of fish or 
wildlife that interbreeds when mature. Once the ``species'' is 
determined, we then evaluate whether that species may be endangered or 
threatened because of one or more of the five factors described in 
section 4(a)(1) of the Act. We must consider these same five factors in 
reclassifying or delisting a species. For species that are already 
listed as endangered or threatened, this analysis of threats is an 
evaluation of both the threats currently facing the species and the 
threats that are reasonably likely to affect the species in the 
foreseeable future following the delisting or downlisting and the 
removal or reduction of the Act's protections.
    A species is ``endangered'' for purposes of the Act if it is in 
danger of extinction throughout all or a significant portion of its 
range, and is ``threatened'' if it is likely to become endangered 
within the foreseeable future throughout all or a significant portion 
of its range. The word ``range'' is used here to refer to the range in 
which the species currently exists, and the word ``significant'' refers 
to the value of that portion of the range being considered to the 
conservation of the species. The ``foreseeable future'' is the period 
of time over which events or effects reasonably can or should be 
anticipated, or trends reasonably extrapolated; see discussion 
following Factor E, below.
    After completing a rangewide threats analysis, we also evaluate 
whether the Oregon chub is endangered or threatened in any significant 
portion(s) of its range.

[[Page 21184]]

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

    Historical records indicate that the Oregon chub was distributed 
throughout the Willamette Basin, from the Clackamas River in the north, 
to the Coast Fork and Middle Fork in the south (Markle et al. 1991, p. 
288). When we listed the Oregon chub as endangered in 1993, the species 
was known to exist at only nine locations, representing only 2 percent 
of the species' historical range (Markle et al. 1991, pp. 288-289; 
Scheerer et al. 2007, p. 2). Four of these locations had fewer than 10 
individuals (Scheerer et al. 2007, p. 2). This precipitous decline in 
the species' abundance and distribution was attributed to the extensive 
channelization, dam construction, and chemical contamination that 
occurred in the Willamette Basin, particularly from the 1940s through 
the late 20th century (Pearsons 1989, pp. 29-30).
    There are at least 371 dams in the Willamette River Basin, most of 
which were constructed from 1950 through 1980 (Hulse et al. 2002, p. 
30). These dams reduced the magnitude, extent, and frequency of 
flooding in the basin, which dramatically reduced the amount of slough 
and side channel habitats available to the Oregon chub (Hulse et al. 
2002, pp. 28-30). Other structural changes, such as revetment and 
channelization, diking and drainage, and the removal of floodplain 
vegetation, eliminated or altered the side channels and sloughs used by 
the Oregon chub, and destroyed the natural processes that replenish 
these slack water habitats (Hjort et al. 1984, p. 73; Sedell and 
Frogatt 1984, p. 1833; Hulse et al. 2002, p. 27). Analysis of 
historical records shows that over one-half of the Willamette's sloughs 
and alcoves had been lost by 1995 (Hulse et al. 2002, p. 18). Although 
the Oregon chub evolved in a dynamic environment in which flooding 
periodically created and reconnected habitat for the species, currently 
most populations of Oregon chub are isolated from other chub 
populations due to the reduced frequency and magnitude of flood events 
and the presence of migration barriers such as impassable culverts and 
beaver dams (Scheerer et al. 2007, p. 9).
    In the 16 years since we listed the Oregon chub as endangered, 
concerted efforts by Federal, State, and local governments and private 
landowners have increased the number of Oregon chub populations from 9 
to 38 (Scheerer et al. 2007, p. 2; Scheerer 2008a, p. 6; Bangs et al. 
2008, p. 7). This dramatic increase in the number of populations is a 
result of the discovery of new populations through extensive surveys of 
suitable habitats throughout the Willamette Basin and the establishment 
of new populations through successful reintroductions within their 
historical range (Scheerer 2007, p. 97). Since 1992, Oregon chub have 
been reintroduced to 16 locations, resulting in the successful 
establishment of 9 populations (Bangs et al. 2008, p. 7).
    The analysis of threats in the final rule to list the Oregon chub 
as an endangered species and the recovery plan for the species 
discussed numerous potential threats to water quality in Oregon chub 
habitats. Many Oregon chub populations occur near rail, highway, and 
power transmission corridors; near agricultural fields; and within 
public park and campground facilities; prompting concern that these 
populations could be threatened by chemical spills, runoff, or changes 
in water level or flow conditions caused by construction, diversions, 
or natural desiccation (58 FR 53800; U.S. Fish and Wildlife Service 
1998, p. 14, Scheerer 2008c, p. 1). In the 16 years since listing, a 
few of these concerns have been realized, and are discussed in the 
paragraphs below.
    Excessive siltation from ground disturbing activities in the 
watershed, such as logging upstream of Oregon chub habitat, can degrade 
or destroy Oregon chub habitat. The threat of siltation due to logging 
in the watershed has been identified at five sites: Green Island North 
Channel, Finley Gray Creek Swamp, East Fork Minnow Creek Pond, Buckhead 
Creek, and Wicopee Pond (Scheerer 2008c, p. 1). In the 1990s, a large 
part of the Minnow Creek Watershed in the Middle Fork Willamette sub-
basin was logged; flood events in the watershed in 1996, 1997, and 1998 
caused accelerated sedimentation in the beaver pond at East Fork Minnow 
Creek Pond, and over half of the open water wetted area of the Oregon 
chub habitat there was lost as sediment filled the pond (Scheerer 
2009b, p. 1). The Oregon chub population in East Fork Minnow Creek Pond 
declined dramatically following these floods and the resulting 
sedimentation (Scheerer 2009b, p. 1).
    Water quality investigations at sites in the Middle Fork and 
Mainstem Willamette sub-basins have found some adverse effects to 
Oregon chub habitats. Nutrient enrichment may have caused the crash of 
the Oregon chub population at Oakridge Slough on the Middle Fork. The 
slough is downstream from the Oakridge Sewage Treatment Plant and has a 
thick layer of decaying organic matter, which may limit the amount of 
useable habitat available to the chub (Buck 2003, p. 2). In the late 
1990s, the Oregon chub population in Oakridge Slough peaked at nearly 
500 individuals; since then, the population has apparently declined to 
zero (Scheerer et al. 2007, p. 2). Increased nitrogen and phosphorus 
concentrations have been detected in the slough; while the nutrient 
concentrations are not believed to be directly harmful to Oregon chub, 
the elevated nutrient levels may have resulted in eutrophication of the 
pond, with associated anoxic conditions unsuitable for chub, or 
increased plant and algal growth that severely reduced habitat 
availability (Buck 2003, p. 12).
    Studies at William L. Finley National Wildlife Refuge have found 
evidence of elevated levels of nutrients and pesticides in Oregon chub 
habitats (Materna and Buck 2007, p. 67). Water samples were collected 
in 1998 from Gray Creek Swamp, which is home to a large population of 
Oregon chub. Analyses detected three herbicides, although all were 
below criteria levels recommended for protection of aquatic life; 
however, one form of nitrogen (total Kjeldahl N) exceeded Environmental 
Protection Agency (EPA) criteria levels recommended for protection of 
aquatic life in the Willamette Valley (Materna and Buck 2007, p. 67). 
The source of the contamination is likely agricultural runoff from farm 
fields adjacent to the Refuge (Materna and Buck 2007, p. 68). We note 
that EPA's recommended criteria for protection of aquatic life are not 
intended to be protective of all aquatic life, and may not be fully 
protective of the Oregon chub. EPA and the Service are working together 
to assess the effects of pollutants on the Oregon chub through section 
7 consultation on Oregon water quality standards.
    Fluctuating water levels in Lookout Point Reservoir on the Middle 
Fork Willamette River were limiting the breeding success of the Oregon 
chub population in Hospital Pond, which provides habitat for the 
species in a pool connected to the reservoir by a culvert. In 2001, 
2002, and 2003, the Corps, which manages Lookout Point Reservoir, 
implemented a series of projects to protect the population of Oregon 
chub in Hospital Pond. The goal was to allow the Corps to manage the 
water level in Lookout Point Reservoir independently of the water 
elevation in Hospital Pond. The Corps installed a gate on Hospital 
Pond's outlet culvert and lined the porous berm between the pond and 
reservoir; these modifications allow the Corps to maintain the water 
level needed to support Oregon chub

[[Page 21185]]

spawning in Hospital Pond independent of the water level in the 
reservoir (U.S. Fish and Wildlife Service 2002, pp. 1-11). The Corps 
also excavated additional area to create more suitable spawning habitat 
in the pond (U.S. Fish and Wildlife Service 2003, pp. 1-3). The result 
of these management actions has been a large stable population of 
Oregon chub in Hospital Pond (Scheerer 2008a, p. 6).
    Most of the known Oregon chub populations occur on lands with some 
level of protective status and management (see Table 1 above). The 
Service manages several Oregon chub populations on the Finley and 
Ankeny units of the Willamette Valley National Wildlife Refuge Complex 
(Refuge). Recovery of the Oregon chub is a high priority for the 
Refuge. The Refuge actively monitors the status of the populations, 
habitat quality, and nonnative fish presence; when threats are 
detected, the Refuge implements management actions to reverse the 
threats (Smith 2008, p. 1).
    Five populations of Oregon chub occur on lands managed by the 
Corps; the Corps manages Oregon chub in accordance with the Service's 
biological opinion on the Willamette Project. In July 2008, the Corps, 
Bonneville Power Administration (BPA), and Bureau of Reclamation (BOR) 
completed formal consultation with the Service under section 7(a)(2) of 
the Act on the operation and maintenance of the Willamette Project, the 
system of 13 dams and associated impoundments that provide flood 
control, irrigation, municipal and industrial water supply, navigation, 
fish and wildlife conservation, flow augmentation, hydroelectric power 
generation, and recreation to the Willamette Valley. The Service 
concluded that the project would not jeopardize the continued existence 
of the Oregon chub (U.S. Fish and Wildlife Service 2008b, p. 170). The 
Service's biological opinion describes the measures that will be 
implemented by the Corps, BPA, and BOR to maintain and improve habitat 
for the Oregon chub. These measures include:
    (1) Monitoring the status of Oregon chub populations affected by 
operation and maintenance of the dams to gain a better understanding of 
the influence of the Willamette Project on the species;
    (2) Managing water levels in Oregon chub habitats directly affected 
by reservoir operations;
    (3) Relocating Oregon chub from ponds adversely affected by 
reservoir operations to new locations with better prospects for long-
term protection;
    (4) Conducting studies to identify the effects of flow management 
on Oregon chub habitats; and
    (5) Funding a pilot study to investigate the impact of floodplain 
restoration and reconnection on fish communities in river reaches below 
Willamette Project dams.
    Operation and maintenance of the Willamette Project under the new 
biological opinion will result in improved protections for the Oregon 
chub and new information that will benefit the species throughout the 
Willamette Basin.
    The Oregon Department of Transportation has developed and is 
implementing a plan to protect and enhance Oregon chub populations on 
the agency's properties or those which may be affected by highway 
maintenance on the Santiam River, Coast Fork Willamette River, and 
Middle Fork Willamette River (Scheerer 2005, pp. 1-21).
    The Oregon chub populations at Elijah Bristow State Park and Jasper 
Park on the Middle Fork are managed by the Oregon Parks and Recreation 
Department, which uses the Service's recovery plan as guidance to 
ensure conservation of the chub populations within the parks (Schleier 
2008).
    The U.S. Forest Service monitors and manages several Oregon chub 
populations on the Middle Fork (Scheerer 2008b, p. 1).
    In addition to the management and protection provided to the Oregon 
chub on Federal and State lands, two individual Safe Harbor Agreements 
and a new programmatic Safe Harbor Agreement have been completed to 
guide management of Oregon chub populations on private lands. Safe 
Harbor Agreements are voluntary arrangements between the Service and 
cooperating non-Federal landowners to promote management for listed 
species on non-Federal property while giving assurances to 
participating landowners that no additional future regulatory 
restrictions will be imposed. The programmatic Safe Harbor Agreement 
with ODFW (Oregon Department of Fish and Wildlife and U.S. Fish and 
Wildlife Service 2009, pp. 1-30) will substantially contribute to the 
recovery of the Oregon chub.
Summary of Factor A
    The Oregon chub has experienced extensive loss of slough and side-
channel habitat due to hydrological changes resulting from dam 
construction and channelization in the Willamette Valley. However, many 
new habitats have been artificially created and are being managed to 
maintain populations of Oregon chub. There is evidence that some 
populations are threatened by water quality degradation and associated 
reduction in habitat quality, although this has been documented at only 
a few sites. Habitat conditions have improved to the point where the 
species is not presently in danger of extinction. However, without the 
continued protections provided by the Act, or long-term management 
agreements, the Oregon chub would likely become endangered in the 
foreseeable future due, in part, to the destruction, modification, or 
curtailment of its habitat. In addition, a changing climate is expected 
to place an added stress on the species and its habitats, although 
there is substantial uncertainty regarding the future environmental 
conditions in the Willamette Basin (see Summary of Comments and 
Responses section, above).

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

    Overutilization for commercial, recreational, scientific, or 
educational purposes was not a factor in listing, nor is it currently 
known to be a threat to the Oregon chub.

Factor C. Disease or Predation

    The proliferation of predatory, nonnative fish is the most 
significant current threat to Oregon chub populations (Scheerer et al. 
2007, p. 14). The basin contains 31 native fish species and 29 
nonnative species (Hulse et al. 2002, p. 44). The large-scale 
alteration of the Willamette Basin's hydrologic system (i.e., 
construction of dams and the resultant changes in flood frequency and 
intensity) has created conditions that favor nonnative, predatory 
fishes, and reservoirs throughout the basin have become sources of 
continual nonnative fish invasions in the downstream reaches (Li et al. 
1987, p. 198).
    Oregon chub are most abundant at sites where nonnative fishes are 
absent (Scheerer 2007, p. 96). Predatory, nonnative centrarchids (bass 
and sunfish) and Ameiurus spp. (bullhead catfish) are common in the 
off-channel habitats used by Oregon chub (Scheerer 2002, p. 1075). 
Sites with high connectivity to adjacent flowing water frequently 
contain nonnative, predatory fishes and rarely contain Oregon chub 
(Scheerer 2007, p. 99). The presence of centrarchids and bullhead 
catfishes is probably preventing Oregon chub from recolonizing 
otherwise suitable habitats throughout the basin (Markle et al. 1991, 
p. 291).

[[Page 21186]]

    Management for Oregon chub has focused on establishing secure, 
isolated habitats free of nonnative fishes. However, natural flood 
events may breach barriers to connectivity allowing invasion by 
nonnative fishes. During the 1996 floods in the Willamette Basin, 
nonnative fishes invaded the habitats of the two largest Oregon chub 
populations in the Santiam River (Geren Island North Channel and 
Santiam Easement). In the next 2 years, these populations declined by 
more than 50 percent, and have not recovered to pre-1996 levels more 
than 10 years later (Scheerer 2002, p. 1078; Bangs et al. 2008, p. 7).
    Game fish have also been intentionally introduced into chub ponds. 
An illegal introduction of largemouth bass (Micropterus salmoides) at 
an Oregon chub population site on the Middle Fork apparently caused a 
significant decline in that population from over 7,000 fish to 
approximately 3,000 fish from 2000 to 2008 (Scheerer et al. 2007, p. 
14; Bangs et al. 2008, p. 7). The ubiquity of nonnative fishes in the 
Willamette Basin has created a substantial challenge to the recovery of 
the Oregon chub. Scheerer et al. (2007, pp. 10-14) conclude, ``The 
resulting paradox is that the frequent interaction of the river with 
the floodplain habitats * * *, conditions which historically created 
off-channel habitats and aided in the dispersal of chub and the 
interchange of individuals among populations, now poses a threat to 
Oregon chub by allowing dispersal of nonnative species.''
    Nonnative fishes may also serve as sources of parasites and 
diseases for the Oregon chub. However, disease and parasite problems 
have not been identified in this species, nor has the issue been 
studied.
Summary of Factor C
    Predatory, nonnative fishes are the most significant current threat 
to the recovery of the Oregon chub. Nonnative fishes are abundant and 
ubiquitous in the Willamette River Basin, and continual monitoring and 
management are required to protect existing Oregon chub populations 
from invasion. Predation remains a concern, but as the status of the 
species has improved since listing (i.e., more populations have been 
established and are being managed to minimize threats), the relative 
effect of the threat of predatory, nonnative fishes has declined. 
Nevertheless, predation continues to impact the Oregon chub such that 
it is likely to become endangered in the foreseeable future without 
continued protection under the Act.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Before we listed the Oregon chub as endangered in 1993, the species 
had no regulatory protections. Upon its listing as endangered, the 
species benefited from the protections of the Act, which include the 
prohibition against take and the requirement for interagency 
consultation for Federal actions that may affect the species. Section 9 
of the Act and Federal regulations prohibit the take of endangered and 
threatened species without special exemption. The Act defines ``take'' 
as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or 
collect, or to attempt to engage in any such conduct (16 U.S.C. 
1532(19)). Our regulations define ``harm'' to include significant 
habitat modification or degradation that results in death or injury to 
listed species by significantly impairing essential behavioral 
patterns, including breeding, feeding, or sheltering (50 CFR 17.3). Our 
regulations also define ``harass'' as intentional or negligent actions 
that create the likelihood of injury to listed species to such an 
extent as to significantly disrupt normal behavior patterns, which 
include, but are not limited to, breeding, feeding, or sheltering (50 
CFR 17.3).
    Section 7(a)(1) of the Act requires all Federal agencies to utilize 
their authorities in furtherance of the purposes of the Act by carrying 
out programs for the conservation of endangered species and threatened 
species. Section 7(a)(2) of the Act requires Federal agencies to ensure 
that any action they authorize, fund, or carry out is not likely to 
jeopardize the continued existence of listed species or adversely 
modify their critical habitat. Thus, listing the Oregon chub provided a 
variety of protections, including the prohibition against take and the 
conservation mandates of section 7 for all Federal agencies. Because 
the Service has regulations that prohibit take of all threatened 
species (50 CFR 17.31(a)), unless modified by a special rule issued 
under section 4(d) of the Act (50 CFR 17.31(c)), the regulatory 
protections of the Act are largely the same for species listed as 
endangered and as threatened; thus, the protections provided by the Act 
will remain in place if the Oregon chub is reclassified as a threatened 
species.
    The Oregon chub is designated as ``Sensitive-Critical'' by ODFW. 
This designation is a nonregulatory tool that helps focus wildlife 
management and research activities, with the goal of preventing species 
from declining to the point of qualifying as ``threatened'' or 
``endangered'' under the Oregon Endangered Species Act (ORS 496.171, 
496.172, 496.176, 496.182 and 496.192). Sensitive-Critical designation 
encourages, but does not require, the implementation of any 
conservation actions for the species; however other State agencies, 
such as the Oregon Department of State Lands, the Water Resources 
Department, and the Oregon State Marine Board, refer to the Sensitive 
Species List when making regulatory decisions.
    The Oregon chub is not protected by any other regulatory 
mechanisms.
Summary of Factor D
    The regulatory mechanisms in effect under the Act provide a 
prohibition against take, the affirmative conservation mandate of 
section 7(a)(1), and the duty of all Federal agencies to avoid 
jeopardizing the continued existence/destroying or adversely modifying 
critical habitat of section 7(a)(2); these regulatory mechanisms will 
remain in place with the Oregon chub's downlisting to threatened. A 
program of conservation actions will be implemented by the Corps, BPA, 
and BOR as a result of the Service's biological opinion on the 
Willamette Project. However, because there are no other regulatory 
mechanisms in place beyond the Act, the inadequacy of regulatory 
mechanisms still threatens the Oregon chub.

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

    Almost half of all the fish species in the Willamette River are not 
native to the basin (Hulse et al. 2002, p. 44). Along with the direct 
threat of predation (see Factor C, above), nonnative fish compete with 
Oregon chub for food resources. Competition with nonnative fishes may 
contribute to the decline and exclusion of Oregon chub from suitable 
habitats. The observed feeding strategies and diets of nonnative 
fishes, particularly juvenile centrarchids and adult mosquitofish 
(Gambusia affinis), overlap with the diet and feeding strategies 
described for the Oregon chub (Li et al. 1987, pp. 197-198). Thus, 
direct competition for food between Oregon chub and nonnative species 
may limit the distribution and expansion of the species; however, no 
studies have focused on the topic of competitive exclusion to date.
    Historically, floods provided the mechanism of dispersal and 
genetic exchange for Oregon chub populations throughout the Willamette 
Basin (Scheerer 2002, p. 1078). The current management focus on 
protecting Oregon

[[Page 21187]]

chub populations in isolation, which protects the species from the 
introduction of predatory, nonnative fishes, may be having negative 
genetic implications (Scheerer 2002, p. 1078). This lack of 
connectivity means that movement of individuals among populations 
occurs rarely, if at all, which results in little or no genetic 
exchange among populations (Scheerer et al. 2007, p. 9). Research is 
under way to determine if Oregon chub populations have distinct genetic 
characteristics in the different sub-basins of the Willamette River; 
preliminary results seem to indicate that genetic differences exist 
among the major sub-basins of the Willamette Basin (Ardren et al. 2008, 
p. 1). There is concern that an unintended effect of managing for 
isolated populations may be genetic drift and inbreeding. If this 
proves to be the case, managers may need to move fish among populations 
to fulfill the role that natural flooding once played (Scheerer et al. 
2007, p. 15).
Summary of Factor E
    Competition from nonnative species and the potential loss of 
genetic diversity as a result of managing Oregon chub populations in 
isolated habitats are threats that could affect Oregon chub populations 
throughout the species' range. However, the magnitude of these threats 
is unknown.

Conclusion of 5-Factor Analysis

    We have carefully assessed the best scientific and commercial data 
available and have determined that the Oregon chub is not currently in 
danger of extinction. We believe that the species now meets the 
definition of a threatened species throughout all of its range. It has 
exceeded two of the downlisting criteria and is on the brink of meeting 
the third. Recovery plans are intended to guide and measure recovery. 
Recovery criteria for downlisting and delisting are developed in the 
recovery planning process to provide measurable goals on the path to 
recovery; however, precise attainment of all recovery criteria is not a 
prerequisite for downlisting or delisting. Rather, the decision to 
revise the status of a listed species is based solely on the analysis 
of the five listing factors identified in section 4 of the Act. The Act 
provides for downlisting from endangered to threatened when the best 
available data indicate that a species, subspecies, or distinct 
population segment is no longer in danger of extinction, but is likely 
to become endangered in the foreseeable future without the continued 
protection of the Act.
    At the time we completed the Oregon Chub Recovery Plan in 1998, we 
attempted to describe what the range, abundance, and distribution of 
Oregon chub populations should be before downlisting and delisting. 
These estimates were manifested in the downlisting and delisting 
criteria discussed above, and these criteria effectively established 
the Service's position on what constitutes ``threatened'' for the 
Oregon chub, in the case of downlisting criteria, and ``recovered,'' in 
the case of the delisting criteria. Because the downlisting criteria 
have not been precisely met, the finding in this rule represents a 
departure from the Service's previously articulated description of 
``threatened'' for the Oregon chub, and so must be further explained.
    We compared current Oregon chub population information with the 
downlisting criteria for each sub-basin and estimated the amount by 
which each population goal's had been exceeded. The result of this 
comparison is shown in Table 2.

    Table 2--Comparison of Numerical Population Goals for Downlisting From the Oregon Chub Recovery Plan With
        Current Population Estimates, by Sub-basin (Current Population Data From Bangs et al. 2008, p. 7)
----------------------------------------------------------------------------------------------------------------
                                                                                      Current       Percent of
                                                                    Downlisting     population      downlisting
                                                                   goal (number      estimate      goal achieved
                            Sub-basin                             of fish/number    (number of      (number of
                                                                        of        fish/number of  fish/number of
                                                                   populations)    populations)    populations)
----------------------------------------------------------------------------------------------------------------
Santiam.........................................................         1,500/3         5,622/9         375/300
Mainstem Willamette.............................................         1,500/3       90,442/13       6,029/433
Middle Fork Willamette..........................................         1,500/3       32,484/16       2,166/533
----------------------------------------------------------------------------------------------------------------

    Although these totals do not incorporate the 5-year stable or 
increasing trend aspect of the downlisting criteria, the number of chub 
in these basins greatly exceeds the minimum required in the downlisting 
criteria for both the number of populations and the number of 
individual fish. Taken together, along with the 5-factor analysis 
discussed above, it is clear that the status of the chub is far more 
secure than it might be with 4,500 fish in 9 populations across 3 sub-
basins with 5-year stable or increasing trends.
    The number of populations has increased from 9 to 38 since we 
listed the species in 1993; there are 16 large (>500 individuals) 
populations with stable or increasing trends. The species is well 
distributed throughout the Willamette Basin, and most of these 
populations have some type of protective management and appear to be 
viable as long as they are monitored and adaptively managed. Although 
many of the threats have been reduced by recovery efforts, threatened 
status is appropriate because the species is likely to become 
endangered in the foreseeable future without the protections of the Act 
or long-term management agreements and adaptive management actions. In 
addition, concerns remain regarding the genetic implications of 
managing Oregon chub in isolated ponds, cut off from potential 
interactions with other populations in the basin.
    Threats to existing habitats remain, including manipulation of 
flows which can lead to desiccation, nutrient and pesticide runoff, and 
vegetative succession in shallow pond environments. The chief threat to 
existing Oregon chub populations is nonnative fish invasions, which may 
occur as a result of flood events, intentional introductions, or 
through connections between isolated chub habitats and adjacent 
watercourses. However, as the status of the species has improved since 
listing (i.e., more populations have been established and are being 
managed to minimize threats), the relative effect of the threat of 
predatory nonnative fishes has declined. Monitoring for nonnative fish 
invasions and adaptively managing in response to such invasions is 
necessary for the long-term viability of this species.

[[Page 21188]]

    In the absence of the Act's regulatory protections, predation by 
nonnative fishes, as well as population declines and range contraction 
resulting from habitat loss are expected to continue. We have no 
information to suggest that the threats identified above are likely to 
be reduced in the foreseeable future. We also do not have any 
indication that regulatory mechanisms will materialize to address or 
ameliorate the ongoing threats to the species. Thus, future Oregon chub 
population declines and range contraction, similar to what has been 
observed in the past, is a reasonable expectation without the continued 
protections of the Act.
    Having determined that the Oregon chub is threatened throughout its 
range, we must next determine if the species is endangered in any 
significant portion of its range. The primary remaining threats to the 
species are introduction of predatory, nonnative fishes into chub ponds 
and water quality degradation. Extensive surveys of the Willamette 
Basin have found that predatory, nonnative fishes are abundant and 
widespread in each of the sub-basins (Scheerer 2007, p. 97). Threats to 
water quality, including chemical spills, agricultural runoff, and 
drought, are not restricted to any portion of the Oregon chub's range, 
and are equally likely to occur in any of the three sub-basins. While 
the threats associated with reduced genetic exchange among populations 
are not yet well understood it seems likely that the potential genetic 
consequences of management for isolated populations (e.g., inbreeding 
and genetic drift) would be experienced across the range of the 
species, as protection of isolated ponds is the management goal for 
populations in all three of the sub-basins.
    In summary, the primary threats to the Or