Endangered and Threatened Wildlife and Plants; Removal of the Modoc Sucker From the Federal List of Endangered and Threatened Wildlife, 76235-76249 [2015-30915]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 80, Number 235 (Tuesday, December 8, 2015)]
[Rules and Regulations]
[Pages 76235-76249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-30915]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2013-0133; 4500030113]
RIN 1018-AY78


Endangered and Threatened Wildlife and Plants; Removal of the 
Modoc Sucker From the Federal List of Endangered and Threatened 
Wildlife

AGENCY:  Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), are removing 
the Modoc sucker (Catostomus microps) from the Federal List of 
Endangered and Threatened Wildlife. This determination is based on a 
thorough review of the best available scientific and commercial 
information, which indicates that the threats to this species have been 
eliminated or reduced to the point that the species no longer meets the 
definition of an endangered species or a threatened species under the 
Endangered Species Act of 1973, as

[[Page 76236]]

amended (Act). Because we are removing the Modoc sucker from the List 
of Endangered and Threatened Wildlife, we are also removing the 
designated critical habitat for this species. In addition, we are 
making available the final post-delisting monitoring plan for the 
species.

DATES: This rule is effective January 7, 2016.

ADDRESSES: This rule: This final rule is available on the Internet at 
https://www.regulations.gov and https://www.fws.gov/klamathfallsfwo/. 
Comments and materials we received, as well as supporting documentation 
we used in preparing this rule, are available for public inspection at 
https://www.regulations.gov under Docket No. FWS-R8-ES-2013-0133. All of 
the comments, materials, and documentation that we considered in this 
rulemaking are available by appointment, during normal business hours 
at: U.S. Fish and Wildlife Service, Klamath Falls Fish and Wildlife 
Office, 1936 California Avenue, Klamath Falls, OR 97601; by telephone 
541-885-8481; or by facsimile 541-885-7837.
    The post-delisting monitoring plan: The post-delisting monitoring 
plan for the Modoc sucker is available on our Endangered Species 
Program's national Web site (https://endangered.fws.gov), on the Klamath 
Falls Fish and Wildlife Office Web site (https://www.fws.gov/klamathfallsfwo), and on the Federal eRulemaking Portal (https://www.regulations.gov).

FOR FURTHER INFORMATION CONTACT: Laurie Sada, Field Supervisor, U.S. 
Fish and Wildlife Service, Klamath Falls Fish and Wildlife Office, 1936 
California Avenue, Klamath Falls, OR 97601; by telephone 541-885-8481; 
or by facsimile 541-885-7837. Persons who use a telecommunications 
device for the deaf (TDD) may call the Federal Information Relay 
Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Previous Federal Actions

    The Modoc sucker was added to the List of Endangered and Threatened 
Wildlife on June 11, 1985, as an endangered species (50 FR 24526). 
Critical habitat for the species was designated at the time of listing. 
A recovery plan was adopted for the species in 1992. On June 4, 2012, 
we published in the Federal Register a 90-day finding (77 FR 32922) for 
a 2011 petition to reclassify the species from an endangered species to 
a threatened species. In our 90-day finding, we determined that the 
2011 petition provided substantial information indicating the 
petitioned action may be warranted, and we initiated a status review 
for Modoc sucker. On February 13, 2014, we published in the Federal 
Register a combined 12-month finding and proposed rule (79 FR 8656) to 
remove the Modoc sucker from the Federal List of Endangered and 
Threatened Wildlife. On February 13, 2015, we published a document in 
the Federal Register (80 FR 8053) that reopened the public comment 
period on the February 13, 2014, proposed rule. Please refer to the 
February 13, 2014, proposed rule for a detailed description of previous 
Federal actions concerning this species.

Background

    Please refer to the February 13, 2014, proposed rule (79 FR 8656) 
for a summary of background information on the Modoc sucker's taxonomy, 
life history, and distribution. A completed scientific analysis is 
presented in detail in the Modoc Sucker Species Report (Service 2015a, 
entire) (Species Report), which is available at https://www.regulations.gov at Docket Number FWS-R8-ES-2013-0133. The Species 
Report was prepared by Service biologists to provide a thorough 
discussion of the species' ecology and biological needs, and an 
analysis of the stressors that may be impacting the species. For a 
detailed discussion of biological information on the Modoc sucker, 
please see the ``Background'' section of the Species Report, which has 
been updated since the proposed rule and includes discussions on 
taxonomy and species description, habitat, biology, and distribution 
and abundance of the species (Service 2015a, p. 4-14).

Range of the Species

    We consider the ``range'' of Modoc sucker to include an estimated 
42.5 mi (68.4 km) of occupied habitat in 12 streams in the Turner 
Creek, Ash Creek, and Goose Lake sub-basins of the Pit River in 
northeastern California. This amount has increased substantially since 
the time of listing, when the known distribution of Modoc sucker was 
limited to an estimated 12.9 mi (20.8 km) of occupied habitat in seven 
streams in the Turner Creek and Ash Creek sub-basins. This distribution 
represents its entire known historical range, with the exception of 
Willow Creek within the Ash Creek sub-basin. Previous reports of Modoc 
suckers in Willow Creek are based on limited and unverifiable reports 
(Reid 2009, p. 14), and their present existence in Willow Creek remains 
questionable (Reid 2008a, p. 25). Therefore, we consider the confirmed 
historical range to be occupied.

Summary of Changes From the Proposed Rule

    We have not made any substantive changes in this final rule based 
on the comments that we received during the public comment period, but 
we have added or corrected text to clarify the information which we 
presented. One peer reviewer provided information on hybridization 
between Modoc suckers and Sacramento suckers (Catostomus occidentalis). 
This information and other clarifications have been incorporated into 
the Species Report for the species as discussed below in the Summary of 
Comments and Recommendations section.

Recovery and Recovery Plan Implementation

    Section 4(f) of the Act directs us to develop and implement 
recovery plans for the conservation and survival of endangered and 
threatened species unless we determine that such a plan will not 
promote the conservation of the species. At the time of listing, the 
Service, the California Department of Fish and Wildlife (CDFW), and the 
U.S. Forest Service (USFS) were developing an ``Action Plan for the 
Recovery of the Modoc sucker'' (Action Plan). The April 27, 1983, 
Action Plan was formally signed by all participants in 1984 (Service 
1984, entire). The Action Plan was revised in 1989 (Service 1989, 
entire). We determined that the Action Plan and its 1989 revision 
(Service 1984, 1989) adequately fulfilled the requirements of a 
recovery plan, and in a 1992 memorandum from the Regional Director 
(Region 1) to the Service's Director, we adopted it as the recovery 
plan for the Modoc sucker (``1992 Recovery Plan''; Service 1992) and 
determined we would not prepare a separate recovery plan pursuant to 
section 4(f) of the Act.
    The 1992 Recovery Plan included downlisting and delisting 
objectives (considered to be equivalent to criteria). In the February 
13, 2014, proposed rule (79 FR 8656), we outlined the objectives to 
reclassify the Modoc sucker from an endangered species to a threatened 
species and the objectives to remove the Modoc sucker from the List of 
Endangered and Threatened Wildlife, and we discussed progress towards 
meeting the objectives. Please see the February 13, 2014, proposed rule 
for a detailed discussion of the downlisting and delisting objectives 
and how they apply to the status of the Modoc sucker. The objectives 
are summarized below.

[[Page 76237]]

Downlisting Objectives

    Downlisting objective 1: Maintain the integrity of extant habitats 
and prevent the invasion of Sacramento suckers into isolated stream 
reaches of the Turner-Hulbert-Washington Creek system and upper Johnson 
Creek. The intent of meeting this objective was to halt the threat of 
further loss and degradation of habitat (Factor A) and to address the 
threat of genetic introgression from hybridization with Sacramento 
sucker (Factor E).
    Downlisting objective 2: Restore and maintain the quality of 
aquatic habitat conditions within these watersheds and thereby increase 
their carrying capacity for Modoc suckers. The intent of this objective 
was to further address habitat loss and degradation (Factor A) through 
active restoration, with the ultimate goal to allow the habitat to 
support an increase in population numbers.
    Downlisting objective 3: Secure populations of Modoc sucker have 
been maintained in these creeks for 3 consecutive years. The intent of 
this objective was to monitor Modoc sucker populations to ensure 
recruitment had occurred and is based on the life history of Modoc 
suckers, in which individuals mature at age 2+ years.

Delisting Objectives

    Delisting objective 1: The remaining suitable, but presently 
unoccupied, stream reaches within Turner-Hulbert Creek-Washington Creek 
and Rush-Johnson Creek drainages must be renovated and restored to 
Modoc sucker. The intent of this objective was to further address 
habitat loss and degradation (Factor A) through active restoration, as 
well as to increase population sizes and resiliency.
    Delisting objective 2: Secure populations of Modoc suckers must be 
reestablished in at least two other streams outside of the above 
drainages, but within the historical range. The intent of this 
objective was to increase both habitat available and the number of 
populations, thereby increasing redundancy of the Modoc sucker 
populations.
    Delisting objective 3: All populations must have sustained 
themselves through a climactic cycle that includes drought and flood 
events. The intent of this objective was to determine if Modoc suckers 
have responded positively to habitat protection and restoration, and 
have a sufficient number of populations and individuals to withstand 
and recover from environmental variability and stochastic events.
    Since the time of listing, actions have been taken to maintain or 
improve Modoc sucker habitat within Turner Creek, Hulbert Creek, 
Washington Creek, and Johnson Creek in support of downlisting 
objectives 1 and 2. The Service and partners have implemented projects 
and management that maintain the integrity of extant habitat 
(downlisting objective 1) and restore and maintain the quality of 
habitat (downlisting objective 2) via effective stabilization of stream 
banks, fencing to exclude livestock grazing in riparian areas, 
restoration of riparian vegetation, and increased instream habitat. On 
public lands, 1.5 miles (mi) (2.4 kilometers (km)) of Washington Creek, 
0.2 mi (0.3 km) of Hulbert Creek, 0.5 mi (0.8 km) of Coffee Mill Creek, 
and approximately 1.5 mi (2.4 km) of Turner Creek have been fenced to 
protect riparian habitat (Reid 2008a, p. 85; M. Yamagiwa, USFS, 
personal communication). Additionally, since the Modoc sucker was 
listed in 1985, fencing has been constructed to exclude cattle on Rush 
Creek and Johnson Creek below Higgins Flat (Modoc National Forest). 
Fencing led to immediately protecting extant habitat (immediate, near-
term), and allowed habitat to recover. This improved the quality and 
carrying capacity in the long term, thus addressing downlisting 
objectives 1 and 2. Extensive landowner outreach by the Service, USFS, 
and State agencies (CDFW, Oregon Department of Fish and Wildlife 
(ODFW)), and improved livestock grazing management practices in Modoc 
and Lassen Counties, have also resulted in improved protection of 
riparian corridors on private lands in the Turner and Ash Creek sub-
basins. Protection of riparian habitat by excluding cattle and by 
improving livestock grazing management practices on both public and 
private lands has resulted in improved habitat conditions along these 
streams as a result of reduced erosion and improved vegetative and 
hydrologic characteristics (Reid 2008a, pp. 41, 85-86).
    Active habitat restoration (downlisting objective 2) has been 
implemented in many locations throughout the species' range since the 
species was listed. Restoration on the Modoc National Forest has led to 
improved habitat conditions in riparian areas along many of the streams 
occupied by Modoc suckers. Willows have been planted along portions of 
streams occupied by Modoc suckers in the Turner Creek and Ash Creek 
sub-basins to stabilize streambanks and provide shading and cover (Reid 
2008a, pp. 85-86; USFS 2008, p. 16). As a result of riparian habitat 
improvements and improved livestock grazing management practices, 
channel widths have narrowed and created deeper habitat preferred by 
Modoc suckers (USFS 2008, p. 16). Other habitat restoration activities 
include juniper revetment (the use of cut juniper trees to stabilize 
streambanks), creation and expansion of pool habitat, placement of 
boulders within streams to provide cover and shade, and restoration of 
channel headcuts (areas of deep erosion) to prevent further downcutting 
of channels (Reid 2008a, pp. 85-86; USFS 2008, p. 16).
    Habitat conditions in designated critical habitat and other 
occupied streams have steadily improved since listing and have 
sustained populations of Modoc suckers for at least 25 years, although 
recent habitat surveys indicate erosion and sedimentation continue to 
be a problem along lower Turner Creek. However, this degraded reach 
amounts to only 2.4 percent (1.01 mi (1.63 km)) of the total length 
(42.5 mi (68.4 km)) of streams occupied by Modoc sucker. Land 
management practices employed on public and private lands since the 
early 1980s are expected to continue, or improve, thereby maintaining 
stable to upward habitat trends. Thus, we have determined that the 
integrity of extant habitat has been maintained (part of downlisting 
objective 1) and the quality of habitat has been restored and 
maintained through restoration efforts (downlisting objective 2), and 
we conclude that these portions of the downlisting objectives have been 
met.
    While part of downlisting objective 1 was to prevent invasion of 
Sacramento sucker, further research into the magnitude and consequences 
of genetic introgression with Sacramento suckers has led us to conclude 
that this part of the objective is no longer relevant. Observed levels 
of genetic introgression by Sacramento suckers in streams dominated by 
Modoc suckers are low (Smith et al. 2011, pp. 79-83), even when there 
are no physical barriers between the two species (Topinka 2006, pp. 64-
65). This suggests that either ecological differences, selective 
pressures, or other natural reproductive-isolating mechanisms are 
sufficient to maintain the integrity of the species, even after more 
than a century of habitat alteration by human activities. Currently, 
only Ash Creek exhibits a considerable degree of introgression. 
Scientists who have studied suckers in western North America consider 
that, throughout their evolutionary history, hybridization among 
sympatric native fishes is not unusual and may actually provide an 
adaptive advantage (Dowling and Secor 1997, pp. 612-613; Dowling

[[Page 76238]]

2005, p. 10; Topinka 2006, p. 73; Tranah and May 2006, p. 313). 
Reexamination of information on natural barriers, information on 
morphological characters, and new genetic information that was 
unavailable at the time of listing indicates that hybridization is not 
a threat to the Modoc sucker and may be part of its natural 
evolutionary history. Thus, because of the new information that has 
become available since the time of listing, we have determined this 
portion of the downlisting criterion (to prevent the invasion of 
Sacramento suckers) is not a valid concern for the conservation of the 
species and no longer needs to be met for Modoc sucker recovery.
    Several estimates of population size of Modoc suckers in Turner 
Creek, Hulbert Creek, Washington Creek, and Johnson Creek have been 
completed since the 1970s, and found that Modoc sucker populations have 
been maintained in the Turner-Hulbert-Washington Creek system and upper 
Johnson Creek for 3 consecutive years (downlisting objective 3). Modoc 
suckers appear broadly distributed throughout suitable habitat in these 
streams. Although the observations during each survey may not be 
directly comparable due to differences in sampling methods, there does 
not appear to be any major changes in observations of these stream 
populations over time. Observations of Modoc suckers in Hulbert Creek 
and Johnson Creek prior to 2008 appear to be greater than observations 
made in 2008 and 2012. However, this may be explained by differences in 
survey methods, inclusion of young-of-the-year suckers in earlier 
counts, and the fact that some numbers reported are population 
estimates rather than counts of individuals. Although population 
monitoring has not been conducted on an annual basis, sucker surveys 
conducted in 2008 and 2012 show that Modoc sucker populations have been 
maintained, and are still well-established, in Turner Creek, Washington 
Creek, Hulbert Creek, and Johnson Creek--as well as in each of the 
other streams known to be occupied at the time of listing--more than 25 
years after listing. Thus, we have determined that populations of Modoc 
sucker have demonstrated persistence, have had successful recruitment 
(given that individuals mature at 2+ years), and remain stable over 
this timeframe. As a result we conclude that downlisting objective 3 
has been met.
    At the time of listing in 1985, it was estimated that Modoc suckers 
occupied 2.0 mi (3.2 km) of habitat in Turner Creek, 0.8 mi (1.3 km) of 
habitat in Hulbert Creek, 0.5 mi (0.8 km) of habitat in Washington 
Creek, 4.6 mi (7.4 km) in Rush Creek, and 1.2 mi (1.9 km) of habitat in 
Johnson Creek (Reid 2008a, p. 25) (50 FR 24526). Since the time of 
listing, Reid (2008a, p. 25) estimated that there was 5.5 mi (8.9 km) 
of available habitat in Turner Creek, 3.0 mi (4.8 km) in Hulbert Creek, 
4.1 mi (6.6 km) in Washington Creek, 4.6 mi (7.4 km) in Rush Creek, and 
2.7 mi (4.3 km) in Johnson Creek. Habitat conditions along Turner 
Creek, Hulbert Creek, Washington Creek, and Johnson Creek have improved 
since the time of listing. Modoc suckers currently occupy all available 
habitats within Turner Creek, Hulbert Creek, Rush Creek, and Johnson 
Creek; Modoc suckers occupy 3.4 mi (5.5 km) of the available habitat in 
Washington Creek (Reid 2008a, p. 25). Therefore, we have determined 
that delisting objective 1, restoring Modoc suckers to unoccupied 
habitat, has been met.
    The 1992 Recovery Plan stated that additional populations were 
needed to provide population redundancy (delisting objective 2). New 
information indicates the presence of Modoc sucker populations in four 
streams that were not known to be occupied at the time of listing 
(Garden Gulch Creek in the Turner Creek sub-basin; and Thomas Creek, an 
unnamed tributary to Thomas Creek, and Cox Creek in the Goose Lake sub-
basin). In addition, in 1987, CDFW transplanted Modoc suckers from 
Washington Creek to Coffee Mill Creek to establish an additional 
population in the Turner Creek sub-basin (CDFW 1986, p. 11). In those 
four populations, Modoc suckers appear to be well-established and 
relatively abundant; spawning adult and juvenile suckers have been 
consistently observed there during visual surveys (Reid 2009, p. 25). 
Therefore, we have determined that the intent of delisting objective 2 
has been met by the discovery of Modoc sucker populations in additional 
locations and the establishment of one population.
    The northwestern corner of the Great Basin where the Modoc sucker 
occurs is naturally subject to extended droughts, during which even the 
larger water bodies such as Goose Lake have dried up (Laird 1971, pp. 
57-58). Regional droughts have occurred every 10 to 20 years in the 
last century (Reid 2008a, pp. 43-44). Collections of Modoc suckers from 
Rush Creek and Thomas Creek near the end of the ``dustbowl'' drought of 
the 1920s to 1930s (Hubbs 1934, p. 1; Reid 2008a, p. 79) indicate that 
the species was able to persist in those streams even through a 
prolonged and severe drought. Modoc suckers have persisted throughout 
the species' historical range since the time it was listed in 1985, 
even though the region has experienced several pronounced droughts as 
well as heavy-precipitation, high-water years (for example, 2011), 
indicating that the species is at least somewhat resilient to weather 
and hydrologic fluctuations. Therefore, we have determined that 
delisting objective 3 has been met.
    The 1992 Recovery Plan was based on the best scientific and 
commercial information available at the time. In evaluating the extent 
to which recovery objectives have been met, we must also assess new 
information that has become available since the species was listed and 
the 1992 Recovery Plan adopted. As noted above, research and new 
information since the time of listing and the completion of the 1992 
Recovery Plan indicate that hybridization and introgression with 
Sacramento sucker is not a substantial threat to Modoc suckers. 
Additionally, Modoc suckers were found occupying areas they were not 
known to occupy at the time of listing. This new information alters the 
extent to which the recovery objectives related to hybridization and 
establishing new populations need to be met. In the case of 
hybridization and genetic introgression, we find that this objective is 
no longer relevant given the lack of threat to the species. With regard 
to the objective to establish new populations, we find that the 
discovery of additional populations has substantially met the intent of 
the objective to provide for population redundancy so that 
reestablishing two additional populations is no longer needed.
    Additionally, we have assessed whether the 1992 Recovery Plan 
adequately addresses all the factors affecting the species. The 
recovery objectives did not directly address predation by brown trout 
(Salmo trutta) and other nonnative fish or the point at which that 
threat would be ameliorated, although actions to address these threats 
were included in the plan. Since the time of listing, additional 
predatory nonnative fish have been recorded in streams containing Modoc 
suckers. Actions to address nonnative predatory species and an 
assessment of their impact are discussed below. While not specific to 
predatory nonnative fish, attainment of delisting objective 3, 
indicating that Modoc sucker populations have sustained themselves 
since listing in 1985, provides some indication that nonnative 
predatory fish are no longer a serious threat to the species' 
persistence. Effects of climate change is an additional threat 
identified since listing and preparation of the 1992 Recovery Plan. All 
threats, including those identified since listing and

[[Page 76239]]

preparation of the 1992 Recovery Plan, are discussed further later in 
this rule. Based on our analysis of the best available information, we 
conclude that the downlisting and delisting objectives have been 
substantially met. Additional threats not directly addressed in the 
recovery objectives are discussed below. Additional information on 
recovery and the 1992 Recovery Plan's implementation is described in 
the ``Recovery'' section of the Species Report (Service 2015a, pp. 30-
33).

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 population segment of any species of 
vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 
1532(16)). A species may be determined to be an endangered or 
threatened species because of any one or a combination 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 human-made 
factors affecting its continued existence. A species may be 
reclassified or delisted on the same basis.
    A recovered species is one that no longer meets the Act's 
definition of an endangered species or a threatened species. 
Determining whether a species is recovered requires consideration of 
whether the species is endangered or threatened because of the same 
five categories of threats specified in section 4(a)(1) of the Act. For 
species that are already listed as endangered or threatened species, 
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 an ``endangered species'' for purposes of the Act if 
it is in danger of extinction throughout all or a significant portion 
of its range and is a ``threatened species'' if it is likely to become 
an endangered species within the foreseeable future throughout all or a 
significant portion of its range. The Act does not define the term 
``foreseeable future.'' For the purposes of this rule, we define the 
``foreseeable future'' to be the extent to which, given the amount and 
substance of available data, we can anticipate events or effects, or 
reliably extrapolate threat trends, such that we reasonably believe 
that reliable predictions can be made concerning the future as it 
relates to the status of Modoc sucker. Specifically, for Modoc sucker, 
we consider two factors: the management of threats and the response of 
the species to management. First, as described below, the threats to 
the species have been successfully ameliorated, largely due to 
management plans that are currently in place, being fully implemented, 
expected to stay in place, and expected to successfully continue to 
control potential threats (USFS 1989, entire; USFS 1991, entire). 
Management plans that consider natural resources are required by law 
for all Federal lands on which Modoc sucker occurs, which encompass 
greater than 50 percent of the species' range. Management plans are 
required to be in effect at all times and to be in compliance with 
various Federal regulations. Additionally, efforts to promote 
conservation of Modoc sucker habitat on private lands have been 
successful and are expected to continue into the future. Second, the 
Modoc sucker has demonstrated a quick positive response to management 
over the past 28 years since the species was listed; based on this, we 
anticipate being able to detect the species' response to any changes in 
the management that may occur because of a plan amendment. Therefore, 
in consideration of Modoc sucker's positive response to management and 
our partners' commitment to continued management, as we describe below, 
we do not foresee that management practices will change, and we 
anticipate that threats to the Modoc sucker will remain ameliorated 
into the foreseeable future.
    The word ``range'' in the significant portion of its range phrase 
refers to the range in which the species currently exists. For the 
purposes of this analysis, we first evaluate the status of the species 
throughout all its range, then consider whether the species is in 
danger of extinction or likely to become so in any significant portion 
of its range.
    At the time of listing, the primary threats to Modoc sucker were 
from habitat degradation and loss due to activities (such as 
overgrazing by cattle) that cause erosion and siltation, and 
elimination of natural barriers that resulted in loss of genetic 
integrity of the species due to hybridization with Sacramento suckers. 
Predation by the nonnative brown trout was also identified as a threat 
to Modoc sucker.
    A thorough analysis and discussion of the current status of the 
Modoc sucker and stressors faced by the species is detailed in the 
Species Report (Service 2015a, entire). The following sections provide 
a summary of the past, current, and potential future threats impacting 
the Modoc sucker. These threats include activities (such as 
overgrazing) that cause erosion and siltation (Factor A); elimination 
of natural barriers (Factor A); effects of climate change and drought 
(Factor A); predation by nonnative species (Factors C); and 
hybridization and genetic introgression (infiltration of genes of 
another species) (Factor E).

Erosion and Cattle Grazing

    The 1985 listing rule (50 FR 24526; June 11, 1985) stated that 
activities (such as overgrazing) that cause a reduction in riparian 
vegetation, which then leads to stream erosion, siltation, and 
incision, were a threat to the species. An increase in silt from 
eroding banks may fill in the preferred pool habitat of Modoc suckers 
and can cover gravel substrate used for spawning (50 FR 24526, June 11, 
1985; Moyle 2002, p. 190). Sediment introduced into streams can 
adversely affect fish populations by inducing embryo mortality, 
affecting primary productivity, and reducing available habitat for 
macroinvertebrates that Modoc suckers feed upon (Moyle 2002, p. 191). 
However, land and resource management, as guided through regulations 
and policies, can effectively reduce or control threats to Modoc 
sucker.
Federal Management
    The National Forest Management Act (NFMA; 16 U.S.C. 1600 et seq.) 
and regulations and policies implementing the NFMA are the main 
regulatory mechanisms that guide land management on the Fremont-Winema 
and Modoc National Forests, which contain about 51 percent of the Modoc 
sucker's range. Since listing, the Fremont-Winema National Forest (USFS 
1989, entire) and Modoc National Forest (USFS 1991, entire) have each 
addressed the Modoc sucker and its habitat in their resource management 
plans. These plans are required by NFMA and the Federal Land Policy and 
Management Act of 1976 (FLPMA; 43 U.S.C. 1701 et seq.). The NFMA 
requires revision of the plans every 15 years; however, plans may be 
amended or revised as needed. Management plans are required to be in 
effect at all times (in other words, if the revision does not

[[Page 76240]]

occur, the previous plan remains in effect) and to be in compliance 
with various Federal regulations. The plans direct these national 
forests to maintain or increase the status of populations of federally 
endangered or threatened species and their habitats. In addition, these 
plans guide riparian management with a goal of restoring and 
maintaining aquatic and riparian ecosystems to their desired management 
potential (USFS 1989, Appendix p. 86; USFS 1991, pp. 4-26, Appendix pp. 
M-1-M-2).
    Management direction for grazing on Forest-managed lands is 
provided through allotment management plans and permits, which 
stipulate various grazing strategies that will minimize adverse effects 
to the watershed and listed species. The allotment management plans 
outline grazing management goals that dictate rangeland management 
should maintain productive riparian habitat for endangered, threatened, 
and sensitive species (USFS 1995, p. 1). These grazing permits are 
valid for 10 years, but operating instructions for these permits are 
issued on an annual basis. Also, as Federal agencies, the Fremont-
Winema and Modoc National Forests comply with the National 
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.) process when 
evaluating potential land-disturbing projects or changes in National 
Forest management. Federal agency compliance with NEPA allows the 
public to comment on Federal actions that may impact the natural 
environment and thus allow for, in some circumstances, implementation 
of those actions that may have less environmental impact.
State and Private Land Management
    In California, the California Fish and Game Code affords some 
protection to stream habitats for all perennial, intermittent, and 
ephemeral rivers and streams by minimizing impacts. In Oregon, the 
Oregon Department of Land Conservation and Development requires local 
land use planning ordinances to protect natural resources, including 
riparian and wetland habitats. In addition to State protections, 
extensive landowner outreach and improved grazing management practices 
in Modoc and Lassen Counties have also resulted in improved protection 
of riparian corridors on private lands.
    Improved livestock grazing management practices on Federal, State, 
and private lands as a result of Federal, State, and private landowner 
management efforts have greatly reduced impacts to Modoc sucker habitat 
from poor livestock grazing practices since the Modoc sucker's listing 
in 1985. Since listing, some of the Modoc sucker streams on public and 
private land have been fenced to exclude or actively manage livestock 
grazing for the benefit of Modoc sucker conservation (Reid 2008a, pp. 
34-36, 85). Riparian fencing along occupied streams to exclude cattle 
during the past 25 years has resulted in continued improvements in 
riparian vegetative corridors, in-stream cover, and channel morphology.
    In 2012, the most recent habitat assessment, the Klamath Falls Fish 
and Wildlife Office completed habitat surveys in Washington Creek, 
Garden Gulch Creek, Coffee Mill Creek, Dutch Flat Creek, Turner Creek, 
Hulbert Creek, and Johnson Creek within the Ash Creek and Turner Creek 
sub-basins. Data collected indicated that the average percent bank 
erosion was low (less than 40 percent) at Garden Gulch Creek, Coffee 
Mill Creek, Hulbert Creek, Washington Creek, and Johnson Creek. Bank 
erosion appeared moderate at the Dutch Flat Creek site (49 percent) and 
was highest at the Turner Creek site (75 percent). Bank erosion along 
these creeks has resulted in an introduction of silt, which can cover 
gravel substrate used for spawning by Modoc suckers (Moyle 2002, p. 
191). However, these two degraded reaches (Dutch Flat Creek and Turner 
Creek) combined amount to only 4.1 percent (1.76 mi/42.5 mi) of the 
Modoc sucker's total occupied habitat. These results indicate that 
management efforts have substantially reduced erosion throughout the 
range of the species, with the exception of two sites comprising a 
small percentage of the species' range.
    Land management practices employed on public and private lands 
since the early 1980s are expected to continue, or improve, thereby 
maintaining upward habitat trends as documented by survey data. On 
public lands, the resource management plans are required by NFMA and 
FLPMA, and continue to be in effect until revised. Continued commitment 
to protection of resources, including the Modoc sucker and riparian 
areas, in future revisions is expected. As an example, within the 
Fremont-Winema National Forest, Thomas Creek is a Priority Watershed 
under their Watershed Condition Framework, and Fremont-Winema National 
Forest is currently working on a watershed restoration action plan. The 
action plan will identify individual projects such as fish passage, 
instream restoration, and road treatments/closures. The California Fish 
and Game Code affords some protection to stream habitats for all 
perennial, intermittent, and ephemeral rivers and streams in 
California. The Oregon Department of Land Conservation and Development 
requires local land use planning ordinances to protect natural 
resources, including riparian and wetland habitats. There are no 
formalized agreements in place with private landowners that 
specifically establish protection of Modoc sucker habitat, although 
continued outreach and technical assistance, along with other 
partnerships and management efforts, is expected to continue into the 
future (e.g., through the Service's Partners for Fish and Wildlife 
Program) that may result in benefits to Modoc sucker habitat.
    Although the 2012 habitat surveys indicate that livestock grazing 
still results in stream bank erosion along a small percentage of 
streams occupied by Modoc suckers, these surveys and the 2008 and 2012 
fish surveys indicate that livestock grazing management has improved 
greatly, and as a result of reduced impact to habitat, there has been 
no reduction in the distribution of Modoc suckers. Management plans 
that consider natural resources are required by law for all Federal 
lands on which Modoc sucker occurs. Management plans are required to be 
in effect at all times (in other words, if the revision does not occur, 
the previous plan remains in effect) and to be in compliance with 
various Federal regulations. Further, several organizations have 
partnered with private landowners to complete habitat restoration on 
the private land parcels to benefit fish passage and riparian habitat. 
Therefore, based on the best available information and expectation that 
current management practices will continue into the future, we conclude 
that livestock grazing and erosion do not constitute substantial 
threats to the Modoc sucker now and are not expected to in the future.

Elimination of Natural Barriers

    The 1985 listing rule (50 FR 24526; June 11, 1985) stated that 
natural passage barriers in streams occupied by Modoc suckers had been 
eliminated by human activities, allowing hybridization between the 
Modoc and Sacramento suckers (see Hybridization and Genetic 
Introgression, below). The lack of barriers was also thought to provide 
exposure to nonnative predatory fishes (see Predation by Nonnative 
Species, below). However, surveys completed since the time of listing 
reveal no evidence of historical natural barriers that would have acted 
as a physical barriers to fish movement. This is particularly true 
during higher springtime flows, when Sacramento

[[Page 76241]]

suckers make their upstream spawning migrations (Moyle 2002, p. 187). 
The source of this misunderstanding appears to have been a purely 
conjectural discussion by Moyle and Marciochi (1975, p. 559) that was 
subsequently accepted without validation, and Moyle makes no mention of 
it in his most recent account of Modoc sucker status (Moyle 2002, pp. 
190-191). Since our current understanding is that the elimination of 
passage barriers did not occur, we conclude that elimination of passage 
barriers was incorrectly identified as a threat, and we no longer 
consider it a threat to Modoc sucker.

Predation by Nonnative Species

    The 1985 listing rule (50 FR 24526; June 11, 1985) identified 
predation by nonnative brown trout as a threat to Modoc suckers. Since 
the time of listing, the following additional predatory nonnative fish 
species have been recorded in streams containing Modoc suckers (Service 
2009): largemouth bass, sunfish (green and bluegill), and brown 
bullheads. Two of the three known sub-basins with Modoc suckers contain 
introduced predatory fishes. The Ash Creek sub-basin contains brown 
trout and possibly largemouth bass in downstream reaches of Ash Creek. 
The Turner Creek sub-basin contains a number of warm-water predatory 
fish. The Goose Lake sub-basin was previously stocked with brook trout 
(Salvelinus fontinalis), and they still occur in the Cottonwood Creek 
drainage, a tributary to Goose Lake. However, we do not consider the 
brook trout to be a concern at this time, as they do not coexist with 
Modoc sucker.
    The Ash Creek sub-basin contains brown trout, which have co-existed 
with Modoc suckers for over 70 years, but may suppress local native 
fish populations in small streams. In 2009 and 2010, a substantial 
eradication effort in Johnson Creek, within the Ash Creek sub-basin, 
removed most brown trout from occupied Modoc sucker habitat (Reid 2010, 
p. 2). There are no sources of largemouth bass upstream of Modoc sucker 
populations in the Ash Creek basin, although they may be present 
downstream in warmer, low-gradient reaches of Ash Creek proper.
    The Turner Creek sub-basin contains largemouth bass, sunfish (green 
and bluegill), and brown bullheads, of which only the bass are 
considered a significant predator on Modoc suckers. Bass do not appear 
to reproduce or establish stable populations in Turner Creek because 
the creek's cool-water habitat is generally unsuitable for supporting 
largemouth bass populations. Since 2005, the Service has supported a 
successful program of active management for nonnative fishes in the 
Turner Creek basin, targeting bass and sunfishes with selective angling 
and hand-removal methods that do not adversely impact native fish 
populations (Reid 2008b, p. 1).
    Redband trout (Oncorhynchus mykiss newberri), the only native 
potential predator of Modoc sucker, also occupies upper Thomas Creek, 
but there are no nonnative fishes there (Scheerer et al. 2010, pp. 278, 
281). The upper reaches of Thomas Creek occupied by Modoc suckers are 
unlikely to be invaded by nonnative fishes given the lack of upstream 
source populations and presence of a natural waterfall barrier in the 
lowest reach.
    While Modoc suckers may be negatively impacted by introduced 
predatory fishes, such as brown trout and largemouth bass, they have 
persisted in the presence of nonnative predators, and populations have 
remained relatively stable in the Ash Creek and Turner Creek sub-basins 
(the two sub-basins with documented nonnative predatory fish), prior to 
and since the time of listing. The separation of the three known basins 
containing Modoc suckers further reduces the probability that a new or 
existing nonnative predator would impact all three basins 
simultaneously. In some instances, natural constraints, such as cool-
water habitat, limit the distribution of nonnative predators. In other 
cases, natural or manmade barriers limit potential introductions, as do 
policies and regulations within Oregon and California. State 
regulations and fish stocking policies, in both California and Oregon, 
prohibit transfer of fish from one water body to another. Regulations 
prohibiting transfer of fish between water bodies discourage the spread 
of predatory fish species such as brown trout and largemouth bass 
throughout the Modoc sucker's range. In addition, CDFW has discontinued 
stocking of the predatory brown trout into streams in the Pit River 
basin, and the ODFW does not stock brown trout in the Goose Lake sub-
basin. Based on current policies and regulations, we do not expect 
additional predatory fish to be introduced into Modoc sucker habitat in 
the future. Therefore, based on the best available information, we 
conclude that introduced predators do not constitute a substantial 
threat to the Modoc sucker now or in the future.

Climate Change and Drought

    Our analyses under the Act include consideration of ongoing and 
projected changes in climate. The terms ``climate'' and ``climate 
change'' are defined by the Intergovernmental Panel on Climate Change 
(IPCC). The term ``climate'' refers to the mean and variability of 
different types of weather conditions over time, with 30 years being a 
typical period for such measurements (IPCC 2013, p. 1450). The term 
``climate change'' thus refers to a change in the mean or variability 
of one or more measures of climate (for example, temperature or 
precipitation) that persists for an extended period, whether the change 
is due to natural variability or human activity (IPCC 2013, p. 1450). 
Various changes in climate may have direct or indirect effects on 
species. These effects may be positive, neutral, or negative, and they 
may change over time, depending on the species and other relevant 
considerations, such as threats in combination and interactions of 
climate with other variables (for example, habitat fragmentation) (IPCC 
2014, pp. 4-11). In our analyses, we use our expert judgment to weigh 
relevant information, including uncertainty, in our consideration of 
various aspects of climate change.
    The 1985 listing rule did not identify the effects of drought or 
climate change as threats to the continued existence of the Modoc 
sucker. However, the northwestern corner of the Great Basin is 
naturally subject to extended droughts, during which streams and even 
the larger water bodies such as Goose Lake have dried up (Laird 1971, 
pp. 57-58). Regional droughts have occurred every 10 to 20 years in the 
last century, and Goose Lake went dry as recently as 1992 and 2010 
(Reid 2008a, pp. 43-44; R. Larson, KFFWO, personal communication). We 
have no records of how frequently Modoc sucker streams went dry. Some 
reaches of occupied streams have been observed to dry up (or flow goes 
subsurface through the gravel instead of over the surface) nearly every 
summer under current climatic conditions (Reid 2008, p. 42), indicating 
that headwater reaches did stop flowing. In extreme droughts, the 
suckers may have withdrawn to permanent main-stem streams, such as 
Rush, Ash, and Turner Creeks, and later recolonized the tributaries. 
Suckers also take refuge in natural spring-fed headwater reaches and in 
deeper, headwater pools that receive subsurface flow even when most of 
the stream channel is dry (Reid 2008, p. 43). Collections of Modoc 
suckers from Rush Creek and Thomas Creek near the end of the 
``dustbowl'' drought (Hubbs 1934, p. 1; Reid 2008a, p. 79) and the 
continued persistence of Modoc suckers throughout their known range 
through substantial local drought years since 1985, including up to the 
present,

[[Page 76242]]

demonstrate the resiliency of Modoc sucker populations to drought.
    Human-induced climate change could exacerbate low-flow conditions 
in Modoc sucker habitat during future droughts. A warming trend in the 
mountains of western North America is expected to decrease snowpack, 
hasten spring runoff, reduce summer stream flows, and increase summer 
water temperatures (Poff et al. 2002, p. 11; Koopman et al. 2009, p. 3; 
PRBO Conservation Science 2011, p. 15). Lower flows as a result of 
smaller snowpack could reduce sucker habitat, which might adversely 
affect Modoc sucker reproduction and survival. Warmer water 
temperatures could lead to physiological stress and could also benefit 
nonnative fishes that prey on or compete with Modoc suckers. Increases 
in the number and size of forest fires could also result from climate 
change (Westerling et al. 2006, p. 940) and could adversely affect 
watershed function resulting in faster runoff, lower base flows during 
the summer and fall, and increased sedimentation rates. It is possible 
that lower flows may result in increased groundwater withdrawal for 
agricultural purposes and thus reduced water availability in certain 
stream reaches occupied by Modoc suckers. While these are all possible 
scenarios, we have no data on which to predict the likelihood or 
magnitude of these outcomes. However, improved habitat conditions may 
also offset some of the potential effects of climate change. Increased 
riparian vegetation, increased instream cover, and improved channel 
morphology (including deeper pools) may help to moderate water 
temperatures, reduce erosion and sedimentation, and improve water 
retention for refugia during droughts.
    In summary, droughts may be a concern because they could likely 
constrict the amount of available habitat and reduce access to spawning 
habitat. However, the species has not declined in distribution since 
the time of listing in 1985, even though during this time the region 
where the species exists has experienced several pronounced droughts 
when total annual precipitation was approximately half of the long-term 
average (Western Regional Climate Center, https://www.wrcc.dri.edu/cgi-bin/cliMONtpre.pl?ca0161, accessed December 20, 2013). Because we are 
unable at this time to predict how climate change may exacerbate the 
effects of drought within the Modoc sucker's range, we cannot make 
meaningful projections on how the species may react to climate change 
or how its habitat may be affected. Also, although we cannot predict 
future climatic conditions accurately, the persistence of Modoc sucker 
across its range through the substantial droughts of the last century 
suggests that the species is resilient to drought and reduced water 
availability. In addition, improved habitat conditions may increase the 
resiliency of both the Modoc sucker and its habitat to the effects of 
climate change. Therefore, based on the best available information, we 
conclude that the effects of droughts and climate change, while likely 
affecting Modoc sucker populations, do not constitute substantial 
threats to Modoc sucker now and are not expected to in the future.

Hybridization and Genetic Introgression

    The 1985 listing rule (50 FR 24526; June 11, 1985) identified 
hybridization with the Sacramento sucker as a threat to the Modoc 
sucker. Hybridization can be cause for concern in a species with 
restricted distribution, particularly when a closely related, nonnative 
species is introduced into its range, which can lead to loss of genetic 
integrity or even extinction (Rhymer and Simberloff 1996, p. 83). At 
the time of listing, it was assumed that hybridization between Modoc 
suckers and Sacramento suckers had been prevented in the past by the 
presence of natural physical barriers, but that the loss of these 
stream barriers was allowing interaction and hybridization between the 
two species (see Elimination of Natural Barriers, above). However, the 
assumption that extensive hybridization was occurring was based solely 
on the two species occurring in the same streams, and the 
identification of a few specimens exhibiting what were thought to be 
intermediate morphological characters. At the time of listing in 1985, 
genetic and complete morphological information to assess this 
assumption were not available.
    The morphological evidence for hybridization in the 1985 listing 
rule was based on a limited understanding of morphological variation in 
Modoc suckers and Sacramento suckers, derived from the small number of 
specimens available at that time. The actual number of specimens 
identified as apparent hybrids by earlier authors was very small, and 
many of these specimens came from streams without established Modoc 
sucker populations. Subsequent evaluation of variability in the two 
species was based on a larger number of specimens. It showed that the 
overlapping characteristics (primarily lateral line and dorsal ray 
counts) that had been interpreted by earlier authors as evidence of 
hybridization are actually part of the natural meristic (involving 
counts of body parts such as fins and scales) range for the two 
species. As a result, this variability is no longer thought to be the 
result of genetic introgression between the two species (Kettratad 
2001, pp. 52-53).
    In 1999, we initiated a study to examine the genetics of suckers in 
the Pit River basin and determine the extent and role of hybridization 
between the Modoc and Sacramento suckers using both nuclear and 
mitochondrial genes (Palmerston et al. 2001, p. 2; Wagman and Markle 
2000, p. 2; Dowling 2005, p. 3; Topinka 2006, p. 50). The two species 
are genetically similar, suggesting that they are relatively recently 
differentiated or have a history of introgression throughout their 
ranges that has obscured their differences (Dowling 2005, p. 9; Topinka 
2006, p. 65). Although the available evidence cannot differentiate 
between the two hypotheses, the genetic similarity in all three sub-
basins, including those populations shown to be free of introgression 
based on species-specific genetic markers (Topinka 2006, pp. 64-65), 
suggests that introgression has occurred on a broad temporal and 
geographic scale and is not a localized or recent phenomenon. 
Consequently, the genetic data suggest that introgression is natural 
and is not caused or measurably affected by human activities.
    In a later study, Topinka (2006, p. 50) analyzed nuclear DNA from 
each of the two species and identified species-specific markers 
indicating low levels of introgression by Sacramento sucker alleles 
into most Modoc sucker populations. However, there was no evidence of 
first generation hybrids, and it is not clear whether introgression 
occurred due to local hybridization or through immigration by 
individual Modoc suckers carrying Sacramento alleles from other areas 
where hybridization had occurred.
    Scientists who have studied suckers in western North America 
consider that, throughout their evolutionary history, hybridization 
among sympatric native fishes is not unusual and may provide an 
adaptive advantage (Dowling and Secor 1997, pp. 612-613; Dowling 2005, 
p. 10; Topinka 2006, p. 73; Tranah and May 2006, p. 313). Further, 
despite any hybridization that has occurred in the past, the Modoc 
sucker maintains its morphological and ecological distinctiveness, even 
in populations showing low levels of introgression, and is clearly 
distinguishable in its morphological characteristics from the 
Sacramento sucker (Kettratad 2001, p. 3; Smith et al. 2011, pp. 79-83). 
The low levels of observed introgression by

[[Page 76243]]

Sacramento suckers in streams dominated by Modoc suckers, even when 
there are no physical barriers between the two species, suggests that 
ecological differences, selective pressures, or other natural 
reproductive-isolating mechanisms are sufficient to maintain the 
integrity of the species, even after more than a century of habitat 
alteration by human activities. Therefore, given the low levels of 
observed introgression in streams dominated by Modoc suckers, the lack 
of evidence of first-generation hybrids, the fact that Modoc suckers 
and Sacramento suckers are naturally sympatric, and the continued 
ecological and morphological integrity of Modoc sucker populations, we 
conclude that hybridization and genetic introgression do not constitute 
threats to the Modoc sucker now and are not expected to in the future.

Overall Summary of Factors Affecting the Modoc Sucker

    Threats to the Modoc sucker that were considered in the 1985 
listing rule (50 FR 24526; June 11, 1985) included habitat loss and 
degradation, hybridization with Sacramento sucker due to loss of 
natural barriers, and predation by nonnative brown trout. Climate 
change, drought, and predation by additional nonnative fish species are 
threats identified since listing. We summarize our evaluation of these 
threats below.
    In our evaluation of the threat of habitat loss and degradation as 
a result of land management practices, we find that habitat conditions 
on both public and private lands have improved since the time of 
listing as a result of improved livestock grazing management practices 
and construction of fencing to exclude cattle from riparian areas on 
several of the streams occupied by Modoc suckers. We expect habitat 
conditions to remain stable or improve. Although recent habitat surveys 
indicate erosion continues to be a problem along lower Turner Creek and 
in Dutch Flat Creek, these areas represent only 4.1 percent (1.76 mi/
42.5 mi) of Modoc sucker's total occupied habitat. Habitat threats are 
addressed through multiple Federal and State regulations, including 
NFMA, California and Oregon State water regulations, and the California 
Fish and Game Code. Therefore, these impacts are not considered a 
substantial threat to the species.
    We also evaluated whether several introduced nonnative fish species 
that could be potential predators may be a threat to Modoc suckers. 
Modoc suckers have coexisted with brown trout for more than 70 years in 
the Ash Creek sub-basin. For other species, we found that the overlap 
in distribution of largemouth bass and Modoc suckers is limited because 
bass are warm-water fish that occur in lower elevation reaches 
downstream of many of the reaches occupied by Modoc sucker, and 
reservoir outflows have been screened to reduce the risk of bass being 
flushed into streams occupied by Modoc sucker. Brook trout occur in a 
tributary of the Goose Lake sub-basin but do not overlap with the range 
of the species. Further, State regulations in both California and 
Oregon prohibit transfer of fish from one water body to another. Thus, 
introduced predators are not a significant risk to Modoc sucker 
populations.
    We also evaluated new information regarding hybridization of Modoc 
sucker with Sacramento sucker. As discussed above, a greater 
understanding of the genetic relationships and natural gene flow 
between the Modoc sucker and Sacramento sucker has reduced concerns 
over hybridization between the two naturally sympatric species.
    Threats to the Modoc sucker that were considered in the 1985 
listing rule, including habitat loss and degradation, hybridization 
with Sacramento sucker due to loss of natural barriers, and predation 
by nonnative brown trout, have been reduced or ameliorated, or are no 
longer considered to have been actual threats at the time of listing. 
Further, climate change and drought and are not considered substantial 
threats.
    Although none of the factors discussed above is having a major 
impact on Modoc sucker, a combination of factors could potentially have 
a greater effect. For example, effects of erosion on habitat resulting 
from poor livestock grazing management practices could worsen during 
periods of prolonged, severe drought when some water sources may dry 
up, resulting in greater pressure from cattle on the remaining 
available water sources, which would likely degrade Modoc sucker 
habitat. However, the impacts of livestock grazing on Modoc sucker 
habitat have been greatly reduced or eliminated by improved grazing 
management practices and management plans, which are not expected to 
change. Although the types, magnitude, or extent of cumulative impacts 
are difficult to predict, we are not aware of any combination of 
factors that has not already been addressed, or would not be addressed, 
through ongoing conservation measures. Based on this assessment of 
factors potentially impacting the species, we consider the Modoc sucker 
to have no substantial threats now or in the future (see ``Summary of 
Factors Affecting the Species'' section of the Species Report (Service 
2015a, pp. 14-30).

Summary of Comments and Recommendations

    In the proposed rule published on February 13, 2014 (79 FR 8656), 
and in the document reopening the comment period published on February 
13, 2015 (80 FR 8053), in the Federal Register, we requested that all 
interested parties submit written comments on the proposal by April 14, 
2014, and March 16, 2015, respectively. We also contacted appropriate 
Federal and State agencies, Tribal entities, scientific experts and 
organizations, and other interested parties and invited them to comment 
on the proposal. A newspaper notice inviting general public comment was 
published in the Herald and News of Klamath Falls, Oregon. We did not 
receive any requests for a public hearing. All substantive information 
provided during comment periods has either been incorporated directly 
into this final determination or is addressed below.

Peer Reviewer Comments

    In accordance with our peer review policy published on July 1, 1994 
(59 FR 34270), we solicited expert opinion from three knowledgeable 
individuals with scientific expertise that included familiarity with 
the Modoc sucker and its habitat, biological needs, and threats. We 
received responses from all three of the peer reviewers.
    We reviewed all comments we received from the peer reviewers for 
substantive issues and new information regarding the status of the 
Modoc sucker. The peer reviewers generally concurred with our methods 
and conclusions, and provided additional information, clarifications, 
and suggestions to improve the final rule. This information has been 
incorporated into the final rule or species report as appropriate. The 
peer reviewer comments are addressed in the following summary.

Comments From Peer Reviewers

    (1) Comment: One peer reviewer noted the status of the Modoc sucker 
in Dutch Flat Creek (California) was not addressed adequately within 
the Recovery and Recovery Plan Implementation section of the proposed 
rule and provided additional information. In the downlisting and 
delisting objectives that were listed under the Recovery and Recovery 
Plan Implementation section of the proposed rule, the peer reviewer 
indicated that

[[Page 76244]]

Dutch Flat Creek should be added to the text in several of the 
discussions of recovery objectives.
    Our Response: We did not specifically include Dutch Flat Creek in 
our discussions of how each objective had been met because the 
objectives as written did not specifically include Dutch Flat Creek. 
While the proposed and final rules contain only a general summary 
discussion, our overall assessment of the species status and its 
progress toward recovery considered all streams occupied by the Modoc 
sucker, including those previously not known to be occupied. The 
Species Report includes Dutch Flat Creek in its assessment and contains 
numerous references to the status of Modoc suckers and their habitat in 
Dutch Flat Creek.
    (2) Comment: One peer reviewer provided additional citations within 
the Summary of Factors Affecting Species section for amendments to the 
Forest Plans of the Fremont-Winema and Modoc National Forests. Both 
amendments provided habitat conservation measures within riparian 
areas, primarily by prescribing riparian conservation area widths.
    Our Response: We appreciate the reviewer providing additional 
citations further supporting that the threats to the species have been 
successfully ameliorated. We incorporated this information into the 
revised Species Report (Service 2015a).
    (3) Comment: One peer reviewer provided an additional reference 
that included additional information related to nonnative fish removal 
in the Turner Creek sub-basin.
    Our Response: We appreciate the reviewer providing a citation with 
additional background information on nonnative fish removal from the 
Turner Creek sub-basin. We incorporated this information into the 
revised Species Report (Service 2015a).
    (4) Comment: One peer reviewer noted that the statement that Modoc 
suckers are present in only 3.4 mi (5.5 km) of available habitat 
Washington Creek, citing Reid 2008a (Conservation Review), is somewhat 
inaccurate. It is true that they were encountered in only 3.4 mi (5.5 
km) during surveys carried out in July 2008, when higher reaches were 
naturally dry; however, as mentioned in the same survey report, young 
of the year (indicative of local spawning) have been found (2006) as 
far upstream as near Loveness Road, the upper limit of potential 
habitat, earlier in the year when the stream channel still has water, 
indicating that Modoc suckers are actually using the entire reach.
    Our Response: The Service has noted this comment and made 
corrections to the Species Report to reflect this clarification.
    (5) Comment: Recent Oregon survey data by USFS (2013) were not 
included in the draft Species Report (Service 2013).
    Our Response: We did not include data from 2013 in the draft 
Species Report (Service 2013) or proposed rule due to the required 
timelines involved with preparation of the proposed rule. The 
information did not change the distribution, but reaffirmed the 
presence of the Modoc sucker in upper Thomas Creek, above Cox Flat. We 
reviewed these data and determined that they indicate no change in the 
status of the species from information provided in the proposed rule. 
We included the information in the revised Species Report (Service 
2015a).
    (6) Comment: One peer reviewer stated that the proposed rule 
suggests that continued grazing is causing erosion on Turner Creek and 
represents an adverse effect on sucker populations and that there no 
scientific evidence provided to support this conclusion. This reach has 
steadily improved in condition over the last 15 years under current 
management. The down-cutting observed in the meadow is apparently a 
legacy effect from a major storm in the 1940s and 1950s, and the creek 
is slowly healing in a steady upward trend, albeit less rapidly than it 
would without grazing. The reviewer also noted extreme downcutting in 
Dutch Flat is also a legacy effect (of ditching to dry out the meadow), 
but that erosion does still occur at failed points in the cattle 
fencing.
    Our Response: We agree with the peer reviewer that erosion due to 
grazing effects on Modoc sucker habitat is generally a legacy effect 
from historic grazing practices. The Service has noted this comment and 
made corrections to the Species Report to reflect this clarification.
    (7) Comment: An additional reference (Smith et al. 2011, pp. 72-84) 
was provided to support the conclusion under Factor E that 
hybridization between Modoc and Sacramento suckers is not a threat.
    Our Response: We appreciate the reviewer providing a citation that 
further supports that hybridization between the Modoc sucker and the 
Sacramento sucker is not a threat to the Modoc sucker. We have 
incorporated this reference into the Species Report and this final 
rule.

Comments From Federal Agencies

    (8) Comment: The USFS (Fremont-Winema National Forest) noted that 
the ``dustbowl'' drought was more than 80 years ago and the Goose Lake 
basin has changed since that time. There is more pressure on fish 
habitat now than there was 80 years ago, so we cannot assume that the 
effects of drought conditions are the same now as they were back then.
    Our Response: The northwestern corner of the Great Basin is 
naturally subject to extended droughts, during which streams and even 
the larger water bodies such as Goose Lake have dried up. The Service 
agrees droughts may be a concern because they could likely constrict 
the amount of available habitat and reduce access to spawning habitat. 
However, the species has not declined in distribution since the time of 
listing in 1985, even though the region where it exists has experienced 
several pronounced droughts (when total annual precipitation was 
approximately half of the long-term average) since then. Although the 
Service cannot predict future climatic conditions with certainty, the 
persistence of the Modoc sucker across its range through the 
substantial droughts of the last century suggests that the species is 
resilient to drought and reduced water availability. Additionally, 
while there is some uncertainty regarding how the Modoc sucker may 
respond to future droughts, continued monitoring and management through 
the post-delisting monitoring plan (Service 2015b) are designed to 
detect any unanticipated changes in the species' status and habitat 
conditions. We also expect continued monitoring and management through 
implementation of Federal and State management plans and through 
riparian restoration and management efforts on private lands.
    (9) Comment: The USFS noted an incorrect citation for their 
management plan that has successfully ameliorated threats to the Modoc 
sucker for the Fremont-Winema National Forest. The correct citation for 
the Fremont National Forest Land and Resource Management Plan should 
be: U.S Forest Service. 1989. Land and Resource Management Plan.
    Our Response: The Service has noted this correction and has updated 
the references cited document supporting this rule to reflect the 
change.
    (10) Comment: The Fremont-Winema National Forest noted the most 
significant USFS regulatory mechanism to successfully ameliorate 
threats to the Modoc sucker was the Inland Native Fish Strategy 
(InFish) amendment to the Fremont National Forest Land and

[[Page 76245]]

Resource Management Plan. InFish was developed as an ecosystem-based, 
interim strategy designed to arrest the degradation of habitat and 
begin restoration of in-stream and riparian habitats on lands 
administered by the USFS in eastern Oregon.
    Our Response: The Service has noted this comment and made changes 
to the Species Report to reflect this additional information.
    (11) Comment: The Fremont-Winema National Forest noted that in the 
Erosion and Cattle Grazing discussion in the Summary of Factors 
Affecting the Species section in the proposed rule (79 FR 8656; 
February 13, 2014), the Service failed to mention work completed and 
proposed by the Lake County Umbrella Watershed Council to improve fish 
habitat throughout the Goose Lake sub-basin, including upper and lower 
Thomas Creek, and the historic work done by the Goose Lake fishes 
working group.
    Our Response: We recognize that land management practices employed 
on public and private lands by a diverse group of entities are expected 
to continue, or improve, thereby maintaining upward instream and 
riparian habitat trends. We noted efforts of the Fremont-Winema 
National Forest to restore habitat as one example in the proposed rule. 
We now also acknowledge and include reference to such groups in the 
revised Species Report, to recognize that many groups (including 
private landowners and State agencies) have, and are continuing, to 
complete restoration for the benefit of Modoc sucker and other native 
fishes.
    (12) Comment: The Fremont-Winema National Forest indicated in the 
Predation by Nonnative Species discussion in the Summary of Factors 
Affecting the Species section in the proposed rule (79 FR 8656; 
February 13, 2014) that what was described as a natural waterfall 
barrier at the downstream end of Modoc sucker distribution in Thomas 
Creek may be navigable by brook trout (Salvelinus fontinalis), and 
therefore Thomas Creek is susceptible to invasion of nonnative species 
that could prey on Modoc suckers.
    Our Response: The Service has determined that the natural waterfall 
is likely a barrier to upstream movement by nonnative species, such as 
brook trout, as surveys since at least 2007 have not documented 
nonnative species upstream from the waterfall. Further, Sheerer et al. 
(2010) indicate no brook trout occur downstream of habitat occupied by 
Modoc sucker in Thomas Creek.
    (13) Comment: The Fremont-Winema National Forest noted that brook 
trout had been stocked in the Goose Lake basin in the past and they 
still occur in the Cottonwood Creek drainage, a tributary to Goose 
Lake.
    Our Response: The Service has noted this comment and made reference 
to this in the revised Species Report.
    (14) Comment: In the Climate Change and Drought discussion of the 
Summary of Factors Affecting the Species section of the proposed rule, 
the Fremont-Winema National Forest noted there is a lack of data to 
support future impacts of climate change on the Modoc sucker, 
particularly without a baseline level of monitoring.
    Our Response: As stated in the proposed rule (79 FR 8656; February 
13, 2014), we cannot predict future climatic conditions with certainty 
or their effects on the Modoc sucker, but the persistence of the Modoc 
sucker across its range through the substantial droughts of the last 
century suggests that the species is resilient to drought and reduced 
water availability. Because we are unable at this time to predict how 
climate change will exacerbate the effects of drought within the Modoc 
sucker's range, we cannot make meaningful projections on how the 
species may react to climate change or how its habitat may be affected. 
However, we believe continued monitoring and management can detect any 
unanticipated changes in the species' status and habitat conditions.

Comments From Tribes

    (15) Comment: The Pit River Tribe opposes the delisting of Modoc 
sucker because the delisting would allow the Pit River to continue to 
be degraded and polluted.
    Our Response: The Modoc sucker occupies habitat in the Turner Creek 
and Ash Creek sub-basins in northeastern California, which are 
tributaries of the Pit River. However, the Modoc sucker does not occupy 
the mainstem Pit River. Therefore, delisting the Modoc sucker will not 
change activities in the Pit River. Moreover, we do not have direct 
regulatory authority over the water management within the Pit River. 
However, the California Fish and Game Code affords some protection to 
stream habitats for all perennial, intermittent, and ephemeral rivers 
and streams. Under the California Fish and Game Code, any person, State 
or local governmental agency, or public utility must notify CDFW prior 
to conducting activities that would divert or obstruct stream flow, use 
or alter streambed and stream bank materials, or dispose of debris that 
may enter streams (California Fish and Game Code section 1602). This 
section of the California Fish and Game Code provides some level of 
protection to the mainstem Pit River.

Comments From States

    (16) Comment: Both the CDFW and ODFW responded in support of the 
proposed delisting of Modoc sucker.
    Our Response: We appreciate the review and feedback provided by 
both State agencies.

Public Comments

    (17) Comment: Three commenters were opposed to the delisting of the 
Modoc sucker, in part due to the perceived threat from drought.
    Our Response: At the time of listing in 1985, the Service, CDFG, 
and USFS were in the process of developing an action plan for the 
recovery of the Modoc sucker. In 1992, the Service adopted this action 
plan as the recovery plan for the Modoc sucker. Three downlisting 
objectives and three delisting objectives were identified in the 1992 
Recovery Plan, which included a delisting objective related to drought. 
Because we are unable at this time to predict to what extent climate 
change will exacerbate the effects of drought within the Modoc sucker's 
range, we cannot make meaningful projections on how the species may 
react to climate change or how its habitat may be affected. However, 
Modoc suckers have persisted throughout the species' historical range 
since the time the species was listed in 1985, even though the region 
has experienced several pronounced droughts, indicating that the 
species is at least somewhat resilient to weather and hydrologic 
fluctuations. Therefore, we have determined that this delisting 
objective has been met and that the best available information does not 
indicate that the current level of drought is a threat to the species.

Determination

    An assessment of the need for a species' protection under the Act 
is based on whether a species is in danger of extinction or likely to 
become so because of any of five factors: (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. As required by section 4(a)(1) of 
the Act, we conducted a review of the status of this species and 
assessed the five factors to evaluate whether the Modoc sucker is

[[Page 76246]]

in danger of extinction, or likely to become so throughout all of its 
range. We examined the best scientific and commercial information 
available regarding the past, present, and future threats faced by the 
species. We reviewed information presented in the 2011 petition, 
information available in our files and gathered through our 90-day 
finding in response to this petition, and other available published and 
unpublished information. We also consulted with species experts and 
land management staff with the USFS, CDFW, and ODFW, who are actively 
managing for the conservation of the Modoc sucker.
    In considering what factors might constitute threats, we must look 
beyond the mere exposure of the species to the factor to determine 
whether the exposure 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 the threat is. If the threat is significant, 
it may drive, or contribute to, the risk of extinction of the species 
such that the species warrants listing as endangered or threatened as 
those terms are defined by the Act. This determination 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 is not sufficient to compel a finding that 
listing is appropriate; we require evidence that these factors are 
operative threats that act on the species to the point that the species 
meets the definition of an endangered species or threatened species 
under the Act.
    Significant impacts at the time of listing (50 FR 24526; June 11, 
1985) that could have resulted in the extirpation of all or parts of 
populations have been eliminated or reduced since listing. We conclude 
that the previously recognized impacts to Modoc sucker from the present 
or threatened destruction, modification, or curtailment of its habitat 
or range (specifically, erosion due to poor cattle grazing management) 
(Factor A); elimination of natural barriers (Factor A); predation by 
nonnative species (Factor C); hybridization or genetic introgression 
(specifically, from Sacramento sucker) (Factor E); and the effects of 
drought and climate change (Factor E) do not rise to a level of 
significance, such that the species is in danger of extinction 
throughout all its range now or in the foreseeable future.
    As a result of the discovery of five populations not known at the 
time of listing and the documentation of the genetic integrity of 
populations considered in the 1985 listing rule that were believed to 
have been lost due to hybridization, the known range of the Modoc 
sucker has increased, and it currently occupies its entire known 
historical range. Additionally, the distribution of occupied stream 
habitat for populations known at the time of listing has remained 
stable or expanded slightly since the time of listing, even though the 
region has experienced several droughts during this time period. 
Additionally, the relevant recovery objectives outlined in the 1992 
Recovery Plan have been met, indicating sustainable populations exist 
throughout the species' range. Finally, our assessment of all potential 
stressors that may be impacting the species now or in the future did 
not reveal any significant threats to the species or its habitat. We 
have carefully assessed the best scientific and commercial data 
available and determined that Modoc sucker is no longer in danger of 
extinction throughout all of its range, nor is it likely to become so 
in the future.

Significant Portion of the Range

    Having examined the status of Modoc sucker throughout all its 
range, we next examine whether the species is in danger of extinction, 
or likely to become so, in a significant portion of its range. Under 
the Act and our implementing regulations, a species may warrant listing 
if it is in danger of extinction or likely to become so throughout all 
or a significant portion of its range. The Act defines ``endangered 
species'' as any species which is ``in danger of extinction throughout 
all or a significant portion of its range,'' and ``threatened species'' 
as any species which is ``likely to become an endangered species within 
the foreseeable future throughout all or a significant portion of its 
range.'' The term ``species'' includes ``any subspecies of fish or 
wildlife or plants, and any distinct population segment [DPS] of any 
species of vertebrate fish or wildlife which interbreeds when mature.'' 
We published a final policy interpreting the phrase ``significant 
portion of its range'' (SPR) (79 FR 37578; July 1, 2014). The final 
policy states that (1) if a species is found to be endangered or 
threatened throughout a significant portion of its range, the entire 
species is listed as an endangered species or a threatened species, 
respectively, and the Act's protections apply to all individuals of the 
species wherever found; (2) a portion of the range of a species is 
``significant'' if the species is not currently endangered or 
threatened throughout all of its range, but the portion's contribution 
to the viability of the species is so important that, without the 
members in that portion, the species would be in danger of extinction, 
or likely to become so in the foreseeable future, throughout all of its 
range; (3) the range of a species is considered to be the general 
geographical area within which that species can be found at the time 
the Service or the National Marine Fisheries Service (NMFS) makes any 
particular status determination; and (4) if a vertebrate species is 
endangered or threatened throughout an SPR, and the population in that 
significant portion is a valid DPS, we will list the DPS rather than 
the entire taxonomic species or subspecies.
    The SPR policy is applied to all status determinations, including 
analyses for the purposes of making listing, delisting, and 
reclassification determinations. The procedure for analyzing whether 
any portion is an SPR is similar, regardless of the type of status 
determination we are making. The first step in our analysis of the 
status of a species is to determine its status throughout all of its 
range. If we determine that the species is in danger of extinction, or 
likely to become so in the foreseeable future, throughout all of its 
range, we list the species as an endangered (or threatened) species and 
no SPR analysis will be required. If the species is neither in danger 
of extinction, nor likely to become so, throughout all of its range, we 
determine whether the species is in danger of extinction or likely to 
become so throughout a significant portion of its range. If it is, we 
list the species as an endangered species or a threatened species, 
respectively; if it is not, we conclude that listing the species is not 
warranted.
    When we conduct an SPR analysis, we first identify any portions of 
the species' range that warrant further consideration. The range of a 
species can theoretically be divided into portions in an infinite 
number of ways. However, there is no purpose to analyzing portions of 
the range that are not reasonably likely to be significant and 
endangered or threatened. To identify only those portions that warrant 
further consideration, we determine whether there is substantial 
information indicating that (1) the portions may be significant and (2) 
the species may be in danger of extinction in those portions or likely 
to become so within the

[[Page 76247]]

foreseeable future. We emphasize that answering these questions in the 
affirmative is not a determination that the species is endangered or 
threatened throughout a significant portion of its range--rather, it is 
a step in determining whether a more detailed analysis of the issue is 
required. In practice, a key part of this analysis is whether the 
threats are geographically concentrated in some way. If the threats to 
the species are affecting it uniformly throughout its range, no portion 
is likely to warrant further consideration. Moreover, if any 
concentration of threats apply only to portions of the range that 
clearly do not meet the biologically based definition of 
``significant'' (i.e., the loss of that portion clearly would not be 
expected to increase the vulnerability to extinction of the entire 
species), those portions will not warrant further consideration.
    If we identify any portions that may be both (1) significant and 
(2) endangered or threatened, we engage in a more detailed analysis to 
determine whether these standards are indeed met. The identification of 
an SPR does not create a presumption, prejudgment, or other 
determination as to whether the species in that identified SPR is 
endangered or threatened. We must go through a separate analysis to 
determine whether the species is endangered or threatened in the SPR. 
To determine whether a species is endangered or threatened throughout 
an SPR, we will use the same standards and methodology that we use to 
determine if a species is endangered or threatened throughout its 
range.
    Depending on the biology of the species, its range, and the threats 
it faces, it may be more efficient to address the ``significant'' 
question first, or the status question first. Thus, if we determine 
that a portion of the range is not ``significant,'' we do not need to 
determine whether the species is endangered or threatened there; if we 
determine that the species is not endangered or threatened in a portion 
of its range, we do not need to determine if that portion is 
``significant.''
    For the Modoc sucker, we examined whether any of the identified 
threats acting on the species or its habitat are geographically 
concentrated to indicate that the species could be endangered or 
threatened in that area. As stated earlier, we consider the ``range'' 
of Modoc sucker to include an estimated 42.5 mi (68.4 km) of occupied 
habitat in 12 streams in the Turner Creek, Ash Creek, and Goose Lake 
sub-basins of the Pit River. This distribution represents its entire 
known historical range, with the exception of Willow Creek within the 
Ash Creek sub-basin.
    We considered whether any portions of the Modoc sucker range might 
be both significant and in danger of extinction or likely to become so 
in the foreseeable future. To identify whether any portions warrant 
further consideration, we first determine whether there is substantial 
information indicating that (1) the portions may be significant and (2) 
the species may be in danger of extinction in those portions or likely 
to become so within the foreseeable future. One way to identify 
portions that may be significant would be to identify natural divisions 
within the range that might be of biological or conservation 
importance. Modoc sucker inhabit three sub-basins of the Pit River, one 
of which, the Goose Lake sub-basin, is disjoined from the other two 
sub-basins (Turner Creek and Ash Creek sub-basins). These sub-basins 
have the potential to be significant areas to the species due to 
potential geographic isolation. Although the sub-basins have the 
potential to be significant, as described above, threats to populations 
of the species within each of the sub-basins have been ameliorated 
through restoration and active management as discussed above. Surveys 
indicate that Modoc sucker populations have been maintained and are 
well-established and remaining factors that may affect the Modoc sucker 
occur at similarly low levels throughout each sub-basin. There is no 
substantial information indicating the species is likely to be 
threatened or endangered throughout any of the sub-basins. Therefore, 
these portions, the three sub-basins do not warrant further 
consideration to determine whether the species may be endangered or 
threatened in a significant portion of its range.
    Another way to identify portions for further consideration would be 
to consider whether there is substantial information to indicate any 
threats are geographically concentrated in some way that would indicate 
the species could be threatened or endangered in that area. With the 
exception of erosion at some locations, we have determined that threats 
have been ameliorated through restoration and active management as 
discussed above. Some factors may continue to affect Modoc sucker, such 
as drought, but would do so at uniformly low levels across the species 
range such that they are unlikely to result in adverse effects to 
populations of the species and do not represent a concentration of 
threats that may indicate the species could be threatened or endangered 
in a particular area. As noted above, erosion due to past poor grazing 
management still occurs at two sites that make up approximately 4.1 
percent of the Modoc sucker range, and has the potential to adversely 
affect Modoc sucker in those areas. These two areas where erosion is 
still occurring are within different sub-basins and, both collectively 
and per sub-basin, represent a very small fraction of the Modoc 
sucker's range. These areas, individually or collectively, are 
therefore unlikely to constitute a significant portion of the species' 
range. No other natural divisions occur, and no other potential 
remaining threats have been identified that may be likely to cause the 
species to be threatened or endangered in any particular area. We did 
not identify any portions that may be both (1) significant and (2) 
endangered or threatened. Therefore, no portion warrants further 
consideration to determine whether the species may be endangered or 
threatened in a significant portion of its range.
    We have carefully assessed the best scientific and commercial data 
available and determined that the Modoc sucker is no longer in danger 
of extinction throughout all or significant portions of its range, nor 
is it likely to become so in the foreseeable future. As a consequence 
of this determination, we are removing this species from the Federal 
List of Endangered and Threatened Wildlife.

Future Conservation Measures

    Section 4(g)(1) of the Act requires us, in cooperation with the 
States, to implement a monitoring program for not less than 5 years for 
all species that have been recovered and delisted. The purpose of this 
post-delisting monitoring (PDM) is to verify that a species remains 
secure from risk of extinction after the protections of the Act are 
removed, by developing a program that detects the failure of any 
delisted species to sustain itself. If, at any time during the 
monitoring period, data indicate that protective status under the Act 
should be reinstated, we can initiate listing procedures, including, if 
appropriate, emergency listing under section 4(b)(7) of the Act.

Post-Delisting Monitoring Plan

    The Service has developed a final post-delisting monitoring (PDM) 
plan (Service 2015b). In addition, the USFS, CDFW, and ODFW have agreed 
to partner with us in the implementation of the PDM plan. The PDM plan 
is designed to verify that the Modoc sucker remains secure from risk of 
extinction after removal from the Federal List of Endangered and 
Threatened Wildlife by detecting

[[Page 76248]]

changes in its status and habitat throughout its known range. The final 
PDM plan consists of: (1) A summary of the species' status at the time 
of delisting; (2) a summary of the roles of PDM cooperators; (3) an 
outline of the frequency and duration of monitoring; (4) a description 
of monitoring methods and locations; (5) a definition of thresholds or 
triggers for potential monitoring outcomes and conclusions of the PDM 
effort; and (6) an outline of data compilation and reporting 
procedures.
    A multi-state occupancy approach (MacKenzie et al. 2009, entire) 
will be used to estimate the proportion of sites occupied, change in 
site occupancy, and change in abundance of Modoc suckers. Surveys for 
Modoc suckers will be completed following a modified version of a 
sampling protocol developed for Modoc sucker (Reid 2008b) that is 
consistent with the approach used in surveys conducted since 2008. This 
approach will allow for monitoring population status over time as it 
permits the estimation of the proportion of sites (within a stream and 
among all streams) that are occupied and that are in each state of 
abundance (low and high). During occupancy and abundance surveys, we 
will also monitor threats and recruitment. To measure recruitment, we 
will estimate the size of individuals to the nearest centimeter. 
Examination of fish sizes will allow a determination to be made if 
recruitment is occurring over time. Ideally, survey results will 
indicate in diverse size classes of fish, indicating recruitment is 
occurring. Threats, both biotic (for example, nonnative predatory fish) 
and abiotic (for example, excessive sedimentation), will also be 
assessed during surveys (both day and night). Prior to completing 
surveys, sites (pools) within streams will be landmarked and 
georeferenced to allow relocation for subsequent surveys.
    Although the Act has a minimum PDM requirement of 5 years, we will 
monitor Modoc sucker for a 10-year monitoring period to account for 
environmental variability (for example, drought) that may affect the 
condition of habitat and to provide for a sufficient number of surveys 
to document any changes in the abundance of the species. Based on the 
life history of the Modoc sucker, in which individuals mature at age 2+ 
years, a complete survey of previously surveyed areas should be 
conducted every 2 years within the 10-year monitoring period. This will 
allow us to assess changes in abundance or the extent of the species' 
range over time, changes in the level of recruitment of reproducing 
fish into the population, and any potential changes in threats to the 
species. However, if a decline in abundance is observed or a 
substantial new threat arises, PDM may be extended or modified.
    After each complete survey (conducted once every 2 years), the 
Service and its partners will compare the results with those from 
previous surveys and consider the implication of any observed 
reductions in abundance or changes in threats to the species. Within 1 
year of the end of the PDM period, the Service will conduct a final 
internal review and prepare (or contract with an outside entity) a 
final report summarizing the results of monitoring. This report will 
include: (1) A summary of the results from the surveys of Modoc sucker 
occupancy, states of abundance, recruitment, and change in 
distribution; and (2) recommendations for any actions and plans for the 
future. The final report will include a discussion of whether 
monitoring should continue beyond the 10-year period for any reason.
    The final PDM plan and any future revisions will be available on 
our national Web site (https://endangered.fws.gov) and on the Klamath 
Falls Fish and Wildlife Office's Web site (https://www.fws.gov/klamathfallsfwo/).

Required Determinations

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that environmental assessments and environmental 
impact statements, as defined under the authority of the National 
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be 
prepared in connection with listing or reclassification of a species as 
an endangered or threatened species under the Endangered Species Act. 
We published a notice outlining our reasons for this determination in 
the Federal Register on October 25, 1983 (48 FR 49244).

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination With Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
tribes in developing programs for healthy ecosystems, to acknowledge 
that tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to tribes. Two tribes are near the range of the 
Modoc sucker: The Klamath Tribe and the Pitt River Tribe. The Klamath 
Tribe does not have an interest in this species, as it does not inhabit 
their historic reservation lands. We provided the proposed rule to the 
Pit River Tribe for comment. We received the Pit River Tribe's comments 
regarding the delisting of the Modoc sucker, and they disagree that the 
species should be delisted. The Pit River Tribe stated that the Pit 
River and habitat for the Modoc sucker continues to be degraded. We 
disagree with the Tribe's comments regarding the habitat for the 
species. See the Comments from Tribes section, above, for a summary of 
their comments and our response.

References Cited

    A complete list of references cited in this rulemaking is available 
on the Internet at https://www.regulations.gov under Docket No. FWS-R8-
ES-2013-0133 or upon request from the Klamath Falls Fish and Wildlife 
Office (see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this final rule are staff members of the 
Pacific Southwest Regional Office in Sacramento, California, in 
coordination with the Klamath Falls Fish and Wildlife Office in Klamath 
Falls, Oregon.

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

    Accordingly, we amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as set forth below:

PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS

0
1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245, unless 
otherwise noted.

[[Page 76249]]

Sec.  17.11  [Amended]

0
2. Amend Sec.  17.11(h) by removing the entry for ``Sucker, Modoc'' 
under FISHES in the List of Endangered and Threatened Wildlife.


Sec.  17.95  [Amended]

0
3. Amend Sec.  17.95(e) by removing the entry for ``Modoc Sucker 
(Catostomus microps)''.

    Dated: November 30, 2015.
Stephen D. Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-30915 Filed 12-7-15; 8:45 am]
 BILLING CODE 4333-15-P