[Federal Register Volume 79, Number 190 (Wednesday, October 1, 2014)]
[Rules and Regulations]
[Pages 59140-59150]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-23305]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2014-0042; 4500030113]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List Rio Grande Cutthroat Trout as an Endangered or 
Threatened Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
12-month finding on a petition to list the Rio Grande cutthroat trout 
(Oncorhynchus clarkii virginalis) as an endangered or threatened 
species under the Endangered Species Act of 1973, as amended (Act). 
After review of the best available scientific and commercial 
information, we find that listing the Rio Grande cutthroat trout is not 
warranted at this time, and, therefore, we are removing this species 
from our candidate list. However, we ask the public to submit to us any 
new information that becomes available concerning the status of the Rio 
Grande cutthroat trout at any time.

DATES: The finding announced in this document was made on October 1, 
2014.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R2-ES-2014-0042. Supporting 
documentation we used in preparing this finding is available for public 
inspection, by appointment, during normal business hours at the U.S. 
Fish and Wildlife Service, New Mexico Ecological Services Field Office, 
2105 Osuna Rd NE., Albuquerque, NM 87113. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above street address.

FOR FURTHER INFORMATION CONTACT: Wally ``J'' Murphy, Field Supervisor, 
New Mexico Ecological Services Field Office (see ADDRESSES); telephone 
505-346-2525; or facsimile 505-346-2542. If

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you use a telecommunications device for the deaf (TDD), please call the 
Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Background

    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires 
that, for any petition to revise the Federal Lists of Endangered and 
Threatened Wildlife and Plants that contains substantial scientific or 
commercial information that listing the species may be warranted, we 
make a finding within 12 months of the date of receipt of the petition. 
In this finding, we will determine that the petitioned action is: (1) 
Not warranted, (2) warranted, or (3) warranted, but the immediate 
proposal of a regulation implementing the petitioned action is 
precluded by other pending proposals to determine whether species are 
endangered or threatened, and expeditious progress is being made to add 
or remove qualified species from the Federal Lists of Endangered and 
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires 
that we treat a petition for which the requested action is found to be 
warranted but precluded as though resubmitted on the date of such 
finding, that is, requiring a subsequent finding to be made within 12 
months. We must publish these 12-month findings in the Federal 
Register.

Previous Federal Actions

    On February 25, 1998, we received a petition from the Southwest 
Center for Biological Diversity requesting that the Rio Grande 
cutthroat trout be listed as an endangered or threatened species. We 
subsequently published a notice of a 90-day petition finding in the 
Federal Register (63 FR 49062) on September 14, 1998, concluding that 
the petition did not present substantial information indicating that 
listing of the Rio Grande cutthroat trout may be warranted.
    On June 9, 1999, the Southwest Center for Biological Diversity sued 
the Service in regard to our September 14, 1998, 90-day petition 
finding. While this litigation was pending, we received information 
(particularly related to the presence of whirling disease in hatchery 
fish in the wild) that led us to believe that further review of the 
status of the subspecies was warranted. On November 8, 2001, the 
Service and the Southwest Center for Biological Diversity entered into 
a settlement agreement stipulating that the Service would initiate a 
status review for the Rio Grande cutthroat trout; make a determination 
on or before June 3, 2002; and shortly thereafter, publish our 
determination in the Federal Register. On June 11, 2002, after 
reviewing the best available scientific and commercial data, including 
data related to the presence of whirling disease, we published a 
determination that listing of Rio Grande cutthroat trout was not 
warranted (67 FR 39936).
    Subsequently, on February 25, 2003, the Center for Biological 
Diversity (formerly Southwest Center for Biological Diversity), along 
with several other organizations, sued the Service for the 2002 
decision that the subspecies did not warrant listing under the Act. On 
June 7, 2005, the district court ruled that our finding was not 
arbitrary and capricious, but also required that we explain in more 
detail our analysis of ``significant portion of the range.'' The court 
ordered the Service to provide supplemental briefing discussing in more 
detail our analysis of ``significant portion of the range.'' Following 
submission of this briefing, on December 22, 2005, the Court ruled in 
favor of the Service and upheld our interpretation of ``significant 
portion of the range'' and determined that our evaluation of the Rio 
Grande cutthroat trout's status under the listing criteria was not 
arbitrary and capricious. Plaintiffs appealed this decision.
    The appeal was pending with the Tenth Circuit Court of Appeals, 
when other courts issued opinions in regard to decisions for other 
species that required the Service to reexamine our legal position on 
``significant portion of the range.'' On March 16, 2007, the Solicitor 
of the Department of the Interior issued a formal legal opinion titled 
``The Meaning of In Danger of Extinction Throughout All or a 
Significant Portion of Its Range'' (M-37013, U.S. DOI 2007). Because of 
this new formal legal opinion and because of our knowledge of changes 
in status of some populations that we had previously defined as secure 
in our 2002 review, the Service initiated a new status review. We 
subsequently published notices seeking new information concerning the 
status of Rio Grande cutthroat trout on May 22, 2007 (72 FR 28664) and 
August 16, 2007 (72 FR 46030). On May 14, 2008 (73 FR 27900), we found 
that the Rio Grande cutthroat trout warranted listing as an endangered 
or threatened species under the Act based on threats to the subspecies 
related to population fragmentation and isolation, small population 
size, nonnative trout, drought, and fire. However, the Service 
determined that developing a proposed rule to list the Rio Grande 
cutthroat trout as endangered or threatened at that time was precluded 
by other, higher priority listing actions. The subspecies became a 
candidate for listing at that time.
    On September 9, 2011, the Service entered into a settlement 
agreement regarding species on the candidate list in multi-district 
litigation (MDL settlement agreement; Endangered Species Act Section 4 
Deadline Litigation, No. 10-377 (EGS), MDL Docket No. 2165 (D.D.C. May 
10, 2011)). Per the MDL settlement agreement, the Service is required 
to submit a proposed rule or a not warranted 12-month finding to the 
Federal Register for Rio Grande cutthroat trout in Fiscal Year 2014, 
which ends September 30, 2014. This 12-month finding fulfills that 
requirement of the MDL settlement agreement.

Summary of Biological Status

    We completed the Species Status Assessment Report for the Rio 
Grande Cutthroat Trout (SSA Report; Service 2014a, entire), which is 
available online at http://www.regulations.gov, Docket No. FWS-R2-ES-
2014-0042. The SSA Report documents the results of the comprehensive 
biological status review for the Rio Grande cutthroat trout 
(Oncorhynchus clarkii virginalis) and provides an account of the 
subspecies' overall viability and thus extinction risk through a 
forecasting of the number and distribution of surving populations in 
the future (Service 2014a, entire). In the SSA Report we summarized the 
relevant biological data and a description of past, present, and likely 
future risk factors (causes and effects) and conducted a new analysis 
of the viability of the subspecies. The SSA Report provides the 
scientific basis that informs our regulatory decision regarding whether 
this subspecies should be listed as endangered or threatened under the 
Act. This decision involves the application of standards within the 
Act, its implementing regulations, and Service policies (see Finding). 
The SSA Report contains the risk analysis on which this finding is 
based, and the following discussion is a summary of the results and 
conclusions from the SSA Report.
    Rio Grande cutthroat trout (a subspecies of cutthroat trout) 
inhabit high-elevation streams in New Mexico and southern Colorado, 
where they need clear, cold, highly oxygenated water; clean gravel 
substrates; a network of pools and runs; and an abundance of food 
(typically aquatic and terrestrial invertebrates) to complete their 
life history. The subspecies needs multiple resilient populations 
widely distributed across its range to maintain its persistence into 
the future and to avoid extinction. Resilient populations require long, 
continuous, suitable stream

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habitats to support large numbers of individuals and to withstand 
stochastic events; the populations should be free from the impacts of 
nonnative trout. The resilient populations (the term resiliency is 
defined below) should be distributed in each of the four geographic 
management units (GMUs) where the subspecies currently occurs. This 
distributional pattern will provide redundancy and representation 
(these terms are defined below) to increase the probability that the 
subspecies will withstand future catastrophic events and maintain 
future adaptive capacity in terms of genetic and ecological diversity 
(Service 2014a, Table ES-1). The likelihood of the Rio Grande cutthroat 
trout's persistence depends upon the number of populations, its 
resilience to threats, and its distribution. As we consider the future 
viability of the subspecies, more populations with greater resiliency 
and wider geographic distributions are associated with higher overall 
subspecies viability.
    The Rio Grande cutthroat trout historically occurred in New Mexico 
and southern Colorado. Its distribution has been divided into five GMUs 
reflecting major hydrologic divisions. The subspecies no longer occurs 
in one GMU, the Caballo GMU, where only one population was historically 
known. The remaining four GMUs are managed by the States of Colorado 
and New Mexico and other agencies as separate units to maintain genetic 
and ecological diversity within the subspecies where it exists and to 
ensure representation of the subspecies across its historical range. 
GMUs were not created to necessarily reflect important differences in 
genetic variability, although fish in the Pecos and Canadian GMUs do 
exhibit some genetic differentiation from those in the Rio Grande basin 
GMUs. From a rangewide perspective, multiple Rio Grande cutthroat trout 
populations should be dispersed throughout the various GMUs to maintain 
subspecies viability and to reduce the likelihood of extinction.
    Currently the subspecies is distributed in 122 populations across 
the four GMUs (ranging from 10 to 59 populations per GMU), and most of 
the populations are isolated from other populations. The total amount 
of currently occupied stream habitat is estimated to be about 11 
percent of the historically occupied range. This large decline in 
distribution and abundance is primarily due to the impacts of the 
introduction of nonnative trout. Nonnative rainbow trout (O. mykiss) 
and other nonnative subspecies of cutthroat trout invaded most of the 
historical range of the Rio Grande cutthroat trout and resulted in 
their extirpation because the nonnative trout readily hybridize with 
Rio Grande cutthroat trout. In addition, brown trout (Salmo trutta) and 
brook trout (Salvelinus fontinalis) have also displaced Rio Grande 
cutthroat trout in some historical habitats through competition and 
predation pressures. We evaluated the current condition of the 122 
populations and categorized the condition of each population based on 
the absence of nonnative trout, the effective population size, and the 
occupied stream length. Fifty-five populations were in either the 
``best'' or ``good'' condition in this categorization. Table ES-2 in 
the SSA Report identifies the number of populations placed in each 
category by GMU (see Service 2014a, Chapter 3 for a description of the 
categories).
    We next reviewed the past, current, and future factors that could 
affect the persistence of Rio Grande cutthroat trout populations. Seven 
risk factors were evaluated in detail to estimate their individual and 
cumulative contributions to the overall risk to the subspecies' 
viability. We focused on these seven factors because they were found to 
potentially have population-level effects on the subspecies (Service 
2014a, Chapter 4, Appendix B, and Appendix C). The seven factors were:
    (1) Demographic Risk: Small population sizes are at greater risk 
from inbreeding, demographic fluctuations, and reduced genetic 
diversity, and they are more vulnerable to extirpation from other risk 
factors.
    (2) Hybridizing Nonnative Trout: Nonnative rainbow and other 
cutthroat trout subspecies have historically been introduced throughout 
the range of Rio Grande cutthroat trout for recreational angling, and 
they are known to readily hybridize with Rio Grande cutthroat trout. 
Climate change may exacerbate this risk factor as warmer waters may 
make high-elevation habitats more susceptible to invasion by rainbow 
trout.
    (3) Competing Nonnative Trout: Brook and brown trout compete with 
Rio Grande cutthroat trout for food and space, and larger adults will 
prey upon young Rio Grande cutthroat trout.
    (4) Wildfire: Ash and debris flows that occur after a wildfire can 
eliminate populations of fish from a stream, and wildfires within the 
range of Rio Grande cutthroat trout have depressed or eliminated fish 
populations. As drought frequency increases due to climate change, dry 
forests are more likely to burn and burn hotter than they have in the 
past.
    (5) Stream Drying: Drying of streams occupied by Rio Grande 
cutthroat trout populations may occur as a result of drought or, in a 
few cases, water withdrawals. Drought frequency is expected to increase 
as a result of climate change due to a combination of increased summer 
temperatures and decreased precipitation.
    (6) Disease: Whirling disease damages cartilage, killing young fish 
or causing infected fish to swim in an uncontrolled whirling motion, 
making it impossible to avoid predation or feed.
    (7) Water Temperature Changes: Changes in air temperature and 
precipitation patterns expected from climate change could result in 
elevated stream temperatures that make habitat unsuitable for Rio 
Grande cutthroat trout to complete their life history.
    We considered other potential factors as well, including hydrologic 
changes related to future climate change, effects to habitat related to 
land management, and angling. Our review of the best available 
information did not demonstrate a relationship between hydrologic 
changes and the potential negative effects on the subspecies to allow 
for reasonably reliable conclusions; therefore, we did not consider 
that factor further. We found that land management activities are not 
likely to have a measurable population-level effect on the subspecies, 
and angling was also not found to be a substantial factor affecting the 
subspecies. Therefore, these factors were not evaluated further in our 
analysis (Service 2014a, Chapter 4).
    We included future management actions as an important part of our 
overall assessment. The Rio Grande Cutthroat Trout Conservation Team 
(Conservation Team) is composed of biologists from Colorado Parks and 
Wildlife (CPW), New Mexico Department of Game and Fish (NMDGF), U.S. 
Bureau of Land Management (BLM), U.S. Forest Service (USFS), National 
Park Service (NPS), Mescalero Apache Nation, Jicarilla Apache Nation, 
Taos Pueblo, and the Service. The Conservation Team developed the 
Conservation Agreement and Strategy in 2013 (revised from the previous 
Conservation Agreements in 2003 and 2009), which formalized many 
ongoing management actions. The Conservation Agreement and Strategy 
includes activities such as stream restorations, barrier construction 
and maintenance, nonnative species removals, habitat improvements, 
public outreach, and database management. Over the 10-year life of the 
Conservation Agreement and Strategy, the Conservation Team has 
committed to

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restoration of between 11 and 20 new Rio Grande cutthroat trout 
populations to historical habitat. We included these activities in our 
analysis of the future status of the subspecies over the next 10 years 
(see PECE Analysis, below) and projected various scenarios of active 
management beyond that.
    We developed a species status assessment model to quantitatively 
incorporate the risks of extirpation from the seven risk factors listed 
above (including cumulative effects) in order to estimate the future 
probability of persistence of each extant population of Rio Grande 
cutthroat trout. We used this model to forecast the future status of 
the Rio Grande cutthroat trout in a way that addresses viability in 
terms of the subspecies' resiliency, redundancy, and representation. As 
a result, we developed two distinct modules. Module 1 estimates the 
probability of persistence for each Rio Grande trout population by GMU 
for three future time periods (2023, 2040, and 2080) under a range of 
conditions, and Module 2 estimates the number of surviving populations 
by GMU for the three future time periods under several scenarios 
related to future management actions and the effects of climate change. 
A detailed explanation of the methodology used to develop the model is 
provided in Appendix C of the SSA Report (Service 2014a, Appendix C), 
and the results are summarized in Chapter 5 (Service 2014a, Chapter 5).
    We used the results of this analysis to describe the viability of 
the Rio Grande cutthroat trout (viability is the ability of a species 
to persist over time and thus avoid extinction; ``persist'' means that 
the species is expected to sustain populations in the wild beyond the 
end of a specified time period) by characterizing the status of the 
subspecies in terms of its resiliency, redundancy, and representation.
    Resiliency is having sufficiently large populations for the 
subspecies to withstand stochastic events. We measured resiliency at 
the population scale for the Rio Grande cutthroat trout by quantifying 
the persistence probability of each extant population under a range of 
assumed conditions. As expected because of the way the status 
assessment model was developed to forecast linearly increasing risks 
over time, all of the population persistence probabilities decrease in 
our three time periods. Our results do not necessarily mean that any 
one population will, in fact, be extirpated by 2080; they simply 
reflect the risks that we believe the populations face due to their 
current conditions and the risk factors influencing their resiliency.
    Rangewide, the resiliency of the subspecies has declined 
substantially due to the large decrease in overall distribution in the 
last 50 years. In addition, the remnant Rio Grande cutthroat trout 
populations are now mostly isolated to headwater streams due to the 
fragmentation that has resulted from the historical, widespread 
introduction of nonnative trout across the range of Rio Grande 
cutthroat trout. Therefore, if an extant population is extirpated due 
to a localized event, such as a wildfire and subsequent debris flow, 
there is little to no opportunity for natural recolonization of that 
population. This reduction in resiliency results in a lower probability 
of persistence for the subspecies as a whole. To describe the remaining 
resiliency of the subspecies, we evaluated the individual populations 
in detail to understand the subspecies' overall capacity to withstand 
stochastic events.
    Redundancy is having a sufficient number of populations for the 
subspecies to withstand catastrophic events. For the Rio Grande 
cutthroat trout, we measured redundancy based our forecasting of the 
number of populations persisting across the subspecies' range. The 
results suggest that, depending on the particular scenario related to 
risk factors and restoration efforts, the overall number of populations 
may decline to some extent by 2080 (Service 2014a, Table ES-1, Column 
4). We are focusing on the estimates for 2080, because if the 
subspecies has sufficient redundancy by 2080, it will also have 
sufficient redundancy in the more recent time periods. Rangewide there 
are currently 122 populations, and we forecast between 50 and 132 
populations surviving in 2080 (with an intermediate forecast of 68 
populations). The wide range in the estimated number of surviving 
populations is due to the various projections of management and climate 
change intensity. Some GMUs may decline more than others; for example, 
our forecasts suggest the Lower Rio Grande GMU may have the largest 
decline. We estimate the current 59 populations in this GMU could be 
between 21 and 47 populations by 2080 (with an intermediate forecast of 
28 populations). The GMU with the least populations, the Canadian GMU, 
is forecasted to change from 10 current populations to between 3 and 14 
populations by 2080 (with an intermediate forecast of 6 populations).
    Representation is having the breadth of genetic and ecological 
diversity of the subspecies to adapt to changing environmental 
conditions. For the Rio Grande cutthroat trout, we evaluated 
representation based on the extent of the geographical range expected 
to be maintained in the future as indicated by the populations 
occurring within each GMU for a measure of ecological diversity. For 
genetic diversity, there are important genetic differences between the 
Rio Grande basin populations and the populations in the Canadian and 
Pecos GMUs (though the Pecos and Canadian GMUs are not genetically 
different from each other). The variation in persistence probabilities 
is distributed across the GMU so that none of the risk is particularly 
associated with any particular geographic area within the GMU. 
Combined, the Canadian and Pecos GMUs are forecasted to have 8 to 30 
populations surviving in 2080 (with an intermediate forecast of 14 
populations).
    We used the best available information to forecast the likely 
future condition of the Rio Grande cutthroat trout. Our goal was to 
describe the viability of the subspecies quantitatively in a way that 
characterizes the needs of the subspecies in terms of resiliency, 
redundancy, and representation. We considered the possible future 
condition of the subspecies out to about 65 years from the present (see 
discussion regarding foreseeable future, below, in the Threatened 
Species Throughout Range section). We considered nine different 
scenarios that spanned a range of potential conditions that we believe 
are important influences on the status of the subspecies. Our results 
describe a range of possible conditions in terms of the probability of 
persistence of individual populations across the GMUs and a forecast of 
the number of populations surviving in each GMU.
    Although we evaluated nine different scenarios in our assessment, 
for this finding we report the foreseeable worse case and best case 
results that show the full range of outcomes. In each of the relevant 
conclusions, we focus on the foreseeable worse case results. Logically, 
if the subspecies does not warrant listing under our worst-case 
scenario, the eight remaining scenarios will also not warrant listing 
the subspecies. We also provide in this finding the best case results 
of each scenario for each of the relevant conclusions. This provides a 
context for the range of possible outcomes for the future populations 
of the subspecies.
    Considering the worst case scenario allowed us to view the 
viability of the subspecies under conditions of low management and 
severe climate change, which are aspects of the model with high 
uncertainty. None of our ``worst case scenario'' forecasts results in a

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predicted loss of all of the populations within any of the GMUs. 
Therefore, at a minimum, our results suggest the subspecies will have 
persisting populations in 2080 across its range. Most of the scenarios 
generally show a declining number of populations over time. However, 
the rate of this decline, or whether it occurs at all, depends largely 
on the likelihood of future management actions occurring, the most 
important of which are the future restoration and reintroduction of 
populations within the historical range and the control of nonnative 
trout. While other factors are important to each population, the future 
management efforts will probably determine the future viability of the 
Rio Grande cutthroat trout. These conservation efforts were an 
important consideration in the SSA analysis.

PECE Analysis

    The Service's 2003 Policy for Evaluation of Conservation Efforts 
When Making Listing Decisions (PECE) provides guidance on how to 
evaluate conservation efforts that have not yet been fully implemented 
or have not yet demonstrated effectiveness (68 FR 15100, March 28, 
2003). The purpose of PECE is to ensure consistent and adequate 
evaluation of recently formalized conservation efforts when making 
listing decisions. The policy presents criteria for evaluating the 
certainty of implementation and the certainty of effectiveness for such 
conservation efforts. We evaluated two formalized conservation efforts 
and their specific conservation measures under PECE (see PECE 
Evaluation, Service 2014b, entire): the Conservation Agreement and 
Strategy and the Vermejo Park Ranch Candidate Conservation Agreement 
with Assurances (Vermejo CCAA). We found the specific conservation 
measures in each of the formalized conservation efforts to have high 
levels of certainty of implementation and effectiveness and both were 
considered as part of the basis for our listing determination for the 
Rio Grande cutthroat trout. Below is a brief summary of each effort, 
and more detail is provided in our separate PECE analysis (Service 
2014b, entire).
Conservation Agreement and Strategy
    The Conservation Agreement and Strategy for the Conservation of Rio 
Grande Cutthroat Trout was signed in 2013 by NMDGF, CPW, USFS, NPS, 
BLM, Mescalero Apache Nation, Jicarilla Apache Nation, Taos Pueblo, and 
the Service. The 2013 Conservation Agreement and Strategy was a 
revision to the Conservation Agreement that was originally signed in 
2003. The measures in the Conservation Agreement and Strategy are made 
up of cooperative efforts by the parties to develop and implement the 
necessary conservation measures for the Rio Grande cutthroat trout to 
have sufficient resiliency, representation, and redundancy to provide 
for long-term viability. Conservation measures include:
    (1) Identify and characterize all Rio Grande cutthroat trout 
conservation populations and occupied habitat. Characterization 
includes gathering data on Rio Grande cutthroat trout density, length 
of occupied habitat, genetic status, and habitat quality.
    (2) Secure and enhance conservation populations.
    (3) Restore populations.
    (4) Secure and enhance watershed conditions.
    (5) Public outreach.
    (6) Data sharing.
    (7) Coordination.
    Throughout the 10-year life of the Conservation Agreement and 
Strategy, the parties have committed to restoring 11 to 20 new 
populations of Rio Grande cutthroat trout rangewide. In our PECE 
analysis, we found that the conservation efforts in the Rio Grande 
Cutthroat Trout Conservation Agreement and Strategy have a high level 
of certainty of implementation and effectiveness because of the 
demonstrated ability of the participants in carrying out an effective 
conservation program for this subspecies. Therefore, we considered 
these efforts as part of the basis for our listing determination for 
the Rio Grande cutthroat trout under the Act.
Vermejo CCAA
    The goal of the Vermejo CCAA, signed in 2013, is to facilitate and 
promote the conservation and restoration of the Rio Grande cutthroat 
trout on certain non-Federal lands owned by Vermejo Park Ranch, LLC. 
Vermejo Park Ranch consists of 590,823 acres (2,391 square kilometers) 
in Costilla County, Colorado, and Taos County, New Mexico, managed for 
conservation, hunting, and fishing. Vermejo Park Ranch is implementing 
the conservation measures specified in the Vermejo CCAA and has 
received assurances from the Service that if the Rio Grande cutthroat 
trout is listed under the Act, no further conservation measures will be 
required. Conservation measures being implemented by Vermejo Park Ranch 
include nonnative trout removal, Rio Grande cutthroat trout 
reintroductions, and increasing existing populations so they are 
capable of migrating among tributaries. Overall, the project 
encompasses the restoration of approximately 190 kilometers (118 miles) 
of stream habitat, and to date nearly 100 kilometers (62 miles) of 
restoration have been completed and are being monitored. In our PECE 
analysis, we found that the conservation efforts in the Vermejo CCAA 
have a high level of certainty of implementation and effectiveness 
because of the demonstrated ability of the Vermejo Park Ranch for 
carrying out effective conservation actions for the subspecies. 
Therefore, we considered these conservation efforts as part of the 
basis for our listing determination for the Rio Grande cutthroat trout.

Finding

Standard for Review

    Section 4 of the Act, and its implementing regulations at 50 CFR 
part 424, set forth the procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(b)(1)(a), the Secretary is to make endangered or threatened 
determinations required by subsection 4(a)(1) solely on the basis of 
the best scientific and commercial data available to her after 
conducting a review of the status of the subspecies and after taking 
into account conservation efforts by States or foreign nations. The 
standards for determining whether a species is endangered or threatened 
are provided in section 3 of the Act. An endangered species is any 
species that is ``in danger of extinction throughout all or a 
significant portion of its range.'' A threatened species is any species 
that is ``likely to become an endangered species within the foreseeable 
future throughout all or a significant portion of its range.'' Per 
section 4(a)(1) of the Act, in reviewing the status of the species to 
determine if it meets the definition of endangered or of threatened, we 
determine whether any species is an endangered species or a threatened 
species because of any of the following 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; and (E) other natural or manmade 
factors affecting its continued existence.
    Until recently the Service has presented its evaluation of 
information under the five listing factors in an outline format, 
discussing all of the information relevant to any given factor and 
providing a factor-specific conclusion before moving to the next 
factor. However, the Act does not

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require findings under each of the factors, only an overall 
determination as to the species' status (for example, endangered 
species, threatened species, or not warranted). Ongoing efforts to 
improve the efficiency and efficacy of the Service's implementation of 
the Act have led us to present this information in a different format 
that we find leads to greater clarity in our understanding of the 
science, its uncertainties, and our application of our statutory 
framework to that science. Therefore, while the presentation of 
information in this document differs from past practice, it differs in 
format only. We have evaluated the same body of information that, in 
the past, we have discussed under an outline of the five listing 
factors. In this analysis, we are applying the same information 
standard, and we are applying the same statutory framework in reaching 
our conclusions and ultimate determination of the status of the 
subspecies under the Act.

Summary of Analysis

    The biological information we reviewed and analyzed as the basis 
for our findings is documented in the Rio Grande Cutthroat Trout 
Species Status Assessment Report (Service 2014a, entire), a summary of 
which is provided in the background of this finding. The projections 
for the number of future persisting populations are based on the 
Species Status Assessment Model (SSA Model; Service 2014a, Chapter 5 
and Appendix C), which incorporates the potential risk factors (in 
other words, threats) that were found to have possible population-level 
effects. The risk factors we evaluated in detail are demographic risk 
(Factor E from the Act), nonnative trout (Factors C and E), wildfire 
(Factor A), stream drying (Factor A), disease (Factor C), and water 
temperature changes (Factor A). For four of the factors (hybridizing 
nonnative trout, wildfire, stream drying, and water temperature 
changes), we also considered the exacerbating effects of climate 
change. We reviewed, but did not evaluate in further detail because of 
a lack of population-level effects, the effects of land management 
activities and hydrologic changes (Factor A), and recreational angling 
(Factor B).
    The overall results of the status assessment found that the best 
available information indicates that large declines (approximately 89 
percent loss) in the distribution and abundance of Rio Grande cutthroat 
trout have occurred in the past 50 years or so due mainly to the 
impacts from introduced nonnative trout. This declining trend has been 
abated in recent years to a large extent due to management efforts to 
control nonnative trout and limit new introductions and the spread of 
nonnative trout. However, the results of the past impacts have left the 
Rio Grande cutthroat trout in a remnant of its former habitat, which is 
now primarily high-elevation headwater streams. The purpose of the 
status assessment was to characterize the future viability of the 
subspecies in the face of this reduced distribution and the ongoing 
factors that put populations at risk of extirpation.
    In the SSA Report, we described the viability of the Rio Grande 
cutthroat trout in terms of redundancy, representation, and resiliency 
(Service 2014a, Chapter 5). These characteristics have all been reduced 
in the subspecies because of the historical declines in its 
distribution and abundance. In addition, the reduction in population 
sizes and the isolated nature of most remaining populations makes many 
of the potential stressors to the Rio Grande cutthroat trout more 
significant than they would have been historically. This is because 
small populations are more susceptible to extirpation from negative 
events, whether those events are natural or human-caused. In addition, 
in the event of a local extirpation due to a negative stochastic event, 
isolated populations are unable to be recolonized by natural dispersal 
from nearby populations. Therefore, the Rio Grande cutthroat trout has 
an overall reduced viability compared to historical conditions.
    Our forecasts take into consideration a range of the likely number 
of populations that could be restored in the future through work of the 
agencies under the multi-agency Conservation Agreement and Strategy. 
Numerous conservation efforts are ongoing for Rio Grande cutthroat 
trout. The conservation measures for the Conservation Agreement and 
Strategy and the Vermejo CCAA are evaluated in the PECE analysis 
(Service 2014b) discussed above. The formal agreements extend for 10 
years, but in the case of the Conservation Agreement and Strategy, in 
particular, we expect efforts to continue further into the future. We 
cannot predict the number and type of efforts that will be performed in 
the future with as much accuracy as the Conservation Agreement and 
Strategy specifies for the next 10 years. However, given the history of 
the Conservation Team and the motivation of the States in the 
conservation of this subspecies (Service 2014b), we expect management 
efforts to continue past the life of the Conservation Agreement and 
Strategy, either formally (through renewal of the Conservation 
Agreement and Strategy) or informally. As such, we have included 
varying levels of conservation efforts in the different scenarios of 
our model forecasting.

Application of Analysis to Determinations

    Our status assesment characterized Rio Grande cutthroat trout 
viability (future persistence) in terms of number and distribution of 
populations expected to persist through 2080. These outputs form the 
basis for our determinations under the Act. Because of uncertainty, 
mainly related to climate change and the level of future conservation 
efforts, our forecasts include a variety of scenarios. For these 
findings, we refer to our results under the best and worst case 
scenarios over two time horizons: 2023 and 2080. The fundamental 
question before the Service is whether the projections of extinction 
risk, described in terms of the number of future populations and their 
distribution (taking into account the risk factors and their effects on 
those populations), indicate that the subspecies warrants protection as 
endangered or threatened under the Act. The lower the number and 
smaller the distribution of the persisting populations, the higher the 
extinction risk and lower the overall viability. In making our 
determinations, we focused on the worst case scenario because, if the 
worst case scenario does not rise to a level for which the subspecies 
meets the definition of an endangered or a threatened species, then the 
more optimistic forecasts are considerably better and likewise would 
not warrant an endangered or threatened conclusion. We also included 
the best case scenario outcome in order to provide context of the 
likely range of the number of persisting populations of the subspecies.
    As described in the determinations below, we first evaluated 
whether the Rio Grande cutthroat trout is in danger of extinction 
throughout its range now (an endangered species). We then evaluated 
whether the subspecies is likely to become in danger of extinction 
throughout its range in the foreseeable future (a threatened species). 
We considered future voluntary conservation efforts in the information 
used in these determinations, consistent with PECE. We finally 
considered whether the Rio Grande cutthroat trout is an endangered or 
threatened species in a significant portion of its range (SPR).

[[Page 59146]]

Endangered Species Throughout Range

Standard
    Under the Act, an endangered species is any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range.'' Because of the fact-specific nature of listing determinations, 
there is no single metric for determining if a species is currently in 
danger of extinction. We used the best available scientific and 
commercial information to evaluate the viability (and thus risk of 
extinction) for the Rio Grande cutthroat trout to determine if it meets 
the definition of an endangered species. In this finding, we used a 
projection of the number and distribution of populations to measure the 
Rio Grande cutthroat trout's viability and then determine the 
subspecies' status under the Act.
Evaluation and Finding
    Our review found that there are currently 122 existing populations 
of the Rio Grande cutthroat trout in four GMUs. We consider each of 
these populations genetically pure enough to be Rio Grande cutthroat 
trout; that is, each population has 90 percent or more of the native 
Rio Grande cutthroat trout genes. To assess the current status of these 
populations, we sorted each of them into four categories to consider 
their current status, which was based on effective population size, 
occupied stream length, presence of competing nonnative trout, and 
presence of hybridizing nonnative trout. We categorized 55 of the 
populations (45 percent) as currently in the best or good condition of 
having no nonative trout, relatively large effective population sizes, 
and relatively long occupied stream lengths (Service 2014a, pp. 14-15). 
This current number of populations in the best or good condition 
existing across the subspecies' range provides resiliency (45 percent 
of populations considered sufficiently large to withstand stochastic 
events), redundancy (55 populations spread across all four extant GMUs 
to withstand catastrophic events), and representation (multiple 
populations are persisting across the range of the subspecies to 
maintain ecological and genetic diversity).
    The Rio Grande cutthroat trout also historically occurred in a 
fifth GMU--the Caballo GMU. We only know of one historical population 
in this GMU, which was extirpated more than 30 years ago. With only one 
population, this area would not have significantly contributed to the 
resiliency and redundancy of the subspecies. However, it could have had 
some important genetic or ecological diversity that would have 
contributed to the adaptive capacity of the subspecies. Losing this 
population likely lowered the overall viability of the subspecies but 
would not be a substantial enough impact rangewide to meaningfully 
increase the overall risk of extinction of the Rio Grande cutthroat 
trout.
    To further consider the status of the Rio Grande cutthroat trout, 
we analyzed the condition of the subspecies over the next 10 years to 
evaluate its viability. In 2023, we projected an estimated range of 
between 104 and 131 populations will persist under worst case and best 
case scenarios, respectively. According to our forecasts, these 
populations would be distributed throughout the subspecies' range, with 
multiple populations persisting in all four of the currently extant 
GMUs (see Service 2014a, pp. 44-45 for complete results). Therefore, 
because this worst case estimate of the number and distribution of 
populations provides resiliency, representation, and redundancy for the 
subspecies, we conclude the subspecies does not meet the definition of 
an endangered species under the Act. Although the subspecies has 
experienced substantial reduction from its historical distribution, the 
number of Rio Grande cutthroat trout populations currently persisting 
and expected to persist in the next 10 years across its range does not 
put the subspecies in danger of extinction.

Threatened Species Throughout Range

    Having found that the Rio Grande cutthroat trout is not an 
endangered species throughout its range, we next evaluated whether the 
subspecies is a threatened species throughout its range.
Standard
    Under the Act, a threatened species is any species that is ``likely 
to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range.'' The foreseeable 
future refers to the extent to which the Secretary can reasonably rely 
on predictions about the future in making determinations about the 
future conservation status of the species (U.S. Department of Interior, 
Solicitor's Memorandum, M-37021, January 16, 2009). A key statutory 
difference between a threatened species and an endangered species is 
the timing of when a species may be in danger of extinction, either now 
(endangered species) or in the foreseeable future (threatened species).
Evaluation and Finding
    In considering the foreseeable future, our analysis used two 
timeframes to forecast the status of the Rio Grande cutthroat trout as 
measured by the number of possible surviving populations based on the 
risk factors and conservation efforts the subspecies is facing. We 
forecasted out to the years 2040 (about 25 years from present) and 2080 
(about 65 years from present). We based these timeframes on the outputs 
of downscaled climate forecasting models that often project climate 
scenarios to the year 2080. Since potential effects of climate change 
were important considerations in our status assessment, it was 
necessary to consider a long enough timeframe to adequately evaluate 
those potential effects. The 2080 timeframe represents about 13 to 21 
Rio Grande cutthroat trout generations and is a reasonably long time to 
consider for potential future effects of stressors on populations of 
the subspecies. This timeframe also represents our outermost estimate 
for forecasting, where our confidence decreases in our ability to 
forecast future environmental conditions related to the risk factors 
evaluated and to the responses of Rio Grande cutthroat trout 
populations.
    To assist us in evaluating the status of the subspecies in the 
foreseeable future, we considered the risk factors that we found to 
have potential population-level effects over time. These future risk 
levels were incorporated into our status assessment model to forecast 
the number of surviving populations into the foreseeable future. We 
increased the risk levels linearly over time to account for the 
cumulative increase in the risks of chance events occurring in the 
future. In addition, for four risk factors (hybridizing nonnative 
trout, wildlife, stream drying, and water temperature) we provided a 
further increase in risks over time to account for the potential 
effects of climate change. We used our best professional judgment to 
estimate the effects of increasing risks due to climate change. In 
addition, because of the high uncertainty associated with climate 
change we considered a ``moderate'' and a ``severe'' effect of climate 
change. For the moderate climate change effect, we increased the risk 
function over time by 5 percent for the 2040 forecast and 10 percent 
for the 2080 forecast. For the severe climate change effect, we 
increased the risk function over time by 20 percent for the 2040 
forecast and 40 percent for the 2080 forecast, as explained in greater 
detail in our SSA Report. We also included management activities in our

[[Page 59147]]

analysis of the future status of the subspecies over the next 10 years 
(see PECE Analysis, above), and projected various scenarios of active 
management beyond that.
    In 2080, our model forecasted 50 to 132 populations will persist 
rangewide under our worst and best case scenarios, respectively, with 
multiple populations in all four of the currently extant GMUs (Service 
2014a, pp. 44-48). Therefore, because this worst-case forecast of the 
number and distribution of populations provides resiliency, redundancy, 
and representation for the subspecies, we conclude the subspecies is 
not likely to become in danger of extinction in the foreseeable future. 
Therefore, we find that the subspecies does not meet the definition of 
a threatened species under the Act.

Endangered or Threatened in a Significant Portion of the Range

    Having found that the Rio Grande cutthroat trout is not an 
endangered or threatened species throughout its range, we next 
evaluated whether the subspecies warrants listing based on any 
significant portion of the subspecies' range.
Standard
    Under the Act and our implementing regulations, a species may 
warrant listing if it is an endangered or a threatened species 
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 of any species of vertebrate fish or wildlife which interbreeds 
when mature.'' We published a final policy interpretating the phrase 
``significant portion of its range'' (79 FR 37578, July 1, 2014). The 
final policy states that (1) if a species is found to be an endangered 
or a threatened species throughout a significant portion of its range, 
the entire species is listed as an endangered 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 an endangered or a 
threatened species 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 NMFS makes any particular status 
determination; and (4) if a vertebrate species is an endangered or a 
threatened species throughout an SPR, and the population in that 
significant portion is a valid distinct population segment (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 an 
endangered nor a threatened species throughout all of its range, we 
determine whether the species is an endangered or a threatened species 
throughout a significant portion of its range. If it is, we list the 
species as an endangered 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 either 
an endangered or a threatened species. 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 foreseeable future. 
Answering these questions in the affirmative is not a determination 
that the species is an endangered or a threatened species 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 an 
endangered or a threatened species. We must go through a separate 
analysis to determine whether the species is an endangered or a 
threatened species in the SPR. To determine whether a species is an 
endangered or a threatened species throughout an SPR, we will use the 
same standards and methodology that we use to determine if a species is 
an endangered or a threatened species 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 an endangered or a threatened species 
there; if we determine that the species is not an endangered or a 
threatened species in a portion of its range, we do not need to 
determine if that portion is ``significant.''
Evaluation
    Our SSA Report and supporting model (Service 2014a, Appendix C) 
evaluated population persistence (i.e., resiliency), incorporating the 
threats to the populations, within the four extant GMUs. Additionally, 
our description of the viability of the subspecies considered 
resiliency, representation, and redundancy in terms of the expected 
persistence of future populations at the GMU spatial scale. Therefore, 
our existing analysis quantitatively forecasts the future condition of 
Rio Grande cutthroat trout in a way that addresses viability in terms 
of the subspecies' resiliency, redundancy, and representation. Because 
the analysis was conducted by GMU, we are able to use the model's

[[Page 59148]]

output to analyze whether there is a significant portion of the range 
that is more vulnerable to extirpation than other parts of the range.
    Therefore, the following evaluation first considers whether each of 
the four extant GMUs may be significant under our definition of SPR. In 
other words, we evaluated whether that GMU's contribution to the 
viability of the Rio Grande cutthroat trout is so important that, 
without the members in that GMU, the subspecies would be in danger of 
extinction, or likely to become so in the foreseeable future, 
throughout all of its range. For the GMUs that we determined could meet 
this standard of significance, we then considered whether the 
forecasted future condition of that GMU, based on our species status 
assessment, would be an endangered or a threatened species.
    Rio Grande Headwaters GMU--The Rio Grande Headwaters GMU contains 
34 percent (41 of 122) of the extant Rio Grande cutthroat trout 
rangewide populations. If the populations in this GMU were all 
extirpated, the subspecies in the remainder of the range could be an 
endangered or threatened species because of the effects to the 
subspecies' viability due to a substantial reduction in redundancy 
(loss of large number of populations from a large portion of the 
range). Therefore, the Rio Grande Headwaters GMU could be significant 
according to our definition of SPR under the Act.
    We next evaluated whether the Rio Grande Headwaters GMU is 
endangered or threatened. Our review found that there are currently 41 
existing populations of the Rio Grande cutthroat trout in the Rio 
Grande Headwaters GMU. To assess the current status of these 
populations, we sorted each of them into four categories to consider 
their current status, which was based on effective population size, 
occupied stream length, presence of competing nonnative trout, and 
presence of hybridizing nonnative trout. We categorized 19 of the 41 
populations (46 percent) as currently in the best or good condition 
(Service 2014a, pp. 14-15). This number of reasonably resilient 
populations within this GMU provides resiliency (46 percent of 
populations considered sufficiently large to withstand stochastic 
events), redundancy (19 populations in the GMU to withstand 
catastrophic events), and representation (multiple populations are 
persisting within the GMU to maintain ecological and genetic 
diversity).
    To consider the current risk of extinction of the Rio Grande 
cutthroat trout, we analyzed the condition of this potential SPR over 
the next 10 years to evaluate its viability (and thus its risk of 
extinction) and considered all threats with possible population-level 
effects. In 2023, we projected 41 to 49 populations will persist in the 
Rio Grande Headwaters GMU under our worst and best case scenarios, 
respectively (Service 2014a, p. 46). Therefore, because the worst case 
scenario forecast of the number and distribution of populations 
provides resiliency, representation, and redundancy for the subspecies 
in the Rio Grande Headwaters GMU, we conclude the subspecies does not 
meet the definition of an endangered species under the Act.
    Having found that the Rio Grande cutthroat trout is not endangered 
in the Rio Grande Headwaters GMU, we next evaluated whether the 
subspecies is threatened in this potential SPR. As with the subspecies 
rangewide (and for the same reasons), we used about 65 years from 
present, the year 2080, as the foreseeable future to consider whether 
the potential SPR is likely to become an endangered species. We also 
used the same rationale for future forecasting of persisting 
populations. In 2080, we forecasted 21 to 55 populations will persist 
in the Rio Grande Headwaters GMU under our worst and best case 
scenarios, respectively (Service 2014a, p. 46). Therefore, because the 
worst case scenario forecast of the number and distribution of 
populations provides resiliency, representation, and redundancy for the 
subspecies in the Rio Grande Headwaters GMU, we conclude the subspecies 
does not meet the definition of a threatened species under the Act.
    Lower Rio Grande GMU--The Lower Rio Grande GMU contains 48 percent 
(59 of 122) of the extant Rio Grande cutthroat trout rangewide 
populations. If the populations in this GMU were all extirpated, the 
subspecies in the remainder of the range could be an endangered or 
threatened species because of the effects to the subspecies' viability 
due to a substantial reduction in redundancy (loss of large number of 
populations from a large portion of the range). Therefore, the Lower 
Rio Grande GMU could be significant according to our definition of SPR 
under the Act.
    We next evaluated whether the Lower Rio Grande GMU is endangered or 
threatened. Our review found that there are currently 59 existing 
populations of the Rio Grande cutthroat trout in the Rio Grande 
Headwaters GMU. To assess the current status of these populations, we 
sorted each of them into four categories to consider their current 
status, which was based on effective population size, occupied stream 
length, presence of competing nonnative trout, and presence of 
hybridizing nonnative trout. We categorized 28 of the populations (47 
percent) as currently in the best or good condition (Service 2014a, pp. 
14-15). This number of populations in the best or good condition within 
this GMU provides resiliency (47 percent of populations considered 
sufficiently large to withstand stochastic events), redundancy (28 
populations in the GMU to withstand catastrophic events), and 
representation (multiple populations are persisting within the GMU to 
maintain ecological and genetic diversity).
    To consider the current risk of extinction of the Rio Grande 
cutthroat trout, we analyzed the condition of this potential SPR over 
the next 10 years to evaluate its viability (and thus its risk of 
extinction) and considered all threats with possible population-level 
effects. In 2023, we projected 43 to 51 populations will persist in the 
Lower Rio Grande GMU under our worst and best case scenarios, 
respectively (Service 2014a, p. 46). Therefore, because the worst case 
scenario forecast of the number and distribution of populations 
provides resiliency, representation, and redundancy for the subspecies 
in the Lower Rio Grande Headwaters GMU, we conclude that the subspecies 
does not meet the definition of an endangered species under the Act.
    Having found that the Rio Grande cutthroat trout is not an 
endangered species in the Lower Rio Grande GMU, we next evaluated 
whether the subspecies is a threatened species in this potential SPR. 
As with the subspecies rangewide (and for the same reasons), we used 
about 65 years from present, the year 2080, as the foreseeable future 
to consider whether the potential SPR is likely to become an endangered 
species. We also used the same rationale for future forecasting of 
persisting populations . In 2080, we projected 21 to 47 populations 
will persist in the Lower Rio Grande GMU, respectively (Service 2014a, 
p. 46). Therefore, because the worst case scenario forecast of the 
number and distribution of populations provides resiliency, 
representation, and redundancy for the subspecies in the Lower Rio 
Grande GMU, we conclude that the subspecies does not meet the 
definition of a threatened species under the Act.
    Canadian GMU--The Canadian GMU contains a small percentage of the 
existing populations: Currently 8 percent (10 of 122) of current Rio 
Grande cutthroat trout populations occur in this GMU. If this GMU were 
extirpated, there would be a decrease in overall viability of the 
subspecies, as

[[Page 59149]]

there would be if any proportion of the populations were extirpated. 
However, 112 populations would remain in the rest of the range, and the 
subspecies would still have levels of redundancy, resiliency, and 
representation for sufficient viability to persist into the future. 
Although one GMU would no longer be contributing to the representation 
of the subspecies based on ecological diversity, we are not aware of 
any particular adaptive capacity of the subspecies represented in that 
GMU. While there is unique genetic diversity within the combined 
Canadian and Pecos GMUs, the Canadian GMU independently has not been 
found to contain unique diversity. Therefore, the lower overall 
viability resulting from the potential loss of only the Canadian GMU 
would not lead the remaining portion of the subspecies' range to meet 
the definition of an endangered or threatened species under the Act. As 
such, the Canadian GMU is not found to be significant as we define SPR 
under the Act. Therefore, the subspecies is not an endangered or 
threatened species in the potential Canadian GMU SPR.
    Pecos GMU--The Pecos GMU also contains a small percentage of the 
existing populations: 10 percent (12 of 122) of current Rio Grande 
cutthroat trout populations occur in this GMU. If the Pecos GMU were 
extirpated, there would be a decrease in overall viability of the 
subspecies, as there would be if any proportion of the populations were 
extirpated. However, 110 populations would remain in the rest of the 
range, and the subspecies would still have levels of redundancy, 
resiliency, and representation for sufficient viability to persist into 
the future. Although one GMU would no longer be contributing to the 
representation of the subspecies based on ecological diversity, we are 
not aware of any particular adaptive capacity of the subspecies 
represented in that GMU. While there is unique genetic diversity within 
the combined Canadian and Pecos GMUs, the Pecos GMU independently has 
not been found to contain unique diversity. Therefore, the lower 
overall viability resulting from the potential loss of only the Pecos 
GMU would not lead the remaining portion of the subspecies' range to 
meet the definition of an endangered or threatened species under the 
Act. As such, the Pecos GMU is not significant as we define SPR under 
the Act. Therefore, the subspecies is not an endangered or threatened 
species in the potential Pecos GMU SPR.
    Pecos and Canadian GMUs Combined--The combined Pecos and Canadian 
GMUs contain a moderate percentage of the existing populations: 
Currently 18 percent (22 of 122 populations) occur in these GMUs. If 
the populations in these GMUs were to be extirpated, the loss of the 
unique genetic diversity contained collectively in these two GMUs and 
the loss of a sizable portion of the range could cause the subspecies 
in the remainder of the range to be endangered or threatened. 
Consequently, the Pecos and Canadian GMUs combined could meet the 
definition of ``significant'' under the SPR policy. Therefore, we 
evaluated whether the Rio Grande cutthroat trout is an endangered or a 
threatened species in the potential SPR of the combined Pecos and 
Canadian GMUs.
    Our review found that there are currently 22 existing populations 
of the Rio Grande cutthroat trout in the potential Pecos-Canadian SPR. 
To assess the current status of these populations, we sorted each of 
them into four categories to consider their current status, which was 
based on effective population size, occupied stream length, presence of 
competing nonnative trout, and presence of hybridizing nonnative trout. 
We categorized eight of the populations (36 percent) as currently in 
the best or good condition (Service 2014a, pp. 14-15). This number of 
populations in the best or good condition within this potential SPR 
provides resiliency (36 percent of populations considered sufficiently 
large to withstand stochastic events), redundancy (eight populations 
spread across the potential SPR to withstand catastrophic events), and 
representation (multiple populations are persisting across the 
potential SPR to maintain ecological and genetic diversity).
    To consider the current risk of extinction of the Rio Grande 
cutthroat trout, we analyzed the condition of this potential Pecos-
Canadian SPR over the next 10 years to evaluate its viability, 
considering all threats with possible population-level effects. In 
2023, we projected an estimated 19 to 30 populations will persist in 
the potential Pecos-Canadian SPR under our worst and best case 
scenarios, respectively (Service 2014a, p. 46). Therefore, because this 
worst case estimate of the number and distribution of populations 
provides resiliency, representation, and redundancy for the subspecies, 
we conclude the potential Pecos-Canadian SPR is not in danger of 
extinction and does not meet the definition of an endangered species 
under the Act.
    Having found that the Rio Grande cutthroat trout is not an 
endangered species in the potential Pecos-Canadian SPR, we next 
evaluated whether the subspecies is a threatened species in this 
potential SPR. As with the subspecies rangewide (and for the same 
reasons), we used about 65 years from present, the year 2080, as the 
foreseeable future to consider whether the potential SPR is likely to 
become an endangered species. We also used the same rationale for 
future forecasting of persisting populations as discussed above under 
the rangewide determinations. In 2080, we forecast 8 to 29 populations 
will persist in the potential Pecos-Canadian SPR under worst and best 
case scenarios, respectively (Service 2014a, p. 46). Therefore, because 
the worst case estimate of the number and distribution of populations 
provides resiliency, representation, and redundancy for the subspecies, 
we conclude the potential Pecos-Canadian SPR is not likely to be in 
danger of extinction in the foreseeable future and does not meet the 
definition of a threatened species under the Act.
    Rio Grande Headwaters and Lower Rio Grande GMUs Combined--The 
combined Rio Grande Headwaters and Lower Rio Grande GMUs contain a 
large proportion of the range: Currently 82 percent (100 of 122 
populations) occur in these GMUs. If the populations in these GMUs were 
to be extirpated, the loss of the unique genetic diversity contained 
collectively in these two GMUs and the loss of a large portion of the 
range could cause the subspecies in the remainder of the range to be 
endangered or threatened. Consequently, this potential SPR could meet 
the definition of ``significant'' under the SPR policy. Therefore, we 
evaluated whether the Rio Grande cutthroat trout is an endangered or a 
threatened species in the potential SPR of the combined Rio Grande 
Headwaters and Lower Rio Grande GMUs.
    Our review found that there are currently 100 existing populations 
of the Rio Grande cutthroat trout in the potential Rio Grande 
Headwaters-Lower Rio Grande SPR. To assess the current status of these 
populations, we sorted each of them into four categories to consider 
their current status, which was based on effective population size, 
occupied stream length, presence of competing nonnative trout, and 
presence of hybridizing nonnative trout. We categorized 47 of the 
populations (47 percent) as currently in the best or good condition 
(Service 2014a, p. 14-15). This number of populations in the best or 
good condition within this potential Rio Grande Headwaters-Lower Rio 
Grande SPR provides resiliency (47 percent of populations considered 
sufficiently large to withstand stochastic events), redundancy (47 
populations

[[Page 59150]]

spread across the potential SPR to withstand catastrophic events), and 
representation (multiple populations are persisting across the 
potential SPR to maintain ecological and genetic diversity).
    To consider the current risk of extinction of the Rio Grande 
cutthroat trout, we analyzed the condition of this potential Rio Grande 
Headwaters-Lower Rio Grande SPR over the next 10 years to evaluate its 
viability, considering all threats with possible population-level 
effects. In 2023, we forecasted 84 to 101 populations will persist in 
the potential Rio Grande Headwaters-Lower Rio Grande SPR under our 
worst and best case scenarios, respectively (Service 2014a, p. 46). 
Therefore, because the worst case scenario for the number and 
distribution of populations provides resiliency, representation, and 
redundancy for the subspecies, we conclude the potential Rio Grande 
Headwaters-Lower Rio Grande SPR is not in danger of extinction and does 
not meet the definition of an endangered species under the Act.
    Having found that the Rio Grande cutthroat trout is not an 
endangered species in the potential Rio Grande Headwaters-Lower Rio 
Grande SPR, we next evaluated whether the subspecies is a threatened 
species in this potential SPR. As with the subspecies rangewide (and 
for the same reasons), we used about 65 years from present, the year 
2080, as the foreseeable future to consider whether the potential SPR 
is likely to become endangered. We also used the same rationale for 
future forecasting of persisting populations as discussed above under 
the rangewide determinations. In 2080, we forecasted 42 to 102 
populations would persist in this potential SPR under our worst and 
best case scenarios, respectively, with multiple populations in each 
GMU (Service 2014a, p. 46). Therefore, because the worst case scenario 
for the number and distribution of populations provides resiliency, 
representation, and redundancy for the subspecies, we conclude the 
potential Rio Grande Headwaters-Lower Rio Grande SPR is not likely to 
be in danger of extinction in the foreseeable future and does not meet 
the definition of a threatened species under the Act.
Finding: Not an Endangered or a Threatened Species Based on a SPR
    We found two GMUs (Canadian and Pecos GMUs) did not meet our 
definition of significant in the SPR policy. We found four portions of 
the range that could meet our definition of significant under the SPR 
policy: Rio Grande Headwaters GMU, Lower Rio Grande GMU, Pecos and 
Canadian GMUs Combined, and Rio Grande Headwaters and Lower Rio Grande 
GMUs Combined. However, none of these portions of the range was found 
to meet the definition of an endangered or a threatened species under 
the Act. As a result, none of the potential SPR categorizations result 
in the subspecies meeting the definition of endangered or threatened 
under the Act.

Summary

    In conclusion, we find that the Rio Grande cutthroat trout is not 
in danger of extinction throughout its range, nor is it likely to 
become so in the foreseeable future. We also considered a number of 
areas concerning the potential for the subspecies to be an endangered 
or threatened species in a significant portion of its range. We found 
that four areas could meet our definition of significant; however, none 
of the potential SPRs was found to be in danger of extinction now or in 
the foreseeable future. Therefore, we determine that the Rio Grande 
cutthroat trout is not warranted for listing as an endangered or a 
threatened species under the Act throughout its rangewide or in any 
significant portion of its range.
    We request that you submit any new information concerning the 
status of, or threats to, the Rio Grande cutthroat trout to our New 
Mexico Ecological Services Field Office (see ADDRESSES) whenever it 
becomes available. New information will help us monitor the Rio Grande 
cutthroat trout and encourage its conservation. If an emergency 
situation develops for Rio Grande cutthroat trout, we will consider an 
appropriate response under the Act.

References Cited

    A complete list of references cited is available in Appendix D of 
the SSA Report (Service 2014a, Appendix D), available online at http://www.regulations.gov, under Docket Number FWS-R2-ES-2014-0042. The 
Service's PECE Evaluation (Service 2014b) is also available online at 
http://www.regulations.gov, under Docket Number FWS-R2-ES-2014-0042.

Authors

    The primary authors of this notice are the staff members of the 
Service's New Mexico Ecological Services Field Office and Southwest 
Regional Office.

Authority

    The authority for this section is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: September 23, 2014.
David Cottingham,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2014-23305 Filed 9-30-14; 8:45 am]
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