Endangered and Threatened Wildlife and Plants; Revised 12-Month Finding on a Petition To List the Upper Missouri River Distinct Population Segment of Arctic Grayling as an Endangered or Threatened Species, 49383-49422 [2014-19353]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 79, Number 161 (Wednesday, August 20, 2014)]
[Proposed Rules]
[Pages 49383-49422]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-19353]



[[Page 49383]]

Vol. 79

Wednesday,

No. 161

August 20, 2014

Part II





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Revised 12-Month Finding 
on a Petition To List the Upper Missouri River Distinct Population 
Segment of Arctic Grayling as an Endangered or Threatened Species; 
Proposed Rule

Federal Register / Vol. 79 , No. 161 / Wednesday, August 20, 2014 / 
Proposed Rules

[[Page 49384]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2013-0120; 4500030113]


Endangered and Threatened Wildlife and Plants; Revised 12-Month 
Finding on a Petition To List the Upper Missouri River Distinct 
Population Segment of Arctic Grayling 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 
revised 12-month finding on a petition to list the Upper Missouri River 
distinct population segment (Upper Missouri River DPS) of Arctic 
grayling (Thymallus arcticus) 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 Upper Missouri River DPS of Arctic grayling is 
not warranted at this time. The best available scientific and 
commercial information indicates that habitat-related threats 
previously identified, including habitat fragmentation, dewatering, 
thermal stress, entrainment, riparian habitat loss, and effects from 
climate change, for the Upper Missouri River DPS of Arctic grayling 
have been sufficiently ameliorated and that 19 of 20 populations of 
Arctic grayling are either stable or increasing. This action removes 
the Upper Missouri River DPS of the Arctic grayling from our candidate 
list. Although listing is not warranted at this time, we ask the public 
to submit to us any new information that becomes available concerning 
the threats to the Upper Missouri River DPS of Arctic grayling or its 
habitat at any time.

DATES: The finding announced in this document was made on August 20, 
2014.

ADDRESSES: This finding is available on the Internet at https://www.regulations.gov at Docket Number FWS-R6-ES-2013-0120. 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, Montana Ecological Services Office, 585 
Shepard Way, Suite 1, Helena, MT 59601. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above street address.

FOR FURTHER INFORMATION CONTACT: Jodi Bush, Field Supervisor, Montana 
Ecological Services Office (see ADDRESSES); telephone 406-449-5225. If 
you use a telecommunications device for the deaf (TDD), please call the 
Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires 
that, for any petition to revise the 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. We must publish these 12-month findings 
in the Federal Register.

Previous Federal Actions

    We have published a number of documents on Arctic grayling since 
1982, and have been involved in litigation over previous findings. We 
describe previous federal actions that are relevant to this document 
below.
    We published our first status review for the Montana Arctic 
grayling (Thymallus arcticus montanus), then thought to be a subspecies 
of Arctic grayling, in a Federal Register document on December 30, 1982 
(47 FR 58454). In that document, we designated the purported 
subspecies, Montana Arctic grayling, as a Category 2 species. At that 
time, we designated a species as Category 2 if a listing as endangered 
or threatened was possibly appropriate, but we did not have sufficient 
data to support a proposed rule to list the species.
    On October 9, 1991, the Biodiversity Legal Foundation and George 
Wuerthner petitioned us to list the fluvial (riverine) populations of 
Arctic grayling in the Upper Missouri River basin as an endangered 
species throughout its historical range in the coterminous United 
States. We published a notice of a 90-day finding in the January 19, 
1993, Federal Register (58 FR 4975), concluding the petitioners 
presented substantial information indicating that listing the fluvial 
Arctic grayling of the Upper Missouri River in Montana and northwestern 
Wyoming may be warranted. This finding also noted that taxonomic 
recognition of the Montana Arctic grayling (Thymallus arcticus 
montanus) as a subspecies (previously designated as a category 2 
species) was not widely accepted, and that the scientific community 
generally considered this population a geographically isolated member 
of the wider species (T. arcticus).
    On July 25, 1994, we published notification of a 12-month finding 
in the Federal Register (59 FR 37738), concluding that listing the DPS 
of fluvial Arctic grayling in the Upper Missouri River was warranted 
but precluded by other higher priority listing actions. This DPS 
determination predated our DPS policy (61 FR 4722, February 7, 1996), 
so the entity did not undergo a DPS analysis as described in the 
policy. The 1994 finding placed fluvial Arctic grayling of the Upper 
Missouri River on the candidate list and assigned it a listing priority 
of 9, indicating that the threats were imminent but of moderate to low 
magnitude.
    On May 31, 2003, the Center for Biological Diversity and Western 
Watersheds Project (Plaintiffs) filed a complaint in U.S. District 
Court in Washington, DC, challenging our 1994 ``warranted but 
precluded'' determination for the DPS of fluvial Arctic grayling in the 
Upper Missouri River basin. On May 4, 2004, we elevated the listing 
priority number of the fluvial Arctic grayling to 3 (69 FR 24881), 
indicating threats that were imminent and of high magnitude. On July 
22, 2004, the Plaintiffs amended their complaint to challenge our 
failure to emergency list this population. We settled with the 
Plaintiffs in August 2005, and we agreed to submit a revised 
determination on whether this population warranted listing as 
endangered or threatened to the Federal Register on or before April 16, 
2007.
    On April 24, 2007, we published a revised 12-month finding on the 
petition to list the Upper Missouri River DPS of fluvial Arctic 
grayling (72 FR 20305) (``2007 finding''). In this finding, we 
determined that fluvial Arctic grayling of the upper Missouri River did 
not constitute a species, subspecies, or DPS under the Act. Therefore, 
we found that the upper Missouri River

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population of fluvial Arctic grayling was not a listable entity under 
the Act, and, as a result, listing was not warranted. With that 
document, we withdrew the fluvial Arctic grayling from our candidate 
list.
    On November 15, 2007, the Center for Biological Diversity, 
Federation of Fly Fishers, Western Watersheds Project, George 
Wuerthner, and Pat Munday filed a complaint (CV-07-152, in the District 
Court of Montana) to challenge our 2007 finding. We settled this 
litigation on October 5, 2009. In the stipulated settlement, we agreed 
to: (a) Publish, on or before December 31, 2009, a document in the 
Federal Register soliciting information on the status of the upper 
Missouri River Arctic grayling; and (b) submit, on or before August 30, 
2010, a new 12-month finding for the upper Missouri River Arctic 
grayling to the Federal Register.
    On October 28, 2009, we published in the Federal Register a notice 
of intent to conduct a status review of Arctic grayling (Thymallus 
arcticus) in the upper Missouri River system (74 FR 55524). To ensure 
the status review was based on the best available scientific and 
commercial data, we requested information on the taxonomy, biology, 
ecology, genetics, and population status of the Arctic grayling of the 
upper Missouri River system; information relevant to consideration of 
the potential DPS status of Arctic grayling of the upper Missouri River 
system; threats to the species; and conservation actions being 
implemented to reduce those threats in the upper Missouri River system. 
That document further specified that the status review might consider 
various DPS designations that include different life histories of 
Arctic grayling in the upper Missouri River system and different DPS 
configurations, including fluvial, adfluvial (lake populations), or all 
life histories of Arctic grayling in the upper Missouri River system.
    On September 8, 2010, we published a revised 12-month finding on 
the petition to list the Upper Missouri River DPS of Arctic grayling 
(75 FR 54708) (``2010 finding''). In this finding, we determined that 
fluvial and adfluvial Arctic grayling of the upper Missouri River did 
constitute a DPS under the Act. Further, we found that a DPS 
configuration including both adfluvial and fluvial life histories was 
the most appropriate for the long-term conservation of Arctic grayling 
because genetic evidence indicated that fluvial and adfluvial life-
history forms did not represent distinct evolutionary lineages. We 
concluded by finding that the Upper Missouri River DPS of Arctic 
grayling was warranted for listing under the Act, but precluded by 
other higher priority listing actions.
    On September 9, 2011, we reached an agreement with plaintiffs in 
Endangered Species Act Section 4 Deadline Litig., Misc. Action No. 10-
377 (EGS), MDL Docket No. 2165 (D. D.C.) (known as the ``MDL case'') on 
a schedule to publish proposed listing rules or not-warranted findings 
for the species on our candidate list. This agreement stipulated that 
we would submit for publication in the Federal Register either a 
proposed listing rule for the Upper Missouri River DPS of Arctic 
grayling, or a not-warranted finding, no later than the end of Fiscal 
Year 2014.
    On November 26, 2013, we published a document in the Federal 
Register (78 FR 70525) notifying the public that we were initiating a 
status review of the Upper Missouri River DPS of Arctic grayling to 
determine whether the entity meets the definition of an endangered or 
threatened species under the Act. That document requested general 
information (taxonomy, biology, ecology, genetics, and status) on the 
Arctic grayling of the upper Missouri River system, as well as 
information on the conservation status of, threats to, planned and 
ongoing conservation actions for, habitat selection of, habitat 
requirements of, and considerations concerning the possible designation 
of critical habitat for the Arctic grayling of the upper Missouri River 
system.
    This document constitutes a revised 12-month finding (``2014 
finding'') on whether to list the Upper Missouri River DPS of Arctic 
grayling (Thymallus arcticus) as endangered or threatened under the 
Act, and fulfills our commitments under the MDL case.

Species Information

Taxonomy and Species Description
    The Arctic grayling (Thymallus arcticus) is a fish belonging to the 
family Salmonidae (salmon, trout, charr, whitefishes), subfamily 
Thymallinae (graylings), and it is represented by a single genus, 
Thymallus. Arctic grayling have elongate, laterally compressed, trout-
like bodies with deeply forked tails, and adults typically average 300-
380 millimeters (mm) (12-15 inches (in.)) in length. Coloration can be 
striking, and varies from silvery or iridescent blue and lavender, to 
dark blue (Behnke 2002, pp. 327-328). A prominent morphological feature 
of Arctic grayling is the sail-like dorsal fin, which is large and 
vividly colored with rows of orange to bright green spots, and often 
has an orange border (Behnke 2002, pp. 327-328).
    For more detail on taxonomy and species description, see the 2010 
finding (75 FR 54708).
Distribution
    Arctic grayling are native to Arctic Ocean drainages of Alaska and 
northwestern Canada, as far east as Hudson's Bay, and westward across 
northern Eurasia to the Ural Mountains (Scott and Crossman 1998, pp. 
301-302; Froufe et al. 2005, pp. 106-107; Weiss et al. 2006, pp. 511-
512). In North America, they are native to northern Pacific Ocean 
drainages as far south as the Stikine River in British Columbia (Nelson 
and Paetz 1991, pp. 253-256; Behnke 2002, pp. 327-331).
    For a full discussion on the global distribution of Arctic 
grayling, see the 2010 finding (75 FR 54709-54710). Here, we focus on 
the distribution of Arctic grayling within the conterminous United 
States.
Distribution in the Conterminous United States
    Two disjunct groups of Arctic grayling were native to the 
conterminous United States: One in the upper Missouri River basin in 
Montana and Wyoming (currently extant only in Montana); and another in 
Michigan that was extirpated in the late 1930s (Hubbs and Lagler 1949, 
p. 44), and has not been detected since.
    During the status review process, the Service received information 
indicating that Arctic grayling may have also been native to areas 
outside the Upper Missouri River basin in Montana and Wyoming. This 
information included multiple historical newspaper clippings and 
several reports from early Army expeditions purporting that Arctic 
grayling were captured in the Yellowstone River drainage in Montana and 
the Snake River drainage in Idaho (Shea 2014, entire). Some of these 
reports even included descriptions of captured fish. However, none of 
the descriptions mentions the colorful, sail-like dorsal fin of Arctic 
grayling, a prominent feature that clearly distinguishes Arctic 
grayling from other salmonids. In addition, a similar species 
resembling Arctic grayling (i.e., mountain whitefish) is native to both 
the Yellowstone River drainage and Snake River drainage. Mountain 
whitefish were sometimes referred to as ``grayling'' in some areas of 
the West (Ellis 1914, p. 75). Thus, it is likely that early reports of 
Arctic grayling occurring outside the upper Missouri River basin were 
mountain whitefish misidentified as Arctic grayling. Therefore, without 
information to the contrary, we consider Arctic grayling to

[[Page 49386]]

be native only to the upper Missouri River basin in Montana and Wyoming 
and to Michigan.
Native Distribution of Arctic Grayling in the Upper Missouri River 
Basin
    The first Euro-American ``discovery'' of Arctic grayling in North 
America is attributed to members of the Lewis and Clark Expedition, who 
encountered the species in the Beaverhead River in August 1805 (Nell 
and Taylor 1996, p. 133). Vincent (1962, p. 11) and Kaya (1992, pp. 47-
51) synthesized accounts of Arctic grayling occurrence and abundance 
from historical surveys and contemporary monitoring to determine the 
historical distribution of the species in the upper Missouri River 
system (Figure 1). We base our conclusions on the historical 
distribution of Arctic grayling in the upper Missouri River basin on 
these two reviews. Arctic grayling were widely but irregularly 
distributed in the upper Missouri River system above the Great Falls in 
Montana and in northwest Wyoming within the present-day location of 
Yellowstone National Park (Vincent 1962, p. 11). They were estimated to 
inhabit up to 2,000 kilometers (km) (1,250 miles (mi)) of stream 
habitat until the early 20th century (Kaya 1992, pp. 47-51). Arctic 
grayling were reported in the mainstem Missouri River, as well as in 
the Smith, Sun, Jefferson, Madison, Gallatin, Big Hole, Beaverhead, and 
Red Rock Rivers (Vincent 1962, p. 11; Kaya 1992, pp. 47-51; USFWS 2007; 
72 FR 20307, April 24, 2007). Anecdotal accounts report that the 
species may have been present in the Ruby River, at least seasonally 
(Magee 2005, pers. comm.), and were observed there as recently as the 
early 1970s (Holton, undated).
BILLING CODE 4310-55-P

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[GRAPHIC] [TIFF OMITTED] TP20AU14.000

BILLING CODE 4310-55-C
    Fluvial Arctic grayling were historically widely distributed in the 
upper Missouri River basin, but a few adfluvial populations also were 
native to the basin. For example, Arctic grayling are native to Red 
Rock Lakes, in the Centennial Valley (Vincent 1962, pp. 112-121; Kaya 
1992, p. 47). Vincent (1962, p. 120) stated that Red Rock Lakes were 
the only natural lakes in the upper Missouri River basin accessible to 
colonization by Arctic grayling, and concluded that Arctic grayling 
there were the only native adfluvial population in the basin. However, 
Arctic grayling were also native to Elk Lake (in the Centennial Valley; 
Kaya 1990, p. 44) and a few small lakes in the upper Big Hole River 
drainage, based on recent genetic information (Peterson and Ardren 
2009, p. 1768).
    The distribution of native Arctic grayling in the upper Missouri 
River went through a dramatic reduction in the first 50 years of the 
20th century, especially in riverine habitats (Vincent 1962, pp. 86-90, 
97-122, 127-129; Kaya 1992, pp. 47-53). The native populations that 
formerly resided in the

[[Page 49388]]

Smith, Sun, Jefferson, Beaverhead, Gallatin, and mainstem Missouri 
Rivers are considered extirpated, and the only remaining native fluvial 
population is found in the Big Hole River and some of its tributaries 
(Kaya 1992, pp. 51-53). The fluvial form currently occupies less than 
10 percent of its historical range in the Missouri River system (Kaya 
1992, p. 51). Other native populations in the upper Missouri River 
occur in two small, headwater lakes in the upper Big Hole River system 
(Miner and Mussigbrod Lakes); the upper Ruby River (recently 
reintroduced from Big Hole River stock); the Madison River upstream 
from Ennis Reservoir; Elk Lake in the Centennial Valley (recently 
reintroduced from Red Rock Lakes stock); and the Red Rock Lakes in the 
Centennial Valley (Everett 1986, p. 7; Kaya 1992, p. 53; Peterson and 
Ardren 2009, pp. 1762, 1768; see Figure 1).
Introduced Lake-Dwelling Arctic Grayling in the Upper Missouri River 
Basin
    From 1898 through the 1960s, an estimated 100 million Arctic 
grayling were stocked across Montana and other western States. The 
sources of these stockings varied through time as different State, 
Federal, and private hatchery operations were created, but the ultimate 
source for all hatcheries in Montana appears to be stock from two 
Montana populations: Centennial Valley and Madison River (Peterson and 
Ardren 2009, p. 1767; Leary 2014, unpublished data; MFISH 2014a). 
Arctic grayling derived from these two sources were stocked on top of 
every known native Arctic grayling population in the upper Missouri 
River basin. In addition, Arctic grayling were stocked in multiple high 
elevation lakes, some of which likely were historically fishless.
    There are 20 known, introduced Arctic grayling populations that 
exist in the upper Missouri River basin. These 20 populations, along 
with the 6 populations existing in native habitat, comprise the 
listable entity (total of 26 populations) of Arctic grayling in the 
upper Missouri River basin. However, six of these introduced 
populations are considered to have low conservation value because they 
occupy unnatural habitat, are not self-sustaining, or are used as 
captive brood reserves. These six populations are Axolotl Lake, Green 
Hollow Lake, Sunnyslope Canal, Tunnel Lake, South Fork Sun River, and 
Elk Lake. The Axolotl and Green Hollow populations are captive brood 
reserves maintained in natural lakes for reintroduction purposes. 
Sunnyslope Canal is a fluvial population that occurs in unnatural 
habitat (irrigation canal). Tunnel Lake is stocked with ``rescued'' 
fish from Sunnyslope Canal, but lacks a spawning tributary and is 
consequently not self-sustaining (SSA 2014). South Fork Sun River is a 
small fluvial population that resides in about \1/4\ mile of stream 
during the summer and is not considered self-sustaining (SSA 2014). The 
Elk Lake population is a genetic replicate of the Centennial Valley 
population, but no documented spawning has occurred to date (Jaeger 
2014a, pers. comm.); thus this population is not currently considered 
self-sustaining. For these reasons, we primarily focus our analysis on 
the populations considered to have high conservation value; those 
populations that are self-sustaining, in natural habitats, and wild.
    The 14 known remaining introduced, lake-dwelling (adfluvial) Arctic 
grayling populations within the upper Missouri River basin are likely 
the result of historical stocking (Table 1). In our 2010 finding, we 
considered and discussed the conservation value of these populations. 
Based on the information available at that time, we considered these 
introduced populations to not have conservation value for multiple 
reasons. Below, we list each of the reasons for this conclusion as 
provided in the 2010 finding, and provide an updated assessment and 
conclusion about the potential conservation value of these populations, 
based on new information obtained since 2010.

Table 1--Geographic Distribution, Genetic Status, and Source of Introduced Adfluvial Arctic Grayling Populations
                                        in the Upper Missouri River Basin
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                                                    Genetic
          Population               Drainage         analysis        Source \a\               Citation
                                                   completed?
----------------------------------------------------------------------------------------------------------------
Agnes Lake...................  Big Hole.......  No.............  Madison/         MFISH 2014a.
                                                                  Centennial.
Odell Lake...................  Big Hole.......  Yes............  Centennial.....  Peterson and Ardren 2009, p.
                                                                                   1766; Leary 2014, unpublished
                                                                                   data.
Bobcat Lake..................  Big Hole.......  Yes............  Centennial.....  Peterson and Ardren 2009, p.
                                                                                   1766; Leary 2014, unpublished
                                                                                   data.
Schwinegar Lake..............  Big Hole.......  No.............  Madison/         ..............................
                                                                  Centennial.\c\.
Pintlar Lake.................  Big Hole.......  Yes............  Madison/         Leary 2014, unpublished data.
                                                                  Centennial.
Deer Lake....................  Gallatin.......  Yes............  Madison/         Leary 2014, unpublished data.
                                                                  Centennial.
Emerald Lake.................  Gallatin.......  Yes............  Madison/         Leary 2014, unpublished data.
                                                                  Centennial.
Grayling Lake................  Gallatin.......  Yes............  Madison/         Leary 2014, unpublished data.
                                                                  Centennial.
Hyalite Lake.................  Gallatin.......  Yes............  Madison/         Leary 2014, unpublished data.
                                                                  Centennial.
Diversion Lake...............  Sun............  Yes \b\........  Big Hole.......  Horton 2014a, pers. comm.;
                                                                                   Magee 2014, pers. comm.
Gibson Reservoir.............  Sun............  Yes \b\........  Big Hole.......  Horton 2014a, pers. comm.;
                                                                                   Magee 2014, pers. comm.
Lake Levale..................  Sun............  Yes \b\........  Big Hole.......  Horton 2014a, pers. comm.;
                                                                                   Magee 2014, pers. comm.
Park Lake....................  Missouri.......  No.............  Madison/         ..............................
                                                                  Centennial.\c\.
Grebe Lake...................  Madison........  Yes............  Centennial.....  Peterson and Ardren 2009, p.
                                                                                   1766; Varley 1981, p. 11.
----------------------------------------------------------------------------------------------------------------
\a\ Origin of source stock was determined by genetic analysis and through analysis of historical stocking
  records and scientific literature, in some cases. Where multiple sources are cited, fish from each population
  were known to be stocked, although the genetic contribution of each donor population to the current population
  structure is unknown.
\b\ These populations are the result of reintroductions using known sources of Montana origin.
\c\ Schwinegar and Park Lakes Arctic grayling populations are likely from Montana-origin sources due to
  proximity to other lakes with known Montana origin; however, definitive evidence is lacking.

    1. The Service interprets the Act to provide a statutory directive 
to conserve species in their native ecosystems (49 FR 33885, August 27, 
1984) and to conserve genetic resources and biodiversity over a 
representative portion of a taxon's historical occurrence (61 FR 4722, 
February 7, 1996). Since most of the introduced populations of Arctic 
grayling were of unknown genetic origin and in lakes that were likely 
historically fishless,

[[Page 49389]]

these populations were considered in 2010 to be outside the species' 
native range, and we concluded that they did not appear to add 
conservation value to the DPS.
    Since 2010, new genetic information from 7 of the 14 introduced 
populations indicates there are moderate to high levels of genetic 
diversity within and among these populations, and indicates these 
populations were derived from native sources within the upper Missouri 
River basin (Leary 2014, unpublished data; Table 1). In addition, 
stocking records show common stocking sources for introduced 
populations that were genotyped (as described previously) and the two 
populations that were not genotyped (the remaining 3 populations were 
reintroductions of known Montana origin sources; Table 1). Thus, it 
appears that all 14 introduced Arctic grayling populations contain 
moderate to high levels of genetic diversity of Arctic grayling in the 
upper Missouri River basin that was not captured within the DPS 
designation in the 2010 finding.
    The Service's current interpretation of the Act is consistent with 
that in the 2010 finding; we believe it is important to conserve 
species in their native ecosystems and to conserve genetic resources 
and biodiversity over a representative portion of a taxon's historical 
occurrence. In light of the new genetics information gained since 2010 
(Leary 2014, unpublished data), we also believe it is important to 
acknowledge the moderate to high levels of genetic diversity within the 
introduced populations in the upper Missouri River basin and the 
potential adaptive capabilities represented by this diversity. All 
Arctic grayling populations (introduced or not) currently within the 
upper Missouri River basin are derived from a common ancestor and have 
a distinct evolutionary trajectory relative to the historical founding 
populations in Canada and Alaska. Thus, Arctic grayling originating 
from and currently within the upper Missouri River basin represent the 
southernmost assemblage of the species, facing similar selection 
pressures and evolving independent of more northern populations.
    The introduced Arctic grayling populations in the upper Missouri 
River basin occupy, for the most part, high-elevation habitats that are 
high-quality because of intact riparian areas and a consistent supply 
of cool water. Given the predicted effects of climate change in the 
West (see discussion under ``Climate Change'' in Factor A below), these 
types of habitats are the same habitats that the Service would explore 
for long-term conservation of Arctic grayling, if needed, because they 
may serve as thermal refugia as temperatures rise and provide greater 
redundancy in case of catastrophic events.
    2. In 2010, the Service concluded there did not appear to be any 
formally recognized conservation value for the introduced populations 
of Arctic grayling in the upper Missouri River basin because they were 
not being used in conservation or restoration programs. This conclusion 
was based on an interpretation of a National Marine Fisheries Service 
final policy on the consideration of hatchery-origin fish in Endangered 
Species Act listing determinations for Pacific salmon and steelhead 
(anadromous Oncorhynchus spp.) (NMFS 2005, entire).
    Until recently, the genetic structure and source of these 
introduced populations were unknown. Populations with a high likelihood 
of being Montana origin were used for conservation purposes (e.g., 
reintroductions) as a precautionary approach to Arctic grayling 
conservation. Now that the amount of genetic diversity within and among 
the introduced Arctic grayling populations and their source(s) are 
known, it is probable these introduced populations could be used in 
future conservation actions as source stock, if needed.
    3. In 2010, the Service indicated there were concerns that 
introduced, lake-dwelling Arctic grayling populations could pose 
genetic risks to the native fluvial population (i.e., Big Hole 
Population) as cited in the Montana Fluvial Arctic Grayling Restoration 
Plan (``Restoration Plan,'' 1995, p. 15). In the Restoration Plan, 
Arctic grayling populations in Agnes, Schwinegar, Odell, Miner and 
Mussigbrod lakes were identified as potential threats to the genetic 
integrity of the Big Hole River population because of hydrologic 
connectivity between these lakes and the Big Hole River and the 
potential for genetic mixing.
    Recently, genetic analyses have confirmed reproductive isolation 
among extant Arctic grayling populations in the upper Missouri River 
basin and within the Big Hole River watershed (Peterson and Ardren 
2009, p. 1770; Leary 2014, unpublished data). In addition, multiple 
historical stockings have occurred in the Big Hole River from other 
sources within the upper Missouri River basin. Recent genetic analysis 
found no evidence of a significant genetic contribution from historical 
stocking on the current genetic structure of Arctic grayling in the Big 
Hole River (Peterson and Ardren 2009, p. 1768). Thus, we now conclude 
that the concern that lake-dwelling populations within the Big Hole 
River watershed could pose genetic risks to the Big Hole River fluvial 
population appears unfounded.
    4. In 2010, the Service concluded that introduced populations of 
Arctic grayling in the upper Missouri River basin had no conservation 
value because these populations apparently had been isolated from their 
original source stock for decades without any supplementation from the 
wild and were established without any formal genetic consideration to 
selecting and mating broodstock.
    It is now apparent from our review of historical stocking records 
that many of these introduced populations received multiple stockings 
from the same source or multiple stockings from several different 
sources over a wide range of years (MFISH 2014a, unpublished data). 
Additionally, most individual stockings involved a large number of eggs 
or fry (up to 1 million for some stockings). Cumulatively, this 
information suggests several points. First, stockings that used a large 
number of eggs or fry necessitate that gametes from multiple brood fish 
were used per stocking, given the physical constraints of number of 
eggs per unit body size of female Arctic grayling. Second, stockings in 
most of the introduced populations occurred over many years (up to 60 
years in some cases). This indicates different cohorts of Arctic 
grayling had to be used, since the generation time of Arctic grayling 
is approximately 3.5 years in the upper Missouri River basin 
(references in Dehaan et al. 2014, p. 10). Lastly, the new genetic 
analyses from seven of the introduced Arctic grayling populations 
indicate moderate to high levels of genetic diversity within the 
populations. This result could likely only be obtained from the 
founding of these populations using large numbers of brood fish and 
gametes over multiple years. Mutation is unlikely to have accounted for 
these levels of genetic diversity over a relatively short time period 
of isolation (Freeman and Herron 2001, p. 143).
    For perspective, Montana Fish, Wildlife, and Parks has developed 
guidelines for the establishment and maintenance of Arctic grayling 
broodstock. To adequately capture most of the genetic variation in a 
source population, the crossing of a minimum of 25 male and 25 female 
Arctic grayling is currently recommended (Leary 1991, p. 2151). It is 
likely that the historical stockings used to found the introduced 
Arctic grayling populations in the upper Missouri River basin equaled 
or exceeded this through stocking large

[[Page 49390]]

numbers of eggs or fry over multiple years.
    5. In 2010, the Service concluded that the source populations used 
to found the introduced Arctic grayling populations in the upper 
Missouri River drainage were not well documented (Peterson and Ardren 
2009, p. 1767), so we could not be certain of whether these Arctic 
grayling were of local origin.
    Since 2010, new genetic information (Leary 2014, unpublished data) 
and review of historical stocking records (MFISH 2014a, unpublished 
data) indicate the founding populations used for stocking are local and 
believed representative of the Upper Missouri River DPS of Arctic 
grayling, and contain moderate to high levels of genetic diversity.
    6. In 2010, the Service concluded the primary intent of culturing 
and introducing Arctic grayling populations within the upper Missouri 
River basin was to provide recreational fishing opportunities in high 
mountain lakes, and that, therefore, these introduced populations had 
no conservation value.
    Since 2010, review of the historical literature indicates adfluvial 
Arctic grayling populations were presumably stocked both for 
recreational fishing and conservation purposes (Brown 1943, pp. 26-27; 
Nelson 1954, p. 341; Vincent 1962, p. 151). Following the drought in 
the 1930s, conservation stockings of Arctic grayling were advocated 
because most rivers and streams were dewatered, prompting fish managers 
to introduce Arctic grayling into habitats with a more consistent 
supply of cool water (e.g., high-elevation mountain lakes; Brown 1943, 
pp. 26-27; Nelson 1954, p. 341; Vincent 1962, p. 151).
    In conclusion, introduced populations of Arctic grayling 
established within the upper Missouri River basin, whether they were 
originally established for recreational fishing or conservation 
purposes, captured moderate to high levels of genetic diversity of 
upper Missouri River basin Arctic grayling. The potential adaptive 
capabilities represented by this genetic diversity have conservation 
value, particularly in a changing climate. These populations reside in 
high-quality habitat, the same habitat the Service would look to for 
long-term conservation, if needed. Thus, the introduced populations of 
Arctic grayling within the upper Missouri River basin have conservation 
value, and, therefore, we include them in our analysis of a potential 
DPS of Arctic grayling.
Origins, Biogeography, and Genetics of Arctic Grayling in North America
    North American Arctic grayling are most likely descended from 
Eurasian Thymallus that crossed the Bering land bridge during or before 
the Pleistocene glacial period (Stamford and Taylor 2004, pp. 1533, 
1546). There were multiple opportunities for freshwater faunal exchange 
between North America and Asia during the Pleistocene, but genetic 
divergence between North American and Eurasian Arctic grayling suggests 
that the species could have colonized North America as early as the 
mid-late Pliocene (more than 3 million years ago) (Stamford and Taylor 
2004, p. 1546). Genetic studies of Arctic grayling using mitochondrial 
DNA (mtDNA, maternally inherited DNA located in cellular organelles 
called mitochondria) and microsatellite DNA (repeating sequences of 
nuclear DNA) have shown that North American Arctic grayling consist of 
at least three major lineages that originated in distinct Pleistocene 
glacial refugia (Stamford and Taylor 2004, p. 1533). These three groups 
include a South Beringia lineage found in western Alaska to northern 
British Columbia, Canada; a North Beringia lineage found on the North 
Slope of Alaska, the lower Mackenzie River, and to eastern 
Saskatchewan; and a Nahanni lineage found in the lower Liard River and 
the upper Mackenzie River drainage in northeastern British Columbia and 
southeastern Yukon (Stamford and Taylor 2004, pp. 1533, 1540). Arctic 
grayling from the upper Missouri River basin were tentatively placed in 
the North Beringia lineage because a small sample (three individuals) 
of Montana Arctic grayling shared a mtDNA haplotype (form of the mtDNA) 
with populations in Saskatchewan and the lower Peace River, British 
Columbia (Stamford and Taylor 2004, p. 1538).
    The existing mtDNA data suggest that Missouri River Arctic grayling 
share a common ancestry with the North Beringia lineage, but other 
genetic markers (e.g., allozymes, microsatellites) and biogeographic 
history indicate that Missouri River Arctic grayling have been 
physically and reproductively isolated from northern populations for 
millennia. Pre-glacial colonization of the Missouri River basin by 
Arctic grayling was possible because the river flowed to the north and 
drained into the Arctic-Hudson Bay prior to the last glacial cycle 
(Cross et al. 1986, pp. 374-375; Pielou 1991, pp. 194-195). Low mtDNA 
diversity observed in a small number of Montana Arctic grayling samples 
and a shared ancestry with Arctic grayling from the North Beringia 
lineage suggest a more recent, post-glacial colonization of the upper 
Missouri River basin. In contrast, microsatellite DNA show substantial 
divergence between Montana and Saskatchewan (i.e., same putative mtDNA 
lineage) (Peterson and Ardren 2009, entire). Differences in the 
frequency and size distribution of microsatellite alleles between 
Montana populations and two Saskatchewan populations indicate that 
Montana Arctic grayling have been isolated long enough for mutations 
(i.e., evolution) to be responsible for the observed genetic 
differences.
    Additional comparison of 21 Arctic grayling populations from 
Alaska, Canada, and the Missouri River basin using 9 of the same 
microsatellite loci as Peterson and Ardren (2009, entire) further 
supports the distinction of Missouri River Arctic grayling relative to 
populations elsewhere in North America (USFWS, unpublished data). 
Analyses of these data using two different methods clearly separates 
sample fish from 21 populations into two clusters: One cluster 
representing populations from the upper Missouri River basin, and 
another cluster representing populations from Canada and Alaska (USFWS, 
unpublished data). These new data, although not yet peer reviewed, 
support the interpretation that the previous analyses of Stamford and 
Taylor (2004, entire) underestimated the distinctiveness of Missouri 
River Arctic grayling relative to other sample populations, likely 
because of the combined effect of small sample sizes and the lack of 
variation observed in the Missouri River for the markers used in that 
study (Stamford and Taylor 2004, pp. 1537-1538). Thus, these recent 
microsatellite DNA data suggest that Arctic grayling may have colonized 
the Missouri River before the onset of Wisconsin glaciation (more than 
80,000 years ago).
    Genetic relationships among native and introduced populations of 
Arctic grayling in Montana have recently been investigated (Peterson 
and Ardren 2009, entire). Introduced, lake-dwelling populations of 
Arctic grayling trace some of their original ancestry to the Centennial 
Valley (Peterson and Ardren 2009, p. 1767), and stocking of hatchery 
Arctic grayling did not have a large effect on the genetic composition 
of the extant native populations (Peterson and Ardren 2009, p. 1768). 
Differences between native populations of the two Arctic grayling 
ecotypes (adfluvial, fluvial) are not as large as differences resulting 
from geography (i.e., drainage of origin). For example, native 
adfluvial Arctic grayling populations from

[[Page 49391]]

different lakes are genetically different (Peterson and Ardren 2009, p. 
1766).
Habitat
    Arctic grayling generally require clear, cold water, and are 
characterized as belonging to a ``coldwater'' group of salmonids, which 
also includes bull trout (Salvelinus confluentus) and Arctic char 
(Salvelinus alpinus) (Selong et al. 2001, p. 1032). Arctic grayling 
optimal thermal habitat is between 7 to 17 [deg]C (45 to 63 [deg]F), 
but becomes unsuitable above 20 [deg]C (68 [deg]F) (Hubert et al. 1985, 
p. 24). Arctic grayling fry may be more tolerant of high water 
temperature than adults (LaPerriere and Carlson 1973, p. 30; Feldmeth 
and Eriksen 1978, p. 2041).
    Having a broad, nearly circumpolar distribution, Arctic grayling 
occupy a variety of habitats including small streams, large rivers, 
lakes, and even bogs (Northcote 1995, pp. 152-153; Scott and Crossman 
1998, p. 303). They may even enter brackish water (less than or equal 
to 4 parts per thousand salt content) when migrating between adjacent 
river systems (West et al. 1992, pp. 713-714). Native populations are 
found at elevations ranging from near sea level, such as in Bristol 
Bay, Alaska, to high-elevation montane valleys (more than 1,830 meters 
(m) or 6,000 feet (ft)), such as the Big Hole River and Centennial 
Valley in southwestern Montana. Despite this broad distribution, Arctic 
grayling have specific habitat requirements that can constrain their 
local distributions, especially water temperature and channel gradient. 
At the local scale, Arctic grayling prefer cold water and are often 
associated with spring-fed habitats in regions with warmer climates 
(Vincent 1962, p. 33). Arctic grayling are generally not found in 
swift, high-gradient streams, and Vincent (1962, pp. 36-37, 41-43) 
characterized typical Arctic grayling habitat in Montana (and Michigan) 
as low-to-moderate gradient (less than 4 percent) streams and rivers 
with low-to-moderate water velocities (less than 2 feet/sec (60 
centimeters/sec)). Juvenile and adult Arctic grayling in streams and 
rivers spend much of their time in pool habitat (Kaya 1990 and 
references therein, p. 20; Lamothe and Magee 2003, pp. 13-14).
Breeding
    Arctic grayling typically spawn in the spring or early summer, 
depending on latitude and elevation (Northcote 1995, p. 149). In 
Montana, Arctic grayling generally spawn from late April to mid-May by 
depositing adhesive eggs over gravel substrate without excavating a 
nest (Kaya 1990, p. 13; Northcote 1995, p. 151). In general, the 
reproductive ecology of Arctic grayling differs from other salmonid 
species (trout and salmon) in that Arctic grayling eggs tend to be 
comparatively small; thus, they have higher relative fecundity (females 
have more eggs per unit body size). Males establish and defend spawning 
territories rather than defending access to females (Northcote 1995, 
pp. 146, 150-151). The time required for development of eggs from 
embryo until they emerge from stream gravel and become swim-up fry 
depends on water temperature (Northcote 1995, p. 151). In the upper 
Missouri River basin, development from embryo to fry averages about 3 
weeks (Kaya 1990, pp. 16-17). Small, weakly swimming fry (typically 1-
1.5 centimeters (cm) (0.4-0.6 in.) at emergence) prefer low-velocity 
stream habitats (Armstrong 1986, p. 6; Kaya 1990, pp. 23-24; Northcote 
1995, p. 151).
    Arctic grayling of all ages feed primarily on aquatic and 
terrestrial invertebrates captured on or near the water surface, but 
also will feed opportunistically on fish and fish eggs (Northcote 1995, 
pp. 153-154; Behnke 2002, p. 328). Feeding locations for individual 
fish are typically established and maintained through size-mediated 
dominance hierarchies where larger individuals defend favorable feeding 
positions (Hughes 1992, p. 1996).
General Life History Diversity
    Migratory behavior is a common life-history trait in salmonid 
fishes such as Arctic grayling (Armstrong 1986, pp. 7-8; Northcote 
1995, pp. 156-158; 1997, pp. 1029, 1031-1032, 1034). In general, 
migratory behavior in Arctic grayling and other salmonids results in 
cyclic patterns of movement between refuge, rearing-feeding, and 
spawning habitats (Northcote 1997, p. 1029).
    Arctic grayling may move to refuge habitat as part of a regular 
seasonal migration (e.g., in winter), or in response to episodic 
environmental stressors (e.g., high summer water temperatures). In 
Alaska, Arctic grayling in rivers typically migrate downstream in the 
fall, moving into larger streams or mainstem rivers that do not 
completely freeze (Armstrong 1986, p. 7). In Arctic rivers, fish often 
seek overwintering habitat influenced by groundwater (Armstrong 1986, 
p. 7). In some drainages, individual fish may migrate considerable 
distances (greater than 150 km or 90 mi) to overwintering habitats 
(Armstrong 1986, p. 7). In the Big Hole River, Montana, similar 
downstream and long-distance movement to overwintering habitat has been 
observed in Arctic grayling (Shepard and Oswald 1989, pp. 18-21, 27). 
In addition, Arctic grayling in the Big Hole River may move downstream 
in proximity to colder tributary streams in summer when thermal 
conditions in the mainstem river become stressful (Lamothe and Magee 
2003, p. 17).
    In spring, mature Arctic grayling leave overwintering areas and 
migrate to suitable spawning sites. In river systems, this typically 
involves an upstream migration to tributary streams or shallow riffles 
within the mainstem (Armstrong 1986, p. 8; Shepard and Oswald 1989; p. 
18). Arctic grayling in lakes typically migrate to either the inlet or 
outlet to spawn (Armstrong 1986, p. 8; Kaya 1989, p. 474; Northcote 
1995 p. 148). In some situations, Arctic grayling exhibit natal homing, 
whereby individuals spawn in or near the location where they were born 
(Northcote 1995 pp. 157-160; Boltz and Kaeding 2002, p. 22); however, 
it is unclear what factors may be influencing the extent of this 
phenomenon.
    Fry from river populations typically seek feeding and rearing 
habitats in the vicinity of where they were spawned (Armstrong 1986, 
pp. 6-7; Kaya and Jeanes 1995, p. 455; Northcote 1995, p. 156), while 
those from lake populations migrate downstream (inlet spawners) or 
upstream (outlet spawners) to the adjacent lake. Following spawning, 
adults move to appropriate feeding areas if they are not adjacent to 
spawning habitat (Armstrong 1986, pp. 7-8; Shepard and Oswald 1989; p. 
18). Juvenile Arctic grayling may undertake seasonal migrations between 
feeding and overwintering habitats until they reach maturity and add 
the spawning migration to this cycle (Northcote 1995, pp. 156-157).
Life History Diversity in Arctic Grayling in the Upper Missouri River 
Basin
    Two general life-history forms or ecotypes of native Arctic 
grayling occur in the upper Missouri River Arctic: Fluvial and 
adfluvial. Fluvial fish use river or stream (lotic) habitat for all of 
their life cycles and may undergo extensive migrations within river 
habitat, up to 50 miles in the Big Hole River in Montana (Shepard and 
Oswald 1989, p. 18). Adfluvial fish live in lakes and migrate to 
tributary streams to spawn. These same life-history forms also are 
expressed by Arctic grayling elsewhere in North America (Northcote 
1997, p. 1030). Historically, the fluvial life-history form 
predominated in the Missouri River basin above the Great Falls, perhaps 
because there were only a few lakes accessible to natural colonization 
of Arctic grayling that would permit expression of the

[[Page 49392]]

adfluvial ecotype (Kaya 1992, p. 47). The fluvial and adfluvial life-
history forms of Arctic grayling in the upper Missouri River do not 
appear to represent distinct evolutionary lineages. Instead, they 
appear to represent an example of adaptive radiation (Schluter 2000, p. 
1), whereby the forms differentiated from a common ancestor and 
developed traits that allowed them to exploit different habitats. The 
primary evidence for this conclusion is genetic data that indicate that 
within the Missouri River basin the two ecotypes are more closely 
related to each other than they are to the same ecotype elsewhere in 
North America (Redenbach and Taylor 1999, pp. 27-28; Stamford and 
Taylor 2004, p. 1538; Peterson and Ardren 2009, p. 1766). Historically, 
there may have been some genetic exchange between the two life-history 
forms as individuals strayed or dispersed into different populations 
(Peterson and Ardren 2009, p. 1770), but the genetic structure of 
current populations in the upper Missouri River basin is consistent 
with reproductive isolation.
    The fluvial and adfluvial forms of Arctic grayling appear to differ 
in their genetic characteristics, but there appears to be some 
plasticity in behavior where individuals from a population can exhibit 
a range of behaviors. Arctic grayling fry in Montana can exhibit 
heritable, genetically-based differences in swimming behavior between 
fluvial and adfluvial ecotypes (Kaya 1991, pp. 53, 56-58; Kaya and 
Jeanes 1995, pp. 454, 456). Progeny of Arctic grayling from the fluvial 
ecotype exhibited a greater tendency to hold their position in flowing 
water relative to progeny from adfluvial ecotypes (Kaya 1991, pp. 53, 
56-58; Kaya and Jeanes 1995, pp. 454, 456). Similarly, young Arctic 
grayling from inlet and outlet spawning adfluvial ecotypes exhibited an 
innate tendency to move downstream and upstream, respectively (Kaya 
1989, pp. 478-480). All three studies (Kaya 1989, entire; 1991, entire; 
Kaya and Jeanes 1995, entire) demonstrate that the response of fry to 
flowing water depended strongly on the life-history form (ecotype) of 
the source population, and that this behavior has a genetic basis. 
However, behavioral responses also were mediated by environmental 
conditions (light--Kaya 1991, pp. 56-57; light and water temperature--
Kaya 1989, pp. 477-479), and some progeny of each ecotype exhibited 
behavior characteristic of the other; for example some individuals from 
the fluvial ecotype moved downstream rather than holding position, and 
some individuals from an inlet-spawning adfluvial ecotype held position 
or moved upstream (Kaya 1991, p. 58). These observations indicate that 
some plasticity for behavior exists, at least for very young Arctic 
grayling.
    The ability of the fluvial ecotype to give rise to a functional 
population of the adfluvial ecotype has been demonstrated. Most extant 
adfluvial Arctic grayling populations in the Upper Missouri River 
originated from fluvial-dominated sources (see Table 1; Kaya 1992, p. 
53; Jeanes 1996, pp. 54). However, the ability of the adfluvial ecotype 
to give rise to a functional population of fluvial ecotype is less 
certain. Circumstantial support for reduced plasticity in adfluvial 
Arctic grayling comes from observations that adfluvial fish stocked in 
river habitats almost never establish populations (Kaya 1990, pp. 31-
34). However, we note that adfluvial Arctic grayling retain some life-
history flexibility--at least in lake environments--as naturalized 
populations derived from inlet-spawning stocks have established outlet-
spawning demes (a deme is a local populations that shares a distinct 
gene pool) in Montana and in Yellowstone National Park (Kruse 1959, p. 
318; Kaya 1989, p. 480). In addition, a small percentage of young 
adfluvial Arctic grayling exposed to flow exhibited fluvial-like 
characteristics (e.g., station-holding or upstream movement) in a 
laboratory experiment designed to assess movement tendencies of 
adfluvial and fluvial Arctic grayling in flowing water (Kaya 1991, p. 
56). These results indicate some plasticity exists in adfluvial Arctic 
grayling that may allow some progeny of adfluvial individuals to 
express a fluvial life history. Nonetheless, the frequent failure of 
introductions of adfluvial Arctic grayling into fluvial habitats 
suggest a cautionary approach to the loss of particular life-history 
forms is warranted.
Age and Growth
    Age at maturity and longevity in Arctic grayling varies regionally 
and is probably related to growth rate, with populations in colder, 
northern latitudes maturing at later ages and having a greater lifespan 
(Kruse 1959, pp. 340-341; Northcote 1995 and references therein, pp. 
155-157). Arctic grayling in the upper Missouri River typically mature 
at age 2 (males) or age 3 (females), and individuals greater than age 6 
are rare (Kaya 1990, p. 18; Magee and Lamothe 2003, pp. 16-17). The 
majority of the Arctic grayling spawning in two tributaries in the 
Centennial Valley, Montana, were age 3, and the oldest individuals aged 
from a larger sample were age 6 (Nelson 1954, pp. 333-334). Arctic 
grayling spawning in Red Rock Creek were mostly ages 2 to 5, but some 
individuals were age 7 (Mogen 1996, pp. 32-34).
    Generally, growth rates of Arctic grayling are greatest during the 
first years of life then slow dramatically after maturity. Within that 
general pattern, there is substantial variation among populations from 
different regions. Arctic grayling populations in Montana (Big Hole 
River and Red Rock Lakes) have very high growth rates relative to those 
from British Columbia, Asia, and the interior and North Slope of Alaska 
(Carl et al. 1992, p. 240; Northcote 1995, pp. 155-157; Neyme 2005, p. 
28).

Distinct Vertebrate Population Segment

    Under the Service's Policy Regarding the Recognition of Distinct 
Vertebrate Population Segments Under the Endangered Species Act (61 FR 
4722; February 7, 1996), three elements are considered in the decision 
concerning the establishment and classification of a possible DPS. 
These are applied similarly for additions to or removal from the 
Federal List of Endangered and Threatened Wildlife. These elements 
include:
    (1) The discreteness of a population in relation to the remainder 
of the species to which it belongs;
    (2) The significance of the population segment to the species to 
which it belongs; and
    (3) The population segment's conservation status in relation to the 
Act's standards for listing, delisting, or reclassification (i.e., is 
the population segment endangered or threatened).
Discreteness
    Under the DPS policy, a population segment of a vertebrate taxon 
may be considered discrete if it satisfies either one of the following 
conditions:
    (1) It is markedly separated from other populations of the same 
taxon as a consequence of physical, physiological, ecological, or 
behavioral factors. Quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation.
    (2) It is delimited by international governmental boundaries within 
which differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the Act.
    Arctic grayling native to the upper Missouri River are isolated 
from all other populations of the species, which inhabit the Arctic 
Ocean, Hudson Bay, and north Pacific Ocean drainages in

[[Page 49393]]

Asia and North America. Arctic grayling native to the upper Missouri 
River occur as a disjunct group of populations approximately 800 km 
(500 mi) to the south of the next-nearest Arctic grayling population in 
central Alberta, Canada. Missouri River Arctic grayling have been 
isolated from other populations for at least 10,000 years based on 
historical reconstruction of river flows at or near the end of the 
Pleistocene (Cross et al. 1986, p. 375; Pileou 1991, pp. 10-11). 
Genetic data confirm Arctic grayling in the Missouri River basin have 
been reproductively isolated from populations to the north for 
millennia (Everett 1986, pp. 79-80; Redenbach and Taylor 1999, p. 23; 
Stamford and Taylor 2004, p. 1538; Peterson and Ardren 2009, pp. 1764-
1766; USFWS, unpublished data). Consequently, we conclude that Arctic 
grayling native to the upper Missouri River are markedly separated from 
other native populations of the taxon as a result of physical factors 
(isolation), and therefore meet the first criterion of discreteness 
under the DPS policy. As a result, Arctic grayling native to the upper 
Missouri River are considered a discrete population according to the 
DPS policy. Because the entity meets the first criterion (markedly 
separated), an evaluation with respect to the second criterion 
(international boundaries) is not needed.
Significance
    If a population segment is considered discrete under one or more of 
the conditions described in the Service's DPS policy, its biological 
and ecological significance will be considered in light of 
Congressional guidance that the authority to list DPSs be used 
``sparingly'' while encouraging the conservation of genetic diversity. 
In making this determination, we consider available scientific evidence 
of the discrete population segment's importance to the taxon to which 
it belongs. Since precise circumstances are likely to vary considerably 
from case to case, the DPS policy does not describe all the classes of 
information that might be used in determining the biological and 
ecological importance of a discrete population. However, the DPS policy 
describes four possible classes of information that provide evidence of 
a population segment's biological and ecological importance to the 
taxon to which it belongs. As specified in the DPS policy (61 FR 4722), 
this consideration of the population segment's significance may 
include, but is not limited to, the following:
    (1) Persistence of the discrete population segment in an ecological 
setting unusual or unique to the taxon;
    (2) Evidence that loss of the discrete population segment would 
result in a significant gap in the range of a taxon;
    (3) Evidence that the discrete population segment represents the 
only surviving natural occurrence of a taxon that may be more abundant 
elsewhere as an introduced population outside its historical range; or
    (4) Evidence that the discrete population segment differs markedly 
from other populations of the species in its genetic characteristics.
    A population segment needs to satisfy only one of these conditions 
to be considered significant. Furthermore, other information may be 
used as appropriate to provide evidence for significance.

Unique Ecological Setting

    Water temperature is a key factor influencing the ecology and 
physiology of ectothermic (body temperature regulated by ambient 
environmental conditions) salmonid fishes, and can dictate reproductive 
timing, growth and development, and life-history strategies. 
Groundwater temperatures can be related to air temperatures (Meisner 
1990, p. 282), and thus reflect the regional climatic conditions. 
Warmer groundwater influences ecological factors such as food 
availability, the efficiency with which food is converted into energy 
for growth and reproduction, and ultimately growth rates of aquatic 
organisms (Allan 1995, pp. 73-79). Aquifer structure and groundwater 
temperature is important to salmonid fishes because groundwater can 
strongly influence stream temperature, and consequently egg incubation 
and fry growth rates, which are strongly temperature-dependent (Coutant 
1999, pp. 32-52; Quinn 2005, pp. 143-150).
    Missouri River Arctic grayling occur within the 4 to 7 [deg]C (39 
to 45 [deg]F) ground water isotherm (see Heath 1983, p. 71; an isotherm 
is a line connecting bands of similar temperatures on the earth's 
surface), whereas most other North American Arctic grayling are found 
in isotherms less than 4 [deg]C, and much of the species' range is 
found in areas with discontinuous or continuous permafrost (Meisner et 
al. 1988, p. 5; Table 2). Much of the historical range of Arctic 
grayling in the upper Missouri River is encompassed by mean annual air 
temperature isotherms of 5 to 10 [deg]C (41 to 50 [deg]F) (USGS 2009), 
with the colder areas being in the headwaters of the Madison River in 
Yellowstone National Park. In contrast, Arctic grayling in Canada, 
Alaska, and Asia are located in regions encompassed by air temperature 
isotherms 5 [deg]C and colder (41 [deg]F and colder), with much of the 
species distributed within the 0 to -10 [deg]C isolines (32 to 14 
[deg]F). This difference is significant because Arctic grayling in the 
Missouri River basin have evolved in isolation for millennia in a 
generally warmer climate than other populations. The potential for 
thermal adaptations makes Missouri River Arctic grayling a significant 
biological resource for the species under expected climate change 
scenarios.

    Table 2--Differences Between the Ecological Setting of the Upper
  Missouri River and Elsewhere in the Species' Range of Arctic Grayling
------------------------------------------------------------------------
 Ecological setting variable   Missouri River        Rest of taxon
------------------------------------------------------------------------
Bailey's Ecoregion..........  Dry Domain:      Polar Domain: Tundra &
                               Temperate        Subarctic Humid
                               Steppe.          Temperate: Marine,
                                                Prairie, Warm
                                                Continental Mountains.
Air temperature (isotherm)..  5 to 10 [deg]C   -15 to 5 [deg]C (5 to 41
                               (41 to 50        [deg]F).
                               [deg]F).
Groundwater temperature       4 to 7 [deg]C    Less than 4 [deg]C (Less
 (isotherm).                   (39 to 45        than 39 [deg]F).
                               [deg]F).
------------------------------------------------------------------------

    Arctic grayling in the upper Missouri River basin occur in a 
temperate ecoregion distinct from all other Arctic grayling populations 
worldwide, which occur in Arctic or sub-Arctic ecoregions dominated by 
Arctic flora and fauna. An ecoregion is a continuous geographic area 
within which there are associations of interacting biotic and abiotic 
features (Bailey 2005, pp. S14, S23). These ecoregions delimit large 
areas within which local ecosystems recur more or less in a predictable 
fashion on similar sites (Bailey 2005, p. S14). Ecoregional 
classification is hierarchical, and based

[[Page 49394]]

on the study of spatial coincidences, patterning, and relationships of 
climate, vegetation, soil, and landform (Bailey 2005, p. S23). The 
largest ecoregion categories are domains, which represent 
subcontinental areas of similar climate (e.g., polar, humid temperate, 
dry, and humid tropical) (Bailey 1994; 2005, p. S17). Domains are 
divided into divisions that contain areas of similar vegetation and 
regional climates. Arctic grayling in the upper Missouri River basin 
are the only example of the species naturally occurring in a dry domain 
(temperate steppe division; Table 2). The vast majority of the species' 
range is found in the polar domain (all of Asia, most of North 
America), with small portions of the range occurring in the humid 
temperate domain (northern British Columbia and southeast Alaska). 
Occupancy of Missouri River Arctic grayling in a temperate ecoregion is 
significant for two primary reasons. First, an ecoregion represents a 
suite of factors (climate, vegetation, landform) influencing, or 
potentially influencing, the evolution of species within that 
ecoregion. Since Missouri River Arctic grayling have existed for 
thousands of years in an ecoregion quite different from the majority of 
the taxon, they have likely developed adaptations during these 
evolutionary timescales that distinguish them from the rest of the 
taxon, even if we have yet to conduct the proper studies to measure 
these adaptations. Second, the occurrence of Missouri River Arctic 
grayling in a unique ecoregion helps reduce the risk of species-level 
extinction, as the different regions may respond differently to 
environmental change.
    Arctic grayling in the upper Missouri River basin have existed for 
at least 10,000 years in an ecological setting quite different from 
that experienced by Arctic grayling elsewhere in the species' range. 
The most salient aspects of this different setting relate to 
temperature and climate, which can strongly and directly influence the 
biology of ectothermic species (like Arctic grayling). Arctic grayling 
in the upper Missouri River have experienced warmer temperatures than 
most other populations. Physiological and life-history adaptation to 
local temperature regimes are regularly documented in salmonid fishes 
(Taylor 1991, pp. 191-193), but experimental evidence for adaptations 
to temperature, such as unusually high temperature tolerance or lower 
tolerance to colder temperatures, is lacking for Missouri River Arctic 
grayling because the appropriate studies have not been conducted. Lohr 
et al. (1996, p. 934) studied the upper thermal tolerances of Arctic 
grayling from the Big Hole River, but their research design did not 
include other populations from different thermal regimes, so it was not 
possible to make between-population contrasts under a common set of 
conditions. Arctic grayling from the upper Missouri River demonstrate 
very high growth rates relative to other populations (Northcote 1995, 
p. 157). Experimental evidence obtained by growing fish from 
populations under similar conditions would be needed to measure the 
relative influence of genetics (local adaptation) versus environment.
    We conclude that the occurrence of Arctic grayling in the upper 
Missouri River is biogeographically important to the species, that 
grayling there have occupied a warmer and more temperate setting that 
is distinctly different from the ecological settings relative to the 
rest of the species (see Table 2, above), and that they have been on a 
different evolutionary trajectory for at least 10,000 years. We 
conclude that these differences are significant because they may 
provide the species with additional evolutionary resiliency in the 
future in light of the changing climate. Consequently, we believe that 
Arctic grayling in the upper Missouri River occupy a unique ecological 
setting for the species.

Gap in the Range

    Arctic grayling in Montana (southern extent is approximately 
44[deg]36'23'' N latitude) represent the southern-most extant 
population of the species' distribution since the Pleistocene 
glaciation. The next-closest native Arctic grayling population outside 
the Missouri River basin is found in the Pembina River (approximately 
52[deg]55'6.77'' N latitude) in central Alberta, Canada, west of 
Edmonton (Blackburn and Johnson 2004, pp. ii, 17; ASRD 2005, p. 6). The 
Pembina River drains into Hudson Bay and is thus disconnected from the 
Missouri River basin. Loss of the native Arctic grayling of the upper 
Missouri River would shift the southern distribution of Arctic grayling 
by more than 8[deg] latitude (about 500 miles). Such a dramatic range 
constriction would constitute a significant geographic gap in the 
species' range and would eliminate a genetically distinct group of 
Arctic grayling, which may limit the species' ability to cope with 
future environmental change.
    Marginal populations, defined as those on the periphery of the 
species' range, are believed to have high conservation significance 
(Mitikka et al. 2008; Gibson et al. 2009, entire; Haak et al. 2010, 
entire; Osborne et al. 2012). Peripheral populations may occur in 
suboptimal habitats and thus be subjected to very strong selective 
pressures (Fraser 2000, p. 50). Consequently, individuals from these 
populations may contain adaptations that may be important to the taxon 
in the future. Lomolino and Channell (1998, p. 482) hypothesize that 
because peripheral populations should be adapted to a greater variety 
of environmental conditions, then they may be better suited to deal 
with anthropogenic (human-caused) disturbances than populations in the 
central part of a species' range. Arctic grayling in the upper Missouri 
River have, for millennia, existed in a climate warmer than that 
experienced by the rest of the taxon. If this selective pressure has 
resulted in adaptations to cope with increased water temperatures, then 
the population segment may contain genetic resources important to the 
taxon. For example, if northern populations of Arctic grayling are less 
suited to cope with increased water temperatures expected under climate 
warming, then Missouri River Arctic grayling might represent an 
important population for reintroduction in those northern regions. We 
believe that Arctic grayling's occurrence at the southernmost extreme 
of the range in the upper Missouri River contributes to the resilience 
of the overall taxon because these peripheral populations may possess 
increased adaptability relative to the rest of the taxon.

Only Surviving Natural Occurrence of the Taxon That May Be More 
Abundant Elsewhere as an Introduced Population Outside of Its 
Historical Range

    This criterion does not directly apply to the Arctic grayling in 
the upper Missouri River because it is not the only surviving natural 
occurrence of the taxon; there are native Arctic grayling populations 
in Canada, Alaska, and Asia.

Differs Markedly in Its Genetic Characteristics

    Differences in genetic characteristics can be measured at the 
molecular, genetic, or phenotypic level. Three different types of 
molecular markers (allozymes, mtDNA, and microsatellites) demonstrate 
that Arctic grayling from the upper Missouri River are genetically 
different from those in Canada, Alaska, and Asia (Everett 1986, pp. 79-
80; Redenbach and Taylor 1999, p. 23; Stamford and Taylor 2004, p. 
1538; Peterson and Ardren 2009, pp. 1764-1766; USFWS, unpublished 
data). These

[[Page 49395]]

data confirm the reproductive isolation among populations that 
establishes the discreteness of Missouri River Arctic grayling under 
the DPS policy. Here, we speak to whether these data also establish 
significance.
Allozymes
    Using allozyme data, Everett (1986, entire) found marked genetic 
differences among Arctic grayling collected from the Chena River in 
Alaska; those descended from fish native to the Athabasca River 
drainage in the Northwest Territories, Canada; and native upper 
Missouri River drainage populations or populations descended from them 
(see Leary 2005, pp. 1-2). The Canadian population had a high frequency 
of two unique alleles (forms of a gene), which strongly differentiated 
them from all the other samples (Everett 1986, p. 44). With the 
exception of one introduced population in an irrigation canal 
(Sunnyslope canal) in Montana that is believed to have experienced 
extreme genetic bottlenecks, the Chena River (Alaskan) fish were highly 
divergent from all the other samples as they possessed an unusually low 
frequency of a specific allele (Everett 1986, p. 60; Leary 2005, p. 1), 
and contained a unique variant of another allele (Leary 2005, p. 1). 
Overall, each of the four native Missouri River populations examined 
(Big Hole, Miner, Mussigbrod, and Centennial Valley) exhibited 
statistically significant differences in allele frequencies relative to 
both the Chena River (Alaska) and Athabasca River (Canada) populations 
(Everett 1986, pp. 15, 67).
    Combining the data of Everett (1986, entire), Hop and Gharrett 
(1989, entire), and Leary (1990, entire) provides information from 21 
allozyme loci (genes) from five native upper Missouri River drainage 
populations, five native populations in the Yukon River drainage in 
Alaska, and the one population descended from the Athabasca River 
drainage in Canada (Leary 2005, pp. 1-2). Examination of the genetic 
variation in these samples indicated that most of the genetic 
divergence is due to differences among drainages (29 percent) and 
comparatively little (5 percent) results from differences among 
populations within a drainage (Leary 2005, p. 1).
Mitochondrial DNA
    Analysis using mtDNA indicates that Arctic grayling in North 
America represent at least three evolutionary lineages that are 
associated with distinct glacial refugia (Redenbach and Taylor 1999, 
entire; Stamford and Taylor 2004, entire). Arctic grayling in the upper 
Missouri River basin belong to the so-called North Beringia lineage 
(Redenbach and Taylor 1999, pp. 27-28; Samford and Taylor 2004, pp. 
1538-1540) because they possess a form of mtDNA that was generally 
absent from populations collected from other locations within the 
species' range in North America (Redenbach and Taylor 1999, pp. 27-28; 
Stamford and Taylor 2004, p. 1538). The notable exceptions were that 
some fish from the lower Peace River drainage in British Columbia, 
Canada, and all sampled individuals from the Saskatchewan River 
drainage Saskatchewan, Canada, also possessed this form of mtDNA 
(Stamford and Taylor 2004, p. 1538).
    A form of mtDNA common in upper Missouri River Arctic grayling, 
which occurs at lower frequencies in other populations, indicates that 
Arctic grayling native to the upper Missouri River drainage probably 
originated from a glacial refuge in the drainage and subsequently 
migrated northwards when the Missouri River temporarily flowed into the 
Saskatchewan River and was linked to an Arctic drainage (Cross et al. 
1986, pp. 374-375; Pielou 1991, p. 195). When the Missouri River began 
to flow southwards because of the advance of the Laurentide ice sheet 
(Cross et al. 1986, p. 375; Pileou 1991, p. 10), the Arctic grayling in 
the drainage became physically and reproductively isolated from the 
rest of the species' range (Leary 2005, p. 2; Campton 2004, p. 6), 
which would have included those populations in Saskatchewan. 
Alternatively, the Missouri River Arctic grayling could have 
potentially colonized Saskatchewan or the Lower Peace River (in British 
Columbia) or both post-glacially (Stamford 2001, p. 49) via a gap in 
the Cordilleran and Laurentide ice sheets (Pielou 1991, pp. 10-11), 
which also might explain the low frequency 'Missouri River'' mtDNA in 
Arctic grayling in the Lower Peace River and Upper Yukon River.
    We do not interpret the observation that Arctic grayling in Montana 
and Saskatchewan, and to lesser extent those from the Lower Peace and 
Upper Yukon River systems, share a mtDNA haplotype to mean that these 
groups of fish are genetically identical. Rather, we interpret it to 
mean that these fish shared a common ancestor tens to hundreds of 
thousands of years ago.
Microsatellite DNA
    Recent analysis of microsatellite DNA (highly variable portions of 
nuclear DNA) showed substantial divergence between Arctic grayling in 
Missouri River and Saskatchewan populations (Peterson and Ardren 2009, 
entire). This divergence between populations was measured in terms of 
allele frequencies, using a metric called Fst (Allendorf and Luikart 
2007, pp. 52-54, 198-199). An analogous metric, named Rst, also 
measures genetic differentiation between populations based on 
microsatellite DNA, but differs from Fst in that it also considers the 
size differences between alleles (Hardy et al. 2003, p. 1468). An Fst 
or Rst of 0 indicates that populations are the same genetically, 
whereas a value of 1 indicates the populations share no genetic 
material at the markers being surveyed. Fst values range from 0.13 to 
0.31 (average 0.18) between Missouri River and Saskatchewan populations 
(Peterson and Ardren 2009, pp. 1758, 1764-1765), whereas Rst values 
range from 0.47 to 0.71 (average 0.54) for the same comparisons 
(Peterson and Ardren 2009, pp. 1758, 1764-1765). These values indicate 
that the two populations differ significantly in allele frequency and 
also in the size of those alleles. This outcome indicates that the 
observed genetic differences are due to mutational differences, which 
suggests the groups may have been separated for millennia (Peterson and 
Ardren 2009, pp. 1767-1768).
    Analysis of Arctic grayling populations from Alaska, Canada, and 
the Missouri River basin using nine of the same microsatellite loci as 
Peterson and Ardren (2009, entire) further supports the distinction of 
Missouri River Arctic grayling relative to populations elsewhere in 
North America (USFWS, unpublished data). This analysis clearly 
separated sample fish from 21 populations into two clusters: One 
cluster representing populations from the upper Missouri River basin, 
and another cluster representing populations from across Canada and 
Alaska (USFWS, unpublished data). Divergence in size among these 
alleles further supports the distinction between Missouri River Arctic 
grayling and those in Canada and Alaska (USFWS, unpublished data). The 
interpretation of these data is that the Missouri River populations and 
the Canada/Alaska populations are highly genetically distinct at the 
microsatellite loci considered.
Phenotypic Characteristics Influenced by Genetics--Meristics
    Phenotypic variation can be evaluated by counts of body parts 
(i.e., meristic counts of the number of gill rakers, fin rays, and 
vertebrae characteristics of a population) that can vary within and 
among species. These meristic traits are influenced by both genetics 
and the environment (Allendorf and Luikart

[[Page 49396]]

2007, pp. 258-259). When the traits are controlled primarily by genetic 
factors, then meristic characteristics can indicate significant genetic 
differences among groups. Arctic grayling north of the Brooks Range in 
Alaska and in northern Canada had lower lateral line scale counts than 
those in southern Alaska and Canada (McCart and Pepper 1971, entire). 
These two scale-size phenotypes are thought to correspond to fish from 
the North and South Beringia glacial refuges, respectively (Stamford 
and Taylor 2004, p. 1545). Arctic grayling from the Centennial Valley 
had a phenotype intermediate to the large- and small-scale types 
(McCart and Pepper 1971, pp. 749, 754). Arctic grayling populations 
from the Missouri River (and one each from Canada and Alaska) could be 
correctly assigned to their group 60 percent of the time using a suite 
of seven meristic traits (Everett 1986, pp. 32-35). Those native 
Missouri River populations that had high genetic similarity also tended 
to have similar meristic characteristics (Everett 1986, pp. 80, 83).
    Arctic grayling from the Big Hole River showed marked differences 
in meristic characteristics relative to two populations from Siberia, 
and were correctly assigned to their population of origin 100 percent 
of the time (Weiss et al. 2006, pp. 512, 515-516, 518). The populations 
that were significantly different in terms of their meristic 
characteristics also exhibited differences in molecular genetic markers 
(Weiss et al. 2006, p. 518).
Inference Concerning Genetic Differences in Arctic Grayling of the 
Missouri River Relative to Other Examples of the Taxon
    We believe the differences between Arctic grayling in the Missouri 
River and sample populations from Alaska and Canada measured using 
allozymes (Everett 1986, entire; Leary 2005, entire), mitochondrial DNA 
(Redenbach and Taylor 1999, entire; Stamford and Taylor 2004, entire), 
and microsatellite DNA markers (Peterson and Ardren 2009, pp. 1764-
1766; USFWS, unpublished data) represent ``marked genetic differences'' 
in terms of the extent of differentiation (e.g., Fst, 
Rst) and the importance of that genetic legacy to the rest 
of the taxon. The presence of morphological characteristics separating 
Missouri River Arctic grayling from other populations also likely 
indicates genetic differences, although this conclusion is based on a 
limited number of populations (Everett 1986, pp. 32-35; Weiss et al. 
2006, entire), and we cannot entirely rule out the influence of 
environmental variation.
    The intent of the DPS policy and the Act is to preserve important 
elements of biological and genetic diversity, not necessarily to 
preserve the occurrence of unique alleles in particular populations. In 
Arctic grayling of the Missouri River, the microsatellite DNA data 
indicate that the group is evolving independently from the rest of the 
species. The extirpation of this group would mean the loss of the 
genetic variation in one of the two most distinct groups identified in 
the microsatellite DNA analysis, and the loss of the future 
evolutionary potential that goes with it. Thus, the genetic data 
support the conclusion that Arctic grayling of the upper Missouri River 
represent a unique and irreplaceable biological resource of the type 
the Act was intended to preserve. Thus, we conclude that Missouri River 
Arctic grayling differ markedly in their genetic characteristics 
relative to the rest of the taxon.
    Upper Missouri River Arctic grayling satisfy the significance 
criteria outlined in the Services' DPS policy because they occur in a 
unique ecological setting, are separated from other Arctic grayling 
populations by a large gap in their range, and differ markedly in their 
genetic characteristics relative to other Arctic grayling populations. 
Therefore, we consider the Arctic grayling in the upper Missouri River 
basin significant to the taxon to which it belongs under the Service's 
DPS policy.
Determination of Distinct Population Segment
    We find that a population segment that includes all native ecotypes 
of Arctic grayling in the upper Missouri River basin satisfies the 
discreteness standard of the DPS policy. The segment is physically 
isolated, and genetic data indicate that Arctic grayling in the 
Missouri River basin have been separated from other populations for 
thousands of years. The population segment occurs in an isolated 
geographic area far south of all other Arctic grayling populations 
worldwide, and we find that loss of this population segment would 
create a significant gap in the species' range. Molecular genetic data 
clearly differentiate Missouri River Arctic grayling from other Arctic 
grayling populations, including those in Canada and Alaska.
    Based on the best scientific and commercial information available, 
as described above, we find that, under the Service's DPS policy, upper 
Missouri River Arctic grayling are discrete and are significant to the 
taxon to which they belong. Because the upper Missouri River population 
of Arctic grayling is both discrete and significant, it qualifies as a 
DPS under the Act.
    As we described above, we are including introduced Arctic grayling 
populations that occur in lakes in the upper Missouri River basin as 
part of the DPS. The Service has interpreted the Act to provide a 
statutory directive to conserve species in their native ecosystems (49 
FR 33885; August 27, 1984) and to conserve genetic resources and 
biodiversity over a representative portion of a taxon's historical 
occurrence (61 FR 4722; February 7, 1996). The introduced Arctic 
grayling populations occur within the boundaries of the upper Missouri 
River basin and represent moderate to high levels of genetic diversity 
from within the basin. The future adaptive capabilities represented by 
this genetic diversity have conservation value, particularly given a 
changing climate.
    We define the historical range of this population segment to 
include the major streams, lakes, and tributary streams of the upper 
Missouri River (mainstem Missouri, Smith, Sun, Beaverhead, Jefferson, 
Big Hole, and Madison Rivers, as well as their key tributaries, as well 
as a few small lakes where Arctic grayling are or were believed to be 
native (Elk Lake, Red Rock Lakes in the Centennial Valley, Miner Lake, 
and Mussigbrod Lake, all in Beaverhead County, Montana)). We define the 
current range of the DPS to consist of extant native populations in the 
Big Hole River, Miner Lake, Mussigbrod Lake, Madison River-Ennis 
Reservoir, and Centennial Valley, as well as all known introduced 
populations within the upper Missouri River basin. We refer to this 
entity as the Upper Missouri River DPS of Arctic grayling. The 
remainder of this finding will thus focus on the population status of 
and potential threats to this entity.
Population Status and Trends of Populations in the Upper Missouri River 
DPS
    The Upper Missouri River DPS of Arctic grayling is comprised of 20 
populations, including 2 fluvial populations and 16 adfluvial 
populations. Two other populations (Centennial Valley and Madison 
River/Ennis Reservoir) appear to exhibit both fluvial and adfluvial 
components (Table 3). Arctic grayling from the Centennial Valley (Long 
Creek) and Ennis Reservoir/Madison River (mainstem Madison River) have 
been documented well past the spawning period through autumn. These 
occurrences are more prevalent in Long Creek in the Centennial Valley 
than in the Madison

[[Page 49397]]

River population and do not appear to be linked to individual Arctic 
grayling seeking thermal refugia during summer (Montana Arctic Grayling 
Workgroup (AGW) 1995; p. 1; Cayer 2014a, pers. comm.; MFISH 2014b, 
unpublished data). These occurrences include multiple age classes (Age-
1 to Age-3) of Arctic grayling in both Long Creek and the Madison River 
and are located in stream reaches that are considerable distances (up 
to 15 miles in the Madison River) from adfluvial habitats (Cayer 2014a, 
pers. comm.; MFISH 2014b, unpublished data). Eighteen of the 20 
populations occur solely on Federal or majority Federal land; the 
remaining two (Big Hole River and Ennis Reservoir/Madison River) occur 
on primarily private land.
BILLING CODE 4310-55-P

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[GRAPHIC] [TIFF OMITTED] TP20AU14.001

BILLING CODE 4310-55-C
    Estimated abundance of reproductively mature individuals in the two 
fluvial populations varies from about one hundred to several thousand

[[Page 49399]]

Arctic grayling (Table 3). Where quantitative data are available, 
estimated abundance of mature individuals in adfluvial populations 
(including the two populations exhibiting both life histories) varies 
from a few hundred to around 25,000 Arctic grayling. Most populations 
are currently stable or increasing in abundance, with the exception of 
the Ennis Reservoir/Madison River population (Table 3).
Distinct Population Segment Five-Factor Analysis
    Since the Arctic grayling in the upper Missouri River basin 
qualifies as a DPS, we will now evaluate its status with regard to its 
potential for listing as endangered or threatened based on the five 
factors enumerated in section 4(a) of the Act. Our evaluation of the 
Upper Missouri River DPS of Arctic grayling follows.

Summary of Information Pertaining to the Five Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR 424) set forth procedures for adding species to, removing 
species from, or reclassifying species on the Federal Lists of 
Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of 
the Act, a species may be determined to be endangered or threatened 
based on 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; or
    (E) Other natural or manmade factors affecting its continued 
existence.
    In making this finding, information pertaining to the Upper 
Missouri River DPS of Arctic grayling in relation to the five factors 
provided in section 4(a)(1) of the Act is discussed below. In 
considering what factors might constitute threats, we must look beyond 
the mere exposure of the species to the factor to determine whether the 
species responds to the factor in a way that causes actual impacts to 
the species. If there is exposure to a factor, but no response, or only 
a positive response, that factor is not a threat. If there is exposure 
and the species responds negatively, the factor may be a threat and we 
then attempt to determine how significant a threat it is. If the threat 
is significant, it may drive or contribute to the risk of extinction of 
the species such that the species warrants listing as endangered or 
threatened as those terms are defined by the Act. This does not 
necessarily require empirical proof of a threat. The combination of 
exposure and some corroborating evidence of how the species is likely 
impacted could suffice. The mere identification of factors that could 
impact a species negatively 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 or threatened species under the 
Act.
    In making our revised 12-month finding on the petition, we consider 
and evaluate the best available scientific and commercial information. 
This evaluation includes all factors we previously considered in the 
2010 finding and, at the end of this analysis, explains how the 
Services' conclusions differ now.

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

Curtailment of Range and Distribution
    The range and distribution of fluvial Arctic grayling in the upper 
Missouri River basin was reduced over the past 100 years (Kaya 1992, p. 
51), primarily due to historical habitat fragmentation by dams and 
irrigation diversions and by habitat degradation or modification from 
unregulated land use (Vincent 1962, pp. 97-121). Fluvial Arctic 
grayling typically need large expanses of connected habitat to fulfill 
their life-history stages (Armstrong 1986, p. 8). For example, fluvial 
Arctic grayling in the Big Hole River have been documented migrating 
over 60 miles (97 km) between overwintering, spawning, and foraging 
habitats (Shepard and Oswald 1989, pp. 18-21, 27). These past 
reductions in range and distribution reproductively isolated fluvial 
Arctic grayling populations within the basin (Peterson and Ardren 2009, 
p. 1770).
    Although the range and distribution of fluvial Arctic grayling has 
contracted from historical levels, expression of the fluvial life 
history is represented, at least in part, in four Arctic grayling 
populations within the Upper Missouri River DPS. Whether strictly 
fluvial (e.g., Big Hole and Ruby River) or partially fluvial (e.g., 
Centennial Valley (Long Creek) and Ennis Reservoir/Madison River 
(mainstem Madison River)), these populations occur in four watersheds 
where large reaches of connected habitat remain and still permit the 
expression of the fluvial life history, despite the presence of 
mainstem dams in three of four watersheds (Kaya 1992, entire; see 
Figure 1). Thus, despite historical curtailment of range, the amount of 
connected habitat in some systems is adequate to permit the expression 
of the fluvial life history.
    Of the four Arctic grayling populations still expressing a fluvial 
life history, three of four populations (Big Hole River, Centennial 
Valley, and Ruby River) are currently increasing in abundance (see 
Table 3). In each of these populations, as abundance increases, there 
is a corresponding increase in distribution. Natural reproduction is 
occurring in all three of these populations. In the Big Hole River and 
the Centennial Valley, remote site incubators (RSIs) have been used as 
a conservation tool to help facilitate increased abundance and 
distribution of Arctic grayling. Thus, observed increases in abundance 
and distribution may be partially attributable to the use of RSIs (for 
more in-depth discussion on RSI use, see ``Native Arctic Grayling 
Genetic Reserves and Translocation,'' below). Given the above 
information, it appears that three of four fluvial, or partly fluvial, 
populations are viable and have the necessary configuration and amount 
of habitat to fulfill their life-history needs. Thus, effects of past 
range curtailment on the fluvial component of Arctic grayling in the 
upper Missouri River basin are present, but there appears to be 
sufficient adequate habitat remaining to support expression of the 
fluvial life history.
    Adfluvial Arctic grayling populations in the upper Missouri River 
basin are present in all lakes originally thought to have had native 
populations historically (Miner, Mussigbrod, Upper Red Rock, and Elk 
Lakes (present but not included in Table 3, above, because of uncertain 
viability)). Thus, there has been no contraction of the range of 
adfluvial populations. Given the above information, curtailment of 
range and distribution is not precluding the expression of either 
fluvial or adfluvial life history. Although curtailment of range and 
distribution occurred historically, Arctic grayling populations are 
still present in 7 of 10 historically occupied watersheds in the upper 
Missouri River basin (see ``Drainage'' column in Table 3). Accordingly, 
we have no evidence that curtailment of range and distribution is a 
current threat to the DPS. In addition, we have no information 
suggesting curtailment of range and distribution will be a threat in 
the future.
Dams on Mainstem Rivers
    Much of the historical range of the Upper Missouri River DPS of 
Arctic

[[Page 49400]]

grayling has been altered by the construction of dams and reservoirs 
(Kaya 1990, pp. 51-52; Kaya 1992, p. 57). The construction of large 
dams on mainstem river habitats throughout the upper Missouri River 
system fragmented river corridors necessary for the expression of 
Arctic grayling migratory life histories in some systems. Construction 
of dams that obstructed fish passage on the mainstem Missouri River 
(Hauser, Holter, Canyon Ferry, and Toston dams), Madison River 
(Madison-Ennis, Hebgen dams), Beaverhead River and its tributary Red 
Rock River (Clark Canyon, Lima dams), Ruby River (Ruby dam), and Sun 
River (Gibson dam) all likely contributed to the historical decline of 
fluvial Arctic grayling in the DPS (Vincent 1962, pp. 127-128; Kaya 
1992, p. 57). Lack of fish passage at these dams contributed to the 
extirpation of fluvial Arctic grayling from some waters by blocking 
migratory corridors (Vincent 1962, p. 128), curtailing access to 
important spawning and rearing habitats, and impounding water over 
former spawning locations (Vincent 1962, p. 128). Most dams within the 
upper Missouri River basin were constructed between 1905 and 1960 (Kaya 
1990, entire).
    Despite the construction of multiple dams throughout the historical 
range of Arctic grayling, multiple populations, or portions of 
populations, of the fluvial ecotype are still represented in the DPS. 
These populations reside in areas where sufficient quantity and quality 
of habitat exist and permit the expression of this life history. In 
some cases, dams may be providing a benefit, because currently many of 
the dams that historically affected fluvial Arctic grayling populations 
are now precluding invasion by nonnative fish from downstream sources. 
For example, Lima Dam in the Centennial Valley is currently precluding 
brown trout invasion from downstream sources (Mogen 2014, pers. comm). 
Currently, there are five Arctic grayling populations within the DPS 
that occur above mainstem dams (Centennial Valley, Ruby River, Hyalite 
Lake, Diversion Lake, and Gibson Reservoir) with at least one nonnative 
fish species occurring downstream of these dams (MFISH 2014d, 
unpublished data).
    Some reservoirs created by dams are currently being used by Arctic 
grayling as overwintering, rearing and foraging areas. Both adult and 
juvenile Arctic grayling use Ennis Reservoir for overwintering, 
rearing, and foraging (Byorth and Shepard 1990, entire). In the 
Centennial Valley, Arctic grayling have recently been detected in Lima 
Reservoir (MFISH 2014e, unpublished data). The movements of Arctic 
grayling within and out of Lima Reservoir are unknown; however, Lima 
Reservoir is a large reservoir and, as such, is likely used for 
overwintering purposes.
    Arctic grayling have been documented in stream and river reaches 
below some dams, most likely indicating downstream passage of fish over 
or through dams. These fish are essentially ``lost'' to the population 
residing above the dam, because none of the mainstem river dams in the 
upper Missouri River basin provides upstream fish passage. Substantial 
losses from a population resulting from downstream entrainment of fish 
through dams could cause declines in reproductive potential and 
abundance in the reservoir population above the dam (Kimmerer 2008, 
entire). However, it is unknown what entrainment rates currently are in 
populations residing near dams. Rate of entrainment is likely dependent 
on a number of factors, including dam operations, season, water 
conditions in the reservoir, initial population size above the dam, 
etc. Recent monitoring data and angler reports of Arctic grayling 
observed downstream of reservoirs supporting Arctic grayling 
populations are sporadic (Horton 2014c, pers. comm.; SSA 2014); thus it 
appears the threat of mainstem dams is likely affecting some 
individuals, but not affecting populations or the DPS as a whole.
    Historically, operational practices at Madison Dam have likely 
affected the Arctic grayling population in Ennis Reservoir/Madison 
River. A population decline in Arctic grayling appeared to coincide 
with a reservoir drawdown in the winter of 1982-1983 (Byorth and 
Shepard 1990, pp. 52-53). This drawdown likely affected the forage 
base, rearing habitat, and spawning cycle of Arctic grayling in the 
reservoir. However, under a new licensing agreement dated September 27, 
2000, between the Federal Energy Regulatory Commission and Ennis Dam 
operators, such substantial drawdowns in elevation of Ennis Reservoir 
are no longer permitted (Clancey 2014, pers. comm.).
    Given the above information, mainstem dams were a historical threat 
to Arctic grayling populations in the upper Missouri River basin. Dams 
still impact individuals, because some Arctic grayling are currently 
being entrained and lost from their source population. In Ennis 
Reservoir, the new licensing agreement is expected to reduce the 
effects of dam operations on the Arctic grayling population. Most 
Arctic grayling populations residing above dams are stable or 
increasing; thus, it does not appear this impact is acting at the 
population or DPS level. We have no information to conclude that 
mainstem dams will be a threat in the future at the population or DPS 
level.
Water Management in the Upper Missouri River Basin
    The predominant use of private lands in the upper Missouri River 
basin is irrigated agriculture and ranching. These activities have 
historically had significant effects on aquatic habitats, primarily 
changes in water availability and alteration of the structure and 
function of aquatic habitats. Changes in water availability can affect 
Arctic grayling reproduction, survival, and movements among habitat 
types (Kaya 1990, entire).
    In contrast to most of the Arctic grayling populations in the Upper 
Missouri River DPS that occur on Federal land, the fluvial population 
of Arctic grayling in the Big Hole River occurs on primarily (~90 
percent) private land. Thus, any conservation efforts conducted in the 
Big Hole River Valley need support from involved agencies and private 
landowners. In 2006, a candidate conservation agreement with assurances 
(CCAA; Montana Fish, Wildlife, and Parks et al. 2006, entire) was 
developed for Arctic grayling in the Big Hole River. The conservation 
goal of this CCAA is to secure and enhance the fluvial population of 
Arctic grayling in the upper Big Hole River drainage. Conservation 
projects conducted under the CCAA are prioritized and guided by the Big 
Hole Arctic Grayling Strategic Habitat Conservation Plan (SHCP) (for 
more specific information, see ``Conservation Efforts to Reduce Habitat 
Destruction, Modification, or Curtailment of Its Range,'' below).
    Since 2006, many conservation and restoration projects have been 
completed in the upper Big Hole River under the direction of the CCAA 
and SHCP (Table 4). Below, we describe and evaluate the implementation 
and effectiveness of these projects relative to the potential stressors 
analyzed under Factor A for the Big Hole River population. We also 
analyze the effects of potential stressors under Factor A for the other 
Arctic grayling populations in the DPS.

[[Page 49401]]



      Table 4--Conservation Projects and Results, and Arctic Grayling Response in the Big Hole River Since
                                   Implementation of the Big Hole CCAA in 2006
   [All information on conservation projects and conservation results cited from the Big Hole Arctic Grayling
                                      Strategic Habitat Conservation Plan]
----------------------------------------------------------------------------------------------------------------
                                               Conservation projects                           Arctic grayling
     Threat factor             Stressor                 \a\            Conservation result        response
----------------------------------------------------------------------------------------------------------------
A.....................  Dams/habitat           Fish ladders: 41.....  Stream miles (%)       Number of
                         fragmentation.        Bridges: 7...........   accessible to         breeding adults has
                                               Grade control           grayling \b\:         increased from ~100
                                                structures: 2.         Tier I-       (2007-2011) to 500-
                                                                       82(98%; pre-          900 \c\ (2013)
                                                                       CCAA=87%)..           (Leary 2014,
                                                                       Tier II-      unpublished data).
                                                                       61(67%; pre-
                                                                       CCAA=27%)..
                                                                       Tier III-
                                                                       32(20%: pre-
                                                                       CCAA=6%)..
                        Dewatering/Thermal     PODs: 343 of 504 with                 Arctic
                         stress.                signed SSPs.              Achievement of     grayling abundance
                                               Irrigation                 instream flow      \d\ (catch per unit
                                                improvements: 88.         goals increased    effort) increased
                                               Water measuring            from 50% (pre-     from 0.2 fish/mile
                                                devices: 67.              CCAA) to 78%       (2008) to 1.4 fish/
                                               Stock water systems:       (post-CCAA).       mile (2012) in the
                                                63.                    Landowner     CCAA monitoring
                                               Stream restoration:     contributions to      reaches of the
                                                26 miles.              streamflow            mainstem Big Hole
                                               Rock Creek              increasing as         River (MFWP 2013a,
                                                restoration.            of PODs     unpublished data).
                                                                       with signed SSPs
                                                                       increase [landowner
                                                                       contribution to
                                                                       instream flows in
                                                                       Big Hole River (pre-
                                                                       2006 = 0 cfs; 2013
                                                                       = 250 cfs)].
                                                                       Temperature
                                                                       reductions in
                                                                       tributaries (see
                                                                       Rock Creek example
                                                                       below).
                                                                      Pre-restoration        Arctic
                                                                       (2007):.              grayling abundance
                                                                       36 days       \d\ (catch per unit
                                                                       max. temp >70         effort) increased
                                                                       [deg]F.               from 2.9 fish/mile
                                                                       16 days       (2008) to 7.4 fish/
                                                                       max. temp >77         mile (2012) in the
                                                                       [deg]F.               CCAA monitoring
                                                                      Post-restoration       tributaries (MFWP
                                                                       (2013):.              2013a, unpublished
                                                                       0 days max    data).
                                                                       temp. >70 [deg]F.     Arctic
                                                                                             grayling
                                                                                             distribution has
                                                                                             increased 4 miles
                                                                                             in Rock Creek
                                                                                             (young-of-year and
                                                                                             Age 1+) and 2 miles
                                                                                             in Big Lake Creek
                                                                                             (Age 1+) since 2006
                                                                                             (SHCP 2013, p. 12).
Entrainment...........  Fish screens: 2......      No
                        Prioritized                entrainment
                         monitoring protocol.      documented since
                                                   2010.
                                                Observed low
                                                entrainment rates in
                                                unscreened ditches
                                                (73 Arctic grayling/
                                                138 ditch miles).
 
Riparian habitat loss.  Stream restoration:     110 miles
                         26 miles.              (65%) of riparian
                        Riparian fencing: 108   habitat on enrolled
                         miles.                 lands improving.
                        Stock water systems:    15% increase
                         63.                    in sustainable
                        Grazing mgmt. plans:    riparian areas from
                         21 landowners          32% (2006) to 47%
                         (85,000 ac.).          (2013).
                        Noxious weed            Adaptive
                         management.            management in place
                        Willow planting         to address non-
                         (72,200 planted).      improving areas.
----------------------------------------------------------------------------------------------------------------
\a\ PODs = Points of Diversion, SSPs = Site-specific plans; \b\ Tier I is core spawning, rearing and adult
  habitat that is currently occupied by Arctic grayling, Tier II is periphery habitat intermittently used by
  Arctic grayling, Tier III is suitable, but currently unoccupied historical habitat; \c\ The estimate of number
  of breeding adults in the Big Hole River in 2013 is reported as a range because of uncertainty in the
  frequency rate of rare alleles in the analysis; \d\ Abundance estimates from 2013 were lower than those
  reported for 2012 likely due to unusually high flows (3X normal) concurrent with fall sampling that likely
  decreased capture efficiency, resulting in lower abundance estimates in 2013.


[[Page 49402]]

Habitat Fragmentation/Smaller Seasonal Barriers
    Big Hole River: Smaller dams or diversions associated with 
irrigation structures historically posed a threat to Arctic grayling 
migratory behavior, especially in the Big Hole River drainage. In the 
Big Hole River, numerous diversion structures have been identified as 
putative fish migration barriers (Petersen and Lamothe 2006, pp. 8, 12-
13, 29) that may limit the ability of Arctic grayling to migrate to 
spawning, rearing, or sheltering habitats under certain conditions. As 
with the larger dams, these smaller fish passage barriers can reduce 
reproduction (access to spawning habitat is blocked), reduce growth 
(access to feeding habitat is blocked), and increase mortality (access 
to refuge habitat is blocked). Historically, these types of barriers 
were numerous and widespread across the Big Hole River drainage.
    Currently, habitat fragmentation due to irrigation diversion 
structures in the Big Hole is being systematically reduced under the 
CCAA for Fluvial Arctic Grayling in the upper Big Hole River 
(hereafter, Big Hole CCAA or CCAA; for more specific information, see 
``Conservation Efforts to Reduce Habitat Destruction, Modification, or 
Curtailment of Its Range'') and Big Hole Arctic Grayling SHCP. Since 
2006, 41 fish ladders have been installed in the mainstem Big Hole 
River and tributaries (Table 4). Multiple culverts have been replaced 
with bridges and several grade control structures have been installed 
(Table 4). As a result, no fish barriers now exist in the mainstem 
upper Big Hole River. Almost all (98 percent) of tier I habitat and the 
majority (68 percent) of tier II habitat is connected and accessible to 
Arctic grayling (Table 4): 67 miles of stream have been reconnected in 
the Big Hole River system since 2006 (MFWP 2014a, unpublished data).
    Other populations: Smaller fish passage barriers also have been 
noted to affect Arctic grayling in the Centennial Valley (Unthank 1989, 
p. 9). Historically, spawning Arctic grayling migrated from the 
Jefferson River system, through the Beaverhead River and Red Rock River 
through the Red Rock Lakes and into the upper drainage, and then 
returned downstream after spawning (Henshall 1907, p. 5). The 
construction of a water control structure (sill) at the outlet of Lower 
Red Rock Lake in 1930 (and reconstruction in 1957 (USFWS 2009, p. 74)) 
created an upstream migration barrier that blocked these migrations 
(Unthank 1989, p. 10; Gillin 2001, p. 4-4). However, recent changes in 
water management at the Red Rock Lakes National Wildlife Refuge (NWR) 
have resulted in year-round fish passage through the control structure 
at the outlet of Lower Red Rock Lake (West 2013, pers. comm.).
    In Mussigbrod Lake, Arctic grayling occasionally pass downstream 
over a diversion structure at the lake outlet, and become trapped in an 
isolated pool (Olsen 2014, pers. comm.). During high-snowpack years, 
Arctic grayling likely can swim back up to the lake from the pool, but 
in low snowpack years, some Arctic grayling perish when the isolated 
pool dries up (Olsen 2014, pers. comm.). However, this phenomenon has 
occurred periodically in recent history and has had no discernible 
impacts on Arctic grayling abundance in Mussigbrod Lake (Olsen 2014, 
pers. comm.).
    All 16 adfluvial Arctic grayling populations in the upper Missouri 
River basin occur on Federal land (U.S. Forest Service) and are not 
influenced by irrigation structures because none are present. The 
effect of a barrier at the outlet of Mussigbrod Lake is likely 
impacting individuals, but not the population because of the robust 
population size in Mussigbrod Lake and historical stability of that 
population since the outlet structure was created. Based on this 
information, we conclude that the threats from habitat fragmentation 
have been sufficiently mitigated or minimized and are no longer are 
acting as a stressor at the population or DPS level.
Degradation of Riparian Habitat
    Riparian corridors are important for maintaining habitat for Arctic 
grayling in the upper Missouri River basin, and in general are critical 
for the ecological function of aquatic systems (Gregory et al. 1991, 
entire). Riparian zones are important for Arctic grayling because of 
their effect on water quality and water temperature, and their role in 
maintaining natural ecological process responsible for creating and 
maintaining necessary physical habitat features (i.e., pools, riffles, 
and scour areas) used by the species to meet its life-history 
requirements.
    Big Hole: Arctic grayling abundance in the upper Big Hole River is 
positively related to the presence of overhanging vegetation, primarily 
willows (Salix spp.), that is associated with pool habitat (Lamothe and 
Magee 2004, pp. 21-22). Removal of willows and riparian clearing 
concurrent with livestock and water management along the upper Big Hole 
River has led to a shift in channel form (i.e., braided channels 
becoming a single wide channel), increased erosion rates, reduced 
cover, increased water temperatures, and reduced recruitment of large 
wood debris into the active stream channel (Confluence Consulting et 
al. 2003, pp. 24-26). These factors combine to reduce the suitability 
of the habitat for species like Arctic grayling (Hubert 1985, entire).
    Currently, restoration of riparian areas in the upper Big Hole 
River system is a priority under the CCAA (for more specific 
information, see ``Conservation Efforts to Reduce Habitat Destruction, 
Modification, or Curtailment of Its Range,'' below). Since 2006, 
efforts to restore and conserve riparian habitats have been numerous 
and multi-faceted (see Table 4). About 170 miles (274 km) of riparian 
habitat are currently enrolled in the Big Hole CCAA, out of a total of 
about 340 miles (547 km) of total riparian habitat in the CCAA 
Management Area. Of the enrolled riparian habitat, 65 percent (110 
miles (177 km)) is improving in condition, as rated by a standardized 
riparian protocol (NRCS 2004, entire). Further, 47 percent of enrolled 
riparian habitat (80 miles (129 km)) is functioning at a sustainable 
level, which is a 15 percent increase in 5 years (MTFWP et al. 2006, p. 
92; see Table 4). A sustainable rating indicates that the stream can 
access its flood plain, transport its sediment load, build banks, store 
water, and dissipate flood energy in conjunction with a healthy 
riparian zone (NRCS 2004, p. 7). Riparian habitats are reassessed every 
5 years and are scored on 10 stability and sustainability metrics (for 
example, stream incisement), with any reach scoring at 80 percent or 
above rated as sustainable (NRCS 2004, entire). In addition, adaptive 
management within the CCAA framework will allow for reevaluation of 
conservation measures being implemented in non-improving habitat.
    Other populations: In the Centennial Valley, historical livestock 
grazing both within the Red Rock Lakes NWR and on adjacent private 
lands negatively affected the condition of riparian habitats on 
tributaries to the Red Rock Lakes (Mogen 1996, pp. 75-77; Gillin 2001, 
pp. 3-12, 3-14). In general, degraded riparian habitat limits the 
creation and maintenance of aquatic habitats, especially pools, which 
are preferred habitats for adult Arctic grayling (Lamothe and Magee 
2004, pp. 21-22; Hughes 1992, entire), although many spawning adult 
Arctic grayling in Red Rock Creek outmigrate soon after spawning and 
likely do not use available pool habitat (Jordan 2014, pers. comm.). 
Loss of riparian vegetation

[[Page 49403]]

increases bank erosion, which can lead to siltation of spawning 
gravels, which may in turn harm Arctic grayling by reducing the extent 
of suitable spawning habitat and reducing survival of Arctic grayling 
embryos already present in the stream gravels.
    Recently, the Red Rock Lakes NWR acquired land on Red Rock Creek, 
upstream of the refuge boundary (West 2014a, pers. comm.). Much of this 
parcel was riparian habitat that was historically heavily grazed; thus, 
the refuge implemented a rest-rotation grazing system where more 
durable lands are grazed while more sensitive lands (e.g., riparian 
areas) are rested for up to 4 years. On average, grazing intensities on 
the refuge have decreased from 20,000 Animal Unit Months (AUMs, number 
of cow/calf pairs multiplied by the number of months grazed) to about 
5,000 AUMs. As a result of these changes, riparian habitat within the 
refuge has dramatically improved (West 2014b, pers. comm.) and is 
expected to continue improving under the new grazing regime. Concurrent 
with riparian improvement within Red Rock Lakes NWR, the number of 
adult Arctic grayling migrating up Red Rock Creek to spawn has 
increased from fewer than 500 to more than 2,000 (Patterson 2014, 
unpublished data). Given the riparian improvements within Red Rock 
Lakes NWR, and that the refuge represents the vast majority of current 
Arctic grayling habitat in the Centennial Valley, the effects of 
degraded riparian habitat do not appear to be acting on the core of the 
Centennial Valley population at the individual or population level.
    Most of the riparian habitat surrounding high-elevation lakes on 
Federal land where the remaining populations are found is intact and of 
high quality (MFISH 2014a, unpublished data; MFWP 2014e, unpublished 
data; USFS 2014, p. 2), because these habitats are in remote locations 
or wilderness areas with little anthropogenic disturbance. Given that 
riparian degradation is being systematically addressed in the Big Hole 
River and Centennial Valley on the National Refuge land where the 
majority of Arctic grayling reside, we conclude that riparian 
degradation is not a current threat to the DPS. Riparian habitat is 
expected to remain intact on Federal land because of existing 
regulatory mechanisms (see in Factor D discussion, below). Riparian 
habitat in the Big Hole River is expected to continue improving because 
of the proven track record of conservation evidenced by the current 
upward trend in riparian habitat quality. As more site-specific plans 
are signed under the Big Hole CCAA, more riparian improvement is 
expected because conservation measures will be similar between 
currently implemented and future site-specific plans. Given that 
riparian habitat is intact or improving for populations of Arctic 
grayling occurring on Federal land and the Big Hole population, and 
these populations account for 19 of 20 populations in the DPS, we 
conclude riparian habitat degradation is not a current rangewide threat 
and is not expected to become a threat in the future.
Dewatering From Irrigation and Consequent Increased Water Temperatures
    Demand for irrigation water in the semi-arid upper Missouri River 
basin historically dewatered many rivers formerly or currently occupied 
by Arctic grayling. The primary effects of this dewatering were: (1) 
Increased water temperatures, and (2) reduced habitat capacity. In 
ectothermic species like salmonid fishes, water temperature sets basic 
constraints on species' distribution and physiological performance, 
such as activity and growth (Coutant 1999, pp. 32-52). Increased water 
temperatures can reduce the growth and survival of Arctic grayling 
(physiological stressor). Reduced habitat capacity can concentrate 
fishes and thereby increase competition and predation (ecological 
stressor). Below we discuss the potential effects of increased water 
temperature on the Upper Missouri River DPS of Arctic grayling. For 
discussion of the potential effects of reduced habitat capacity, see 
Cumulative Effects from Factors A through E, below.
    Big Hole: In the Big Hole River system, surface-water (flood) 
irrigation has altered the natural hydrologic function of the river 
(Shepard and Oswald 1989, p. 29; Byorth 1993, p. 14; 1995, pp. 8-10; 
Magee et al. 2005, pp. 13-15). An inverse relationship between flow 
volume and water temperature (i.e., lower flows can lead to higher 
water temperatures) is apparent in the Big Hole River (Flynn et al. 
2008, pp. 44, 46, but see Sladek 2013, p. 31). Summer water 
temperatures exceeding 21 [deg]C (70 [deg]F) are considered to be 
physiologically stressful for cold-water fish species, such as Arctic 
grayling (Hubert et al. 1985, pp. 7, 9). Summer water temperatures 
consistently exceed 21 [deg]C (70 [deg]F) in the mainstem of Big Hole 
River (Cayer and McCullough 2012, p. 7; (Cayer and McCullough 2013, p. 
6) and have exceeded the upper incipient lethal temperature (UILT; the 
temperature that is survivable for periods longer than 1 week by 50 
percent of a ``test population'' in an experimental setting) for Arctic 
grayling (e.g., 25 [deg]C or 77 [deg]F) (Lohr et al. 1996). As a 
result, thermal fish kills have been documented in the Big Hole River 
(Lohr et al. 1996, p. 934) in the past. The most recent fish kill in 
the Big Hole River that we are aware of occurred in 1994, and included 
eight fish species, including Arctic grayling (Lohr et al. 1996, p. 
934).
    Arctic grayling in the Big Hole River use tributaries as a thermal 
refuge when summer water temperatures in the mainstem become stressful 
(Vatland et al. 2009, p. 11). Summer water temperatures within most 
tributaries are cooler than those observed in some reaches of the 
mainstem Big Hole River (Vatland et al. 2009, entire; MFWP 2014b, 
unpublished data).
    Since 2006, water conservation and restoration projects associated 
with the Big Hole Arctic grayling CCAA (for more specific information, 
see ``Conservation Efforts to Reduce Habitat Destruction, Modification, 
or Curtailment of Its Range,'' below) have been implemented to increase 
instream flows and reduce water temperatures in the Big Hole River and 
tributaries. Varying flow targets for different management segments of 
the Big Hole River were outlined in the CCAA, based on the wetted 
perimeter method, a biologically based method for determining instream 
flow requirements to provide necessary resources for all life stages of 
Arctic grayling. Over 300 irrigation diversions are operated under flow 
agreements within finalized site-specific plans (Table 4). The 10 
remaining site-specific plans representing the remainder of points of 
diversion are expected to be signed in August 2014. Although we are 
aware of the future potential of more points of diversion being managed 
under signed site plans to contribute to Arctic grayling conservation, 
we do not consider these anticipated future efforts to contribute to 
Arctic grayling conservation currently, and have not considered them as 
part of this status review or our listing determination for this DPS. 
Multiple other projects designed to decrease dewatering and thermal 
stress have been implemented since 2006 (Table 4). The collective 
result of these efforts are increasing streamflows, increased access to 
cold-water refugia via fish ladders, and marked temperature reductions, 
particularly in some tributaries (Table 4).
    Specific flow targets were developed for the different Management 
Segments in the CCAA Management Area (see MFWP et al. 2006, pp. 7, 9, 
13, for more information on CCAA Management

[[Page 49404]]

Segments). The goal for increasing instream flow was to achieve flow 
targets 75 percent of days in each Management Segment during years of 
average or greater snowpack. This goal was based on a comparison 
between minimum flow targets and historical streamflows recorded in 
Management Segments C and D. Achieving flow targets 75 percent of days 
in each Management Segment was intended to be a general goal because 
many other factors influence instream flows in the Big Hole River that 
are outside the control of landowners (e.g., snowpack, precipitation). 
Before implementation of the CCAA (2000-2005), average flow targets 
were met among all Management Segments 50 percent of the time, and 
since implementation of the CCAA (2006-2012), they have been met 78 
percent of the time (SHCP 2013, p. 12). Thus, the targets are being 
met.
    Consistently since 2006, one management area, known as Management 
Segment C, has exhibited the lowest instream flows among all Management 
Segments. In part, instream flows in Management Segment C are 
influenced by several large diversions immediately upstream of the flow 
measuring device at the downstream boundary of Management Segment C 
(Robert 2014, pers. comm.). Some of this diverted water is returned to 
the Big Hole River downstream of the flow measuring device (Robert 
2014, pers. comm.). As such, instream flows in Management Segment C 
represent the ``worst case'' scenario among all Management Segments. 
The Montana Department of Natural Resources and Conservation conducted 
an analysis of this ``worst case'' scenario, to explore how instream 
flows in Management Segment C have changed since the inception of the 
Big Hole CCAA. Given that natural factors such as summer precipitation 
and annual snowpack influence instream flows in the Big Hole River, the 
analysis of instream flows in Management Segment C included comparisons 
among several years of similar (but below average) snow pack and 
similar summer precipitation, both before and after CCAA implementation 
(Table 5).

Table 5--Comparison of Number of Days Varying Flow Targets Were Achieved
Among Similar Years of Below Average Snowpack in the Big Hole River CCAA
 Management Segment C, Pre- and Post CCAA. All Information in This Table
                Cited From Roberts 2014, Unpublished Data
------------------------------------------------------------------------
                                          Pre-CCAA          Post-CCAA
                                     -----------------------------------
                                        1988     2003     2012     2013
------------------------------------------------------------------------
Peak snowpack (percent of average)..    \a\73      108       81    \a\75
May-Aug. precipitation (in.)........     4.14     3.85     4.74     5.14
July-Aug. temps (degrees F;              -1.3      8.0      1.4      1.9
 departure from normal).............
Signed SSPs.........................        0        0       12       15
Landowner contributions (cfs).......        0        0      252      260
Days <160 \b\ cfs...................       50        8       11       40
Days <60 \b\ cfs....................      123      123       87       69
Days <20 cfs........................       79       68        0       28
Days <10 cfs........................       65        7        0        1
Mean discharge (cfs; July-Sept.)....      8.4     19.7       45       39
Mean discharge (cfs; Aug.)..........      1.1     14.2     33.7       21
                                     -----------------------------------
    Total Days 60 years) with no observed declines in abundance.
Predation by Birds and Mammals
    In general, the incidence and effect of predation by birds and 
mammals on Arctic grayling is not well understood because few detailed 
studies have been completed (Northcote 1995, p. 163). Black bear (Ursus 
americanus), mink (Neovison vison), and river otter (Lontra canadensis) 
are present in southwestern Montana, but direct evidence of predatory 
activity by these species is often lacking (Kruse 1959, p. 348). Osprey 
(Pandion haliaetus) can capture Arctic grayling during the summer 
(Kruse 1959, p. 348). In the Big Hole River, Byorth and Magee (1998, p. 
926) attributed the loss of Arctic grayling from artificial enclosures 
used in a competition experiment to predation by minks, belted 
kingfisher (Ceryle alcyon), osprey, and great blue heron (Ardea 
herodia). In addition, American white pelican (Pelecanus 
erythrorhynchos) are seasonally present in the Big Hole River, and they 
also may feed on Arctic grayling. The aforementioned mammals and birds 
can be effective fish predators; however, Arctic grayling evolved with 
these native predator species and have developed life-history and 
reproductive strategies to mitigate for predation losses. We have no 
data demonstrating any of these species historically or currently 
consume Arctic grayling at levels sufficient to exert a measureable, 
population-level impact on native Arctic grayling in the upper Missouri 
River system. We expect the current situation to continue, so we 
conclude that predation by birds and mammals does not constitute a 
threat to Missouri River Arctic grayling now or in the future.
Summary of Factor C
    Based on the information available at this time, we conclude 
disease does not represent a past or current threat to the Upper 
Missouri River DPS of Arctic grayling. We have no basis for concluding 
that disease may become a future threat.
    Predation and competition can influence the distribution, 
abundance, and diversity of species in ecological communities. 
Predation by and competition with nonnative species can negatively 
affect native species, particularly those that are stressed or 
occurring at low densities due to unfavorable environmental conditions. 
Historically, the impact of predation and competition from nonnatives 
was likely greater because many of the habitats used by Arctic grayling 
were degraded. Thus, predation and competition likely played a role 
historically in decreasing the abundance and distribution of Arctic 
grayling. Currently, habitat conditions have improved markedly for 
those Arctic grayling populations on Federal land (18 of 20 
populations) and for the Big Hole River population on primarily private 
land. Predation and competition with nonnative species are still 
occurring in these systems, although the extent and magnitude of these 
effects appears to be mediated by habitat quality. Abundance of Arctic 
grayling and nonnative brown trout are increasing in the Big Hole 
River. Before suppression efforts began, Yellowstone cutthroat hybrids 
and Arctic grayling spawners were both at 40 year highs in Red Rock 
Creek in the Centennial Valley. We acknowledge nonnative trout 
densities are high in the Madison River and may be contributing to the 
decline of that Arctic grayling population; however, most other 
adfluvial populations appear to have stable abundance of Arctic 
grayling and nonnatives. Thus, based on our review we have no 
information that predation or competition represents a threat at the 
DPS level on the Upper Missouri River DPS of Arctic grayling. Further, 
Arctic grayling experts project only a small effect of predicted 
nonnative trout densities on Arctic grayling recruitment in the future. 
Thus, we have no information that predation or competition from 
nonnative trout represents a future threat at the population or species 
level.
    Little is known about the effect of predation on Arctic grayling by 
birds and mammals. Such predation likely does occur, but we are not 
aware of any situation where an increase in fish-eating birds or 
mammals has coincided with the decline of Arctic grayling. 
Consequently, the available information does not support a conclusion 
that predation by birds or mammals represents a substantial past, 
present, or future threat to native Arctic grayling in the upper 
Missouri River.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

    Section 4(b)(1)(A) of the Act requires the Service to take into 
account ``those efforts, if any, being made by any State or foreign 
nation, or any political subdivision of a State or foreign nation, to 
protect such species . . .'' We consider relevant Federal, State, and 
Tribal laws, and regulations when evaluating the status of the species. 
Regulatory mechanisms, if they exist, may preclude the need for listing 
if we determine that such mechanisms adequately address the threats to 
the species such that listing is not warranted. Only existing 
ordinances, regulations, and laws, that have a direct connection to a 
law, are enforceable and permitted are discussed in this section. All 
other measures are discussed under the specific relevant factor.
U.S. Federal Laws and Regulations
    No Federal laws in the United States specifically address the 
Arctic grayling, but several, in their implementation, may affect the 
species' habitat.
National Environmental Policy Act
    All Federal agencies are required to adhere to the National 
Environmental Policy Act (NEPA) of 1970 (42 U.S.C. 4321 et seq.) for 
projects they fund, authorize, or carry out. The Council on 
Environmental Quality's regulations for implementing NEPA (40 CFR parts 
1500-1518) state that, when preparing environmental impact statements, 
agencies shall include a discussion on the environmental impacts of the 
various project alternatives, any adverse environmental effects which 
cannot be avoided, and any irreversible or irretrievable commitments of 
resources involved (40 CFR part 1502). The NEPA itself is a disclosure 
law, and does not require subsequent minimization or mitigation 
measures by the Federal agency involved. Although Federal agencies may 
include conservation measures for Arctic grayling as a result of the 
NEPA process, any such measures are typically voluntary in nature and 
are not required by NEPA.

[[Page 49415]]

Federal Land Policy and Management Act
    The Federal Land Policy and Management Act (FLPMA) of 1976 (43 
U.S.C. 1701 et seq.), as amended, states that the public lands shall be 
managed in a manner that will protect the quality of scientific, 
scenic, historical, ecological, environmental, air and atmospheric, 
water resource, and archeological values. This statute protects lands 
within the range of the Arctic grayling managed by the Bureau of Land 
Management (BLM).
    The BLM considers the fluvial Arctic grayling a sensitive species 
requiring special management consideration for planning and 
environmental analysis (BLM 2009a, entire, BLM 2009b, entire). The BLM 
has recently developed a resource management plan (RMP) for the Dillon 
Field Office Area that provides guidance for the management of over 
900,000 acres of public land administered by BLM in southwest Montana 
(BLM 2006a, p. 2). The Dillon RMP area thus includes the geographic 
area that contains the Big Hole, Miner, Mussigbrod, Madison River, and 
Centennial Valley populations of Arctic grayling. A RMP planning area 
encompasses all private, State, and Federal lands within a designated 
geographic area (BLM 2006a, p. 2), but the actual implementation of the 
RMP focuses on lands administered by the BLM that typically represent 
only a fraction of the total land area within that planning area (BLM 
2006b, entire). Restoring Arctic grayling habitat and ensuring the 
long-term persistence of both fluvial and adfluvial ecotypes are among 
the RMP's goals (BLM 2006a, pp. 30-31). However, there is little actual 
overlap between the specific parcels of BLM land managed by the Dillon 
RMP and the current distribution of Arctic grayling (BLM 2006b, 
entire).
    The BLM also has a RMP for the Butte Field Office Area, which 
includes more than 300,000 acres in south-central Montana (BLM 2008, 
entire), including portions of the Big Hole River in Deerlodge and 
Silver Bow counties (BLM 2008, p. 8; 2009c, entire). The Butte RMP 
considers conservation and management strategies and agreements for 
Arctic grayling in its planning process and includes a goal to 
opportunistically enhance or restore habitat for Arctic grayling (BLM 
2008, pp. 10, 30, 36). However, the Butte RMP does not mandate specific 
actions to improve habitat for Arctic grayling in the Big Hole River 
and little overlap exists between BLM-managed lands and Arctic grayling 
occupancy in this planning area.
National Forest Management Act
    Under the U.S. Forest Service (USFS) National Forest Management Act 
(NFMA) of 1976, as amended (16 U.S.C. 1600 et seq.), the USFS strives 
to provide for a diversity of plant and animal communities when 
managing national forest lands. Individual national forests may 
identify species of concern that are significant to each forest's 
biodiversity. The USFS considers fluvial Arctic grayling a sensitive 
species (USFS 2004, entire) for which population viability is a 
concern. However, this designation provides no special regulatory 
protections.
    Most of the upper Missouri River grayling populations occur on 
National Forest land; all 16 adfluvial populations and the fluvial Ruby 
River population (majority on National Forest) occur on USFS-managed 
lands. These populations occur across four different National Forests; 
consequently the riparian habitats surrounding the lakes and 
tributaries are managed according to the standards and guidelines 
outlined in each National Forest Plan. All Forest Plans do not contain 
the same standards and guidelines; however, each Plan has standards and 
guidelines for protecting riparian areas around perennial water 
sources. In the Beaverhead-Deerlodge and Helena National Forest Plans, 
the Inland Native Fish Strategy (INFS) standards and guidelines have 
been incorporated. The INFS, in part, defines widths of riparian buffer 
zones adequate to protect streams and lakes from non-channelized 
sediment inputs and contribute to other riparian functions, such as 
stream shading and bank stability. These protections have been 
incorporated into the Beaverhead-Deerlodge and Helena National Forest 
Plans through amendments and are currently preserving intact riparian 
areas around most, if not all, adfluvial Arctic grayling habitats. 
Exceptions to the riparian protections outlined in INFS are 
occasionally granted; however, these exceptions require an analysis of 
potential effects and review by a USFS fish biologist.
    On the Gallatin National Forest, standards and guidelines in the 
Forest Plan include using ``best management practices (BMPs)'' to 
protect water sources and riparian areas. Similar to INFS, BMPs outline 
buffer strips along watercourses where disturbance and activity is 
minimized to protect riparian areas and water quality. On the Lewis and 
Clark National Forest, standards and guidelines are in place to leave 
timbered buffer strips adjacent to waterbodies to protect riparian 
areas. Grayling habitat on the Gallatin and Lewis and Clark National 
Forests consists of seven high-elevation mountain lakes.
    The NFMA and INFS are adequately protecting riparian habitat on 
National Forest land, given the intact nature of most riparian areas 
surrounding the high-elevation lake populations and the Ruby River.
National Park Service (NPS) Organic Act
    The NPS Organic Act of 1916 (16 U.S.C. 1 et seq.), as amended, 
states that the NPS ``shall promote and regulate the use of the Federal 
areas known as national parks, monuments, and reservations . . . to 
conserve the scenery and the national and historic objects and the wild 
life therein and to provide for the enjoyment of the same in such 
manner and by such means as will leave them unimpaired for the 
enjoyment of future generations.'' Arctic grayling are native to the 
western part of Yellowstone National Park and habitats are managed 
accordingly for the species under the Native Species Management Plan 
(NPS 2010, entire). One adfluvial Arctic grayling population, Grebe 
Lake, currently occurs in Yellowstone National Park. The Grebe Lake 
population is one of the larger adfluvial populations (see Table 3, 
above) in the DPS. The habitat in Grebe Lake and the tributaries is 
managed for conservation (NPS 2010, p. 44). Further, it is expected 
that these habitats will be managed for conservation in the future, 
based on provisions in the Organic Act and guidance outlined in the 
Native Species Management Plan.
National Wildlife Refuge System Improvement Act of 1997
    The National Wildlife Refuge Systems Improvement Act (NWRSIA) of 
1997 (Pub. L. 105-57) amends the National Wildlife Refuge System 
Administration Act of 1966 (16 U.S.C. 668dd et seq.). The NWRSIA 
directs the Service to manage the Refuge System's lands and waters for 
conservation. The NWRSIA also requires monitoring of the status and 
trends of refuge fish, wildlife, and plants. The NWRSIA requires 
development of a comprehensive conservation plan (CCP) for each refuge 
and management of each refuge consistent with its plan.
    The Service has developed a final CCP to provide a foundation for 
the management and use of Red Rock Lakes NWR (USFWS 2009, entire) in 
the Centennial Valley. Since the development of the CCP, Refuge staff 
have conducted numerous habitat conservation/restoration projects to 
benefit Arctic grayling, including:

[[Page 49416]]

Removal of an earthen dam whose reservoir inundated several hundred 
meters of historical Arctic grayling spawning habitat in Elk Springs 
Creek, and subsequent reintroductions and tracking of young-of-year 
Arctic grayling in Elk Springs Creek (West 2014a, pers. comm.). However 
to date, the reintroductions in Elk Springs Creek have not established 
a spawning run. Other conservation projects conducted on the Refuge 
include the acquisition of new land and decreases in grazing 
intensities from 20,000 AUMs to about 5,000 AUMs. The Refuge has 
implemented a rest-rotation grazing system where more durable lands are 
grazed while more sensitive lands (e.g., riparian areas) are rested for 
up to 4 years (West 2014a, pers. comm.). Some active riparian 
restoration has also occurred, including a project to reconnect Red 
Rock Creek to a historical channel and replacement of four culverts to 
allow for natural tributary migration across alluvial fans (West 2014a, 
pers. comm.). The Refuge is also actively engaged in supporting ongoing 
graduate research efforts to explore potential limiting factors for 
Arctic grayling in the Centennial Valley.
    Other conservation projects under the CCP have been focused on 
potential nonnative species effects on Arctic grayling, namely a 5-year 
project removing hybrid cutthroat trout captured during their upstream 
spawning run and a study of dietary overlap between Arctic grayling and 
Yellowstone cutthroat trout (West 2014a, pers. comm.). The Refuge also 
operates a sill dam (previous upstream fish barrier) to provide 
upstream fish passage and operates one irrigation ditch only when 
snowpack is average or above and timing is such that young Arctic 
grayling are not present near the diversion (West 2014a, pers. comm.).
    The NWRSIA is adequately protecting habitat for Arctic grayling on 
the Refuge because riparian habitats are improving and the Centennial 
Valley population is increasing in both abundance and distribution. The 
proven track record of completed conservation projects on the refuge 
and currently expanding Arctic grayling population indicate that the 
continued implementation of the CCP during the next 15 years (which is 
the life of the CCP) will continue to improve habitat conditions on the 
refuge.
Federal Power Act (FPA)
    The Federal Power Act of 1920 (16 U.S.C. 791 et seq., as amended) 
provides the legal authority for the Federal Energy Regulatory 
Commission (FERC), as an independent agency, to regulate hydropower 
projects. In deciding whether to issue a license, FERC is required to 
give equal consideration to mitigation of damage to, and enhancement 
of, fish and wildlife (16 U.S.C. 797(e)). A number of FERC-licensed 
dams exist in the Missouri River basin in current (i.e., Ennis Dam on 
the Madison River) and historical Arctic grayling habitat (e.g., Hebgen 
Dam on the Madison River; Hauser, Holter, and Toston dams on the 
mainstem Missouri River; and Clark Canyon Dam on the Beaverhead River). 
The FERC license expiration dates for these dams range from 2024 
(Toston) to 2059 (Clark Canyon) (FERC 2010, entire). None of these 
structures provides upstream passage of fish, and such dams are 
believed to be one of the primary factors that led to the historical 
decline of Arctic grayling in the Missouri River basin (see discussion 
under Factor A, above). However, recent monitoring data indicate 
multiple stable Arctic grayling populations occurring above mainstem 
dams, with the exception of the Ennis Reservoir/Madison River 
population. The drawdowns in reservoir water level believed to have 
historically affected the Ennis Reservoir/Madison River Arctic grayling 
population are not permitted under a new licensing agreement between 
the Federal Energy Regulatory Commission and Madison Dam operators, as 
we described previously in this finding (Clancey 2014, pers. comm.). 
This change in water management in Ennis Reservoir will ensure adequate 
rearing and foraging habitat for this population. The fluvial ecotype 
is still represented in the DPS and both strictly fluvial Arctic 
grayling populations appear to be stable or increasing. Thus, we 
conclude the Federal Power Act is currently adequate to protect the 
Upper Missouri River DPS of Arctic grayling at the population and DPS 
level.
Clean Water Act
    The Clean Water Act (CWA) of 1972 (33 U.S.C. 1251 et seq.) 
establishes the basic structure for regulating discharges of pollutants 
into the waters of the United States and regulating quality standards 
for surface waters. The CWA's general goal is to ``restore and maintain 
the chemical, physical, and biological integrity of the Nation's 
waters'' (33 U.S.C. 1251(a)). The CWA requires States to adopt 
standards for the protection of surface water quality and establishment 
of total maximum daily load (TMDL) guidelines for rivers. The Big Hole 
River has approved TMDL plans for its various reaches (MDEQ 2009a, 
entire; 2009b, entire); thus, complete implementation of this plan 
should improve water quality (by reducing water temperatures, and 
reducing sediment and nutrient inputs) in the Big Hole River in the 
future. As of September 2013, there was no significant TMDL plan 
development activity in the Madison River or Red Rock watershed in the 
Centennial Valley (see MDEQ 2014). Currently, TMDL documents have been 
approved for the Ruby River. All planning areas containing other 
adfluvial Arctic grayling populations in the upper Missouri River basin 
have approved TMDLs, including the Gallatin, Lake Helena, and Sun 
watersheds (see MDEQ 2014).
    Currently, water temperatures in the Big Hole River exceed levels 
outlined in the TMDL. However, reductions in water temperature within 
tributaries have been demonstrated (see discussion under Factor A and 
Table 4). Given that most Arctic grayling populations within the upper 
Missouri River basin are stable or increasing and habitats are largely 
being managed in a manner that benefits the species, we have no 
evidence that the CWA is inadequately protecting Arctic grayling at the 
population or DPS level.
State Laws
Montana Environmental Policy Act
    The legislature of Montana enacted the Montana Environmental Policy 
Act (MEPA) as a policy statement to encourage productive and enjoyable 
harmony between humans and their environment, to protect the right to 
use and enjoy private property free of undue government regulation, to 
promote efforts that will prevent or eliminate damage to the 
environment and biosphere and stimulate the health and welfare of 
humans, to enrich the understanding of the ecological systems and 
natural resources important to the State, and to establish an 
environmental quality council (MCA 75-1-102). Part 1 of the MEPA 
establishes and declares Montana's environmental policy. Part 1 has no 
legal requirements, but the policy and purpose provide guidance in 
interpreting and applying statutes. Part 2 requires State agencies to 
carry out the policies in Part 1 through the use of systematic, 
interdisciplinary analysis of State actions that have an impact on the 
human environment. This is accomplished through the use of a 
deliberative, written environmental review. In practice, MEPA provides 
a basis for the adequate review of State actions in order to ensure 
that environmental concerns are fully considered (MCA 75-1-102). 
Similar to NEPA, the MEPA is largely a disclosure

[[Page 49417]]

law and a decision-making tool that does not specifically require 
subsequent minimization or mitigation measures.
Laws Affecting Physical Aquatic Habitats
    A number of Montana State laws have a permitting process applicable 
to projects that may affect stream beds, river banks, or floodplains. 
These include the Montana Stream Protection Act (SPA), the Streamside 
Management Zone Law (SMZL), and the Montana Natural Streambed and Land 
Preservation Act (Montana Department of Natural Resources (MDNRC) 2001, 
pp. 7.1-7.2). The SPA requires that a permit be obtained for any 
project that may affect the natural and existing shape and form of any 
stream or its banks or tributaries (MDNRC 2001, p. 7.1). The Montana 
Natural Streambed and Land Preservation Act (i.e., MNSLPA or 310 
permit) requires private, nongovernmental entities to obtain a permit 
for any activity that physically alters or modifies the bed or banks of 
a perennially flowing stream (MDNRC 2001, p. 7.1). The SPA and MNSLPA 
laws do not mandate any special recognition for species of concern, but 
in practice, biologists that review projects permitted under these laws 
usually stipulate restrictions to avoid harming such species (Horton 
2010, pers. comm.). The SMZL regulates forest practices near streams 
(MDNRC 2001, p. 7.2). The Montana Pollutant Discharge Elimination 
System (MPDES) Stormwater Permit applies to all discharges to surface 
water or groundwater, including those related to construction, 
dewatering, suction dredges, and placer mining, as well as to 
construction that will disturb more than 1 acre within 100 ft (30.5 m) 
of streams, rivers, or lakes (MDNRC 2001, p. 7.2).
    Review of applications by MFWP, MTDEQ, or MDNRC is required prior 
to issuance of permits under the above regulatory mechanisms (MDNRC 
2001, pp. 7.1-7.2). These regulatory mechanisms are expected to limit 
impacts to aquatic habitats in general. Given that most Arctic grayling 
populations are stable or increasing in abundance in the presence of 
these regulatory mechanisms, we have no basis for concluding that these 
regulatory mechanisms are inadequate to protect the Arctic grayling and 
their habitat now or in the future.
Montana Water Use Act
    The purpose of the Montana Water Use Act (Title 85: Chapter 2, 
Montana Codes Annotated) is to provide water for existing and future 
beneficial use and to maintain minimum flows and water quality in 
Montana's streams. The Missouri River system is generally believed to 
be overappropriated, and water for additional consumptive uses is only 
available for a few months during very wet years (MDNRC 1997, p. 12). 
However, the upper Missouri River basin and Madison River basin have 
been closed to new water appropriations because of water availability 
problems, overappropriation, and a concern for protecting existing 
water rights (MDNRC 2009, p. 45). In addition, recent compacts (a legal 
agreement between Montana, a Federal agency, or an Indian tribe 
determining the quantification of federally or tribally claimed water 
rights) have been signed that close appropriations in specific waters 
in or adjacent to Arctic grayling habitats. For example, the USFWS-Red 
Rock Lakes-Montana Compact includes a closure of appropriations for 
consumptive use in the drainage basins upstream of the most downstream 
point on the Red Rock Lakes NWR and the Red Rock Lakes Wilderness Area 
(MDNRC 2009, pp. 18, 47). The NPS-Montana Compact specifies that 
certain waters will be closed to new appropriations when the total 
appropriations reach a specified level, and it applies to Big Hole 
National Battlefield and adjacent waters (North Fork of the Big Hole 
River and its tributaries including Ruby and Trail Creeks), and the 
portion of Yellowstone National Park that is in Montana (MDNRC 2009, p. 
48).
    The State of Montana is currently engaged in a Statewide effort to 
adjudicate (finalize) water rights claimed before July 1, 1973. The 
final product of adjudication in a river basin is a final decree. To 
reach completion, a decree progresses through several stages: (1) 
Examination, (2) temporary preliminary decree, (3) preliminary decree, 
(4) public notice, (5) hearings, and (6) final decree (MDNRC 2009, pp. 
9-14). As of February 2014, the Centennial Valley has a preliminary 
decree, and the Big Hole and Madison Rivers have preliminary temporary 
decrees (MDNRC 2014, entire). We anticipate the final adjudication of 
all the river basins in Montana that currently contain native Arctic 
grayling will be completed in the next 5 years, but we do not know if 
this process will eliminate the overallocation of water rights. We note 
that the overallocation of water in some systems within the upper 
Missouri river basin is of general concern to Arctic grayling because 
of the species' need for adequate quantity and quality of water for all 
life stages. However, we have no information indicating that 
overallocation of water in the upper Missouri River basin is a current 
threat at the individual or DPS level because most populations are 
stable or increasing at this time. Therefore, we conclude that the 
Montana Water Use Act is adequate to protect the Arctic grayling and 
its habitat.
Angling Regulations
    Arctic grayling is considered a game fish (MFWP 2010, p. 16), but 
is subject to special catch-and-release regulations in streams and 
rivers within its native range, as was described under Factor B, above 
(MFWP 2014d, p. 51). Catch-and-release regulations also are in effect 
for Ennis Reservoir on the Madison River and Red Rock Creek in the 
Centennial Valley (MFWP 2014d, p. 63). Arctic grayling in other 
adfluvial populations are subject to more liberal regulations; anglers 
can keep up to 5 per day and have up to 10 in possession in accordance 
with standard daily and possession limits for that angling management 
district (MFWP 2014d, p. 51). We have no evidence to indicate that 
current fishing regulations are inadequate to protect native Arctic 
grayling in the Missouri River basin (see discussion under Factor B, 
above).
Summary of Factor D
    Current Federal and State regulatory mechanisms are adequate to 
protect Arctic grayling of the upper Missouri River. We conclude this 
because the majority of populations are on Federal land where 
regulatory mechanisms are in place to preserve intact habitats and are 
expected to remain in place. In the Big Hole River, fluvial Arctic 
grayling generally occupy waters adjacent to private lands (MFWP et al. 
2006, p. 13; Lamothe et al. 2007, p. 4), so Federal regulations may 
have limited ability to protect that population. However, some Federal 
regulations (e.g., CWA, FPA, NMFA, NWRSIA, NPS Organic Act) in concert 
with other existing conservation efforts (e.g., Big Hole CCAA) are 
adequate to sustain and improve habitat conditions for Arctic grayling. 
Arctic grayling in the Big Hole River appear to be responding 
positively to these improvements. In addition, we did not identify 
other threats to the DPS that would require regulatory protections.
    For the reasons described above, we conclude that existing 
regulatory mechanisms are adequate to protect the Upper Missouri River 
DPS of Arctic grayling. We do not anticipate any changes to the 
existing regulatory mechanisms; thus we conclude that existing 
regulatory mechanisms will remain adequate in the future.

[[Page 49418]]

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

Drought
    Drought is a natural occurrence in the interior western United 
States (see National Drought Mitigation Center 2010). The duration and 
severity of drought in Montana appears to have increased during the 
last 50 years, and precipitation has tended to be lower than average in 
the last 20 years (National Climatic Data Center 2010). Drought can 
affect fish populations by reducing stream flow volumes. This leads to 
dewatering and high temperatures that can limit connectivity among 
spawning, rearing, and sheltering habitats. Drought can also reduce the 
volume of thermally suitable habitat and increase the frequency of 
water temperatures above the physiological limits for optimum growth 
and survival in Arctic grayling. In addition, drought can interact with 
human-caused stressors (e.g., irrigation withdrawals, riparian habitat 
degradation) to further reduce stream flows and increase water 
temperatures.
    Reduced stream flows and elevated water temperatures during drought 
have been most apparent in the Big Hole River system (Magee and Lamothe 
2003, pp. 10-14; Magee et al. 2005, pp. 23-25; Rens and Magee 2007, pp. 
11-12, 14). In the Big Hole River, evidence for the detrimental effects 
of drought on Arctic grayling populations is primarily inferential; 
observed declines in fluvial Arctic grayling and nonnative trout 
abundances in the Big Hole River coincide with periods of drought 
(Magee and Lamothe 2003, pp. 22-23, 28) and fish kills (Byorth 1995, 
pp. 10-11, 31).
    Although the response of stream and river habitats to drought is 
expected to be most pronounced because of the strong seasonality of 
flows in those habitats, effects in lake environments can occur. For 
example, both the Upper and Lower Red Rock Lakes are very shallow 
(Mogen 1996, p. 7). Increased frequency or duration of drought could 
lead to increased warming in shallower lakes, such as Upper Red Rock 
Lake. However, the Centennial Valley has many springs sources that 
could, at least in part, mitigate for increases in water temperature 
due to increased drought frequency and magnitude. Other potential 
effects from drought could include a reduction in overall lake depth, 
which could in turn affect summer or overwintering habitat. Adfluvial 
populations in high mountain lakes would likely not be affected 
significantly by drought because air (and thus water) temperatures in 
these habitats are relatively cool due to the greater distance from sea 
level at high elevations (~ a 3.6 [deg]F (6.5 [deg]C) decrease in air 
temperature for every 3,200 ft. (1 kilometer) above sea level; Physics 
2014). In addition, most of these habitats are relatively large bodies 
of water volumetrically, thus are resistant to warming, given the high 
specific heat of water (USGS 2014). Further, intact riparian areas in 
these habitats buffer against water temperature increases in 
tributaries by blocking incoming solar radiation (Sridhar et al. 2004, 
entire; Cassie 2006, p. 1393).
    Given the climate of the intermountain West, we conclude that 
drought has been and will continue to be a natural occurrence. We 
assume that negative effects of drought on Arctic grayling populations, 
such as reduced connectivity among habitats or increased water 
temperatures at or above physiological thresholds for growth and 
survival, are more frequent in stream and river environments and in 
very shallow lakes relative to larger, deeper lakes. As discussed under 
Factor A, the implementation of the Big Hole Arctic grayling CCAA is 
likely to minimize some of the effects of drought in the Big Hole 
River, by reducing the likelihood that human-influenced actions or 
outcomes (irrigation withdrawals, destruction of riparian habitats, and 
fish passage barriers) will interact with the natural effects of 
drought (reduced stream flows and increased water temperatures). We 
expect the impact of drought may act at the individual level, but not 
at the population or DPS level because most grayling populations reside 
in drought-resistant habitats in high mountain lakes. Some populations 
will likely be affected by drought, but implemented conservation 
measures (Big Hole River population) and natural spring sources 
(Centennial Valley) are expected to minimize the impact. Overall, we 
conclude that drought has been a past threat when many historical 
habitats were degraded, but is not a current threat because of the 
intact nature of most habitats occupied by Arctic grayling in the upper 
Missouri River basin. Drought is expected to increase in both duration 
and severity in the future; however, resiliency currently being 
incorporated into riparian and aquatic habitats through conservation 
projects will likely buffer the effects of drought. Thus, drought is 
not expected to pose a threat to the DPS in the future.
Stochastic (Random) Threats, Genetic Diversity and Small Population 
Size
    A principle of conservation biology is that the presence of larger 
and more productive (resilient) populations can reduce overall 
extinction risk. To minimize extinction risk due to stochastic (random) 
threats, life-history diversity should be maintained, populations 
should not all share common catastrophic risks, and both widespread and 
spatially close populations are needed (Fausch et al. 2006, p. 23; 
Allendorf et al. 1997, entire).
    The Upper Missouri River DPS of Arctic grayling exists largely as a 
collection of isolated populations (Peterson and Ardren 2009, entire), 
with little to no gene flow among populations. While the inability of 
fish to move between populations limits genetic exchange and 
demographic support (Hilderbrand 2003, p. 257), large population sizes 
coupled with adequate number of breeding individuals minimize the 
effects of isolation. For example, Grebe Lake, a large population, 
receives no genetic infusion from any other population in the upper 
Missouri River basin, yet has a very large estimated effective 
population size (see Table 3, above). Loss of genetic diversity from 
genetic drift is not a concern for this population, despite it being 
reproductively isolated.
    Abundance among the 20 Arctic grayling populations varies widely 
(see Table 3, above). Individually, small populations like Ruby River 
need to maintain enough adults to minimize loss of variability through 
genetic drift and inbreeding (Rieman and McIntyre 1993, pp. 10-11). The 
point estimates of the effective number of breeders observed in all 
populations (where data are available) are above the level at which 
inbreeding is an immediate concern (Leary 2014, pers. comm.). The Ruby 
River population exhibits a low effective number of breeders, but 
contains the second highest genetic diversity among all populations 
(Leary 2014, unpublished data). Thus, inbreeding depression is probably 
not a concern for this population in the near future (Leary 2014, pers. 
comm.).
    Effective population size estimates for other Arctic grayling 
populations vary from 162 to 1,497 (see Table 3, above). There has been 
considerable debate about what effective population size is adequate to 
conserve genetic diversity and long-term adaptive potential (see 
Jamieson and Allendorf 2012 for review, p. 579). However, loss of 
genetic diversity is typically not an immediate threat even in isolated 
populations with an Ne >100 (Palstra and Ruzzante 2008, p. 
3441), but rather is a symptom of deterministic processes acting on the 
population (Jamieson and Allendorf

[[Page 49419]]

2012, p. 580). In other words, loss of genetic diversity due to small 
effective population size typically does not drive species to 
extinction (Jamieson and Allendorf 2012, entire); other processes, such 
as habitat degradation, have a more immediate and greater impact on 
species persistence (Jamieson and Allendorf 2012). We acknowledge that 
loss of genetic diversity can occur in small populations; however, in 
this case, it appears that there are adequate numbers of breeding 
adults to minimize loss of genetic diversity. Thus, we conclude that 
loss of genetic diversity is not a threat at the DPS level.
    Conservation of life-history diversity is important to the 
persistence of species confronted by habitat change and environmental 
perturbations (Beechie et al. 2006, entire). Therefore, the 
reintroductions of fluvial Arctic grayling into the upper Ruby River 
that have occurred provide redundancy of the fluvial ecotype. The 
number of breeding individuals in the Ruby River population has 
increased over the last 3 years (Leary 2014, unpublished data). Thus, 
there is now a viable replicate of the fluvial ecotype.
    Populations of Arctic grayling in the Upper Missouri River DPS are 
for the most part widely separated from one another, occupying 7 of 10 
historically occupied watersheds (see Table 3, above). Thus, risk of 
extirpation by a rare, high-magnitude environmental disturbance (i.e., 
catastrophe) is relatively low. In addition, multiple spawning 
locations exist for 11 of the 20 populations in the Upper Missouri 
River DPS. The 11 populations with access to multiple spawning 
tributaries include all the largest populations in terms of abundance, 
except Mussigbrod Lake (see Table 3). Abundance and number of breeding 
individuals is adequate in most populations to sustain moderate to high 
levels of genetic diversity currently observed. Based on this 
information, we conclude that stochastic processes are not a threat to 
the Upper Missouri River DPS of Arctic grayling and are not expected to 
be in the future.
Summary of Factor E
    Overall, we conclude that the Upper Missouri River DPS of Arctic 
grayling has faced historical threats from drought, loss of genetic 
diversity, and small population size. However, the DPS currently exists 
as multiple, isolated populations across a representative portion of 
its historical range. While reproductive isolation can lead to 
detrimental genetic effects, the current size of most Arctic grayling 
populations, trends in effective population size, and number of 
breeders suggest these effects will be minimal. Redundancies within and 
among populations are present: Multiple spawning tributaries, 
geographic separation, life-history replication. Given this 
information, we conclude the redundant nature of multiple resilient 
populations across a representative portion of the species' historical 
range minimizes the impacts of drought, low abundance, reduced genetic 
diversity, and lack of a fluvial ecotype replicate. Thus, these are not 
current threats, and are not expected to be threats in the future.

Cumulative Effects From Factors A Through E

    We limit our discussion of cumulative effects from Factors A 
through E to interactions involving climate change. Our rationale for 
this is that climate change has the highest level of uncertainty among 
other factors considered, and likely has the most potential to affect 
Arctic grayling populations when interacting with other factors.
Climate Change and Nonnative Species Interactions
    Changes in water temperature due to climate change may influence 
the distribution of nonnative trout species (Rahel and Olden 2008, p. 
524) and the outcome of competitive interactions between those species 
and Arctic grayling. Brown trout are generally considered to be more 
tolerant of warm water than many salmonid species common in western 
North America (Coutant 1999, pp. 52-53; Selong et al. 2001, p. 1032), 
and higher water temperatures may favor brown trout where they compete 
against salmonids with lower thermal tolerances (Rahel and Olden 2008, 
p. 524). Recently, observed increases in the abundance and distribution 
of brown trout in the upper reaches of the Big Hole River (MFWP 2013, 
unpublished data) may be consistent with the hypothesis that stream 
warming is facilitating encroachment. However, the effect of increased 
abundance and distribution of brown trout on Arctic grayling in the Big 
Hole River is unknown.
    Currently, brown trout are at relatively low densities (<20 fish/
mile) in the upper Big Hole River, where Arctic grayling densities are 
highest (MFWP 2013e, unpublished data). At densities of 100 brown trout 
per mile (a plausible future scenario), Arctic grayling experts 
predicted a 5 percent reduction in Arctic grayling recruitment in the 
Big Hole River, due to competition and predation (SSA 2014, p. 2). 
Given that natural mortality of salmonid fry is typically high (>90 
percent) (Kruse 1959, pp. 329, 333; Bradford 1995, p. 1330), the 
predicted reductions in Arctic grayling recruitment by current and 
future densities of brown trout in the Big Hole River will likely not 
impact Arctic grayling at the population level. Thus, the potential 
cumulative effect of climate change and nonnative species interactions 
is not a current or future threat for the Upper Missouri River DPS of 
Arctic grayling.
Climate Change and Dewatering
    Synergistic interactions are possible between effects of climate 
change and effects of other potential stressors such as dewatering. 
Increases in temperature and changes in precipitation are likely to 
affect the availability of water in the West. However, it is difficult 
to project how climate change will affect water availability because 
increased air and water temperatures may be accompanied and tempered by 
more frequent precipitation events. Uncertainty about how different 
temperature and precipitation scenarios could affect water availability 
make projecting possible synergistic effects of climate change on the 
Arctic grayling too speculative at this time.
Summary
    Recent genetic analyses have concluded that many of the introduced 
populations of Arctic grayling in the upper Missouri River basin 
contain moderate to high levels of genetic diversity and that these 
populations were created from local sources within the basin. These 
introduced populations currently occur within the confines of the upper 
Missouri River basin and occupy high quality habitats on Federal land, 
the same places the Service would look to for long-term conservation of 
the species, if needed. As such, these populations and their future 
adaptive potential have conservation value and are included in the 
Upper Missouri River DPS of Arctic grayling.
    Currently, we recognize 20 populations of Arctic grayling in the 
Upper Missouri River DPS, 18 of which occur on Federal land. Adequate 
regulatory mechanisms exist to ensure the conservation of habitat on 
Federal land for these populations. Historical habitat degradation on 
private land has affected the Big Hole River population; however, 
habitat conditions have been improving since the implementation of the 
Big Hole CCAA in 2006. Conservation actions associated with the Big 
Hole CCAA and SHCP have reduced water temperatures in tributaries, 
increased instream flows in

[[Page 49420]]

tributaries and the mainstem Big Hole River, connected almost all core 
habitat for Arctic grayling, and improved riparian health. Arctic 
grayling have responded favorably to these improvements because 
abundance and distribution have increased throughout the upper Big Hole 
River, and number of breeding adults has increased by a factor of at 
least 5 since 2006. The Service is encouraged by the successful track 
record of conservation actions implemented under the Big Hole CCAA and 
SHCP over the past 7 years.
    Riparian restoration efforts in the Big Hole River and Centennial 
Valley are ongoing and will continue to be key in mitigating the 
anticipated effects of drought and climate change. Increased shading of 
tributaries and decreased width-to-depth ratios in stream channels can 
effectively minimize effects from increasing air temperatures and 
drought. In addition, these changes to habitat can alter predation and 
competition potential where both nonnative species and Arctic grayling 
coexist, as they have for over 100 years in some populations.
    We acknowledge the uncertainty regarding the current status of the 
Ennis Reservoir/Madison River population and probable declining trend 
in abundance. The factors influencing the current demographics of this 
population are unclear. However, we are encouraged by the recent FERC 
relicensing agreement precluding reservoir drawdowns that likely 
affected this population and its habitat in the past.
    In conclusion, we find viable populations of both ecotypes present 
in the DPS, the majority of which occur on Federal land and are 
protected by Federal land management measures. Numbers of breeding 
adults are currently increasing in both strictly fluvial populations 
and in the Centennial Valley. High-quality habitat is present for most 
populations or is improving where it is not optimal (e.g., Big Hole 
River). Health of riparian areas is trending upward and will be key to 
minimizing effects of climate change and drought. All Arctic grayling 
populations are genetically diverse, are of Montana-origin, and occur 
in 7 of 10 historically occupied watersheds.
    In 2010, we identified multiple threats as acting on the Upper 
Missouri River DPS of Arctic grayling. At that time, we determined that 
habitat-related threats included habitat fragmentation, dewatering, 
thermal stress, entrainment, riparian habitat loss, and effects from 
climate change. Since 2010, we have 4 additional years of monitoring 
data and have gained new insight. It is now apparent that these threats 
are being effectively mitigated on private land (Big Hole River) by 
conservation actions under the Big Hole CCAA and do not appear to be 
present or acting at a level to warrant concern on most of the 
adfluvial populations. Almost all (98 percent) of Arctic grayling core 
habitat in the Big Hole River is now connected. Recent riparian 
restoration activities have appreciably reduced water temperatures and 
improved riparian habitat in tributaries to the Big Hole River and are 
expected to buffer the effects of climate change. Entrainment of Arctic 
grayling into irrigation canals in the Big Hole system is low, with no 
documented entrainment occurring since 2010. Habitats on Federal land 
are largely intact and these populations are not subject to many of the 
stressors historically identified for other populations because no 
irrigation diversions are present, habitats are primarily high-
elevation lakes that have cool water temperatures, and riparian areas 
are largely intact.
    In 2010, another threat identified as acting on the Upper Missouri 
River DPS of Arctic grayling was the presence of nonnative trout. We 
considered nonnative trout a threat at that time because we were aware 
of several instances where Arctic grayling declines had occurred 
following nonnative trout introductions. Currently, we have a better 
understanding of the interactions between nonnative trout and Arctic 
grayling. Our review of these interactions and case histories suggests 
that habitat degradation, concurrent with nonnative trout 
introductions, likely contributed to historical declines in Arctic 
grayling in those instances. Further, it appears the effect of 
nonnative trout on Arctic grayling are likely habitat-mediated; 
nonnative trout affect Arctic grayling disproportionately when habitat 
conditions are degraded, but both Arctic grayling and nonnatives can 
coexist at viable levels when habitat conditions are improved. The 
primary evidence supporting this assertion is the increasing abundance 
and distribution of both Arctic grayling and nonnatives in the Big Hole 
River (brown trout) and Centennial Valley (Yellowstone cutthroat trout 
before suppression began). Another line of evidence to support this 
assertion is observed spatial segregation between nonnatives and Arctic 
grayling in the core Arctic grayling areas in the Big Hole River, 
especially spawning and rearing areas (SSA 2014). In addition, Arctic 
grayling in adfluvial habitats have maintained stable or increasing 
population levels in the presence of brook, rainbow, and Yellowstone 
cutthroat trout for over 100 years in many instances in the upper 
Missouri River basin, where habitat degradation has not occurred or 
been extensive.
    In 2010, we stated that existing regulatory mechanisms were 
inadequate to protect the Upper Missouri River DPS of Arctic grayling. 
The primary reason for this assertion was that Arctic grayling 
populations were reported as declining; thus existing regulatory 
mechanisms were believed to be inadequate because they had failed to 
halt or reverse this decline. Currently, we have updated information 
indicating that 19 of 20 populations of Arctic grayling are either 
stable or increasing. Existing regulatory mechanisms have precluded 
riparian habitat destruction on Federal lands or mandated restoration 
of impaired areas and are expected to provide similar protections in 
the future. Given the updated information, we now believe these 
regulatory mechanisms are adequate.
    In 2010, we identified reduced genetic diversity, low abundance, 
random events, drought, and lack of a fluvial replicate as threats to 
the Upper Missouri River DPS of Arctic grayling. Updated genetic 
information that was not available in 2010 indicates moderate to high 
levels of genetic diversity within most Arctic grayling populations in 
the DPS. Further, abundance estimates derived from this updated genetic 
information indicate higher Arctic grayling abundances than previously 
thought. Adequate redundancy exists within the DPS to minimize the 
effects of random events and drought; lake habitats occupied by most 
Arctic grayling populations are drought-resistant. Lastly, a viable 
fluvial replicate now exists (Ruby River), with 5 years of natural 
reproduction documented and an increasing number of breeding adults.

Finding

    As required by the Act, we considered the five factors in assessing 
whether the Upper Missouri River DPS of Arctic grayling is endangered 
or threatened throughout all of its range. We examined the best 
scientific and commercial information available regarding the present 
and future threats faced by the Upper Missouri River DPS of Arctic 
grayling. We reviewed the petition, information available in our files 
and other available published and unpublished information, including 
information submitted by the public, and we consulted with recognized 
Arctic grayling experts and other Federal and State agencies. Habitat-
related threats previously identified,

[[Page 49421]]

including habitat fragmentation, dewatering, thermal stress, 
entrainment, riparian habitat loss, and effects from climate change, 
have been sufficiently ameliorated and the information indicates that 
19 of 20 populations of Arctic grayling are either stable or 
increasing. On the basis of the best scientific and commercial 
information available and the analysis provided above, we find that the 
magnitude and imminence of threats do not indicate that the Upper 
Missouri River DPS of Arctic grayling is in danger of extinction 
(endangered), or likely to become endangered within the foreseeable 
future (threatened), throughout its range. Therefore, we find that 
listing the Upper Missouri River DPS throughout its range as a 
threatened or an endangered species is not warranted at this time.

Significant Portion of the Range

    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 [DPS] of any species of vertebrate fish or wildlife which 
interbreeds when mature.'' On July 1, 2014, we published a final policy 
interpreting the phrase ``Significant Portion of its Range'' (SPR) (79 
FR 37578). 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 FWS 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 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. We 
emphasize that 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.''
    We evaluated the current range of the Upper Missouri River DPS of 
Arctic grayling to determine if there is any apparent geographic 
concentration of potential threats. We examined potential threats from 
curtailment of range, dams, habitat fragmentation, dewatering and 
thermal stress, entrainment, riparian habitat loss, sediment, 
exploitation, disease and competition/predation, drought, climate 
change, stochastic events, reduced genetic diversity, low abundance, 
and lack of a fluvial ecotype replicate. The type and magnitude of 
stressors acting on the Arctic grayling populations in the DPS are 
varied.
    Currently, nineteen of the twenty Arctic grayling populations in 
the DPS are stable or increasing in abundance. Given this trend, we 
conclude that there is no concentration of threats acting on these 
nineteen populations because these populations are able to maintain 
viability, despite some stressors acting at the individual level on 
some of these populations. However, we acknowledge the probable 
declining population trend in the Ennis Reservoir/Madison River 
population. It is unclear what factor or

[[Page 49422]]

combination of factors is contributing to this decline. Nonnative trout 
abundance is highest in the Madison River, relative to all other 
systems occupied by nonnative trout and Arctic grayling, and this 
factor may be contributing to the decline of Arctic grayling in Ennis 
Reservoir/Madison River.
    Given the probable decline of Arctic grayling in Ennis Reservoir/
Madison River, we analyzed the potential significance of this 
population to the overall Upper Missouri River DPS of Arctic grayling. 
To do this analysis, we evaluated whether the Ennis Reservoir/Madison 
River population's contribution to the viability of the DPS is so 
important that, without the members in this portion, the DPS would be 
in danger of extinction, or likely to become so in the foreseeable 
future, throughout all of its range. The Ennis Reservoir/Madison River 
population occupies a small portion of the range within the DPS and 
represents only 1 of 20 populations in the overall DPS. We conclude 
that the DPS would still be viable if the Ennis Reservoir/Madison River 
population were extirpated because adequate redundancy (3 other fluvial 
or partially fluvial and 16 other adfluvial populations) of Arctic 
grayling populations would still exist. In addition, representation of 
resilient populations would remain in the Madison drainage (Grebe Lake 
population) and rangewide in 7 of 10 historically occupied watersheds 
in the Upper Missouri River basin. Further, resiliency of the DPS would 
not be compromised by the loss of the Ennis Reservoir/Madison River 
population because all remaining Arctic grayling populations are 
widespread and viable. Therefore, in the hypothetical absence of the 
Ennis Reservoir/Madison River population, the remainder of the Upper 
Missouri River DPS of Arctic grayling would not meet the definition of 
threatened or endangered under the Act. For the reasons stated above, 
the Ennis Reservoir/Madison River population does not meet the 
definition of ``significant'' for the purposes of this SPR analysis.
    In conclusion, we find no concentration of stressors acting on 
nineteen of twenty Arctic grayling populations in the DPS. The Ennis 
Reservoir/Madison River population does appear to have a stressor or 
combination of stressors acting at the population level. However, 
further analysis indicates that the Ennis Reservoir/Madison River does 
not meet the definition of ``significant'' in our SPR policy because 
adequate redundancy, representation, and resiliency would still exist 
within the DPS if the Ennis Reservoir/Madison River population were 
extirpated. Thus, the remainder of the Upper Missouri River DPS of 
Arctic grayling would not meet the definition of threatened or 
endangered. Therefore, we find that there is not a significant portion 
of the range of the Upper Missouri River DPS of Arctic grayling that 
warrants listing.
    Our review of the best available scientific and commercial 
information indicates that the Upper Missouri River DPS of Arctic 
grayling is not in danger of extinction (endangered), nor likely to 
become endangered within the foreseeable future (threatened), 
throughout all or a significant portion of its range. Therefore, we 
find that listing the Upper Missouri River DPS of Arctic grayling as an 
endangered or threatened species under the Act is not warranted at this 
time.
    We request that you submit any new information concerning the 
status of, or threats to, the Upper Missouri River DPS of Arctic 
grayling to our Montana Ecological Services Office (see ADDRESSES) 
whenever it becomes available. New information will help us monitor the 
Upper Missouri River DPS of Arctic grayling and encourage its 
conservation. If an emergency situation develops for the Upper Missouri 
River DPS of Arctic grayling, we will act to provide immediate 
protection.

References Cited

    A complete list of references cited is available on the Internet at 
https://www.regulations.gov and upon request from the Montana Ecological 
Services Office (see ADDRESSES).

Authors

    The primary authors of this document are the staff members of the 
Montana Ecological Services 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: August 6, 2014.
David Cottingham,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2014-19353 Filed 8-19-14; 4:15 pm]
BILLING CODE 4310-55-P