[Federal Register Volume 75, Number 173 (Wednesday, September 8, 2010)]
[Proposed Rules]
[Pages 54707-54753]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-22038]



[[Page 54707]]

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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 
to List the Upper Missouri River Distinct Population Segment of Arctic 
Grayling as Endangered or Threatened; Proposed Rule

Federal Register / Vol. 75, No. 173 / Wednesday, September 8, 2010 / 
Proposed Rules

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2009-0065]
[MO 92210-0-0008-B2]


Endangered and Threatened Wildlife and Plants; Revised 12-Month 
Finding to List the Upper Missouri River Distinct Population Segment of 
Arctic Grayling as Endangered or Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of revised 12-month finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service/USFWS), 
announce a revised 12-month finding on a petition to list the upper 
Missouri River Distinct Population Segment (Missouri River DPS) of 
Arctic grayling (Thymallus arcticus) as endangered or threatened under 
the Endangered Species Act of 1973, as amended. After review of all 
available scientific and commercial information, we find that listing 
the upper Missouri River DPS of Arctic grayling as endangered or 
threatened is warranted. However, listing the upper Missouri River DPS 
of Arctic grayling is currently precluded by higher priority actions to 
amend the Lists of Endangered and Threatened Wildlife and Plants. Upon 
publication of this 12-month finding, we will add the upper Missouri 
River DPS of Arctic grayling to our candidate species list. We will 
develop a proposed rule to list this DPS as our priorities allow. We 
will make any determination on critical habitat during development of 
the proposed listing rule. In the interim, we will address the status 
of this DPS through our annual Candidate Notice of Review (CNOR).

DATES: The finding announced in this document was made on September 8, 
2010.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R6-ES-2009-0065. 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 Field Office, 585 Shepard Way, 
Helena, MT 59601. Please submit any new information, materials, 
comments, or questions concerning this finding to the above street 
address (Attention: Arctic grayling).

FOR FURTHER INFORMATION CONTACT: Mark Wilson, Field Supervisor, Montana 
Field Office (see ADDRESSES); by telephone at 406-449-5225; or by 
facsimile at 406-449-5339. Persons who use a telecommunications device 
for the deaf (TDD) may call the Federal Information Relay Service 
(FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (ESA) (16 U.S.C. 1531 et seq.), requires that, for any petition 
containing substantial scientific or commercial information indicating 
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 
determine that the petitioned action is: (a) Not warranted, (b) 
warranted, or (c) warranted, but immediate proposal of a regulation 
implementing the petitioned action is precluded by other pending 
proposals to determine whether species are endangered or threatened, 
and expeditious progress is being made to add or remove qualified 
species from the Federal Lists of Endangered and Threatened Wildlife 
and Plants. Section 4(b)(3)(C) of the ESA requires that we treat a 
petition for which the requested action is found to be warranted but 
precluded as though resubmitted on the date of such finding, that is, 
requiring a subsequent finding to be made within 12 months. We must 
publish these 12-month findings in the Federal Register.

Previous Federal Actions

    We have published a number of documents on Arctic grayling and have 
been involved in litigation over previous findings. We describe our 
actions relevant to this notice below.
    We initiated a status review for the Montana Arctic grayling 
(Thymallus arcticus montanus) in a Federal Register notice on December 
30, 1982 (47 FR 58454). In that notice, 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 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 a notice 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. On May 4, 2004, we elevated the listing priority number of the 
fluvial Arctic grayling to 3 (69 FR 24881).
    On May 31, 2003, the Center for Biological Diversity and Western 
Watersheds Project (Plaintiffs) filed a complaint in U.S. District 
Court in Washington, D.C., challenging our ``warranted but precluded'' 
determination for Montana fluvial Arctic grayling. 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 final 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 ESA. Therefore, 
we found that the upper Missouri River population of fluvial Arctic 
grayling was not a listable entity under the ESA, and as a result, 
listing was not warranted. With that notice, we withdrew the fluvial 
Arctic grayling from the candidate list.

[[Page 54709]]

    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 notice 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 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. The notice further 
specified that the status review may consider various DPS designations 
that include different life histories of Arctic grayling in the upper 
Missouri River system. Specifically, we may consider DPS configurations 
that include: Fluvial, adfluvial (lake populations), or all life 
histories of Arctic grayling in the upper Missouri River system.
    This notice constitutes the revised 12-month finding (``2010 
finding'') on whether to list the upper Missouri River DPS of Arctic 
grayling (Thymallus arcticus) as endangered or threatened.
Taxonomy and Species Description
    The Arctic grayling (Thymallus arcticus) belongs to the family 
Salmonidae (salmon, trout, charr, whitefishes), subfamily Thymallinae 
(graylings), and it is represented by a single genus, Thymallus. Scott 
and Crossman (1998, p. 301) recognize four species within the genus: T. 
articus (Arctic grayling), T. thymallus (European grayling), T. 
brevirostris (Mongolian grayling), and T. nigrescens (Lake Kosgol, 
Mongolia). Recent research focusing on Eurasian Thymallus (Koskinen et 
al. 2002, entire; Froufe et al. 2003, entire; Froufe et al. 2005, 
entire; Weiss et al. 2006, entire) indicates that the systematic 
diversity of the genus is greater than previously thought, or at least 
needs better description (Knizhin et al. 2008, pp. 725-726, 729; 
Knizhin and Weiss 2009, pp. 1, 7-8; Weiss et al. 2007, p. 384).
    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). The sides are marked with a 
varying number of V-shaped or diamond-shaped spots (Scott and Crossman 
1998, p. 301). During the spawning period, the colors darken and the 
males become more brilliantly colored than the females. 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).
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; see Figure 1 below). 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).
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[GRAPHIC] [TIFF OMITTED] TP08SE10.000

    FIGURE 1. Approximate world-wide distribution of Arctic grayling 
(Thymallus arcticus) at the end of the most recent glacial cycle. The 
Missouri River distribution is based on Kaya (1992, pp. 47-51). The 
distribution of the extinct Michigan population is based on Vincent 
(1962, p. 12) and the University of Michigan (2010). The North American 
distribution in Canada and Alaska is based on Behnke (2002, p. 330) and 
Scott and Crossman (1998, pp. 301-302). The Eurasian distribution is 
based on Knizhin (2009, p. 32) and Knizhin (2010, pers. comm.).
    Arctic grayling remains widely distributed across its native range, 
but within North America, the species has experienced range decline or 
contraction at the southern limits of its distribution. In British 
Columbia, Canada, populations in the Williston River watershed are 
designated as a provincial ``red list'' species, meaning the population 
is a candidate for further evaluation to determine if it should be 
granted endangered (facing imminent extirpation or extinction) or 
threatened status (likely to become endangered) (British Columbia 
Conservation Data Centre 2010). In Alberta, Canada, Arctic grayling are 
native to the Athabasca, Peace, and Hay River drainages. In Alberta, 
the species has undergone a range contraction of about 40 percent, and 
half of the province's subpopulations have declined in abundance by 
more than 90 percent (Alberta Sustainable Resource Development (ASRD) 
2005, p. iv).

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 (extant in Montana, see Figure 2), and another in 
Michigan that was extirpated in the late 1930s (Hubbs and Lagler 1949, 
p. 44). Michigan grayling formerly occurred in the Otter River of the 
Lake Superior drainage in northern Michigan and in streams of the lower 
peninsula of Michigan in both the Lake Michigan and Lake Huron 
drainages including the Au Sable, Cheboygan, Jordan, Pigeon, and Rifle 
Rivers (Vincent 1962, p. 12).
    Introduced Lake Dwelling Arctic Grayling in the Upper Missouri 
River

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System and western U.S. populations of Arctic grayling have been 
established in lakes outside their native range in Arizona, Colorado, 
Idaho, Montana, New Mexico, Utah, Washington, and Wyoming (Vincent 
1962, p. 15; Montana Fisheries Information System (MFISH) 2009; 
NatureServe 2010). Stocking of hatchery grayling in Montana has been 
particularly extensive, and there are thought to be up to 78 introduced 
lacustrine (lake-dwelling) populations resulting from these 
introductions (see Table 1 below). Over three-quarters of these 
introductions (79.5 percent) were established outside the native 
geographic range of upper Missouri River grayling, while only 16 (20.5 
percent) were established within the watershed boundary of the upper 
Missouri River system.
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    FIGURE 2. Historical (dark grey lines) and current distribution 
(stars and circled portion of Big Hole River) of native Arctic grayling 
in the upper Missouri River basin. White bars denote mainstem river 
dams that are total barriers to upstream passage by fish.

   TABLE 1. Introduced Lake-dwelling Populations of Arctic Grayling in
Montana. The primary data source for these designations is MFISH (2009).
------------------------------------------------------------------------
                                                   Number of Introduced
                  River Basin                    (Exotic) Populations\a\
------------------------------------------------------------------------
               Outside Native Geographic Range In Montana
------------------------------------------------------------------------
Columbia River                                                        23
------------------------------------------------------------------------
Middle Missouri River                                                  2
------------------------------------------------------------------------
Saskatchewan River                                                     1
------------------------------------------------------------------------
Yellowstone River                                                  36\b\
------------------------------------------------------------------------
     Within Watershed Boundary Of Native Geographic Range In Montana
------------------------------------------------------------------------
Upper Missouri River                                                  16
------------------------------------------------------------------------
Total Exotic Populations                                              78
------------------------------------------------------------------------
\a\List of populations does not include lake populations derived from
  attempts to re-establish fluvial populations in Montana, native
  adfluvial populations, or genetic reserves of Big Hole River grayling.
\b\Many of these populations may not reproduce naturally and are only
  sustained through repeated stocking (Montana Fish, Wildlife and Parks
  2009, entire).

    For the purposes of this finding, we are analyzing a petitioned 
entity that includes, at its maximum extent, populations of Arctic 
grayling considered native to the upper Missouri River. Introduced 
populations present in Montana (e.g., Table 1) or elsewhere are not 
considered as part of the listable entity because we do not consider 
them to be native populations. Neither the Act nor our implementing 
regulations expressly address whether introduced populations should be 
considered part of an entity being evaluated for listing, and no 
Service policy addresses the issue. Consequently, in our evaluation of 
whether or not to include introduced populations in the potential 
listable entity we considered the following: (1) Our interpretation of 
the intent of the Act with respect to the disposition of native 
populations, (2) a policy used by the National Marine Fishery Service 
(NMFS) to evaluate whether hatchery-origin populations warrant 
inclusion in the listable entity, and (3) a set of guidelines from 
another organization (International Union for Conservation of Nature 
and Natural Resources (IUCN)) with specific criteria for evaluating the 
conservation contribution of introduced populations.

Intent of the Endangered Species Act

    The primary purpose of the Act is to provide a means whereby the 
ecosystems upon which endangered species and threatened species depend 
may be conserved. The Service has interpreted the Act to provide a 
statutory directive to conserve species in their native ecosystems (49 
FR 33890, August 27, 1984) and to conserve genetic resources and 
biodiversity over a representative portion of a taxon's historical 
occurrence (61 FR 4723, February 7, 1996). This priority on natural 
populations is evident in the Service's DPS policy within the third 
significance criteria. In that, a discrete population segment may be 
significant if it represents the only surviving natural occurrence of 
the taxon that may be more abundant elsewhere as an introduced 
population outside of its historical range.

National Marine Fishery Service Hatchery Policy

    In 2005, the NMFS published a 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). A central tenet of this policy is the primacy of the 
conservation of naturally spawning salmon populations and the 
ecosystems on which they depend, consistent with the intent of the Act 
(NMFS 2005, pp. 37211, 37214). The policy recognizes that properly 
managed hatchery programs may provide some conservation benefit to the 
evolutionary significant unit (ESU, which is analogous to a DPS but 
applied to Pacific salmon) (NMFS 2005, p. 37211), and that hatchery 
stocks that contribute to survival and recovery of an ESU are 
considered during a listing decision (NMFS 2005, p. 37209). The policy 
states that since hatchery stocks are established and maintained with 
the intent of furthering the viability of wild populations in the ESU, 
that those hatchery populations have an explicit conservation value. 
Genetic divergence is the preferred metric to determine if hatchery 
fish should be included in the ESU, but NMFS recognizes that these data 
may be lacking in most cases (NMFS 2005, p. 37209). Thus, proxies for 
genetic divergence can be used, such as the length of time a stock has 
been isolated from its source population, the degree to which natural 
broodstock has been regularly incorporated into the hatchery 
population, the history of non-ESU fish or eggs in the hatchery 
population, and the attention given to genetic considerations in 
selecting and mating broodstocks (NMFS 2005, p. 37209).
    The NMFS policy applies to artificially propagated (hatchery) 
populations. In this finding, however, the Service is deciding whether 
self-sustaining populations introduced outside its natural range should 
be included in the listable entity. Thus, the NMFS policy is not 
directly applicable. Nonetheless, if the NFMS policy's criteria are 
applied to the introduced lake-dwelling populations of Arctic grayling 
in Montana and elsewhere, these populations do not appear to warrant 
inclusion in the entity being evaluated for listing. First, there does 
not appear to be any formally recognized conservation value for the

[[Page 54713]]

introduced populations of Arctic grayling, and they are not being used 
in restoration programs. Recent genetic analysis indicates that many of 
the introduced Arctic grayling populations in Montana are derived, in 
part, from stocks in the Red Rock Lakes system (Peterson and Ardren 
2009, p. 1767). Nonetheless, there have been concerns that introduced, 
lake-dwelling populations could pose genetic risks to the native 
fluvial population (Arctic Grayling Workgroup (AGW) 1995, p. 15), and 
in practice, these introduced populations have not been used for any 
conservation purpose. In fact, efforts are currently underway to 
establish a genetically pure brood reserve population of Red Rock Lakes 
grayling to be used for conservation purposes (Jordan 2010, pers. 
comm.), analogous to the brood reserves maintained for Arctic grayling 
from the Big Hole River (Rens and Magee 2007, pp. 22-24).
    Second, introduced populations in lakes have apparently been 
isolated from their original source stock for decades without any 
supplementation from the wild. These populations were apparently 
established without any formal genetic consideration to selecting and 
mating broodstock, the source populations were not well documented 
(Peterson and Ardren 2009, p. 1767), and the primary intent of 
culturing and introducing these grayling appears to have been to 
provide recreational fishing opportunities in high mountain lakes.

Guidelines Used in Other Evaluation Systems

    The IUCN uses its Red List system to evaluate the conservation 
status and relative risk of extinction for species, and to catalogue 
and highlight plant and animal species that are facing a higher risk of 
global extinction (http://www.iucnredlist.org). IUCN does not use the 
term ``listable entity'' as the Service does; however, IUCN does 
clarify that their conservation ranking criteria apply to any taxonomic 
group at the species level or below (IUCN 2001, p.4). Further, the IUCN 
guidelines for species status and scope of the categorization process 
focus on wild populations inside their natural range (IUCN 2001, p. 4; 
2003, p. 10) or so-called ``benign'' or ``conservation introductions,'' 
which are defined as attempts to establish a species, for the purpose 
of conservation, outside its recorded distribution, when suitable 
habitat is lacking within the historical range (IUCN 1998, p. 6; 2003, 
pp. 6, 10). Guidelines for evaluating conservation status under the 
IUCN exclude introduced populations located outside the recorded 
distribution of the species if such populations were established for 
commercial or sporting purposes (IUCN 1998, p. 5; 2003, p. 24). In 
effect, the IUCN delineates between introduced and native populations 
in that non-benign introductions do not qualify for evaluation under 
the IUCN Red List system. Naturalized populations of Arctic grayling in 
lakes thus do not meet the IUCN criterion for a wild population that 
should be considered when evaluating the species status for two 
reasons. First, there remains `suitable habitat' for Arctic grayling in 
its native range, as evidenced by extant native populations in the Big 
Hole River, Madison River, Miner Lake, Mussigbrod Lake, and Red Rock 
Lakes. Second, the naturalized populations derived from widespread 
stocking were apparently aimed at establishing recreational fisheries.
    Our interpretation is that the ESA is intended to preserve native 
populations in their ecosystems. While hatchery or introduced 
populations of fishes may have some conservation value, this does not 
appear to be the case with introduced populations of Arctic grayling in 
the conterminous United States. These populations were apparently 
established to support recreational fisheries, and without any formal 
genetic consideration to selecting and mating broodstock, and are not 
part of any conservation program to benefit the native populations. 
Consequently, we do not consider the introduced populations of Arctic 
grayling in Montana and elsewhere in the conterminous United States, 
including those in lakes and in an irrigation canal (Sun River Slope 
Canal), to be part of the listable entity.
Native Distribution in the Upper Missouri River System
    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 2). 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). ``Old-timer'' accounts report that the 
species may have been present in the Ruby River, at least seasonally 
(Magee 2005, pers. comm.), and were observed as recently as the early 
1970s (Holton, undated).
    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 headwaters of the Beaverhead River (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 
grayling there were the only native adfluvial population in the basin. 
However, it appears that Arctic grayling also were native to Elk Lake 
(in the Red Rocks drainage; Kaya 1990, p. 44) and a few small lakes in 
the upper Big Hole River drainage (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 Smith, Sun, Jefferson, Beaverhead, Gallatin, 
and mainstem Missouri Rivers are considered extirpated, and the only 
remaining indigenous fluvial population is found in the Big Hole River 
and some if its tributaries (Kaya 1992, pp. 51-53). The fluvial form 
currently occupies only 4 to 5 percent of its historic range in the 
Missouri River system (Kaya 1992, p. 51). Other remaining 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 Madison River upstream from Ennis Reservoir; and the Red Rock Lakes 
in the headwaters of the Beaverhead River system (Everett 1986, p. 7; 
Kaya 1992, p. 53; Peterson and Ardren 2009, pp. 1762, 1768; Figure 1 
above, and Table 2 below).

[[Page 54714]]



TABLE 2. Extant Native Arctic Grayling Populations in the Upper Missouri
                              River Basin.
------------------------------------------------------------------------
                       Big Hole River Drainage\a\
-------------------------------------------------------------------------
1. Big Hole River
------------------------------------------------------------------------
2. Miner Lake
------------------------------------------------------------------------
3. Mussigbrod Lake
------------------------------------------------------------------------
                         Madison River Drainage
------------------------------------------------------------------------
4. Madison River-Ennis Reservoir
------------------------------------------------------------------------
                        Beaverhead River Drainage
------------------------------------------------------------------------
5. Red Rock Lakes
------------------------------------------------------------------------
\a\Arctic grayling also occur in Pintler Lake in the Big Hole River
  drainage, but this population has not been evaluated with genetic
  markers to determine whether it constitutes a native remnant
  population.

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). A Eurasian origin is suggested by the substantial taxonomic 
diversity found in the genus in that region. 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).
    The North American distribution of Arctic grayling was strongly 
influenced by patterns of glaciation. Genetic studies of 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 (Stamford and Taylor 
2004, pp. 1533, 1540). The Nahanni lineage is the most genetically 
distinct group (Stamford and Taylor 2004, pp. 1541-1543). Arctic 
grayling from the upper Missouri River basin were tentatively placed in 
the North Beringia lineage because a small sample (three individuals) 
of Montana 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 and biogeographic history indicate that Missouri River 
grayling have been physically and reproductively isolated from northern 
populations for millennia. The most recent ancestors of Missouri River 
Arctic grayling likely spent the last glacial cycle in an ice-free 
refuge south of the Laurentide and Cordilleran ice sheets. 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 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 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 much of their original ancestry to Red Rock Lakes 
(Peterson and Ardren 2009, p. 1767), and stocking of hatchery grayling 
did not appear to 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 grayling ecotypes 
(adfluvial, fluvial) do not appear to be as large as differences 
resulting from geography (i.e., drainage of origin).

[[Page 54715]]

Habitat
    Arctic grayling generally require clear, cold water. Selong et al. 
(2001, p. 1032) characterized Arctic grayling as belonging to a 
``coldwater'' group of salmonids, which also includes bull trout 
(Salvelinus confluentus) and Arctic char (Salvelinus alpinus). Hubert 
et al. (1985, p. 24) developed a habitat suitability index study for 
Arctic grayling and concluded that thermal habitat was optimal between 
7 to 17 [deg]C (45 to 63 [deg]F), but became unsuitable above 20[deg]C 
(68[deg]F). 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) 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, p. 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 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).
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). Arctic grayling in lakes 
typically migrate to either the inlet or outlet to spawn (Armstrong 
1986, p. 8; Northcote 1997, p. 148). In either situation, Arctic 
grayling typically exhibit natal homing, whereby individuals spawn in 
or near the location where they were born (Northcote 1997, pp. 157-
160).
    Fry from river populations typically seek feeding and rearing 
habitats in the vicinity where they were spawned (Armstrong 1986, pp. 
6-7; 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). 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
    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. 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 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

[[Page 54716]]

differentiated from a common ancestor 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 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.
    However, the ability of one ecotype of Arctic grayling to give rise 
to a functional population of the other ecotype within a few decades is 
much less certain, and may parallel the differences in plasticity that 
have evolved between river- and lake-type European grayling (Salonen 
2005, entire). 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). In contrast, a population of Arctic grayling in the 
Madison River that would have presumably expressed a fluvial ecotype 
under historical conditions has apparently adapted to an adfluvial 
life-history after construction of an impassible dam, which impounded 
Ennis Reservoir (Kaya 1992, p. 53; Jeanes 1996, pp. 54). 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). 
While in some cases Arctic grayling may be able to adapt or adjust 
rapidly to a new environment, the frequent failure of introductions of 
Arctic grayling suggest a cautionary approach to the loss of particular 
life-history forms is warranted. Healey and Prince (1995, entire) 
reviewed patterns of genotypic and phenotypic variation in Pacific 
salmon and warn that recovery of lost life-history forms may not follow 
directly from conservation of the genotype (p. 181), and reason that 
the critical conservation unit is the population within its habitat (p. 
181).
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). 
Similarly, Nelson (1954, pp. 333-334) observed that the majority of the 
Arctic grayling spawning in two tributaries in the Red Rock Lakes 
system, Montana, were age 3, and the oldest individuals aged from a 
larger sample were age 6. Mogen (1996, pp. 32-34) found that Arctic 
grayling spawning in Red Rock Creek were mostly ages 2 to 5, but he did 
encounter some individuals age 7.
    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) appear to 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). Growth rates of Arctic grayling from 
different management areas in Alberta are nearly as high as those 
observed in Montana grayling (ASRD 2005, p. 4).

Distinct Population Segment

    In its stipulated settlement with Plaintiffs, the Service agreed to 
consider the appropriateness of DPS designations for Arctic grayling 
populations in the upper Missouri River basin that included: (a) All 
life ecotypes or histories, (b) the fluvial ecotype, and (c) the 
adfluvial ecotype. The fluvial ecotype has been the primary focus of 
past Service action and litigation, but the Service also has alluded to 
the possibility of alternative DPS designations in previous candidate 
species assessments (USFWS 2005, p. 11). Since the 2007 finding (72 FR 
20305), additional research has been conducted and new information on 
the genetics of Arctic grayling is available. This finding contains a 
more comprehensive and robust distinct population segment analysis than 
the 2007 finding.

Distinct Population Segment Analysis for Native Arctic Graying in the 
Upper Missouri River

Discreteness

    The discreteness standard under the Service's and National Oceanic 
and Atmospheric Administration's (NOAA) joint Policy Regarding the 
Recognition of Distinct Vertebrate Population Segments Under the 
Endangered Species Act (61 FR 4722) requires an entity to be adequately 
defined and described in some way that distinguishes it from other 
representatives of its species. A segment is discrete if it is: (1) 
Markedly separated from other populations of the same taxon as 
consequence of physical, physiological, ecological, or behavioral 
factors (quantitative measures of genetic or morphological 
discontinuity may provide evidence of this separation); or (2) 
delimited by international

[[Page 54717]]

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 ESA.
    Arctic grayling native to the upper Missouri River are isolated 
from populations of the species inhabiting the Arctic Ocean, Hudson 
Bay, and north Pacific Ocean drainages in Asia and North America (see 
Figure 1). 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 we determine that a population meets the DPS discreteness 
element, we then consider whether it also meets the DPS significance 
element. The DPS policy states that, if a population segment is 
considered discrete under one or more of the discreteness criteria, 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 
(see U.S. Congress 1979, Senate Report 151, 96\th\ Congress, 1st 
Session). In making this determination, we consider available 
scientific evidence of the discrete population'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 does provide four possible reasons why a discrete 
population may be significant. As specified in the DPS policy, this 
consideration of significance may include, but is not limited to, the 
following: (1) Persistence of the discrete population segment in a 
unique or unusual ecological setting; (2) evidence that loss of the 
discrete segment would result in a significant gap in the range of the 
taxon; (3) evidence that the discrete population segment represents the 
only surviving natural occurrence of the taxon that may be more 
abundant elsewhere as an introduced population outside of its historic 
range; or (4) evidence that the discrete population segment differs 
markedly from other populations of the species in its genetic 
characteristics.

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 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). 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 3. 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
------------------------------------------------------------------------
Ocean watershed                   Gulf of Mexico-     Hudson Bay, Arctic
                                   Atlantic Ocean      Ocean, or north
                                                       Pacific
------------------------------------------------------------------------
Bailey's Ecoregion                Dry Domain:         Polar Domain:
                                   Temperate Steppe    Tundra &
                                                       Subarctic Humid
                                                       Temperate:
                                                       Marine,
                                                      Prairie, Warm
                                                       Continental
                                                      Mountains
------------------------------------------------------------------------
Air temperature (isotherm)        5 to 10 [deg]C      -15 to 5 [deg]C
                                  (41 to 50 [deg]F).  (5 to 41 [deg]F)
------------------------------------------------------------------------

[[Page 54718]]

 
Groundwater temperature           4 to 7[deg]C        Less than 4 [deg]C
 (isotherm)                       (39 to 45 [deg]F).  (less than 39
                                                       [deg]F)
------------------------------------------------------------------------
Native occurrence of large-       None, in most of    Bull trout, lake
 bodied fish predators on          the range\a\        trout, northern
 salmonids                                             pike, taimen
------------------------------------------------------------------------
\a\Lake trout are native to two small lakes in the upper Missouri River
  basin (Twin Lakes and Elk Lake), where their distributions presumably
  overlapped with the native range of Arctic grayling, so they would not
  have interacted with most Arctic grayling populations in the basin
  that were found in rivers.

    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 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; see 
Table 3 above). 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.
    An apex fish predator that preys successfully on salmonids has been 
largely absent from most of the upper Missouri River basin over 
evolutionary time scales (tens of thousands of years). This suggests 
that Arctic grayling in the upper Missouri River basin have faced a 
different selective pressure than Arctic grayling in many other areas 
of the species' range, at least with respect to predation by fishes. 
Predators can exert a strong selective pressure on populations. One 
noteworthy aspect of the aquatic biota experienced by Arctic grayling 
in the upper Missouri River is the apparent absence of a large-bodied 
fish that would be an effective predator on juvenile and adult 
salmonids. In contrast, one or more species of large predatory fishes 
like northern pike (Esox lucius), bull trout, taimen (Hucho taimen), 
and lake trout (Salvelinus namaycush) are broadly distributed across 
much of the range of Arctic grayling in Canada and Asia (Northern 
pike--Scott and Crossman 1998, pp. 302, 358; taimen--VanderZanden et 
al. 2007, pp. 2281-2282; Esteve et al. 2009, p. 185; bull trout--Behnke 
2002, pp. 296, 330; lake trout --Behnke 2002, pp. 296, 330). The only 
exceptions to this general pattern are where Arctic grayling formerly 
coexisted with lake trout native to Twin Lakes and Elk Lake (Beaverhead 
County) (Vincent 1963, pp. 188-189), but both of these Arctic grayling 
populations are thought to be extirpated (Oswald 2000, pp. 10, 16; 
Oswald 2006, pers. comm.). The burbot (Lota lota) is a freshwater fish 
belonging to the cod family and is native to the Missouri, Big Hole, 
Beaverhead, Ruby, and Madison Rivers in Montana (MFISH 2010); thus its 
distribution significantly overlapped the historical and current ranges 
of Arctic grayling in the upper Missouri River system. Burbot are 
voracious predators, but tend to be benthic (bottom-oriented) and 
apparently prefer the deeper portions of larger rivers and lakes. A few 
studies have investigated the diet of burbot where they overlap with 
native Arctic grayling in Montana, but did not detect any predation on 
Arctic grayling (Streu 1990, pp. 16-20; Katzman 1998, pp. 98-100). 
Burbot apparently do not consume salmonids in significant amounts, even 
when they are very abundant (Katzman 1998 and references therein, p. 
106). The response of Arctic grayling in the Missouri River basin to 
introduced,

[[Page 54719]]

nonnative trout suggests they were not generally pre-adapted to cope 
with the presence of a large-bodied salmonid predator. Missouri River 
Arctic grayling lack a co-evolutionary history with brown trout, and 
there are repeated observations that the two species tend not to 
coexist and that brown trout displace Arctic grayling (Kaya 1992, p. 
56; 2000, pp. 14-15). We caution that competition with and predation by 
brown trout has not been directly studied with Arctic grayling, but at 
least some circumstantial evidence indicates that Missouri River Arctic 
grayling may not coexist well with brown trout.
    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 distinctly different ecological setting 
relative to the rest of the species (see Table 3 above), and that they 
have been on a different evolutionary trajectory for at least 10,000 
years. Consequently, we believe that Arctic grayling in the upper 
Missouri River occupy a unique ecological setting. The role that this 
unique setting plays in influencing adaptations or determining unique 
traits is unclear, and therefore a determination of the significance of 
this ecological setting to the taxon is unknown.

Gap in the Range

    Arctic grayling in the upper Missouri River basin occur in an ocean 
drainage basin that is distinct from all other Arctic grayling 
populations worldwide. All other Arctic grayling occur in drainages of 
Hudson Bay, the Arctic Ocean, or the north Pacific Ocean; the Missouri 
River is part of the Gulf of Mexico-Atlantic Ocean drainage. The 
significance of occupancy of this drainage basin is that the upper 
Missouri River basin represents an important part of the species' range 
from a biogeographic perspective. The only other population of Arctic 
grayling to live in a non-Arctic environment was the Michigan-Great 
Lakes population that was extirpated in the 1930s.
    Arctic grayling in Montana (southern extent is approximately 
44[deg]36[min]23[sec] N latitude) represent the southern-most extant 
population of the species' distribution since the Pleistocene 
glaciation (Figure 1). The next-closest native Arctic grayling 
population outside the Missouri River basin is found in the Pembina 
River (approximately 52[deg]55[min]6.77[sec] N latitude) in central 
Alberta, Canada, west of Edmonton (Blackburn and Johnson 2004, pp. ii, 
17; ASRD 2005, p. 6). 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. Such a dramatic range constriction would 
constitute a significant geographic gap in the species' range, and 
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 
(see reviews by Scudder 1989, entire; Lesica and Allendorf 1995, 
entire; Fraser 2000, entire). 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 from the upper Missouri River's occurrence 
at the southernmost extreme of the range contributes to its 
significance that may increased adaptability and contribute to the 
resilience of the overall 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. That said, there are introduced Lake 
Dwelling Arctic Grayling within the native range in the Upper Missouri 
River System and Arctic grayling have been established in lakes outside 
their native range in Arizona, Colorado, Idaho, Montana, New Mexico, 
Utah, Washington, and Wyoming (Vincent 1962, p. 15; Montana Fisheries 
Information System (MFISH) 2009; NatureServe 2010).

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 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 electrophoretic 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 a unique isocitrate dehydrogenase allele (form 
of a gene) and a unique malate dehydrogenase allele, which strongly 
differentiated them from all the other samples (Everett 1986, p. 44). 
With the exception one introduced population 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 superoxide dismutase 
(Everett 1986, p. 60; Leary 2005, p. 1), and contained a unique variant 
of the malate dehydrogenase (Leary 2005, p. 1). Overall, each of the 
four native Missouri River populations examined (Big Hole, Miner, 
Mussigbrod, and Red Rock) 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) results in

[[Page 54720]]

information from 21 allozyme loci (genes) from the 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 suggest 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 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). Analysis of 
Arctic grayling using restriction enzymes and DNA sequencing indicated 
that the fish from the upper Missouri River drainage possessed, in 
terms of North American fish, an ancestral form of the molecule 
(different forms of mtDNA molecules are referred to as haplotypes) 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 (2 of 24 individuals in the population), and all 
sampled individuals from the Saskatchewan River drainage Saskatchewan, 
Canada (a total of 30 individuals from 2 populations), also possessed 
this haplotype (Stamford and Taylor 2004, p. 1538).
    Variation in mtDNA haplotypes based on sequencing a portion of the 
`control region' of the mtDNA molecule of Arctic grayling from 26 
different populations seems to support the groupings proposed by 
Stamford and Taylor (2004, entire) (USFWS unpublished data). Two 
haplotypes were common in the five native Missouri River populations 
(Big Hole, Red Rock, Madison, Miner, and Mussigbrod - total sample size 
143 individuals; USFWS unpublished data). Fish from three populations 
in Saskatchewan or near Hudson's Bay also had one of these Missouri 
River haplotypes at very high frequency (50 of 51 individuals sequenced 
had the same haplotype; USFWS unpublished data). The two ``common'' 
Missouri River haplotypes also occurred at low frequency in handful of 
other populations elsewhere in Canada and Alaska. For example, there a 
total of five such populations where a few individuals contained had 
one or the other of the two common Missouri River haplotypes (25 of 107 
individuals sequenced; USFWS unpublished data). Also similar to the 
earlier study by Stamford and Taylor (2004, entire), a few individuals 
(9 of 40 individuals) from two populations from the Lower Peace River 
and the Upper Yukon River also had one or the other of the two common 
Missouri River haplotypes (USFWS unpublished data).
    The distribution of the common Missouri River haplotype compared to 
others suggested 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 2006, 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 of 
one or the other of the `Missouri River' haplotypes in 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 that exhibit tandem repeats of DNA base pairs) that 
included samples from five native Missouri River populations and two 
from Saskatchewan showed substantial divergence between these groups 
(Peterson and Ardren 2009, entire). Genetic differentiation between 
sample populations can be compared in terms of the genetic variation 
within relative to among populations, measured in terms of allele 
frequencies, 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 (all genetic diversity within a 
species is shared by all populations), whereas a value of 1 indicates 
the populations are completely different (all the genetic diversity 
within a species is found as fixed differences among populations). 
Fst values ranged 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 ranged from 0.47 to 
0.71 (average 0.54) for the same comparisons (Peterson and Ardren 2009, 
pp. 1758, 1764-1765). This indicates that the two groups (Missouri vs. 
Saskatchewan populations) differ significantly in allele frequency and 
also in the size differences, and therefore divergence, among those 
alleles. This indicates that the observed genetic differences are not 
simply due to random loss of genetic variation because the populations 
are isolated (genetic drift), but they also are due to mutational 
differences, which suggests the groups may have been separated for 
millennia (Peterson and Ardren 2009, pp. 1767-1768).
    Comparison of 435 individuals from 21 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). A 
statistical analysis that determines the likelihood that an individual 
fish belongs to a particular group (e.g., STRUCTURE) (Pritchard et al. 
2000, entire), clearly separated the 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). Factorial 
correspondence analysis (FCA) plots of individual fish also separated 
the fish

[[Page 54721]]

into two groups, or clouds of data points when visualized in a three-
dimensional space (USFWS, unpublished data). The FCA is a multivariate 
data analysis technique used to simplify presentation of complex data 
and to identify systematic relations between variables, in this case 
the multi-locus genotypes of Arctic grayling. As with the other 
analysis, the FCA plots clearly distinguished Missouri River Arctic 
grayling from those native to Canada and Alaska (USFWS, unpublished 
data). Divergence in size among these alleles further supports the 
distinction between Missouri River grayling from 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 most 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 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 Red Rock Lakes drainage 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 
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 ESA 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 ESA 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.
Conclusion
    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 indicates that Arctic grayling in the 
Missouri River basin have been separated from other populations for 
thousands of years. The population segment occurs in an ocean drainage 
different from 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. We conclude that because Arctic 
grayling of the upper Missouri River basin satisfy the criteria for 
being discrete and significant under our DPS policy, we determined that 
this population constitutes a DPS under our policy and the Act.
    In our stipulated settlement agreement, we also agreed to consider 
the appropriateness of distinct population segments based on the two 
different ecotypes (fluvial and adfluvial) expressed by native Arctic 
grayling of the upper Missouri River. We acknowledge there are cases 
where the Service has designated distinct population segments primarily 
on life-history even when they co-occur with another ecotype that can 
be part of the same gene pool (e.g., anadromous steelhead and resident 
rainbow trout, Oncorhynchus mykiss (71 FR 838, January 5, 2006). 
However, we conclude that designation of a single population segment 
for Arctic grayling in the upper Missouri River is more appropriate 
than designating two separate distinct population segments delineated 
by life-history type. In the Missouri River basin, the two ecotypes 
share a common evolutionary history, and do not cluster genetically 
based strictly on ecotype. As we discussed above, the fluvial and 
adfluvial life-history forms of Arctic grayling in the upper Missouri 
River do not appear to represent distinct evolutionary lineages. There 
appears to be some plasticity in behavior where individuals from a 
population can exhibit a range of behaviors. From a practical 
standpoint, we observe that only five native Arctic grayling 
populations remain in the Missouri River basin, and we believe that 
both fluvial and adfluvial native ecotypes have a role in the 
conservation of the larger population segment. We believe that the 
intent of the ESA and the DPS policy, and our obligation to assess the 
appropriateness of alternate DPS designations in the settlement 
agreement are best served by designating a single distinct population 
segment, rather than multiple population segments.
    As we described above, we are not including introduced populations 
that occur in lakes in the Upper Missouri River basin in the DPS. The 
Service has interpreted the Act to provide a statutory directive to 
conserve species in their native ecosystems (49 FR 33890,

[[Page 54722]]

August 27, 1984) and to conserve genetic resources and biodiversity 
over a representative portion of a taxon's historical occurrence (61 FR 
4723, February 7, 1996). The introduced Arctic grayling occur in lakes 
apart from native fluvial environments and from lakes where native 
adfluvial grayling occur. These introduced populations have not been 
used for any conservation purpose and could pose genetic risks to the 
native Arctic grayling population.
    We find that the Arctic grayling of the upper Missouri River basin 
constitute a distinct population segment. 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, 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 Red Rock Lakes. We refer to this DPS 
as the native Arctic grayling of the upper Missouri River. The 
remainder of this finding will thus focus on the population status of 
and threats to this entity.

Population Status and Trends for Native Arctic Grayling in the Upper 
Missouri River

    We identified a DPS for Arctic grayling in the upper Missouri River 
basin that includes five extant populations: (1) Big Hole River, (2) 
Miner Lake, (3) Mussigbrod Lake, (4) Madison River-Ennis Reservoir, and 
(5) Red Rock Lakes. In general, we summarize what is known about the 
historical distribution and abundance of each of these populations, 
describe their current distributional extent, summarize any available 
population monitoring data, identify the best available information 
that we use to infer the current population status, and summarize the 
current population status and trends.

   TABLE 4. Extent and current estimated effective population sizes (Ne) of native Arctic grayling populations in the Missouri River basin. Values in
                                                 parentheses represent 95 percent confidence intervals.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                           Estimated Adult Population Size Assuming:
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Biological Date of
             Population Name                  Population            Ne \b\          Population Size      Ne/N ratio 0.25 \d\       Ne/N ratio 0.14 \e\
                                               Extent\a\                                  \c\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Big Hole River                                       158 mi    208 (176 to 251)           2000-2003        828 (704 to 1,004)    1,486 (1,257 to 1,793)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Miner Lakes                                         26.9 ha   286 (143 to 4,692)          2001-2003     1,144 (572 to 18,768)   2,043 (1,021 to 33,514)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mussigbrod Lake                                     42.5 ha       1,497 (262 to           2001-2003   5,988 (1,048 to [infin])         10,693 (1,871 to
                                                                       [infin])                                                                [infin])
--------------------------------------------------------------------------------------------------------------------------------------------------------
Madison River-Ennis Reservoir                      1,469 ha          162 (76 to           1991-1993      648 (304 to [infin])    1,157 (543 to [infin])
                                                                       [infin])
--------------------------------------------------------------------------------------------------------------------------------------------------------
Red Rock Lakes                                       890 ha    228 (141 to 547)           2000-2002        912 (564 to 2,188)    1,629 (1,007 to 3,907)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Approximate maximum spatial extent over which Arctic grayling are encountered in a given water.
\b\ Effective population size estimates from Peterson and Ardren (2009, p.1767). Confidence intervals that include infinity ([infin]) can result from
  statistical artifacts of the linkage disequilibrium method (Waples and Do 2007, p. 10; Russell and Fewster 2009, pp. 309-310). The usual
  interpretation is that there is no evidence for any disequilibrium caused by genetic drift due to a finite number of parents--it can all be explained
  by sampling error (Waples and Do 2007, p. 10). Thus, the effective size is infinitely large. Small sample sizes may influence estimates in some cases
  (e.g., Madison River-Ennis Reservoir).
\c\ Approximate date to which the Ne estimate refers. For example, Ne for the Big Hole River based on genotyping a sample of fish from 2005-2006, but
  the interpretation of Ne is the number of breeding adults that produced the fish in the observed sample. Thus the true biological date of the Ne
  estimate is one generation before 2005-2006, or approximately 2000-2003.
\d\ Adult population size estimated from Ne assuming Ne /N = 0.25. This value was the midpoint of a range of values (0.2-0.3) commonly cited for Ne /N
  ratios in salmonid fishes (Allendorf et al. 1997, p. 143; McElhahey et al. 2000, p. 63; Rieman and Allendorf 2001, p. 762; Palm et al. 2003, p. 260).
\e\ Adult population size estimated from Ne assuming Ne /N = 0.14. This value was the median Ne /N ratio based on a meta analysis of 83 studies for 65
  different species (Palstra and Ruzzante 2008, p. 3428).

Big Hole River

    Historically, Arctic grayling presumably had access to and were 
distributed throughout much of the Big Hole River, including the lower 
reaches of many tributary streams, such as Big Lake, Deep, Doolittle, 
Fishtrap, Francis, Governor, Johnson, LaMarche, Miner, Mussigbrod, 
Odell, Pintlar, Rock, Sand Hollow, Swamp, Seymour, Steel, Swamp, and 
Wyman Creeks, as well as the Wise River (Liknes 1981, p. 11; Liknes and 
Gould 1987, p. 124; Kaya 1990, pp. 36-40). Presently, Arctic grayling 
are found primarily in the mainstem Big Hole River between the towns of 
Glen and Jackson, Montana, a distance of approximately 181 river km 
(113 mi), and in 11 tributaries, totaling an additional 72 river km (45 
mi) (Magee 2010a, pers. comm.; see Table 4 above). The total current 
maximum extent of Arctic grayling occurrence in the Big Hole River is 
approximately 250 river km (156 mi). However, the fish are not 
continuously distributed across this distance, and instead tend to be 
concentrated in discrete patches (Magee et al. 2006, pp. 27-28; Rens 
and Magee 2007, p. 15) typically associated with spawning and rearing 
habitats or cold-water sites that provide a thermal refuge from high 
summer water temperatures.
    Kaya (1992, pp. 50-52) noted the general lack of monitoring data 
for the Big Hole River fluvial Arctic grayling population prior to the 
late 1970s, but data collected since that time indicate the overall 
range has contracted over the last 2 decades. During 1978 and 1979 
Arctic grayling were observed in Governor Creek (in the headwaters of 
the Big Hole River) and downstream in the Big Hole River near Melrose, 
Montana (Liknes 1981, p. 11). Arctic grayling have not recently been 
encountered in Governor Creek (Rens and Magee 2007, p. 15; Montana 
Fish, Wildife and Parks (MFWP), unpublished data), but are occasionally

[[Page 54723]]

encountered in the Big Hole River downstream of Divide, Montana, at 
very low densities and as far downstream as Melrose or Glen, Montana 
(Oswald 2005a, pers. comm.). More recently, Arctic grayling have become 
less abundant in historical spawning and rearing locations in the upper 
watershed near Wisdom, Montana, and also in downstream river segments 
with deep pool habitats considered important for overwintering (Magee 
and Lamothe 2003, pp. 18-21; MFWP unpublished data). Comparatively, 
greater numbers of Arctic grayling are encountered in the lower reaches 
of tributaries to the upper Big Hole River, including LaMarche, 
Fishtrap, Steel, and Swamp Creeks (Rens and Magee 2007, p. 13).
    Based on the best available data, the adult population declined by 
one half between the early 1990s and the early 2000s (see Figure 3, 
USFWS unpublished data), which is equivalent to a decline of 7 percent 
per year, on average. Monitoring data collected by MFWP also support 
the conclusion that the Arctic grayling population in the Big Hole 
River declined during this time period (Byorth 1994a, p. 11; Rens and 
Magee 2007, entire; MFPW, unpublished data).
[GRAPHIC] [TIFF OMITTED] TP08SE10.002

    FIGURE 3. Effective population size (Ne) of Big Hole 
River Arctic grayling based on microsatellite DNA genotypes from fish 
collected in three time periods (USFWS, unpublished data). The 
Ne are estimated using the linkage disequilibrium method of 
Waples and Do (2008, entire), and error bars represent 95% confidence 
intervals estimated by the jackknife method.

Miner Lakes

    The Miner Lakes are a complex of small lakes in the upper Big Hole 
River drainage. Lower Miner Lakes are two small lakes in the middle of 
the Miner Creek drainage connected by a narrow section approximately 
100 m (330 ft) in length, functionally representing a single lake for 
fish populations. Arctic grayling occur in Lower Miner Lakes (hereafter 
Miner Lakes population), which has a total surface area of 26.7 
hectares (ha) or 0.267 km\2\ (66 acres (ac)). Arctic grayling primarily 
reside in the lake, and presumably move into the inlet or outlet 
tributary to spawn. Surveys conducted upstream and downstream of the 
Lower Miner Lakes in 1992 and 1994, respectively, captured no Arctic 
grayling (Downing 2006, pers. comm.). Apparently, adults do not remain 
in the stream long after spawning and young-of-the-year (YOY) move into 
Lower Miner Lakes.
    The MFWP conducted limited surveys in Lower Miner Lakes, but the 
abundance of the population has not been estimated by traditional 
fishery methods. Arctic grayling are classified as ``common'' in Lower 
Miner Lakes (MFISH 2010). Introduced brook trout also are present.
    The best available information on the abundance of Miner Lakes 
Arctic grayling comes from a genetic assessment of that population. 
Based on a sample of fish from 2006, Peterson and Ardren (2009, p. 
1767) estimated an effective population size of 286. This estimate 
represents an approximation of abundance of breeding adults at a single 
point in time, and there are no data on which to base an assessment of 
the population trend.

Mussigbrod Lake

    Mussigbrod Lake has a surface area of 42.5 ha (105 ac), and is 
found in the middle reaches of Mussigbrod Creek, a tributary to the 
North Fork Big Hole River. Arctic grayling primarily reside in the 
lake. We do not know whether Arctic grayling spawn in the inlet stream 
or within the lake (Magee and

[[Page 54724]]

Olsen 2010, pers. comm.). Arctic grayling occasionally pass over a 
diversion structure downstream at the outlet of Mussigbrod Lake, and 
become trapped in a pool that is isolated because of stream dewatering. 
The MFWP periodically capture grayling in this pool and return them to 
the lake.
    Data for the Mussigbrod Lake population of Arctic grayling is 
minimal. The MFWP has conducted very limited surveys and the abundance 
of the population has not been estimated by traditional fishery 
methods. Genetic data indicate that Arctic grayling are comparatively 
abundant (see Table 4 above). Based on a sample from 2006, Peterson and 
Ardren (2009, p. 1767) estimated an effective size of 1,497. The best 
available data indicate that the Mussigbrod Lake population is 
comparatively large, but we have no data about the population trend.

Madison River - Ennis Reservoir

    Historically, Arctic grayling were reported to be abundant in the 
middle and upper Madison River, but have undergone a dramatic decline 
in the past 100 years with the species becoming rare by the 1930s 
(Vincent 1962, pp. 11, 85-87). Native Arctic grayling are thought be 
extirpated from the upper Madison River. A major impact to fish in that 
area was the construction of Hebgen Dam, which flooded Horsethief 
Springs, a small tributary that was reportedly one of the most 
important streams for Arctic grayling (Vincent 1962, pp. 40-41, 128). 
In the middle Madison River, Arctic grayling were apparently common to 
plentiful in the mainstem River near Ennis, Montana, and some 
associated tributaries (Jack, Meadow, and O'Dell Creeks) (Vincent 1962, 
p. 128). In 1906, construction of Ennis Dam blocked all upstream 
movement of fishes, and apparently had a large negative effect on 
Arctic grayling. Vincent (1962) noted that ``early settlers reported 
scooping up boxes full of grayling at the base of Ennis Dam the year 
after it was constructed'' (p. 128), and that the species apparently 
became quite rare by the late 1930s (Vincent 1962, p. 85).
    The current distribution of Arctic grayling in the Madison River is 
primarily restricted to the Ennis Reservoir and upstream into the river 
approximately 6.5 km (approximately 4 mi) to the Valley Garden Fishing 
Access Site (Byorth and Shepard 1990, p. 21). Arctic grayling are 
occasionally encountered in the Madison River downstream and upstream 
from Ennis Reservoir (Byorth and Shepard 1990, p. 25; Clancey 2004, p. 
22; 2008, p. 21). Arctic grayling migrate from the reservoir into the 
river to spawn, then return to the reservoir (Byorth and Shepard 1990, 
pp. 21-22; Rens and Magee 2007, pp. 20-21). The YOY Arctic grayling 
spawned in the Madison River migrate downstream into Ennis Reservoir 
about 1 month after emergence, but while they are in the river, they 
are typically encountered in backwater or slackwater habitat (Jeanes 
1996, pp. 31-34).
    The MFWP has sporadically monitored Arctic grayling in the Madison 
River near Ennis Reservoir since about 1990. Despite sparse data, 
declining catches for both spawning adults and YOY indicate the 
population is less abundant now compared to the early 1990s. The 
highest numbers of YOY Arctic grayling were encountered in the early 
1990s, and no more than two have been captured in any given year since 
that time. Our interpretation of this information is that Arctic 
grayling in the Madison River-Ennis Reservoir population have declined 
during the past 20 years and are presently at very low abundance.
    Abundance of the Madison River-Ennis Reservoir Arctic grayling has 
been estimated twice. In 1990, the adult population was estimated to be 
545, but the authors cautioned that the accuracy of the estimate was 
questionable as it was based on recapturing only. From a sample of fish 
collected mostly in 1996, the effective size of the population 
(breeding adults) was estimated as 162 (Peterson and Ardren 2009, p. 
1767). The average number of Arctic grayling captured per unit effort 
(CPUE) declined by approximately a factor of 10 between the early 1990s 
and recent samples (Clancey 1998, p. 10; Clancey 2007, p.16; Clancey 
2008, pp. ii, 21, A2-2; Clancey and Lohrenz 2009, pp. 30, B2; Clancey 
2010a, pers. comm.; Clancey 2010b, pers. comm.). Adult Arctic grayling 
may currently exist at only 10 to 20 percent of the abundance observed 
in the early 1990s. Based on the best available data, we conclude that 
this Arctic grayling population has been in a decline during the past 
20 years and may only consist of a few hundred adults.

Red Rocks Lakes

    Arctic grayling are native to waters of the upper Beaverhead River 
system, including the Red Rock River drainage. During the past 50 to 
100 years, both the distribution and abundance of Arctic grayling in 
the Centennial Valley, Beaverhead County, Montana (which contains the 
Red Rock River), has severely declined (Vincent 1962, pp. 115-121; 
Unthank 1989, pp. 13-17; Mogen 1996, pp. 2-5, 75-84). As of about 50 
years ago, Arctic grayling spawned in at least 12 streams in the 
Centennial Valley (Mogen 1996, p. 17), but they appear to have been 
extirpated from all but 2 streams (Boltz 2006, p. 6). Presently, Arctic 
grayling spawn in two locations within the Red Rock River drainage: 
Odell Creek, a tributary to Lower Red Rock Lake; and Red Rock Creek, 
the primary tributary to Upper Red Rock Lake (Mogen 1996, pp. 47-48; 
Boltz 2006, p. 1). Lower and Upper Red Rock Lakes are connected by a 
short segment of river, and both lakes are contained within the 
boundaries of the Red Rock Lakes National Wildlife Refuge (NWR). The 
upper lake appears to be the primary rearing and overwintering habitat 
for Arctic grayling. Red Rock Creek is the only stream where Arctic 
grayling spawn in appreciable numbers (Mogen 1996, pp. 45-48). 
Collectively, we refer to this population as the Red Rocks Lakes Arctic 
grayling, and characterize it as having the adfluvial ecotype.
    Arctic grayling in the Red Rock Lakes have been monitored 
intermittently since the 1970s. Most of that effort focused on Red Rock 
Creek, but periodic sampling also occurred in Odell Creek. The MFWP and 
the Service occasionally sampled for Arctic grayling in Odell Creek, 
where grayling abundance declined over the past few decades. On 
average, the minimum sizes of the spawning runs in Red Rock Creek since 
1994 are about half of those recorded 4 decades ago (i.e., 623 vs. 308 
per year) (data summarized from Mogen 1996, p. 70 and Boltz 2006, p. 
7). The spawning runs into Red Rock Creek fluctuated during the 1990s 
and early 2000s, but about 450 or fewer adult Arctic grayling have been 
captured in 6 of 7 years in which weirs traps were operated. 
Electrofishing surveys conducted in Red Rock Creek by MFWP seem to 
corroborate a decline in the spawning population, as total catches 
decreased even as sampling effort increased (Rens and Magee 2007, pp. 
16-18).
    Based on a sample of fish from Red Rock Creek in 2005, Peterson and 
Ardren (2009, pp. 1761, 1767) estimated an effective size of 228, which 
is interpreted as the number of breeding adults that produced the fish 
sampled in 2005. The best available data indicate that the Red Rock 
Lakes Arctic grayling population has declined over the past 2 decades.

Population viability analysis (PVA) of native Missouri River Arctic 
grayling

    To gauge the probability that the different native populations of 
Arctic grayling in the upper Missouri River

[[Page 54725]]

basin will go extinct from unpredictable events in the foreseeable 
future, we conducted a simple population viability analysis (PVA) (see 
Dennis et al. (1991, entire) in Morris and Doak 2002, pp. 85-87 for 
details on the PVA model and the software code to run the model). We 
assumed that a population with 50 or fewer adults is likely influenced 
by demographic stochasticity (chance variation in the fates of 
individuals within a given year) and genetic stochasticity (random 
changes in a population's genetic makeup), and would not be expected to 
persist long as a viable population. For the different PVA scenarios, 
we assume either the population has stabilized, or the estimated 
decline will continue at a constant rate.
    We considered the probability of extinction individually by 
population, as populations appear to be reproductively isolated. The 
relative risk of extinction in the foreseeable future (30 years based 
on the observation that the variability in predictions for extinction 
risk from the PVA model increases substantially after 30 years) varies 
among the different populations, with the largest population, 
Mussigbrod Lake, having a very low probability of extinction (less than 
1 percent) in the foreseeable future, even given a population decline. 
The other four populations have comparatively greater probabilities of 
extinction in the foreseeable future, with all being roughly similar in 
magnitude (13-55 percent across populations) when considering only 
stochastic (random or chance) processes. The Madison River has the 
greatest probability of extinction by stochastic processes (36-55 
percent), followed by Big Hole (33-42 percent), Red Rocks (31-40 
percent), and Miner (13-37 percent).
    Overall, the PVA analyses indicate that four populations (Madison, 
Big Hole, Red Rocks, and Miner) appear to be at risk from chance 
environmental variation because of low population abundance. This is a 
general conclusion, and the actual risk may vary substantially among 
populations (USFWS unpublished data). For example, Arctic grayling in 
the Big Hole River population spawn in different locations, which would 
reduce the risk that an environmental catastrophe would simultaneously 
kill all breeding adults, relative to a situation where adults appear 
to be primarily in a single location or reach of river (e.g., Red Rocks 
and Madison populations).

Arctic Grayling Conservation Efforts

Native Arctic Grayling Genetic Reserves and Translocation

    Given concern over the status of native Arctic grayling, the 
Montana Arctic Grayling Recovery Program (AGRP) was formed in 1987, to 
address conservation concerns for primarily the fluvial ecotype in Big 
Hole River, and to a lesser extent the native adflvuial population in 
Red Rock Lakes (Memorandum of Understanding (MOU) 2007, p. 2). The AGW 
was established as an ad hoc technical workgroup of the AGRP. In 1995, 
the AGW finalized a restoration plan that outlined an agenda of 
restoration tasks and research, including management actions to secure 
the Big Hole River population, brood stock development, and a program 
to re-establish four additional fluvial populations (AGW 1995, pp. 7-
17).
    Consequently, the State of Montana established genetic reserves of 
Big Hole River grayling (Leary 1991, entire), and has used the progeny 
from those reserves in efforts to re-establish additional fluvial 
populations within the historical native range in the Missouri River 
basin (Rens and Magee 2007, pp. 21-38). Currently, brood (genetic) 
reserves of Big Hole River grayling are held in two closed-basin lakes 
in south-central Montana (Rens and Magee 2007, p. 22). These fish are 
manually spawned to provide gametes for translocation efforts in 
Montana (Rens and Magee 2007, p. 22). Functionally, these brood 
reserves are hatchery populations maintained in a natural setting, and 
we do not consider them wild populations for the purposes of evaluating 
the status of native Arctic grayling in the Missouri River basin. 
However, they are important to recovery efforts.
    For more than 13 years, MFWP has attempted to re-establish 
populations of fluvial Arctic grayling in various locations in the 
Missouri River basin, including the Ruby, Sun, Beaverhead, Missouri, 
Madison, Gallatin, and Jefferson Rivers (Lamothe and Magee 2004a, pp. 
2, 28). A self-sustaining population has not yet been established from 
these reintroductions (Lamothe and Magee 2004a, p. 28; Rens and Magee 
2007, pp. 35-36, 38). Recent efforts have focused more intensively on 
the Ruby and Sun Rivers, and have used methods that should improve 
reintroduction success (Rens and Magee 2007, pp. 24-36). Encouragingly, 
natural reproduction by Arctic grayling in the Ruby River was confirmed 
during fall 2009 (Magee 2010b, pp. 6-7, 22). Monitoring will continue 
in subsequent years to determine whether the population has become a 
stable and viable population, as defined by the guidance and 
implementation documents of the translocation programs (AGW 1995, p. 1; 
Memorandum of Agreement (MOA) 1996, p. 2). Consequently, we do not 
consider the Ruby River to represent a self-sustaining population for 
the purposes of evaluating the population status of Missouri River 
grayling in this finding. Arctic grayling presumably from previous 
translocations are occasionally encountered near translocation sites in 
other waters (Rens and Magee 2007, pp. 35-38; MFWP, unpublished data). 
There is no evidence that these individuals represent progeny from a 
re-established population, so we cannot consider them elements of a 
stable and viable population for the purposes of evaluating the 
population status of Missouri River Arctic grayling in this finding.

Big Hole River Candidate Conservation Agreement with Assurances

    On August 1, 2006, the Service issued ESA section 10(a)(1)(A) 
enhancement of survival permit (TE-104415-0) to Montana Fish, Wildlife 
and Parks (MFWP) to implement a Candidate Conservation Agreement with 
Assurances for Arctic grayling in the upper Big Hole River (Big Hole 
Grayling CCAA) (MFWP et al. 2006, entire). This permit is valid through 
August 1, 2026. The goal of the Big Hole Grayling CCAA is to secure and 
enhance a population of fluvial Arctic grayling within the upper 
reaches of their historic range in the Big Hole River drainage by 
working with non-Federal property owners to implement conservation 
measures on their lands. The guidelines of this CCAA will be met by 
implementing conservation measures that improve stream flows, protect 
and restore riparian habitats, identify and reduce or eliminate 
entrainment (inadvertent capture) of grayling in irrigation ditches, 
and remove human-made barriers to grayling migration (MFWP et al. 2006, 
p. 3). Currently, 32 landowners representing 64,822 ha (160,178 ac) in 
the upper Big Hole River drainage are participating in the CCAA 
(Lamothe 2009, p. 5). The MFWP leads the Big Hole Grayling CCAA 
implementation effort, and is supported by Montana Department of 
Natural Resources and Conservation (MDNRC), USDA Natural Resources 
Conservation Service (NRCS), and the Service. Other groups helping 
implement the CCAA include the Big Hole Watershed Committee, the Big 
Hole River Foundation, Montana Trout Unlimited, the Western Water 
Project (affiliated with Trout Unlimited), and

[[Page 54726]]

The Nature Conservancy (Lamothe 2008, p. 23). Detailed information on 
conservation actions and restoration projects implemented under the 
plan are available in various reports (AGW 2010, p. 4; Everett 2010, 
entire; Lamothe et al. 2007, pp. 6-35; Lamothe 2008, pp. 7-21; Lamothe 
2009, entire; Lamothe 2010, entire; Magee 2010b, entire; Roberts 2010, 
entire).

Biological Effectiveness of the Ongoing Conservation Programs

    The current and anticipated effects of the aforementioned 
conservation programs on the biological status and threats to Arctic 
grayling of the upper Missouri River are discussed elsewhere in the 
document (see Summary of Information Pertaining to the Five Factors and 
Finding sections, below). We continue to encourage and promote 
collaborative efforts to secure existing populations, and to increase 
the distribution of the Arctic grayling within its historical range in 
the upper Missouri River basin.

Summary of Information Pertaining to the Five Factors

    Section 4 of the ESA (16 U.S.C. 1533) and implementing regulations 
(50 CFR 424) set forth procedures for adding species to the Federal 
Lists of Endangered and Threatened Wildlife and Plants. Under section 
4(a)(1) of the ESA, 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 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 to a species, 
we must look beyond the exposure of the species to a factor to evaluate 
whether the species may respond to the factor in a way that causes 
actual impacts to the species. If there is exposure to a factor and the 
species responds negatively, the factor may be a threat and we attempt 
to determine how significant a threat it is. The threat is significant 
if it drives, or contributes to, the risk of extinction of the species 
such that the species warrants listing as endangered or threatened as 
those terms are defined in the Act.

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

Curtailment of Range and Distribution

    The number of river kilometers (miles) occupied by the fluvial 
ecotype of Arctic grayling in the Missouri River has been reduced by 
approximately 95 percent during the past 100 to 150 years (Kaya 1992, 
p. 51). The fluvial life history is only expressed in the population 
residing in the Big Hole River; the remnant population in the Madison 
River near Ennis Reservoir has apparently diverged toward an adfluvial 
life history. Arctic grayling distribution within the Centennial Valley 
in the upper Beaverhead River also has been severely curtailed during 
the last 50 to 100 years, such that the only remaining example of the 
species in that drainage is an adfluvial population associated with the 
Red Rock Lakes. Indigenous populations in the Big Hole River, Madison 
River, and Red Rock Lakes all exist at reduced densities on both 
contemporary and historical timescales. The Miner Lakes and Mussigbrod 
Lake populations appear to have been reproductively isolated for 
hundreds of years (USFWS, unpublished data), so a restricted 
distribution may represent the natural historical condition for these 
populations. The curtailment of range and distribution is a current 
threat, because the probability of extirpation of the DPS is related to 
the number of populations and their resilience. Since the DPS currently 
exists as a set of generally small, isolated populations that cannot 
naturally re-found or `rescue' another population. Thus, the 
curtailment of range and distribution will remain a threat in the 
foreseeable future, absent the reestablishment of additional 
populations within the DPS' historical range. Reintroduction attempted 
under the auspices of the 1995 Restoration Plan (AGW 1995, entire) have 
been underway since 1997, but have not yet resulted in re-establishment 
of populations or the expansion of the DPS' current range.

Dams on Mainstem Rivers

    The majority of the historical range of the Upper Missouri River 
DPS of Arctic grayling has been altered by the construction of dams and 
reservoirs that created barriers obstructing migrations to spawning, 
wintering, or feeding areas; inundated grayling habitat; and impacted 
the historical hydrology of river systems (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 migratory life histories. Construction 
of dams that obstructed fish passage on the mainstem Missouri River 
(Hauser, Holter, Canyon Ferry, and Toston), Madison River (Madison-
Ennis, Hebgen), Beaverhead River and its tributary Red Rock River 
(Clark Canyon, Lima), Ruby River (Ruby), and Sun River (Gibson) all 
contributed to the rangewide decline of this DPS (Vincent 1962, pp. 
127-128; Kaya 1992, p. 57; see Figure 2).
    Dams also may continue to impact the extant population in the 
Madison River. The Madison Dam (also known as Ennis Dam), as with the 
aforementioned dams, is a migration barrier with no fish passage 
facilities. Anglers have reported encountering Arctic grayling in pools 
below the dam, implying that fish occasionally pass (downstream) over 
or through the dam. These fish would be ``lost'' to the population 
residing above the dam because they cannot return upstream, but have 
apparently not established populations downstream. Operational 
practices of the Madison Dam also have been shown to affect the 
resident fishes. A population decline of Arctic grayling coincided with 
a reservoir drawdown in winter 1982-1983 that was intended to reduce 
the effects of aquatic vegetation on the hydroelectric operations at 
the dam (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.
    The presence of mainstem dams is a historical, current, and future 
threat to the DPS. Lack of fish passage at these dams contributed to 
the extirpation of 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). These dams are an 
impediment to fish migration and limit the ability of fish to disperse 
between existing populations or recolonize habitat fragments, and will 
continue to act in this manner for the foreseeable future. We believe 
the presence of a mainstem dam is an immediate and imminent threat to 
the Madison River population, as the remaining grayling habitat is 
adjacent to Ennis Dam (see Figure 2). We not aware of any plans to 
retrofit the Ennis Dam or any other mainstem dam to provide upstream 
fish passage, so we expect the current situation to continue. The 
Federal Energy Regulatory Commission (FERC) license for hydroelectric 
generation at Ennis Dam will not expire until the year

[[Page 54727]]

2040 (FERC 2010, entire). The upper Missouri River basin dam having the 
FERC license with the latest expiration date is Clark Canyon Dam, which 
will not expire until 2059 (FERC 2010, entire). Thus, mainstem dams 
will remain a threat in the foreseeable future, which is 30 to 50 years 
based on the duration of existing FERC licenses in the upper basin.

Agriculture and Ranching

    The predominant use of private lands in the upper Missouri River 
basin is irrigated agriculture and ranching, and these activities had 
and continue to have significant effects on aquatic habitats. In 
general, these effects relate to changes in water availability and 
alteration to the structure and function of aquatic habitats. The 
specific activities and their impacts are discussed below.

Smaller Dams and Fish Passage Barriers

    Smaller dams or diversions associated with irrigation structures 
within specific watersheds continue to pose problems 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. The 
Divide Dam on the Big Hole River near the town of Divide, Montana, has 
existed for nearly 80 years and is believed to be at least a partial 
barrier to upstream movement by fishes (Kaya 1992, p. 58). 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). A number of planned or ongoing 
conservation actions to address connectivity issues on the Big Hole 
River and its tributaries may reduce the threat posed by movement 
barriers for Arctic grayling in that habitat. The Divide Dam is being 
replaced with a new structure that provides fish passage, and 
construction began in July 2010 (Nicolai 2010, pers. comm.). At least 
17 fish ladders have been installed at diversion structures in the Big 
Hole River since 2006 as part of the Big Hole Grayling CCAA (AGW 2010, 
p. 4), and a culvert barrier at a road crossing on Governor Creek 
(headwaters of Big Hole River) was replaced with a bridge that is 
expected to provide upstream passage for aquatic organisms under all 
flow conditions (Everett 2010, pp. 2-6). Non-Federal landowners who 
control approximately 50 to 70 percent of the points of irrigation 
diversion in the upper Big Hole River are enrolled in the CCAA (Roberts 
and Lamothe 2010, pers. comm.), so the threats posed by fish passage 
barriers should be substantially reduced in the Big Hole River during 
the next 10 to 20 years (foreseeable future) based on the minimum 
duration of site-specific plans for landowners enrolled in the CCAA and 
the duration of the ESA section 10(a)(1)(A) enhancement of survival 
permit (TE 104415-0) associated with the CCAA (MFWP et al. 2006, p. 
75).
    Fish passage barriers also have been noted in the Red Rock Lakes 
system (Unthank 1989, p. 9). Henshall (1907, p. 5) noted that 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. The 
construction of a water control structure (sill) at the outlet of Lower 
Red Rock Lake in 1930 (and reconstructed in 1957 (USFWS 2009, p. 74)) 
created an upstream migration barrier that blocked these migrations 
(Unthank 1989, p. 10; Gillin 2001, p. 4-4). This structure, along with 
mainstem dams at Lima and Clark Canyon, extirpated spawning runs of 
Arctic grayling that historically migrated through the Beaverhead and 
Red Rock Rivers (see Figure 2; USFWS 2009, p. 72). All of these 
structures preclude upstream movement by fishes, and continue to 
prohibit immigration of Arctic grayling from the Big Hole River (see 
Figure 2). Because recovery of Arctic grayling will necessitate 
expansion into unoccupied habitat, and the Big Hole River includes some 
of the best remaining habitat for the species, these dams constitute a 
threat to Arctic grayling now and in the foreseeable future, which is 
30 to 50 years based on the duration of existing FERC licenses in the 
upper basin.
    In Mussigbrod Lake, Arctic grayling occasionally pass downstream 
over a diversion structure at the lake outlet, and become trapped in a 
pool that is isolated because of stream dewatering (Magee and Olsen 
2010, pers. comm.). However, the potential for mortality in these fish 
is partially mitigated by MFWP, which periodically captures Arctic 
grayling in this pool and returns them to the lake.
    In the Red Rock Lakes system, the presence of fish passage barriers 
represents a past and present threat. The magnitude of the threat may 
be reduced in the next 15 years as a result of implementation of the 
Red Rock Lakes NWR Comprehensive Conservation Plan (CCP) (USFWS 2009, 
entire -- see Factor D discussion below), but we conclude that not all 
barriers that potentially affect the population will addressed during 
this time (e.g., Lower Red Rock Lake Water Control Structure) (USFWS 
2009, p. 43). Thus, fish passage barriers will remain a threat to the 
Red Rock Lakes grayling in the foreseeable future.
    In the Big Hole River, fish passage barriers represent a past and 
present threat. The magnitude of the threat in the Big Hole River 
should decrease appreciably during the next 10 to 20 years, which 
represents the foreseeable future in terms of the potential for the Big 
Hole Grayling CCAA to address the threat. Additional projects, such as 
the replacement of the Divide Dam, also should reduce the threat in the 
foreseeable future.

Dewatering From Irrigation and Consequent Increased Water Temperatures

    Demand for irrigation water in the semi-arid upper Missouri River 
basin has dewatered many rivers formerly or currently occupied by 
Arctic grayling. The primary effects of this dewatering are: 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).
    In the Big Hole River system, surface-water (flood) irrigation has 
substantially altered the natural hydrologic function of the river and 
has led to acute and chronic stream dewatering (Shepard and Oswald 
1989, p. 29; Byorth 1993, p. 14; 1995, pp. 8-10; Magee et al. 2005, pp. 
13-15). Most of the Big Hole River mainstem exceeds water quality 
standards under the Clean Water Act (33. U.S.C. 1251 et seq.; see 
discussion under Factor D, below) because of high summer water 
temperatures (Flynn et al. 2008, p. 2). Stream water temperature is 
affected by flow volume, stream morphology, and riparian shading, along 
with other factors, but an inverse relationship between flow volume and 
water temperature is apparent in the Big Hole River (Flynn et al. 2008, 
pp. 18-19). Summer water temperatures exceeding 21 [deg]C (70 [deg]F) 
are

[[Page 54728]]

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 (Magee and Lamothe 2003, pp. 13-14; Magee et al. 
2005, p. 15; Rens and Magee 2007, p. 11). Recently, summer water 
temperatures have consistently exceeded the upper incipient lethal 
temperature (UILT) for Arctic grayling (e.g., 25 [deg]C or 77 [deg]F) 
(Lohr et al. 1996) at a number of monitoring stations throughout the 
Big Hole River (Magee and Lamothe 2003, pp. 13-14; Magee et al. 2005, 
p. 15; Rens and Magee 2007, p. 11). The UILT is the temperature that is 
survivable indefinitely (for periods longer than 1 week) by 50 percent 
of the ``test population'' in an experimental setting. Fish kills are a 
clear result of high water temperature and have been documented in the 
Big Hole River (Lohr et al. 1996, p. 934). Consequently, water 
temperatures that are high enough to cause mortality of fish in the Big 
Hole River represent a clear threat to Arctic grayling because of the 
potential to directly and quickly reduce the size of the population.
    Water temperatures below that which can lead to instant mortality 
also can affect individual fish. At water temperatures between 21 
[deg]C (70 [deg]F) and 25 [deg]C (77 [deg]F), Arctic grayling can 
survive but experience chronic stress that can impair feeding and 
growth, reduce physiological performance, and ultimately reduce 
survival and reproduction. As described above, the Big Hole River 
periodically experiences summer water temperatures high enough to cause 
morality and chronic stress to Arctic grayling. Increased water 
temperature also appears to be a threat to Arctic grayling in the 
Madison River and Red Rock watershed. Mean and maximum summer water 
temperatures can exceed 21 [deg]C (70 [deg]F) in the Madison River 
below Ennis Reservoir (U.S. Geological Survey (USGS) 2010), and have 
exceeded 22 [deg]C (72 [deg]F) in the reservoir, and 24 [deg]C (75 
[deg]F) in the reservoir inlet (Clancey and Lohrenz 2005, p. 34). 
Similar or higher temperatures have been noted at these same locations 
in recent years (Clancey 2002, p. 17; 2003, p. 25; 2004, pp. 29-30). 
Surface water temperatures in Upper Red Rock Lake as high as 24 [deg]C 
(75 [deg]F) have been recorded (Gillin 2001, p. 4-6), and presence of 
Arctic grayling in the lower 100 m (328 ft) of East Shambow Creek in 
1994 was attributed to fish seeking refuge from high water temperatures 
in the lake (Mogen 1996, p. 44). Mean summer water temperatures in Red 
Rock Creek can occasionally exceed 20[deg]C or 68[deg]F during drought 
conditions (Mogen 1996, pp. 19, 45). Arctic grayling can survive but 
experience chronic stress that can impair feeding and growth, reduce 
physiological performance, and ultimately reduce survival and 
reproduction.
    Experimental data specifically linking hydrologic alteration and 
dewatering to individual and population-level effects for Arctic 
grayling is generally lacking (Kaya 1992, p. 54), but we can infer 
effects from observations that the abundance and distribution of Arctic 
grayling has declined concurrent with reduced streamflows (MFWP et al. 
2006, pp. 39-40) and increased water temperatures associated with low 
streamflows.
    In the Big Hole River system, early-season (April through May) 
irrigation withdrawals may dewater grayling spawning sites (Byorth 
1993, p. 22), preventing spawning or causing egg mortality; can prevent 
juvenile grayling from accessing cover in the vegetation along the 
shoreline; and may reduce connectivity between necessary spawning, 
rearing, and refuge habitats. Severe dewatering reduces habitat volume 
and may concentrate fish, increasing the probability of competition and 
predation among and between species. Nonnative trout species presently 
dominate the salmonid community in the Big Hole River, so dewatering 
would tend to concentrate Arctic grayling in habitats where 
interactions with these nonnative trout would be likely.
    Especially in the Big Hole River, dewatering from irrigation 
represents a past and present threat to Arctic grayling. Thermal 
loading has apparently been a more frequent occurrence in the Big Hole 
River than in other locations containing native Arctic grayling (e.g., 
Red Rock Creek and Madison River-Ennis Reservoir). Implementation of 
the Big Hole Grayling CCAA during the next 20 years, which requires 
conservation measures to increase stream flows and restore riparian 
habitats (MFWP 2006, pp. 22-48), should significantly reduce the threat 
of thermal loading for Big Hole River grayling in the foreseeable 
future. While we expect agricultural and ranching-related use of water 
to continue, we expect that the threat will be reduced, but not 
eliminated, in the foreseeable future in the Big Hole River as a 
consequence of the CCAA. The ability of the Big Hole Grayling CCAA to 
augment streamflows should be substantial, as non-Federal landowners 
who control approximately 50 to 70 percent of the points of irrigation 
diversion in the upper Big Hole River are enrolled in the CCAA (Roberts 
and Lamothe 2010, pers. comm.). However, the Big Hole River constitutes 
one population in the DPS and high water temperatures are likely to 
continue to affect grayling in the Madison River and Red Rock Lakes. 
Thus, stream dewatering and high water temperatures are expected to 
remain a threat to the DPS in the foreseeable future.

Entrainment

    Entrainment can permanently remove individuals from the natural 
population and strand them in a habitat that lacks the required 
characteristics for reproduction and survival. Irrigation ditches may 
dry completely when irrigation headgates are closed, resulting in 
mortality of entrained grayling. Entrainment of individual Arctic 
grayling in irrigation ditches occurs in the Big Hole River (Skarr 
1989, p. 19; Streu 1990, pp. 24-25; MFWP et al. 2006, p. 49; Lamothe 
2008, p. 22). Over 1,000 unscreened diversion structures occur in the 
upper Big Hole River watershed, and more than 300 of these are located 
in or near occupied grayling habitat (MFWP et al. 2006, pp. 48-49).
    The magnitude of entrainment at unscreened diversions can depend on 
a variety of physical and biological factors, including the volume of 
water diverted (Kennedy 2009, p. iv, 36-38; but see Post et al. 2007, 
p. 885), species-specific differences in the timing of migratory 
behavior relative to when water is being diverted (Carlson and Rahel 
2007, pp. 1340-1341), and differences in vulnerability among body size 
or life-stage (Gale 2005, pp. 30-47; Post et al. 2006, p. 975; Carlson 
and Rahel 2007 pp. 1340-1341). Studies of other salmonid species in a 
river basin in southwestern Wyoming determined that ditches typically 
entrain a small proportion (less than 4 percent) of the total estimated 
trout in the basin (Carlson and Rahel 2007, p. 1335) and that this 
represented a very small percentage of the total mortality for those 
populations (Post et al. 2006, pp. 875, 884; Carlson and Rahel 2007, 
pp. 1335, 1339). Whether or not this amount of mortality can cause 
population instability is unclear (Post et al. 2006, p. 886; Carlson 
and Rahel 2007, pp. 1340-1341). However, in some cases, even small 
vital rate changes in a trout population can theoretically cause 
population declines (Hilderbrand 2003, pp. 260-261).
    The overall magnitude and population-level effect of entrainment on 
Arctic grayling in the Big Hole River

[[Page 54729]]

is unknown but possibly significant given the large number of 
unscreened surface-water diversions in the system and the large volumes 
of water diverted for irrigation. Given the low abundance of the 
species, even a small amount of entrainment may be biologically 
significant and is unlikely to be offset by compensatory effects (i.e., 
higher survival in Arctic grayling that are not entrained).
    Entrainment also may be a problem for Arctic grayling at some 
locations within the Red Rock Lakes system (Unthank 1989, p. 10; Gillin 
2001, pp. 2-4, 3-18, 3-25), particularly outside of the Red Rock Lakes 
NWR (Boltz 2010, pers. comm.).
    Entrainment has been a past threat to Arctic grayling in the Big 
Hole River and the Red Rock Lakes system. It remains a current threat 
as most, if not all, irrigation diversions located in occupied habitat 
do not have any devices to exclude fish (i.e., fish screens). 
Entrainment will remain a threat in the foreseeable future unless 
diversion structures are modified to exclude fish. The Big Hole 
Grayling CCAA has provisions to reduce entrainment at diversions 
operated by enrolled landowners (MFWP et al. 2006, pp. 50-52). Non-
Federal landowners enrolled in the CCAA control approximately 50 to 70 
percent of the points of irrigation diversion in the upper Big Hole 
River (Roberts and Lamothe 2010, pers. comm.), so the threat of 
entrainment in the Big Hole River should be significantly reduced in 
the foreseeable future. We consider the foreseeable future to represent 
approximately 20 years based on the duration of the Big Hole Grayling 
CCAA. Under the auspices of the Red Rock Lakes NWR CCP, a fish screen 
is planned to be installed on at least one diversion on the Red Rock 
Creek (USFWS 2009, p. 72), which is the primary spawning tributary for 
Arctic grayling in the Red Rock Lakes system. Overall, we anticipate it 
may take years to design and install fish screens on all the diversions 
that can entrain grayling in the Big Hole River and Red Rock Lakes 
systems; thus we conclude that entrainment remains a current threat 
that will continue to exist, but will decline in magnitude during the 
foreseeable future (next 10 to 20 years) because of implementation of 
the CCAA and CCP.

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). These riparian zones are important for Arctic grayling because 
of their effect on water quality and role in creating and maintaining 
physical habitat features (pools) used by the species.
    Removal of willows and riparian clearing concurrent with livestock 
and water management along the Big Hole River has apparently 
accelerated in recent decades, and, in conjunction with streamside 
cattle grazing, has led to localized bank erosion, channel instability, 
and channel widening (Confluence Consulting et al. 2003, pp. 24-26; 
Petersen and Lamothe 2006, pp. 16-17; Bureau of Land Management (BLM) 
2009a, pp. 14-21). Arctic grayling abundance in the upper Big Hole 
River is positively related to the presence of overhanging vegetation, 
primarily willows, which are associated with pool habitat (Lamothe and 
Magee 2004b, pp. 21-22). Degradation of riparian habitat in the upper 
Big Hole River has led to a shift in channel form (from multiple 
threads to a single wide channel), increased erosion rates, reduced 
cover, increased water temperatures, and reduced recruitment of large 
wood into the active stream channel (Confluence Consulting et al. 2003, 
pp. 24-26). All of these combine to reduce the suitability of the 
habitat for species like Arctic grayling, and likely reduce grayling 
growth, survival, and reproduction.
    Livestock grazing both within the Red Rock Lakes NWR and on 
adjacent private lands has 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, that are preferred habitats for adult Arctic grayling 
(Lamothe and Magee 2004b, pp. 21-22; Hughes 1992, entire). Loss of 
pools likely reduces growth and survival of adult grayling. Loss of 
riparian vegetation increases bank erosion, which can lead to siltation 
of spawning gravels, which may in turn harm grayling by reducing the 
extent of suitable spawning habitat and reducing survival of Arctic 
grayling embryos already present in the stream gravels. The condition 
of riparian habitats upstream from the Upper and Lower Red Rock Lakes 
may have improved during the 1990s (Mogen 1996, p. 77), and ongoing 
efforts to improve grazing management and restore riparian habitats are 
ongoing both inside the Red Rock Lakes NWR (USFWS 2009, pp. 67, 75) and 
upstream (AGW 2010, p. 7; Korb 2010, pers. comm.). However, the 
existing condition of riparian habitats continues to constitute a 
threat to Arctic grayling because the loss of pool habitat and the 
deposition of fine sediments may take some time to be reversed after 
the recovery of riparian vegetation.
    Much of the degradation of riparian habitats in the Big Hole River 
and Red Rock Lakes systems has occurred within the past 50 to 100 
years, but the influence of these past actions continues to affect the 
structure and function of aquatic habitats in these systems. Thus, 
while the actual loss of riparian vegetation has presumably slowed 
during the past 10 years, the effect of reduced riparian vegetation 
continues to promote channel widening and sedimentation, and limits the 
creation and maintenance of pool habitats. Thus, degradation of 
riparian habitats is a current threat. Degradation of riparian habitats 
will remain a threat in the foreseeable future until riparian 
vegetation recovers naturally or through direct restoration, which may 
occur during the next 20 years in the Big Hole River and portions of 
the Red Rock Lakes system. Protection and direct restoration of 
riparian habitats in the Big Hole River is occurring on a fairly large 
scale under the provisions of the Big Hole Grayling CCAA (Lamothe et 
al. 2007, pp. 13-26; Everett 2010, pp. 10-23), which should 
substantially reduce threats from riparian habitat degradation on 
private lands. Protection and restoration of riparian habitats 
implemented under the Red Rock Lakes NWR's CCP (see discussion under 
Factor D, below) should reduce threats from riparian habitat 
degradation within the NWR's boundary, but similar actions need to be 
taken on private lands adjacent to it (AGW 2010, p. 7; Korb 2010, pers. 
comm.) to appreciably reduce these threats in the foreseeable future 
and to expand the distribution of the species into formerly occupied 
habitat within that drainage.

Sedimentation

    Sedimentation has been proposed as a mechanism behind the decline 
of Arctic grayling and its habitat in the Red Rock Lakes (Unthank 1989, 
p. 10; Mogen 1996, p. 76). Livestock grazing upstream has led to 
accelerated sediment transport in tributary streams, and deposition of 
silt in both stream and lakes has likely led to loss of fish habitat by 
filling in pools, covering spawning gravels, and reducing water depth 
in Odell and Red Rock Creeks, where Arctic grayling are still believed 
to spawn (MFWP 1981, p. 105; Mogen 1996, pp. 73-76).
    Sedimentation in the Upper and Lower Red Rock Lakes is believed to

[[Page 54730]]

affect Arctic grayling by, in winter, reducing habitat volume (e.g., 
lakes freezing to the bottom) and promoting hypoxia (low oxygen), which 
generally concentrates fish in specific locations which have suitable 
depth, and thus increases the probability of competition and predation, 
and, in summer, causing thermal loading stress (see Dewatering From 
Irrigation and Consequent Increased Water Temperatures discussion, 
above). Depths in the Red Rock Lakes have decreased significantly, with 
a decline in maximum depth from 7.6 to 5.0 m (25 to 16.4 ft) to less 
than 2 m (6.5 ft) noted in Upper Red Rock Lake over the past century 
(Mogen 1996, p. 76). Lower Red Rock Lake has a maximum depth of 
approximately 0.5 m (1.6 ft), and freezes within a few inches of the 
bottom or freezes solid (Unthank 1989, p. 10). Consequently, the Lower 
Red Rock Lake does not appear to provide suitable overwintering habitat 
for adfluvial Arctic grayling and may be devoid of grayling except for 
the few individuals that may migrate between Odell Creek and Upper Red 
Rock Lake (Mogen, 1996, p. 47).
    Dissolved oxygen levels in Upper Red Rock Lake during winter 1994-
1995 dropped as low as 0.5 to 0.15 parts per million (ppm; Gangloff 
1996, pp. 41-42, 72), well below the critical minimum of 1.3 to 1.7 ppm 
measured for adult Arctic grayling acclimated to water temperatures 
less than or equal to 8 [deg]C (46 [deg]F) (Feldmeth and Eriksen 1978, 
pp. 2042-2043). Thus, lethally low oxygen levels can occur during 
winter in Upper Red Rock Lake, the primary overwintering area for 
adfluvial Arctic grayling in the system. Winter kill of invertebrates 
and fishes (e.g., suckers Catostomus spp.) has been recorded in Upper 
Red Rock Lake (Gangloff 1996, pp. 39-40). Gangloff (1996, pp. 71, 79) 
hypothesized that Arctic grayling in Upper Red Rock Lake exhibit 
behavioral mechanisms or physiological adaptations that permit them to 
survive otherwise lethally low oxygen levels. Oxygen conditions in the 
lake during winter are related to the effect of snowpack and ice cover 
on light penetration and the density of macrophytes (rooted aquatic 
plants) during the preceding growing season (Gangloff 1996, pp. 72-74). 
Arctic grayling under winter ice seek areas of higher oxygen 
concentration (oxygen refugia) within the lake or near inlet streams of 
Upper Red Rock Lake (Gangloff 1996, pp. 78-79). Consequently, we expect 
factors leading to reduced lake depth due to upstream erosion and 
sedimentation within the lake, or factors that promote eutrophication 
due to macrophyte growth, to lead to more frequent winter hypoxia (low 
dissolved oxygen concentrations detrimental to aquatic organsims) in 
Upper Red Rock Lake, which is the most important overwintering habitat 
for adfluvial Arctic grayling in the system.
    The effects of erosion and sedimentation on spawning gravels and 
reduction of habitat volume in Upper and Lower Red Rock Lakes are past 
and current threats. Improved land use may be reducing the rates of 
erosion in tributary streams (USFWS 2009, pp. 75-76; Korb 2010, pers. 
comm.). However, sedimentation of the lakes will likely remain a threat 
(because of reduced overwintering habitat, and high water temperatures 
in summer) in the foreseeable future unless some event mobilizes these 
sediments and transports them out of the lakes.
    Protection and restoration of riparian habitats implemented under 
the Red Rock Lakes NWR's CCP (see discussion under Factor D, below) 
should reduce the magnitude of sedimentation within the NWR's 
boundaries, but similar actions need to be taken on private lands 
adjacent to it (AGW 2010, p. 7; Korb 2010, pers. comm.) to appreciably 
reduce threats in the foreseeable future.

Summary of Factor A

    Based on the best available information, we find that the 
historical range of the Missouri River DPS of Arctic grayling has been 
greatly reduced, and the remaining native populations continue to face 
significant threats to their habitat. Large-scale habitat fragmentation 
by dams was likely a significant historical factor causing the range-
wide decline of the DPS. The most significant current threats to the 
DPS are from land and water use activities that have affected the 
structure and function of aquatic systems, namely stream dewatering 
from irrigation withdrawals, which reduces habitat volume and increases 
summer water temperatures; potential loss of individuals in irrigation 
ditches (entrainment); degraded riparian habitats promoting erosion, 
sedimentation, increased water temperatures, and loss of pool habitat; 
and migration barriers that restrict movement to and from spawning, 
feeding, and sheltering habitats. These are among the significant 
current threats to Arctic grayling populations in the Big Hole River, 
Madison River-Ennis Reservoir, and Red Rock Lakes system. The habitat-
related threats to the Big Hole River population should be reduced in 
the foreseeable future by implementation of the Big Hole Grayling CCAA, 
a formalized conservation plan with 32 private landowners currently 
enrolled. The Big Hole Grayling CCAA is expected to reduce threats from 
dewatering, high water temperatures, barriers to fish passage, and 
entrainment in irrigation ditches that are associated with land and 
water use in the upper Big Hole River watershed during the foreseeable 
future (next 20 years based on the duration of the CCAA). Non-Federal 
landowners enrolled in the Big Hole Grayling CCAA control or own 
approximately 50 to 70 percent of the points of irrigation diversion in 
the upper Big Hole River, so these landowners should have the ability 
to reduce habitat-related threats to Arctic grayling in the Big Hole 
River by a corresponding amount. However, the present or threatened 
destruction, modification, or curtailment of habitat remains a threat 
to the DPS overall. This factor is expected to continue to be a threat 
to the species in the foreseeable future because it is not 
comprehensively addressed for other populations, especially those in 
the Madison River and Red Rock Lakes systems where ongoing habitat-
related threats (described above) may be making unoccupied habitat 
unsuitable for Arctic grayling, and may thus limit the recovery 
potential of the DPS.

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

    Arctic grayling of the upper Missouri River are handled for 
recreational angling; and for scientific, population monitoring, and 
restoration purposes.

Recreational Angling

    Arctic grayling are highly susceptible to capture by angling (ASRD 
2005, pp. 19-20), and intense angling pressure can reduce densities and 
influence the demography of exploited populations (Northcote 1995, pp. 
171-172). Overfishing likely contributed to the rangewide decline of 
the DPS in the upper Missouri River system (Vincent 1962, pp. 49-52, 
55; Kaya 1992, pp. 54-55). In 1994, concern over the effects of angling 
on fluvial Arctic grayling led the State of Montana to implement catch-
and-release regulations for Arctic grayling captured in streams and 
rivers within its native range, and those regulations remain in effect 
(MFWP 2010, p. 52). Catch-and-release regulations for Arctic grayling 
in the Big Hole River have been in effect since 1988 (Byorth 1993, p. 
8). Catch-and-release regulations also are in effect for Ennis 
Reservoir on the Madison River (MFWP 2010, p. 61). Angling is not

[[Page 54731]]

permitted in either of the Red Rock Lakes to protect breeding waterfowl 
and trumpeter swans (Cygnus buccinator) (USFWS 2009, p. 147), and 
catch-and-release regulations remain in effect for any Arctic grayling 
captured in streams (e.g., Odell Creek or Red Rock Creek) in the Red 
Rock Lakes system (MFWP 2010, p. 56).
    In Miner and Mussigbrod Lakes, anglers can keep up to 5 Arctic 
grayling per day and have up to 10 in possession, in accordance with 
standard daily and possession limits for that angling management 
district (MFWP 2010, p. 52). The current abundance of Arctic grayling 
in Mussigbrod Lake (see Table 4 above) suggests that present angling 
exploitation rates are not a threat to that population. Miner Lakes 
grayling are less abundant compared to Mussigbrod Lake, but we are not 
sure whether angling exploitation constitutes a threat to Miner Lakes 
grayling.
    Repeated catch-and-release angling may harm individual fish, 
causing physiological stress and injury (i.e., hooking wounds). Catch-
and-release angling also can result in mortality at a rate dependent on 
hooking location, hooking duration, fish size, water quality, and water 
temperature (Faragher et al. 2004, entire; Bartholomew and Bohnsack 
2005, p. 140). Repeated hooking (up to five times) of Arctic grayling 
in Alaska did not result in significant additional mortality (rates 0 
to 1.4 percent; Clark 1991, pp. 1, 25-26). In Michigan, hooking 
mortality of Arctic grayling in lakes averaged 1.7 percent per capture 
event based on 355 individuals captured with artificial flies and lures 
(Nuhfer 1992, pp. 11, 29). Higher mortality rates (5 percent) have been 
reported for Arctic grayling populations in the Great Slave Lake area, 
Canada (Falk and Gillman 1975, cited in Casselman 2005, p. 23). 
Comparatively high catch rates for Arctic grayling have been observed 
in the Big Hole River, Montana (Byorth 1993, pp. 26-27, 36), and 
average hooking wound rates ranged from 15 to 30 percent among study 
sections (Byorth 1993, p. 28). However, overall hooking mortality from 
single capture events was low (1.4 percent), which led Byorth to 
conclude that the Big Hole River population was not limited by angling 
(Byorth 1994b, entire).
    Compared to the average catch-and-release mortality rates of 4.2 to 
4.5 percent in salmonids as reported by Schill and Scarpella (1997, p. 
873), and the mean and median catch-and-release mortality rates of 18 
percent and 11 percent from a meta-analysis of 274 studies (Bartholomew 
and Bohnsack 2005, pp. 136-137), the catch-and-release mortality rates 
for Arctic grayling are comparatively low (Clark 1991, pp. 1, 25-26; 
Nuhfer 1992, pp. 11, 29; Byorth 1994b, entire). We are uncertain 
whether these lower observed rates reflect an innate resistance to 
effects of catch-and-release angling in Arctic grayling or whether they 
reflect differences among particular populations or study designs used 
to estimate mortality. Even if catch-and-release angling mortality is 
low (e.g., 1.4 percent as reported in Byorth 1994b, entire), the high 
catchability of Arctic grayling (ASRD 2005, pp. 19-20) raises some 
concern about the cumulative mortality of repeated catch-and-release 
captures. For example, based on the Arctic grayling catch rates and 
angler pressure reported by Byorth (1993, pp. 25-26) and the population 
estimate for the Big Hole River reported in Byorth (1994a, p. ii), a 
simple calculation suggests that age 1 and older grayling susceptible 
to recreational angling may be captured and released 3 to 6 times per 
year.
    The MFWP closes recreational angling in specific reaches of the Big 
Hole River when environmental conditions are considered stressful. 
Specific streamflow and temperature thresholds initiate mandatory 
closure of the fishery (Big Hole Watershed Committee 1997, entire). 
Such closures have been implemented in recent years. For example, the 
upper segment of the Big Hole River between Rock Creek Road to the 
confluence of the North Fork Big Hole River has been closed to angling 
at various times during 2004 (Magee et al. 2005, p. 7), 2005 (Magee et 
al. 2006, p. 20), and 2006 (Rens and Magee 2007, p. 8).
    In conclusion, angling harvest may have significantly reduced the 
abundance and distribution of the upper Missouri River DPS of Arctic 
grayling during the past 50 to 100 years, but current catch-and-release 
fishing regulations (or angling closures) in most waters occupied by 
extant populations have likely ameliorated the past threat of 
overharvest. Although we have some concerns about the potential for 
cumulative mortality caused by repeated catch-and-release of individual 
Arctic grayling in the Big Hole River, we have no strong evidence 
indicating that repeated capture of Arctic grayling under catch-and-
release regulations is currently limiting that population or the DPS. 
Moreover, fishing is restricted in the Big Hole River, an important 
recreational fishing destination in southwestern Montana, when 
streamflow and temperature conditions are likely to increase stress to 
captured grayling. Anglers can still capture and keep Arctic grayling 
in Miner and Mussigbrod Lakes in accordance with State fishing 
regulations, but we have no evidence that current levels of angling are 
affecting these populations. We thus have no evidence that recreational 
angling represents a current threat to the DPS. If we assume that 
future fishing regulations would be at least as conservative as current 
regulations, and that the current levels of angling pressure will 
continue, then recreational angling does not represent a threat in the 
foreseeable future.

Monitoring and Scientific Study

    The MFWP consistently monitors the Arctic grayling population in 
the Big Hole River and its tributaries, and to a lesser extent those 
populations in the Madison River and Red Rock Lakes system (Rens and 
Magee 20007, entire). Electrofishing (use of electrical current to 
temporarily and non-lethally immobilize a fish for capture) is a 
primary sampling method to monitor Arctic grayling in the Big Hole 
River, Madison River, and Red Rock Lakes (Rens and Magee 2007, pp. 13, 
17, 20). A number of studies have investigated the effects of 
electrofishing on various life stages of Arctic grayling. Dwyer and 
White (1997, p. 174) found that electrofishing reduced the growth of 
juvenile Arctic grayling and concluded that long-term, sublethal 
effects of electrofishing were possible. Hughes (1998, pp. 1072, 1074-
1075) found evidence that electrofishing and tagging affected the 
growth rate and movement behavior of Arctic grayling in the Chena 
River, Alaska. Roach (1999, p. 923) studied the effects of 
electrofishing on fertilized Arctic grayling eggs and found that while 
electrofishing could result in egg mortality, the population-level 
effects of such mortality were not likely to be significant. Lamothe 
and Magee (2003, pp. 16, 18-19) noted mortality of Arctic grayling in 
the Big Hole River during a radio-telemetry study, and concluded that 
handling stress or predation were possible causes of mortality. 
Population monitoring activities in the Big Hole River are curtailed 
when environmental conditions become unsuitable (Big Hole Watershed 
Committee 1997, entire), and recent monitoring reports (Magee and 
Lamothe 2004, entire; Magee et al. 2005, entire; Rens and Magee 2007, 
entire) provide no evidence that electrofishing is harming the Arctic 
grayling population in the Big Hole River.
    A study in the Big Hole River is investigating the availability and 
use of coldwater thermal refugia for Arctic grayling and other resident 
fishes (Vatland and Gressewell 2009, entire).

[[Page 54732]]

 The study uses fish tagged with passive integrated transponder (PIT) 
tag technology to record movement past receiving antennas. The PIT tags 
are small (23 mm or less than 1 in. long) and implanted into the body 
cavity of the fish during a quick surgical procedure. During 2007-2008, 
a total of 81 Arctic grayling from the Big Hole River and its 
tributaries were implanted with these PIT tags (Vatland and Gressewell 
2009, p. 12). A short-term study on the potential effects of PIT tag 
implantation on Arctic grayling found 100 percent retention of tags and 
100 percent survival of tagged individuals during a 4-day trial 
(Montana State University 2008, p. 7). Based on the results of the 
controlled trials, we have no evidence to indicate that PIT tagging the 
wild Arctic grayling in the Big Hole River constitutes a significant 
threat to the population.
    Traps, electrofishing, and radio telemetry have been used to 
monitor and study Arctic graying in the Red Rock Lakes system (Gangloff 
1996, pp. 13-14; Mogen 1996, pp. 10-13, 15; Kaeding and Boltz 1999, p. 
4; Rens and Magee 2007, p. 17); however, there is no data to indicate 
these monitoring activities reduce the growth and survival of 
individual Arctic grayling or otherwise constitute a current or future 
threat to the population.
    The Arctic grayling population in the Madison River-Ennis Reservoir 
is not monitored as intensively as the Big Hole River population (Rens 
and Magee 2007, pp. 20-21). When electrofishing surveys targeting 
Arctic grayling in the Madison River do occur, they are conducted 
during the spawning run for that population (Clancey 1996, p. 6). 
Capture and handling during spawning migrations or during actual 
spawning could affect the reproductive success of individual Arctic 
grayling. However, under recent monitoring frequencies, any population-
level effect of these activities is likely negligible, and we have no 
data to indicate these monitoring activities reduce the growth and 
survival of individual Arctic grayling or otherwise constitute a 
current or future threat to the Madison River population.
    The Miner Lakes and Mussigbrod Lake populations of Arctic grayling 
are infrequently monitored (Olsen 2010, pers. comm.). Since monitoring 
of these populations has been minimal, we do not believe that 
monitoring or scientific study constitutes a current or foreseeable 
threat to these particular populations.
    The intensity of monitoring and scientific investigation varies 
among the different populations in the DPS, but we have no evidence 
suggesting that monitoring or scientific study has influenced the 
decline of Arctic grayling in the Missouri River basin. We also have no 
evidence indicating these activities constitute a current threat to the 
DPS that would result in measurable, population-level effects. We 
expect similar levels of population monitoring and scientific study in 
the future, and we have no basis to conclude that these activities 
represent a threat in the foreseeable future.

Reintroduction Efforts

    Attempts to restore or re-establish native populations of both 
fluvial and adfluvial Arctic grayling may result in the mortality of 
embryos and young fish. The MFWP attempted to restore fluvial Arctic 
graying to historic waters in the upper Missouri River using a 
combination of stocking and embryo incubating devices (remote site 
incubators) placed in target streams (Rens and Magee 2007, pp. 24-38). 
Currently, gametes (eggs and sperm) used to re-establish the fluvial 
ecotype come from captive brood reserves of Big Hole River grayling 
maintained in Axolotl and Green Hollow II Lakes (Rens and Magee 2007, 
pp. 22-24). Removal of gametes from the wild Big Hole River population 
was necessary to establish this brood reserve (Leary 1991, entire). The 
previous removal of gametes for conservation purposes may have reduced 
temporarily the abundance of the wild population if the population was 
unable to compensate for this effective mortality by increased survival 
of remaining individuals. However, the establishment of a brood reserve 
provides a conservation benefit from the standpoint that gametes from 
the reserve can be harvested to use for translocation efforts to 
benefit the species. Unfortunately, these translocations have not yet 
resulted in establishment of any fluvial populations. Ultimately, we do 
not have any data to indicate that past gamete collection from the Big 
Hole River population harmed the wild population. Consequently, we have 
no basis to conclude that gamete collection from the wild Big Hole 
River Arctic grayling population constitutes a current or future threat 
to the population.
    Efforts to re-establish native, genetically pure populations of 
adfluvial Arctic grayling in the Red Rock Lakes system and to maintain 
a brood reserve for that population have resulted in the direct 
collection of eggs from Arctic grayling spawning runs in Red Rock 
Creek. During 2000-2002, an estimated 315,000 Arctic grayling eggs were 
collected from females captured in Red Rock Creek (Boltz and Kaeding 
2002, pp. v, 8). The Service placed over 180,000 of these eggs in 
remote site incubators in streams within the Red Rock Lakes NWR that 
historically supported Arctic grayling spawning runs (Boltz and Kaeding 
2002, pp. v, 10). Despite preliminary observations of grayling spawning 
in historically occupied waters within the Red Rock Lakes NWR following 
the use of remote site incubators (Kaeding and Boltz 2004, pp. 1036), 
spawning runs at these locations have apparently not become established 
(Boltz 2006, pers. comm.). Attempts to establish a brood reserve of 
adfluvial Arctic grayling within the NWR's boundaries (MacDonald Pond) 
were not successful (Boltz and Kaeding 2002, pp. 21-22). Red Rock Lakes 
NWR plans to re-establish Arctic grayling in Elk Springs and Picnic 
Creeks and establish a brood stock in Widgeon Pond as part of its CCP 
(USFWS 2009, pp. 72, 75). The MFWP and the Service are currently 
collaborating on an effort to re-establish an Arctic grayling spawning 
run in Elk Springs Creek and to establish a genetically pure brood 
reserve of Red Rock Lakes grayling in Elk Lake as no such population 
exists for use in conservation and recovery (Jordan 2010, pers. comm.). 
These actions will require the collection of gametes (approximately 
360,000 eggs) from Arctic grayling captured in Red Rock Creek (Jordan 
2010, pers. comm.). Approximately 10 percent of these eggs will be 
returned to Red Rock Creek and incubated in that stream (using a remote 
site incubation method that results in high survivorship of embryos) 
(Kaeding and Boltz 2004, entire) to mitigate for collection of gametes 
from the wild spawning population (Jordan 2010, pers. comm.). We 
presume these ongoing actions may necessitate the collection of gametes 
from wild Arctic grayling in Red Rock Creek, so the potential effect of 
such collections on the extant wild population should be evaluated and 
mitigation for the use of these gametes (e.g., using remote site 
incubators at the collection source or another method) should continue.
    Overall, we have no evidence to indicate that collection of gametes 
from the wild populations in the Big Hole River and Red Rock Lakes 
systems have contributed to population-level declines in those 
populations, or that the previous collections represent 
overexploitation. Future plans to collect gametes from Arctic grayling 
in the Big Hole River and Red Rock Lakes should be carefully evaluated 
in light of the status of those populations at the anticipated time of 
the collections. We

[[Page 54733]]

encourage the agencies involved to coordinate their efforts and develop 
a strategy for broodstock development and recovery efforts that 
minimizes any potential impacts to wild native populations. However, at 
present, we do not have any data indicating collection of gametes for 
conservation purposes represents a current threat to the Big Hole River 
and Red Rock Lakes populations. We have no evidence to indicate that 
gamete collection will increase in the future, so we have no basis to 
conclude that this represents a threat in the foreseeable future.

Summary of Factor B

    Based on the information available at this time, we conclude that 
overexploitation by angling may have contributed to the historical 
decline of the upper Missouri River DPS of Arctic grayling, but we have 
no evidence to indicate that current levels of recreational angling, 
population monitoring, scientific study, or conservation actions 
constitute overexploitation; therefore, we do not consider them a 
threat. We expect similar levels of these activities to continue in the 
future, and we do not believe they represent a threat in the 
foreseeable future.

C. Disease or Predation

Disease

    Arctic grayling are resistant to whirling disease, which is 
responsible for population-level declines of other stream salmonids 
(Hedrick et al. 1999, pp. 330, 333). However, Arctic grayling are 
susceptible to bacterial kidney disease (BKD). Some wild populations in 
pristine habitats test positive for BKD (Meyers et al. 1993, pp. 186-
187), but clinical effects of the disease are more likely to be evident 
in captive populations (Meyers et al. 1993, entire; Peterson 1997, 
entire). To preclude transmission of BKD between grayling during brood 
reserve, hatchery, and wild grayling translocation efforts, MFWP tests 
kidney tissue and ovarian fluid for the causative agent for BKD as well 
as other pathogens in brood populations (Rens and Magee 2007, pp. 22-
24).
    Information on the prevalence of the BKD or other diseases in 
native Arctic grayling populations in Montana is generally lacking. One 
reason is that some disease assays are invasive or require the 
sacrifice of individual fish (e.g., removal of kidney tissue to test 
for BKD pathogen.) Therefore, such testing is typically avoided in 
native populations of Missouri River Arctic grayling that are low in 
abundance. Arctic grayling in captive brood reserves (e.g., Axolotl 
Lake, Green Hollow Lake) and introduced populations (e.g., Sunnyslope 
Canal, Rogers Lake) have all tested negative for infectious 
hematopoietic necrosis virus (IHNV), infectious pancreatic necrosis 
virus (IPNV), Myxobolus cerebralis (the pathogen that causes whirling 
disease), Renibacterium salmoninarum (the pathogen that causes BKD), 
and Aeromonas salmonicida (the pathogen that causes furunculosis) 
(USFWS 2010a). Consequently, we have no evidence at this time that 
disease threatens native Arctic grayling of the upper Missouri River. 
We have no basis to conclude that disease will become a future threat, 
so we conclude that disease does not constitute a threat in the 
foreseeable future.

Predation By and Competition With Nonnative Trout

    Brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), 
and rainbow trout have been introduced across the United States to 
provide recreational fishing opportunities, and are now widely 
distributed and abundant in the western United States, including the 
upper Missouri River system (Schade and Bonar 2005, p. 1386). One or 
more of these nonnative trout species co-occur with every native Arctic 
grayling population in the basin. Ecological interactions (predation 
and competition) with the brook trout, brown trout, and rainbow trout 
are among the long-standing hypotheses to explain decline of Arctic 
grayling in the upper Missouri River system and the extirpation of 
populations from specific waters (Nelson 1954, p. 327; Vincent 1962, 
pp. 81-96; Kaya 1992, pp. 55-56).
    The potential for interspecific interactions should be greatest 
among species with similar life histories and ecologies that did not 
co-evolve (Fausch and White 1986, p. 364). Arctic grayling in the 
Missouri River basin have similar ecologies to brook trout, rainbow 
trout, and brown trout, yet they do not share a recent evolutionary 
history. The evidence for predation and competition by nonnative trout 
on Arctic grayling in the upper Missouri River basin is largely 
circumstantial, and inferred from the reduced abundance and 
distribution of Arctic grayling following encroachment by nonnative 
trout (Kaya 1990, pp. 52-54; Kaya 1992, p. 56; Magee and Byorth 1995, 
p. 54), as well as the difficulty in establishing Arctic grayling 
populations in waters already occupied by nonnative trout, especially 
brown trout (Kaya 2000, pp. 14-15). Presumably, competition with 
ecologically-similar species for food, shelter, and spawning locations 
can lead to reduced growth, reproduction, and survival of Arctic 
grayling (i.e., where they are outcompeted by nonnative trout). The 
strength of competition is very difficult to measure in wild trout 
populations (Fausch 1988, pp. 2238, 2243; 1998, pp. 220, 227). Few 
studies have evaluated competition between Arctic grayling and these 
nonnative species. Brook trout do not appear to negatively affect 
habitat use or growth of juvenile, hatchery-reared Arctic grayling 
(Byorth and Magee 1998, p. 921), but further studies are necessary to 
determine whether competition or predation occur at other life stages 
or with brown or rainbow trout (Byorth and Magee 1998, p. 929).
    Predation represents direct mortality that can limit populations, 
and YOY Arctic grayling may be particularly susceptible to predation by 
other fishes because they are smaller and weaker swimmers than trout 
fry (Kaya 1990, pp. 52-53).
    The incidence of competition and predation between nonnative trout 
and Arctic grayling likely depends on environmental context (e.g., 
habitat type and quality, environmental conditions such as temperature, 
and so forth). Nonetheless, it is widely accepted that biotic 
interactions with nonnative species are to some extent responsible for 
the decline of many native fishes in the western United States (Dunham 
et al. 2002, pp. 373-374 and references therein; Fausch et al. 2006, 
pp. 9-11 and references therein).
    In the Big Hole River, brook trout, rainbow trout, and brown trout 
have been established for some time (Kaya 1992, pp. 50-51) and are much 
more abundant than Arctic grayling (Rens and Magee 2007, p. 42). In 
general, brook trout is the most abundant nonnative trout species in 
the Big Hole River upstream from Wisdom, Montana (Rens and Magee 2007, 
pp. 7, 42; Lamothe et al. 2007, pp. 35-38), whereas rainbow trout and 
brown trout are comparatively more abundant in the reaches immediately 
above and downstream from the Divide Dam (Kaya 1992, p. 56; Oswald 
2005b, pp. 22-29; Lamothe et al. 2007, pp. 35-38; Rens and Magee 2007, 
p. 10). Rainbow trout are apparently more abundant than brown trout 
above the Divide Dam (Olsen 2010, pers. comm.), but brown trout are 
more abundant than rainbow trout below the dam (Oswald 2005b, pp. 22-
33). Recent observations of increased brown trout abundance and 
distribution in the upper Big Hole River indicate that the species may 
be encroaching further upstream (AGW 2008, p. 1). Overall, at least one 
nonnative species occurs in the

[[Page 54734]]

mainstem Big Hole River and tributary locations where Arctic grayling 
are present (Lamothe et al. 2007, p. 37; Rens and Magee 2007, p. 42). 
The Big Hole Grayling CCAA recognizes that the potential for 
competition with and predation by nonnative trout may limit the 
effectiveness of its conservation actions (MFWP et al. 2006, pp. 54-
55).
    The MFWP is the lead agency implementing the Big Hole Grayling CCAA 
under an agreement with the Service, and MFWP establishes fishing 
regulations for most waters in Montana. Different regulations may apply 
on NWR lands administered by the Service. The MFWP has agreed to 
continue catch-and-release regulations for Arctic grayling in the Big 
Hole River, to increase daily possession limits for nonnative brook 
trout (MFWP et al. 2006, p. 55; MFWP 2010, p. 52), and to consider 
whether additional management actions are necessary to address threats 
from nonnative trout based on recommendations of a technical committee 
of the AGW (MFWP et al. 2006, p. 55). However, we are not aware of data 
that shows angling regulations currently, or are expected to, reduce 
threats from brook trout. We also are not aware of any evaluations 
provided by the technical committee or of any additional management 
actions taken by MFWP to address potential threats from nonnative 
trout. Nonnative trout are widely distributed and abundant in the Big 
Hole River, and eradication may be impossible. The Big Hole Grayling 
CCAA focuses primarily on habitat-related threats (not nonnative 
trout), so we presume that nonnative trout will remain a threat to 
Arctic grayling for the foreseeable future.
    Arctic grayling in Miner and Mussigbrod Lakes co-occur with one or 
more species of nonnative trout, but we have no quantitative 
information on the relative abundance of the introduced species. Brook 
trout and rainbow trout are both characterized as ``common'' in lower 
Miner Lakes (MFISH 2010), and brook trout in Mussigbrod Lake are 
similarly categorized as ``common'' (MFISH 2010). Brook trout have been 
present in the Big Hole River for at least 60 years (Liknes 1981, p. 
34). The date when brook trout were introduced into Miner and Mussibrod 
Lakes is unknown (Liknes 1981, p. 33), but the co-occurrence of the 
brook trout with Arctic grayling in these habitats suggests that 
displacement of Arctic grayling by brook trout is not inevitable.
    In the Madison River in and near Ennis Reservoir, brown trout and 
rainbow trout are abundant and are the foundation of an important 
recreational fishery (e.g., Byorth and Shepard 1990, p. 1). Nonnative 
rainbow trout and brown trout substantially outnumber Arctic grayling 
in the Madison River near Ennis Reservoir (Clancey and Lohrenz 2005, 
pp. 26, 29-31; 2009, pp. 91, 93).
    In the Red Rock Lakes system, brook trout and hybrid cutthroat 
trout (Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) 
rainbow trout; Mogen 1996, p. 42) have well-established populations and 
dominate the abundance and biomass of the salmonid community (Katzman 
1998, pp. 2-3; Boltz 2010, pp. 2-3). Competition and predation risk for 
the Arctic grayling may be particularly acute in the shallow Upper Red 
Rock Lake when all fish species are forced to congregate in a few 
discrete deeper sites in response to environmental conditions, such as 
ice formation in winter (Boltz 2010, pers. comm.). Removal of nonnative 
trout from certain waters on the Red Rock Lakes NWR is part of the CCP 
(USFWS 2009, pp. 72, 75), so the frequency of predation of and 
competition with Arctic grayling by these species may be reduced at a 
limited spatial scale during the 15-year timeframe of the CCP.
    Studies attempting to specifically measure the strength of 
competition with and magnitude of predation by nonnative trout on 
Arctic grayling in Montana have yielded mixed results. Only one study 
attempted to measure competition between brook trout and Arctic 
grayling (Byorth and Magee 1998, entire), and their study did not find 
strong evidence for presumed effects of competition, such as 
differences in microhabitat use or growth rate (Byorth and Magee 1998, 
p. 1998). However, the authors cautioned that further studies were 
needed to determine whether or not competition may be occurring between 
fish of different sizes or ages (other than those tested) or whether 
competition with or predation by rainbow trout or brown trout is 
occurring (Byorth and Magee, 1998, p. 929). Measuring the strength of 
competition and determining the relevant mechanisms (e.g., competition 
for food vs. space) is difficult to measure in fish populations (Fausch 
1998, pp. 220, 227), so the lack of definitive evidence for the 
mechanisms of competition may simply be due to the inherent 
difficulties in measuring these effects and determining their influence 
on the population. Similarly, predation by brook trout on Arctic 
grayling eggs and fry has been observed in both the Big Hole River and 
Red Rock Lakes systems (Nelson 1954, entire; Streu 1990, p. 17; Katzman 
1998, pp. 35, 47, 114), but such observations have not been 
definitively linked with a population decline of Arctic grayling. To 
our knowledge, no studies have investigated or attempted to measure 
predation by brown trout or rainbow trout on Arctic grayling in 
Montana.
    Experimental evidence notwithstanding, the decline of Arctic 
grayling concurrent with encroachment by nonnative trout, combined with 
the difficulty in establishing grayling populations where nonnatives 
trout are present (Kaya 1992, pp. 55-56, 61; Kaya 2000, pp. 14-16), 
provides strong circumstantial evidence that a combination of predation 
and competition by nonnative trout has negatively affected Arctic 
grayling populations in the upper Missouri River. The lack of direct 
evidence for competition (e.g., with brook trout) or predation (e.g., 
by brown trout) most likely indicates that these mechanisms can be 
difficult to detect and measure in wild populations and that additional 
scientific investigation is needed. We recognize that displacement of 
Arctic grayling is not a certain outcome where the species comes into 
contact with brook trout (e.g., Big Hole River), but the circumstances 
that facilitate long-term co-existence vs. transitory co-existence are 
unknown. Ultimately, circumstantial evidence from Montana and the 
western United States suggests that the presence of nonnative trout 
species represents a substantial threat to native fishes including 
Arctic grayling. At least one species of nonnative trout is present in 
all waters occupied by native Arctic grayling populations in the upper 
Missouri River, so the threat is widespread and imminent, and we expect 
that nonnative trout will remain a part of the biological community. 
Thus, we expect that nonnative trout are a threat to Missouri River 
Arctic grayling in the foreseeable future.

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 halaietus) 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 (Ceryl alcyon),

[[Page 54735]]

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 grayling. The aforementioned 
mammals and birds can be effective fish predators, but 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 
substantial threat to Missouri River Arctic grayling in the foreseeable 
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 Missouri 
River DPS of Arctic grayling. We have no factual basis for concluding 
that disease may become a future threat, but anticipate that the 
likelihood of disease in native populations will depend on and interact 
with other factors (e.g., habitat condition, climate change) that may 
cumulatively stress individual fish and reduce their ability to 
withstand infection by disease-causing pathogens.
    Circumstantial evidence indicates that ecological interactions with 
nonnative trout species have led to the displacement of Arctic grayling 
from portions of its historic range in the upper Missouri River basin. 
Nonnative trout species, such as brook trout, brown trout, and rainbow 
trout, remain widely distributed and abundant in habitats currently 
occupied by native Arctic grayling populations. Consequently, we 
determined that the presence of nonnative trout represents a 
substantial current and foreseeable threat to native Arctic grayling of 
the upper Missouri River.
    Little is known about the effect of predation on Arctic grayling by 
birds and mammals. Such predation likely does occur, but in contrast to 
the pattern of displacement observed concurrent with encroachment by 
nonnative trout, 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 foreseeable threat to native Arctic grayling in the 
upper Missouri River.

D. Inadequacy of Existing Regulatory Mechanisms

    The ESA requires us to examine the adequacy of existing regulatory 
mechanisms with respect to those extant threats that place the species 
in danger of becoming either endangered or threatened. Thus, the scope 
of this analysis generally focuses on the extant native populations of 
Arctic grayling and potential current and foreseeable threats based on 
the inadequacy of existing regulatory mechanisms.

Federal Laws and Regulations

    Native Arctic grayling are present in or adjacent to land managed 
by the U.S. Forest Service (USFS) (Big Hole River, Miner, and 
Mussigbrod Lakes: Beaverhead-Deerlodge National Forest), National Park 
Service (NPS) (Big Hole River: Big Hole National Battlefield), Bureau 
of Land Management (BLM) (Big Hole River: Dillon Resource Area), USFWS 
(Red Rock Lakes NWR); and the Federal Energy Regulatory Commission 
(Madison River-Ennis Reservoir: Ennis Dam, operated under Project 2188 
license).
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 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 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.
Federal Land Policy and Management Act
    The BLM's 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.
    The BLM considers the fluvial Arctic grayling a sensitive species 
requiring special management consideration for planning and 
environmental analysis (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 Red Rock 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.
National Forest Management Act
    Under the USFS' National Forest Management Act (NFMA) of 1976, as 
amended (16 U.S.C. 1600-1614), the USFS shall strive 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 Northern Rocky 
Mountain Region (R1) considers fluvial Arctic grayling a sensitive 
species (USFS 2004, entire) for which population viability is a 
concern, as evidenced by a significant downward trend in population or 
a

[[Page 54736]]

significant downward trend in habitat capacity.
    Much of the headwaters of the Big Hole River drainage are within 
the boundary of the Beaverhead-Deerlodge National Forest. The Miner and 
Mussigbrod Lakes Arctic grayling populations are entirely within Forest 
boundaries. The Beaverhead-Deerlodge National Forest is currently 
revising its forest plan. The USFS does not propose to designate key 
fish watersheds solely to benefit grayling, but fluvial Arctic grayling 
will remain a sensitive species with Forest-wide standards and 
objectives to meet the species' habitat requirements (USFS 2009a, p. 
19). With respect to fluvial Arctic grayling, the USFS is proposing a 
Controlled Surface Use (CSU) stipulation in the Ruby River (an ongoing 
reintroduction site) and certain tributaries of the Big Hole River 
(USFS 2009b, pp. 29, B-13) to avoid impacts from mineral, gas, and oil 
extraction (USFS 2009b, pp. 27-28). These CSU stipulations define the 
minimum extent of buffer areas adjacent to streams. In general, the 
preferred forest plan alternative (Alternative 6, USFS 2009a, p. 6) is 
deemed by the USFS to provide management direction designed to ensure 
the persistence of grayling populations Forest-wide, and to meet 
viability requirements of this species (USFS 2009a, p. 146). The forest 
plan revision has not yet been finalized through a record of decision 
(ROD), so we are unable to specifically evaluate its potential effect 
on native Arctic grayling populations.
National Park Service 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.'' Native populations of Arctic 
grayling have been extirpated from Yellowstone National Park, but the 
Big Hole National Battlefield is adjacent to the North Fork of the Big 
Hole River (NPS 2006, entire), and Arctic grayling are occasionally 
encountered downstream from the Battlefield (Rens and Magee 2007, pp. 
7, 13). Consequently, a very small amount of currently occupied 
grayling habitat is in the vicinity of lands managed by the NPS; 
therefore, the NPS Organic Act is not thought to have any significant 
effect on native Arctic grayling populations.
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). Red 
Rocks NWR is 2,033-2,865 m (6,670-9,400 ft) above sea level, comprises 
48,955 ac, and lies east of the Continental Divide near the uppermost 
reach of the Missouri drainage (USFWS 2009, pp. v, 2). The Red Rocks 
NWR encompasses Lower and Upper Red Rock Lakes, which contain native 
grayling. The Red Rocks NWR CCP outlines a set of broad goals and 
specific objectives or strategies with respect to conservation of 
Arctic grayling that focuses on habitat improvements, reestablishment 
of populations, and removal of nonnative trout where necessary (USFWS 
2009, pp. 67, 75-76). We expect that implementation of the CCP during 
the next 15 years will address a number of significant resource issues 
that affect grayling (e.g., riparian habitat condition, entrainment in 
irrigation ditches, increasing the extent of occupancy in the system). 
Nonetheless, actions similar to those planned inside the NWR will be 
needed on adjacent properties to reduce threats to the existing 
population of grayling in the Red Rock Lakes system.
Federal Power Act
    The Federal Power Act of 1920 (16 U.S.C. 791-828c, 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 provide upstream passage of fish, and such dams are believed 
to be one of the primary factors leading to the decline of Arctic 
grayling in the Missouri River basin (see discussion under Factor A, 
above). Consequently, we conclude that historically the Federal Power 
Act has not adequately protected Arctic grayling or its habitat. We 
anticipate this will remain a threat it in the foreseeable future 
because of future expiration dates of the FERC-licensed dams in the 
upper Missouri River basin.
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 
foreseeable future. As of November 2009, the Red Rocks watershed was in 
the pre-TMDL planning and assessment phase, but there was no 
significant TMDL plan development activity in the Madison River (see 
MDEQ 2010). Consequently, implementation of the CWA through an EPA-
approved TMDL plan began in 2009 for the Big Hole River watershed, but 
has yet to begin in other waters occupied by native Arctic grayling in 
the upper Missouri River. The CWA does not appear to be adequate to 
protect the Missouri River DPS of Arctic grayling, but implementation 
of TMDL plans should improve habitat conditions for Big Hole River 
grayling in the foreseeable future.

Montana State Laws and Regulations

    Arctic grayling is considered a species of special concern by 
Montana, but this is not a statutory or regulatory classification 
(Montana Natural Heritage Program 2010).

[[Page 54737]]

State Comprehensive Wildlife Conservation Strategies
    These strategies, while not State or national legislation, can help 
prioritize conservation actions within each State. Species and habitats 
named within each Comprehensive Wildlife Conservation Strategy (CWCS) 
may receive focused attention. The MFWP considers Arctic grayling as a 
Tier I conservation species under its CWCS and the Big Hole River also 
is a Tier I Aquatic Conservation Focus Area (Montana's Comprehensive 
Fish and Wildlife Conservation Strategy (MCFWCS) 2005, pp. 75-76).
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 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). Although these regulatory mechanisms would be 
expected to limit impacts to aquatic habitats in general, the decline 
of Arctic grayling in the Big Hole River, Madison River, and certain 
waters in the Red Rock Lakes system does not provide evidence that past 
implementation of these laws, regulations, and permitting processes has 
effectively limited impacts to Arctic grayling habitat. Thus, we have 
no basis for concluding that these same regulatory mechanisms are 
adequate to protect the Arctic grayling and its habitat now or in the 
foreseeable future.
Montana Water Use Act
    The implementation of Montana Water Use Act (Title 85: Chapter 2, 
Montana Codes Annotated) may not adequately address threats to Arctic 
grayling in basins where the allocation of water rights exceeds the 
available water (overallocation) and the water rights holders fully 
execute their rights (i.e., use all water legally available for 
diversion). 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). 
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 state-wide 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 2010, the Red Rock River system is currently 
being examined, and the Big Hole and Madison Rivers have temporary 
decrees (MDNRC 2010, entire). We anticipate the final adjudication of 
all the river basins in Montana that currently contain native Arctic 
grayling will be completed in the foreseeable future, but we do not 
know if this process will eliminate the overallocation of water rights.
Fishing 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 (MFWP 2010, p. 52). Catch-and-release 
regulations also are in effect for Ennis Reservoir on the Madison River 
(MFWP 2010, p. 61). Arctic grayling in Miner and Mussigbrod Lakes 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

[[Page 54738]]

(MFWP 2010, p. 52). 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

    We infer that current Federal and State regulatory mechanisms are 
inadequate to protect native Arctic grayling of the upper Missouri 
River. We conclude this because the regulatory mechanisms may only 
apply to specific populations (or parts of populations) depending on 
land ownership and jurisdiction, they have no track record of 
addressing significant threats to habitat, and they do not address the 
threat posed by nonnative trout.
    Regulatory mechanisms on Federal lands may be adequate to protect 
certain fragments of Arctic grayling habitat or isolated populations 
(e.g., Miner and Mussigbrod Lakes). However, the extirpation of more 
than one lake population within the Beaverhead-Deerlodge National 
Forest (e.g., Elk Lake - Oswald 2000, p. 10; Hamby Lake - Oswald 2005a, 
pers. comm.) suggests the existing regulatory mechanisms may not be 
sufficient. Difficulties in coordinating land and water use across 
jurisdictional boundaries (State, Federal, private) within a watershed 
also present challenges for coordinated management of Arctic grayling. 
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 scope to protect 
the species.
    Conceivably, application of existing regulations concerning 
occupied Arctic grayling habitat in the upper Missouri River basin 
(e.g., CWA, FLPMA, NFMA, SMZL, SPA) should promote and ensure the 
persistence of Arctic grayling because these regulations were 
promulgated, to some extent, to limit impacts of human activity on the 
environment. However, based on the current status of the DPS and the 
degradation of habitat and declines in populations observed in the past 
20 to 30 years, during which time many of the above regulatory 
mechanisms have been in place, we have no basis to conclude that they 
have adequately protected grayling up to this time. In other words, 
existing regulations theoretically limit threats to Arctic grayling, 
but in practice have not done so. We suspect that incomplete or 
inconsistent application of these regulatory mechanisms and 
jurisdictional difficulties (State vs. Federal regulations, private vs. 
public lands) relative to the distribution of Arctic grayling may be 
partially responsible. Other regulatory mechanisms simply require 
disclosure (e.g., NEPA) and do not necessarily mandate protection for a 
species or its habitat. Consequently, we believe that existing 
regulatory mechanisms that deal with land and water management have not 
demonstrably reduced threats to Arctic grayling in the past, and we 
have no basis to conclude that they are adequate now or will be in the 
future.
    Existing regulatory mechanisms do not directly address threats 
posed by nonnative brook trout, brown trout, or rainbow trout (see 
Factor C discussion, above). One exception is that the Red Rock Lakes 
NWR CCP does consider removal of nonnative trout to be a possible 
action to benefit Arctic grayling, but this may not apply to occupied 
habitat outside the NWR, so the CCP is likely to only address this 
threat for a portion of the population.
    For the reasons described above, we conclude that the inadequacy of 
existing regulatory mechanisms poses a current threat to native Arctic 
grayling of the upper Missouri River. We do not anticipate any changes 
to the existing regulatory mechanisms, thus we conclude that the 
inadequacy of existing regulatory mechanisms is a threat in the 
foreseeable future.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

Drought

    Drought appears to be a significant natural factor that threatens 
Arctic grayling populations in streams and rivers in the upper Missouri 
River basin. 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; to 
a reduced volume of thermally suitable habitat; and to an increased 
frequency of water temperatures above the physiological limits for 
optimum growth and survival in Arctic grayling. 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). 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). 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 do 
occur. For example, both the Upper and Lower Red Rock Lakes are very 
shallow (Mogen 1996, p. 7). Reduced water availability during drought 
would result in further shallowing (loss of habitat volume) that can 
lead to increased temperatures in summer and the likelihood of complete 
freezing or anoxia (lack of oxygen) in winter.
    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). Similarly, lack of success with fluvial Arctic grayling 
restoration efforts elsewhere in the upper Missouri River basin also 
has been attributed, in part, to drought (Lamothe and Magee 2004a, p. 
28).
    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. Therefore, we 
expect the threat of drought to be most pronounced for Arctic grayling 
populations in the Big Hole River, Madison River-Ennis Reservoir, and 
Red Rock Lakes. We do not know whether drought has or is currently 
limiting Arctic grayling populations in Miner and Mussigbrod Lakes, as 
there are few monitoring data for these populations. Arctic grayling in 
Miner and Mussigbrod Lakes presumably use inlet or outlet streams for 
spawning; thus, if severe drought occurs during spawning and before 
subsequent emigration of YOY grayling to the rearing lakes, then 
population-level effects are possible. Overall, we conclude that 
drought has been a past threat, is a current threat, and will continue 
to be a threat to Arctic grayling of the upper Missouri River basin, 
especially for those populations in the

[[Page 54739]]

Big Hole River, Madison River-Ennis Reservoir, and Red Rock Lakes. 
Successful implementation of the Big Hole Grayling CCAA may partially 
ameliorate 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) to negatively affect 
suitable habitat for Arctic grayling. We expect the magnitude of the 
threat from drought to increase in the foreseeable future under the 
anticipated air temperature and precipitation trends projected by 
climate change models (discussed in detail below).

Climate Change

    Climate is influenced primarily by long-term patterns in air 
temperature and precipitation. The Intergovernmental Panel on Climate 
Change (IPCC) has concluded that climate warming is unequivocal, and is 
now evident from observed increases in global average air and ocean 
temperatures, widespread melting of snow and ice, and rising global 
mean sea level (IPCC 2007, pp. 30-31). Continued greenhouse gas 
emissions at or above current rates are expected to cause further 
warming (IPCC 2007, p. 30). Eleven of the 12 years from 1995 through 
2006 rank among the 12 warmest years in the instrumental record of 
global average near-surface temperature since 1850 (ISAB 2007, p.7; 
IPCC 2007, p. 30). During the last century, mean annual air temperature 
increased by approximately 0.6 [deg]C (1.1 [deg]F) (IPCC 2007, p. 30). 
Warming appears to be accelerating in recent decades, as the linear 
warming trend over the 50 years from 1956 to 2005 (average 0.13 [deg]C 
or 0.24 [deg]F per decade) is nearly twice that for the 100 years from 
1906 to 2005 (IPCC 2007, p. 30). Climate change scenarios estimate that 
the mean air temperature could increase by over 3 [deg]C (5.4 [deg]F) 
by 2100 (IPCC 2007, pp. 45-46). The IPCC also projects that there will 
likely be regional increases in the frequency of hot extremes, heat 
waves, and heavy precipitation, as well as greater warming in high 
northern latitudes (IPCC 2007, p. 46). We recognize that there are 
scientific differences of opinion on many aspects of climate change, 
including the role of natural variability in climate. In our analysis, 
we rely primarily on synthesis documents (IPCC 2007; ISAB 2007; Karl et 
al. 2009) that present the consensus view of a large number of experts 
on climate change from around the world. We found that these synthesis 
reports, as well as the scientific papers used in those reports, or 
resulting from those reports, represent the best available scientific 
information we can use to inform our decision. Where possible, we used 
empirical data or projections specific to the western United States, 
which includes the range of Arctic grayling in the Missouri River 
basin, and focused on observed or expected effects on aquatic systems.
    Water temperature and hydrology (stream flow) are sensitive to 
climate change, and influence many of the basic physical and biological 
processes in aquatic systems. For ectothermic organisms like fish, 
temperature sets basic constraints on species' distribution and 
physiological performance, such as activity and growth (Coutant 1999, 
pp. 32-52). Stream hydrology not only affects the structure of aquatic 
systems across space and time, but influences the life-history and 
phenology (timing of life-cycle events) of aquatic organisms, such as 
fishes. For example, the timing of snowmelt runoff can be an 
environmental cue that triggers spawning migrations in salmonid fishes 
(Brenkman et al. 2001, pp. 981, 984), and the timing of floods relative 
to spawning and emergence can strongly affect population establishment 
and persistence (Fausch et al. 2001, pp. 1438, 1450). Significant 
trends in water temperature and stream flow have been observed in the 
western United States (Stewart et al. 2005, entire; Kaushal et al. 
2010, entire), and climatic forcing caused by increased air 
temperatures and changes in precipitation are partially responsible.
    Warming patterns in the western United States are not limited to 
streams. In California and Nevada, water surface temperatures have 
increased by an average of 0.11 [deg]C (0.2 [deg]F) per year since 1992 
and at a rate twice that of the average minimum air surface temperature 
(Schneider et al. 2009, p. L22402). In the western United States, 
runoff from snowmelt occurs 1 to 4 weeks earlier (Regonda et al. 2005, 
p. 380; Stewart et al. 2005, pp. 1136, 1141; Hamlett et al. 2007, p. 
1468), presumably as a result of increased temperatures (Hamlet et al. 
2007, p. 1468), increased frequency of melting (Mote et al. 2005, p. 
45), and decreased snowpack (Mote et al. 2005, p. 41).
    Trends in decreased water availability also are apparent across the 
Pacific Northwest. For example, Luce and Holden (2009, entire) found a 
tendency toward more extreme droughts at 72 percent of the stream flow 
gages they examined across Idaho, Montana, Oregon, and Washington.
    Climate forcing may be directly or indirectly altering those 
habitats. Long-term water temperature data are not available for sites 
currently occupied by native Arctic grayling populations (e.g., Big 
Hole River, Red Rock Creek); however, if trends in air temperature are 
consistently related to increases in water temperature (Isaak et al. 
2010, p. 1), then a regional pattern of increased water temperature is 
likely, and it is reasonable to assume that Arctic grayling in the Big 
Hole River, Red Rock Creek, and Madison River near Ennis Reservoir also 
have experienced the same trend. Mean annual air temperature recorded 
at Lakeview, Montana, near the Red Rock Lakes between 1948 and 2005 did 
not increase significantly, although mean temperatures in March and 
April did show a statistically significant increase consistent with 
earlier spring warming observed elsewhere in North America during 
recent decades (USFWS 2009, pp. 36-39).
    The effect of such warming would be similar to that described for 
increased temperatures associated with stream dewatering (see 
discussion under Factor A), namely there has been an increased 
frequency of high water temperatures that may be above the 
physiological limits for survival or optimal growth for Arctic 
grayling, which is considered a cold-water (stenothermic) species 
(Selong et al. 2001, p. 1032). Changes in water temperature also 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 
may be consistent with the hypothesis that stream warming is 
facilitating encroachment. Further study is needed to evaluate this 
hypothesis.
    Observations on flow timing in the Big Hole River, upper Madison 
River, and Red Rock Creek indicate a tendency toward earlier snowmelt 
runoff (USFWS 2010b). These hydrologic alterations may be biologically 
significant for Arctic grayling in the Missouri River basin because 
they typically spawn

[[Page 54740]]

prior to the peak of snowmelt runoff (Shepard and Oswald 1989, p. 7; 
Mogen 1996, pp. 22-23; Rens and Magee 2007, pp. 6-7). A trend toward 
earlier snowmelt runoff could thus result in earlier average spawning 
dates, with potential (and presently unknown) implications for spawning 
success and growth and survival of fry. Water availability has 
measurably decreased in some watersheds occupied by Arctic grayling. 
For example, mean annual precipitation recorded at Lakeview, Montana, 
near the Red Rock Lakes, decreased significantly between 1948 and 2005 
(USFWS 2009, pp. 36-39).
    The western United States appears to be warming faster than the 
global average. In the Pacific Northwest, regionally averaged 
temperatures have risen 0.8 [deg]C (1.5 [deg]F) over the last century 
and as much as 2 [deg]C (4 [deg]F) in some areas. They are projected to 
increase by another 1.5 to 5.5 [deg]C (3 to 10 [deg]F) over the next 
100 years (Karl et al. 2009, p. 135). For the purposes of this finding, 
we consider the foreseeable future for anticipated climate changes as 
approximately 40 years, because various global climate models (GCM) and 
emissions scenarios give consistent predictions within that timeframe 
(Ray et al. 2010, p. 11). We used a similar foreseeable future to 
consider climate change projects in other 12-month findings (see 
American pika (Ochotona princeps) - 75 FR 6448, February 9, 2010). 
While projected patterns of warming across North America are generally 
consistent across different GCMs and emissions scenarios (Ray et al. 
2010, p. 22), there tends to be less agreement among models for whether 
mean annual precipitation will increase or decrease, but the models 
seem to indicate an increase in precipitation in winter and a decrease 
in summer (Ray et al. 2010, pp. 22-23). In the foreseeable future, 
natural variation will likely confound a clear prediction for 
precipitation based on current climate models (Ray et al. 2010, p. 29). 
Although there is considerable uncertainty about how climate will 
evolve at any specific location, statistically downscaled climate 
projection models (models that predict climate at finer spatial 
resolution than GCMs) for the Pacific Northwest also support widespread 
warming, with warmer temperature zones shifting to the north and upward 
in elevation (Ray et al. 2010, pp. 23-24).
    The land area of the upper Missouri River basin also is predicted 
to warm (Ray et al. 2010, p. 23), although currently occupied Arctic 
grayling habitat tends be in colder areas of moderate-to-high 
elevation. Four out of five populations are at approximately 1,775 to 
2,125 m (5,860 to 7,012 ft) (Peterson and Ardren 2009, p. 1761). 
Presumably, any existing trends in water temperature increase and 
earlier snowmelt runoff in streams and rivers that is being forced by 
increases in air temperature should continue. To the extent that these 
trends in water temperature and hydrology already exist in habitats 
occupied by native Arctic grayling, they should continue into the 
foreseeable future. In general, climate change is expected to 
substantially reduce the thermally suitable habitat for coldwater fish 
species (Keleher and Rahel 1996, pp. 1, 6-11; Mohseni et al. 2003, pp. 
389, 401; Flebbe et al. 2006, p. 1371, 1378; Rieman et al. 2007, pp. 
1552, 1559). The range of native Arctic grayling in the upper Missouri 
River has already contracted significantly during the past 50 to 100 
years (Vincent 1962, pp. 96-121; Kaya 1992, pp. 49-51). The currently 
occupied native Arctic grayling habitat tends be in colder areas of 
moderate-to-high elevation that may, to some extent, be more resistant 
to large or rapid changes in hydrology (Regonda et al. 2005, p. 380; 
Stewart et al. 2005, p. 1142) or perhaps stream warming.
    Nonetheless, we do not expect these habitats to be entirely immune 
from effects of climate warming, so we expect that climate change could 
lead to further range contractions of Arctic grayling of the upper 
Missouri River and may increase the species' risk of extinction over 
the next 30 to 40 years as climate impacts interact with existing 
stressors (Karl et al. 2009, p. 81), such as habitat degradation, 
stream dewatering, drought, and interactions with nonnative trout that 
are already affecting the DPS. We anticipate that implementation of the 
Big Hole Grayling CCAA may partially compensate for, or reduce the 
severity of, likely effects of climate change on Arctic grayling in the 
Big Hole River. However, if current projections are realized, climate 
change is likely to exacerbate the existing primary threats to Arctic 
grayling outside the Big Hole River. The IPCC projects that the changes 
to the global climate system in the 21st century will likely be greater 
than those observed in the 20th century (IPCC 2007, p. 45); therefore, 
we anticipate that these effects will continue and likely increase into 
the foreseeable future. We do not consider climate change in and of 
itself to be a significant factor in our determination of whether 
Arctic grayling of the upper Missouri River is warranted for listing 
because of the greater imminence and magnitude of other threats (e.g., 
Factor A: habitat degradation, Factor C: nonnative trout). However, we 
expect the severity and scope of key threats (habitat degradation and 
fragmentation, stream dewatering, and nonnative trout) to increase in 
the foreseeable future because of climate change effects that are 
already measureable (i.e., increased water temperature, increased 
frequency of extreme drought, changes in runoff patterns). Thus, we 
consider that climate change will potentially intensify some of the 
significant current threats to all Arctic grayling populations in the 
DPS. After approximately 40 years, the variation in GCM projections 
based on the various emissions scenarios begins to increase 
dramatically (Ray et al. 2010 pp. 12-13), so 40 years represents the 
foreseeable future in terms of the extent to which the effects of 
climate change (a major environmental driver) can reliably be modeled 
or predicted. Thus we conclude that climate change constitutes a threat 
in the Missouri DPS of Arctic grayling in the foreseeable future.

Stochastic (Random) Threats

    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 (random) stochastic 
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). Based on these principles, the upper 
Missouri River DPS of Arctic grayling may face current and future 
threats from stochastic processes that act on small, reproductively 
isolated populations.
    The upper Missouri River DPS of Arctic grayling exists as a 
collection of small, isolated populations (Figure 2; Peterson and 
Ardren 2009, entire). Patterns of dispersal among extant Arctic 
grayling populations have been constrained dramatically by the presence 
of dams. The inability of fish to move between populations limits 
genetic exchange, the maintenance of local populations (demographic 
support; Hilderbrand 2003, p. 257), and recolonization of habitat 
fragments (reviewed by Fausch et al. 2006, pp. 8-9). Isolated 
populations cannot offset the random loss of genetic variation (Fausch 
et al. 2006, p. 8). This in turn can lead to loss of phenotypic 
variation and evolutionary potential (Allendorf and Ryman 2002, p. 54). 
Relative to the presumed historical condition of

[[Page 54741]]

connectivity among most of the major rivers in the upper Missouri River 
basin, the extant native Arctic grayling populations face both genetic 
and demographic threats from isolation, both currently and in the 
foreseeable future.
    Four of the five individual populations in the upper Missouri River 
DPS of Arctic grayling are at low-to-moderate abundance (see Population 
Status and Trends for Native Arctic Grayling of the Upper Missouri 
River, above). Individually, small populations 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 
for genetic effective population sizes observed in the Big Hole River, 
Miner Lakes, Madison River, and Red Rock Lakes populations are above 
the level at which inbreeding is an immediate concern, but below the 
level presumed to provide the genetic variation necessary to conserve 
long-term adaptive potential (Peterson and Ardren 2009, pp. 1767, 
1769). Historically, effective population sizes of Arctic grayling in 
the Missouri River were estimated to be 1 or 2 orders of magnitude 
greater (10 to 100 times) than those currently observed (Peterson and 
Ardren 2009, pp. 1767). Loss of genetic variation relative to the 
historical condition thus represents a threat to Arctic grayling in the 
foreseeable future.
    Only the Big Hole River population expresses the migratory fluvial 
ecotype that presumably dominated in the upper Missouri River basin 
(Kaya 1992, pp. 47-50); therefore, the DPS lacks functional redundancy 
in ecotypes. 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 lack of 
additional fluvial populations represents a current threat to the upper 
Missouri River DPS. Reintroduction efforts have been ongoing to reduce 
this threat, but have not yet produced a self-sustaining population at 
any of the reintroduction sites (Rens and Magee 2007, pp. 21-38). 
Future successful reintroductions may reduce this threat, but at the 
present time we consider the threat to extend into the foreseeable 
future.
    Populations of Arctic grayling in the upper Missouri River DPS are 
for the most part widely separated from one another, particularly those 
populations in the Big Hole, Madison, and Red Rock drainages (see 
Figure 2). Thus, they do not appear to all share a common risk of being 
extirpated by a rare, high-magnitude environmental disturbance (i.e., 
catastrophe). Three of the five populations are within the same 
watershed (Big Hole River, Miner Lakes, and Mussigbrod Lake 
populations), so collectively these three populations would be at 
greater risk. Individually, each population appears to be at 
substantial risk of extirpation by catastrophe from one or more factor, 
such as restricted distribution (Miner Lakes, Mussigbrod Lake), low 
population abundance (Madison Lake, Red Rocks Lakes , Big Hole River), 
and concentration of spawning primarily in a single, discrete location 
(Red Rock Lakes). The Big Hole River population may be at a 
comparatively lower risk from catastrophe because individuals still 
spawn at multiple locations within the drainage (Rens and Magee 2007, 
p. 13).
    The population viability analysis (PVA) demonstrates that four of 
the five extant populations in the upper Missouri River DPS of Arctic 
grayling are at moderate (at least 13 percent) to high risk (more than 
50 percent) of extinction from random environmental variation. In this 
context, random environmental variation is simply considered to be 
common environmental fluctuations, such as drought, floods, debris 
flows, changes in food availability, etc. that affect population size 
and population growth. These PVA analyses assume that variation in 
annual population growth increases as population size decreases (Rieman 
and McIntyre 1993, pp. 43-46), which seems a reasonable assumption 
given the large inter-annual variability in relative abundance and 
recruitment observed in some Arctic grayling populations in Montana 
(e.g., Big Hole River) (Magee et al. 2005, pp. 27-28). Simply stated, 
smaller populations are more likely to go extinct even if they are 
stable because they are already close to the extinction threshold, and 
random environmental events can drive their abundance below that 
threshold. Consequently, we believe that extinction risk from random 
environmental variation (droughts, floods, etc.) represents a 
significant threat in the foreseeable future based on the PVA.
    We are unsure whether chance variation in the fates of individuals 
within a given year (demographic stochasticity) is a current threat to 
the upper Missouri River DPS of Arctic grayling. The magnitude of 
demographic stochasticity is inversely related to population size 
(Morris and Doak 2002, pp. 22-23), but we do not know whether any of 
the Arctic grayling populations currently exist at or below an 
abundance where demographic stochasticity is likely.
    Overall, we conclude that the upper Missouri River DPS of Arctic 
grayling faces threats from population isolation, loss of genetic 
diversity, and small population size, which all interact to increase 
the likelihood that random environmental variation or a catastrophe can 
extirpate an individual population. The uncertainty of PVA predictions 
increases dramatically after about 25 to 30 years, so we feel this 
represents a foreseeable future in terms of stochastic threats to the 
DPS. Lack of connectivity among extant populations and lack of 
replicate populations for the fluvial ecotype represent current 
threats. Threats from reduced genetic diversity, environmental 
variation, or catastrophe are threats in the foreseeable future, 
because their effects may take longer to play out (i.e., link between 
genetic diversity and adaptation) and are based on probabilistic 
inference concerning the magnitude of variation in population growth, 
environmental fluctuation, and periodic disturbance.

Summary of Factor E

    Based on the information available at this time, we conclude that 
drought represents a current and future threat to native Arctic 
grayling in the upper Missouri River system. Drought can affect fish 
populations by reducing stream flow volumes, which leads to dewatering 
and high temperatures that can limit connectivity among spawning, 
rearing, and sheltering habitats; a reduced volume of thermally 
suitable habitat; and an increased frequency of water temperatures 
above the physiological limits for optimum growth and survival.
    Climate projections suggest that the frequency and severity of 
drought is expected to increase; thus the magnitude of drought-related 
threats and impacts also may increase. We anticipate the effects of 
drought to be most pronounced in streams, rivers, and shallow lakes; 
therefore, the Big Hole River, Madison River-Ennis Reservoir, and Red 
Rock Lakes populations are likely to be most threatened by drought. 
There is evidence for increasing air temperatures and changing 
hydrologic pattern resulting from climate change in the Pacific 
Northwest and intermountain West, and we conclude that climate change 
is a secondary threat that can interact with and magnify the effects of 
primary threats, such as drought, stream dewatering from irrigation 
withdrawals, and the outcome of interactions with nonnative trout 
species that have higher thermal tolerances. We anticipate that climate

[[Page 54742]]

change will remain a threat in the foreseeable future, but that 
conservation programs that increase connectivity among refuge habitats 
and improve stream flows (e.g., Big Hole Grayling CCAA) will to some 
extent mitigate or lessen the effects of climate change. Climate change 
effects should be most pronounced in those same habitats and 
populations most strongly affected by water availability (Big Hole 
River, Madison River-Ennis Reservoir, Red Rock Lakes), but lake 
habitats also can be affected (Schneider et al. 2009, entire), so 
threats likely extend to the other populations in the DPS (Miner and 
Mussigbrod Lakes).
    The Missouri River DPS of Arctic grayling currently exists as a 
collection of small, isolated populations that face some current and 
foreseeable threats from a collection of random (stochastic) processes 
characteristic of small populations, such as loss of genetic diversity 
because of habitat fragmentation and isolation, and individual 
populations face increased risk of extirpation from random 
environmental variation (results of PVA) and catastrophe.

Finding

    As defined by the DPS Policy, we determined that the native Arctic 
grayling of the upper Missouri River constitutes a listable entity 
under the ESA. We also considered the appropriateness of listing 
separate distinct population segments based on each of the ecotypes 
(fluvial and adfluvial) that occur naturally in Arctic grayling 
populations in the Missouri River basin. The best scientific 
information indicates these ecotypes share a recent evolutionary 
history and the populations do not cluster genetically by life-history 
type. Maintaining life-history diversity increases the likelihood that 
a species (or DPS) will maintain both the genetic diversity and 
evolutionary flexibility to deal with future environmental challenges. 
Consequently we feel that preservation of both native ecotypes in their 
native habitats is essential to conservation of the DPS; thus we have 
determined that a single DPS that includes both ecotypes is most 
appropriate from both a practical management and conservation 
perspective. We refer to this DPS as the Missouri River DPS of Arctic 
grayling. As discussed above, we do not include the nonnative Arctic 
grayling in the DPS, based on intent of the Act, IUCN guidelines, and 
NMFS policy. The Service does not currently have a specific policy 
concerning nonnative species, therefore we will investigate this topic 
in more detail during the proposed rulemaking process.
    As required by the ESA, we considered the five factors in assessing 
whether the Missouri River DPS of Arctic grayling is endangered or 
threatened throughout all or a significant portion of its range. We 
carefully examined the best scientific and commercial information 
available regarding the past, present, and future threats faced by the 
DPS. We reviewed the petition, information available in our files, 
other available published and unpublished information, and we consulted 
with recognized species experts and other Federal, State, and tribal 
agencies. On the basis of the best scientific and commercial 
information available, we find that listing the DPS as endangered or 
threatened is warranted. We will make a determination on the status of 
the species as endangered or threatened when we do a proposed listing 
determination. However, as explained in more detail below (see 
Preclusion and Expeditious Progress section), an immediate proposal of 
a regulation implementing this action is precluded by higher priority 
listing actions, and progress is being made to add or remove qualified 
species from the Lists of Endangered and Threatened Wildlife and 
Plants.
    The historical range of Arctic grayling in the upper Missouri River 
basin has declined dramatically in the past century. The five remaining 
indigenous populations are isolated from one another by dams or other 
factors. Moreover, three of these five populations (Big Hole, Madison-
Ennis, Red Rocks) appear to be at low abundance (perhaps no more than 
650 to 2,000 adults per population) and have declined in abundance 
during the past few decades. The Big Hole River contains the only 
remaining example of the fluvial ecotype in the DPS, and the effective 
number of breeding adults declined by half during the past 15 years. 
Populations of Arctic grayling in two small lakes in the Big Hole River 
drainage (Miner and Mussigbrod) appear to be more abundant, and perhaps 
more secure than the other native populations.
    This status review identified threats to the DPS related to Factors 
A, C, D, and E (see Table 5). All populations face potential threats 
from competition with and predation by nonnative trout (Factor C) now 
and in the foreseeable future. The magnitude of this threat likely 
varies by Arctic grayling population, and is greater in locations where 
multiple species of nonnative trout are present, abundant, and comprise 
a large proportion of the salmonid biomass (e.g., Big Hole River, 
Madison River-Ennis Reservoir, Red Rock Lakes). Most populations face 
threats that result from the alteration of their habitats (Factor A), 
such as habitat fragmentation from large dams or smaller irrigation 
diversion structures, stream dewatering, high summer water 
temperatures, loss of riparian habitats, and entrainment in irrigation 
ditches (see Table 5). Severe drought (Factor E) likely affects all 
populations by reducing water availability and reducing the extent of 
thermally suitable habitat, but we presume the effects of drought are 
most pronounced for Arctic grayling that reside primarily in streams 
and rivers (Big Hole River) or shallow lakes (Madison River-Ennis 
Reservoir, Red Rock Lakes). We did not consider climate change (Factor 
E) in and of itself to be a significant current threat, but if current 
climate changes projections are realized, we expect that climate change 
will influence severity and scope of key threats (habitat degradation 
and fragmentation, stream dewatering, interactions with nonnative 
trout, drought). As applied, existing regulatory mechanisms (Factor D) 
do not appear to be adequate to address primary threats to grayling 
(e.g., stream dewatering, loss of riparian habitats), as at least three 
native Arctic grayling populations have continued to decline in 
abundance in recent decades.

[[Page 54743]]



              TABLE 5. Current and Foreseeable Threats to Individual Populations of Native Arctic Grayling in the Upper Missouri River DPS.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Madison River-Ennis
           Threat Factor                 Big Hole River            Miner Lakes          Mussigbrod Lake           Reservoir           Red Rocks Lakes
--------------------------------------------------------------------------------------------------------------------------------------------------------
A                                    Dams/habitat                                    Dams/habitat           Dams/habitat           Dams/habitat
                                     fragmentation\a\......                          fragmentation........  fragmentation........  fragmentation
                                     Dewatering\a\.........                                                 Thermal stress.......  Dewatering
                                     Thermal stress\a\.....                                                                        Thermal stress
                                     Entrainment\a\........                                                                        Entrainment
                                     Riparian habitat                                                                              Riparian habitat loss
                                      loss\a\.                                                                                     Sediments
--------------------------------------------------------------------------------------------------------------------------------------------------------
C                                    Predation &             Predation &             Predation &            Predation &            Predation &
                                      competition with        competition with        competition with       competition with       competition with
                                      nonnative trout         nonnative trout         nonnative trout        nonnative trout        nonnative trout
--------------------------------------------------------------------------------------------------------------------------------------------------------
D                                    Inadequate              Inadequate              Inadequate             Inadequate             Inadequate
                                      regulations\b\          regulations\b\          regulations\b\         regulations\b\         regulations\b\
                                     (nonnative trout,.....   (nonnative trout,       (nonnative trout,     (nonnative trout,....  (nonnative trout,
                                     continued population    extirpation of other    extirpation of other   federally-permitted    continued population
                                      decline).               lake populations of     lake populations of    dam,.                  decline)
                                                              grayling).              grayling).            continued population
                                                                                                             decline).
--------------------------------------------------------------------------------------------------------------------------------------------------------
E                                    Reduced genetic         Reduced genetic         Drought                Reduced genetic        Reduced genetic
                                     diversity, low........  diversity, low........  Climate change\c\....  diversity, low.......  diversity, low
                                     abundance, random       abundance, random                              abundance, random      abundance, random
                                      events.                 events.                                        events.                events
                                     Drought...............  Drought...............                         Drought..............  Drought
                                     Climate change\c\.....  Climate change\c\.....                         Climate change\c\....  Climate change\c\
                                     No replicate of
                                      fluvial ecotype.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The magnitude of current threats to the majority of the extant population or its habitat are expected be reduced in the foreseeable future from
  implementation of a formalized conservation plan (i.e., Big Hole Grayling CCAA).
\b\ Terms in parenthesis characterize the inadequacy of the regulatory mechanisms in terms of not addressing specific threats (e.g., nonnative trout,
  Factor C; dams, Factor A) or having no observed record of success with protecting existing populations (continued population decline, extirpation of
  other similarly situated populations).
\c\ Threats believed to be of secondary importance or that interact with primary threats.

    In the Big Hole River, ongoing implementation of a formalized 
conservation program (Big Hole Grayling CCAA) with substantial 
participation from non-Federal landowners and State and Federal agency 
partners should significantly reduce many of the habitat-related 
threats to that population in the foreseeable future. In the Red Rock 
Lakes NWR, implementation of a CCP should reduce many of the primary 
threats to Arctic grayling that occur within the NWR's boundary, but 
threats to Arctic grayling and its habitat also exist outside the 
administrative boundary of the CCP.
    Four of five populations appear to be at risk of extirpation in the 
foreseeable future (next 20 to 30 years) from random fluctuations in 
environmental conditions (e.g., precipitation, food availability, 
density of competitors, etc.), simply because they are at low abundance 
and cannot receive demographic support from other native populations 
(Factor E). Low abundance and isolation also raises concerns that the 
loss of genetic variation from chance events (genetic drift) also may 
be a threat in some populations. Maintaining life-history diversity is 
important for species conservation given anticipated environmental 
challenges such as those anticipated under climate change, so having 
only a single population of the fluvial ecotype represents a 
significant threat to that ecotype's long-term persistence. A 
reintroduction program designed to address this threat has been 
implemented for more than a decade and has made some recent technical 
advances in the production of Arctic grayling fry. Natural reproduction 
by grayling has been observed at a re-introduction site in the Ruby 
River. At least 5 to 10 more years of monitoring is needed for us to 
establish that the reintroduced fish in the Ruby River constitute a 
viable population.
    We reviewed the available information to determine if the existing 
and foreseeable threats render the species at risk of extinction now 
such that issuing an emergency regulation temporarily listing the 
species under section 4(b)(7) of the ESA is warranted. We determined 
that issuing an emergency regulation temporarily listing the DPS is not 
warranted at this time because there are five populations in the DPS 
and the probability of simultaneous extinction of all five populations 
is low, as the populations are physically discrete and isolated from 
one another such that a natural or human-caused catastrophe is not 
likely to extirpate all populations at once. In addition, the remaining 
population that expresses the fluvial ecotype (Big Hole River) is 
subject to ongoing implementation of a formalized conservation 
agreement (Big Hole Grayling CCAA) with adaptive management 
stipulations if Arctic grayling population goals are not being met 
(MFWP et al. 2006, pp. 60-61), and provisions to rescue Arctic grayling 
or address alteration to habitat in the event of a large-magnitude 
disturbance such as a debris flow or flood (MFWP 2006, pp. 85-86).

Listing Priority Number

    The Service adopted guidelines on September 21, 1983 (48 FR 43098), 
to establish a rational system for utilizing available resources for 
the highest priority species when adding species to the Lists of 
Endangered or Threatened Wildlife and Plants or reclassifying species 
listed as threatened to endangered status. These guidelines, titled 
``Endangered and Threatened Species Listing and Recovery Priority 
Guidelines'' address the immediacy and magnitude of threats, and the 
level of taxonomic distinctiveness by assigning priority in descending 
order to

[[Page 54744]]

monotypic genera (genus with one species), full species, and subspecies 
(or equivalently, distinct population segments of vertebrates).
    As a result of our analysis of the best available scientific and 
commercial information, we assigned the native Arctic grayling of the 
upper Missouri River a Listing Priority Number (LPN) of 3 based on our 
finding that the DPS faces threats that are of high magnitude and are 
imminent. These primary threats include the present or threatened 
destruction, modification, or curtailment of its habitat; competition 
with and predation by nonnative trout; inadequacy of existing 
regulatory mechanisms to address all threats; extinction risk from 
small population size and isolation; drought; and lack of replication 
of the fluvial life history.
    Under the Service's guidelines, the magnitude of threat is the 
first criterion we look at when establishing a listing priority. The 
guidance indicates that species with the highest magnitude of threat 
are those species facing the greatest threats to their continued 
existence. These species receive the highest listing priority. We 
consider the threats that the native Arctic grayling of the upper 
Missouri River faces to be high in magnitude because many of the 
threats that we analyzed are present throughout the range and currently 
impact the DPS to varying degrees (e.g., habitat fragmentation, 
nonnative trout, inadequate regulatory mechanisms), and will continue 
to impact the DPS into the future. The threats that are of high 
magnitude include present or threatened destruction, modification, or 
curtailment of its habitat; competition with and predation by nonnative 
trout; inadequacy of existing regulatory mechanisms to address all 
threats; extinction risk from small population size and isolation and 
vulnerability to catastrophes; drought; and lack of replication of the 
fluvial life-history. Also, the small number (five) and size and 
isolation of the populations may magnify the impact of the other 
threats under Factors A and C.
    The DPS consists of only five populations, so loss of any 
individual population would incrementally increase the risk that the 
DPS will not persist. However, we presume that loss of the Big Hole 
River population would create the highest risk, as this population 
contains much of the genetic diversity present in the species within 
the Missouri River basin (Peterson and Ardren 2009, pp. 1763, 1768, 
1770) and is the only example of the fluvial ecotype. A conservation 
program (Big Hole Grayling CCAA) is being implemented to address 
habitat-related threats to the Big Hole River population, but the scope 
of the threat posed by nonnative trout remains high. Due to the scope 
and scale of the high magnitude threats and current isolation of 
already small populations, we conclude that the magnitude of threats to 
native Arctic grayling of the upper Missouri River is high.
    Under our LPN guidelines, the second criterion we consider in 
assigning a listing priority is the immediacy of threats. This 
criterion is intended to ensure that the species facing actual, 
identifiable threats are given priority over those for which threats 
are only potential or that are intrinsically vulnerable but are not 
known to be presently facing such threats. Not all the threats facing 
the DPS are imminent. For example, threats from climate change and 
catastrophe are reasonably certain to occur, and their effects may be 
particularly acute for small, isolated populations, but the specific 
nature and influence of these effects, although ongoing, are uncertain 
at this point. With relative certainty, we can project that climate 
change effects will exacerbate other ongoing effects throughout the 
DPS. In contrast, we have factual information that some threats are 
imminent because we have factual information that the threats are 
identifiable and that the DPS is currently facing them in many areas of 
its range. These other threats are covered in detail in the discussions 
under Factors A and C of this finding and include habitat 
fragmentation, stream dewatering, and riparian degradation from 
agriculture and ranching; dams; and competition with and predation by 
nonnative trout. Therefore, based on our LPN Policy, the threats are 
imminent (ongoing).
    The third criterion in our LPN guidelines is intended to devote 
resources to those species representing highly distinctive or isolated 
gene pools as reflected by taxonomy. We determined the native Arctic 
grayling of the upper Missouri River to be a valid DPS according to our 
DPS Policy. Therefore, under our LPN guidance, the native Arctic 
grayling of the upper Missouri River is assigned a lower priority than 
a species in a monotypic genus or a full species that faces the same 
magnitude and imminence of threats. Therefore, we assigned the native 
Arctic grayling of the upper Missouri River an LPN of 3 based on our 
determination that the DPS faces threats that are overall of high 
magnitude and are imminent. An LPN of 3 is the highest priority that 
can be assigned to a distinct population segment. We will continue to 
monitor the threats to the native Arctic grayling of the upper Missouri 
River, and the DPS' status on an annual basis, and should the magnitude 
or the imminence of the threats change, we will revisit our assessment 
of LPN.

Preclusion and Expeditious Progress

    Preclusion is a function of the listing priority of a species in 
relation to the resources that are available and competing demands for 
those resources. Thus, in any given fiscal year (FY), multiple factors 
dictate whether it will be possible to undertake work on a proposed 
listing regulation or whether promulgation of such a proposal is 
warranted but precluded by higher priority listing actions.
    The resources available for listing actions are determined through 
the annual Congressional appropriations process. The appropriation for 
the Listing Program is available to support work involving the 
following listing actions: Proposed and final listing rules; 90-day and 
12-month findings on petitions to add species to the Lists of 
Endangered and Threatened Wildlife and Plants (Lists) or to change the 
status of a species from threatened to endangered; annual 
determinations on prior ``warranted but precluded'' petition findings 
as required under section 4(b)(3)(C)(i) of the ESA; critical habitat 
petition findings; proposed and final rules designating critical 
habitat; and litigation-related, administrative, and program-management 
functions (including preparing and allocating budgets, responding to 
congressional and public inquiries, and conducting public outreach 
regarding listing and critical habitat). The work involved in preparing 
various listing documents can be extensive and may include, but is not 
limited to: Gathering and assessing the best scientific and commercial 
data available and conducting analyses used as the basis for our 
decisions; writing and publishing documents; and obtaining, reviewing, 
and evaluating public comments and peer review comments on proposed 
rules and incorporating relevant information into final rules. The 
number of listing actions that we can undertake in a given year also is 
influenced by the complexity of those listing actions; that is, more 
complex actions generally are more costly. For example, during the past 
several years, the cost (excluding publication costs) for preparing a 
12-month finding, without a proposed rule, has ranged from 
approximately $11,000 for one species with a restricted range and 
involving a relatively uncomplicated analysis to $305,000 for

[[Page 54745]]

another species that is wide-ranging and involving a complex analysis.
    We cannot spend more than is appropriated for the Listing Program 
without violating the Anti-Deficiency Act (see 31 U.S.C. 
1341(a)(1)(A)). In addition, in FY 1998 and for each FY since then, 
Congress has placed a statutory cap on funds which may be expended for 
the Listing Program, equal to the amount expressly appropriated for 
that purpose in that FY. This cap was designed to prevent funds 
appropriated for other functions under the ESA (for example, recovery 
funds for removing species from the Lists), or for other Service 
programs, from being used for Listing Program actions (see House Report 
105-163, 105\th\ Congress, 1st Session, July 1, 1997).
    Recognizing that designation of critical habitat for species 
already listed would consume most of the overall Listing Program 
appropriation, Congress also put a critical habitat subcap in place in 
FY 2002 and has retained it each subsequent year to ensure that some 
funds are available for other work in the Listing Program: ``The 
critical habitat designation subcap will ensure that some funding is 
available to address other listing activities'' (House Report No. 107 - 
103, 107\th\ Congress, 1st Session, June 19, 2001). In FY 2002 and each 
year until FY 2006, the Service has had to use virtually the entire 
critical habitat subcap to address court-mandated designations of 
critical habitat, and consequently none of the critical habitat subcap 
funds have been available for other listing activities. In FY 2007, we 
were able to use some of the critical habitat subcap funds to fund 
proposed listing determinations for high-priority candidate species. In 
FY 2009, while we were unable to use any of the critical habitat subcap 
funds to fund proposed listing determinations, we did use some of this 
money to fund the critical habitat portion of some proposed listing 
determinations so that the proposed listing determination and proposed 
critical habitat designation could be combined into one rule, thereby 
being more efficient in our work. In FY 2010, we are using some of the 
critical habitat subcap funds to fund actions with statutory deadlines.
    Thus, through the listing cap, the critical habitat subcap, and the 
amount of funds needed to address court-mandated critical habitat 
designations, Congress and the courts have in effect determined the 
amount of money available for other listing activities. Therefore, the 
funds in the listing cap, other than those needed to address court-
mandated critical habitat for already listed species, set the limits on 
our determinations of preclusion and expeditious progress.
    Congress also recognized that the availability of resources was the 
key element in deciding, when making a 12-month petition finding, 
whether we would prepare and issue a listing proposal or instead make a 
``warranted but precluded'' finding for a given species. The Conference 
Report accompanying Public Law 97-304, which established the current 
statutory deadlines and the warranted-but-precluded finding, states (in 
a discussion on 90-day petition findings that by its own terms also 
covers 12-month findings) that the deadlines were ``not intended to 
allow the Secretary to delay commencing the rulemaking process for any 
reason other than that the existence of pending or imminent proposals 
to list species subject to a greater degree of threat would make 
allocation of resources to such a petition [that is, for a lower-
ranking species] unwise.''
    In FY 2010, expeditious progress is that amount of work that can be 
achieved with $10,471,000, which is the amount of money that Congress 
appropriated for the Listing Program (that is, the portion of the 
Listing Program funding not related to critical habitat designations 
for species that are already listed). However these funds are not 
enough to fully fund all our court-ordered and statutory listing 
actions in FY 2010, so we are using $1,114,417 of our critical habitat 
subcap funds in order to work on all of our required petition findings 
and listing determinations. This brings the total amount of funds we 
have for listing actions in FY 2010 to $11,585,417. Our process is to 
make our determinations of preclusion on a nationwide basis to ensure 
that the species most in need of listing will be addressed first and 
also because we allocate our listing budget on a nationwide basis. The 
$11,585,417 is being used to fund work in the following categories: 
compliance with court orders and court-approved settlement agreements 
requiring that petition findings or listing determinations be completed 
by a specific date; section 4 (of the ESA) listing actions with 
absolute statutory deadlines; essential litigation-related, 
administrative, and listing program-management functions; and high-
priority listing actions for some of our candidate species. In 2009, 
the responsibility for listing foreign species under the ESA was 
transferred from the Division of Scientific Authority, International 
Affairs Program, to the Endangered Species Program. Starting in FY 
2010, a portion of our funding is being used to work on the actions 
described above as they apply to listing actions for foreign species. 
This has the potential to further reduce funding available for domestic 
listing actions, although there are currently no foreign species issues 
included in our high-priority listing actions at this time. The 
allocations for each specific listing action are identified in the 
Service's FY 2010 Allocation Table (part of our administrative record).
    In FY 2007, we had more than 120 species with an LPN of 2, based on 
our September 21, 1983, guidance for assigning an LPN for each 
candidate species (48 FR 43098). Using this guidance, we assign each 
candidate an LPN of 1 to 12, depending on the magnitude of threats 
(high vs. moderate to low), immediacy of threats (imminent or 
nonimminent), and taxonomic status of the species (in order of 
priority: monotypic genus (a species that is the sole member of a 
genus); species; or part of a species (subspecies, distinct population 
segment, or significant portion of the range)). The lower the listing 
priority number, the higher the listing priority (that is, a species 
with an LPN of 1 would have the highest listing priority). Because of 
the large number of high-priority species, we further ranked the 
candidate species with an LPN of 2 by using the following extinction-
risk type criteria: IUCN Red list status/rank, Heritage rank (provided 
by NatureServe), Heritage threat rank (provided by NatureServe), and 
species currently with fewer than 50 individuals, or 4 or fewer 
populations. Those species with the highest IUCN rank (critically 
endangered), the highest Heritage rank (G1), the highest Heritage 
threat rank (substantial, imminent threats), and currently with fewer 
than 50 individuals, or fewer than 4 populations, comprised a group of 
approximately 40 candidate species (``Top 40''). These 40 candidate 
species have had the highest priority to receive funding to work on a 
proposed listing determination. As we work on proposed and final 
listing rules for these 40 candidates, we are applying the ranking 
criteria to the next group of candidates with an LPN of 2 and 3 to 
determine the next set of highest priority candidate species.
    To be more efficient in our listing process, as we work on proposed 
rules for these species in the next several years, we are preparing 
multi-species proposals when appropriate, and these may include species 
with lower priority if they overlap geographically or have the same 
threats as a species with an LPN of 2. In addition, available staff 
resources also are a factor in

[[Page 54746]]

determining high-priority species provided with funding. Finally, 
proposed rules for reclassification of threatened species to endangered 
are lower priority, since as listed species, they are already afforded 
the protection of the ESA and implementing regulations.
    We assigned the upper Missouri River DPS of Arctic grayling an LPN 
of 3, based on our finding that the DPS faces immediate and high 
magnitude threats from the present or threatened destruction, 
modification, or curtailment of its habitat; competition with and 
predation by nonnative trout; and the inadequacy of existing regulatory 
mechanisms. One or more of the threats discussed above occurs in each 
known population in the Missouri River basin. These threats are ongoing 
and, in some cases (e.g., nonnative species), considered irreversible. 
Under our 1983 Guidelines, a ``species'' facing imminent high-magnitude 
threats is assigned an LPN of 1, 2, or 3, depending on its taxonomic 
status. Work on a proposed listing determination for the upper Missouri 
River DPS of Arctic grayling is precluded by work on higher priority 
candidate species (i.e., species with LPN of 2); listing actions with 
absolute statutory, court ordered, or court-approved deadlines; and 
final listing determinations for those species that were proposed for 
listing with funds from previous FYs. This work includes all the 
actions listed in the tables below under expeditious progress.
    As explained above, a determination that listing is warranted but 
precluded also must demonstrate that expeditious progress is being made 
to add or remove qualified species to and from the Lists of Endangered 
and Threatened Wildlife and Plants. (Although we do not discuss it in 
detail here, we also are making expeditious progress in removing 
species from the Lists under the Recovery program, which is funded by a 
separate line item in the budget of the Endangered Species Program. As 
explained above in our description of the statutory cap on Listing 
Program funds, the Recovery Program funds and actions supported by them 
cannot be considered in determining expeditious progress made in the 
Listing Program.) As with our ``precluded'' finding, expeditious 
progress in adding qualified species to the Lists is a function of the 
resources available and the competing demands for those funds. Given 
that limitation, we find that we are making progress in FY 2010 in the 
Listing Program. This progress included preparing and publishing the 
determinations presented in Table 6.

                                    TABLE 6. FY2010 Completed Listing Actions
----------------------------------------------------------------------------------------------------------------
         Publication Date                        Title                     Actions                FR Pages
----------------------------------------------------------------------------------------------------------------
10/08/2009                          Listing Lepidium papilliferum   Final Listing,         74 FR 52013-52064
                                     (Slickspot Peppergrass) as a   Threatened...........
                                    Threatened Species Throughout
                                     Its Range.
----------------------------------------------------------------------------------------------------------------
10/27/2009                          90-day Finding on a Petition    Notice of 90-day       74 FR 55177-55180
                                     To List the American Dipper     Petition Finding,
                                     in the Black Hills of South     Not Substantial
                                     Dakota as Threatened or
                                     Endangered
----------------------------------------------------------------------------------------------------------------
10/28/2009                          Status Review of Arctic         Notice of Intent to    74 FR 55524-55525
                                     Grayling (Thymallus arcticus)   Conduct Status
                                     in the Upper Missouri River     Review
                                     System
----------------------------------------------------------------------------------------------------------------
11/03/2009                          Listing the British Columbia    Proposed Listing       74 FR 56757-56770
                                     Distinct Population Segment     Threatened
                                     of the Queen Charlotte
                                     Goshawk Under the ESA:
                                     Proposed rule.
----------------------------------------------------------------------------------------------------------------
11/03/2009                          Listing the Salmon-Crested      Proposed Listing       74 FR 56770-56791
                                     Cockatoo as Threatened          Threatened
                                     Throughout Its Range with
                                     Special Rule
----------------------------------------------------------------------------------------------------------------
11/23/2009                          Status Review of Gunnison sage- Notice of Intent to    74 FR 61100-61102
                                     grouse (Centrocercus minimus)   Conduct Status
                                                                     Review
----------------------------------------------------------------------------------------------------------------
12/03/2009                          12-Month Finding on a Petition  Notice of 12-month     74 FR 63343-63366
                                     to List the Black-tailed        Petition Finding,
                                     Prairie Dog as Threatened or    Not warranted
                                     Endangered
----------------------------------------------------------------------------------------------------------------
12/03/2009                          90-Day Finding on a Petition    Notice of 90-day       74 FR 63337-63343
                                     to List Sprague's Pipit as      Petition Finding,
                                     Threatened or Endangered        Substantial
----------------------------------------------------------------------------------------------------------------
12/15/2009                          90-Day Finding on Petitions To  Notice of 90-day       74 FR 66260-66271
                                     List 9 Species of Mussels       Petition Finding,
                                     From Texas as Threatened or     Substantial
                                     Endangered With Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
12/16/2009                          Partial 90-Day Finding on a     Notice of 90-day       74 FR 66865-66905
                                     Petition to List 475 Species    Petition Finding,
                                     in the Southwestern United      Not Substantial &
                                     States as Threatened or         Substantial
                                     Endangered With Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
12/17/2009                          12-month Finding on a Petition  Notice of 12-month     74 FR 66937-66950
                                     To Change the Final Listing     Petition Finding,
                                     of the Distinct Population      Warranted but
                                     Segment of the Canada Lynx To   Precluded
                                     Include New Mexico
----------------------------------------------------------------------------------------------------------------
01/05/2010                          Listing Foreign Bird Species    Proposed Listing,      75 FR 605-649
                                     in Peru & Bolivia as            Endangered
                                     Endangered Throughout Their
                                     Range
----------------------------------------------------------------------------------------------------------------

[[Page 54747]]

 
01/05/2010                          Listing Six Foreign Birds as    Proposed Listing,      75 FR 286-310
                                     Endangered Throughout Their     Endangered
                                     Range
----------------------------------------------------------------------------------------------------------------
01/05/2010                          Withdrawal of Proposed Rule to  Proposed rule,         75 FR 310-316
                                     List Cook's Petrel              Withdrawal
----------------------------------------------------------------------------------------------------------------
01/05/2010                          Final Rule to List the          Final Listing,         75 FR 235-250
                                     Galapagos Petrel & Heinroth's   Threatened
                                     Shearwater as Threatened
                                     Throughout Their Ranges
----------------------------------------------------------------------------------------------------------------
01/20/2010                          Initiation of Status Review     Notice of Intent to    75 FR 3190-3191
                                     for Agave eggersiana &          Conduct Status
                                     Solanum conocarpum              Review
----------------------------------------------------------------------------------------------------------------
02/09/2010                          12-month Finding on a Petition  Notice of 12-month     75 FR 6437-6471
                                     to List the American Pika as    Petition Finding,
                                     Threatened or Endangered        Not Warranted
----------------------------------------------------------------------------------------------------------------
02/25/2010                          12-Month Finding on a Petition  Notice of 12-month     75 FR 8601-8621
                                     To List the Sonoran Desert      Petition Finding,
                                    Population of the Bald Eagle     Not Warranted
                                     as a Threatened or Endangered
                                     Distinct Population Segment.
----------------------------------------------------------------------------------------------------------------
02/25/2010                          Withdrawal of Proposed Rule To  Withdrawal of          75 FR 8621-8644
                                     List the Southwestern           Proposed Rule to
                                     Washington/Columbia River       List
                                     Distinct Population Segment
                                     of Coastal Cutthroat Trout
                                     (Oncorhynchus clarki clarki)
                                     as Threatened
----------------------------------------------------------------------------------------------------------------
03/18/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 13068-13071
                                     to List the Berry Cave          Petition Finding,
                                     salamander as Endangered        Substantial
----------------------------------------------------------------------------------------------------------------
03/23/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 13717-13720
                                     to List the Southern            Petition Finding,
                                     Hickorynut Mussel (Obovaria     Not Substantial
                                     jacksoniana) as Endangered or
                                     Threatened
----------------------------------------------------------------------------------------------------------------
03/23/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 13720-13726
                                     to List the Striped Newt as     Petition Finding,
                                     Threatened                      Substantial
----------------------------------------------------------------------------------------------------------------
03/23/2010                          12-Month Findings for           Notice of 12-month     75 FR 13910-14014
                                     Petitions to List the Greater   Petition Finding,
                                     Sage-Grouse (Centrocercus       Warranted but
                                     urophasianus) as Threatened     Precluded
                                     or Endangered
----------------------------------------------------------------------------------------------------------------
03/31/2010                          12-Month Finding on a Petition  Notice of 12-month     75 FR 16050-16065
                                     to List the Tucson Shovel-      Petition Finding,
                                     Nosed Snake (Chionactis         Warranted but
                                     occipitalis klauberi) as        Precluded
                                     Threatened or Endangered with
                                     Critical Habitat
----------------------------------------------------------------------------------------------------------------
04/05/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 17062-17070
                                     To List Thorne's Hairstreak     Petition Finding,
                                     Butterfly as or Endangered      Substantial
----------------------------------------------------------------------------------------------------------------
04/06/2010                          12-month Finding on a Petition  Notice of 12-month     75 FR 17352-17363
                                     To List the Mountain            Petition Finding,
                                     Whitefish in the Big Lost       Not Warranted
                                     River, Idaho, as Endangered
                                     or Threatened
----------------------------------------------------------------------------------------------------------------
04/06/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 17363-17367
                                     to List a Stonefly (Isoperla    Petition Finding,
                                     jewetti) & a Mayfly (Fallceon   Not Substantial
                                     eatoni) as Threatened or
                                     Endangered with Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
04/07/2010                          12-Month Finding on a Petition  Notice of 12-month     75 FR 17667-17680
                                     to Reclassify the Delta Smelt   Petition Finding,
                                     From Threatened to Endangered   Warranted but
                                     Throughout Its Range            Precluded
----------------------------------------------------------------------------------------------------------------
04/13/2010                          Determination of Endangered     Final Listing,         75 FR 18959-19165
                                     Status for 48 Species on        Endangered
                                     Kauai & Designation of
                                     Critical Habitat
----------------------------------------------------------------------------------------------------------------
04/15/2010                          Initiation of Status Review of  Notice of Initiation   75 FR 19591-19592
                                     the North American Wolverine    of Status Review
                                     in the Contiguous United
                                     States
----------------------------------------------------------------------------------------------------------------

[[Page 54748]]

 
04/15/2010                          12-Month Finding on a Petition  Notice of 12-month     75 FR 19592-19607
                                     to List the Wyoming Pocket      Petition Finding,
                                     Gopher as Endangered or         Not Warranted
                                     Threatened with Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
04/16/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 19925-19935
                                     to List a Distinct Population   Petition Finding,
                                     Segment of the Fisher in Its   Substantial..........
                                     United States Northern Rocky
                                     Mountain Range as Endangered
                                     or Threatened with Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
04/20/2010                          Initiation of Status Review     Notice of Initiation   75 FR 20547-20548
                                     for Sacramento splittail        of Status Review
                                     (Pogonichthys macrolepidotus)
----------------------------------------------------------------------------------------------------------------
04/26/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 21568-21571
                                     to List the Harlequin           Petition Finding,
                                     Butterfly as Endangered        Substantial..........
----------------------------------------------------------------------------------------------------------------
04/27/2010                          12-Month Finding on a Petition  Notice of 12-month     75 FR 22012-22025
                                     to List Susan's Purse-making    Petition Finding,
                                     Caddisfly (Ochrotrichia         Not Warranted
                                     susanae) as Threatened or
                                     Endangered
----------------------------------------------------------------------------------------------------------------
04/27/2010                          90-day Finding on a Petition    Notice of 90-day       75 FR 22063-22070
                                     to List the Mohave Ground       Petition Finding,
                                     Squirrel as Endangered with     Substantial
                                     Critical Habitat
----------------------------------------------------------------------------------------------------------------
05/04/2010                          90-Day Finding on a Petition    Notice of 90-day       75 FR 23654-23663
                                     to List Hermes Copper           Petition Finding,
                                     Butterfly as Threatened or      Substantial
                                     Endangered
----------------------------------------------------------------------------------------------------------------
6/1/2010                            90-Day Finding on a Petition    Notice of 90-day       75 FR 30313-30318
                                     To List Castanea pumila var.    Petition Finding,
                                     ozarkensis                      Substantial
----------------------------------------------------------------------------------------------------------------
6/1/2010                            12-month Finding on a Petition  Notice of 12-month     75 FR 30338-30363
                                     to List the White-tailed        petition finding,
                                     Prairie Dog as Endangered or    Not warranted
                                     Threatened
----------------------------------------------------------------------------------------------------------------
6/9/2010                            90-Day Finding on a Petition    Notice of 90-day       75 FR 32728-32734
                                     To List van Rossem's Gull-      Petition Finding,
                                     billed Tern as Endangered       Substantial
                                     orThreatened.
----------------------------------------------------------------------------------------------------------------
6/16/2010                           90-Day Finding on Five          Notice of 90-day       75 FR 34077-34088
                                     Petitions to List Seven         Petition Finding,
                                     Species of Hawaiian Yellow-     Substantial
                                     faced Bees as Endangered
----------------------------------------------------------------------------------------------------------------
6/22/2010                           12-Month Finding on a Petition  Notice of 12-month     75 FR 35398-35424
                                     to List the Least Chub as       petition finding,
                                     Threatened or Endangered        Warranted but
                                                                     precluded
----------------------------------------------------------------------------------------------------------------
6/23/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 35746-35751
                                     to List the Honduran Emerald    Petition Finding,
                                     Hummingbird as Endangered       Substantial
----------------------------------------------------------------------------------------------------------------
6/23/2010                           Listing Ipomopsis polyantha     Proposed Listing       75 FR 35721-35746
                                     (Pagosa Skyrocket) as           Endangered Proposed
                                     Endangered Throughout Its       Listing Threatened
                                     Range, and Listing Penstemon
                                     debilis (Parachute
                                     Beardtongue) and Phacelia
                                     submutica (DeBeque Phacelia)
                                     as Threatened Throughout
                                     Their Range
----------------------------------------------------------------------------------------------------------------
6/24/2010                           Listing the Flying Earwig       Final Listing          75 FR 35990-36012
                                     Hawaiian Damselfly and          Endangered
                                     Pacific Hawaiian Damselfly As
                                     Endangered Throughout Their
                                     Ranges
----------------------------------------------------------------------------------------------------------------
6/24/2010                           Listing the Cumberland Darter,  Proposed Listing       75 FR 36035-36057
                                     Rush Darter, Yellowcheek        Endangered
                                     Darter, Chucky Madtom, and
                                     Laurel Dace as Endangered
                                     Throughout Their Ranges
----------------------------------------------------------------------------------------------------------------
6/29/2010                           Listing the Mountain Plover as  Reinstatement of       75 FR 37353-37358
                                     Threatened                      Proposed Listing
                                                                     Threatened
----------------------------------------------------------------------------------------------------------------
7/20/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 42033-42040
                                     to List Pinus albicaulis        Petition Finding,
                                     (Whitebark Pine) as             Substantial
                                     Endangered or Threatened with
                                     Critical Habitat
----------------------------------------------------------------------------------------------------------------

[[Page 54749]]

 
7/20/2010                           12-Month Finding on a Petition  Notice of 12-month     75 FR 42040-42054
                                     to List the Amargosa Toad as    petition finding,
                                     Threatened or Endangered        Not warranted
----------------------------------------------------------------------------------------------------------------
7/20/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 42059-42066
                                     to List the Giant Palouse       Petition Finding,
                                     Earthworm (Driloleirus          Substantial
                                     americanus) as Threatened or
                                     Endangered
----------------------------------------------------------------------------------------------------------------
7/27/2010                           Determination on Listing the    Final Listing          75 FR 43844-43853
                                     Black-Breasted Puffleg as       Endangered
                                     Endangered Throughout its
                                     Range; Final Rule
----------------------------------------------------------------------------------------------------------------
7/27/2010                           Final Rule to List the Medium   Final Listing          75 FR 43853-43864
                                     Tree-Finch (Camarhynchus        Endangered
                                     pauper) as Endangered
                                     Throughout Its Range
----------------------------------------------------------------------------------------------------------------
8/3/2010                            Determination of Threatened     Final Listing          75 FR 45497- 45527
                                     Status for Five Penguin         Threatened
                                     Species
----------------------------------------------------------------------------------------------------------------
8/4/2010                            90-Day Finding on a Petition    Notice of 90-day       75 FR 46894- 46898
                                     To List the Mexican Gray Wolf   Petition Finding,
                                     as an Endangered Subspecies     Substantial
                                     With Critical Habitat
----------------------------------------------------------------------------------------------------------------
8/10/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 48294-48298
                                     to List Arctostaphylos          Petition Finding,
                                     franciscana as Endangered       Substantial
                                     with Critical Habitat
----------------------------------------------------------------------------------------------------------------
8/17/2010                           Listing Three Foreign Bird      Final Listing          75 FR 50813-50842
                                     Species from Latin America      Endangered
                                     and the Caribbean as
                                     Endangered Throughout Their
                                     Range
----------------------------------------------------------------------------------------------------------------
8/17/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 50739-50742
                                     to List Brian Head              Petition Finding,
                                     Mountainsnail as Endangered     Not substantial
                                     or Threatened with Critical
                                     Habitat
----------------------------------------------------------------------------------------------------------------
8/24/2010                           90-Day Finding on a Petition    Notice of 90-day       75 FR 51969-51974
                                     to List the Oklahoma Grass      Petition Finding,
                                     Pink Orchid as Endangered or    Substantial
                                     Threatened
----------------------------------------------------------------------------------------------------------------

    Our expeditious progress also includes work on listing actions that 
we funded in FY 2010 but have not yet been completed to date (Table 7). 
These actions are listed below. Actions in the top section of the table 
are being conducted under a deadline set by a court. Actions in the 
middle section of the table are being conducted to meet statutory 
timelines, that is, timelines required under the ESA. Actions in the 
bottom section of the table are high-priority listing actions. These 
actions include work primarily on species with an LPN of 2, and 
selection of these species is partially based on available staff 
resources, and when appropriate, include species with a lower priority 
if they overlap geographically or have the same threats as the species 
with the high priority. Including these species together in the same 
proposed rule results in considerable savings in time and funding, as 
compared to preparing separate proposed rules for each of them in the 
future.

        TABLE 7. Actions Funded in FY 2010 But Not Yet Completed
------------------------------------------------------------------------
                 Species                               Action
------------------------------------------------------------------------
           Actions Subject to Court Order/Settlement Agreement
------------------------------------------------------------------------
6 Birds from Eurasia                       Final listing determination
------------------------------------------------------------------------
African penguin                            Final listing determination
------------------------------------------------------------------------
Flat-tailed horned lizard                  Final listing determination
------------------------------------------------------------------------
Mountain plover\4\                         Final listing determination
------------------------------------------------------------------------
6 Birds from Peru                          Proposed listing
                                            determination
------------------------------------------------------------------------
Sacramento splittail                       12-month petition finding
------------------------------------------------------------------------
Pacific walrus                             12-month petition finding
------------------------------------------------------------------------
Gunnison sage-grouse                       12-month petition finding
------------------------------------------------------------------------
Wolverine                                  12-month petition finding
------------------------------------------------------------------------

[[Page 54750]]

 
Arctic grayling                            12-month petition finding
------------------------------------------------------------------------
Agave eggergsiana                          12-month petition finding
------------------------------------------------------------------------
Solanum conocarpum                         12-month petition finding
------------------------------------------------------------------------
Jemez Mountains salamander                 12-month petition finding
------------------------------------------------------------------------
Sprague's pipit                            12-month petition finding
------------------------------------------------------------------------
Desert tortoise - Sonoran population       12-month petition finding
------------------------------------------------------------------------
Pygmy rabbit (rangewide)\1\                12-month petition finding
------------------------------------------------------------------------
Thorne's Hairstreak butterfly\4\           12-month petition finding
------------------------------------------------------------------------
Hermes copper butterfly\4\                 12-month petition finding
------------------------------------------------------------------------
                    Actions with Statutory Deadlines
------------------------------------------------------------------------
Casey's june beetle                        Final listing determination
------------------------------------------------------------------------
Georgia pigtoe, interrupted rocksnail,     Final listing determination
 and rough hornsnail
------------------------------------------------------------------------
7 Bird species from Brazil                 Final listing determination
------------------------------------------------------------------------
Southern rockhopper penguin - Campbell     Final listing determination
 Plateau population
------------------------------------------------------------------------
5 Bird species from Colombia and Ecuador   Final listing determination
------------------------------------------------------------------------
Queen Charlotte goshawk                    Final listing determination
------------------------------------------------------------------------
5 species southeast fish (Cumberland       Final listing determination
 Darter, Rush Darter, Yellowcheek Darter,
 Chucky Madtom, and Laurel Dace)
------------------------------------------------------------------------
 Salmon crested cockatoo                   Proposed listing
                                            determination
------------------------------------------------------------------------
CA golden trout                            12-month petition finding
------------------------------------------------------------------------
Black-footed albatross                     12-month petition finding
------------------------------------------------------------------------
Mount Charleston blue butterfly            12-month petition finding
------------------------------------------------------------------------
Mojave fringe-toed lizard\1\               12-month petition finding
------------------------------------------------------------------------
Kokanee - Lake Sammamish population\1\     12-month petition finding
------------------------------------------------------------------------
Cactus ferruginous pygmy-owl\1\            12-month petition finding
------------------------------------------------------------------------
Northern leopard frog                      12-month petition finding
------------------------------------------------------------------------
Tehachapi slender salamander               12-month petition finding
------------------------------------------------------------------------
Coqui Llanero                              12-month petition finding
------------------------------------------------------------------------
Dusky tree vole                            12-month petition finding
------------------------------------------------------------------------
3 MT invertebrates (mist forestfly(Lednia  12-month petition finding
 tumana), Oreohelix sp.3, Oreohelix sp.
 31) from 206 species petition
------------------------------------------------------------------------
5 UT plants (Astragalus hamiltonii,        12-month petition finding
 Eriogonum soredium, Lepidium ostleri,
 Penstemon flowersii, Trifolium
 friscanum) from 206 species petition
------------------------------------------------------------------------
2 CO plants (Astragalus microcymbus,       12-month petition finding
 Astragalus schmolliae) from 206 species
 petition
------------------------------------------------------------------------
5 WY plants (Abronia ammophila, Agrostis   12-month petition finding
 rossiae, Astragalus proimanthus,
 Boechere (Arabis) pusilla, Penstemon
 gibbensii) from 206 species petition
------------------------------------------------------------------------
Leatherside chub (from 206 species         12-month petition finding
 petition)
------------------------------------------------------------------------

[[Page 54751]]

 
Frigid ambersnail (from 206 species        12-month petition finding
 petition)
------------------------------------------------------------------------
Gopher tortoise - eastern population       12-month petition finding
------------------------------------------------------------------------
Wrights marsh thistle                      12-month petition finding
------------------------------------------------------------------------
67 of 475 southwest species                12-month petition finding
------------------------------------------------------------------------
Grand Canyon scorpion (from 475 species    12-month petition finding
 petition)
------------------------------------------------------------------------
Anacroneuria wipukupa (a stonefly from     12-month petition finding
 475 species petition)
------------------------------------------------------------------------
Rattlesnake-master borer moth (from 475    12-month petition finding
 species petition)
------------------------------------------------------------------------
3 Texas moths (Ursia furtiva,              12-month petition finding
 Sphingicampa blanchardi, Agapema
 galbina) (from 475 species petition)
------------------------------------------------------------------------
2 Texas shiners (Cyprinella sp.,           12-month petition finding
 Cyprinella lepida) (from 475 species
 petition)
------------------------------------------------------------------------
3 South Arizona plants (Erigeron           12-month petition finding
 piscaticus, Astragalus hypoxylus,
 Amoreuxia gonzalezii) (from 475 species
 petition)
------------------------------------------------------------------------
5 Central Texas mussel species (3 from     12-month petition finding
 474 species petition)
------------------------------------------------------------------------
14 parrots (foreign species)               12-month petition finding
------------------------------------------------------------------------
Berry Cave salamander\1\                   12-month petition finding
------------------------------------------------------------------------
Striped Newt\1\                            12-month petition finding
------------------------------------------------------------------------
Fisher - Northern Rocky Mountain Range\1\  12-month petition finding
------------------------------------------------------------------------
Mohave Ground Squirrel\1\                  12-month petition finding
------------------------------------------------------------------------
Puerto Rico Harlequin Butterfly            12-month petition finding
------------------------------------------------------------------------
Western gull-billed tern                   12-month petition finding
------------------------------------------------------------------------
Ozark chinquapin (Castanea pumila var.     12-month petition finding
 ozarkensis)
------------------------------------------------------------------------
HI yellow-faced bees                       12-month petition finding
------------------------------------------------------------------------
Giant Palouse earthworm                    12-month petition finding
------------------------------------------------------------------------
Whitebark pine                             12-month petition finding
------------------------------------------------------------------------
OK grass pink (Calopogon oklahomensis)\1\  12-month petition finding
------------------------------------------------------------------------
Southeastern pop snowy plover & wintering  90-day petition finding
 pop. of piping plover\1\
------------------------------------------------------------------------
Eagle Lake trout\1\                        90-day petition finding
------------------------------------------------------------------------
Smooth-billed ani\1\                       90-day petition finding
------------------------------------------------------------------------
Bay Springs salamander\1\                  90-day petition finding
------------------------------------------------------------------------
32 species of snails and slugs\1\          90-day petition finding
------------------------------------------------------------------------
42 snail species (Nevada & Utah)           90-day petition finding
------------------------------------------------------------------------
Red knot roselaari subspecies              90-day petition finding
------------------------------------------------------------------------
Peary caribou                              90-day petition finding
------------------------------------------------------------------------
Plains bison                               90-day petition finding
------------------------------------------------------------------------
Spring Mountains checkerspot butterfly     90-day petition finding
------------------------------------------------------------------------
Spring pygmy sunfish                       90-day petition finding
------------------------------------------------------------------------
Bay skipper                                90-day petition finding
------------------------------------------------------------------------

[[Page 54752]]

 
Unsilvered fritillary                      90-day petition finding
------------------------------------------------------------------------
Texas kangaroo rat                         90-day petition finding
------------------------------------------------------------------------
Spot-tailed earless lizard                 90-day petition finding
------------------------------------------------------------------------
Eastern small-footed bat                   90-day petition finding
------------------------------------------------------------------------
Northern long-eared bat                    90-day petition finding
------------------------------------------------------------------------
Prairie chub                               90-day petition finding
------------------------------------------------------------------------
10 species of Great Basin butterfly        90-day petition finding
------------------------------------------------------------------------
6 sand dune (scarab) beetles               90-day petition finding
------------------------------------------------------------------------
Golden-winged warbler                      90-day petition finding
------------------------------------------------------------------------
Sand-verbena moth                          90-day petition finding
------------------------------------------------------------------------
404 Southeast species                      90-day petition finding
------------------------------------------------------------------------
                    High Priority Listing Actions\3\
------------------------------------------------------------------------
19 Oahu candidate species\3\ (16 plants,   Proposed listing
 3 damselflies) (15 with LPN = 2, 3 with
 LPN = 3, 1 with LPN =9)
------------------------------------------------------------------------
19 Maui-Nui candidate species\3\ (16       Proposed listing
 plants, 3 tree snails) (14 with LPN = 2,
 2 with LPN = 3, 3 with LPN = 8)
------------------------------------------------------------------------
Dune sagebrush lizard (formerly Sand dune  Proposed listing
 lizard)\3\ (LPN = 2)
------------------------------------------------------------------------
2 Arizona springsnails\3\ (Pyrgulopsis     Proposed listing
 bernadina (LPN = 2), Pyrgulopsis
 trivialis (LPN = 2))
------------------------------------------------------------------------
 New Mexico springsnail\3\ (Pyrgulopsis    Proposed listing
 chupaderae (LPN = 2)
------------------------------------------------------------------------
2 mussels\3\ (rayed bean (LPN = 2),        Proposed listing
 snuffbox No LPN)
------------------------------------------------------------------------
2 mussels\3\ (sheepnose (LPN = 2),         Proposed listing
 spectaclecase (LPN = 4),)
------------------------------------------------------------------------
Ozark hellbender\2\ (LPN = 3)              Proposed listing
------------------------------------------------------------------------
Altamaha spinymussel\3\ (LPN = 2)          Proposed listing
------------------------------------------------------------------------
8 southeast mussels (southern kidneyshell  Proposed listing
 (LPN = 2), round ebonyshell (LPN = 2),
 Alabama pearlshell (LPN = 2), southern
 sandshell (LPN = 5), fuzzy pigtoe (LPN =
 5), Choctaw bean (LPN = 5), narrow
 pigtoe (LPN = 5), and tapered pigtoe
 (LPN = 11))
------------------------------------------------------------------------
\1\ Funds for listing actions for these species were provided in
  previous FYs.
\2\ We funded a proposed rule for this subspecies with an LPN of 3 ahead
  of other species with LPN of 2, because the threats to the species
  were so imminent and of a high magnitude that we considered emergency
  listing if we were unable to fund work on a proposed listing rule in
  FY 2008.
\3\ Although funds for these high-priority listing actions were provided
  in FY 2008 or 2009, due to the complexity of these actions and
  competing priorities, these actions are still being developed.
\4\Partially funded with FY 2010 funds; also will be funded with FY 2011
  funds.

    We have endeavored to make our listing actions as efficient and 
timely as possible, given the requirements of the relevant law and 
regulations, and constraints relating to workload and personnel. We are 
continually considering ways to streamline processes or achieve 
economies of scale, such as by batching related actions together. Given 
our limited budget for implementing section 4 of the ESA, these actions 
described above collectively constitute expeditious progress.
    The upper Missouri River DPS of Arctic grayling will be added to 
the list of candidate species upon publication of this 12-month 
finding. We will continue to monitor the status of this species as new 
information becomes available. This review will determine if a change 
in status is warranted, including the need to make prompt use of 
emergency listing procedures.
    We intend that any proposed listing action for the upper Missouri 
River DPS of Arctic grayling will be as accurate as possible. 
Therefore, we will continue to accept additional information and 
comments from all concerned governmental agencies, the scientific 
community, industry, or any other interested party concerning this 
finding.

References Cited

    A complete list of references cited is available on the Internet at 
http://

[[Page 54753]]

www.regulations.gov and upon request from the Montana Field Office (see 
ADDRESSES section).

Authors

    The primary authors of this notice are the staff members of the 
Montana Field Office.

Authority

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

    Dated: August 30, 2010
Daniel M. Ashe,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2010-22038 Filed 9-7-10; 8:45 am]
BILLING CODE 4310-55-S