[Federal Register Volume 59, Number 141 (Monday, July 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18048]


[[Page Unknown]]

[Federal Register: July 25, 1994]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

 

Endangered and Threatened Wildlife and Plants; Finding on a 
Petition To List the Fluvial Population of the Arctic Grayling as 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) announces a 12-
month finding for a petition to add the fluvial population of the 
Arctic grayling (Thymallus arcticus) to the List of Threatened and 
Endangered Wildlife and Plants. The Service finds that listing the 
fluvial population of the Arctic grayling is warranted but precluded by 
other higher priority listing actions.

DATES: The finding announced in this notice was made on July 18, 1994. 
Comments and information may be submitted until further notice.

ADDRESSES: Information, comments, or questions concerning this finding 
may be submitted to the Field Supervisor, U.S. Fish and Wildlife 
Service, Montana Field Office, 100 N. Park Avenue, Suite 320, Helena, 
Montana 59601. The petition, 90-day finding, 12-month finding, and 
supporting data are available for public inspection, by appointment, 
during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT:
Dale Harms, Assistant Field Supervisor, at the above address, telephone 
(406) 449-5225.

SUPPLEMENTARY INFORMATION: 

Background

    Section 4(b)(3)(B) of the Endangered Species Act (Act) of 1973, as 
amended (16 U.S.C. 1531 et seq.), requires that for any petition to 
revise the Lists of Endangered and Threatened Wildlife and Plants, a 
finding be made within 12 months of the date of receipt of the petition 
on whether the petitioned action is (i) not warranted, (ii) warranted, 
or (iii) warranted but precluded by the efforts to revise the lists and 
expeditious progress is being made in listing and delisting species. 
Notice of the finding is to be published promptly it the Federal 
Register. This notice meets the latter requirement for the 12-month 
finding made earlier for the petition discussed below. Information 
contained in this notice is a summary of the information in the 12-
month finding, which is the Fish and Wildlife Service's (Service) 
decision document.
    A petition dated October 2, 1991, was received by the Service from 
the Biodiversity Legal Foundation and George Wuerthner on October 9, 
1991. The petition request that the ``fluvial Arctic grayling'' be 
listed as an endangered species throughout its historic range in the 
conterminous United States. Additionally, the petitioners requested 
that critical habitat be designated. The petitioners stated that the 
decline of the Fluvial Arctic grayling is a result of many factors. The 
primary causes cited by the petitioners were habitat degradation as a 
result of the effects of domestic livestock grazing and stream 
diversions for irrigation, competition with nonnative trout species, 
and past overharvesting by anglers. Additionally, the petition stated 
that much of the annual recruitment is lost in irrigation ditches.
    Notice of a 90-day finding published in the January 19, 1993, 
Federal Register (58 FR 4975) found that the petitioners provided 
substantial information indicating that listing the fluvial population 
of the Arctic grayling of the upper Missouri River, in Montana and 
northwestern Wyoming, may be warranted. The notice also indicated that 
the Fluvial Arctic grayling population in Michigan is extinct, thus 
there was not substantial information to indicate that listing that 
population may be warranted. Concurrent with publishing notice of the 
90-day finding in the Federal Register, the Service initiated a status 
review.
    All Arctic grayling in North America belong to a single species, 
Thymallus arcticus (family Salmonidae). Within North America, Arctic 
grayling are distributed throughout Alaska and across Canada to the 
Hudson Bay. Additionally, two geographically isolated populations of 
Arctic grayling occurred outside of Canada and Alaska in the contiguous 
United States, apparently as glacial relicts (Vincent 1962). One of 
these populations was found in Michigan and the other in the drainage 
of the upper Missouri River in Montana and extreme northwestern Wyoming 
(Scott and Crossman 1973). The upper Missouri River drainage population 
was the subject of the Service's finding.
    The validity of subspecific distinctions for Arctic grayling has 
not been proven (Scott and Crossman 1973). A status review was first 
initiated for the ``Montana Arctic grayling'' (T. a. montanus), as the 
fluvial Arctic grayling of the upper Missouri River is sometimes known, 
by a notice of review published December 30, 1982 (47 FR 58454). 
However, this subspecific designation is not widely accepted (Kaya 
1990).
    The native Arctic grayling populations of the upper Missouri River 
were predominantly fluvial (Vincent 1962). Fluvial fishes are those 
that are permanently stream-dwelling. Adfluvial (also described as 
lacustrine) fish are those that spend most of their lives in lakes 
except that they spawn in streams. The only indigenous adfluvial Arctic 
grayling in the upper Missouri River basin are thought to be those in 
Red Rock Lakes and, perhaps, Elk Lake (Vincent 1962, Kaya 1990).
    Because fluvial Arctic grayling are adapted to life-long residency 
in stream environments, they are believed to be behaviorally distinct 
from adfluvial grayling. The adfluvial Arctic grayling was not under 
consideration in the Service's finding as it is believed to be a 
distinct population from the fluvial Arctic grayling.
    Historically, in the upper Missouri River drainage the fluvial 
Arctic grayling was widely but irregularly distributed and locally 
abundant above the Great Falls in Montana. Varley and Schullery (1983) 
estimate that Arctic grayling of the upper Missouri River drainage 
presently occur in 8 percent or less of their historic range. Kaya 
(1992) estimates that the remaining upper Missouri distribution of 
fluvial Arctic grayling in 80 to 130 km (50 to 80 miles) of the upper 
Big Hole River may represent 4 to 5 percent of the historic range of 
fluvial Arctic grayling in Montana. Kaya (1992) arrived at this 
estimate by using available information to conclude that, historically, 
grayling may have inhabited approximately 2,000 km (1,250 miles) of 
streams in the upper Missouri River basin until early in this century.
    The only confirmed, self-sustaining remnant of the indigenous upper 
Missouri River fluvial Arctic grayling population exists in the Big 
Hole River and the lower reaches of its tributaries in Beaverhead, Deer 
Lodge, and Silver Bow Counties in Montana (Liknes and Gould 1987, 
Shepard and Oswald 1989, Kaya 1990, Kaya 1992). Fluvial Arctic grayling 
are concentrated in the upper Big Hole River above the Divide dam, 
although they have been documented down to the mouth (Liknes and Gould 
1987, Shepard and Oswald 1989). The numbers of grayling in the Big Hole 
River have been in decline; recent estimates for a section of the Big 
Hole with the highest grayling densities were 69 grayling per km (111 
per mile) in 1983, decreasing to 14 per km (22 per mile) in 1989. The 
population appears to have stabilized in the past 3 years at 
approximately 20 grayling per km (32 per mile) (Kaya 1990; Byorth 1991, 
1993).
    An additional remnant of the fluvial Arctic grayling population of 
the upper Missouri River drainage may occur in and around Ennis 
Reservoir on the Madison River in Madison County, Montana. Until the 
Service receives conclusive information to the contrary, the Arctic 
grayling of Ennis Reservoir/Madison River will be considered a remnant 
of the upper Missouri River fluvial Arctic grayling population.
    A factor complicating identification of the upper Missouri River 
fluvial Arctic grayling population is the extensive hatchery 
propagation and transplantation of Arctic grayling stocks that has 
occurred in lakes and rivers throughout Montana and elsewhere (Lee et 
al. 1980, Everett 1986). The Service does not regard the introduced, 
lake-dwelling graying to be part of the indigenous upper Missouri River 
fluvial Arctic grayling population.
    Introduced Arctic grayling that display partially fluvial 
characteristics reside in Sunnyslope Irrigation Canal in Teton County, 
Montana. The Service does not consider the Sunnyslope Canal Arctic 
grayling to be a remnant of the native upper Missouri River fluvial 
Arctic grayling population.

Summary of Factors Affecting the Species

    The following information is a summary and discussion of the five 
factors or listing criteria as set forth in Section 4(a)(1) of the 
Endangered Species Act (16 U.S.C. 1531 et seq.) and regulations (50 CFR 
Part 424) promulgated to implement the listing provisions of the Act 
and their applicability to the current status of the fluvial population 
of the Arctic grayling.

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

    A substantial portion of the historic range of the fluvial Arctic 
grayling has been altered by the extensive construction of dams and 
reservoirs that have created barriers obstructing migrations to 
spawning, wintering or feeding areas; inundating grayling habitat; and 
altering the hydrology of river systems (Vincent 1962, Kaya 1990). In 
the upper Missouri River drainage, the dominant land use has become 
agriculture-related (Vincent 1962). The major impact from these 
activities on Arctic grayling habitat is by the diversion of water for 
irrigation, which reduces available instream habitat for grayling. This 
results in stranding of incubating eggs or young fish, thus increasing 
predation on young because they are concentrated in the remaining 
water, reducing food availability, increasing water temperatures (Kaya 
1990), decreasing survival of young grayling (Shepard and Oswald 1989), 
and increasing mortality of trapped fish when diversions are shut down 
(Shepard and Oswald 1989, Streu 1990). Increased sedimentation from 
agricultural run-off is also a problem (Vincent 1962, Montana 
Department of Fish, Wildlife and Parks 1989, Shepard and Oswald 1989).

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

    Since Arctic grayling are easily caught by anglers, historical 
exploitation likely contributed to past declines or local extirpations 
of the grayling population in the upper Missouri River drainage 
(Vincent 1962, Kaya 1990). A commercial fishery for Arctic grayling 
existed on the upper Missouri River (Vincent 1962). Catch-and-release 
fishing regulations are currently in effect on the Big Hole in order to 
reduce mortality from recreational fishing (Montana Department of Fish, 
Wildlife and Parks 1989).

C. Disease or Predation

    Although data has been inconclusive, Arctic grayling interactions, 
including competition and predation, with nonnative trout species are 
thought to be factors contributing to the decline of Arctic grayling 
(Vincent 1962, Kaya 1990, 1992).

D. The Inadequacy of Existing Regulatory Mechanisms

    Most of the Big Hole River is managed to produce abundant, large, 
nonnative trout (Montana Department of Fish, Wildlife and Parks 1989). 
Other than catch and release regulations, grayling are a management 
priority only in the one reach in which they are concentrated.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    Vincent (1962) suggested that a gradual climatic change could have 
been a factor in the decline of Arctic grayling populations. Since the 
latter part of the 1980's, drought conditions have been prevalent 
throughout the upper Missouri River drainage. During this same period, 
densities of Arctic grayling and other fishes in the Big Hole River 
have declined (Oswald 1990; Byorth 1991; C. Hunter, Montana Department 
of Fish, Wildlife and Parks, in litt., 1992). Drought exacerbates the 
impacts of others factors affecting Arctic grayling. Decreased fish 
population densities appear to be a natural response to low water flows 
which restrict the amount of fish habitat that is available, 
particularly during critical spawning and rearing periods (C. Hunter, 
in litt., 1992).

Finding

    The Act requires the Service to make determinations regarding 
listing solely on the basis of the best scientific and commercial data 
available after conducting a review of the status of the species and 
after taking into account those efforts being made by States and others 
to protect the species. Additionally, the Act allows the Service to 
list distinct population segments of vertebrate fish and wildlife as 
threatened or endangered. The fluvial form of the Arctic grayling in 
the upper Missouri River drainage is geographically isolated from other 
fluvial grayling populations and is behaviorally distinct from 
adfluvial grayling. For these reasons, the Service believes the fluvial 
form of the Arctic grayling in the upper Missouri River drainage is a 
distinct population segment.
    As discussed above, the fluvial Arctic grayling faces threats 
primarily from a reduction in historical range, decrease in available 
habitat as a result of dewatering within streams, potential competition 
or predation by nonnative fish, and habitat degradation. The Service 
finds that listing of the fluvial population of the Arctic grayling is 
warranted but precluded by work on other species having a higher 
priority for listing.
    Section 4(b) of the Act states that petitioned actions may be found 
to be warranted but precluded by other listing actions when it is found 
that the Service is making expeditious progress in revising the lists. 
Expeditious progress in listing endangered and threatened species is 
being made and is reported annually in the Federal Register. 
Furthermore, on September 21, 1983, (48 FR 43098), the Service 
published a system for prioritizing species for listing. This system 
considers 3 factors in assigning species numerical listing priorities 
on a scale of 1 to 12 (with number 1 as the highest priority). The 
three factors are magnitude of threat, immediacy of threat, and 
taxonomic distinctiveness. Earlier the service had assigned a listing 
priority of 3 to the fluvial Arctic grayling because the Service 
considered the magnitude of threat to be high, the immediacy of threat 
to be imminent, and the taxonomic distinctiveness to be a vertebrate 
population. The Service is now changing the magnitude of threat to 
moderate, primarily as a result of the cooperative efforts that have 
been initiated among private organizations and individuals, 
universities, and State and Federal Agencies to restore the fluvial 
Arctic grayling population in the upper Missouri River drainage (C. 
Hunter, in litt., 1993). Changing the magnitude of threat to moderate 
results in a change of the listing priority from 3 to 9. The 
cooperative efforts include, but are not limited to, the efforts 
discussed below.
    The Service is a member of the Workgroup (Workgroup) and a party to 
a Memorandum of Understanding entered into in 1991 with Federal, State, 
and private entities whose purpose is to conserve and restore fluvial 
Arctic grayling. The Workgroup is near completion of a final 
restoration plan for the fluvial Arctic grayling of the upper Missouri 
River.
    The Montana Department of Fish, Wildlife and Parks and the U.S. 
Forest Service have begun working with landowners to reduce water and 
habitat-related threats to the population. Since 1992, irrigators in 
the Big Hole have voluntarily reduced their water withdrawals in order 
to sustain flows in the river system. Many water users have modified 
their diversions to reduce the incidence of grayling becoming entrapped 
in ditches.
    The Montana Department of Fish, Wildlife and Parks has intensified 
its annual monitoring of the Big Hole River grayling population since 
1991. Recent habitat improvement projects have taken place on the Big 
Hole with the cooperation and assistance of private landowners. In 
1992, a channel of the Big Hole River was reopened, restoring 
substantial historical grayling habitat. Fishing regulations have been 
introduced to protect grayling from harvest. Results from a hooking 
mortality study conducted in 1992 and 1993 indicate that mortality of 
released grayling is low. Field research, begun in 1993, is underway to 
clarify the threat of nonnative fish to fluvial grayling.
    In order to better understand grayling habitat requirements, the 
U.S. Geological Survey collected physical, chemical, and biological 
measurements in segments of the Big Hole River in 1993. The results are 
now being finalized. The Service's Fish Technology Center (Center) in 
Bozeman, Montana, completed a study in 1993 to identify water 
temperatures that may be limiting for grayling.
    Since 1989, the Center has managed and maintained fluvial grayling 
broodstock. Protocols have been established for the development and use 
of a genetic reserve of Big Hole River grayling. The development of 
this genetic reserve is an integral component in fluvial grayling 
restoration because this stock will be used for the reestablishment of 
grayling in other drainages and will provide a ``safety net'' in case 
of a catastrophic loss of fluvial grayling in the Big Hole River.
    In 1992, sites within the upper Missouri River drainage were 
evaluated to identify those with the best potential for successful 
fluvial grayling reestablishment. Progeny of Arctic grayling from the 
Big Hole River were reintroduced into three rivers within their 
historic range and additional reintroductions are planned to 
reestablish viable stocks.
    After reviewing the petition, accompanying documents, research 
findings, and literature cited; the Service concludes that the petition 
requesting that the fluvial population of the Arctic grayling be listed 
as an endangered species is warranted but precluded by other higher 
priority listing actions. After arriving at the warranted but precluded 
finding, the Service recommended that the fluvial Arctic grayling be 
given a listing priority of 9 because the magnitude of threats have 
been moderated as a result of ongoing cooperative conservation actions. 
The petitioners also requested that critical habitat be designated. In 
the future if the warranted but precluded finding for the fluvial 
population of Arctic grayling in the upper Missouri River drainage is 
changed to warranted, then the designation of critical habitat would be 
addressed in the subsequent proposed rule.
    The Service's 12-month finding contains more detailed information 
regarding the above decisions, A copy may be obtained from the Montana 
Field Office (see ADDRESSES section).

References Cited

    A complete list of references cited in this rule is available upon 
request from the Montana Field Office (see ADDRESSES section).

Author

    This notice was prepared by Lori H. Nordstrom (see ADDRESSES 
section).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531-1544).

List of Subjects in 50 CFR Part 17

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

    Dated: July 18,1994.
Mollie H. Beattie,
Director, Fish and Wildlife Service.
[FR Doc. 94-18048 Filed 7-22-94; 8:45 am]
BILLING CODE 4310-55-M