[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]
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