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Endangered and Threatened Wildlife and Plants; 90-day Finding on a Petition To List the Redband Trout in the Great Basin as Threatened or Endangered
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: November 16, 1998 (Volume 63, Number 220)]
[Proposed Rules]
[Page 63657-63659]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16no98-31]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 90-day Finding on
a Petition To List the Redband Trout in the Great Basin as Threatened
or Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 90-day petition finding and initiation of status
review.
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SUMMARY: We (the U.S. Fish and Wildlife Service) announce a 90-day
finding for a petition to list the redband trout (Oncorhynchus mykiss
ssp.) in the Great Basin as an endangered or threatened species
throughout its range, pursuant to the Endangered Species Act of 1973
(16 U.S.C. 1531 et seq.), as amended (Act). We find that the petition
presents substantial scientific or commercial information indicating
that listing at the level of the Great Basin population of redband
trout as a whole or at the level of each of the six sub-populations may
be warranted. We are initiating a status review to determine if listing
any or all of the subpopulations is warranted. All further reference in
this notice to redband trout in the Great Basin will identify this fish
as the Great Basin redband trout.
DATES: The finding announced in this document was made on November 6,
1998. To be considered in the 12-month finding for this petition,
information and comments should be submitted to us by January 15, 1999.
ADDRESSES: Information, written comments and materials, or questions
concerning this petition should be submitted to the Supervisor, U.S.
Fish and Wildlife Service, 2600 SE 98th Avenue, Suite 100, Portland,
Oregon 97266. The petition finding, supporting data, and comments are
available for public inspection, by appointment, during normal business
hours at the above address.
FOR FURTHER INFORMATION CONTACT: Antonio Bentivoglio, biologist, at the
above address or telephone 503-231-6179.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(A) of the Endangered Species Act of 1973, as
amended (Act) (16 U.S.C. 1531 et seq.), requires that we make a finding
on whether a petition to list, delist, or reclassify a species,
presents substantial scientific or commercial information to
demonstrate that the petitioned action may be warranted. This finding
is to be based on all information available to us at the time the
finding is made. To the maximum extent practicable, this finding is to
be made within 90 days of receipt of the petition, and the finding is
to be published promptly in the Federal Register. If we find
substantial information present, we are required to promptly commence a
review of the status of the species if one has not already been
initiated under our internal candidate assessment process.
We have made a 90-day finding on a petition to list the Great Basin
redband trout (Oncorhynchus mykiss ssp.). The petition, dated September
4, 1997, was submitted by the Oregon Natural Desert Association, Oregon
Trout, Native Fish Society, and Oregon Council of Trout Unlimited, and
was received by us on September 8, 1997. The petition requests the
listing of the indigenous redband trout in the Great Basin as
endangered or threatened throughout its range in southeastern Oregon,
northeastern California, and northwestern Nevada, in particular the
redband trout populations in Catlow, Fort Rock (Silver Lake), Harney
(Malheur Lake), Goose Lake, Warner, and Chewaucan (Lake Abert/Summer
Lake) basins (together these six closed basins make up the Great Basin
as described in the petition). The petition also requests the
designation of critical habitat concurrent with listing. The letter
clearly identified itself as a petition and contained the names,
signatures, and addresses of the petitioners. Accompanying the petition
was supporting information relating to taxonomy, ecology, threats, and
past and present distribution of the Great Basin redband trout.
The petition, supporting documentation, and other information
available in our files have been reviewed to determine if substantial
information is available to indicate that the requested action may be
warranted. On the basis of the best scientific and commercial
information available, we find the petitioned action may be warranted
for the Great Basin redband trout because of threats to existing
populations and declines in population numbers. A status review will be
commenced in accordance with the final listing priority guidance for
fiscal years 1998 and 1999 (63 FR 25502) published on May 8, 1998.
At the time the petition was received, we were operating under the
final listing priority guidance for fiscal year 1997, published
December 5, 1996 (61 FR 64475), and the extension of that listing
priority guidance published October 23, 1997 (62 FR 55268). The fiscal
year guidance clarified the order in which we would continue to process
the backlog of rulemakings following two related events--(1) the
lifting, on April 26, 1996, of the moratorium on final listings imposed
on April 10, 1995 (Public Law 104-6); and (2) the restoration of
significant funding for listing through passage of the omnibus budget
reconciliation law on April 26, 1996, following severe funding
constraints imposed by a number of continuing resolutions between
November 1995, and April 1996. Based on biological considerations, the
guidance established a ``multi-tiered approach that assigned relative
priorities, on a descending basis, to actions to be carried out under
section 4 of the Act'' (61 FR 64479). The guidance called for giving
highest priority (Tier 1) to handling emergency situations, second
highest priority (Tier 2) to resolving the listing status of the
outstanding proposed listings, third priority (Tier 3) to resolving the
conservation status of candidate species and processing administrative
findings on petitions, and lowest priority (Tier 4) to preparation of
proposed or final critical habitat designations, and processing
delistings and reclassifications from endangered to threatened status.
On November 10, 1997, we notified the petitioners that based on the
listing priority guidance for fiscal year 1997, the processing of their
petition fell under Tier 3. We further indicated that our Oregon State
Office (which was assigned the
[[Page 63658]]
responsibility for processing the petition) would continue to direct
personnel and budget toward accomplishment of ongoing Tier 2 and Tier 3
activities for species judged to be in greater need of the Act's
protection than Great Basin redband trout. As these higher priority
activities were accomplished, and personnel and funds became available
however, we would proceed with the 90-day finding on the petition for
Great Basin redband trout.
On May 8, 1998, final listing priority guidance for fiscal years
1998 and 1999 (63 FR 25502) was published. This new guidance changed
the four tier priority system to a three-tier system. Under the three
tier system, first priority (Tier 1) is completion of emergency
listings for species facing the greatest risk to their well-being.
Second priority (Tier 2) is processing final decisions on pending
proposed listings; processing new proposals to add species to the
lists; processing 90-day and 12-month administrative findings on
petitions to add species to the lists and petitions to delist or
reclassify species; and delisting or downlisting actions on species
that have achieved or are moving toward recovery. Third priority (Tier
3) is processing petitions for critical habitat designations and
preparing proposed and final critical habitat designations. Under this
new guidance, the processing of this petition finding is a Tier 2
action.
Both rainbow trout and redband trout belong in the species
Oncorhynchus mykiss. The generally accepted geographic boundary between
rainbow and redband trout is the crest of the Cascade Mountains. Trout
in the species O. mykiss found east of the crest of the Cascade
Mountains are referred to as interior redband trout and those west of
the crest as coastal rainbow trout. Behnke (1992) clearly includes
Great Basin redband trout as part of the interior redband trout complex
but states that ``their classification is a matter of personal
preference and professional judgment.'' Williams et al. (1989)
recognize three subspecies within the Great Basin redband trout
complex--the Catlow Valley redband trout (O. mykiss ssp.), Goose Lake
redband trout (O. mykiss ssp.) and Warner Valley redband trout (O.
mykiss ssp.), but did not name them using subspecific designation.
Other researchers have stated that although the Great Basin redband
trout have no subspecific designation, any or all of the basins might
contain distinct subspecies (Williams et al. 1989, Behnke 1992, Kowtow
1995).
Although Great Basin redband trout are not officially described as
a subspecies, the petitioners supply supporting information for the
recognition of the Great Basin redband trout as a Distinct Vertebrate
Population Segment (DPS). In accordance with our policy on DPSs, for a
taxon to be considered a DPS, two elements must be considered--
discreteness and significance of the taxon (February 7, 1996; 61 FR
4721). Discreteness refers to the separation of a population segment
from other members of the species based on either (1) physical,
physiological, ecological, or behavioral factors, or (2) international
boundaries that result in significant differences in exploitation
control, habitat management, conservation status, or regulatory
mechanisms. Great Basin redband trout, in each of the six basins, are
physically isolated from each other and are isolated from outside
aquatic influences by the presence of mountain ranges. Because of this,
the redband trout in each of the six basins would be considered
discrete.
Significance refers to the biological and ecological importance or
contribution of a discrete population to the species throughout its
range. Examples of significance include--(1) persistence of a discrete
population segment in a unique or unusual ecological setting; (2)
evidence that loss of a discrete segment would result in a significant
gap in the range of the species; (3) evidence that the discrete
population segment represents the only surviving natural occurrence of
a taxon that may be more abundant elsewhere as an introduced population
outside its historic range; or, (4) evidence that the discrete segment
differs markedly from other populations of the species in genetic
characteristics (61 FR 4721). The petitioners provide the following
justification relating to example (1). Among all Oncorhynchus mykiss,
Great Basin redband trout are the only group that exists in isolated
desert watersheds that have been physically isolated from other
watersheds for thousands of years. Equally important is the fact that
these fish are adapted to harsh, high desert environments characterized
by hot summers, cold winters, large diurnal temperature fluctuations,
drought, intermittent stream flows and alkali waters. The petitioners
provide the following justification relating to example (2). Hatchery
rainbow trout stocked in any of the six basins, do not appear to
survive long enough to reproduce. This appears to be due to the unique
ecologically harsh parameters found in these six basins. If Great Basin
redband trout are lost from these basins there is little likelihood
that hatchery stocked trout would be able to survive in this area, thus
a significant gap in the range of the species would occur. The
petitioners provide the following justification relating to example
(4). Publications by Berg (1987), Phelps et al. (1996), and Currens
(1997) indicate evidence of genetic differences among the populations
of redband trout in the Great Basin. Currens' (1997) allozyme data
appear to indicate that, for the Great Basin redband trout, each
basin's redband trout population is genetically distinct.
For these reasons, we believe that the Great Basin redband trout
should be considered discrete and significant. Whether all six basins
are one DPS or six separate DPSs has yet to be determined, and would be
a focal issue of the status review.
In most basins, interior redband trout have adfluvial life
histories, migrating between highly productive rearing areas in lakes
with adjacent marshes and spawning areas in streams, or between
productive marshes and streams. Marshes and lakes provide connections
among various stream populations. During drought episodes that cause
complete desiccation of the lakes and marshes, streams provided refuges
for populations that return to the lakes when they refill (Kowtow
1995). Great Basin redband trout abundance is generally correlated with
healthy riparian vegetation, presence of undercut banks, large woody
debris and general stream habitat complexity. In-stream habitat varies
from higher gradient channels to lakes and marshes with spawning
occurring in loose gravel and well-oxygenated water. Water temperatures
should not exceed 21 degrees Celsius and those above 26.6 degrees
Celsius can be lethal. The smaller stream-resident redband are
generally insectivorous while larger lake-resident fishes eat insects
and small fishes (Kunkel 1976, Lee 1997, Bowers et al. 1979, Charlon et
al 1970).
The petition contains a substantial amount of information relating
to the decline of Great Basin redband trout. The petitioners assert
that the Great Basin redband trout has evolved in and is therefore
adapted to the harsh Great Basin environment. However, human impacts
have decreased suitable habitat, which has led to the decline of Great
Basin redband trout. Although exact historic distribution is unclear,
the petitioners cite references stating that declines have occurred
(Kowtow 1995, Dambacher and Stevens 1996, Bowers and Perkins 1996, Lee
et al. 1997).
The petitioners indicate that declines in Great Basin redband trout
have been most strongly associated with the destruction, modification,
and
[[Page 63659]]
curtailment of this trout's aquatic habitat and range through
degradation of riparian and stream habitat. The petition provides
information regarding effects of habitat degradation and its
relationship to Great Basin redband trout. The petitioners indicate
that habitat degradation from improper livestock grazing practices,
irrigation, stream channel manipulation, and timber harvest affects
redband trout by increasing erosion of banks, increasing sedimentation,
reducing stream bottom complexity, widening and shallowing of the
stream cross section, increasing stream temperature, reducing
streamside vegetation, fragmenting populations, dewatering streams,
reducing watertables, and reducing the amount of large woody debris
(Fleichner 1994, Bowers et al. 1979, Lee et al. 1997, USDA 1996). The
petitioners present the effects of such degradation for each individual
basin and as widespread occurrences in the Great Basin.
The petitioners provide evidence that introgression and competition
by introduced fishes are threats to the continued existence of Great
Basin redband trout. Introgression (i.e., introduction of a gene from
one gene complex into another) resulting from Great Basin redband trout
interbreeding with stocked hatchery rainbows reduces the native redband
offspring's ability to survive harsh Great Basin conditions; introduced
non-native fishes (both hatchery rainbows and exotic species like brook
trout, carp, bass, catfish and crappie) compete with native redband for
resources and can degrade the habitat (Hosford and Pribyl 1983, Kowtow
1995, Lee et al. 1997).
The petitioners also assert that threats to Great Basin redband
trout remain because of the inadequacy of existing regulations.
Emergency fishing regulations, conservation/protective designations by
government agencies and professional societies, water quality
protection measures, and other current and planned conservation
measures have failed to stop the decline of Great Basin redband trout.
We reviewed the petition, as well as other available information,
published and unpublished studies and reports, and agency files. On the
basis of the best scientific and commercial information available, we
find that there is sufficient information to indicate that listing of
the Great Basin redband trout as threatened or endangered, throughout
all or parts of its range, may be warranted. The petitioners also
requested that critical habitat be designated for this species.
Designation of critical habitat is not petitionable under the Act.
However, if the 12-month finding determines that the petitioned action
to list the Great Basin redband trout is warranted, then the
designation of critical habitat would be addressed in the subsequent
proposed rule.
Information Solicited
When we make a finding that substantial information exists to
indicate that listing a species may be warranted, we are also required
to promptly commence a review of the status of the species. To ensure
that the status review is complete and based on the best available
scientific and commercial data, we are soliciting information
concerning the following--(1) information on historic distribution and
information on current distribution in each basin; (2) habitat
conditions in each basin; (3) basic biology including age-frequency
distribution of the population(s) in each basin; (4) ongoing efforts to
protect Great Basin redband trout and their habitat; (5) threats to the
species and its habitat; (6) any information regarding distinct
vertebrate population segment status of Great Basin redband trout as
one unit or as six individual units; and (7) metapopulation dynamics
and interactions between lake and stream morph fishes. In addition to
information pertaining to the Great Basin redband trout, we are
requesting any information in categories 1-7, above, that relates to
Interior redband trout. ``Interior redband trout'' is a common term
referring to any rainbow/redband type trout found east of the crest of
the Cascade Mountains.
References Cited
A complete list of all references cited herein is available on
request from the Oregon State Office (See ADDRESSES section).
Author
The primary author of this document is Antonio Bentivoglio,
biologist, Oregon State Office, U.S. Fish and Wildlife Service (see
ADDRESSES section).
Authority
The authority for this action is the Endangered Species Act of 1973
as amended (16 U.S.C. 1531 et seq.).
Dated: November 6, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 98-30541 Filed 11-13-98; 8:45 am]
BILLING CODE 4310-55-P