[Federal Register Volume 63, Number 220 (Monday, November 16, 1998)]
[Proposed Rules]
[Pages 63657-63659]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30541]


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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

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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