[Federal Register Volume 69, Number 76 (Tuesday, April 20, 2004)]
[Notices]
[Pages 21151-21158]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-8633]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition To List the Colorado River Cutthroat Trout
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 90-day petition finding.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding for a petition to list the Colorado River cutthroat
trout (CRCT) (Oncorhynchus clarki pleuriticus) as threatened or
endangered under the Endangered Species Act of 1973, as amended. We
find the petition and additional information available in our files did
not present substantial scientific or commercial information indicating
that listing this subspecies may be warranted. We will not be
initiating a further status review in response to this petition. We ask
the public to submit to us any new information that becomes available
concerning the status of or threats to the species. This information
will help us monitor and encourage the conservation of this species.
DATES: The finding announced in this document was made on April 8,
2004. You may submit new information concerning this species for our
consideration at any time.
ADDRESSES: Information, data, or comments concerning this finding
should be submitted to the Assistant Field Supervisor, Ecological
Services, U.S. Fish and Wildlife Service, 764 Horizon Drive, Building
B, Grand Junction, Colorado 81506, or by e-mail to [email protected]
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: Patty Schrader Gelatt, at the above
address, by telephone at 970-243-2778, or by e-mail at patty--
[email protected]
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(A) of the Endangered Species Act of 1973, as
amended (16 U.S.C. 1531 et seq.) (ESA), requires that within 90 days of
receipt of a petition, to the maximum extent practicable, we make a
finding on whether a petition to list, delist, or reclassify a species
presents substantial scientific or commercial information indicating
that the requested action may be warranted. The term ``species''
includes any subspecies of fish or wildlife or plants, and any distinct
population segment of any species of vertebrate fish or wildlife that
interbreeds when mature. The finding is based upon all information
provided or referenced in the petition and all other information
available to us at the time the finding was made. To the maximum extant
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 (50
CFR 424.14). ``Substantial information'' is defined in 50 CFR 424.14(b)
as ``that amount of information that would lead a reasonable person to
believe that the measure proposed in the petition may be warranted.''
On December 16, 1999, we received a formal petition to list the
CRCT as threatened or endangered in its occupied habitat within its
known historic range, in accordance with provisions in section 4 of the
ESA. The petition was filed by the Center for Biological Diversity, the
Biodiversity Legal Foundation, Biodiversity Associates, Ancient Forest
Rescue, Southwest Trout, Wild Utah Forest Campaign, Colorado Wild, and
Mr. Noah Greenwald.
On January 12, 2000, we notified the petitioners that our Listing
Priority Guidance, published in the Federal Register (64 FR 57114) on
October 22, 1999, designated the processing of new listing petitions as
a ``Priority 4'' activity, a lower priority than emergency listing
(Priority 1), processing final decisions on proposed listings (Priority
2), and resolving the status of candidate species (Priority 3). We also
informed the petitioners that due to staff and budget limitations, the
petition could not be immediately addressed.
On August 8, 2000, we received a notice of intent to sue from the
Center for Biological Diversity, Biodiversity Associates, Biodiversity
Legal Foundation, Colorado Wild, Wild Utah Forest Campaign, and Mr.
Noah Greenwald concerning our failure to produce a 90-day finding on
the subject petition in accordance with the provisions of section 4 of
the ESA. We responded on August 31, 2000, reiterating that we would not
be able to begin an evaluation of the CRCT petition until the work on
the higher priority activities was completed. In the spring of 2003,
the Service determined appropriate funds were available to address the
subject petition.
In addition, the Service received correspondence from Mr. Noah
Greenwald on September 20, 2002, providing additional information.
The September 20, 2002, correspondence from the petitioners
recognized that some of the information presented in the original
petition is outdated due to the passage of time. The petitioners
discussed information provided by the states focusing on three specific
issues--hybridization, competition, and predation from nonnatives;
habitat degradation; and inadequacy of existing regulation. The
petitioners again asserted that the range
[[Page 21152]]
of the CRCT has been reduced to a small fraction of its historic range,
resulting in small isolated populations. They also stated that none of
the populations can be considered secure because every one is
threatened by nonnatives, limited stream length, small population size,
habitat limitations, or a combination of these factors. The petitioners
asserted that most CRCT populations are either hybridized or sympatric
with nonnative trout species despite efforts to construct barriers and
remove nonnatives. In addition, the States stock nonnative trout in
CRCT historic range, which limits potential streams where CRCT can be
recovered. The petitioners recommended that we use the same criteria to
evaluate the status of the Colorado River cutthroat trout as was used
for the Rio Grande cutthroat trout (Onchorhynchus clarki virginalis)
candidate status review. The Service did not use these criteria in this
90-day finding because it does not constitute a status review under the
ESA.
Biology and Distribution
The CRCT is the only salmonid (i.e., salmon, trout, and their close
relatives) native to the upper Colorado River basin, and is 1 of 14
subspecies of cutthroat trout recognized by Behnke (1992, 2002) that
are native to interior regions of western North America. It has red or
orange slash marks on both sides of the lower jaws and relatively large
spots concentrated on the posterior part of the body. Sexually mature
males exhibit brilliant colors; the ventral region can be bright
crimson, with red along the lateral line, and the lower sides of the
body are typically golden yellow (Behnke 1992).
The CRCT historically occupied portions of the Colorado River
drainage in Wyoming, Colorado, Utah, Arizona, and New Mexico (Behnke
1992). Its original distribution probably included portions of larger
streams, such as the Green, Yampa, White, Colorado, and San Juan
Rivers. Behnke and Zarn (1976) suggested this subspecies was absent
from the lower reaches of many large rivers because of summer thermal
barriers. The CRCT still occurs throughout its historic range, but
remaining populations now occur mostly in headwater streams and lakes.
The CRCT spawn over a gravel substrate in spring when water
temperatures reach 7[deg]C (45[deg]F). The female digs out a nest in
flowing water and, after fertilization, the eggs are covered with
gravel and hatch in the summer (Behnke and Benson 1980). The CRCT feed
on a wide range of invertebrates; larger CRCT prey on other fishes
(Behnke and Benson 1980).
The States of Colorado, Utah, and Wyoming have implemented
conservation efforts for CRCT for many years. Each State has developed
plans to facilitate conservation action for CRCT within their
respective States (Wyoming Game and Fish Department (WGFD) 1987;
Colorado Division of Wildlife (CDOW) 1992; Langlois et al. 1994; Utah
Division of Wildlife Resources (UDWR) 1997). The three States, U.S.
Forest Service (USFS), Bureau of Land Management (BLM), National Park
Service, Ute Indian Tribe, and the Service formed a task force to
address conservation efforts for CRCT on a rangewide basis. A
Conservation Agreement and Strategy (CAS) (CRCT Task Force 1999, 2001)
was developed to expedite implementation of conservation measures for
the CRCT in Colorado, Utah, and Wyoming as a collaborative and
cooperative effort among resource agencies. The primary goal of the CAS
is to assure the long-term prosperity of CRCT throughout their historic
range by establishing two self-sustaining metapopulations, each
consisting of five separate, viable but interconnected subpopulations,
in each geographic management unit within the historic range. The
short-term goal is to establish one metapopulation in each geographic
management unit. Additional goals of the CAS are to maintain areas that
currently support abundant CRCT and manage other areas for increased
abundance; to maintain the genetic diversity of the subspecies; and to
increase the distribution of CRCT where ecologically and economically
feasible. The specific objective of the CAS is to maintain and restore
383 conservation populations in 2,823 stream kilometers (km) (1,754
stream miles (mi)) and 18 populations in 264 lake hectares (ha) (652
lake acres (ac)) in 14 geographic management units within the historic
range.
The CAS (CRCT Task Force 2001) classifies CRCT populations
according to their genetic purity using the criteria established in
``Cutthroat Trout Management-- a Position Paper. Genetic Considerations
Associated with Cutthroat Trout Management'' (UDWR 2000). This position
paper was developed by fishery administrators and biologists from the
following agencies--Idaho Department of Fish and Game; Montana Fish,
Wildlife and Parks; Nevada Division of Wildlife; New Mexico Game and
Fish; UDWR; WGFD; the Service; USFS; and other technical experts. The
Position Paper defines a ``core conservation population'' as a
population that is 99 percent pure and represents the
historic genome of the native cutthroat trout. Core conservation
populations contain cutthroat trout that have not been impacted by
genetic alteration linked to human intervention. A ``conservation
population'' is defined as a reproducing and recruiting population of
native cutthroat trout that has managed to preserve the historical
genome and/or unique genetic, ecological, and/or behavioral
characteristics. In general, a conservation population is at least 90
percent pure CRCT, but purity may be lower depending on circumstances
and the values and attributes to be preserved.
The CAS established a CRCT Coordination Team to periodically update
the population status information provided in the appendices. As of
July 16, 2003, the States of Colorado, Utah, and Wyoming reported 327
conservation populations, which include 286 populations in
approximately 1,625 stream km (1,010 stream mi) and 41 populations in
approximately 455 ha (1,124 ac) of lakes (CRCT Coordination Team,
unpublished data). These populations include 221 populations that meet
the Coordination Team's definition of core conservation populations. Of
these 221 core conservation populations, 191 are found in approximately
1,101 km (684 mi) of streams and 30 are found in approximately 221 ha
(545 ac) of lakes.
Since 1998, 125 stream populations and 29 lake populations have
been added to the list of conservation populations (including core
conservation populations and conservation populations) (CRCT
Coordination Team, unpublished data). Most of the additions to the list
of conservation populations are due to results of genetic testing that
indicated genetic purity of at least 90 percent. Some waters were
removed from the list due to the results of genetic testing. Other
waters were added after reclamation and restocking were completed.
Still other stream segments were removed because CRCT were extirpated
due to competition from nonnative trout.
Assessment of the Petition and Other Available Information
The 1999 petition and subsequent 2002 letter provided information
regarding the status and threats to CRCT. Soon after we received the
petition, we made the document available on our web site. We also
contacted natural resource agencies whose responsibilities include CRCT
management and requested that these agencies review the petition and
provide information on the current
[[Page 21153]]
status of the subspecies. In response to our request, we received
information from UDWR, WGFD, CDOW, USFS, National Park Service, and
BLM. We reviewed the information provided by these agencies, scientific
journal articles, agency reports, and other information in our files to
determine whether the information provided or cited in the petition or
other information readily available to us met the ESA's standard for
``substantial information.'' We respond to each of the major assertions
made in the petition, organized by ESA listing factors. This 90-day
finding is not a status assessment and does not constitute a status
review under the ESA.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
With respect to factor A, the petition asserted that the CRCT has
been reduced to small, unstable headwater drainages in less than 5
percent of its historic range and that this reduction in range is due
to livestock grazing, water diversions, mining, logging, and roads. The
petition presented an analysis of the reduction of historic range
primarily based on information in a USFS Report (Young et al. 1996).
While we consider this report a source of reliable information, it was
based on a questionnaire distributed to various agency biologists and
not all biologists responded. Therefore, Young et al. (1996) considered
the data base presented as incomplete. The information contained in
this report gave a general overview of the decline of the subspecies,
but did not contain adequate information on the subspecies' status
throughout its current or historical range to determine reduction in
historic range. In fact, Young et al. (1996) stated, ``comprehensive
descriptions of the historical range of the CRCT are unavailable.''
However, for years, scientists have recognized that the current range
of the CRCT has been greatly reduced from its historic range (Behnke
and Zarn 1976; Binns 1977; Behnke and Benson 1980; Martinez 1988; CRCT
Task Force 2001), and we concur with the conclusion that the range of
the CRCT has been greatly reduced from historic levels. The ESA does
not indicate threshold levels of historic range at which listing as
either threatened or endangered becomes warranted. Instead the
principal considerations in determining whether a species warrants
listing are the threats that currently confront the species within its
range and the likelihood that the species will persist in the
foreseeable future.
The petition used two sources of information for the distribution
and status of CRCT--Young et al. (1996) and the 1999 CAS (CRCT Task
Force 1999). While the Service considered these adequate and reliable
sources of information at the time of the original petition, new
information is also available to the Service, including the latest
information (CRCT Coordination Team, unpublished data) on numbers of
conservation populations and core conservation populations by State.
While the total number of conservation populations (106) and core
conservation populations (221) represents a relatively secure
subspecies, total numbers of populations does not provide the full
picture of the status of a species. The CAS (CRCT Task Force 2001)
recognized that some past and present land management practices
(overgrazing, heavy metal pollution, and water depletion and
diversions) contribute to the isolation of upstream populations of
CRCT. In some cases those practices serve to protect populations from
invasion by nonnative salmonids, but they also cause fragmented stream
segments that restrict movement between formerly connected populations,
leaving small isolated populations that may be subject to extirpation
and loss of genetic interchange (CRCT Task Force 2001). Many of these
populations occur in headwater streams where water temperatures and
small stream size make habitat conditions less than optimal. Harig and
Fausch (2002) noted that cold summer water temperatures, typical of
high elevation streams, tend to delay spawning, which reduces
overwinter survival. They also found that many small streams lack
sufficient pools deep enough for overwinter survival. The work of
Novinger and Rahel (2003) also suggested that isolated headwater
mountain streams lack some of the necessary habitat components based on
the finding , in some cases, that isolation management (the process of
constructing an artificial barrier, removal of brook trout, and
stocking CRCT) resulted in more CRCT below the artificial barrier than
above. However, small, isolated populations have persisted for many
years in some situations, such as above waterfalls or in desert basins
(Hilderbrand and Kershner 2000). It is unclear what population and
habitat sizes are required for long-term population viability.
The scientific literature addresses species population viability in
a theoretical manner, providing recommendations for minimum population
size based on theoretical models (Franklin 1980; Gilpin and Soule 1986;
Rieman and McIntyre 1993; Hilderbrand and Kershner 2000). Through
modeling, Hilderbrand and Kershner (2000) estimated minimum stream
length for several subspecies of cutthroat trout (Colorado River,
Bonneville (Oncorhynchus clarki utah), and westslope (Oncorhynchus
clarki lewisi)), in relation to population size. They estimated that a
stream length of 3 km (2 mi) was required to support a population of
1,000 fish; 8 km (5 mi) to support 2,500 fish; and 17 km (10 mi) to
support 5,000 fish. Recent data show stream lengths for core
conservation populations vary from less than 1.5 km to 34 km (less than
1 mi to 21 mi), with 77 of the 191 (40 percent) core conservation
populations in stream segments of 3 km (2 mi) or less (CRCT
Coordination Team, unpublished data). Core conservation populations of
CRCT ranged in size from 20 to 6,830 adult fish, with the majority (92
percent) of the adult populations having either fewer than 1,000 fish
or no available population data. However, it is important to recognize
that the Coordination Team has not adopted the population criteria
discussed above and has not developed specific standards for population
viability for CRCT (CRCT Task Force 2001). The Coordination Team
considered using the criteria for demographic and habitat requirements
for bull trout (Salvelinus confluentus) as presented by Rieman and
McIntyre (1993), but determined those criteria were not appropriate for
CRCT. While limited habitat size, small population size, inappropriate
water temperatures, and habitat fragmentation are a concern, its
unclear how these factors affect the long-term viability of the
subspecies.
When addressing a species with multiple populations, such as CRCT,
population viability is just one factor to consider when determining
the likelihood of species persistence. The CAS stresses the
establishment of metapopulations to assure the long-term prosperity of
CRCT (CRCT Task Force 2001). The CAS defines metapopulations as ``a
collection of localized populations that are geographically distinct
yet are genetically interconnected through natural movement of
individual fish between populations.'' Metapopulations are important
for stabilizing population dynamics by maintaining genetic exchange
(increasing genetic diversity) and providing individuals to repopulate
stream segments where populations are lost due to stochastic
environmental events (i.e., fire, drought) (UDWR 1997). The long-term
goal of the CAS is to
[[Page 21154]]
establish two self-sustaining metapopulations, each consisting of five
separate, viable but interconnected subpopulations, in each geographic
management unit within the historic range. Two of the 14 geographic
management units currently meet the long-term goal of the CAS. The
short-term goal is to establish one metapopulation in each geographic
management unit. Seven additional geographic management units currently
meet the CAS short-term goal. Overall, metapopulations currently exist
in Colorado, Utah, and Wyoming, where 11 metapopulations meet the
criteria of 5 separate but interconnected subpopulations and an
additional 23 metapopulations contain 2 to 4 subpopulations (CRCT Core
Coordination Team, unpublished data).
The States are actively working to establish metapopulations in
each geographic management unit. For example, in Wyoming, a large
restoration project is currently ongoing to establish a metapopulation
in the LaBarge watershed in the southwestern portion of the State.
Completion of this project is expected 2007, and will result in
restoration of 58 stream miles, including 18 miles of LaBarge Creek and
40 stream miles of tributaries (Remmick 2002). Challenges in
establishing metapopulations include difficulty in obtaining approval
for chemical treatments, reinvasion of nonnative trout, funding, and
landowner approval. Based on their work in Colorado, Brauch and Hebein
(2003) found that current technical limitations of chemical treatments
for reclamation limit potential reclamation sites to smaller streams
with low flows of less than 0.42 cubic meter/second (15 cubic feet/
second). State efforts to overcome these challenges continue.
The Service recognizes that overgrazing can be detrimental to trout
habitat, and that overgrazing may occur in some habitats occupied by
CRCT. The petition asserted that habitat conditions are degraded in a
significant portion of the subspecies' range. Descriptions of habitat
conditions are not available for the CRCT on a rangewide basis (Bruce
May, USFS, pers. comm. 2003). The petition used the habitat limitations
data field presented in Appendix A of the CAS to draw this conclusion.
However, this data field is not adequate to determine the habitat
condition of individual streams or lakes or to determine the condition
of the habitat rangewide (Dan Brauch, CDOW, pers. comm. 2003). This
data field was not applied consistently in the three States, nor was it
applied consistently over time. In many cases, habitat limitations
noted for the survey location did not apply to the entire stream reach.
The CAS (CRCT Task Force 2001) stated that ``habitat problems are
viewed as site-specific and not an overall threat throughout the
range,'' but no documentation was provided. The petition did not
provide additional substantial information to determine the extent of
overgrazing in CRCT habitat. Furthermore, the Service can not assume
that all livestock grazing within the CRCT habitat is inappropriate.
Proper grazing management can reduce or prevent the habitat and water
quality degradation discussed in the petition.
The Service recognizes that water diversions can negatively impact
CRCT habitat. The petition asserted 59 CRCT populations have been
negatively impacted by water diversions. However, the petition relied
primarily upon the habitat limitations data field presented in Appendix
A discussed above. A rangewide inventory has not been conducted to
determine if water diversions are a problem in just a few locations or
throughout CRCT range. Many CRCT populations occur in stream segments
upstream of water diversions, and some instream flows have been secured
in CRCT streams in Colorado and Wyoming. In Utah, the State Engineer
has the authority to deny any changes in water rights applications if
such action ``affects the natural stream environment or public
recreation.''
Additionally, the petition asserted mining, dams and reservoirs,
oil and gas development, road building and logging may be detrimental
to CRCT populations. The petition also asserted that mining, through
isolation, and dams and reservoirs have preserved pure populations of
CRCT. Information on the impacts of dams and reservoirs, oil and gas
development, road building and logging is not available on a rangewide
basis. The petition did not provide substantial information to
determine the rangewide impact on CRCT habitat. We have no other
information establishing these activities as significant threats to
CRCT.
The USFS and the BLM are currently implementing conservation
actions on Federal lands to improve habitat conditions for CRCT (USFS
2002, BLM 2003). These actions include grazing management by
constructing fencing, building exclosures, and resting grazing
allotments. Other vegetation management activities to improve riparian
conditions include weed control and riparian plantings. The BLM has
recently facilitated installation of a fish screen to prevent CRCT from
entering a water diversion structure and implemented culvert
improvements to provide fish passage. The USFS has moved campsites and
excluded vehicle access to improve habitat for CRCT. The Federal
agencies have partnered with the State agencies to monitor fish
populations, build and maintain barriers, and remove nonnative fish.
Some CRCT habitats are afforded protection from land use activities by
special land use designations, such as habitats within Rocky Mountain
National Park and USFS Wilderness Areas.
We find the petition did not provide substantial information to
support its assertions that the threat of past and present destruction,
modification, or curtailment of CRCT habitat is sufficient to cause
further significant declines in this subspecies' range or extant
populations. We conclude that the total number of conservation
populations and core conservation populations represent a relatively
secure subspecies. While limited habitat size, small population size,
inappropriate water temperatures, and habitat fragmentation are a
concern, it is unclear how these factors affect the long-term viability
of the subspecies. State management efforts to establish
metapopulations in each geographic management unit continue to improve
the outlook for the CRCT. Further, the petition failed to provide
substantial information to support the allegation that overgrazing,
mining, logging, or roads pose a threat to the overall habitat or range
of the CRCT.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
With respect to factor B, the petition asserted that CRCT are
threatened by recreational fishing, because CRCT are easy to catch and
the state regulatory agencies lack sufficient funding to enforce
protective regulations effectively. Colorado, Utah, and Wyoming all
have special regulations that provide protection against overharvest of
CRCT. These special regulations include catch-and-release requirements,
very limited harvest, fishing closures, and tackle restrictions. Also,
the remote locations of many CRCT streams provide protection from heavy
fishing pressure (CRCT Task Force 2001).
The CDOW placed harvest and tackle restrictions on most
conservation populations of CRCT in 1999. These regulations prohibit
harvest of CRCT and allow anglers to only use flies and lures (i.e., no
bait). The CDOW reports that 49 waters with conservation populations
are closed to cutthroat trout harvest and 1 lake is closed to fishing
(Brauch and Hebein 2003). In Rocky
[[Page 21155]]
Mountain National Park, all waters that contain pure native cutthroat
trout are limited to catch-and-release angling (except Caddis Lake and
Lake Nanita, where there is a two-fish daily limit), and some waters
are closed to angling while restoration efforts are being implemented
(Rosenlund et al. 2001).
In the early 1980s, the WGFD implemented regulations to better
manage CRCT waters. Some waters have complete fishing closures; other
waters are catch-and-release only, reduced limits, and seasonal
closures. The WGFD continually revises fishing regulations to protect
species of concern (Remmick 2002). The WGFD assigned a warden to
enforce fishing closures near CRCT habitat when roads were constructed
in association with the Cheyenne Stage II Water Project in the Little
Snake River drainage in Wyoming (Remmick 2002).
In Utah, the UDWR has established seasonal closures, reduced
limits, size restrictions, and implemented fishing closures in areas of
recent introductions to protect CRCT. The UDWR has not observed small,
remote populations getting enough fishing pressure to influence numbers
and size structure (Kimball 2001).
While the petition recognizes that existing fishing regulations are
in most cases adequate, it raises concerns that funding for education
and enforcement programs may be inadequate. However, the petition and
information available in the Service's files fails to provide
documentation to support this assertion.
Based on the existing regulations described above, we conclude that
the scientific and commercial information available does not support
the assertion that overutilization by recreational angling is a threat
to CRCT. Furthermore, the petition failed to present substantial
information regarding a lack of sufficient funding for education and
enforcement of the regulations.
C. Disease or Predation
With respect to factor C, the petition asserted that CRCT are
threatened by whirling disease and the CDOW stocks whirling disease-
infected fish within the historic range of CRCT. Also, the petition
asserted that CRCT are threatened by predation from brown, brook, and
rainbow trout. In recent years, whirling disease has become a great
concern to fishery managers in western States. Whirling disease is
caused by the nonnative myxosporean parasite, Myxobolus cerebralis.
This parasite was introduced to the United States from Europe in the
1950s and requires two separate host organisms to complete its life
cycle. Its essential hosts are a salmonid fish and an aquatic worm,
Tubifex tubifex. Field experiments have shown that CRCT are very
susceptible to whirling disease, with an 85 percent mortality rate over
a 4-month period when CRCT were exposed to the parasites in the
Colorado River (Thompson et al. 1999). However, Tubifex tubifex is
usually most abundant in areas of high sedimentation, low water
temperatures, and low dissolved oxygen. Most populations of CRCT occur
in cold water stream habitats at high elevations, where Tubifex tubifex
is unlikely to be abundant. Thompson et al. (1999) found infection
rates to be low when temperatures are less than 10[deg]C (50[deg]F).
Out of the hundreds of CRCT populations reported by the States, only a
few populations of CRCT in Utah and Wyoming have been infected by
whirling disease (Kimball 2001, Remmick 2002). In Colorado, CDOW has
not found any native cutthroat population infected with whirling
disease (Nesler 2003). Wyoming reports that no core conservation
populations or conservation populations have been infected (Remmick
2002). All three States have developed management activities to protect
CRCT populations from whirling disease.
In Colorado, policies require that only fish that have tested
negative for Myxobolus cerebralis, within the last 60 days are
permitted to be released into CRCT waters. Colorado also requires
disease-free certification and requires the use of isolation/quarantine
units for CRCT stocks (CRCT Task Force 2001). Utah has some of the most
stringent fish disease laws in the United States. Utah has a Fish
Health Board that oversees the disease testing protocol. Utah does not
allow stocking of fish that test positive for whirling disease anywhere
(CRCT Task Force 2001). A couple of CRCT waters in Utah have been
infected by whirling disease, and the UDWR is studying the effects of
whirling disease on these populations (Kimball 2001). Wyoming has a
policy that any fish testing positive for Myxobolus cerebralis will not
be stocked (Remmick 2002).
We find that the scientific and commercial information available
supports the allegation that CRCT are susceptible to whirling disease,
but due to the physical characteristics of CRCT habitat and the current
State policies, whirling disease does not pose a significant threat to
CRCT.
Predation was recognized in the petition in association with the
presence of nonnative trout in CRCT habitat. The CRCT are often
replaced by nonnative trout, primarily brook trout (Salvelinus
fontinalis), where they occur in the same habitat; but the degree to
which predation is a factor in this replacement has not been well
studied (Peterson and Fausch 2002). We find that there is insufficient
information to conclude that predation by nonnative fishes is a
significant threat to CRCT.
D. The Inadequacy of Existing Regulatory Mechanisms
With respect to factor D, the petition asserted that currently
there are no regulations protecting the species from take or habitat
degradation. The petition and subsequent correspondence failed to
recognize all of the ongoing efforts of the signatories of the 2001
Conservation Agreement. The States of Utah, Wyoming, and Colorado, and
the Federal land management agencies all have ongoing programs to
conserve the CRCT.
Colorado Division of Wildlife
The CDOW includes the CRCT on a list of species of special concern.
Colorado fishing regulations provide restrictive regulations for some
CRCT waters. These restrictions include angling limited to artificial
flies and lures and immediate return of all trout alive to the water. A
recent report outlines conservation activities conducted by the CDOW
during 1999-2002 (Brauch and Hebein 2003). The CDOW reported that,
during this period, 311 streams and lakes were targeted for
conservation activities. Statewide conservation activities included
restrictive tackle and catch-and-release regulations, regulations
prohibiting nonnative stocking into conservation populations, and
stocking CRCT for recreation into high lakes. Other conservation
activities included development of subbasin brood stocks, removal of
nonnative trout, protection of populations with barrier construction,
genetic testing, and population monitoring. The Colorado Water Quality
Control Division and Commission regulate water quality and set water
quality standards to protect aquatic life in coldwater environments.
Utah Division of Wildlife Resources
Utah lists CRCT as a conservation species, which is defined as
currently receiving sufficient special management under a conservation
agreement to preclude listing as endangered, threatened, or species of
special concern in Utah. Utah's stocking practices have changed in
recent years to protect CRCT. Stocking of nonnative fishes no longer
occurs near core conservation populations or conservation populations.
In 2002, Utah discontinued
[[Page 21156]]
stocking rainbow trout in most streams and now only stocks sterile
rainbow trout. Sterile rainbow trout are stocked only in areas that
have no connection to CRCT habitat. All stocking of nonnative
cutthroats was discontinued by 2000. Utah fishing regulations restrict
harvest of CRCT and implement fishing closures during restoration
activities.
Wyoming Game and Fish Department
Wyoming protects CRCT through fishing regulations and stocking
procedures. Restrictions on angling include reduced bag limits, catch-
and-release fishing, seasonal closures, and complete closures. The WGFD
has filed for water rights on a total of 30 stream segments of CRCT
habitat, for a total of 187 km (116 mi). Priority dates for these
filings range from 1989 to 2002. To date, two instream flow rights have
been approved. The Wyoming State Division of Environmental Quality
implements water quality regulations and controls that apply to CRCT
waters.
U.S. Forest Service
The USFS has designated CRCT as a sensitive species. According to
the USFS, the petition misrepresented their aquatic habitat management
program and land-use coordination by taking statements in reports out
of context (USFS 2003). The U.S. Department of Agriculture policy
directs the USFS to manage ``habitat for all existing native and
desired nonnative * * * species in order to maintain at least viable
populations of such species and to avoid actions that may cause a
species to become threatened or endangered.'' While specific population
viability criteria have not been established by the CRCT Coordination
Team, this policy requires the USFS to make a judgment on the viability
of each individual population where authorized activities may impact
CRCT.
The 2001 CAS was used as a basis for recovery and conservation
strategies for Standards and Guidelines within individual Forest Plans,
in combination with the Fisheries and Aquatic Ecology section of the
Forest Planning Desk Guide. For example, the standards for the White
River National Forest Plan in Colorado include provisions to: maintain
or enhance existing CRCT habitat; reduce sediment from existing roads
and trials; maintain pool depths; maintain riparian vegetation; and
retain large woody debris in streams. Guidelines to implement these
standards include restriction on new roads, rerouting existing roads,
decommissioning old roads, altering timing of grazing, excluding
sensitive or problem areas from grazing, and controlling livestock
crossings. In the past 5 years, the USFS has completed 200 biological
evaluations that address CRCT.
The USFS (2002) reported that the Rocky Mountain Region in 2002
implemented 51 conservation actions that positively influenced 64 lake
ha (158 lake ac) and 727 stream km (452 stream mi) of CRCT habitat.
Projects included inventory of existing and potential habitat, drought
salvage, fencing to exclude cattle, stream assessment and monitoring,
nonnative trout removal, building and maintaining barriers, moving
dispersed campsites, and genetic analysis. Over the last 4 years the
USFS has provided $2,097,100 for the implementation of 112 conservation
actions.
Bureau of Land Management
The CRCT is on the BLM's Sensitive Species List. The BLM prepares
Work Plans and Accomplishment Reports for conservation efforts on BLM
lands in Colorado, Utah, and Wyoming. Conservation actions are either
planned or have been implemented on approximately 40 CRCT streams.
National Park Service
The current fisheries management objectives in Rocky Mountain
National Park were established in 1969, when the stocking of nonnative
and hybrid fishes was no longer permitted. Lakes that did not maintain
reproducing populations of fish became fishless (Rosenlund et al.
2001). Five sites that contain core conservation populations within
Rocky Mountain National Park are open to catch-and-release fishing, and
four other sites have a two-fish limit. Most CRCT waters within the
Park are in high-elevation remote locations, where angling pressure is
very light. Livestock grazing, timber harvest, mining, or other
development does not occur in Rocky Mountain National Park.
The scientific and commercial information available does not
support the petition's assertion that there are no regulations
protecting the species from take or habitat degradation. We conclude
that take of the subspecies can be controlled by State regulations and
that the Federal land management agencies have policies to manage
sensitive species habitat.
E. Other Natural or Manmade Mechanisms
With respect to factor E, the petition asserted that a major threat
to CRCT is competition and hybridization from nonnative trout species
occurring in the same habitat as CRCT. It also asserted that small
isolated populations of CRCT are vulnerable to stochastic events, such
as fire or drought. Hybridization with nonnative fish species has been
recognized as one of the most significant threats to CRCT (Behnke 1992;
Young et al. 1996; CRCT Task Force 2001). Hybridization occurs when
nonnative species interbreed with CRCT, and the offspring survive. The
nonnative species that hybridize with CRCT are primarily rainbow trout
and other subspecies of cutthroat trout. If the hybrids survive and
interbreed with one or both of the parental species, it is called
introgressive hybridization. This can lead to loss of genetic purity in
the population and result in a population that consists entirely of
individuals that contain genetic material from both species (i.e., a
hybrid swarm). Nonnative salmonids have been stocked in CRCT habitat
since the late 1800s throughout CRCT historic range. The State agencies
have spent considerable time and money in recent years testing
populations to determine their genetic purity.
Determining genetic purity is a complex issue and a single standard
has not been established. Methods used by the States to determine
genetic purity have changed over the years. Analysis by meristics
(counts of body parts) was used for many years, but now various
molecular genetic techniques (i.e., mitochondrial deoxyribonucleic acid
(DNA), nuclear DNA, allozymes) are available and can detect very small
amounts of introgression. Many of the core conservation populations
have been confirmed to be pure (<1 percent="" introgression)="" with="" these="" molecular="" genetic="" techniques.="" many="" other="" test="" results="" are="" pending.="" in="" general,="" scientists="" have="" found="" that="" genetic="" testing="" confirms="" the="" results="" of="" the="" earlier="" meristic="" techniques="" (brauch="" and="" hebein="" 2003;="" hepworth="" et="" al.="" in="" press).="" all="" three="" states="" continue="" the="" process="" of="" genetic="" testing,="" using="" the="" latest="" techniques.="" an="" evaluation="" of="" known="" stocking="" history="" and="" genetic="" and="" meristic="" information="" is="" considered="" in="" determining="" core="" conservation="" populations.="" current="" policies="" preclude="" stocking="" of="" nonnative="" trout="" in="" crct="" habitat,="" and="" recent="" genetics="" work="" has="" added="" significantly="" to="" the="" number="" of="" core="" conservation="" populations="">99 percent pure). As of
July 2003, 221 core conservation populations are known to exist in
Colorado, Utah, and Wyoming. There are varying amounts of information
available regarding the genetic purity of these core conservation
populations. Since 1999, Wyoming has added 20 core conservation
populations and Colorado has added 25 core
[[Page 21157]]
conservation populations as the result of genetic testing. Some
populations are added to the list of core conservation populations, and
others are dropped from the list as genetic testing continues. Far more
populations have been added to the list of core conservation
populations through genetic testing than have been removed (Brauch and
Hebein 2003; Conway 2003; Stone 2003). In addition to the core
conservation populations, there are 106 conservation populations that
are classified as 90 to 99 percent pure.
Hybridization continues to be a threat where nonnative species,
particularly rainbow trout (Oncorhynchus mykiss) and nonnative
cutthroat trout, occur in the same habitat as CRCT. The most recent
data show that only 8 of the 221 core conservation populations coexist
with rainbow trout or another subspecies of nonnative cutthroat trout
(although information on presence of nonnative salmonids is not
available for 22 of the populations). Because core conservation
populations are defined as 99 percent pure, one would expect
a very low occurrence of other species or subspecies that are known to
interbreed with CRCT in the core conservation population waters.
Competition from nonnative trout, especially brook trout, also has
been recognized as a major threat to CRCT (Behnke 1992). Studies have
shown CRCT are displaced when brook trout occur in the same habitat. A
recent study conducted by Colorado State University found survival of
young CRCT was greatly impacted by the presence of brook trout, while
adult CRCT survival was not impacted (Peterson and Fausch 2002). Since
2001, four conservation populations in Colorado (Corral Creek, Cub
Creek, Express Creek, and Nolan Creek) have been completely displaced
by brook trout (Brauch and Hebein 2003).
Brook trout are no longer stocked in CRCT waters in Colorado, Utah,
or Wyoming. Recent data (CRCT Coordination Team, unpublished data) show
that brook trout are absent from 139 of the 199 core conservation
populations that have been surveyed for nonnative salmonids.
Recognizing the threat posed by brook trout, the responsible agencies
are actively implementing management techniques, such as the
construction of barriers, the removal of brook trout, and the
curtailment of stocking brook trout within CRCT waters. Between 1999
and 2002, Colorado, Utah, and Wyoming completed chemical treatments in
36 CRCT waters, for a total of 88 stream miles and 87 lake acres in 8
geographic management units (CRCT Coordination Team, unpublished data).
Colorado also removed brook trout by electrofishing in 20 waters.
Fish barriers have been constructed on CRCT streams to prevent the
upstream movement of nonnative salmonids. The CAS identifies the
construction of barriers as a strategy to protect and restore existing
habitat. It also recognizes that natural barriers can be effective.
Recent data show 117 (53 percent) of the existing core conservation
populations are currently protected by a natural or artificial barrier
(CRCT Coordination Team, unpublished data). However, the Service
recognizes that barriers are not a guarantee that non-natives will not
be present in CRCT habitat. Thirty-two percent of the core conservation
populations with barriers have nonnative salmonids present.
Ultimately, a larger watershed approach may be necessary for the
long-term persistence of CRCT populations (Hilderbrand and Kershner
2000).
The Service recognizes that stochastic events can be detrimental to
individual populations of CRCT. The primary goal of the CAS is to
establish metapopulations within each geographic management unit to
assure the long-term prosperity of CRCT. While all the specific
metapopulation goals of the CAS have not been met, metapopulations
connecting 2 or more streams do occur in 14 out of the 15 geographic
management units (Table 3). The Service agrees with the assertion in
the petition that once an isolated population is lost, there are no
natural means for these populations to recruit new members. However,
management actions have been taken by the States to repopulate CRCT
streams after stochastic events. For example, during the 2002 drought,
Colorado salvaged fish from Trapper Creek and West Antelope Creek and
held the fish in refugia for return to the wild when conditions
improved and for the establishment of broodstock for supplying fish for
stocking into the respective hydrologic subbasins (Brauch and Hebein
2003).
Although some CRCT populations are threatened by hybridization, we
conclude that the threat of hybridization is not pervasive to the
extent that it poses a risk to the continued survival of CRCT. The
Service recognizes that nonnatives can outcompete CRCT. However, brook
trout are absent from 139 of the 199 core conservation populations that
have been surveyed for nonnative salmonids. Management techniques such
as the construction of barriers, the removal of brook trout and the
curtailment of stocking brook trout within CRCT waters are currently
being implemented by responsible agencies. Therefore, we conclude that
the petition and other documents in our files do not provide evidence
that competition with brook trout presents a significant threat to the
subspecies within the foreseeable future. While stochastic events will
always pose a threat to individual populations, the establishment of
metapopulations and state management actions should minimize this
impact.
Finding
We conclude that the petition and other documents in our files do
not present substantial information to lead a reasonable person to
believe that listing the CRCT as threatened or endangered may be
warranted. After reviewing recent data, we conclude that there are a
significant number of core conservation populations of CRCT distributed
throughout historic range and that agencies are implementing management
actions to improve the status of these populations. Since 1998, 125
stream populations and 29 lake populations have been added to the list
of conservation populations for a total of 286 stream populations and
41 lake populations. This increase in population numbers can be
attributable to results of genetic testing, removal of nonnatives, and
stocking. The total number of conservation populations and core
conservation populations represents a relatively secure subspecies. The
States and the Federal agencies report that there are currently 11
metapopulations with 5 or more interconnected subpopulations and 23
metapopulations with 2 to 4 interconnected subpopulations. Work is
ongoing to establish additional metapopulations throughout the CRCT's
historic range. The Federal land management agencies are currently
implementing conservation actions in CRCT habitat such as grazing
management, recreation management, weed control, and riparian
plantings. The State and Federal agencies work cooperatively to
construct and maintain barriers, remove nonnative fish, and monitor
fish populations.
The petition asserted that overgrazing, water diversions, mining,
dams and reservoirs, oil and gas development, road-building and logging
are detrimental to CRCT. The Service finds the information in the
petition was not adequate to assess the impacts rangewide. While
limited habitat size, small population size, inappropriate water
temperatures, and habitat fragmentation are a concern, it is unclear
how these factors affect the long-term viability of the subspecies.
[[Page 21158]]
We do not agree with the petitioners' conclusion that none of the
populations can be considered secure because every one is threatened by
nonnative fishes, limited stream length, habitat limitations, or a
combination of these factors.
Historically, overharvest of CRCT may have significantly reduced
the numbers of CRCT in some areas, but we find that fishing regulations
enacted by the States and the National Park Service provide measures
that preclude excessive take by recreational angling. The petition did
not present substantial information indicating funding to enforce or
educate the public about these regulations was inadequate. Also, many
CRCT waters are located in remote locations that experience very light
fishing pressure.
Whirling disease is a significant concern for trout in general, but
very few CRCT populations have tested positive for the disease and all
three States are implementing management actions to protect CRCT from
whirling disease. Also, much of the habitat for CRCT is unlikely to be
conducive to the whirling disease pathogen. Therefore, we do not agree
with the petition's assertions that overutilization or whirling disease
present significant threats to CRCT. With regard to predation by
nonnative fishes, we find that there is insufficient information to
conclude that this issue is a significant threat to CRCT.
The Federal land management agencies all have programs in place to
regulate land management activities. The petition did not provide
evidence to support its allegation that these programs are not
providing adequate protection, and why they are not effective in
conserving CRCT. Service files do not contain adequate information on
habitat conditions to make an informed determination as to whether
Federal lands are being adequately protected or enhanced by existing
regulations and policies. Thus, the Service has no reason to assume the
programs in place for CRCT management are inadequate.
Although some CRCT populations are threatened by hybridization, we
conclude that significant numbers of populations have been determined
to be core conservation populations (99 percent pure).
Further, the States have implemented policies to protect the genetic
purity of the core conservation populations. Competition from brook
trout is recognized as a threat to CRCT and the State and Federal
agencies are implementing management techniques to offset this threat.
Many core conservation populations (53%) are protected by natural or
artificial barriers and the States have ongoing programs to remove
brook trout from CRCT waters.
The petition failed to recognize the ongoing conservation efforts
of the members of the CRCT Coordination Team. Numerous conservation
efforts are ongoing in all three States and in general appear to be
well funded. We conclude that the management programs currently in
place for CRCT are improving the status of this subspecies and
continued improvement is anticipated in the future. Therefore, as
required by section 4(b)(3)(A) of the ESA, we conclude that the
petition did not present substantial information to demonstrate that
the listing may be warranted. This finding is based on all information
available to us at this time.
References Cited: A complete list of all references cited herein is
available upon request from the Grand Junction, Colorado Field Office
(see ADDRESSES).
Author: The primary author of this document is Patty Schrader
Gelatt, Colorado Field Office, Grand Junction, Colorado.
Authority: The authority for this action is the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
Dated: April 8, 2004.
Elizabeth H. Stevens,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 04-8633 Filed 4-19-04; 8:45 am]
BILLING CODE 4310-55-P
