The Touchet River
originates in a network of deeply incised streams on the northwestern
slopes of the Blue Mountains and from seasonal streams draining the
Palouse hillsides to the north (Mendel et. al. 2001). Fish habitat
has been severely degraded by urban and agricultural development,
grazing, tilling, logging, recreational activities and flood control
(Mendel et. al. 2001). Historically bull trout were thought to be
widely distributed in the Touchet River watershed. Factors which have
elevated the water temperatures such as damaged riparian vegetation,
increased sedimentation and decreased water flows have also decreased
the range of this cold water species (Mongillo 1993).
The Washington
Department of Fish and Wildlife (WDFW) has captured and enumerated
bull trout at the adult steelhead trap in Dayton, in southeast Washington,
each spring for the past several years while trapping steelhead as
part of the Lower Snake River Compensation Program (LSRCP). Captured
subadult and adult bull trout apparently over winter downstream of
Dayton and return to headwater areas within several of the Touchet
River tributaries during late spring and early summer to hold over
until spawning. Similar movements have been documented in the Tucannon
River, which is the adjacent watershed to the east of the Touchet
River (Martin et al. 1992 and Underwood et al. 1995). The spatial
and temporal distribution of bull trout in the Touchet River during
winter and spring is currently unknown.
In the spring
of 2000, WDFW proposed a cooperative bull trout radio telemetry project
that was implemented in 2001 and 2002. This project was initiated
to provide a better understanding of the spatial and temporal distribution
of migratory bull trout in the Touchet River. It was anticipated that
the study would also assist the Confederated Tribes of the Umatilla
Indian Reservation (CTUIR) with a steelhead telemetry study in the
Walla Walla River basin, and help identify migratory barriers or passage
problems in the Touchet River watershed. Bull trout migration information
is critical for identification, prioritization, and selection of habitat
protection and restoration efforts in the Touchet River. The project
was also intended to help determine whether bull trout populations
in the upper Touchet River tributaries are genetically isolated from
one another, as well as from Walla Walla Basin populations. This information
would be valuable for determining the level of risk of extinction
for these populations. This projected 3-4 year radio telemetry study
was intended to provide information necessary for determining the
river reaches and habitat used by subadult and adult bull trout and
adult steelhead, and to identify critical habitat areas for maintaining
these populations. By providing information about connectivity and
potential genetic exchange among bull trout populations in the Touchet
River, and other Walla Walla Basin populations, managers and the public
could examine potential risks of population extinction and determine
the importance of protecting or expanding small, isolated spawning
habitats.
In 2001, WDFW
secured a small amount of funding from the USFWS Section 6 funds for
bull trout work, and from the Columbia County Conservation District.
These funds enabled WDFW to initiate this telemetry project by purchasing
surgical supplies, 20 radio tags, a telemetry receiver and yagi antenna
in early 2001. Radio tagging and tracking began in spring 2001.
This project complements
several other salmon recovery efforts in the Touchet Watershed and
the Walla Walla Basin. It is expected to provide critical data for
bull trout and steelhead that would fill data gaps identified in the
yet-unpublished Walla Walla Watershed Assessment Report (WSU and CTUIR)
and in ?Chapter 11: Umatilla ? Walla Walla Recovery Unit? of the Bull
Trout (Salvelinus confluentus) Draft Recovery Plan (USFWS, 2002).
These data gaps have also been identified in the recently completed
publication Salmonid Habitat Limiting Factors Water Resource Inventory
Area 32 – Walla Walla Watershed (Kuttel 2001). This project
also complements the BPA funded project Assessment of Salmonids and
Their Habitat Conditions in the Walla Walla River Basin of Washington:
2001 Annual Report that examines adult bull trout spawning, and juvenile
bull trout rearing distribution and relative abundance (Mendel et.
al., 1999, 2000, and 2001). The Walla Walla telemetry coordination
group that designed and is currently implementing the Walla Walla
river basin bull trout and steelhead telemetry projects supports this
project. The intent of this study is to fulfill the need for bull
trout migratory behavior and over-wintering information in the Touchet
River.
This project includes
many partnerships, and is partially funded from several sources. The
Columbia County Conservation District, the US Fish and Wildlife Service
(USFWS) Section 6 monies, the US Forest Service (Pomeroy District),
and the Tristate steelheaders provided funding, equipment or materials
for this project. WDFW contributed labor to administer the project,
to assist with tagging and tracking, and to provide technical oversight.
The Touchet bull trout project also contributed to a much larger radio
telemetry study in the Walla Walla Basin that includes partnerships
with several Irrigation Districts, the Walla Walla Watershed Council
in Oregon, the Oregon Dept. of Fish and Wildlife and the CTUIR. Their
contributions included funding and donated labor or materials for
the bull trout and steelhead radio telemetry study in the mainstem
Walla Walla and Mill Creek. They were to supply us with bull trout
telemetry data in areas they radio track (including the lower Touchet
River, Mill Creek and the Walla Walla River) and we were to provide
them with bull trout and steelhead radio telemetry data for the Touchet
River upstream of Plucker Road (river mile 14.9). The CTUIR was responsible
for radio tagging steelhead in the lower Walla Walla River, Mill Creek,
and the lower Touchet River, and summarizing the data obtained. The
WDFW was also a member of the technical oversight committee for the
larger telemetry effort for steelhead and bull trout in the Walla
Walla Basin. WDFW involvement in all projects helped ensure that the
proposed Touchet River bull trout project and the other Walla Walla
Basin efforts were well coordinated and that resources and data were
shared.
This radio telemetry
project was an assessment of the movements of migratory bull trout
in the Touchet River. The project was proposed to address the following
objectives:
1) Determine
spatial and temporal distribution of migratory bull trout in the
Touchet River.
1a) Determine
migration timing, distribution, and possibly habitat use downstream
of spawning and juvenile rearing areas in the Touchet River, 1b)
Determine migration timing and distribution in spawning and rearing
areas upstream of Dayton,
1c) Determine
whether Touchet River bull trout migrate far enough downstream
to enter the Walla Walla or Columbia rivers during winter or spring.
2) Determine
the level of interaction or isolation among bull trout populations
within the Touchet River system, and contribute to a larger study
of bull trout movements and interactions for the entire Walla Walla
Basin.
3) Identify
passage problems or delays and movements at fish passage facilities
or other obstructions in the Touchet River system.
4) Assist CTUIR
and their cooperators by collecting supplementary steelhead telemetry
data in the Touchet River to contribute to a larger multi-agency
and private effort to examine steelhead and bull trout spatial and
temporal distribution, movements, and passage in the Walla Walla
Basin.
The study design
was to capture and radio tag up to 30 bull trout annually from the
Touchet River for 2-3 years. Fish were to be captured in an existing
trap at a small dam in Dayton, by hook and line, or with electrofishing,
if necessary. Selected fish were radio tagged by surgical implantation
of digitally encoded transmitters in the abdominal cavity. The tags
emit unique codes per fish with an expected tag life of one to two
years. Fish were to be tracked with mobile receivers and by several
fixed-site receivers deployed at selected sites in the Touchet River
basin. Mobile fish tracking was to occur throughout the year at a
frequency of approximately 1-3 times per week during periods of intensive
tracking, and approximately once every two weeks when fish were not
moving extensively. Fixed-site receivers were to be downloaded approximately
once every two or three weeks.
Radio telemetry
appeared to be the most feasible way to obtain the desired information
on migration movements and timing, and to determine interaction or
isolation of bull trout populations within the Touchet River drainage
and the Walla Walla River basin.
