The 2005 run year
annual report is one in a continuing series describing Washington
Department of Fish and Wildlife's progress toward meeting summer steelhead
and rainbow trout mitigation goals established in the Lower Snake
River Compensation Plan. The reporting period covers 1 July 2005 through
30 June 2006.
The LSRCP mitigation
trout program has focused on providing recreational fishing opportunities
in southeast Washington. Currently, the LFC goal is to produce 237,500
trout for release into southeast Washington area lakes to provide
for the 67,500 angler days of recreation. During the report period,
stocking of LSRCP produced rainbow trout within Washington and transfers
to the State of Idaho were less than planned.
The LFC raises
four summer steelhead stocks for the mitigation program (LFH, Wallowa,
Tucannon and Touchet). Program releases range from 50,000-160,000
depending on location, with all groups programmed for a release size
of 4.5 fish/lb. The numbers of steelhead released in 2006 were slightly
above program goals, but size goals were not met for the Wallowa,
Tucannon or Touchet stocks. Groups of hatchery steelhead released
into the Tucannon and Touchet rivers were also PIT tagged for estimation
of smolt-to-adult return rates since they are currently not marked
for harvest.
We operated a
rotary screw trap in the Tucannon River to estimate the number of
migrating natural steelhead smolts and other salmonids. We estimated
that 16,209, and 10,080 natural steelhead smolts emigrated from the
Tucannon River from the 2004/2005 and 2005/2006 trapping years, respectively.
Age compositions and characteristics of smolts captured from all years
are presented.
As part of our
annual broodstock collection and research activities, WDFW hatchery
and evaluation staffs operate a series of adult steelhead traps in
SE Washington. At LFH, a total of 1,674 adult steelhead were trapped,
with 120 females and 241 males spawned, producing 430,667 eyed eggs
to satisfy program goals. At Cottonwood Creek Trap, 2,006 adult steelhead
were trapped with 120 females and 115 males spawned producing 316,059
fertilized eggs for the program. At Tucannon Hatchery, staff trapped
20 natural, 18 Tucannon River endemic hatchery stock, and one LFH
stock hatchery-origin steelhead for the season; none of these were
collected for broodstock purposes. At the lower Tucannon Trap, staff
trapped 90 natural fish, 23 Tucannon River endemic hatchery stock,
and 48 LFH stock hatchery fish. Thirty-five of the natural fish were
collected for broodstock, of which 13 females and 17 males were spawned
for a total eggtake of 72,520. At the Touchet River Trap, staff trapped
164 Touchet River natural, 14 LFH stock hatchery, and 35 Touchet River
endemic hatchery steelhead. Thirty-nine natural origin fish were collected,
of which 18 females and 18 males were spawned for a total eggtake
of 88,668 eggs. For the second year in a row, three of the Touchet
River females tested positive for IHNV; the progeny from these fish
were planted into the Touchet River as fry (14,276 total).
WDFW personnel
surveyed steelhead sport anglers within the LSRCP area of Washington
to recover CWTs from tagged steelhead. During the 2005/2006 steelhead
sport fishery we surveyed 10,181 anglers that caught 3,236 steelhead,
of which 1,165 were natural origin fish Lyons Ferry Complex Hatchery
Evaluation: Summer Steelhead Annual Report 2005 Run Year June 2007
viii (36.0% of the total catch). In addition, we cooperate with ODFW
in conducting a joint survey of anglers on the lower Grande Ronde
River of Washington and Oregon. Angler effort, catch rates, and harvest
that were estimated by ODFW staff are presented.
During 2006, evaluation
staff surveyed spawning grounds in the Touchet River, Asotin Creek,
and Cumming Creek (Tucannon River Basin). High, turbid stream flows
much of season prevented us from conducting surveys in the Tucannon
River, and hampered our success in other areas.
The LFC summer
steelhead program (LFH and Wallowa stocks) continues to exceed the
original hatchery mitigation goal to the Snake River project area
by supplying hatchery fish for sport harvest. Based on creel surveys
and adult traps, we estimated that a minimum of 5,099 (3,156 goal/run
year) LFH stock and 2,339 (1,500 goal/run year) Wallowa stock fish
returned from the 2002 brood year. That represents 162% and 156% of
the Washington mitigation goal for each of these stocks, respectively.
However, original goals of the LSRCP also assumed that about ¾
of the annual return would be captured in downriver fisheries. To
date, the downriver harvest has not approached that rate of harvest,
mainly due to curtailment of fisheries in recent years due to ESA
listings.
As in previous
years, WDFW electrofished index sites to estimate natural juvenile
steelhead densities, derive population estimates for specific river
reaches, and to estimate residual hatchery steelhead. In addition,
we conducted mark/recapture tests to compare with our standard electrofishing
methods to examine bias in the estimates. In 2005 we found that the
multiple pass estimates of Age 0 and Age 1+ summer steelhead were
26% and 22% lower, respectively, than the mark/recapture estimates.
The relationships were highly correlated so the possibility of determining
a correction factor to previous years’ data looks promising.
Since 1998, the
Snake River Lab and WDFW’s Fish Management staff have periodically
collected samples from SE Washington summer steelhead populations
(adult and juvenile) for genetic stock analysis. Samples have been
collected from the Walla Walla, Touchet and Tucannon River basins,
the LFH stock, and portions of the Grande Ronde. During the fall of
2006, WDFW genetics staff, in cooperation with the Snake River Lab
and WDFW Fish Management for SE Washington assembled a summer steelhead
genetics summary that includes most samples collected through 2005.
The genetics report is provided as an Appendix to this report.
