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• Mike Faler - USFWS, Ahsahka, ID
• Glen Mendel - WDFW, Dayton, WA
Evaluate Bull Trout Movementsin the
Tucannon & Lower Snake Rivers
Background
• Occurrence of bull trout at the Snake River dams is only incidentally known
• Status of the Tucannon River population is considered healthy
• It’s unknown if the hydropower system limits Tucannon River bull trout in completion of their migratory behavior
Background
• Occurrence of bull trout at the Snake River dams is only incidentally known
• Status of the Tucannon River population is considered healthy
• It’s unknown if the hydropower system limits Tucannon River bull trout in completion of their migratory behavior
Background
• Occurrence of bull trout at the Snake River dams is only incidentally known
• Status of the Tucannon River population is considered healthy
• It’s unknown if the hydropower system limits Tucannon River bull trout in completion of their migratory behavior
Limiting Factors identified in the Subbasin Summaries
• Data gaps– Out-of-basin effects
migration corridor survival
– Fish passage
– Entrainment/Fall Back
– timing of bull trout usage & extent
Identified Needs(Mainstem Snake Subbasin)
• Determine passage requirements of bull trout at Lower Snake River dams
• Determine presence and use of bull trout in the mainstem Snake River
- distribution, timing, & usage at the dams and reservoirs
Identified Needs(Tucannon Subbasin)
• Full assessment of distribution, habitat use, life history…
• Expand monitoring and assessments to enhance understanding of bull trout…
Objectives
• Determine the spatial distribution, migration timing, and movements….
• Determine bull trout use and passage efficiency in fishways….
• Estimate frequency of bull trout fall back….
• Determine if bull trout losses result from FCRPS operation….
Objectives
• Determine the spatial distribution, migration timing, and movements….
• Determine bull trout use and passage efficiency in fishways….
• Estimate frequency of bull trout fall back….
• Determine if bull trout losses result from FCRPS operation….
Objectives
• Determine the spatial distribution, migration timing, and movements….
• Determine bull trout use and passage efficiency in fishways….
• Estimate frequency of bull trout fall back….
• Determine if bull trout losses result from FCRPS operation….
Objectives
• Determine the spatial distribution, migration timing, and movements….
• Determine bull trout use and passage efficiency in fishways….
• Estimate frequency of bull trout fall back….
• Determine if bull trout losses result from FCRPS operation….
Methods
• Collect bull trout each spring at the Tucannon Hatchery Weir
Methods
• Surgically implant 1 or 2 year radio tags in 15-40 bull trout at the Tucannon Hatchery
Methods
• Monitor movements with mobile receivers
Methods
• Track using fixed receivers, winter-spring, 2002-2005
Analysis
• Delineate distribution and migration timing
• Calculated passage rates
• Determine occurrence & frequency of fall back
• Determine % return back to the Tucannon River
• Determination of loss
Tucannon Hatchery Bull Trout Trapping Data 1998-2002
YearTotal
# BT
Capture
Dates
Ave.
Length
1998 82 4/1 - 8/29 396 mm
1999 40 5/20 - 7/12 449 mm
2000 41 4/17 - 8/29 437 mm
2002 134 5/17- 6/26 404 mm
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
4/1/
01
5/1/
01
6/1/
01
7/1/
01
8/1/
01
Date
Cu
mu
lati
ve
% o
f C
ap
ture
1998 n=821999 n=402000 n=41
Cumulative Capture at Tucannon Hatchery Weir
2002
Length Frequency of Bull Trout Captured at WDFW Tucannon Hatchery, 2002
(n=105)
0
2
4
6
8
10
12
295 345 395 445 495 545
Length Categories (5 mm bins)
Ind
ivid
ual
Fre
qu
ency
Kilometers
0 3 6 9 -N-
Pataha Creek
Lo Mo Pool
Tucannon River
Little Tucannon River
Cummings Creek
Meadow/Panjab
Sheep Creek
Bear Creek
Tucannon Hatchery
Marengo
Fixed Telemetry Sites
Kilometers
0 3 6 9 -N-
Pataha Creek
Lo Mo Pool
Tucannon River
Little Tucannon River
Cummings Creek
Meadow/Panjab
Sheep Creek
Bear Creek
Tucannon Hatchery
Marengo
Spawning Distribution
Kilometers
0 3 6 9 -N-
Pataha Creek
Lo Mo Pool
Tucannon River
Little Tucannon River
Cummings Creek
Meadow/Panjab
Sheep Creek
Bear Creek
Tucannon Hatchery
Marengo
Current Distribution
Report Card
A+ Known distribution of migratory bull trout in the Tucannon River
Report Card I Known distribution of bull trout in the
Mainstem Snake River
Report Card
I Identified limiting factors in the FCRPS