Holly J' McLellan and Allan T' Scholz

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Kokanee Tracking StudyLake Roosevelt, 2008

• Holly J. McLellan and Allan T. Scholz
• Eastern Washington University

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Lake Roosevelt Kokanee

• Two types of kokanee exist in Lake Roosevelt
• Hatchery reared
• Whatcom and Meadow Creek stocks
• Utilize spring fry and yearling plants
• 100 marked (otolith mark or adipose fin clip)
• Wild origin
• Origin unknown, potential to have multiple origin
  sources
• Data gaps in life history, habitat use and
  movements

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Wild origin kokanee

• Comprise 67 of the angler harvest
• average 2-4 pounds
• Hydroacoustic surveys
• Warm water temp force kokanee into deep water
  during summer months (gt 50m)
• Result in 30-50 m diel migrations during summer
  months to feed
• Kokanee growth models using bioenergetics
• (M. Mazur and D. Beauchamp)
• Data gap of kokanee movements below 50mm (150 ft)

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Objectives

• Conduct a three year acoustic study
• Monitor kokanee thermal and depth experience
  throughout the year to determine if kokanee were
  making diel vertical migrations.
• Data collected incorporated into the
  bioenergetics model for kokanee metabolism.
• Obtain additional information about kokanee fall
  migrations
• when and where spawn.
• First year , determine if even possible.

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Lake Roosevelt Study Area

• Grand Coulee Dam
• 243 km long
• Study area
• Lower 58 km (36 mi)
• Spring Canyon to Lincoln
• SanPoil River

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Methods

• Angle during the winter months (Feb April)
• Surgically implant Vemco V9 acoustic tags (n 19)
• Temperature and depth sensors
• 69 kHz frequency
• 120 sec nominal delay
• 496 day life
• 47 mm long, 6.4 g weight (12 in or greater)
• Monitor fish movements
• Passively VR2w deployable receivers
• Manually VR100 receiver

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Methods_ Angling

• 12 Feb and 25 March 2008, 8 sampling trips
• Trip
• 3-5 boats fishing sunup to sundown
• Once kokanee was caught, radioed me
• Special care was taken to reduce stress which
  increased survival
• Soft mesh nets
• Cut line if lure was stuck
• Once on my boat, held in oxygenated water until
  surgery

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Methods_Surgery

• Sterilize , wash tools (ethanol, distilled water)
• Anesthetize (MS-222 or CO2)
• Knock down
• Maintenance
• Incision
• Insert tag
• Suture
• Nexband
• DNA sample
• Floy tag
• Recovery cooler
• Release

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VR2w Receivers

• VR2w range 2km
• Record codes
• Anchor set up
• VR2w down 5 m
• Points down

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Array Design
SanPoil River
Swawilla Basin
Whitestone Area
Spring Canyon
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Results_Kokanee captured
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Statistics

• Mean length 473 mm (18.5 in.)
• Three age classes
• 440-470 (17-18.5)
• 490-520 (19-20.5)
• 560 (22 in)
• Mean weight 1,028 g
• (2.3 lbs)
• Strong length weight relationship

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Results

• Dates collected data
• 2 fish summer/fall data
• 14 short data collection
• 3 mortalities

• Movements
• x last detection
• 4 upstream
• 1 downstream
• 9 moved between Swawilla Basin and Spring Canyon
• 1 Spring Canyon, Whitestone and back

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Fish 12

• Marked 18 March 2008 across Spring Canyon BL.
• 461 mm, 460 g
• Upstream / downstream movements,
• lost contact on 28 April.
• Stayed near surface
• Diel vertical migration to 50 and 90 meters
• Water temps 3 and 8 C

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Fish 12 - Vertical Migration

• Swawilla Basin
• April 12
• Surface in morning
• Migrated down to 50 m (150 ft) between 3 hr
  window
• Back to the surface by 1130 pm.
• April 24
• Surface at 600 am
• Migrated to 90 m (243 ft) 3 hr window
• Back to the surface by 1100 pm

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Conclusions

• Kokanee move around the Swawilla/ Spring Canyon
  area a lot
• Make migrations to the Whitestone area and back
• Not related to spawning
• Make diel vertical migrations in spring
• Deep migrations not related to water temperature

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Reasons for detection loss

• Angler harvest
• Entrainment
• Poor receiver coverage
• Delayed tagging mortality
• Behavior response
• Tag failure

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2009 Changes

• Increased array coverage
• Reservoir and below dam
• Increased tags to 25
• 2009 tagging already complete

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Acknowledgments

• Thank the Spokane Tribe of Indians and the
  Washington Department of Fish and Wildlife for
  the assistance with catching our study fish.
• Thank the Spokane and Colville Tribe for
  purchasing additional VR2ws for the lower
  reservoir array.
• Special thanks to Mitch Combs, Rex Gerhart and
  Matt Howel for VR2 deployment
• Special thanks to EWU students (Candance Hultberg
  and Mark Paluck).
• Funding agency Spokane Tribe of Indians via
  Bonneville Power Administration

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Questions ?