1. Estimating Steelhead Abundance in a High Sediment Stream: Bridge Creek, Oregon
Ian Tattam
Nick Bouwes
Chris Jordan
Michael Pollock

2. Outline 1) Why trap steelhead in Bridge Creek? 2) 2009 Methods
3) 2009 Escapement Estimate
4) Spawner Distribution

3. Large Lower Mainstem John Day tributary
Why Bridge Creek?
Large Lower Mainstem John Day tributary
Suspected presence of hatchery adults
Tributary-scale restoration efforts
Point out locations of Murderers and Bridge creeks, again note paired watershed design.

5. Where’s the redd?
Good example of channel incision prevalent on the public lands downstream of Mitchell. Briefly mention the restoration plan.

6. 1) 2009 Methods Upstream/Downstream Adult Trap Mark-recapture estimate
Proportion of hatchery strays?
Operated 4/5/2009 to 5/28/2009
PIT tag (cheek)
Caudal punch

7. Trap

9. Fish
Fish
Current

11. There really are steelhead in that muddy water!
April adult female entering Bridge Creek.

13. 3) 2009 Escapement Estimate Captures: Upstream: 126 Downstream: 84
Downstream Recaptures: 23
Population Estimate: 449 (344 to 625)
Capture efficiency
Upstream: 28%
Downstream: 19%

14. 3) 2009 Escapement Estimate
CV: 15.3% for combined wild and hatchery estimate
Population size underestimated - late trap install
19% hatchery - likely an underestimate

15. Adult Length by Origin “A” “B”
Note presence of Group-B Hatchery strays, in addition to Group A strays. (Group B fish are to the right of the line, if separated by length).

16. Pic of one of the ad-clipped hatchery B run fish captured in Bridge
Pic of one of the ad-clipped hatchery B run fish captured in Bridge. Holding tub is 32” long, fish spans it and then some.

17. 4) Spawner Distribution

18. RKM 12
RKM 26
PIT Detection Sites

19. Detection of Upstream Migrating Adult Steelhead
Wild: 57%
Hatchery: 19%
Wild: 17%
Hatchery: 0%
Detection of Upstream Migrating Adult Steelhead

20. Conclusions
Steelhead are entering and spawning in Bridge Creek over a 3+ month period
Downstream trap box and seining combined resulted in sufficient recaptures
Flexible pickets allowed operation in high stream flows / velocities

21. Conclusions
Hatchery adults appear to spawn lower in the creek than wild adults
Low reproductive success for steelhead spawning in RKM 1-9
Are hatchery adults self-regulating?

22. Acknowledgements Permitting: Jeff Neal and Chris James
Construction: Steve Corwin, Mike Jensen, Kelly Stokes, Lonnie Goin, Kirt Cook, Glen Moodenbaugh
Installation: Chris James and Nick Weber
Handling/Tagging: Dan Rawding
Trap Operation: Bryn Fleming