1. Evaluation of Steelhead Kelt Passage through the Bonneville Dam Second Powerhouse Corner Collector Prior to the Juvenile Migration Seasons, 2007 and 2008
Mark Weiland and Gary Johnson – PNNL
Jina Kim - PSMFC
Bill Nagy – Fisheries Field Unit, USACE

2. Background
Surface flow outlets, which readily pass juvenile salmonid migrants, may also be an effective non-turbine passage route for steelhead kelt (Oncorhynchus mykiss) moving downstream in early spring before the main juvenile emigration season.
At the Bonneville Dam Second Powerhouse, a surface flow outlet, called the corner collector (B2CC), has been routinely operated to pass juvenile salmonids since 2004.

3. Objectives For each year separately, estimate
total number of kelt-sized fish1 passing into the B2CC,
run timing,
diel distribution,
vertical distribution.
1 Kelt-sized fish were defined as those with a mean target strength greater than -36 dB || 1Pa at 1 m, or approx. 30 cm long fish.

4. Methods
To evaluate the potential use of the B2CC by steelhead kelt, we performed a fixed-location hydroacoustic study during
March 2 to April 10, 2007
March 13 to April 15, 2008.
Six side-looking split-beam transducers were arrayed vertically and deployed from a barge anchored to the dam south of the B2CC entrance.
Ping rate = 33 pings/sec
Data quite “noisy” with vortices at the same target strength as kelt sized targets
Suite of filters used on the data to remove noise but retain targets of interest

5. Methods – Split Beam Transducers

6. Methods – Filtering (good target)

7. Methods – Filtering (passive target)

8. Results - Passage Rates
2007
2008
Total Fish Passed
172
223
No. per Day 4 7

9. Results - Run Timing
Sporadic
Increasing numbers in April

10. Results - Diel Distribution
No distinct trends in either year

11. Results - Vertical Distribution
No strong vertical trend

12. Adult Salmonid Counts in the B2 Juvenile Bypass System
Year
Adult Steelhead Count in the JBS*
2003
595
2004 59
2005
160
2006 46
2007 16
2008 5
PIT Detected
* Courtesy of Dean Ballinger, PSMFC

13. Conclusion and Management Implication
The B2CC, a much safer route for fish than turbines, can be an effective route for passing steelhead kelt.
This finding has management implications for operations at Bonneville Dam to protect steelhead kelt in early spring.

14. Acknowledgements
USACE - Jon Rerecich, Ben Hausman, Tammy Mackie, and BON rigging crew
PNNL – James Hughes, Shon Zimmerman, Matt Wilberding, Tyrell Monter
PSMFC – Eric Fischer