1. Timing and distribution of naturally produced coho salmon in the lower Columbia River
Good morning, Today I’m going to give you an overview of the joint fall alternative gear and LCR coho run-timing evaluations.

2. Presentation overview
Background
Preliminary results
Management implications
Conclusions & recommendations

3. Background Declines in lower Columbia River coho salmon
Hatchery supplementation reestablished abundance
Reduced genetic diversity and hatchery effects on population
Federally listed in 2005 as “threatened”
Critical uncertainties research needed (avoidance vs mark selective)

4. Conceptual condition Time Although
Strictly from a fisheries management perspective the condition conceptualized in the top figure would make setting seasons that minimize intercepting naturally produced fish easier than the lower figure, which would provide little chance of avoiding encounters with naturally produced fish.
Time

5. Estuary Receiver Mainstem Gate Tributary Gate Metric 2011 2012
Date of 1st effort
8/28/2011
8/7/2012
Date of 1st capture
Date of last effort
10/31/2011
10/30/2012
Date of last capture
10/19/2011
Days fished 69
132
Total coho captured
460
971
Coho captured/day
6.7
7.4
Total instrumented
129
303
Total August instrumented 2 48
Instrumented/day
1.87
2.30
Estuary Receiver
Mainstem Gate
Tributary Gate
We used a system of stationary acoustic receivers, (estuary, mainstem, tributary) to track the movements of released coho through the LCR.

6. 129 coho instrumented in 2011, 303 in 2012
LCR Tributary
2011
2012
Elochoman River 1 2
Clatskanie River --
Mill Creek
Cowlitz River 7 9
Lewis River 5
Scappoose Creek
Clackamas River
Washougal River
Sandy River
Willamette River 19
129 coho instrumented in 2011, 303 in 2012
In heard in tributaries of interest, 15 over Bonneville
In heard in tributaries of interest, 44 detected over Bonneville
Excluding Willamette avg/trib ~ 2 fish
Only Washougal didn’t have coho detected at gates, but more had fish only hit at one or vacate

7. Results
The peak of the hatchery return was in stat week 36 and for Natural origin fish is was week 38, though as you can see there is some staying power on the hatchery front. And While there are some significant differences in the run timing data (for instance Hatchery vs wild are different from each other in all weeks except the tails and week 38) and the proportions vary significantly from the excepted on a weekly (and monthly for that matter) basis. You tell me, from a fisheries management standpoint, does this more resemble this? Or this? <POINT>

8. Results
Is there anything useful we can take out of this then? Maybe…It doesn’t look like (at least based on confidence intervals) that fish destined for interior basins are swimming much faster in the river than those destined for LCR tributaries, but it does appear that they hit the estuary than their lower river counterparts, and it also appears that they exit the lower river not only earlier than their lower river counterparts. If we are concernced primarily with LCR coho then you could target fisheries earlier.

9. Results Year Ultimate Fate LCR Tributary Bonneville Dam 2011 9/10/2011
9/8/2011
2012
9/15/2012
8/26/2012
Hatchery vs Unmarked fish tough to see, what about entrance by fate?

10. Results

11. Conclusions
Multi-modal run-timing is not apparent in 2012 for CR coho salmon
Upper river fish appear to enter river earlier than lower river counterparts
Distance and speed positively correlated
Need to increase acoustic presence in estuary tributaries to greater account for fish
Need to increase transmitters out to get better presence in non-Willamette lower river tributaries

12. Desired Status
Given that white sturgeon have a long life cycle, we need to identify both the desired future condition and some benchmarks along the way in order to measure progress and stay on track. Female sturgeon first spawn at about 25 years old and can live a hundred years so we need to consider VERY long timeframes. 20 generations is often used in the salmon world for modeling population responses and persistence, however, for sturgeon that will take about 500 year, considering how much has changed around here in the last 500 years we need some more proximate checkpoints.
This graph is just for adults, but we have similar checkpoints for sub-adults. Remember desired status is healthy and fully harvestable, and that is this line and when modeling this we assumed that productivity will be closer to recent historical averages – which we think is reseasonable because we have seen strong year classes recently and strong year classes substantially increase productivity. However, even if productivity stays at recent low levels we expect the population to have this sort of trajectory.
Why the decline and overlap for so long? Simply put, management actions today take a long time to be realized in the fishery and in the adult population.