1. Evaluate juvenile salmon residence in the Columbia River Plume using micro-acoustic transmitters John Ferguson, et al. Riverine Ecology Program NWFSC, Seattle, WA

3. Juvenile Chinook Distribution in the CR Plume

4. Ocean Conditions TrophicInteractions Salmon Abundance Distribution Growth MesoscaleSurvey Pacific Northwest Coastal Environment Plume Environment Strategy : Role Of Columbia River Plume on Salmon Productivity Direct Measurements & Modeling

5. Approach: collaborative team to downsize tag technology for subyearlings (92mm) -Columbia River estuary: -fixed and mobile detection systems -make survival estimates from Bonneville to mouth -delayed mortality; migration behavior -habitat selection -Lake Washington - urban estuary -Columbia River Plume - residence

6. Application Process: -characterize acoustic environment -model signal propagation -design detection system -set tag criteria -prototype test -full scale monitoring

7. micro-acoustic tag (proposed) Turbine tags: 2001 2000 subyearling chinook smolt (92 mm) Radio tag, NMFS survival study, 2002 120 kHz PIT tag

8. Locks Fremont Cut Montlake Cut Lake Union Salmon Bay Shilshole Bay

10. Plume study products: -Compare residence times -ocean- and stream-type chinook -early versus late migrants within a season -large versus small fish -Characterize fine-scale spatial use of frontal regions -Integrate with Project 199801400 to understand how climate, ocean, and river forcing interact to affect survival

11. Summary : -apply micro-acoustic methodology to plume residence using fixed and mobile arrays -life history, seasonal, size differences -risks: adequate sample sizes; fixed array design; cost; detection range due to phase shift encoding *answer critical uncertainty of temporal and spatial use of plume habitat by juvenile salmon