1. Map: Courtesy of Bonneville Power Administration Drainage Area: 660,480 km 2 Estuary Area: 412 km 2

2. Data Source:Thomas, T.W.1983. Changes in Columbia River estuary habitat types over the past century. CREDDP. Habitat Changes in the Columbia River estuary Total area loss = 24% 0 10,000 20,000 30,000 40,000 50,000 Deep WaterMedium DepthShallow/FlatsTidal Marsh & Swamp Uplands- Natural & Filled Acres 1870 1980 - 7 %- 25 % + 10 % - 65 % + 293 %

3. HISTORIC AND MODERN COLUMBIA RIVER ESTUARY FOOD WEBS Pre-1870 Modern (1980) DETRITUS PHYTO- PLANKTON PHYTO- PLANKTON FLUVIAL INPUT FLUVIAL INPUT DETRITUS PHYTO- PLANKTON EMERGENT PLANTS BENTHIC ALGAE PHYTO- PLANKTON DETRITUS ZOO- PLANKTON ZOO- PLANKTON EPI- BENTHOS ? ? ? ? ? EPI- BENTHOS ZOO- PLANKTON ? BENTHOS ZOO- PLANKTON ZOO- PLANKTON ZOO- PLANKTON 80000 EPI- BENTHOS EPI- BENTHOS BENTHIC ALGAE EMERGENT PLANTS 159185 ? ? ?? 7300090002514649510261440 4056024 ? 11324 1545 3605 36205 1893 355 14587 3426 282167 279 167 26 10525 5300 19938 62629 1825 1943 OCEANIC EXPORT OCEANIC EXPORT BENTHOS

4. Effects of Flow Regulation Reduced peak freshet flow by >40% Freshet longer and peak flow earlier Greatly increased fall-winter minimum flows 1970-1999 Monthly Average Flows at The Dalles

5. Recommendations from Salmon at Rivers End 1.Monitor life-history diversity, habitat use, and performance of juvenile salmon 2.Protect and restore emergent and forested wetlands and riparian floodplains 3.Use physical observations and modeling to assess changes in habitat opportunity 4.Assess the effects of altered habitats and food webs on juvenile salmon

6. Marsh trap (habitat scale) Beach seine (landscape scale) Estuarine Monitoring: Salmon Abundance & Life History

7. Salmon-Habitat Relationships Emergent & Forested Wetlands Fish abundance and life history Prey availability and fish food habits Physical attributes Vegetative communities D. Bottom, NMFS & C. Simenstad, UW

8. Estuarine Monitoring and Modelling: Physical Attributes & Habitat Opportunity CORIE Historical, active Historical, recent extensions Historical, temporarily discontinued This project, active Planned for 2002 Biological monitoring water level (pressure) salinity temperature velocity profiles (5 sites)

9. Habitat Change Assessment completed 1983 Focus area of NMFS project Columbia River Estuary Habitat Change Analysis

10. Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary and Their Implications for Managing River Flows and Restoring Estuarine Habitat Ed Casillas, Daniel Bottom, Curtis Roegner, Kym Jacobson, & Cathy Tortorici National Marine Fisheries Service Charles Simenstad University of Washington Antonio Baptista, David Jay, & Todd Sanders Oregon Graduate Institute Eric Volk Washington Department of Fish and Wildlife

11. Reconstruct historic changes in estuarine rearing opportunities and food-web linkages of Columbia River salmon and evaluate their implications for managing river flows and restoring estuarine habitats. Research Goal Simulation Modelling: 2. Effects of change on habitat opportunity? Food-Web Sources: 3. Effects of change on salmonid food webs? Restoration Scenarios: 4. Implications for restoration? Historic Reconstruction: 1. Baseline conditions and modifications?

12. Establish a consistent historic habitat baseline from the river mouth to Bonneville Dam. Develop baseline of aquatic, intertidal, and floodplain habitats from historic T-Sheet and H-Sheet data. Reconstruct historic climatic, tidal, and hydrologic effects on overbank flooding and access to floodplain. Historic Reconstruction

13. Use historic baseline to run 3-D simulations of habitat opportunity based on selected criteria: --depth (0.1-2.0 m) --velocity (< 30 cm/s) --salinity (< 5 ppt) Evaluate sensitivity of habitat opportunity to past (1) diking & filling, (2) flow regulation, and (3) channel deepening. Simulation Modelling

14. Food-web Sources Characterize changes in estuarine food webs of salmon and the organic sources supporting them 1. Stable isotopes: --Carbon sources of different salmon life-history types --Isotopic signatures of dominant estuarine and freshwater prey --Otoliths to assess changes in prey linkages 2. Parasites: --Parasite assemblages as indicators of diet and habitat use 3. Scale microchemistry: --Potential for describing historic food-web linkages

15. Restoration Scenarios Review results of monitoring, simulations, and historic analyses Identify alternative restoration scenarios (workshop). Construct simulation database for each scenario. Analyze impact of alternative scenarios for estuarine habitat and salmon