Estuarine Habitat and Juvenile Salmon: Physical Oceanography Component

1. Estuarine Habitat and Juvenile Salmon: Physical Oceanography Component David A. Jay and Thomas Chisholm ESE/OGI/OH&SU Thanks to Tobias Kukulka and Philip Orton Research supported by: United States Army Corps of Engineers, Portland District National Marine Fisheries Service Department of Environmental Science and Engineering, OGI/OHSU

2. Oceanography Elements FY 02: Task 1: Evaluate climate/human effects on salmonids through flow, tides, salinity and sediment input: • Continue analyses of tides, river flow and habitat • develop shallow-water habitat (SWHA) historical scenarios • Begin analysis of historic salinity data (underway) • Develop better Beaver flow, 1893-date (done) • analyze historical changes in sediment transport: • partition climate, human effects on transport • begin analysis of sub-basins (data archaeology) • coordinate with USGS – Menlo Park

3. Oceanography Elements FY 02 -- Task 2: Develop monitoring methods for sediment input to the Columbia River and estuary: • vital for understanding past/future changes in fluvial and estuarine habitats • contributes to analysis of long-term sediment balance, in relationship to climate and dredging • important for understanding toxic inputs by river • contributes to understanding inputs of detritus • test spring-freshet deployments at Beaver, May 2002, 2003

4. FY 02 Task 2 – Continued Monitor Sediment inputs at Beaver -- • Coordinate with Grand Canyon Monitoring Research Center work in Colorado R on testing, use of LISST-25x (two size classes, sand and fines) • Deploy LISST-FLOC at Beaver during the 2003 spring freshet • measures sizes from ~10 to 1500 microns in 32 size bins (clay to sand, flocs) at a high sampling rate • New version of LISST, needs to be tested • Calibration (concentration, size, organic content) • Analyze results with respect to sub-basin flows -- where is the SPM coming from? • Future – SPM dynamics of Cathlamet Bay channels

5. FY-02 Highlights -- • Tobias Kukulka M.S. degree, March 2002 • Kukulka and Jay, two papers for Journal of Geophysical Research: • Part I (submitted): methods for analyzing and hindcasting non-stationary river tides; compact and accurate • Part II (almost ready to go) applies methods of Part I and a simple stage model to analyze historic changes in shallow-water habitat area (SWHA) – see web posting • Jay and Naik, submitted to Geophysical Research Letters – separates climate and human influences on CR sediment transport • Tobias Kukulka – outstanding student presentation award, AGU winter meeting

6. FY-02 SWHA Results -- Analyses of shallow-water habitat area (SWHA) • Goal: develop a simple method to examine human and climate-induced changes in SWHA on scales of years to >100 years. Designed to complement numerical modeling • This year: developed method and initial scenarios for 1893-1998 for Skamokawa to Beaver reach • Focused on current flow management regime and channel configuration, 1974-98

7. SWHA Results: Skamokawa-Beaver Test Reach • Four tide gauges available: Skamokawa (I), Cathlamet (II), Westport (II) and Beaver (IV); interpolate for reach III • Compile modern bathymetry/hypsometry (with and w/o dikes) and hindcast tides and river stage, 1893-1998 for both virgin and observed flow • Good test reach: • large diked area • both tides and flow important,variable • topography nottoo complex • Historic topodata should beavailable soon

8. SWHA Results, Skamokawa-Beaver Test Reach: • Hypsometry forthe four sub-reaches • Dikes (grey lines) reduce inundated area until dikes are over-topped — No Dikes — Dikes

9. SWHA Results, Skamokawa-Beaver Test Reach: • SWHA as afunction of water depth in each reach • SWHA decreasesat high flows, because of flood-plain is deeplycovered • Dikes prevent floodplain inun-dation for most realistic flows — No Dikes — Dikes

10. Virgin flow, no dikes SWHA Results, Skamokawa-Beaver Test Reach: • Virgin flow provides much more SWHA for a lengthy period • Observed flow causes much more neap-spring variability in SWHA • With modern conditions (dikes, regulated flow), there is little seasonal variation in SWHA in dry years. Maximum may occur in winter Observed flow, no dikes Virgin flow, with dikes Observed flow, with dikes

11. SWHA Results: 1974 as a Test Case - • 1974 was one the highest-flow years of the 20th Century, with a highly modified flow cycle. • s = stage, R = range; h = historic (virgin) flow cycle, m = modified flow cycle • Virgin freshet eliminates tides at Beaver • Flow regulation decreases stage by ~1-1.5 m during freshet, increases tides • Flows & stage are increased rest of year, tides diminished • regulated flow had highest stage in winter • Habitat has been displaced to alower elevation and has a differentcharacter than historically

12. SWHA Results: 1974 as a Test Case –> Flow regulation reduces inundation (flood control works!)> Flood control+diking is much more effective than either alone> Dike removal alone would result only in winter inundation in many areas> Restoration of habitat may require both flow restoration and dike removal to be effective for salmon Observed flow, no dikes Virgin flow, no dikes

13. Initial Beaver Sampling,June 2002 -- • Beaver is long-time USGS flow and sediment sampling site • Used LISST-25, OBS, ABS, ADCP and water samples to measure flow and sediment properties • Will repeat with LISST-FLOC

14. Initial Beaver Sampling, June 2002 -- • SPM was vertically uniform, but laterally non-uniform • ABS, OBS and LISST give different views of SPM concentration; can be used to understand size spectrum and aggregation state • ABS “sees” coarser particles • OBS sees fines • LISST is strongly influenced by aggregates. High volume concentration suggests presence of many small aggregates, maybe plankton detritus

15. Human and Climate Influences on flow and Sediment Transport -- • Peak flows occur earlier, due to flow regulation, climate and flow diversion • All three factors influence sediment transport • Its easy to partition flow, harder to determine impacts on sediment transport ?PDO ColdPDO ColdPDO WarmPDO ColdPDO WarmPDO The Dalles Flow Day ColdPDO WarmPDO ColdPDO WarmPDO ColdPDO ?PDO The Dalles Flow Day

16. Virgin  Human and Climate Influences on flow and Sediment Transport -- 1971-99 Flows Adjusted Observed  • Peak flows are smaller, due to flow regulation, climate and flow diversion • All three factors influence timing and amount of sediment transport • Its easy to partition flow, harder to determine impacts on sediment transport irrigation Flow regulation 1879-99 virgin 1946-99 Virgin  1946-99 observed  Flow Changes Climate change  Total change 

17. Human and Climate Influences on flow and Sediment Transport -- 1879-99 virgin Total Load 1971-99 Virgin  1971-99 Observed  • Peak sediment transport occur earlier, due to flow regulation, climate and flow diversion • Changes in all three factors decrease sediment transport • Because of non-linear nature of sediment transport, there is a small ambiguity, the irrigation+regulation term Climate change irrigation +regulation Irrigation  Flow regulation  Changes in Total Load Total change 

18. Oceanography Elements FY 03 -- Task 1: Evaluate climate/human effects on salmonids through flow, tides, salinity and sediment input: • Continue analyses of tides, river flow and SWHA: • Interaction of power peaking with tide landward of Vancouver • Changes in salinity intrusion and stratification with flow and tidal range, historic and modern • Analyze SWHA scenarios • Develop Beaver virgin flow and virgin sediment transport • Look at sub-basin sediment input during 1964 flood • Coordinate with USGS Menlo Park on CR sediment supply

19. Oceanography Elements FY 03 -- Task 2: Develop monitoring methods for sediment input to the Columbia River and estuary. At Beaver: • Deploy LISST-FLOC at Beaver during the 2003 and 2004 spring freshets • Test 2003-04 winter deployment of LISST-FLOC, hopefully during a high-flow event • Small-boat surveys for calibration, spatial distribution (with ADCP, OBS, LISST-25X, also) • Calibrate/test LISST-FLOC with USGS Menlo Park • Analyze results with respect to sub-basin flows -- where is the SPM coming from? • Coordinate with USGS monitoring at Beaver

20. Oceanography Elements FY 03 -- Task 2 (continued): Develop monitoring methods for sediment input to the Columbia River and estuary. In Cathlamet Bay: • Test field program, spring freshet 2003 • Measure sediment texture/character (grab samples) • Use stakes to measure deposition during freshet • Use moored ADV (~1 mo) to look at currents, bedstress, SPM concentration (sand, flocs), changes in bed elevation, settling velocity and sediment transport at one location • Use moored OBS (~1 mo) to look at concentration of fines; pressure gauge for elevation • Small-boat surveys for calibration, spatial distribution (with OBS, LISST-25X, also) • Coordinated with Si and Dan