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

Map: Courtesy of Bonneville Power Administration

Drainage Area: 660,480 km2

Estuary Area: 412 km2

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 Water Medium Depth Shallow/Flats Tidal Marsh &Swamp

Uplands- Natural& Filled

Acr

es

1870

1980- 7 % - 25 %

+ 10 % - 65 %

+ 293 %

HISTORIC AND MODERNCOLUMBIA RIVER ESTUARY FOOD WEBS

HISTORIC AND MODERNCOLUMBIA RIVER ESTUARY FOOD WEBS

Pre-1870Pre-1870 Modern (1980)Modern (1980)

DETRITUS DETRITUS PHYTO-PLANKTON

PHYTO-PLANKTON

FLUVIAL INPUTFLUVIAL INPUT

DETRITUS PHYTO-PLANKTON

EMERGENT PLANTS

BENTHIC ALGAE

PHYTO-PLANKTONDETRITUS

ZOO-PLANKTON ZOO-

PLANKTON

EPI-BENTHOS

? ?

? ?

? EPI-BENTHOSBENTHOS

ZOO-PLANKTON

?

BENTHOS

ZOO-PLANKTON

ZOO-PLANKTON

ZOO-PLANKTON

80000

EPI-BENTHOS

EPI-BENTHOSBENTHOS

BENTHIC ALGAE

EMERGENT PLANTS

159185 ?? ? ?

73000 9000 25 146495 10261440

40560 24

?

11324

1545

3605 36205

1893

355

14587

34 26

282 167279

167

26

10525

5300

1993862629

18251943

OCEANIC EXPORTOCEANIC EXPORT

BENTHOS

Effects of Flow Regulation

• Reduced peak freshet flow by >40% • Freshet longer and peak flow earlier• Greatly increased fall-winter minimum flows

1970-1999Monthly Average Flows at The Dalles

Recommendations from Salmon at River’s 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

Marsh trap (habitat scale)

Beach seine (landscape scale)

Estuarine Monitoring: Salmon Abundance & Life History

Salmon-Habitat RelationshipsEmergent & Forested Wetlands

• Fish abundance and life history

• Prey availability and fish food habits

• Physical attributes

• Vegetative communities

D. Bottom, NMFS & C. Simenstad, UW

Estuarine Monitoring and Modelling: Physical Attributes & Habitat Opportunity

CORIEHistorical, active

Historical, recent extensions

Historical, temporarily discontinued

This project, active

Planned for 2002

Biological monitoring

• water level (pressure)• salinity• temperature• velocity profiles (5 sites)

Habitat Change Assessment completed 1983

Focus area of NMFS project

Columbia River Estuary Habitat Change Analysis

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 VolkWashington Department of Fish and Wildlife

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?

• 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

• 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

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

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