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COLUMBIA RIVER SALMON CUMULATIVE IMPACTS EXAMPLE.

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Presentation on theme: "COLUMBIA RIVER SALMON CUMULATIVE IMPACTS EXAMPLE."— Presentation transcript:

1 COLUMBIA RIVER SALMON CUMULATIVE IMPACTS EXAMPLE

2 Cumulative Effects Assessment 2 Example Learning Goals This example will provide insights into:  The complexity of ecological systems  Biological uncertainty; understanding is always incomplete  Interactions between ecology, economics and policy  Effects of institutional complexity; institutional roles must continually evolve

3 Changes in Salmon Catch Associated with Hydropower Development

4 Columbia River and Human Development

5 Development Timeline 1850 1900 1950 Present Unregulated fishery Initiate fishery regulation US Federal Reclamation Act Irrigation New hydroelectric dams Add power capacity Flood control PNW Conservation Act

6 Development and Impacts on Salmon Mortality on young Mortality on adults Loss of spawning habitat Altered hydrology Pollution Power Production Agriculture Flood Control Urban & Industrial Fisheries & Wildlife

7 Cumulative Impacts and Habitat FRESHWATER Reduced Flows Predator Irrigation Siltation Reduced Flows Irrigation Turbines Predators Harvesting Spillways Obstacles Spillways Pollution Harvesting Pollution Estuary Downstream Losses - Smolts Upstream Losses - Smolts

8 Cumulative Impacts and Harvest OCEAN US Harvest Canadian Harvest 20 Year Climate Cycles Productivity Predators Years 2 - 4 Known annual harvest ?

9 Cumulative Effects Assessment 9 Summary of Impacts  Direct Impacts »Losses at dams, habitat degradation, harvest, predation  Indirect Impacts »Hydrology alteration »Oceanic cycles  Impacts not additive and linear

10 Measuring Impacts on Columbia River Salmon  Catch and effort data  Counts at dams  Spawning escapement estimates  Tag returns AbundanceData Understanding

11 Cumulative Effects Assessment 11 Mitigating Cumulative Impacts in the Columbia River  Fish Protection »Transport around dams »Dam renovation or removal »Water flow »Harvest restrictions  Enhanced Fish Production »Hatcheries, artificial spawning channels  Habitat Restoration »Protected areas: natural spawning beds »Forest management

12 Cumulative Effects Assessment 12 Institutional Complexity  Many agencies ‘steer the course’  Requires explicit consensus building  Requires long-term commitment of funding

13 Cumulative Effects Assessment 13 Unpredictable Events Effects on Columbia River Migrations:  ~1978 - 1982: Failure of Nuclear Power  Mitigation actions (small scale)  Ocean temperature cycle (large scale)

14 Cumulative Effects Assessment 14 Concluding Thoughts Important points to remember are:  Cumulative impact problems are conceptually complex  Mitigation is expensive and its effectiveness uncertain  Common interests are more important than special interests

15 Cumulative Effects Assessment 15 Concluding Thoughts (Cont’d) Additional points to remember are:  Biological uncertainty is large  Institutional complexity exceeds traditional approaches or experience  Surprise is expected


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