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Overview  Modeling to date: –Distribution of mortality –Achieving improvements with specific actions  Building scenarios  Dealing with uncertainty –

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Presentation on theme: "Overview  Modeling to date: –Distribution of mortality –Achieving improvements with specific actions  Building scenarios  Dealing with uncertainty –"— Presentation transcript:

1 Overview  Modeling to date: –Distribution of mortality –Achieving improvements with specific actions  Building scenarios  Dealing with uncertainty – some ideas

2 Snake River Spring/Summer Chinook Life Cycle 2 spawners 4,000-5,000 eggs 120-151 1-year-olds to Lower Granite Dam 95-119 Migrants Below Bonneville Dam (77% transported, 23% in River) 4-5 Youngsters To 2nd Birthday (Estuary & Ocean) 2-3 Adults return to mouth of Columbia 1-1.4 Migrants return to spawning grounds

3 0.50 0.60 0.70 0.80 0.90 1.00 1.10 Lower Columbia Upper Columbia Spr Snake River Spr/Sum Snake River Fall Upper Willamette Columbia River Chum Lower Columbia Middle Columbia Upper Columbia Snake River Upper Willamette Population Growth Rate Hatchery fish reproductive success = 1 Hatchery fish reproductive success = 0 Rate of population change – Accounting for hatchery fish ChinookSteelhead

4 How can we give fish what they need to survive and recover?

5 Hydropower

6 Improvements to hydropower system  Past – passage improvements  Future options –Passage improvements »Flow and spill measures –Dam breaching

7 Past vs. current passage survival Snake River spr/sum chinook

8 Option 1 – anticipated changes with passage improvement

9 Harvest – maximum benefits

10 Are there life stages at which management actions might be most fruitfully aimed?

11 Sensitivity Test – Standard reductions in mortality

12 Snake River Spring/Summer Chinook Life Cycle 2 spawners 4,000-5,000 eggs 120-151 1-year-olds to Lower Granite Dam 95-119 Migrants Below Bonneville Dam (77% transported, 23% in River) 4-5 Youngsters To 2nd Birthday (Estuary & Ocean) 2-3 Adults return to mouth of Columbia 1-1.4 Migrants return to spawning grounds

13 Survival vs. sedimentation

14

15 Hatchery – Genetic concerns  Inadvertent selection due to hatchery practices reduces fitness of hatchery fish. Interbreeding of hatchery and wild fish may affect fitness of wild fish as well. –Domestication – seen in as little as a single generation –Stock transfers

16 Hatchery – Ecological concerns 1020304050 1020304050 -3 -2 0 1 2 Percent survival wild chinook (log) Number of hatchery spring chinook released (millions) r 2 = 0.06r 2 = 0.73 Average Ocean ProductivityPoor Ocean Productivity

17 Building scenarios  Combinations of actions – when one isn’t enough  Interactions between actions  Continuing degradation in habitat/other environmental factors

18 Major areas of uncertainty  Hatchery fish masking – what is the TRUE population status?  Interactions between life stages – does survival/growth/experience in one stage affect survival/fitness in another?  Impacts of particular actions

19 Snake River Spring/Summer Chinook Life Cycle 2 spawners 4,000-5,000 eggs 120-151 1-year-olds to Lower Granite Dam 95-119 Migrants Below Bonneville Dam (77% transported, 23% in River) 4-5 Youngsters To 2nd Birthday (Estuary & Ocean) 2-3 Adults return to mouth of Columbia 1-1.4 Migrants return to spawning grounds

20 Some possible approaches  Different questions – –What actions (or areas) are important REGARDLESS of the potential future? –Are there easy actions that might be useful for bet-hedging against an unlikely future? –Which pieces of information would be most important to have (would help us reduce our uncertainty)?


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