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Objectives : 1) Describe the current status of passage by Snake River subyearlings;

Passage Update for Natural-Origin Fall Chinook Salmon Subyearlings at Lower Granite, Little Goose, and McNary Dams in 2005. Objectives : 1) Describe the current status of passage by Snake River subyearlings; 2) Describe the current status of passage by Clearwater

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Objectives : 1) Describe the current status of passage by Snake River subyearlings;

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  1. Passage Update for Natural-Origin Fall Chinook Salmon Subyearlings at Lower Granite, Little Goose, and McNary Dams in 2005

  2. Objectives: 1) Describe the current status of passage by Snake River subyearlings; 2) Describe the current status of passage by Clearwater River subyearlings; 3) Provide a depiction of passage of the basin-wide population by use of 2004 PIT-tag detection data.

  3. Snake River Sampling

  4. Snake River Catch andFork Length

  5. Snake River Tagging andSurrogate Releases

  6. Use of the Sandford and Smith (2002) Method to Estimate Daily Passage: n^ = n / ^P; where n = observed PIT-tag detections and ^P = estimated detection probability.

  7. Clearwater River Sampling

  8. Clearwater River CatchandFork Length

  9. Clearwater River TaggingandSurrogate Releases

  10. Conclusions: • The PIT-tag data collected in both the Snake and • Clearwater rivers under represents subyearlings that are • less than 60 mm fork length that begin seaward • movement early in the rearing period. • 2) Estimates indicate that passage of natural fall Chinook • salmon of Snake River origin is nearly complete at Lower • Granite, Little Goose, and declining over time at McNary • Dam. • 3) Estimates indicate that passage of natural fall Chinook • salmon of Clearwater River origin is ongoing and will • likely continue from August through next spring.

  11. Key Remaining Critical Uncertainties that Impact Ability to Make Informed Decisions Emigration/movement during non-detection period: Inhibits estimation of juvenile survival. Inhibits estimation of smolt-to-adult survival (SAR’s) for non-detected (in-river) fish. Weakens estimation of representative population scale SAR. Masks true in-river over-wintering distribution. 2) Emigration response to spill conditions: Movement stimulation? 3) Lack of a collaborative monitoring, evaluation, and research plan to be applied across multiple policy/management forums: Need pre-labeled decisions. Need defined data quality/risk thresholds. Need standardized performance measures.

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