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The Status of Puget Sound Chinook Salmon

The Status of Puget Sound Chinook Salmon. What do we know? and How do we know it? Kit Rawson Tulalip Tribes. Salmon Recovery. What was the status of the resource historically?. How’d we get here?. What is the status of the resource now?. Recovery Plan.

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The Status of Puget Sound Chinook Salmon

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  1. The Status of Puget Sound Chinook Salmon What do we know? and How do we know it? Kit Rawson Tulalip Tribes

  2. Salmon Recovery What was the status of the resource historically? How’d we get here? What is the status of the resource now? Recovery Plan What is the desired future status of the resource?

  3. Salmon Recovery What was the status of the resource historically? How’d we get here? What is the status of the resource now? Recovery Plan What is the desired future status of the resource?

  4. Population Parameters (from “VSP”) • Abundance • Productivity • Diversity • Spatial Structure

  5. Abundance • Census of individuals (how many?) • Total biomass (how much?) • Count or biomass at: • single life stage • whole population

  6. Abundance • Census of individuals (how many?) • Spawning escapement • Eggs • Juvenile outmigration • Adult return

  7. Spawning Escapement

  8. Spawning Escapement • Smith and Castle (1994) • Redd counts (approx. weekly) • Aerial, foot, float surveys • Assume 2.5 fish/redd, 21-day “visible redd life” • Supplemented with peak live, dead counts • Varying methods for expanding to unsurveyed or poor visibility areas

  9. Spawning Escapement • No estimate of variance • No standard method for separating hatchery and natural-origin

  10. Adult Return • Run Reconstruction • Escapement • + Terminal harvest • + Mixed-stock harvest • Chinook complications • Immature fish harvest • Non-landed mortality • Age distribution

  11. Coded-Wire Tag Program

  12. Puget Sound ChinookMarine Survival Index

  13. Snoqualmie – Current Conditions Equilibrium = 2,300

  14. Snoqualmie

  15. Juvenile Outmigration

  16. Juvenile outmigration • Sampling error ( 0.75 – 1.65% captured) • Traps upstream of some rearing areas • Variable time and size of migration

  17. Puget Sound TRT A&P Workbooks • For each of 22 natural chinook populations

  18. Puget Sound TRT A&P Workbooks • Data (some incomplete) • Natural escapement estimates • Hatchery/natural origin split • Exploitation rate estimates • Juvenile production • Environmental predictors (marine survival, flow)

  19. Puget Sound TRT A&P Workbooks • Analyses • Run reconstruction • Trends and variance about trends • Spawner/recruit relationships

  20. Questions • Q: What are the best indices of salmon status to use across species and areas? • A: • Focus on natural populations/stocks • Look at trends in natural escapement and total return • Control for marine survival and other signals

  21. Questions • Q: Over what time period should we assess recovery? Can we separate factors affecting abundance on different time scales? Should we? • A: • 20 years + • Yes • Yes

  22. Questions • Q: How accurately do we need to measure salmon populations to effectively manage them? • A: • Management systems need to be robust to imprecise and inaccurate assessments of status • Even so, we probably need better estimates than we have now.

  23. Questions • Q: Regional or “top-down” approach best (both within and between ESUs)? • A: • Regional/local focus is best for adaptive management • Needs a few, well-understood guiding principles

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