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Data-moderate assessments for 9 groundfishes

Data-moderate assessments for 9 groundfishes. NWFSC and SWFSC STAT teams. Context and objectives. Data-moderate = catch and index data Methods (XDB-SRA and exSSS ) already reviewed. 3 Objectives Fit index data Provide stock status (depletion) Provide OFLs for 2015, 2016.

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Data-moderate assessments for 9 groundfishes

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  1. Data-moderate assessments for 9 groundfishes NWFSC and SWFSC STAT teams

  2. Context and objectives • Data-moderate = catch and index data • Methods (XDB-SRA and exSSS) already reviewed 3 Objectives Fit index data Provide stock status (depletion) Provide OFLs for 2015, 2016

  3. Things to expect • First data-moderate STAR panel • Base cases are currently fluid • Terms of Reference “open” • How much to show • How to present? • Executive summary • Many topics germane to “full” assessments • Future research topics important • How can we improve future applications?

  4. Biology and ecology Flatfishes Rockfishes Nearshore-shelf (<250 m) English sole Shelf-slope (up to 500 m) Rex sole Nearshore(<120 m) Shelf-Slope • Sharpchin • Stripetail • Yellowtail • North of 40.10 • South of 40.10 • Brown • China • Copper • Vermilion • North of Pt. C • South of Pt. C (“complex”) Table 1: Life history parameters

  5. Assessment scope Yellowtail Sharpchin China Vermilion Copper Stripetail Rex sole English sole Brown Yellowtail

  6. Generalized Linear Mixed Models (GLMM) • Model set-up • Delta approach: models positives (binomial) and magnitude of positives (lognormal or gamma) • Extreme Catch Events (ECE): modeled as a mixture distribution • Model Interpretation • Convergence: Neff > 500 • Goodness-of-fit: Q-Q plots (ECE or non-ECE?) • Model selection: Deviance (lognormal or gamma?)

  7. GLMM survey stratification: Rockfishes Sharpchin Stripetail Yellowtail

  8. GLMM survey stratification: Flatfishes English sole Rex sole

  9. GLMM: Model selection

  10. Interpreting trawl survey catchability “The distance between the trawl doors is three times greater than the distance between the wings on the NWFSC trawl (Figure 2). Since abundance data was expanded to the index of biomass using net wingspread, the survey biomass estimates are three times greater than if door spread was used. The subsequent estimate of q using door spread would therefore be approximately 1, one-third of the value estimated in the assessment. Catchability in a stock assessment is solely used as a scalar and is difficult to interpret. However, the observations of herding presented here illustrate one process that contributes to a larger than expected estimate of q.” -Bryan et al (in press)

  11. Hook and Line survey

  12. SSC Recommendations and Actions Taken

  13. SSC Recommendations and Actions Taken(cont.)

  14. Extended Depletion-based Stock Reduction Analysis (XDB-SRA) Extended Simple Stock Synthesis (exSSS) Common data (Catch, indices) Selectivity = maturity Age-structured Delay-difference Life history: Two-sex Life history: Single-sex VBGF parameters No growth parameters (no SPR) R0 prior (MLE;MCMC); depletion prior (AIS) Depletion prior Productivity: Steepness (h) Productivity: FMSY/M; BMSY/B0

  15. Depletion prior: Vulnerability analysis

  16. Depletion prior: Vulnerability analysis The 2012 review panelrecommended that we use three bins Unfortunately, the results were not captured in the report This is an attempt to re-create the analysis None of the 2013 assessment cases fall in the right-hand bin

  17. Depletion prior: Vulnerability analysis “Depletion”2000 = 65%: Stripetail, English and Rex sole Beta distribution peaks at right “Depletion”2000= 30%:Brown, China, Copper, Vermilions, Sharpchin, Yellowtails Beta distribution peaks at left The “uninformative” case is beta, based on all data Has not been used in any 2013 analyses

  18. Sharpchin rockfish

  19. Sharpchin rockfish: Index fits All surveys combined XDB-SRA Triennial- early Triennial- late NWFSC exSSS

  20. Sharpchin rockfish: Spawning biomass

  21. Sharpchin rockfish: Stock status

  22. Sharpchin rockfish: OFLs

  23. Sharpchin: Index fits with combined Triennial Triennial NWFSC

  24. Sharpchin: Combined Triennial

  25. Sharpchin rockfish: SSSvsexSSS

  26. Sharpchin rockfish: exSSS parameter estimates MLE AIS

  27. Sharpchin rockfish: exSSS steepness profile

  28. Sharpchin rockfish: exSSS steepness profile

  29. Sharpchin rockfish: exSSS sensitivities

  30. Stripetail rockfish

  31. Stripetail rockfish: Index fits All surveys combined XDB-SRA exSSS

  32. Stripetail rockfish: exSSS results

  33. Yellowtail rockfish North

  34. Yellowtail rockfish (N): Index fits Triennial NWFSC RecFIN CPFV XDB-SRA Tri early Hake bycatch RecFIN NWFSC exSSS Tri late Trawl CPUE CPFV

  35. Yellowtail rockfish (N): exSSS SB and depletion

  36. Yellowtail (N): Index fits with combined Triennial Triennial RecFIN Hake bycatch NWFSC CPFV Trawl CPUE

  37. Yellowtail (N): Combined Triennial

  38. Yellowtail rockfish N: exSSS results

  39. Yellowtail rockfish South

  40. Yellow rockfish (S): Index fits RecFIN cenCal/OR CPFV XDB-SRA exSSS

  41. Yellowtail rockfish S: exSSS results

  42. English sole

  43. English sole: Index fits Triennial- combined NWFSC XDB-SRA Triennial- early Triennial- late exSSS

  44. English sole: Spawning biomass

  45. English sole: Stock status

  46. English sole: OFLs

  47. English sole: Index fits with combined Triennial Triennial NWFSC

  48. English sole: Combined Triennial

  49. English sole: SSSvsexSSS

  50. English sole: exSSS parameter estimates MLE AIS

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