1 / 38

MSE of the performance of data-moderate assessment methods for U.S. West Coast groundfish

MSE of the performance of data-moderate assessment methods for U.S. West Coast groundfish. Chantell Wetzel Data-Moderate STAR Panel April 23-28, 2013. Outline. Description of Assessment Models DCAC, DB-SRA, exDB -SRA, and exSSS (AIS) MSE Simulation Setup Operating model

darius
Download Presentation

MSE of the performance of data-moderate assessment methods for U.S. West Coast groundfish

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. MSE of the performance of data-moderate assessment methods for U.S. West Coast groundfish Chantell Wetzel Data-Moderate STAR Panel April 23-28, 2013

  2. Outline • Description of Assessment Models • DCAC, DB-SRA, exDB-SRA, and exSSS (AIS) • MSE Simulation Setup • Operating model • Projection Period • Results • Rockfish • Cases 1, 3, and 6 • Flatfish • Cases 1, 3, and 6

  3. Description of Models • exDB-SRA • Data: Index of Abundance • Delay-Difference Model • Knife-edged selectivity set at age of maturity for fishery & survey • Parameters: • M, Fmsy/M, Delta fixed year ( = 1-depletion), Bmsy/B0 • Estimates B0 • Results: Stochastic* • DB-SRA • Parameters: • M, Fmsy/M, Delta fixed year (=1-depletion), Bmsy/B0 • Results: Stochastic • exSSS • Data: Index of Abundance • Age-Structured • Knife-edged selectivity set at age of maturity for fishery & survey • Parameters • M, steepness, depletion in a fixed year • Estimates R0 • Results: Deterministic • DCAC • Parameters: • M, Fmsy/M, Delta fixed year (=1-depletion), Bmsy/B0 • Results: Stochastic

  4. Operating Model • Age-Structured Operating Model • Two Life-History Types • Flatfish • Rockfish • Recruitment • Shepherd’s Stock Recruit Relationship • Process Error: Recruitment Deviations • Single Fishery • Begins in year 1 with the operating model population in non-equilibrium • Single Survey • Observation Error • CV = 0.25

  5. Simulation Setup Population Setup Projection Period Age-Structured Operating Model Recruitment: Shepherd’s SRR Year 1:50 Conduct Assessment Index of Abundance Year 31:50 Fishery Year 1-50 Estimate OFLs Index of Abundance Year 31:(50 +4 years) Reduce to ABCs End of Projection: Year 75 Evaluate Performance of Each Assessment Method Operating Model Project Forward 4 years

  6. Adaptive Importance Sampling • Create initial parameter sets • Fix parameters in the assessment model and solve for R0 or B0 that meets the final depletion value under the assumed dynamics. • Sample from the initial parameter set based on the weights: • Regenerate parameter vectors using a multivariate student’s T distribution based on the drawn parameters • Rerun the assessment model with each of the new parameter sets • Repeat steps 2-4 until the entropy criteria (e > 0.92)is met: • Create a large final sample from the parameter sets that met the entropy criterion. • Run the assessment model for the final time with the final parameter sets.

  7. Preliminary Results

  8. Rockfish Case 1: where all priors are assumed correctly and biomass is at target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  9. Rockfish: Case 1OFL estimation

  10. Status in Year 75

  11. Rockfish: Case 1 Relative Error of Spawning Biomass exDB-SRA exSSS RE Spawning Biomass RE Spawning Biomass Year Year

  12. exDB-SRA exSSS

  13. RockfishCase 3: where all priors are assumed correctly and biomass is below target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  14. Rockfish: Case 3 OFLs

  15. Status in Year 75

  16. Rockfish: Case 3 Relative Error of Spawning Biomass exDB-SRA exSSS RE Spawning Biomass RE Spawning Biomass Year Year

  17. exDB-SRA exSSS

  18. RockfishCase 6: where productivity and status in year 50 are mis-specified, biomass is below target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  19. Rockfish: Case 6 OFLs

  20. Status in Year 75

  21. Rockfish: Case 6 Relative Error of Spawning Biomass exDB-SRA exSSS RE Spawning Biomass RE Spawning Biomass Year Year

  22. exDB-SRA exSSS

  23. FlatfishCase 1: where all priors are assumed correctly and biomass is at target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  24. Flatfish: Case 1OFL estimation

  25. Status in Year 75

  26. Flatfish: Case 1 Relative Error of Spawning Biomass exDB-SRA exSSS

  27. exDB-SRA exSSS (AIS)

  28. FlatfishCase 3: where all priors are assumed correctly and biomass is below target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  29. Flatfish: Case 3 OFLs

  30. Status in Year 75

  31. Flatfish: Case 3 Relative Error of Spawning Biomass exDB-SRA exSSS

  32. exDB-SRA exSSS

  33. FlatfishCase 6: where productivity and status in year 50 are mis-specified, biomass is below target depletion Time-trajectories of depletion for the rockfish population when the OFLs are provided by each assessment method

  34. Flatfish: Case 6 OFLs

  35. Status in Year 75

  36. Flatfish: Case 6 Relative Error of Spawning Biomass exDB-SRA exSSS

  37. exDB-SRA exSSS

  38. Conclusions • There are some advantages of exDB-SRA and exSSS over the data-limited methods; DCAC and DB-SRA • Mis-specifications • exDB-SRA generally performs better for the rockfish life-history compared to flatfish • exSSS rebuilds both life-histories towards or above the target quickly

More Related