1. George Bank Cod Base –Similar to GARM2005 assessment Fleet_dome Survey_dome Survey_and_Fleet_dome Purpose: test models ability to estimate correctly when doming occurs

2. GB cod basic setup Years 1978-2005 (27 years) Ages 1-25, 10+ Lengths 1-170 cm 3 market categories 3 surveys (CVs 20%, 30%, 25%) CV on landings 5% Growth stdevs 5.0 initial, 2.0 projection Von B params 148.2, 0.1198, -0.6173 50% Mature ~42 cm Selectivity flat-topped, 50% selected 64 cm M = 0.2 F high (0.5-2.4) then reduced in final years (0.48, 0.35)

3. GB cod test cases Fleet_dome –Moved ascending limb of selectivity curve left to allow for nearly full selectivity at peak of dome

4. GB cod test cases Survey_dome –Each survey mirrored for descending limb of selectivity curve at age 7

5. Georges Bank Cod BASEFleet Dome Survey Dome Fleet&Surv. Dome AIM SSB: strong bias F: -40% to+20% ASPICOne way trip problem SCALE SSB: 5-30% + F: ~30% - VPA SSB: slightly + F: slightly - ASAP SSB: slightly + F: slightly -

6. AIM Issues with low (or no) sampling in some years

7. Georges Bank Cod BASEFleet Dome Survey Dome Fleet&Surv. Dome AIM SSB: strong bias F: -40% to+20% Division by zero problem ASPICOne way trip problem SCALE SSB: 5-30% + F: ~30% - VPA SSB: slightly + F: slightly - ASAP SSB: slightly + F: slightly -

8. Georges Bank Cod BASEFleet Dome Survey Dome Fleet&Surv. Dome AIM SSB: strong bias F: -40% to+20% Division by zero problem ASPICOne way trip problem SCALE SSB: 5-30% + F: ~30% - Low simulated length sampling obscured the effect we were testing for VPA SSB: slightly + F: slightly - ASAP SSB: slightly + F: slightly -

9. SCALE Issues with very low sampling in some years

10. Georges Bank Cod BASEFleet Dome Survey Dome Fleet&Surv. Dome AIM SSB: strong bias F: -40% to+20% Division by zero problem ASPICOne way trip problem SCALE SSB: 5-30% + F: ~30% - Low simulated length sampling obscured the effect we were testing for VPA SSB: slightly + F: slightly - slightly - slightly + Same as base (‘E.coast way’) Same as “Fleet Dome” ASAP SSB: slightly + F: slightly -

11. VPA (SSB) Poor performance for ages>6

12. VPA (FAA) Poor performance for ages>6

13. Georges Bank Cod BASEFleet Dome Survey Dome Fleet&Surv. Dome AIM SSB: strong bias F: -40% to+20% Division by zero problem ASPICOne way trip problem SCALE SSB: 5-30% + F: ~30% - Low simulated length sampling obscured the effect we were testing for VPA SSB: slightly + F: slightly - slightly - slightly + Same as base (‘E.coast way’) Same as “Fleet Dome” ASAP SSB: slightly + F: slightly - slightly - Same as base (‘E.coast way’) Same as “Fleet Dome”

14. ASAP

15. VPA vs ASAP (NAA)

17. Precision (SSB and F) AIM: ~ 0.1, did not vary by case SCALE: 0.2-0.5 (increased with retros) VPA*: 0.05-0.4 (poor ages>6), did not vary ASAP: <0.05, did not vary *VPA CVs are for age-specific SSB, F

18. GB Cod Conclusions Simulation set-up precluded model comparisons for AIM, ASPIC, and SCALE Between VPA and ASAP, bias was similar, but VPA estimates at age degraded faster than ASAP; ASAP more precise Dome not an issue for survey because of age- specific indices (rather than age comp. for total N index) Dome effect in fleet probably minimized because of large simulated F (fewer older fish, so misspecifying those selectivities added little bias)

19. VPA PR BaseFleet Dome 2002 2003 2004

20. VPA Fleet Dome Retro

21. VPA q “East Coast Style” Survey DomeBase