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The Cod Day - Science

The Cod Day - Science. Coby Needle, Nick Bailey, Rui Catarino, Steven Holmes Marine Laboratory Aberdeen. Outline. North Sea cod West of Scotland cod Future developments. WoS cod – stock area. WoS cod – official landings. WoS cod – catches. 2011 Removals = 6.36 kt

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The Cod Day - Science

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  1. The Cod Day - Science Coby Needle, Nick Bailey, Rui Catarino, Steven Holmes Marine Laboratory Aberdeen The Cod Day Marine Laboratory, Aberdeen, 2 October 2012

  2. Outline • North Sea cod • West of Scotland cod • Future developments

  3. WoS cod – stock area

  4. WoS cod – official landings

  5. WoS cod – catches 2011 Removals = 6.36 kt Landings = 0.52 kt (8%), discards = 5.84 kt (92%)

  6. WoS cod – surveys • Available surveys: • ScoGFS-WIBTS-Q1: 1985–2010 • Became UKSGFS-WIBTS-Q1 in 2011 • ScoGFS-WIBTS-Q4: 1996-2009 • Became UKSGFS-WIBTS-Q4 in 2011 • IGFS-WIBTS-Q4 • Only ScoGFS-WIBTS-Q1 used in assessment • 2013 assessment: Too soon to use UKSGFS (& stock subject to 1.5% bycatch rule).

  7. WoS cod – surveys

  8. WoS cod – surveys

  9. WoS cod – surveys Q4 2010 Q4 2011

  10. WoS cod – Int. effort TR1 = Trawl gear with mesh ≥ 100mm

  11. WoS cod – Int. effort TR2 = Trawl gear with mesh ≥ 70mm & < 100mm

  12. WoS cod – Int. effort LL = Long Lines

  13. WoS cod – Int. effort GN = Gill nets & entangling nets

  14. WoS cod – Int. cod catch

  15. WoS – TR1 landings COD HADDOCK ANGLER SAITHE

  16. WoS – TR1 & TR2 landings WHITING NEPHROPS

  17. WoS cod – observer coverage 2011

  18. WoS cod – port sampling coverage 2011

  19. WoS cod – mean weight-at-age in catches

  20. WoS cod – natural mortality estimates

  21. WoS cod – assessment • Assessed using the TSA method • Includes ScoGFS-WIBTS-Q1 survey, landings & discards • Landings 1995-2005 not used (suspected as biased) • No survey data for 2011-2012. • TSA - same basic approach as SAM model but developed in house (Rob Fryer)

  22. WoS cod – assessment

  23. WoS cod – assessment

  24. WoS cod – assessment

  25. WoS cod mortality – lnds vs dis

  26. WoS cod – assessment

  27. WoS cod – area misreporting

  28. Unlike N Sea F reduction only related to previous year Reduction depends on prediction of SSB at start of TAC year: 25% reduction in F if SSB < Blim 15% reduction in F if Blim < SSB < Bpa Min(10% reduction in F or F=0.4) if SSB > Bpa But 20% limit to changes in TAC But But 25% TAC reduction if stock unhealthy yet ‘data poor’ Also – ICES has never accepted management plan as precautionary WoS cod – Management plan

  29. MSY approach MSY framework: TAC = 30 t MSY transition: TAC = 270 t But because SSB << Blim advice was for zero catch WoS cod – Advice

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