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

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

3. North Sea cod – Outline Data –Stock area –Catch data –Survey data –Stock distribution –Value estimates –Sampling and observer coverage –Biological data Assessment Advice

4. North Sea cod – stock area

5. North Sea cod – official landings

6. North Sea cod – Int. effort TR1 = Trawl gear with mesh ≥ 100mm

7. North Sea cod – Int. effort TR2 = Trawl gear with mesh ≥ 70mm & < 100mm

8. North Sea cod – Int. effort GN = Gill nets & entangling nets

9. Reg. gear2011 TR168.8% TR211.6% GN10.8% BT25.2% BT11.6% GT1.3% LL0.7% TR3V small % North Sea cod – Int. cod catch

10. North Sea cod – catches 2011 Removals = 67 kt Landings = 35 kt (52%), discards = 11.7 kt (17%), unaccounted = 20.3 kt Unaccounted Discards Landings

11. North Sea cod – surveys Available surveys: –IBTS Q1 1983-2012 –IBTS Q3 1991-2011 –ScoGFS Q3 1982-2011 –EngGFS Q3 1992-2011 –North Sea Commission Fishers’ Survey Only IBTS Q1 used in assessment –Possible changes in catchability in Q3 –Fishers’ Survey not quantitative

12. North Sea cod – surveys IBTS Q1 2008 age 1 2009 age 1 2010 age 12011 age 1 2012 age 1 2008 age 2 2009 age 2 2010 age 22011 age 2 2012 age 2 2008 age 3+ 2009 age 3+ 2010 age 3+2011 age 3+ 2012 age 3+

13. North Sea cod – surveys IBTS Q1

14. North Sea cod – surveys North Sea Commission Fishers’ Survey 2011

15. North Sea cod – modelled abundance distribution

21. North Sea cod – VMS-based landings distribution

26. North Sea cod – observer coverage 2011 FleetDeclared landings (tonnes) Number of trips sampled Discard weight (tonnes) Discard rate All1050539341424.5% TR1 (whitefish) 1022828252919.8% TR2 (Nephrops) 2221188579.9%

27. North Sea cod – observer coverage 2011

30. North Sea cod – port sampling coverage 2011 FleetDeclared landings (tonnes) Number of trips Number of trips sampled Number of fish measured Number of otoliths taken All10773518039102054546

31. North Sea cod – mean weight-at- age in catches Age 1 Age 2 Age 3 Age 4 Age 5 Age 6 Age 7 Age 8 Age 9

32. North Sea cod – natural mortality estimates

33. North Sea cod – maturity estimates

34. North Sea cod – assessment Assessed using the SAM method –Includes IBTS Q1 survey, landings, discards –Landings and discards from 1993-2011 are scaled by an estimated parameter –Indicates unaccounted removals SAM is a robust approach and is increasingly widely used at ICES –SAM: NS cod, western Baltic plaice, NS sole, Kattegat cod, NS herring –TSA: Cod VIa, haddock VIa

35. North Sea cod – assessment

36. F mp

37. North Sea cod – assessment

38. Removals

39. North Sea cod – assessment Removals multiplier

40. North Sea cod – forecasts & advice (June 2012) Reduce F in steps from 2008 onwards: –2009 F = 75% 2008 F –2010 F = 65% 2008 F –2011 F = 55% 2008 F –And so on… Most recent estimate of 2008 F used at each step. Apply sliding-F rule: Management plan has two phases: Blim Bpa #1 used until suggested TAC is lower than that from #2, or F = 0.4 for three years

41. North Sea cod – forecasts & advice (June 2012) For both management plan phases: –Maximum effort reduced in line with F (but with bycatch rules). –± 20% constraint on annual quota changes. –Forecasts based on estimate total removals, which are then split into: Landings (quota). Discards. Unaccounted removals. Other Articles relevant also, e.g.: –Article 9: data-poor situations. –Article 10: different approach if recovery not working. –Article 13: derogations to reduce effort cuts.

42. North Sea cod – forecasts & advice (June 2012) MSY: –F(msy) MSY framework: –F’ = F(msy) * SSB(2012) / B(pa) MSY transition rule: –More gradual shift to F(msy) Zero catch Roll-over landings [Mixed-fisheries advice]

43. North Sea cod – forecasts & advice (June 2012) Two versions of advice depending on intermediate year (2012) assumptions: –Table A: management plan followed in 2012, giving 18% reduction in F. –Table B: recent trend in F continues, giving 12% reduction in F. ICES recommends Table B.

44. North Sea cod – forecasts & advice (June 2012) RationaleBasisF total 2013 Landings 2013 Discards 2013 Unalloc 2013 SSB 2014 dSSBdTAC Management plan TAC cons. 0.2625.46.58.6107+37%-20% Table A: (note 2012 TAC = 31.8)

45. North Sea cod – forecasts & advice (June 2012) RationaleBasisF total 2013 Landings 2013 Discards 2013 Unalloc 2013 SSB 2014 dSSBdTAC Management plan TAC cons. 0.2725.46.68.6103+36%-20% MSYF msy 0.19194.96.4112+47%-41% MSY framework F’0.10102.53.4123+63%-69% MSY transition Rule0.29287.29.4101+33%-13% Zero catchF = 00.0000.0 136+80%-100% Rollover landings Landi ngs 2012 0.494311.514.682+8%+34% Table B: (note 2012 TAC = 31.8)

46. West of Scotland cod See next file…

47. North Sea cod – TR1 value maps

51. North Sea cod – TR2 value maps

55. Future developments – CCTV estimates of discard rates Work progressing on discard-rate estimation Potentially a very important data source Several current limitations: –Resources (equipment and staff) –Methodology –Quality of data

56. Future developments – CCTV estimates of discard rates

57. Work progressing on discard-rate estimation Potentially a very important data source Several current limitations: –Resources (equipment and staff) –Methodology –Quality of data Hope to maintain cameras at least for scientific observation

58. Future developments – draft management area proposals