Status of NE Fishery Resources & Related Science Issues

1. Status of NE Fishery Resources & Related Science Issues

2. Overview • Status of major stocks (esp. GB & GOM) • Scientific Basis for Biomass Goals (a case of shifting baselines?) • Spatial Patterns of Effort & Distribution & effectiveness of MPAs • Ecosystem-level issues, adaptive management, and knowledge gaps

3. Numerous ecosystem considerations : Predator/prey, competition

8. B-MSY=250 kmt F40% = 0.26

9. Juvenile Haddock in Scallop Dredge Survey Tows Summer, 2003

11. Fall Trawl Survey-Haddock Recruitment Indices, 1963-2003

14. mean wind stress vectors (mid-March to mid-May) 1995, 1999, 2002 and 2003. (NOAA Buoy 44008) by D. Mountain

16. Bmsy=217 k Fmsy=0.18

17. Bmsy = 83 k Fmsy=0.23

18. Bmsy = 59 k Fmsy = 0.25

19. Bmsy = 45 k Fmsy = 0.27

21. Survey Documents Recovery of Depleted Fishery Stocks

23. Barndoor Skate – back from the dead… Goal

24. Georges Bank Haddock – Defining a biomass target outside the historic baseline 2003 = 125 kmt!

25. GB Haddock – SSB / R using modern growth data

27. How was the New Biomass target for Georges Bank Haddock Computed? Bmsy = mean recruitment when SSB > 75,000 mt = 68.9 million times spawning biomass per animal at F = 0.263 = 3.63 kg = 250 thousand metric tons

28. Can this be Done in Reality?

29. Atlantic Sea Scallop

34. Sessile Success! Scallop Fishermen GB Survey

35. Three Main Biological Effects of MPAs • “Reserve Effects” = higher density in closed areas, demographic shifts, reproductive output increased, potentially resulting in: • “Spill Over” = net movement out of adults (apart from ontogenetic or other non-density related movements) • A Really Big Question: Is there a “Fatal Attraction” of fishing effort to reserve boundaries, seeking spillover? • “ Export” = net export of larvae or juveniles to open areas • Fisheries benefit from permanently closed areas via Spillover, Export, or overall reductions in fishing rate

36. Spatial Management & MPAs • New England fishery closed areas: a 9 year + case • study in temperate waters (5 pseudo-replicates) • Previous work (2000) demonstrated “reserve effects” especially for sea scallop and other benthics • Seasonal movements and depth distributions of many • target species means that cross-boundary excursions are frequent • Are the MPAs providing benefits to conservation • of groundfish resources, & the fishery, and what can we learn about movement & dispersion? approaches: • Differential densities (in/out) • Potential for “spillover”

37. “Rolling Closures” In addition to Year-round closures June May April Oct- Nov. March May

38. Are habitat gradients confounding the interpretation?

39. pixel is 1’ lat by 1’ long 2003 Revised 2003 VMS Positions For speed </= 3.5 kn Mos. 1-12 Multispecies (groundfish) Trawlers movie…

40. 2003 VMS Positions For speed > 3.5 kn Mos. 1-10

41. Trawler Effort Patterns 1991-1993 10’ squares w/1/4 degree Proration of some data

42. Requirements for “Spillover” • Pressure Head • (differential densities in/out) • High Velocity at “Spillway” • (velocity and volume dissipate • w/distance) • Test for Spillover is 2-part: • First, is there a density • differential (in/out)? then: • Density vs. distance from edge

43. “Footprint Analyses”

44. 2001-2003 Autumn Spring

45. 2001-2003 Autumn Spring

46. Inside Outside

47. Area closed

48. “Proximity Analyses” • R/V Data too sparse for tests of “spill over” • Fortunately, fishermen have been conducting this experiment for us • adjust commercial trawler catches for effort species targeting, etc. & Calibrate • Sea Sampling in New England increased in recent years because of court order (7,000+ tows in 2003)

49. Effects of Closures on Groundfishes Otter Trawl fleet

50. 4000+ Observed Trawl Tows 2001- 2002