SlideServe
Télécharger Obtenir Pro
Menu
Accueil Pro
Préférences
ApparenceLight Aide et commentaires
© SlideServe · v2026

Status of NE Fishery Resources & Related Science Issues

chessa avatar
chessa
82 diapositives · 993 Views · Sep 14, 2014

This overview presents key findings on the status of major fish stocks in New England, especially in Georges Bank and the Gulf of Maine. It explores the scientific basis for biomass goals, including shifts in baselines and recruitment indices, alongside spatial patterns in fishing effort, the role of Marine Protected Areas (MPAs), and adaptive management strategies. Additionally, it addresses ecosystem-level issues, predator-prey dynamics, and knowledge gaps, emphasizing the importance of understanding the ecological benefits of MPAs and their impact on fishery resilience and recovery.

#status of ne fishery resources & related science issues #status of ne fishery resources & related science issues ppt #powerpoint #presentation
Status of NE Fishery Resources & Related Science Issues - slide 1
01 / 82Status of NE Fishery Resources & Related Science Issues
1 / 17

Télécharger la présentation

Status of NE Fishery Resources & Related Science Issues
Une image / un lien ci-dessous est fourni (tel quel) pour télécharger la présentation

Politique de téléchargement : le contenu du site vous est fourni TEL QUEL pour votre information et votre usage personnel ; il ne peut être vendu, concédé sous licence ni partagé sur d’autres sites sans l’accord de son auteur.Le contenu vous est fourni TEL QUEL, pour votre information et votre usage personnel uniquement. Téléchargez la présentation en cliquant sur ce lien. Lors du téléchargement, si vous ne parvenez pas à télécharger une présentation, l’éditeur a peut-être supprimé le fichier de son serveur.Pendant le téléchargement, si vous ne parvenez pas à obtenir une présentation, le fichier a peut-être été supprimé par l’éditeur.

F I N

Plus de contenu associé

Transcription de la présentation

  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

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

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

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

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

  8. Bmsy=217 k Fmsy=0.18

  9. Bmsy = 83 k Fmsy=0.23

  10. Bmsy = 59 k Fmsy = 0.25

  11. Bmsy = 45 k Fmsy = 0.27

  12. Survey Documents Recovery of Depleted Fishery Stocks

  13. Barndoor Skate – back from the dead… Goal

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

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

  16. 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

  17. Can this be Done in Reality?

  18. Atlantic Sea Scallop

  19. Sessile Success! Scallop Fishermen GB Survey

  20. 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

  21. 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”

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

  23. Are habitat gradients confounding the interpretation?

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

  25. 2003 VMS Positions For speed > 3.5 kn Mos. 1-10

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

  27. 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

  28. “Footprint Analyses”

  29. 2001-2003 Autumn Spring

  30. 2001-2003 Autumn Spring

  31. Inside Outside

  32. Area closed

  33. “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)

  34. Effects of Closures on Groundfishes Otter Trawl fleet

  35. 4000+ Observed Trawl Tows 2001- 2002