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DISSOSTICHUS SP.

Antarctica's White Gold - the Ecology and Management of Toothfish in the Southern Ocean Dr Mark Belchier (BAS). DISSOSTICHUS SP. Two species ( D. eleginoides & D. mawsoni ) Members of the family Nototheniidae Large predators/scavengers No swim bladder Great depth range.

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DISSOSTICHUS SP.

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  1. Antarctica's White Gold - the Ecology and Management of Toothfish in the Southern OceanDr Mark Belchier (BAS)

  2. DISSOSTICHUS SP. • Two species (D. eleginoides & D. mawsoni) • Members of the family Nototheniidae • Large predators/scavengers • No swim bladder • Great depth range

  3. PATAGONIAN TOOTHFISH (D. eleginoides)

  4. DISTRIBUTION • Circumpolar • Continental slope • 100 >2000m depth • Juveniles over shelf • Cold water • D. mawsoni south of 60o D. eleginoides distribution

  5. POPULATIONS D. eleginoides in the S. Atlantic

  6. GENERAL BIOLOGY • Max size >220cm (100kg+) • Long-lived (>50 years) • Deeper = larger • Slow swimming • High lipid content

  7. Martialia hyadesi FEEDING ECOLOGY • Scavenger/predator • Prey items include fish, cephalopods, molluscs, crustaceans • Small fish eaten by juveniles • Few predators (Weddell seals, Giant squid ?)

  8. GROWTH

  9. Life Cycle Life cycle of D. eleginoides at South Georgia

  10. Recruitment Survey LF series of juveniles at South Georgia

  11. FISHERY • Developed late ’80s off Chile • Mostly longline • Deepwater • Multinational (FAO- Fishstat data)

  12. MANAGEMENT • All fisheries south of APF regulated by CCAMLR • National management of EEZ’s

  13. CCAMLR • Commission for the Conservation of Antarctic Marine Living Resources • Ratified April 1982 • Part of Antarctic treaty system • 24 members (including EU) • Annual meeting in Hobart, Tasmania

  14. THE CONVENTION A) prevention of decrease in the size of any harvested population to levels belowthose which ensure its stable recruitment. B) maintenance of the ecological relationships between harvested, dependent andrelated populations of Antarctic marine living resources and the restoration ofdepleted populations to the levels defined in sub-paragraph (a) above; and • prevention of changes or minimization of the risk of changes in the marine ecosystem which are not potentially reversible over two or three decades = an ecosystem approach to management

  15. HOW IS THIS UNDERTAKEN ?South Georgia case study • South Georgia lies within CCAMLR area • Declared 200nm Maritime Zone in 1992 (GSGSSI) • International (CCAMLR) and National (GSGSSIMZ) management regimes • First longline fishery in 1991/92 (Chilean) • Largest Toothfish fishery in CCAMLR area

  16. THE SOUTH GEORGIA FISHERY

  17. South Georgia Toothfish Fishery- Management Regime • Highly conservative stock assessments (CCAMLR) • Rigorous reporting of fishery data (GSGSSI) • Scientific data collection (Scientific observers etc) • Bycatch mitigation measures • Fishery protection vessels • Catch documentation scheme (CDS) • Inspection and Enforcement

  18. STOCK ASSESSMENTS • Assessed annually by CCAMLR (WG-FSA) • ‘CASAL’ used for fully integrated assessment - allows management under uncertainty. • Yield (TAC) determined by explicit ‘Decision Rules’ governing depletion. • Long- term projections (35 years)

  19. Data Collection • Observers on all toothfish vessels for all fishing period • Annual groundfish surveys • Reliable catch , effort and landing data reported to CCAMLR and GSGSSI • Scientific studies carried out at sea (Tagging etc) • Validated , accurate age date (BAS , KEP) • Continual updating of assessment model (CCAMLR , Imperial College)

  20. IMPACT OF THE FISHERY • Incidental mortality of seabirds • Bycatch (vertebrate and invertebrate) • Seabed disturbance by longlines (impact on benthos)

  21. Incidental mortality of seabirds Has been a huge problem – now solved (in legal fisheries)

  22. Seabird Bycatch Mitigation • Seasonal closure (winter only) • Streamer lines • Bait thawing • Night setting • No discarding of offal • Line weighting • New technology

  23. Assessments and mitigation (spatial/gear) BYCATCH

  24. BENTHOS MPAs the way forward?

  25. IS MANAGEMENT WORKING? • Stable TAC (3000 – 4000 tonnes). • Stable CPUE (Slight increase over past 5 years). • Massive reduction in seabird mortality (0 birds in 2008). • ‘TAC’s’ for by-catch species never taken. • MSC certification • However…………………..

  26. THE THREAT OF IUUIllegal, Unreported and Unregulated – ‘Pirate’ • Big problem in some CCAMLR areas • >50% catch in some areas (PEI) • Mitigated by patrols – costs are high • CDS • Public education Viarsa – caught and sunk !

  27. http://www.antarctica.ac.uk/ http://www.sgisland.org

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