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Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea

Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea. Shale Rosen, Terje J örgensen and Arill Engås Insitute of Marine Research Postboks 1870 Nordnes N-5817 Bergen Norway shale.rosen@imr.no. Nor-Fishing Technology Conference 2008 Trondheim, Norway 11-12 August 2008. Overview.

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Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea

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  1. Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea Shale Rosen, Terje Jörgensen and Arill Engås Insitute of Marine Research Postboks 1870 Nordnes N-5817 Bergen Norway shale.rosen@imr.no Nor-Fishing Technology Conference 2008 Trondheim, Norway 11-12 August 2008

  2. Overview • Glossary • Introduction to project, objectives • 1960s-1970s pelagic trawl fishery • Why the renewed Interest? • Data collection • Catches • Comparison with demersal trawl catches • Conclusions • Next steps

  3. Glossary Pelagic Trawl = Midwater Trawl = Flytetrål Demersal Trawl = Bottom Trawl = Bunntrål Cod = Torsk = Gadus morhua Haddock = Hyse = Melanogrammus aeglefinus Saithe = Sei = Pollachius virens Images Northeast Fishery Science Center www.nefsc.noaa.gov

  4. Introduction to Project • Test pelagic fishery for species typically caught in demersal trawls • Research Topics: • Availability of cod, haddock, saithe to pelagic trawls • Selectivity of pelagic trawls • Behaviour as trawl approaches and once inside • Development of pelagic trawl to target cod, haddock, saithe

  5. 1960s-1970s Pelagic Trawl Fishery • Spring fishery for cod and haddock off northern tip of Noway, late summer fishery for haddock farther offshore • Closed 1979 due to reports of high bycatch of juveniles (higher than in demersal trawls)

  6. Why the Renewed Interest? • Impacts of demersal trawls on seabed • Reduce bycatch of highly demersal species (eg. flatfish) • Reduce fuel consumption • Sorting grids and larger mesh proven successful in other trawl fisheries

  7. 15 meters 60 meters 7 meters 40 meters 262 meters Data Collection, Net and Sensors

  8. cod end cod end cover Data Collection (cont.) • Distance between doors and height relative to headrope and footrope • Amount of towing wire and tension • Catch in grid cover, cod end, and cod end cover grid cover

  9. Catch Locations and Vertical Distribution, Cod April 2008 cruise, pelagic cod area

  10. X X Catches in Pelagic Trawl Total: 175 tons 50% in just 3 hauls!

  11. 42 cm, Minimum Legal Size 47 cm, Minimum Legal Size Length Distributions of Catch Few undersized fish encountered, removed by sorting grid

  12. Length Distributions of Catch: Comparison with Demersal Trawl Larger cod captured in cod end of pelagic trawl mean 81 cm = 5 kg mean 75 cm = 4 kg

  13. Comparisons With Demersal Trawls

  14. Image Injector Trawldoors A/S Conclusions- Gear • Opening of 40 m by 60 m was well-sized for the distributions and behaviour we encountered. • Benthic trawl doors spread net adequately and made it easy to switch between pelagic and demersal trawls • 300mm liner in belly may not be necessary (at most 9 fish meshed per haul)

  15. Conclusions- General • In the right conditions, pelagic trawl is a highly effective way of catching cod (150 tons in 5 days) • Most effective during brightest daylight hours • Sorting grid effectively removed small gadoids and pelagics (herring and blue whiting) • Cod caught in pelagic trawl were larger than in demersal trawl • CPUE higher in pelagic trawl than demersal trawl, when pelagic distributions were present • Fuel consumption between that of single and twin demersal trawl • Not a replacement for demersal trawls, but pelagic trawls may increase fleet’s flexibility and reduce seabed impact for each portion of quota caught without using demersal trawl

  16. Next Steps • October cruise on R/V, focused on behaviour and selectivity studies • Spring 2009 cruise on F/T, focused on use in commercial fishery • Discussions with Fisheries Directorate about authorizing an experimental fishery with data collection • We anticipate continued cooperation with net manufacturers and fishermen to refine design for selective and efficient pelagic trawls for gadoids

  17. The Fishery and Aquaculture Industry Research Fund Acknowledgements

  18. Questions?

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