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Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea Shale Rosen, Terje Jörgensen and Arill Engås Insitute of Marine Research Postboks 1870.

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Presentation on theme: "Pelagic Trawling for Cod, Haddock and Saithe in the Barents Sea Shale Rosen, Terje Jörgensen and Arill Engås Insitute of Marine Research Postboks 1870."— Presentation transcript:

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2 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

3 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

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

5 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

6 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)

7 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

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

9 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 cod end cover cod end

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

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

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

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

14 Comparisons With Demersal Trawls

15 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)

16 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

17 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

18 Acknowledgements The Fishery and Aquaculture Industry Research Fund

19 Questions?


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