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 [email protected]

Nor-Fishing Technology Conference 2008 Trondheim, Norway 11-12 August 2008

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

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

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

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)

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

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

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 cod end cover

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

Catches in Pelagic Trawl

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Catch per Haul, Cod Total: 175 tons

50 22 21 21 17 16 10 6 5 2 0

1 Catch, tons 50% in just 3 hauls!

Catch by Time of Day, Cod

90 80 40 30 20 70 60 50 10 0 X X 22:00 02:00 01:59 05:59 06:00 09:59 10:00 13:59

Time of day

14:00 17:59 18:00 21:59

Length Distributions of Catch

Few undersized fish encountered, removed by sorting grid

Length Distributions, Cod

5% 4% 3%

47 cm, Minimum Legal Size

2% 1% 0% 45 55 65 75 85

Fish length (cm)

95 105 115 Codend Grid Cover Codend Cover 15% 10% 5% 0% 35

Length Distributions, Haddock 42 cm, Minimum Legal Size

40 45

Fish length (cm)

50 55 Codend Grid Cover Codend Cover

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

Comparisons With Demersal Trawls

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) Image Injector Trawldoors A/S

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 trawl ’s flexibility and reduce seabed impact for each portion of quota caught without using demersal

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

Acknowledgements

The Fishery and Aquaculture Industry Research Fund

Questions?