Gear trials in Skagerrak A “new” pelagic grid SLU Aqua Joakim Hjelm, Andreas Sundelöf, Daniel Velentinsson, Hans Nilsson, Mikael Ovegård, Anders Wernbo SPFPO, Carmona GG 330 Swedish University of Agricultural Sciences www.slu.se
The problem • During Q3 saithe is pelagic in Skagerrak • Hence, there is bycatch of saithe in herring fishery (Aug-Sept) • No specific quota for saithe in the Swedish pelagic system Swedish University of Agricultural Sciences www.slu.se
Conditions • The SPFPO contacted SLU • Grids in pelagic gear have been used in blue whiting and Norway pout fisheries in Faeroe Islands and Norway • Not extensively tested or evaluated in other fisheries • Gear trials supported by Swedish Agency for Marine and Water Management (SWaM) and the Ministry. Swedish University of Agricultural Sciences www.slu.se
Gear trials The light and camera • Not possible to have a double set of trawls • Camera used for observations/quantitative evaluation • 4 weeks of experimental work in Aug-Sept 2015 on-board GG330 Carmona Swedish University of Agricultural Sciences www.slu.se
A possible solution Schematic presentation grid with a protective sheet Grid Light and camera Codend Front of trawl Protective sheet Swedish University of Agricultural Sciences www.slu.se
Setting up the Saithe grid Swedish University of Agricultural Sciences www.slu.se
Initial trials • Cameras; finding the angle and position of cameras for good footage • Grid set up; angle and position Objectives • Minimize saithe bycatch • Minimize loss of herring Swedish University of Agricultural Sciences www.slu.se
Results - general Swedish University of Agricultural Sciences www.slu.se
Results according to objectives Catch of Saithe Herring Loss of Herring Saithe Haul # Saith (t) bycatch Catch (t) Herring (t) loss % catch (t) calculated (%) Film Film Film 7 65 1.74 2.7 0.37 7.32 5.0 12 70 3.68 5.3 0.24 3.71 6.5 13 36 5.39 15.0 0.22 2.79 7.9 14 40 2.96 7.4 0.20 2.55 7.8 15 30 2.88 9.6 0.16 3.90 4.1 Swedish University of Agricultural Sciences www.slu.se
Schematic presentation grid without a protective sheet Grid Light and camera Codend Front of trawl Swedish University of Agricultural Sciences www.slu.se
Swedish University of Agricultural Sciences www.slu.se
Implications of a saithe grid • Few vessels fish during day-time during Q3 – i.e. substantial unwanted catch • Grid reduces unwanted catch of saithe with 92-96% – 25-75 kg Saithe/h during trials observed Way forward • Look into fish behaviour inside the trawl • How to set up the grid (new material), position and angle Swedish University of Agricultural Sciences www.slu.se
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