A netting-based alternative to rigid sorting grids in the small-meshed Norway pout (Trisopterus esmarkii) trawl fishery

摘要: A new bycatch reduction device, termed "Excluder", is presented as an alternative to a traditional rigid sorting grid, mandatory in the small-meshed Norway Pout (Trisopterus esmarkii) trawl fishery North Sea. The high-volume with large vessels, demersal trawls and catches up 100 tons per haul of this small forage fish. Excluder 30 m long netting-based system, developed reduce (70 mm square meshes) improving on board gear-handling safety. was tested against 5.8 m2 standard grid (35 bar spacing) twin-trawl experiment from commercial 70 trawler "S364 Rockall". Catch data were analysed by species length using catch comparison method. For all analysed, had significantly lower relative grid: herring (21%), whiting (6%), mackerel (5%), American plaice (70%), witch flounder (15%), lesser silver smelt (71%). there significant increase overall efficiency 32%. These results are explained 10 cm smaller L50 (the fish 50% probability being rejected system) 15 times larger area, which reduces risk clogging loss function. With these documented effects improved target efficiency, implementation would improve sustainability address two main barriers current pout that limit quota capitalization; tendency for mix lowered rates grid-clogging. Additionally, safety be improved.