Evaluations of the Nordmore grid and secondary bycatch-reducing devices (BRD's) in the Hunter River prawn-trawl fishery, Australia

Several bycatch-reducing devices (BRD's) were compared for their effectiveness in reducing bycatch while maintaining catches of prawns in an estuarine prawn-trawl fishery in New South Wales (NSW), Australia. A solid separator-panel (the Nordmore grid), a soft separator panel (the commercially used blubber chute), and four secondary BRD's (the fisheye, extended mesh funnel, Allerio Brothers grid, and square-mesh panel) each attached to a Nordmore grid, were compared against each other in a series of paired comparisons in the Hunter River prawn-trawl fishery. The results showed that the Nordmore grid and all secondary BRD's caught less bycatch and more prawns than the commercially used blubber chute. Most bycatch seemed to escape with use of the Nordmore grid, and there was no significant advantage in adding a secondary BRD to this design. The efficiency of the Nordmore grid has led to its voluntary adoption by many commercial prawn-trawl fishermen throughout NSW estuaries.