Refining a simple anterior fish excluder (SAFE) for penaeid trawls

Abstract Following recent international efforts to assess anterior modifications to trawls as a means for precluding unwanted catches, a promising device termed the ‘simple anterior fish excluder’ (SAFE) was modified for an Australian penaeid-trawl fishery. We tested a conventional penaeid trawl against those rigged with two SAFEs; each comprising a plastic banner located between the otter boards but orientated as either single- (original design) or double-concave configurations. Compared to the conventional trawl, both SAFEs caught significantly fewer absolute and standardised (ha –1 trawled) numbers of the most abundant non-target species, southern herring ( Herklotsichthys castelnaui ), although mean reductions were greater in the trawls with the double-concave (by 59 and 50%) than single-concave (44 and 36%) SAFE. Neither absolute nor standardised catches of the targeted school prawns ( Metapenaeus macleayi ) were affected. The results reiterate the generic utility of anterior modifications for reducing bycatch and maintaining function across different geometries. Configuring the SAFE as a double concave did partially improve its efficiency, but it also complicated fishing operations. Therefore, we conclude that owing to its simplicity, the single-concave design might be a preferable configuration for penaeid-trawl fisheries—pending assessments of other refinements.