A ‘Simple Anterior Fish Excluder’ (SAFE) for Mitigating Penaeid-Trawl Bycatch

Abstract

<div><p>Various plastic strips and sheets (termed ‘simple anterior fish excluders’−SAFEs) were positioned across the openings of penaeid trawls in attempts at reducing the unwanted bycatches of small teleosts. Initially, three SAFEs (a single wire without, and with small and large plastic panels) were compared against a control (no SAFE) on paired beam trawls. All SAFEs maintained targeted <i>Metapenaeus macleayi</i> catches, while the largest plastic SAFE significantly reduced total bycatch by 51% and the numbers of <i>Pomatomus saltatrix</i>, <i>Mugil cephalus</i> and <i>Herklotsichthys castelnaui</i> by up to 58%. A redesigned SAFE (‘continuous plastic’) was subsequently tested (against a control) on paired otter trawls, significantly reducing total bycatch by 28% and <i>P</i>. <i>saltatrix</i> and <i>H</i>. <i>castelnaui</i> by up to 42%. The continuous-plastic SAFE also significantly reduced <i>M</i>. <i>macleayi</i> catches by ~7%, but this was explained by ~5% less wing-end spread, and could be simply negated through otter-board refinement. Further work is required to refine the tested SAFEs, and to quantify species-specific escape mechanisms. Nevertheless, the SAFE concept might represent an effective approach for improving penaeid-trawl selectivity.</p></div