Efficacy of Time-Area Fishing Restrictions and Gear-Switching as Solutions for Reducing Seabird Bycatch in Gillnet Fisheries

Despite the global scale of gillnet bycatch, universal measures that effectively reduce bycatch of seabirds in gillnets have not been found. Bycatch in coastal gillnet fisheries is an ongoing threat for several seabird species. Strategies to reduce seabird bycatch in gillnet fisheries were evaluated, focusing on the effectiveness of time-area fishing restrictions and gear-switching to meet seabird conservation objectives, ensure fisher acceptance, and avoid unintended consequences. A review of case studies showed that variations in the spatial and temporal distributions of target and non-target species may cause a mismatch between time-area regulations and high bycatch, but consideration of bycatch species behavior can help define effective fine-scale spatial and temporal measures. The potential for meeting conservation objectives through gear-switching is promising, with some further development needed for successful application. Combining measures (e.g., time-area fishing restrictions, gear-switching, visual and acoustic deterrents) may be feasible in some regions, if fine-scale spatial and temporal information about the overlap of seabirds and gillnet gear is available. A holistic approach to reduce seabird bycatch in gillnets, including understanding of seabird biology, habitat preference, and feeding ecology combined with information about fishing activity, target species, and socioeconomic impacts provides a framework to develop mitigation measures.