Abstract
Global fisheries support livelihoods, food security and economies, but the incidental capture of non‐target species—termed bycatch—remains a key conservation challenge. We compiled peer‐reviewed published studies to assess metrics used to evaluate the effectiveness of bycatch reduction technologies and gear modifications (BRTs) for reducing air‐breathing marine megafauna bycatch in global passive fisheries. We assessed 196 studies, including assessments in operational fisheries and controlled experiments, from 114 published articles between 1997 and 2024. These studies tested 28 types of BRTs across five fishing gears. Changes in bycatch and target catch were assessed in 94.4% and 73% of all studies, respectively. By contrast, only 6.6% of studies assessed catch value. We identified and evaluated seven fisher‐focused metrics that were divided into quantitative and anecdotal evidence describing how the application of BRTs affects fishers. Relative to quantitative assessments, 9.2% of all studies quantified effects on fishing gear, 8.7% quantified BRT cost, 4.1% quantified economic impact, 3.1% quantified fisher safety, 3.1% quantified BRT ease of use, 2% quantified operational efficiency and 1% quantified fisher perceptions of BRT efficacy. Relative to anecdotal evidence, 10.7% of all studies reported on ease of use, 7.1% on BRT cost, 6.6% on fisher perceptions of efficacy, 3.1% on effects on fishing gear, 1.5% on effects on fisher safety and 0.5% on both operational efficiency and economic impact. Across diverse regions and timeframes, our analysis highlights a persistent lack of fisher‐focused metrics in BRT research, emphasising the need for more holistic evaluations that consider fisher wellbeing.