Successful fisher-driven reduction of megafauna bycatch in a tuna gillnet fishery

Bycatch in gillnet fisheries is a major source of marine megafauna mortality but effective mitigation options remain limited, especially in low-income countries. Technical solutions developed for industrial fleets are often too costly or impractical for these fisheries, while regulatory measures demand substantial monitoring and enforcement capacity. Collaborative solutions that harness fisher innovation and social networks remain underexplored and underfinanced. Controlling for key factors affecting bycatch risk, we used Generalized Additive Models to quantify the performance of 13 tuna gillnet captains participating in a fisher engagement program in Pakistan from 2012-2016. A co-developed subsurface net setting strategy, combined with bycatch awareness training and peer-learning, coincided with substantial reductions in dolphin and sea turtle bycatch. Although gillnets are widely viewed as simple, unselective, and universally high-risk gears, we found significant variation among individual captains’ bycatch rates, even as the group improved remarkably over time through iterative changes in fishing practices and accumulated fisher experience. This variation indicates that, beyond known factors such as fishing location, season, and gear configuration, individual fishers employ nuanced and adaptive tactics that strongly influence bycatch outcomes. Encouragingly, reductions in bycatch did not come at the expense of target catch, suggesting that improved selectivity and profitability can be aligned. These findings highlight the need for fisher-led bycatch interventions that acknowledge individual variation and actively leverage fishers’ capacity to adapt their practices to fish more selectively.