A socio-psychological approach for understanding and managing bycatch in small-scale fisheries

Fisheries bycatch is the greatest threat to migratory, long-lived marine animals. Managing bycatch can be particularly problematic in small-scale mixed-species fisheries, where perceptions of target and non-target vary widely, and all catches have economic or subsistence value. Such fisheries are ubiquitous throughout the world’s oceans, and represent a cross-disciplinary challenge for biodiversity, food security and livelihoods. We offer a novel approach for addressing this challenge, drawing on well-established theories from behavioural and social sciences. We first typify bycatch as a spectrum rather than a clearly delineated component of catch, where the position of a species on this spectrum depends on fishers’ beliefs regarding the outcomes of bycatch-relevant behaviour. We then outline an approach to diagnose the underlying socio-psychological drivers of bycatch, based on the Theory of Planned Behaviour. Finally, we illustrate the approach using an empirical case study, exploring fishers’ beliefs regarding bycatch-relevant behaviour for three endangered species in a small-scale gill net fishery in Indonesia. We show how a socio-psychological approach can help to identify conflicts and synergies between bycatch mitigation and fishers’ beliefs, thus informing more effective and socially-just interventions for marine megafauna conservation. We emphasize the need to understand human dimensions of bycatch, especially in SSFs, where technical fixes alone will be insufficient to change behaviour. Rather, interdisciplinary approaches are needed to align fishers’ needs with conservation objectives. Our spectrum and approach could be widely applied for disentangling drivers of bycatch in other SSFs, and designing interventions which support effective and equitable marine conservation.