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. Addressing bycatch ultimately requires changing fisher behaviour, yet social and behavioural sciences are rarely applied to bycatch mitigation, with an absence of theory-informed behaviour change interventions. Moreover, mitigating bycatch is particularly challenging in small-scale mixed-species fisheries (SSFs), 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 bycatch mitigation in these contexts necessitates a people-centred approach. We seek to address this gap, 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' fishers' underlying beliefs about bycatch, using the theory of planned behaviour (TPB): a widely applied and empirically tested theory for predicting and changing behaviour. Finally, we illustrate the approach using an empirical case study, exploring fishers' beliefs regarding bycatch-relevant behaviour for three endangered elasmobranch species in a small-scale gill net fishery in Indonesia. Our findings show how the TPB can help to understand fishers' underlying beliefs regarding bycatch, and facilitators/inhibitors of bycatch mitigation, to inform behaviour change interventions. We emphasize the need to understand the 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 bycatch spectrum and the TPB could be widely applied for disentangling drivers of bycatch in other SSFs and designing interventions which support more effective and socially just marine conservation.