Towards the Light: Reducing mobuild bycatch in small-scale fisheries using light

Mobulid ray fisheries are largely unregulated and unreported. Global landings increased by an order of magnitude from 1998-2009, with bycatch forming a major component. The devil rays (Mobula spp.) are charismatic migratory... [ view full abstract ]

Mobulid ray fisheries are largely unregulated and unreported. Global landings increased by an order of magnitude from 1998-2009, with bycatch forming a major component. The devil rays (Mobula spp.) are charismatic migratory species with circumglobal ranges. Members of the genus are vulnerable to extinction, and listed under several multilateral environmental agreements, including the Convention on Migratory Species and the Convention on International Trade in Endangered Species of Wild Fauna and Flora. While mobulid conservation and management efforts have achieved notable successes worldwide, they have predominantly focused on target fisheries and the illegal wildlife trade. The significant issue of bycatch, particularly within widespread small-scale fisheries, remains largely overlooked.   

We present preliminary results from a randomized control trial to evaluate the technical, social and economic feasibility of using light to reduce mobulid bycatch within Indonesia’s small-scale drifting gillnet fisheries. Our findings suggest that installing devices that emit specific wavelengths has the potential to reduce mobulid bycatch and to maintain or enhance target catches. However, stated preferences revealed via choice modelling highlight the urgent need to strengthen regulatory frameworks and to leverage market forces in order to create the incentives that will drive small-scale fisheries to adopt technologies and practices that enhance sustainability.