High take of mobulid rays in East Java, Indonesia: landing trends and socio-economic context

Mobulid rays (genus Mobula) comprise ten species of highly threatened filter-feeding rays, seven of which occur in Indonesia and five of which are caught in small-scale fisheries off Muncar, East Java. We conducted a study in Muncar from 2015 to 2024 to assess mobulid ray catch composition, trends in mobulid ray catch rate, demography, and the socio-economic context of their fisheries through fish market surveys (n = 1467) and interviews with fishers (n = 30), fish collectors (n = 4), and processors (n = 15). The study shows that mobulid rays are at high risk from target and bycatch in Muncar and are mainly caught in drift gillnets. A declining trend in the catch rate of M. mobular, compounded by mobulid ray declines reported by fishers, and a majority of immature specimens across Muncar’s fisheries indicate that mobulid rays are likely overfished in East Java. Illegal landings of M. birostris and M. alfredi, and evidence of mobulid gill plate trade intended for international exportation highlight an urgent need for better enforcement of existing national protections and international conservation provisions. This study highlights a critical need for improved conservation of all mobulid ray species in Indonesia given their high extinction risk and the unsustainable fishing pressure they face. This will require swift enforcement of CITES through better trade control, improved protective legislation, and fisheries management for all mobulid ray species, with measures targeted toward local fisheries characteristics and socio-economic context.