A sustainable seafood network to conserve mobulid rays thresher and hammerhead sharks

Muhammad Ghozaly Salim

Indonesia is the world’s largest shark and ray fishing nation, many of which are endangered. In the Bali Strait, mobulid rays, thresher and hammerhead sharks are caught as bycatch in non-selective gillnets. Their catch per unit effort is low, yet overall catch is a concern due to many boats operating from Muncar port. Previous data shows that releasing mobulid rays alive from gillnets after capture can lead to high survival, as the duration of gillnet deployment in this artisanal fishery is relatively short. Furthermore, the proportion of revenues from fisheries versus tourism sectors differs greatly across Muncar (East Java) and Bali, yet geographical proximity offers an opportunity to direct funds towards conservation. Considering the catch of gillnet fishers in Muncar is dominated by small to medium-sized bony fish, a rich source of protein, we propose to support the creation of a sustainable seafood network by (1) training existing fishing cooperatives to release elasmobranchs alive from nets, (2) link these cooperatives to additional market chains that will increase the value of target fish assemblages, focusing on lower food chain species to promote sustainability, and (3) measure the effectiveness of this model and provide recommendations for improving, upscaling and replicating it elsewhere.