Equitable pathways for sustainable tuna fisheries management in the Indian Ocean

Sustainability in fisheries hinges upon a multifaceted approach. It entails an ongoing assessment of fisheries' sustainability across ecological, social, and economic dimensions. This necessitates a comprehensive understanding of the trade-offs inherent in pursuing these diverse goals. Within the Indian Ocean, tuna fisheries management faces challenges due to unsustainable exploitation, uneven access to catch opportunities, and increasing stakeholder tensions. To address some of these challenges and respond to the expressed need for science-based management, our integrated approach combines a stock assessment operating model, several management scenarios used for decadal projections and the resulting inequality metrics across fishing fleets. The application focuses on yellowfin tuna (Thunnus albacares), which is the most vulnerable species in the Indian Ocean, targeted equally by both industrial and artisanal fleets. The study explores management options, including restrictions on DFAD (drifting fish aggregating device) sets, operational buoys, seasonal closures, and complete DFAD elimination. Results suggest that DFAD-free and seasonal closures effectively rebuild yellowfin tuna biomass but may also lead to increased inequality, either in catch or revenue distributional terms. Reducing DFAD fishing during the third quarter redistributes fishing opportunities more equitably. The findings underscore the need for effective DFAD control and emphasise considering distributional aspects in tuna fisheries management.