Conflict with industrial fleets undermines the contributions of small-scale fisheries to sustainable development in vulnerable regions.

Equitable and sustainable governance of small-scale fisheries (SSFs) is essential for achieving food security and conservation in coastal areas. Yet in increasingly industrialized oceans, competition and conflict with large-scale fisheries (LSFs) threaten the contributions of SSFs to the United Nations Sustainable Development Goals. Here we have developed a small-scale and industrial fisheries interaction index and applied it to 126 countries using 2 recent global datasets. Vulnerability to conflict is highest in countries where SSFs are vital for nutrition, but governance is weak, especially in Africa, Oceania and Asia. We also identify low-exposure outlier countries with unexpectedly low risk of SSF-LSF interactions, providing insights for proactive policy. Preferential access areas granting spatial rights to SSFs are common in both low- and high-vulnerability countries, suggesting such policies are often reactive and may be insufficient alone without strong enforcement. As ocean industries expand, it will be necessary to strengthen SSF access rights and limit LSF overcapacity to reduce conflict and advance sustainable development.