Protecting Earth's last conservation frontier: scientific, management and legal priorities for MPAs beyond national boundaries

Abstract Marine areas beyond national jurisdiction (ABNJ) comprise most of Earth's interconnected ocean, hosting complex ecosystems that play key roles in sustaining life and providing important goods and services. Although ABNJ encompass nearly half the planet's surface, biological diversity found in these areas remains largely unprotected. Mounting pressures generated by the escalation of human activities in ABNJ threaten vital ecosystem services and the fragile web of life that supports them. Marine protected areas (MPAs) are widely acknowledged as an important tool for the conservation of biological diversity. Currently less than 1% of ABNJ are protected, with the vast majority of MPAs located in waters within national jurisdiction. The existing legal framework for protection and sustainable use of ABNJ lacks common…