Marine Protected Areas: Design & Effectiveness

Marine protected areas (MPAs) are geographically defined ocean zones where human activities are regulated to conserve biodiversity. As of 2025, roughly 8 percent of the global ocean falls within some form of MPA designation, though only a fraction qualifies as fully or highly protected. The push toward the 30x30 target — protecting 30 percent of the ocean by 2030 — has accelerated MPA creation worldwide. Understanding how MPAs work, and when they fail, is essential for anyone studying marine conservation.