Global Reef Study Finds Under 2% of the Ocean Sits Inside MPAs Showing Real Fish Biomass Recovery

A global synthesis of underwater biodiversity data from thousands of shallow coral and rocky reefs, published September 7, 2026 by Ella Clausius, a postdoctoral reef ecologist at the University of Tasmania, found that while roughly 10% of the ocean now carries official 'protected' status, less than 2% lies within marine protected areas actually showing measured fish-biomass recovery. The 2% figure already assumes full compliance with fishing rules inside protected zones — real-world enforcement is patchier, so the researchers say the effectively protected share is likely smaller still. The study argues that paper designations are a poor proxy for ecological outcomes and calls for direct underwater monitoring of fish biomass, rather than protection status alone, to track whether MPAs are delivering genuine recovery.