Effects of management objectives and rules on marine conservation outcomes.

Understanding the relative effectiveness and enabling conditions of different area-based management tools is essential for supporting efforts that achieve positive biodiversity outcomes as area-based conservation coverage increases to meet newly set international targets. We used data from a coastal social-ecological monitoring program in six Indo-Pacific countries to analyze whether social, ecological, and economic objectives and specific management rules (temporal closures, fishing gear-, species-specific restrictions) were associated with coral reef fish biomass above sustainable yield levels across different types of area-based management tools (i.e., comparing those designated as marine protected areas (MPAs) to other types of area-based management). We found that all categories of objectives, multiple combinations of rules, and all types of area-based management had some sites that were able to sustain high levels of reef fish biomass - a key measure for coral reef health - compared to reference sites with no area-based management. Yet the same management types also had sites with low biomass. As governments advance their commitments to the Kunming-Montreal Global Biodiversity Framework and the target to conserve 30% of the planet's land and oceans by 2030, we show that while different types of management can be effective, most of the managed areas in our study regions did not meet IUCN criteria for effectiveness. These findings underscore the importance of strong management and governance of managed areas, and the need to measure the ecological impact of area-based management rather than counting areas because of their designation. This article is protected by copyright. All rights reserved.