Uncovering Bright Spots Among the World’s Coral Reefs

Ongoing declines among the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently untapped approach that draws on theory and practice in human health and rural development is systematically identifying and learning from the ‘outliers’- places where ecosystems are substantially better ('bright spots') or worse ('dark spots') than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here, we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We then identified 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that had biomass levels more than two standard deviations from expectations. Importantly, bright spots were not simply comprised of remote areas with low fishing pressure- they include localities where human populations and use of ecosystems resources is high, potentially providing novel insights into how communities have successfully confronted strong drivers of change. Alternatively, dark spots were not necessarily the sites with the lowest absolute biomass and even included some remote, inhabited locations often considered near-pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots were characterised by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Our results suggest that investments that strengthen fisheries governance, particularly issues such as participation and property rights, could help communities to innovate in ways that allow them to defy expectations.