Reefs at Risk Revisited is a high-resolution update of the original global analysis, Reefs at Risk: A Map-Based Indicator of Threats to the World’s Coral Reefs. Reefs at Risk Revisited uses a global map of coral reefs at 500-m resolution, which is 64 times more detailed than the 4-km resolution map used in the 1998 analysis, and benefits from improvements in many global data sets used to evaluate threats to reefs (most threat data are at 1 km resolution, which is 16 times more detailed than those used in the 1998 analysis).
This paper highlights the seriousness of the “biodiversity crisis” on atolls and the need to place greater research and conservation emphasis on atolls and other small island ecosystems. It is based on studies over the past twenty years conducted in the atolls of Tuvalu, Tokelau, Kiribati, the Marshall Islands and the Tuamotu Archipelago of French Polynesia. It stresses that atolls offer some of the greatest opportunities for integrated studies of simplified small-island ecosystems.