This report documents a global analysis designed to help
illuminate the distribution and condition of oyster reefs, which have been among the most important and valuable resources to humans and among the most poorly understood as a habitat. Numerous recent papers document the condition of and threats to marine ecosystems globally, but most of these estimates of the condition of marine ecosystems are indirect and based on the distribution of assumed threats (e.g., trawling, sedimentation, pollution). Shellfish declines have been considered in part by others; however, they did not directly estimate ecosystem condition except in a few places.