Submitted Ideas

What is the full extent of the global coral reef crisis?

Posted by Elizabeth Madin | New South Wales, Australia

Coral reefs are struggling in many areas of the world due to overfishing, pollution, climate change, and other stressors. Despite the best efforts of scientists and conservation practitioners to assess and quantify these declines, how the total amount of coral reef area, or “reef structure”, is changing remains unknown. Reef structure is important as fish habitat and as a foundation upon which new corals can grow. In a recent perspective paper we published in the journal Conservation Biology, we argue that an accurate assessment of the condition of coral reefs globally will require combining estimates of local ecological change with broad-scale estimates of how much reef structure actually exists. It’s important to have this full global picture so that we can establish a baseline of how much coral area actually exists in the world, then in future years check to see if and how much this is changing. Knowing how it is changing will give us a more accurate picture than we can currently have of how coral reefs globally are doing. In addition to current monitoring of what's living on top of the reef structure, starting to monitor the actual amount of coral reef area using modern technology will give us a barometer for global changes in this valuable resource. Satellite imagery is now of such high spatial resolution and relatively low cost that we have an unprecedented opportunity to harness this power to create a first-ever baseline of global reef area against which future changes can be assessed.