Both the value and plight of corals reefs are well established. During the past five decades, researchers have identified the key problems affecting reefs, including sedimentation, pollution, overfishing and climate change. We have also documented extensive losses, with an estimated 50% of reefs having been severely impacted during this period, as a result of human activities. Some reefs are thriving and have demonstrated the capacity for recovery from both local and global level stressors. Others have passed a tipping point and reached an alternate stable state, dominated by algae, and are unlikely to recover without interventions.