Reconnecting reef recovery in a world of coral bleaching

Abstract

Coral bleaching can have widespread impacts on reefs leaving many areas in need of coral recovery. While the long-term mitigation of bleaching requires transitioning to a low carbon economy, local management has focused on approaches that seek refugia from or tolerance to bleaching stressors, reduce additional stressors, or facilitate coral recovery. Here, we describe a tactical response to coral bleaching events that seeks to identify the most important reefs for driving imminent recovery. A bleaching recovery algorithm is described that identifies those reefs that provide the most important sources of coral larvae that supply many reefs in the early stages of post-bleaching recovery (i.e., reefs in need of coral larval supply). We describe the algorithm with a simple toy example and then apply it to the Great Barrier Reef, which has experienced three mass bleaching events in the last 5 yr. Once such reefs have been identified it makes practical sense to undertake a vulnerability assessment and if necessary reduce manageable stressors, such as outbreaks of crown-of-thorns starfish or anchor damage, so that critical sources of coral recovery are not depleted further. In short, algorithms like this can help managers target finite management resources, including restoration, to where they might be most effective in facilitating natural processes of recovery.