How the Spread of Young Coral Can Help Save Coral Reefs

Coral reefs around the world are getting sick (and sometimes dying) at alarming rates due to climate change. Certain coral reefs (low-risk reefs) are predicted to be less at risk of getting sick than others. We wondered whether low-risk reefs can help save other reefs. We found that this is possible—through the movement of young coral from healthy reefs to damaged or dying reefs. We found that coral reefs worldwide are connected through the spread of young coral, forming 604 reef networks. Some networks are very large, but most are very small. If only the low-risk coral reefs survive, many of these networks will be preserved, which will help the overall survival of coral reefs into the future. However, young coral from these low-risk reefs do not reach all reefs worldwide, so it is important to find and protect reefs that are good at sending young coral to rescue the rest of the world’s reefs.