To protect corals from summer heatwaves, we should help their microbial symbionts evolve heat tolerance in the lab

Most coral reef restoration efforts involve restocking reefs with nursery-grown corals. However, if these corals are of the same stock as their wild counterparts, they will be equally vulnerable to the heat stress that caused the bleaching event in the first place. Researchers discuss the potential of improving corals' chances by inducing the evolution of heat tolerance in their symbionts -- the mutualistic microbes that provide corals with nutrients in exchange for shelter and that are expelled during coral bleaching.