Heat-evolved microalgal symbionts increase coral bleaching tolerance

Coral reefs worldwide are suffering mass mortalities from marine heat waves. With the aim of enhancing coral bleaching tolerance, we evolved 10 clonal strains of common coral microalgal endosymbiont at elevated temperatures (31 degree celsius) for 4 years in the laboratory. Coral populations globally have deteriorated over the past two to three decades due to climate change related marine heat waves.