Coral reefs in every ocean basin have now been affected by bleaching-level heat stress, marking the fourth global bleaching event on record and the most extensive yet. Monitoring data show that 54% of reef area has been exposed to temperatures high enough to cause widespread bleaching.
Marine ecologists say that the frequency of such events leaves reefs little time to recover between episodes. "We are seeing reefs bleach that have never bleached before," says Femi Adeyemi, a reef ecologist at the Pacific Institute for Ocean Research.
Scientists are calling for rapid emissions cuts alongside local measures, such as improved water quality, that can help reefs withstand heat stress.
