A new study has found while many coral reefs in the Pacific are suffering some are thriving.
Called "A framework for identifying and characterising coral reef 'oases' against a backdrop of degradation," it identified 38 coral oases in the Pacific last year.
One of the lead authors is Peter Edmunds from California State University.
Dr Edmunds said these coral sanctuaries have been categorised as escape, rebound and resist oases.
He explained that escape oases are coral communities which have been able to avoid disasters such as bleaching, invasions by coral-eating starfish and hurricanes.
In comparison resist oases are corals that appear hardy and able to resist environmental challenges, and rebound oases are coral reefs that have suffered damage but have recovered.
Dr Edmunds said one promising area is Hawaii, where he said since a coral bleaching crisis in 2015, some of the reefs have now stabilised.