The world's rainbow reefs have gone ghostly white in seas around the globe due to record heat in the oceans, the International Coral Reef Initiative reports. But scientists say the reefs aren't all dead yet and could still bounce back if people take the right steps.

The most severe global coral bleaching event ever recorded is underway, with most of the world's reefs hit by damaging heat stress, according to scientists. The devastating bleaching has affected 84% of the world's reefs,