Harmful bleaching of the world’s coral has grown to include 84% of the ocean’s reefs in the most intense event of its kind in recorded history, the International Coral Reef Initiative announced Wednesday.

Coral reefs have long been losing their color due to bleaching, but a recent uptick has caused nearly all of the world's reefs to be damaged. A record-breaking amount of marine life fell victim to the bleaching, and scientists say the effects may be irreversible.