The world's coral reefs are going through the most intense bleaching event ever recorded, with 84% of them now affected, scientific authorities announced on Wednesday.
The current crisis, the fourth global bleaching event since 1998, is more intense than the 2014-17 episode that caused some two-thirds of global reefs to experience the harmful whitening.
Coral bleaching occurs when the colorful algae that live within corals and feed them begin to produce toxins as a result of warming waters, causing their hosts to expel them. This exposes the corals to a greatly increased risk of disease and starvation.