Great Barrier Reef experiencing one of its worst coral bleaching events

Australia’s Great Barrier Reef is experiencing one of its worst bleaching events since monitoring began nearly four decades ago, authorities say, with much of the famed reef showing signs of damage as warming ocean temperatures blight reefs worldwide.

Bleaching occurs when heat-stressed coral turn white after expelling symbiotic algae that provide food and color. It’s a result of abnormal ocean temperatures in the past year that scientists worry could represent a major change to Earth systems.