Warm sea temperatures bleach reef off Australia

The Great Barrier Reef off the east coast of Australia is in the midst of the worst bleaching event scientists have ever observed. Aerial surveys conducted by the National Coral Bleaching Taskforce, a group of more than 300 scientists from 10 research institutions across Australia, show that a 4,000 km stretch of the most pristine part of the reef is experiencing severe bleaching caused by warming sea temperatures. Increased temperatures lead to a loss of tiny photosynthetic algae called zooxanthellae, which live in coral. Without the algae, coral turn white and often die.