Simultaneous coral bleaching on the Great Barrier Reef and Ningaloo Reef

Australia's two largest coral reefs, the Great Barrier Reef and Ningaloo Reef, are affected by coral bleaching at the same time. The unusually high water temperatures are severely affecting sensitive ecosystems. A scientist warns that this must be a “wake-up call” to take urgent action to protect the reefs.

Dead corals in shallow water that were damaged during the mass coral bleaching event. Source: Moment RF / Sirachai Arunrugstichai/Getty Images