The Great Barrier Reef is currently experiencing a huge, and unprecedented , coral bleaching event, caused by climate change.

"Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef," convener of Australia's National Coral Bleaching Taskforce, Terry Hughes, told BuzzFeed News regarding his most recent expedition to the reef in March.

"We flew for 4000km in the most pristine parts of the Great Barrier Reef and saw only four reefs that had no bleaching. The severity is much greater than in earlier bleaching events in 2002 or 1998."