A large part of the Great Barrier Reef off the east coast of Australia, the world's largest coral reef, has lost its colours.
In a statement made by the Great Barrier Reef Marine Park Authority (GBRMPA), it was stated that this was the worst case of mass bleaching ever seen on the reef.
Rising sea temperatures have created an underwater heat wave in the coral reef.
Warmer water causes corals to expel the colorful algae that live in their tissues. Corals cannot survive without the help of algae, which provide nutrients to the corals.
Earlier this week, the US weather service NOAA announced that we are currently witnessing a global mass dawning event.
This means there is significant bleaching of reefs in both the Atlantic, Pacific and Indian Oceans.