"Australian authorities said Sunday coral bleaching occurring in the World Heritage-listed Great Barrier Reef had become "severe", the highest alert level, as sea temperatures warm.

Australian Environment Minister Greg Hunt said while the bleaching at this stage was not as severe as in 1998 and 2002, also El Nino-related events, "it is however, in the northern parts a cause for concern".

"The reef is 2,300 kilometres (1,429 miles) long and the bottom three-quarters is in strong condition, but as we head north, it becomes increasingly prone to bleaching," Hunt said after an aerial tour of some of the affected areas Sunday, the Australian Broadcasting Corporation reported."

AFP had the story March 20, 2016. [2]

SEE ALSO:

"Is Climate Change Cooking Our Coral Reefs?" (Pacific Standard) [3]

"Corals Are Dying on the Great Barrier Reef" (National Geographic) [4]

"Climate Change Warnings For Coral Reef May Have Come To Pass, Scientists Say" (Guardian) [5]