The Australian Great Barrier Reef has again faded widely, for the third time in five years. That says the Great Barrier Reef Marine Park Authority (GBRMPA), which manages the site.
The authority said on Thursday that warmer sea temperatures, especially in February, have caused a large loss of coral.
The Great Barrier Reef is located off the northeastern Australian coast and is the largest coral system in the world. Several mass bleaching has been reported in 2016 and 2017, with an estimated one third to half of the corals dying.
The GBRMPA says that aerial observations show that certain southern areas of the reef that barely or never faded in 2016 and 2017 did now. Major tourist reefs in the northern and central parts of the reef have faded only to a limited extent, and most corals will recover there.
Not all bleached corals die, but the chance is greater in heavily bleached reefs.