Australia's Great Barrier Reef coral bleaching worsens

It is estimated that 2/3rd of coral coverage died in a 700 km stretch of reef north of Port Douglas

The coral bleaching situation in Australia's Great Barrier Reef has worsened due to widespread damages caused by warmer ocean temperatures, a media report said on Friday.

The first survey for 2017 was conducted on Thursday by the Great Barrier Reef Marine Park Authority (GBRMPA), over the area between Cairns and Townsville in Queensland state.

The agency's David Wachenfeld said that had given him enough information to "regrettably" confirm another mass bleaching occurred.

"We also have quite a few reports through our early warning system, the eye on the reef program," Wachenfeld told the Australian Broadcasting Corporation on Friday.

Warmer water temperatures resulted in the widespread bleaching of large areas of coral in the northern reef last year.

Scientists estimated that two-thirds of coral coverage died in a 700 km stretch of the reef north of Port Douglas.

However, Wachenfeld said it was too soon to know how this year's bleaching event compared to that seen last year.

Surveys over the rest of the reef will be conducted in the next two weeks.

Bleaching occurs when warm waters prompt coral to expel algae living within their tissues, turning white. the Guardian daily reported.

The coral may die in the six to 12 months after bleaching, meaning the level of mortality on the reef will not be determined until later in the year.

The world heritage-list reef was spared an "in danger" listing by Unesco in 2015 but environmental groups argue it remains on the organisation's "watch list".