SYDNEY, March 17 (Xinhua) -- Australia's Great Barrier Reef has been suffering a worsening coral bleaching caused by global warming, according to a new survey published Wednesday in the journal Nature.
Using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures, researchers found that in 2016, more than 60 percent of reefs experienced extreme bleaching, which was over four times higher than the figure in 1998 or 2002.
"In 2016, only 8.9 percent of 1,156 surveyed reefs escaped with no bleaching, compared to 42.4 percent of 631 reefs in 2002 and 44.7 percent of 638 in 1998," said the survey.
Since the 1980s, rising sea surface temperatures owing to global warming have triggered unprecedented mass bleaching of corals covering almost the entire Great Barrier Reef Marine Park in 1998, 2010, 2015 and 2016 respectively.
Coral bleaching is a process in which coral colonies lose their vivid color, which happens when the water is too warm for the microscopic algae living in the organisms.
Bleached corals are physiologically damaged, and sustained bleaching will lead to coral death.
Greenpeace released on March 10 photos and footage of widespread bleaching of corals between Port Douglas and Cairns that they claimed "were full of color and life" just months ago.