The Great Barrier Reef is in danger as 93 percent of it suffers from coral bleaching, a comprehensive reef survey has shown.
A few weeks ago, an aerial survey conducted by Professor Terry Hughes of the National Coral Bleaching Taskforce in Australia showed that the northern part of the reef has high levels of bleaching. It is the most untouched area yet the most affected, with 81 percent of its 522 reefs fried.
Professor Andrew Baird of the Centre of Excellence for Coral Reef Studies reported that the latest underwater and aerial survey already showed the northern portion of the reef has 50 percent coral mortality.
Worsening climate change, particularly El Niño, has been causing the bleaching of the reefs. Hughes further explained that if temperatures continue to drop in the coming months, 90 percent of the corals in the north can die. However, he also expressed hope that the corals can recover.
Hughes pointed out that in two mass coral bleaching incidents that occurred in 1998 and 2002, 40 percent of the reefs survived bleaching, with only 18 percent severely fried. But this time is much worse - it is as if 10 cyclones hit simultaneously.
"By that metric, this event is five times stronger," Hughes said. "This time it's 55 percent."
Continued study of the southern portion and underwater areas showed that only 7 percent or 68 reefs of the entire Great Barrier Reef remain unaffected by coral bleaching.
Federal Environment Minister Greg Hunt has acknowledged that the extent of the coral bleaching of the Great Barrier Reef is the worst bleaching ever recorded. The surveyed area, encompassing 2,300 kilometers (1,429 miles) including 911 reefs, was varied and patchy but still very significant.
The extent of coral bleaching in the Great Barrier Reef has threatened its world heritage status. Last year, the World Heritage Committee excluded the reef on its "in danger" list, basing its decision on a federal report that said the northern area is unaffected.
Hunt shared that his office is updating the committee on the status of the coral bleaching event, including their comprehensive monitoring response. Hunt also cited the government's long-term Reef 2050 plan to address environmental issues.