Scientists are warning that one of the seven wonders of the natural world is at risk of serious damage. They say more than 90 percent of Australia's Great Barrier Reef has experienced coral bleaching.
Researchers say the problem is caused by rising water temperatures. They first noticed the phenomenon at the World Heritage site in the 1980s, but they say it has escalated recently.
A survey by the Australian government and a research body found bleaching at 93 percent of 911 individual reefs. The damage was most extreme in the northern 1,000-kilometer stretch of the system. One researcher warned the bleaching could affect almost all of the coral species. He said some could take decades or longer to recover.
UNESCO considered putting the Great Barrier Reef on its "World Heritage in Danger" list last year, but it dropped the plan after the Australian government submitted a conservation plan.
◆reef 礁
◆coral bleaching さんごの白化（現象）
◆research body 研究機関
