The Great Barrier Reef, the largest coral structure on Earth, is suffering from what may be its worst bleaching event ever recorded.
But according to new research, future bleaching events could be even worse and may disable a natural protection mechanism of the reef's corals - leaving them more defenseless against warmer seas.

http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=11623562