coral bleaching ?

[jmack]

What does it mean when a coral bleaches out white (ie, is it dead, in the process of dying or sick possibly just sick)?

[theatrus]

All of the above really. It may still be living, but may not survive much longer.

[TippyToeX]

Any one of those. The coral (depending on which kind) could have expelled it's zooxanthellae causing it to appear white/bleached. It could also be that the tissue has sloughed off exposing the skeleton.

[PVitty77]

Just read the answer to that question in Bornemans book, Aquarium corals. TippytoeX is right. its just the coral doing what it feels it needs to do to survive.