Read here.
"So death is not the corals’ only response to change. The ability of corals to shuffle symbionts is an effective adaptive strategy for dealing with environmental changes, such as changes water temperatures and light levels...Add these two studies to a growing case file in support of the resiliency (rather than the fragility) of Nature. While coral bleaching appears to be mass suicide to uninformed senators, it could actually be an excellent adaptive strategy that has allowed the species to survive for millions of years."
