Coral bleaching

Coral bleaching is the paling or whitening of corals due to a loss or decline of the symbiotic microalgae (zooxanthellae) that live within the coral polyp, and that give it colour. Coral bleaching is caused by both natural and human-induced variations in the reef environment. Some causes of coral bleaching include changes in water temperature, sub-aerial exposure caused by low tides or ENSO-related changes in sea level and rapid dilution of salinity levels.