Coral bleaching occurs when corals are stressed by changes in environmental conditions, such as increased water temperatures. This stress causes the corals to expel the algae living in their tissues, turning them white or pale. Without the algae, the corals lose their main source of food and become more susceptible to disease and death.
A nearly two-year-long study of Hawaiian corals suggests some species may be better equipped to handle warmer, more acidic waters than previously believed.
As the world sees rising ocean temperatures, it will also see more cases of coral bleaching. When corals bleach, they become more vulnerable to other stressors such as water pollution.