What is coral bleaching
Bleaching occurs when stressed corals release algae that provide them with vital nutrients. That algae also gives the coral its color, so when it's expelled, the coral turns white.
Coral reefs are vital around the world as they not only provide a habitat for fish — the base of the marine food chain — but food and medicine for humans. They also create an essential shoreline barrier that breaks apart large ocean swells and protects densely populated shorelines from storm surges during hurricanes.