Hot water is killing Florida's coral reefs. But it's not the only factor bleaching them white.
Corals are tiny animals that live in large communities made up of individual polyps that secrete a calcium carbonate substance that hardens and builds up to form the reef structure over time. There are different types of corals, such as brain corals and fan corals, that form different types of structures. The coral polyps live symbiotically with algae that provides them with their food. Disease, temperature extremes and pollution can cause corals to expel the algae, leaving only the white calcium carbonate skeleton behind, an event called coral bleaching. Coral bleaching is a worry with global warming heating up the oceans and carbon dioxide causing the oceans to acidify. Coral reefs are important ecosystems because they support larger communities of fish, mollusks, crustaceans and other sea creatures.
The Coral Triangle is the most biodiverse ecosystem in the world and is home to a variety of sea creatures, including sharks, colorful corals and vibrant tropical fish.
Climate change's devastating impact on coral reefs is on display in the new Netflix film "Chasing Coral."
For a reef fish species, sloppy, slimy lip dribbles serve as a vital defense against its coral prey's venomous stings.
Two-thirds of the length of the Great Barrier Reef is suffering from bleaching, a condition likely to cause mass coral die-offs.