What gives coral its beautiful color?
Coral is made up of many tiny polyps that are attached to each other by a calcium carbonate skeleton that they secrete. Alone, all coral would be white, the color of the calcium carbonate skeleton. However, each polyp contains several unicellular yellow-brown dinoflagellate algae called zooxanthellae. These zooxanthellae have a symbiotic relationship with the coral. The coral provides protection and access to light for the zooxanthellae and the zooxanthellae provide nutrients for the coral via photosynthesis. Since the zooxanthellae must accomplish photosynthesis, they are filled with various pigments to absorb sunlight. It is these pigments that give coral its color. What is coral bleaching? Coral bleaching occurs when the corals lose their symbiotic zooxanthellae or dinoflagellate algae that live in the coral polyps, which is what give the coral its beautiful color. The calcium carbonate skeletons of the coral colony are exposed with the loss of their symbiotic counterpart, causing t
