Bleaching

Corals are ocean-dwelling invertebrates in the same phylum as jellyfish. Corals are tiny and create an exoskeleton that is fixed to something hard, like the remains of previously existing corals. So these organisms build up a geological stratum, a reef, beneath the surface of the sea, often close enough that parts of the reef are exposed at the lowest water level. The coral reef system is the substrate for one of the Earth's major ecological zones. Corals are symbiotic with a single celled dinoflagellate, a kind of algae that combines available nutrients such as ammonia and the…