Live, healthy coral has algae in its outer tissue layer, living in a symbiotic relationship. When coral is under stress, from water chemistry, temperature changes or other factors, it expels the algae to protect itself. This process is called coral bleaching. While coral reefs occupy only 1% of the ocean, they hold approximately 25% of the species, making them the most diverse of all marine habitats.
SSC Aquarist Rob Royer features the Center’s tropical Coral Reefs tank in this video. Similarly, coral reefs in the Gulf of Maine are equally important habitats, which are also subject to coral bleaching.