Background: Coral Reefs

Background: Coral reefs are often called the "rainforests of the sea" for their high levels of biodiversity despite a scarcity of nutrients. What exactly are corals? Corals are tiny animals that live in colonies and derive nourishment and energy from a symbiotic relationship with zooxanthellae algae known as dinoflagellates. Coral reefs are formed over the course of thousands of years as limestone skeletons constructed by corals accumulate and form a structural base for living corals.

The world's largest coral reef is the Great Barrier Reef, found off the Pacific coast of Australia. The second largest reef lies off the Atlantic coast of Central America, near Belize.

Coral reefs are increasing threatened by climate change, unsustainable fishing practices, the construction business (coral limestone is used for concrete), coastal deforestation (especially of mangroves), soil erosion, and pollution. Even unmanaged tourism and the aquarium fish trade can damage reefs.