
Coral reefs are one of the most complex and colorful tropical ecosystems, rivaling rainforests in their richness of life. Coral reef organisms build massive & intricate physical structures that are home to some of the most fascinating plants and animals in the world. Their extraordinary beauty captivates visitors and their productivity provides a wealth of resources for local communities and the world.
Coral reefs are massive structures made of limestone that is deposited by living things. Although thousands of species inhabit coral reefs, only a fraction produce the limestone that builds the reef.
The most important reef building organisms are corals.
Coral reefs support over twenty-five percent of all known marine species. As one of the most complex ecosystems on the planet, coral reefs are home to over 4,000 different species of fish, 700 species of coral and thousands of other plants and animals. A good way to imagine a coral reef is to think of it as a bustling city or community, with the buildings made of coral, and thousands of inhabitants coming and going, carrying out their business.
In this sense, a coral reef is like a metropolis under the sea.

