Orange cup coral clusters on a pier piling on Bonaire Island in the West Indies. About 80 percent of all life on Earth is found in the oceans, which cover 71 percent of the planet's surface.
A large rust-colored gorgonian sea fan perches against a reef in Micronesia. Small, individual coral polyps fuse together over time to create these impressive fan-shaped colonies, which can grow several feet high.
Shelves of coral surround the Pacific island of Palau. Corals, small organisms related to anemones, secrete calcium carbonate which hardens into an exoskeleton and over time forms reefs.
A school of striped grunt fish glides over a coral reef in the British Virgin Islands. Coral reefs are rocklike structures built by layers of coral organisms, called polyps. They support about 25 percent of all marine life.
A saddled butterfly fish feeds on gorgonian coral off the coast of Palau, an island republic located about 500 miles (800 kilometers) east of the Philippines. Coral reefs are found only in warm waters between 30 degrees north and 30 degrees south latitudes.