Coral reefs are made up of colonies of hundreds to thousands of tiny individual corals, called polyps. These marine invertebrate animals have hard exoskeletons made of calcium carbonate, and are ...

individual coral reefs, and every one of them is in a different condition. Narrator: It's also the world's largest living structure as well as a home to thousands of plant and animal species.

Reef sounds are beneficial to some marine animals, which use them to locate reefs – a source of food and shelter. For researchers, recent studies suggest that sound recordings could be an effective ...