Science Minute Script:

Download Quicktime to listen to the audio clip.

How is a Coral Reef Formed?

This Science Minute was researched and written by Sam C., of Ithaca, NY.

Corals are among the most amazing animals on the planet.

Corals are important because they make up reefs, which provide a home for many other animals. You can think of a coral reef like a busy city: the corals are the buildings, and the other animals that live in them are the people.

Reefs are formed when colonies of corals grow on the ocean floor. Over the years, the colony grows as new corals join and existing corals multiply. Over thousands of years, hard corals die and leave skeletons, and new corals grow on top of the skeletons. There are over 500 kinds of coral that form reefs.

Coral reefs are usually found in warm, clear, shallow water. They feed and shelter thousands of different species of plants and animals, including over 4,000 kinds of fish. Overall, coral reefs are home to more than 25 percent of all marine species.