Did you know that coral reefs are underwater cities built from living creatures? It's true! In warm waters near the equator you'll find millions of tiny animals called coral polyps. Some of these animals live together in colonies that make colorful coral reefs. They're even responsible for building the biggest coral reef on earth - the Great Barrier Reef in Australia. Astronauts can even see the Great Barrier Reef and other coral reefs from space!

Coral reefs come in all shapes and colors and are jam-packed with amazing creatures like butterflyfish, blue sea stars, pimply reef crabs, giant clams, and sausage sea cucumbers. Reefs are "buzzing" with sea life! In fact, reefs are home to more than 4000 species of fish, 700 species of coral and thousands of other plants and animals. No wonder coral reefs are called "the rainforests fo the sea."

And you can imagine how important coral reefs are because they provide a home for all of those creatures to live. But they also provide food, medicine and shelter from storms for humans. And don't forget adventure! Have you or your family ever gone diving or snorkeling near coral? Talk about an awesome experience! But sadly, coral reefs are very fragile. Just one touch of a human hand or scrape of a boat anchor is enough to damage them. Coral reefs are also in danger from overfishing, pollution from cities and global warming.