Ours is a blue planet. Oceans, seas and fresh waters cover more than 70% of the Earth's surface. While coral reefs take up only a very small fraction of this, they are home to an astonishing variety of animals and plants, from colourful reef fish to corals and countless other exotic marine creatures. Up to 3000 different species of plants and animals can be found living together on a single coral reef and over 25% of all known species of fish live on or around coral reefs.

Welcome to the world of coral reefs - the bustling cities within our tropical seas!

Topics:

• What makes coral reefs so special? è READ
• What is a coral reef? è READ
• What are corals? è READ
• Corals - animals which don't move around è READ
• A special relationship è READ
• Coral reproduction è READ
• What corals need most è READ
• Distribution è READ
• How old are coral reefs? è READ
• Reefs and change è READ
• Threats to coral reefs è READ
• What can we do to protect coral reefs? è READ