How valuable are coral reefs?

Have a look at the following articles which explore the importance of coral reefs as one of our planets most biodiverse environments.

WWF - The importance of coral reefs
This article gives a great general overview about the different values of coral reefs with some excellent examples. Year 11 - you may want to add to your notes a little using this article.

Coral Reefs - an underwater pharmacy
This article focuses specifically on the role of coral reefs as a future source of medicines for humans.