Coral Reefs

I need to write a research paper on coral reefs. My professor gave me some pointers including but not limited to: What groups they classify in and Phylum, how they get energy, how they produce skeleton, habitat requirements, how they feed, and how many different species for the introduction. I’m assuming that the body will be about different kinds of corals that exist, and fun facts about them. in conclusion I’d like to talk about how they are in trouble and what we can do to help.