US Navy
Office of Naval Research: Coral Reefs
Characteristics, location/reef life, humans, and the environment are the topics explored in this competent site. A quick quiz can be found at the end of the text.
NOAA
Noaa: Fisheries: Coral Reefs and the Endangered Species Act [Pdf]
Explore a comprehensive petition regarding the legal preservation of coral reefs and learn how the U.S. Endangered Species Act works to protect the reefs. PDF (requires Adobe Reader).
Other
The Coral Reef Alliance: What You Can Do
Of all coral reefs, 27% have been destroyed or severely damaged. This thorough site provides a wealth of ideas regarding what can be done to preserve coral reefs in the future.
PBS
Pbs Teachers:city in the Sea: Defending Coral Reefs
Research current threats to coral reefs around the world. Write letters to conservation organizations urging support for coral reef protection.