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: Restoration of Coral Ecosystems
The Coral Reef Restoration Center provides reasons why coral reefs are being destroyed, current or recent restoration activities, and future restoration efforts.
NOAA
Noaa: Coral Reef Watch: Satellite Coral Bleaching Monitoring
This site provides a concise explanation of the bleaching process, its effect on corals, and the causes of bleaching.