The three main types of coral reefs are fringing, barrier, and atoll.
The most common type of reef is the fringing reef. This type of reef grows seaward directly from the shore. They form borders along the shoreline and surrounding islands.
When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center.
Barrier reefs are similar to fringing reefs in that they also border a shoreline; however, instead of growing directly out from the shore, they are separated from land by an expanse of water. This creates a lagoon of open, often deep water between the reef and the shore.
Coral reefs are important because they bring in billions of dollars to our economy through tourism, protect coastal homes from storms, support promising medical treatments, and provide a home for millions of aquatic species.
NOAA’s Coral Reef Conservation Program works to protect coral reefs through research, education, and preservation programs. Many reefs, such as the Virgin Islands Coral Reef National Monument, are housed in NOAA’s system of marine protected areas.
Get Social
More Information
- NOAA Coral Reef Conservation Program
- U.S. Coral Reef Task Force
- NOAA Coral Reef Information System
- Corals Tutorial
- Five Things You Should Know About Coral Reefs
- Value of Coral Reefs (audio podcast)
Last updated: 01/18/24
Author: NOAA
How to cite this article
