Flat-top Porites Coral (image) University of Hawaii ‑ SOEST Caption This shows flat-top Porites coral on a shallow reef near American Samoa. Coral heads are fully submerged under normal conditions. During El Niño Taimasa, tops of large flat coral on the reef are exposed to air at low tide. Credit Image courtesy of the National Park of American Samoa. Usage Restrictions According to the policies of the National Park of American Samoa Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.