Fagatele Bay on the Samoan island of Tutuila is the remnant of a volcanic crater that was breached and flooded by the ocean in the last 11,000 years. (photo: Kip Evans)

Steep ridges, primarily composed of basaltic rocks formed by lava flows, make Fagatele Bay relatively inaccessible by land. Manautuloa Ridge, shown in the distance, bounds the eastern side of the bay and is over 200 feet high.(photo: Kip Evans)

The coral formations in Fagatele Bay are found very close to shore. The beach (upper left) is only about 20 feet wide and 200 long at high tide, and is composed mainly of calcareous sand. (photo: Kip Evans)

The steep cliffs surrounding Fagatele Bay have helped the area remain undisturbed and free of introduced coastal and littoral vegetation. (photo: Kip Evans)

The ubiquitous aspect of Fagatele Bay is its extensive coral reef ecosystem. To date, over 600 species of corals, macroinvertebrates, fish, and microalgae have been recorded in the bay's waters. (photo: Kip Evans)

These Acropora hyancinthus tabletop corals were once one of the dominant species in Fagatele Bay until Crown of Thorns starfish attacked them in the 1970s. (photo: Kip Evans)

Generally, there are about twice as many coral species in Pacific Ocean reefs as in Atlantic Ocean reefs. The maximum number of species are found in reefs of the southwest Pacific (photo: Kip Evans)

Climatic change and rise and fall of sea level are significant influences on coral reefs. Over geologic time, the southwest Pacific has enjoyed the most continuous occupation of coral reefs worldwide. (photo: Kip Evans)

Coral reefs are generally found in tropical and subtropical waters between 25 degrees north and 25 degrees south latitude. They are usually also limited to areas of open marine salinity, and are rarely found in estuaries. (photo: Kip Evans)

Bleaching occurs when coral become stressed by heat, cold, chemicals, or other factors. When corals are stressed they expel the symbiotic zooxanthellae (algae) that live inside their tissues and give the coral its color when alive. (photo: Kip Evans)

The shallow depth of most coral reefs and atolls make them highly susceptible to storm damage. Much of the structure of this reef has been obliterated by a storm. (photo: Nancy Daschbach)

This is coral rubble, the result of storm damage. These dead coral skeletons will be "glued" together by coralline algae to form a solid substrate for future colonization. (photo: Kip Evans)