Ecosystems: Coral Reefs

kelp forest
Pocillopora (above) and Acropora species are the dominant genera on reefs in Fagatele Bay National Marine Sanctuary.
Fagatele Bay National Marine Sanctuary

Location: 12 km southwest of Pago Pago Harbor on the southern most point of Tutuila, American Samoa (14o23' S, 170o46' W)

Reef Structure and Physical Features: Fagatele Bay (pronounced fung'-a-tell-ee) is formed by a collapsed volcanic crater and is surrounded by steep cliffs and volcanic rocks. The total area of Fagatele Bay is approximately one quarter of a square mile. The beaches are primarily calcareous sand with a small amount of volcanic sand. The sand deposits extend about 5 to 10 m offshore until they merge with the reef platforms, composed primarily of consolidated limestone and encrusting algae. The platforms fringe the shore of the bay and are 60 m or less wide, 0.6 m deep, with bottom relief of about 0.3 m. The reef platform extends about 60 m offshore to the reef front.

Coral Species and Cover: Approximately 172 coral species have been recorded for the area. The most conspicuous include: Pocillopora verrucosa, Favia species, Galaxea species, Goniastrea species, Acropora humilis, Porites lutea, and the soft coral Palythoa species.

Along the eastern edge of Fagatele Bay, 10 percent of the reef flat is covered by coral, while another 5 percent contains dead coral heads. Coral cover on the reef terrace was 30-100 percent in the late 1970s, prior to the population explosion of a coral predator called the crown-of-thorns seastar, Acanthaster planci.

Other Fauna and Flora: Humpback whales are found in the bay and adjacent waters from July to October, their breeding and calving season. Sperm whales are occasionally sighted offshore. Other cetaceans such as Pacific bottlenose and spinner dolphins also use the bay and adjacent waters. Hawksbill and green sea turtles are frequently found and leatherbacks, olive ridleys, and loggerheads have been recorded. Thirty-nine marine plant species and hundreds of fish species have been recorded. Anemones, lobsters, limpets, clams, octopuses, and sea urchins may also be found in the bay.

leaving site indicates a link leaves the site. Please view our Link Disclaimer for more information.
Revised June 21, 2013 by Sanctuaries Web Team | Contact Us | Web Site Owner: National Ocean Service
National Ocean Service | National Oceanic and Atmospheric Administration | Privacy Policy | For Employees | User Survey
http://sanctuaries.noaa.gov/about/ecosystems/coral_fb.html