National Marine Sanctuary of American Samoa

Research in Fagatele Bay National Marine Sanctuary

Research and Monitoring

The National Marine Sanctuary Program supports research in all of its 14 sites. Research plays a role in management by supplying information needed to make resource protection decisions based on hard scientific data.

Research and Monitoring Fagatele’s Coral Reef
Cycles of Destruction
Research and Monitoring Samoa’s Marine Mammals

Research and Monitoring Fagatele’s Coral Reef

Fagatele Bay's most important research project spans over 20 years. In the late 1970s, millions of Acanthaster planci or crown-of-thorns starfish (alamea), a coral eating animal, ate their way through Tutuila's reefs. More than 90 percent of all the living corals were destroyed. At the time, Fagatele Bay was not a National Marine Sanctuary, but this disaster propelled the decision for the site's designation.

Scientists, headed up by Dr. Charles Birkeland and Dr. Alison Green, used this natural disaster as a baseline for their long-term research to monitor the recovery of a coral reef. Because corals grow slowly, the research team chose a multi-year cycle of data collection. Beginning in 1985, and again in 1988, 1995, 1998, 2001, 2004, and 2007, the team amassed information on coral, fishes, invertebrates and marine plants. This database is unique for Samoa and the study is one of the few long-running surveys of its type in the world. To learn more about research results in Fagatele Bay and American Samoa, see our Publications page.

Checking It Out:

Temperature, Water Quality and Habitat Health

Monitoring is an essential ingredient to any successful resource management program. The resource manager must know the condition of the habitat and the impacts that may be affecting that habitat and its denizens. A long-term monitoring baseline is crucial for decision-making.

The water quality at Fagatele Bay has been consistently good and usually meets the standards that have been developed for the site by EPA—which are stricter than for other coastal waters in Samoa.

Cycles of Destruction:        (return to top)

Starfish, Hurricanes and Heat

American Samoa has been victim to several major natural disasters in the past few decades. Some of these disasters affected both the land and the sea. Some have largely been unnoticed by most people. All of these events have had a major impact on the coral reef habitat that surrounds our islands.

The crown-of-thorns outbreak of the late 1970s has already been mentioned above. In 1991, 1992 and 2005, Samoa was visited by hurricanes. The first and most recent, Hurricanes Ofa and Heta, wreaked some damage to the reef in Fagatele Bay, but most of it was not serious. This was not the case with Hurricane Val, which made a direct pass over Tutuila. Major portions of the reef were obliterated: large swathes appeared to have been scoured. In response to this disaster, NOAA sent an assessment team to survey the reef.

The summer of 1993-94 gave the Sanctuary a different natural disaster, one largely unknown to most people. A pool of unusually hot water surrounded Samoa for several months and caused most corals and many other invertebrates to "bleach" or to lose the pigment-carrying dynoflagellates (zooxanthellae) that normally coexist with the animal. A temperature change of just a few degrees will be enough to stress the corals so that they bleach. Without the zooxanthellae, the reefs appeared brilliantly white. Many corals were injured and died. Subsequent warm water periods in later years have caused smaller bleaching events, and bleaching has virtually become an annual event as average water temperatures increase with global warming.

This cycle of disaster and recovery may seem a cruel joke to us, but to the tropical environment it is merely the status quo. The coral habitat is adapted to change. Recovery is measured in decades, but as long as conditions return to "normal" the reef and its inhabitants will return.

Human's use of the land and sea can impact the recovery process, delaying or preventing it. Sediment resulting from poor land practices can smother and kill a reef and will prevent new corals from forming. Water pollution will also destroy habitats. The coral reef is a precious resource and it is our responsibility to protect it for future generations to enjoy. Fagatele Bay National Marine Sanctuary protects its coral reef resources for everyone, and works collaboratively with local, regional and federal agencies as a member of the American Samoa Coral Reef Advisory Group.

Research and Monitoring Marine Mammals  (Return to top)

Humpback Whales, our winter visitors

whaleSince 2003, an annual survey of Tutuila’s marine mammals focusing on the humpback whales that visit each winter, has been conducted by the Hawaiian Islands Humpback Whale National Marine Sanctuary’s former Research Coordinator, David Mattila. In cooperation with other local agencies, including the Department of Marine and Wildlife Resources and the National Park of American Samoa, researchers have gathered photos and skin samples of dozens of humpback whales, expanding our knowledge about this species. The photos help to identify individual animals: humpback flukes, or tails, are distinctive for every individual like human fingerprints. Skin samples provide additional information including the sex, the reproductive status of a female, and what types of fat-soluble pollutants are in their bodies.

Humpback whales are known for a behavior found in few other animals—they sing. Male humpbacks sing long, complex “songs” that are haunting and distinctive. No one knows why humpbacks sing, though theories abound. Recordings of a song—every year all whales sing that year’s ‘hit tune’, which changes a little over the season—supply more information for the researchers. For more information, visit the endangered species page.

Scientists are discovering that humpbacks are more abundant in Samoa than formerly believed. These 45 ft. mammals travel to American Samoa waters each winter from June through October. They come here to calve and nurse their young in the sheltered bays of the islands until the calves are large enough to undertake the long trek back to the Antarctic feeding grounds. Males vie for the attention of females, and although mating has never been observed, the females are pregnant by the time they reach Antarctica. Download this pdf (628 KB) for more information about humpback whale research in American Samoa.

Other Marine Mammals             (Return to Top)

Other species of marine mammals live year round in Samoan waters, some preferring coastal waters, and other the deeper open ocean. Bottlenose, spinner and rough-toothed dolphins and false killer whales have been documented in our surveys.

A small pod of rough toothed dolphins seen near Tutuila.False killer whale adult and calf.
A small pod of rough toothed dolphins seen near Tutuila. False killer whale adult and calf.
Curious bottle-nosed dolphinsA spinner dolphin leaps in the surf.
Curious bottle-nosed dolphins. A spinner dolphin leaps in the surf.

Want to know more? Check out these links:

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Revised July 19, 2017 by National Marine Sanctuary of American Samoa | Contact Us
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