Research Expedition Returns to American Samoa and the Pacific Remote Islands to Assess Reef Conditions and Recovery from Mass Coral Bleaching

Diver conducts survey of bleached corals at Tutuila Island in American Samoa.

Diver conducts survey of bleached corals at Tutuila Island in American Samoa.

On March 19, scientists from the NOAA Pacific Islands Fisheries Science Center embark on a 105-day Pacific Reef Assessment and Monitoring Program (Pacific RAMP) mission aboard the NOAA Ship Hiʻialakai to assess the status and potential changes in the coral reef ecosystems of American Samoa (including the National Marine Sanctuary of American Samoa and the National Park of American Samoa), the Pacific Remote Islands Marine National Monument, and the Rose Atoll Marine National Monument. This expedition is part of the National Coral Reef Monitoring Program of NOAA's Coral Reef Conservation Program, with the overall goal of providing a consistent, comparable flow of long-term assessment and monitoring information to document and report the status and trends of the nation's coral reef ecosystems and the processes that sustain them.


Pink whipray (Himantura fai) on coral reefs at Swains Island in American Samoa.

The 2018 Pacific RAMP expedition marks the eighth research voyage to American Samoa and tenth voyage to the Pacific Remote Islands Marine National Monument by Pacific Islands Fisheries Science Center staff and partner agencies. Partners participating in this mission include scientists from the American Samoa Department of Marine and Wildlife Resources, the NOAA Office of National Marine Sanctuaries in American Samoa, Hawaiʻi Institute of Marine Biology, San Diego State University, Scripps Institution of Oceanography, the U.S. Fish and Wildlife Service, and Woods Hole Oceanographic Institution. Scientific staff from the U.S. Fish and Wildlife Service include wildlife biologists continuing their ongoing efforts to monitor terrestrial biological resources of the Monuments and National Wildlife Refuges within these areas.


Baby octopus found on an Autonomous Reef Monitoring Structure in American Samoa.

Under the direction of Chief Scientists Jacob Asher, Brett Schumacher, and Bernardo Vargas-Ángel, teams of scuba divers will deploy from the NOAA Ship Hi‘ialakai to conduct rapid ecological assessments of reef fishes, corals, other invertebrates, and algae, as well as install and retrieve autonomous reef monitoring structures to assess the taxonomic diversity of “cryptic” coral reef species (e.g., small crabs, shrimp, snails, etc.). Scientists will collect data on water temperature, salinity, carbonate chemistry, and other physical and chemical characteristics of the coral reef environment with an assortment of oceanographic monitoring instruments. Researchers will also assess impacts of ocean acidification on the balance between production (accretion and calcification) and removal (bioerosion and dissolution) of the coral reefs.

The expedition consists of several segments, or legs. During the first leg of the expedition, scientific operations will be conducted at Johnston Atoll, Howland and Baker Islands of the Pacific Remote Islands Marine National Monument, and at Swains Island and Tutuila Island in American Samoa. The Pacific Remote Islands Marine National Monument was created by Presidential Proclamation in 2009 and recently expanded in 2014. It is currently under review for potential revision, along with the Rose Atoll Marine National Monument. These monuments, located far from any major human population centers, contain some of the most pristine coral reefs in the world, and thus offer unique opportunities for studying and understanding how coral reef ecosystems function in the absence of direct human impacts.

In the second and third legs of the expedition, scientists will conduct biological and oceanographic surveys throughout remaining areas of American Samoa, including Tutuila, Rose Atoll, Ofu and Olosega Islands, and Taʻu Island. Work by scientists aboard the Hiʻialakai complements coral reef research efforts of local management agencies, who utilize the ship to provide the capability to survey areas of islands that are relatively inaccessible otherwise.

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Arc-eye hawkfish (Paracirrhites arcatus) in dead cauliflower coral (Pocillopora species) at Jarvis Island after coral bleaching.

On the ship's return voyage to Honolulu, during the fourth leg of the expedition, surveys will be conducted at three other islands of the Pacific Remote Islands Marine National Monument: Jarvis Island, Palmyra Atoll, and Kingman Reef. In 2015–2016, Jarvis Island experienced a prolonged period of abnormally warm sea surface temperatures that caused severe coral bleaching, where the symbiotic algal partners that normally live within coral tissue are lost. The ESD and partners surveyed Jarvis Island in 2016 and 2017 and found that coral populations had been severely impacted by this event, with 98% coral mortality observed.

These studies will provide scientists and managers with valuable information about the ways coral reef ecosystems are impacted and (hopefully) recover in remote locations. Studies in remote locations are especially useful scientifically because reefs in many of these locations are free from locally generated stressors by humans such as the effects of land-based sources of pollution and fishing pressure.


Diver conducts survey to assess reef condition after coral bleaching at Jarvis Island. One of the few remaining Acropora corals in the foreground and red turf algae growing over damaged corals.

Data collected by the scientific staff on this expedition will add to a comprehensive set of ecological data from islands in the Pacific Ocean. With each expedition, the data set grows more robust and valuable for evaluating changes through time. By integrating data on the abundance and spatial distribution of reef fishes and benthic organisms and the oceanographic environment in which they live, scientists will be able to critically evaluate potential changes in the condition and integrity of coral reef ecosystems. Most importantly, this perspective enables federal and local resource managers to make informed decisions aimed at sustainable management of the coral reefs throughout American Samoa and remote islands in the Pacific Ocean.