Visual Surveys of Reef Fishes and Coral Reefs Underway in American Samoa

April 13, 2016 (updated 4/28/2016)

Between 13 April and 31 May 2016, the NOAA Ship Oscar Elton Sette will be the platform for a research project aimed at gathering data to improve assessments of reef fish populations in American Samoa and to assess the aftermath of the 2016 coral bleaching events at Rose Atoll and Jarvis Island. This effort is led by Project Leader, Kevin Lino, and Lead Scientist, Adel Heenan and Chief Scientist Bernardo Vargas-Ángel, of the NOAA PIFSC Coral Reef Ecosystems Program (CREP); however it is a multi-agency effort, involving participants from the American Samoa Department of Marine and Wildlife Resources, the igelow Laboratory for Ocean Sciences, and Woods Hole Oceanographic Institute.

Divers conclude the visual survey by photographing the reef.
Divers conclude the visual survey by photographing the reef.

Prior to embarking, divers undergo rigorous training, including learning hundreds of fish species and passing numerous fish ID tests, classroom lectures on methods, and in water training dives. In order to prepare partners for the project, CREP Marine Ecosystem Research Specialist Paula Ayotte will spend a week in American Samoa training partner researchers from the American Samoa Department of Marine and Wildlife Resources, the American Samoa Coral Reef Advisory Group, as well as the Bigelow Marine Lab.

During the expedition, scientists expect to conduct some 400 underwater visual surveys for reef fishes and habitat, with sites widely spread across coral reef areas around the islands of Tutuila, Taʻu, and Ofu & Olosega, and Rose Atoll. The survey methods and sampling design used will be consistent with those implemented for NOAA's existing National Coral Reef Monitoring Plan (NCRMP) (5.3 MB PDF) in Samoa and Pacific-wide, and therefore data can be readily combined and compared. These survey efforts are primarily designed to improve the ability of PIFSC and partners to accurately document the status and trends of coral reef fishes around American Samoa. Nonetheless, because the overall dataset is highly consistent and widely representative of reef areas across the region, it is suitable for multiple purposes and is being increasingly used for large-scale scientific research by NOAA and external researchers.

A side project conducted during the cruise will be to compare fish counts gathered by divers on closed-circuit rebreather (CCR) with those by divers using standard SCUBA equipment. Divers on CCR do not produce bubbles and therefore represent a much quieter and less intrusive presence in the marine environment. As such, it is possible that use of CCR may enable divers to obtain better information on species that are wary of divers.

In addition to the work in American Samoa, the expedition will spend 10 days at Jarvis Island in the US Line Islands. Jarvis is an unpopulated and remote island that typically harbors among the highest fish biomass (7.9 MB PDF) recorded at any island visited as part of CREP's Pacific coral reef monitoring program. Abnormally high and prolonged sea surface temperatures at Jarvis Island over recent months have potentially led to severe coral bleaching, in addition to other substantial changes in the status of coral reef resources. NOAA staff and partners will spend their time at Jarvis quantifying and documenting the extent of the bleaching impacts.

As with all data gathered by the NOAA, any information collected during the cruise is available on request. All coral reef survey data gathered by CREP and partners is routinely reported in post-cruise monitoring briefs and annual data reports.