A Benthic Terrain Classification Scheme for American Samoa

Abstract

Coral reef ecosystems, the most varied on earth, continually face destruction from anthropogenic and natural threats. The U.S. Coral Reef Task Force seeks to characterize and map priority coral reef ecosystems in the U.S./Trust Territories by 2009. Building upon NOAA Biogeography shallow-water classifications based on Ikonos imagery, presented here are new methods, based on acoustic data, for classifying benthic terrain below 30 m, around Tutuila, American Samoa. The result is a new classification scheme for American Samoa that extends and improves the NOAA Biogeography scheme, which, although developed for Pacific island nations and territories, is only applicable to a maximum depth of 30 m, due to the limitations of satellite imagery. The scheme may be suitable for developing habitat maps pinpointing high biodiversity around coral reefs throughout the western Pacific.

Keywords:

• terrain analysis
• bathymetry
• benthic habitat
• marine GIS
• American Samoa
• corals

Acknowledgments

This work has been done under the auspices of the European Space Agency in the frame of the Postdoctoral Research Fellowship Programme. Pierre Femenias and Jerome Benveniste, from ESRIN-ESA, supplied the SGDR records used in this work under a Category-1 Project lead by Graham Quartly (National Oceanography Centre, Southampton). The authors want to thanks María Pilar Milagro-Pérez, from ESRIN-ESA, for all the technical documents she provided and the clarifications about the format of the RA-2 SGDR products. We would also like to thank the EOHelp Team at ESRIN-ESA for the help in the distribution of the SGDR data.

This research was supported by NOAA Coastal Services Center (CSC) Special Projects for the Pacific Islands Initiative, Grant #NA03NOS4730033 to D. Wright and additional NOAA support to D. Naar. We acknowledge the logistical and financial support from Marine Sanctuary Director, Nancy Daschbach, as well as the warm hospitality provided by the local villages adjacent to Fagatele Bay and Vatia Bay. Others instrumental in this project were Will White (formerly of Department of Marine and Wildlife Resources), John Rooney (CRED), Peter Craig (National Park of American Samoa (NPAS)), Allison Graves (formerly of NPAS), Curt Whitmire (NOAA Northwest Fisheries Science Center), Anita Grunder (Oregon State University), Joshua Murphy and Lori Cary-Kothera (CSC), Jeff Jenness (Jenness Enterprises), Pat Iampietro (California State University, Monterey Bay), and Will Smith (Hawaii Institute of Marine Biology). The comments of two anonymous reviewers significantly improved the manuscript.