Benthic Habitat Mapping and Characterization
Study Areas and Data Downloads
The NOAA Coral Reef Conservation Program (CRCP) addresses the priorities laid out in both the National Action Plan to Conserve Coral Reefs (2000) and the National Coral Reef Action Strategy (2002) by funding coral reef benthic habitat mapping and characterization throughout U.S. waters.
The first of several goals defined within the strategy is to create comprehensive maps of all U.S. coral reef habitats. Specifically, the report calls for the production of comprehensive digital maps of all shallow (< 30 meters) coral reefs and the characterization of priority deep water (> 30 meter) reef systems in the U.S. and Trust Territories by 2009. Benthic habitat mapping and characterization is a fundamental component of ecosystem-based coral reef management because it integrates a variety of information to define the extent, nature and health of these ecosystems. Without accurate maps resource managers cannot make informed decisions; although our products are publicly available, these managers are the primary users of our data.
NOAA’s Biogeography Program leads the effort to comprehensively map the distribution of shallow coral reefs and other benthic habitats. In the Pacific Islands region this has been accomplished primarily through the development of maps based on IKONOS satellite imagery. When the Pacific Islands Fisheries Science Center established the Coral Reef Ecosystems Division (CRED) in 2001, the Center initiated a program to extend habitat mapping in the U.S. Pacific Islands into deeper water that cannot be readily mapped using satellite and aerial techniques. Since that time NOAA Fisheries has led the effort to map these deeper reefs using ship-based acoustic mapping systems, coupled with video and still-camera observations. These sonar and optical data are combined with the IKONOS-based data products and oceanographic information to provide integrated products that describe the benthic habitats of the Pacific Islands.
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| CRED Study Areas |
CRED began systematic mapping in 2001 using a single-beam based bottom classification system and a towed optical assessment device (TOAD); these instruments have been used on numerous cruises aboard the NOAA Ships Townsend Cromwell and Oscar Elton Sette. Plans were also initiated to develop a mapping capability based on high-resolution multibeam sonar that would be used from 20 meters into waters as deep as 250 meters.The result was the R/V AHI (Acoustic Habitat Investigator), a 25-ft survey launch, which was commissioned in 2003. During AHI’s first year of operation, over 750 km2 of seafloor in water depths between 10-350m were mapped in the NWHI, CNMI, Guam and American Samoa In 2002, our scientists participated in a mapping cruise in the NWHI aboard the University of Hawaii’s R/V Kilo Moana that collected over 38,000 km2 of multibeam data in 20-5000m water depths. In 2004 the TOAD was replaced with two more capable TARAS underwater camera systems. More details about our tools and methodology are available.
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| R/V AHI conducting surveys in Saipan. Photo by Bruce Appelgate |
We work closely with a variety of partners both inside NOAA and with other federal, state and local agencies in the Pacific Islands Region. The strongest partnership is with the University of Hawaii’s Hawaii Mapping Research Group (HMRG). HMRG has more than 20 years of experience conducting sonar field operations and generating seafloor imagery products for scientific, government, and commercial users and has developed a suite of software tools and data processing techniques to process and analyze sonar data, and to create and disseminate useful data products. Rather than duplicate these efforts, CRED worked with HMRG to expand upon their capabilities by incorporation of techniques for development of habitat maps. Data collected and processed jointly by CRED and HMRG can be accessed via the Pacific Islands Benthic Habitat Mapping Center.
In order to develop benthic habitat maps, an organizational structure must be chosen that reflects the information that can be extracted from the underlying data. The model we have chosen is patterned after classification schemes NOAA developed using IKONOS and hyperspectral imagery, and reflects the type of information that can be extracted from the bathymetry, acoustic imagery, and optical data sets that we routinely collect.
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| IKONOS imagery is shown draped over a 10-m USGS DEM and over multibeam bathymetric data collected around Olosega Island, American Samoa, in March 2004. Credit:NOAA PIFSC |
