Benthic Habitat Data

Bathymetry

Zipped data files contain 1) grid data file (GMT or ASCII), 2) high-res JPG of image, and 3) explanatory metadata text file (identical to linked file listed below).

5m grid data

NetCDF/GMT:
Metadata text • Zipped data
Arc ASCII:
Metadata text • Zipped data

Merged Multibeam Bathymetry, IKONOS Derived Depths

View Metadata:
- Coverage Map Metadata text
- 5m Metadata text
Zipped Data:Arc ASCII

Optical Validation

View: Metadata
2002 | 2004 | 2008 | Map
View: Metadata for Mobile Fauna
2002 | 2004 | 2008 | Map
Download: Shapefiles, JPG & metadata
2002 | 2004 | 2008 | All
View: Optical Images

Benthic Habitat Map System

ArcGIS & ArcReader projects which integrate acoustic & optical data with reference to available terrestrial data.

Geomorphology

Zipped data files contain 1) Arc ASCII file, 2) layer (.lyr) file for symbology, 3) high-res JPG of image, and 4) explanatory metadata text file (identical to linked file listed below).

5m grid data

Substrate GeoTIFFs: Hard bottom vs. Sand bottom
- Simrad em3002d data:
  Metadata text • Zipped data
- Reson 8101 data :
  Metadata text • Zipped data

Slope Arc ASCII:
Metadata text • Zipped data
Rugosity Arc ASCII:
Metadata text • Zipped data
BPI Structures Arc ASCII:
Metadata text • Zipped data
BPI Zones Arc ASCII:
Metadata text • Zipped data

American Samoa: Tutuila

[ Bathymetry | Backscatter | Optical Validation | Geomorphology]

Optical Validation

The collection and analysis of photographic data to ground truth and interpret multibeam data layers with the goal of characterizing seafloor habitats.

Coral Cover Map

Click thumbnail map to view a high-resolution JPG.

Descriptions of optical data products.

Download: Accessory Files

The map above shows percent cover values of scleractinian coral derived from classified photos and videos collected at Tutuila in 2002 and 2004. Each point represents an analyzed video frame or photo. Note that the percent classes are unevenly sized to better display this relatively low-abundance bottom type.

The optical data are classified by substrate type, type of live growth on bottom, geomorphic zone, and the size and abundance of holes in the substrate. Although what we show here is the percentage of coral, the shapefiles contain data on all those categories, enabling users to map the occurrence of any combination of characteristics that are included in the classification scheme. (See sidebar for shapefiles.)

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Mobile Fauna Map

Click thumbnail map to view a high-resolution JPG.

Descriptions of optical data products.

Download: Accessory Files

The map above shows total fish biomass from towed camera sled (TOAD) videos collected at Tutuila Island in 2002, 2004, and 2008. Optical data from 2002 collected as still photographs were not suitable for mobile fauna classification and therefore are not included. Each point represents a thirty second video interval centered on a location derived from points classified in the optical validation maps. Note that size classes are unevenly distributed to minimize in-class variability.

The mobile fauna data contain biomass estimates as well as the numbers of fish which make up that total biomass (tonnes/hectare). Although the mobile fauna maps present biomass, fish numbers can be found in the underlying shapefiles (see layer file description for instructions). This enables users to obtain a more detailed understanding of the distribution of fish assemblages. Benthic classifications associated with these data can be downloaded with the other Optical Validation data.