Coral reef habitat discrimination using multivariate spectral analysis and satellite remote sensing
We tested the hypothesis that in-situ spectral signatures, together with water column attenuation measurements, satellite imagery and Geographical Information System, can effectively differentiate reef substrates. In situ upwelling radiances were collected for coarse descriptive habitat types near Lee Stocking Island, Bahamas between 17 July and 27 July, 1998. Down-looking spectral scans from 300-750 nm were taken 1 m above the substrate and 1 m below the water surface, using a LiCor-1800 underwater spectroradiometer. Principal component analysis of upwelling radiances indicated that wavelengths from 515-580 nm are most useful in distinguishing between substrates. Landsat Thematic Mapper (TM) multi-spectral imagery was geo-registered and an ISODATA unsupervised classification was used to delineate reef features and associated communities. Using this method, we achieved an overall accuracy of 74% for coarse descriptive resolution mapping of seven substrate types (i.e. ocean, deep sand, shallow sand, deep coral, shallow coral, seagrass, and mixed sand and seagrass) within an area of 590 km2 near Lee Stocking Island.
Document Type: Research Article
Affiliations: 1: National Marine Mammal Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, USA;, Email: [email protected] 2: Center for Environmental Science, Huxley College of Environmental Studies, Western Washington University, Bellingham, WA 98225-9181, USA
Publication date: 2003-07-01