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Remote Sensing as a Technique to Document Coral Bleaching Events
Reference
Holden, H. and LeDrew, E.  1998.  Spectral discrimination of healthy and non-healthy corals based on cluster analysis, principal components analysis, and derivative spectroscopy.  Remote Sensing of Environment 65: 217-224.

What was done
According to the authors of this paper, "there exists no objective measure of coral health, so that individual perceptions of the paleness of an individual coral head, or an entire coral reef, are the foundation of coral bleaching reports."  As a result, they indicate that "the scientific basis of these reports is questionable."  Consequently, in an effort to develop an objective methodology for characterizing the presence and extent of coral bleaching, the authors examined the feasibility of using remote sensing techniques for this purpose, collecting in situ spectral reflectance data of various submerged coral reef features at a coral reef in Fiji.

What was learned
Statistical analyses and ground truthing of the remotely sensed data allowed the authors to correctly classify 92% of the healthy corals, 75% of the bleached corals, and 80% of the dead corals.

What it means
Continued remote sensing of coral reefs may provide a clearer, unified, and more objective view of the magnitude and extent of coral bleaching events.


Reviewed 1 July 1999