Mapping submerged corals in Fiji from remote sensing and in situ measurements: applications for integrated coastal management

Current approaches to mapping submerged coral ecosystems by remote sensing techniques are largely confined to the identification of general reef features in shallow tropical waters. Technical difficulties in compensating for the attenuation of radiance through the water column, as well as an incomplete understanding about the specific spectral features of coral and other substrates under normal and stressed conditions, have limited mapping and assessment procedures. This paper reports on recent developments in mapping submerged coral assemblages in Fiji using remotely sensed imagery and in situ field measurements. Preliminary results indicate that the spectral response of corals can be determined up to a depth of 10 m. An accurate and replicable procedure is proposed to quantify the spectral response of various corals and other submerged substrates to determine biodiversity and stress indicators for mapping and assessing coral ecosystems at site-specific and regional locations. Applications of the approach in establishing baseline information, assessing environmental change and managing linked systems within an integrated coastal management framework are highlighted.