Summit-to-Sea mapping and change detection using satellite imagery: tools for conservation and management of coral reefs

(ETM+) Imagery. Continuous land/sea terrain was mapped by merging Digital Elevation Models (DEM) with satellite-derived bathymetry. Benthic habitat characterizations were created by unsupervised classifications of Landsat imagery clustered using field data, and produced maps with an estimated overall accuracy of>75 % (Tau coefficient>0.65). These were merged with Geocover-LC (land use/land cover) data to create continuous land/ sea cover maps. Image pairs from different dates were analyzed using Principle Components Analysis (PCA) in order to detect areas of change in the marine environment over two different time intervals: 2000 to 2001, and 1991 to 2003. This activity demonstrates the capabilities of Landsat imagery to produce continuous summit-to-sea maps, as well as detect certain changes in the shallow-water marine environment, providing a valuable tool for efficient coastal zone monitoring and effective management and conservation. Key words: remote sensing, benthic habitats, change analysis, Landsat, coral reefs, mapping. While concern is growing about the state of the earth’s shallow water (<30 m) coral reefs, projects to quantify the extent or condition of these ecosystems at global or regional scales are limited by cost, accessibility, and magni