Mapping of shallow coral reefs by colour aerial photography

True-colour aerial photography and underwater photography together with digital image processing techniques were applied to identify and describe the spatial array of the main bottom elements of two common reef environments: a stony coral assemblage and a seagrass bed. The procedure adopted consisted of generating an unsupervised classification, coupled with field verification, and then a supervised classification. This method permitted the generation of stony corals and seagrass distribution maps; the spatial resolution of these maps is of the order of 40 cm. Limitations and potentiality of the method to high-resolution mapping of shallow coral reef environments are discussed.