This image, taken on 10 May 2001, shows one of the islands of New Caledonia, an archipelago 1200 kilometers (750 miles) east of Australia. New Caledonia contains the world’s third-largest coral reef structure, and its coral reefs support an unusually large diversity of species, including many predators, big fish, turtles, and the world’s third-largest dugong population. (Dugongs are large marine mammals.) In this natural-color image, the islands appear in shades of green and brown — mixtures of vegetation and bare ground. The surrounding waters range from pale aquamarine to deep blue, and the color differences reflect varying water depths. Over coral reef ridges and sand bars, the water is shallowest and palest in color.