We take weekly readings of sediments and currents. The wider picture A short boat ride across the turquoise waters from St Anne is Mah, the Seychelles' main island. High on a cliff above the capital, Victoria, are two giant white spheres which glow orange in the setting tropical sun. Previously used for a USA satellite cleansing system, the site may soon house a ground receiving station for SeaWiFS satellite data. The images it generates would enable the team to identify areas rich in plankton, the microscopic plants and animals that lie at the bottom of the food chain.
Plankton float freely and can yield information on fish stocks and ocean currents.
Having the satellite images at their fingertips would help the Shoals scientists gather information on vast areas very quickly. Visiting scientists from Imperial College, London, are also pioneering a type of remote sensing where the data is gathered using side-scan sonar. A tool that looks like a big fish is tied to the back of a boat, and the scientists traverse an area of interest. As they do so, the scanner pulses out regular sonar signals. Like the satellite imagery, it may help scientists differentiate between habitat types or live and dead reef.