657 New Barrier Islands Identified in Global Satellite Survey

A new global survey of the world’s barrier islands has identified 657 more islands than previously thought, including a 54-island chain that runs along the edges of mangrove forest off the Brazilian coast. Using satellite images, topographical maps and navigational charts, researchers at Duke University and Meredith College identified a total of 2,149 barrier islands, up from the 1,492 identified in 2001. Barrier islands are critical coastal ecosystems consisting of sand and sediment that typically build up parallel to the coast and shift in response to waves, tides, and currents. According to the survey, which is more comprehensive than earlier surveys because of the increasing availability of satellite imagery, barrier islands exist on every continent, except Antarctica, and in all oceans. Barrier islands play a critical role in protecting low-lying coastal areas from erosion and storm damage. About 74 percent of barrier islands are found in the Northern Hemisphere, including 405 along the U.S. coastline.