Extent of Mangrove Forests Less Than Previous Estimates, Survey Shows

The first comprehensive survey of the world’s mangrove forests using satellite imagery reveals that the vital ecosystems are 12 percent smaller than earlier estimates and are swiftly disappearing. Scientists at NASA and the U.S. Geological Survey (USGS), poring over Landsat images with a resolution of 30 meters, estimated that mangrove forests cover 53,190 square miles (137,760 square kilometers) of the planet. The scientists, reporting their findings in the journal Global Ecology and Biogeography, estimated that more than half of the world’s mangrove forests have disappeared, with a third being lost from 1980 to 2000. Mangrove forests, which grow in tropical and sub-tropical tidal zones, are among the most important ecosystems on the planet, providing habitat for marine life and preventing coastal erosion. But human activity, such as shrimp farming, as well as storms and rising seas, have taken a heavy toll on mangrove forests. The survey showed that 42 percent of mangrove forests are located in Asia, 21 percent in Africa, 15 percent in North and Central America, 12 percent in Oceania, and 11 percent in South America. Only 7 percent of remaining mangrove forests are currently protected by parks and reserves.