New satellite data reveal true decline of world’s mangrove forests

Loss rate for mangrove forests is higher than the loss of inland tropical forests and coral reefs

By Ben Norman, Lifesciencenews@wiley.com
18-Aug-2010 New satellite imagery has given scientists the most comprehensive and exact data on the distribution and decline of mangrove forests from across the world. The research, carried out by scientists from the U.S Geological Survey and NASA, is published in Global Ecology and Biogeography, and reveals forest distribution is 12.3% smaller than earlier estimates. Mangrove forests are among the most productive and biologically important ecosystems of the world, including trees, palms and shrubs which grow at tropical and subtropical tidal zones across the equator. Now scientists can use the world’s most definitive map of the Earth’s mangrove forest to reveal that approximately 53,190 square miles (137, 760 km2) of mangroves exist, substantially less than previous estimates. “Our assessment shows, for the first time, the exact extent and distribution of mangrove forests of the world at 30 meters spatial resolution, the highest resolution ever,” said Dr Chandra Giri from USGS. “This reveals that 75% of the remaining forest is found in just 15 countries, out of which only ~6.9% is protected under the existing protected areas network.” Mangrove forests have adapted to the most severe environmental conditions thriving in regions of high salinity, scorching temperatures and extreme tides across the equator. However, increasingly human activity and frequent severe storms have taken their toll, resulting in a loss rate for mangrove forests higher than the loss of inland tropical forests and coral reefs. “The current estimate of mangrove forests of the world is less than half what it once was, and much of that is in a degraded condition,” said Giri. “It is believed that 35% of mangrove forests were lost from 1980 to 2000 which has had an impact on the coastal communities that use mangrove forests as a protective barrier from natural disasters such as hurricanes and tsunamis.” …

New satellite data reveals true decline of world’s mangrove forests