Scientists found that mangrove forests began expanding worldwide around 2010 after decades of loss, according to research published in Science and described by NASA Earth Observatory. Growth in Asia, Australia, and South America led the rebound.
The shift matters for coasts and for carbon stored in these forests, NASA Earth Observatory reported. Mangrove ecosystems can hold as much as four times the carbon of taller tropical forests farther inland. The trees average about 13 meters (43 feet), help shield communities from erosion and storm-driven water, and their raised roots shelter fish, shrimp, crabs, and other marine animals.
The researchers examined Landsat satellite images gathered from 1984 through 2023, looking for changes in canopy reach and thickness. They tallied losses of nearly 3,000 square kilometers (1,200 square miles) from 1984 to 2010, then what they described as an unexpected increase of nearly 2,000 square kilometers (770 square miles) after 2010. Many of today’s forests also had thicker, more closed canopies than in 2010, especially in South America, a sign of healthier stands, NASA Earth Observatory reported.
Scientists have mapped mangroves from space since the 1970s, after the first Landsat satellite launched. For decades those maps mostly showed decline. Zhen Zhang, an environmental scientist at Tulane University, said the new work produced the first worldwide mangrove maps spanning so many years.
“About two-thirds of the expansion was due to mangroves colonizing new areas and the other third due to restoration and regrowth in degraded areas,” Zhang said.
A notable reversal came in Southeast Asia, especially Burma, also called Myanmar. The country lost mangroves quickly in the 1980s and 1990s as farming, fish and shrimp ponds, and firewood cutting spread along the coast. The authors tied the change after about 2010 to wider awareness and replanting after the 2004 Indian Ocean tsunami, tougher forest laws, and heavy sediment that opened new mudflats, NASA Earth Observatory reported.
Paired Landsat views of Palaw Township in Burma’s Myeik District, from Feb. 14, 2010, and Feb. 2, 2026, show trees filling former rice fields south of Kyauktaung and spreading onto new ground. Residents of nearby Pyin Bukyi Island have tried local conservation and planting projects. From the 1980s to 2010, Burma’s mangrove cover fell by 28.6 percent; afterward it rose about 10 percent. Clearing of forest is still common there, the account said.
Sediment has also built mudflats that mangroves occupied near the mouth of the Amazon River and in northern Australia, with steady gains in each region since the 1990s. At the northern and southern limits of the trees’ range, including the southeastern United States, warmer conditions and fewer freezes have let mangroves enter places once too cold, Zhang explained.
Gains have not been universal. Large losses in the Niger Delta have reduced total mangrove area in western and central Africa since 2010. North America and southern Africa have had broad damage after tropical cyclones tore through wide stretches of mangroves.
“The global successes we’ve seen with mangroves during the past decade should not be seen as grounds for complacency,” Zhang said. He said the findings show that protecting forests and slowing clearing can bring large benefits when natural spread and regrowth are also underway.
NASA Earth Observatory images by Michala Garrison used Landsat data from the U.S. Geological Survey. Adam Voiland wrote the observatory’s account. The global analysis covered imagery through 2023.
