WORLDTECHGlobal Mangrove Forests Rebound After Decades of Decline, Landsat Study Finds
Mangrove forests, which shrank for decades, have been expanding across much of the world since around 2010, according to research published in Science and presented by NASA Earth Observatory. The authors draw on Landsat satellite imagery, and say the shift marks a turnaround for a forest type long defined by loss.
Landsat imagery tracks changes in canopy
The researchers examined Landsat imagery gathered between 1984 and 2023, searching for shifts in how far mangrove canopy extends and how densely it grows. Satellites have been used to map mangrove forests since the 1970s, beginning with the launch of the first Landsat craft. NASA Earth Observatory's paired images set a Thematic Mapper scene from February 14, 2010 against an OLI scene from February 2, 2026, captured by Landsat 9.
Losses before 2010 gave way to gains
Between 1984 and 2010 the researchers counted losses of nearly 3,000 square kilometers (1,200 square miles). After 2010 they logged an unexpected rise of nearly 2,000 square kilometers (770 square miles) in mangrove cover, driven by growth in Asia, Australia and South America.
The authors attribute about two-thirds of that expansion to mangroves taking hold in new areas, with the remaining third coming from restoration and regrowth in degraded zones. Many current mangrove stands also have denser, more closed canopies than they did in 2010, which the researchers read as evidence of healthier, less degraded forest, particularly in South America.
Burma records one of the sharpest reversals
Burma (Myanmar) offers one of the clearest cases. The country lost mangroves quickly during the 1980s and 1990s as farming, aquaculture and firewood collection spread along its coast. Around 2010 that pattern reversed, and mangrove area began to grow in many locations. The authors credit the change to heightened awareness and restoration work after the 2004 Indian Ocean tsunami, tougher legal protection for forests, and heavy sediment deposition that created new mudflats for colonisation.
In Palaw Township in Burma's Myeik District, regrowth is visible in abandoned rice fields south of the village of Kyauktaung, where mangroves have replaced rice cultivation. Conservation projects and tree planting on nearby Pyin Bukyi Island are also mentioned. Burma lost 28.6 percent of its mangrove area between the 1980s and 2010, and has since regained about 10 percent.
Gains are uneven across regions
Deforestation remains a persistent problem in Burma, and the researchers note that in some places losses still exceed gains. Other research groups have tracked long-term change in selected regions, but the authors describe these as the first global mangrove maps covering so long a period, according to Zhen Zhang, an environmental scientist at Tulane University.
Open questions
- Will the post-2010 gains in mangrove area and canopy density hold?
- Which areas where losses outweigh gains are still shrinking?