After Decades of Loss, the World's Mangrove Forests Are Growing Back
For 26 years of satellite records, the world's mangrove forests shrank. Between 1984 and 2010 they lost nearly 3,000 square kilometers (1,200 square miles), NASA Earth Observatory reports. Then the count turned. After 2010, mangroves gained nearly 2,000 square kilometers (770 square miles).
Those figures come from a study led by Tulane University and published in Science on June 4, 2026. Zhen Zhang, a postdoctoral scholar at Tulane's School of Science and Engineering, led the work. The team read Landsat imagery from 1984 to 2023. Landsat is the NASA and U.S. Geological Survey satellite series that has photographed Earth since the 1970s. The researchers tracked two things: how much ground mangroves covered, and how dense their canopy grew. "After decades of loss, we're finally seeing a global turning point for mangroves," Zhang said in the Tulane release. NASA Earth Observatory featured the finding on November 13, 2026.
Where the new forest came from
The rebound began around 2010 and ran strongest in Asia, Australia and South America. Zhang told NASA that about two-thirds of the expansion came from mangroves colonizing new areas. The other third came from restoration and regrowth in degraded areas.
Much of that colonizing happened where rivers drop sediment. Around the mouth of the Amazon River and in northern Australia, heavy deposits built new mudflats, and mangroves moved onto them, adding area steadily in both regions since the 1990s. At the northern and southern edges of the mangroves' range, including the southeastern United States, warmer temperatures and fewer freezes let the trees push into ground that used to run too cold.
Standing forests changed as well. Many mangrove forests now carry denser, more closed canopies than they did in 2010. NASA calls that a sign of healthier, less degraded forest, most of all in South America.
Burma's turnaround
Burma (Myanmar) shows the swing up close. The country cleared mangroves fast in the 1980s and 1990s for farms, aquaculture (fish and shrimp ponds) and firewood, and lost 28.6 percent of its mangrove area between the 1980s and 2010. Since then, its mangrove area has grown about 10 percent. For Burma, the study's authors credit three forces: more awareness and restoration work after the 2004 Indian Ocean tsunami, stronger legal protection for forests, and high sedimentation that opened new mudflats.
Two Landsat images of Palaw Township in Burma's Myeik District, taken on February 14, 2010 and February 2, 2026, show the change from orbit. Mangroves spread along the coast between the two dates, and the farmland beside them shrank.
Why a short tree carries this much weight
Mangrove trees average about 13 meters (43 feet) tall. Even so, mangrove ecosystems store up to four times as much carbon as taller inland tropical forests, according to NASA. Their stilt-like roots give fish, shrimp, crabs and other marine life shelter and nursery grounds. The forests also protect coastal communities from erosion and storm surges.
Where the rebound stops
The global total hides regions still moving the other way. Substantial losses in the Niger Delta have cut total mangrove area in West and Central Africa since 2010. Tropical cyclones have degraded broad swaths of mangroves in North America and southern Africa.
Area also differs from maturity. The Tulane release notes that newly established mangrove forests are often young and do not yet give the full ecological benefits of mature ones. And the rebound has not yet made up the whole loss. By 2023, global mangrove area still sat about 1 percent below where it stood in the 1980s, by the release's count.
📍 Multiple Perspectives on the Story
Forty years in one global map
Earlier long-term studies tracked mangroves in selected regions. Zhang told NASA these are the first global mangrove maps to cover such a long stretch of time. Thomas Worthington, head of the Global Coastal Wetlands Lab at the University of Cambridge, worked on the study with the Tulane team. Worthington says the satellite record also helps pick out places that need conservation action and places where restoration could help.
Old ponds filling back in
In many regions, mangroves are recolonizing abandoned aquaculture ponds, according to the Tulane release. Rates of degradation have dropped significantly since the 1980s, and the release ties that drop to conservation policies and restoration programs. Daniel Friess, who directs The Mangrove Lab at Tulane, describes a net global increase alongside slowing degradation.
Rice fields gone back to forest
In Palaw Township, much of the regeneration appears to be happening in abandoned rice fields south of the village of Kyauktaung, NASA reports. People on nearby Pyin Bukyi Island have run conservation projects and planted trees to support the mangroves. The pressure has not lifted. Deforestation remains a common challenge in Burma despite the gains.
Carbon kept, and carbon added
In the Tulane release, Zhang says clearing mangroves sends large amounts of long-stored carbon into the atmosphere, while forests left standing keep adding carbon over time. Protection pays twice: emissions avoided now and storage later. Closed-canopy forest holds more carbon than thin, degraded stands, so the release says the canopy gains suggest mangroves may be capturing more carbon than scientists had recognized.
One study, rewriting older numbers
This is a single study, and it revises the record. The Tulane release calls the four-decade net loss much smaller than earlier estimates. The paper itself could not be read for this article, so the figures here come from NASA and the release, and those two differ slightly on the loss: nearly 3,000 square kilometers from 1984 to 2010 in NASA's account, nearly 2,900 from the 1980s to 2010 in the release. Much of the colonizing rode on river sediment and milder winters, which no conservation program controls. Those gains can reverse fast. Texas mangroves spread for decades, then declined sharply after an extreme freeze in 2021.
What is known and what is still open
The satellite record settles the direction. After 26 years of loss, mangroves have gained ground since 2010, mostly by spreading onto new mudflats and warmer coasts, with restoration and regrowth supplying about a third. Many standing forests grew denser in the same years. Zhang told NASA the past decade's successes "should not be seen as grounds for complacency."
Three questions stay open: whether young forests grow into the carbon stores and storm buffers that older ones became, whether the gains hold through freezes and cyclones, and whether the Niger Delta and other losing regions turn the way Burma did. Zhang names the first step in the Tulane release. The most immediate way to protect mangroves, Zhang says, is to stop deforestation.
Frequently Asked Questions
Are mangrove forests growing back?
Yes, worldwide. A Tulane University-led study in Science found mangroves gained nearly 2,000 square kilometers (770 square miles) after 2010, following losses of nearly 3,000 square kilometers (1,200 square miles) between 1984 and 2010. By 2023, the net decline over the full four decades was about 1 percent.
What is driving the mangrove rebound?
About two-thirds of the expansion came from mangroves colonizing new areas, such as mudflats built by river sediment and coasts that used to be too cold. The other third came from restoration and regrowth in degraded areas.
Why do mangroves matter?
Mangrove trees average about 13 meters (43 feet) tall, yet mangrove ecosystems store up to four times as much carbon as taller inland tropical forests. Their roots shelter young fish, shrimp and crabs, and the forests protect coastal communities from erosion and storm surges.
Where are mangroves still declining?
Losses in the Niger Delta have cut total mangrove area in West and Central Africa since 2010. Tropical cyclones have degraded mangroves across North America and southern Africa, and deforestation remains a common challenge in Burma (Myanmar) despite its gains.