After decades of loss, the world's mangrove forests have reached a turning point. A 40-year satellite study published in Science found that since around 2010, gains have nearly matched losses, and a separate global map now shows a small net increase.
A Turning Point Hidden in Satellite Data
For most of the 20th century, mangrove forests were vanishing. Coastal development, aquaculture, and agriculture chewed through some of the most productive ecosystems on Earth, the nurseries of the sea, the storm shields of coastlines, the carbon vaults of the tropics.
In June 2026, a study published in the journal Science changed the story.
Researchers at Tulane University, using four decades of Landsat satellite images, found that since around 2010, mangrove gains worldwide have nearly matched losses. A separate global map, the Global Mangrove Watch update released in July 2026, found a small net increase of 477 km² in mangrove cover since 1985.
>> "Our study doesn't mean that mangroves are totally healthy globally."
- Dr Zhen Zhang, Tulane University
What the Numbers Show
Between the 1980s and 2023, total global mangrove area declined by just about 1%, with most of the loss, nearly 3,000 km², happening before 2010. Since then, gains have nearly kept pace with losses, driven mostly by mangroves expanding into new areas.
Mangroves expand naturally along coastlines where conditions allow, advancing into newly formed mudflats, recovering after deforestation slows, recolonising degraded shorelines. Where human pressure has eased, they return.
Why Mangroves Matter More Than Almost Anything
Mangroves are among the most carbon-dense ecosystems on Earth, and lead author Zhen Zhang says they may hold four or five times more carbon than tropical rainforests. They protect coastlines from storms and sea-level rise, and they are vital nurseries for fisheries.
Losing them is catastrophic. Getting them back is one of the clearest wins the ocean and the climate can share.
The Threat That Remains
Sea level rise, if it accelerates beyond certain thresholds, risks drowning mangroves faster than they can migrate landward. Their carbon stores, built over centuries, could be released in decades.
But the trajectory is real. The loss is slowing. In many places, it has reversed. Forty years of satellite data do not lie.
_Sources: Zhang, Z., Murray, N.K., et al., "Unexpected expansion and regrowth in Earth's mangrove forests over the past four decades", Science, June 2026. Elizabeth Schell, "Can globally essential mangroves bounce back from deforestation? New study gives hope", Mongabay, 23 June 2026. Samuel Ogunsona, "Mangroves gain ground globally, marking turnaround after decades of loss", Mongabay, 14 October 2026._