Global mangrove forests recovering, offering hopeful sign for climate and coastal resilience
Mangrove forests, once considered one of the world’s most threatened coastal ecosystems, are showing signs of recovery worldwide, according to new research that finds decades of losses largely offset by regrowth and expansion.
The study, based on four decades of satellite data, finds that mangrove forests worldwide are no longer in net decline and are now growing overall.
After decades of loss driven by deforestation and coastal development, mangroves are expanding in many regions, largely through natural regeneration and expansion into newly formed coastal areas.
The findings suggest a more hopeful trajectory for these ecosystems, which play a critical role in protecting coastlines, supporting fisheries and storing climate-warming carbon.
The research, led by Tulane University in collaboration with Dr Thomas Worthington, Head of the Global Coastal Wetlands Lab at the Department of Plant Sciences, Cambridge, is published today in the journal Science.
Dr Worthington said: “While there are still areas of concern where losses are ongoing, the research highlights a conservation success story. It also shows the power of satellite data helping us identify areas that need conservation action or places where restoration could be beneficial.”
A global turning point for mangroves
“After decades of loss, we’re finally seeing a global turning point for mangroves,” said Dr Zhen Zhang, a postdoctoral scholar at Tulane University School of Science and Engineering and lead author of the study. “This highlights their strong resilience and their potential as a powerful nature-based solution for climate mitigation and coastal protection.”
Mangrove forests declined through much of the late 20th century, losing nearly 2,900 square kilometers between the 1980s and 2010. During the past 16 years, gains have outpaced losses. By 2023, mangrove areas had rebounded, resulting in only about a 1% net decline over the entire four-decade period – a much smaller loss than previously estimated.
“What we’re seeing now is a real shift. Mangroves are now showing a net increase globally, and the rate of degradation is slowing,” said Professor Daniel Friess, Cochran Family Professor of Earth and Environmental Sciences at Tulane and director of The Mangrove Lab.
A combination of restoration efforts and natural processes
The recovery is being driven by a combination of restoration efforts and natural processes. In many regions, mangroves are recolonizing abandoned aquaculture ponds and expanding into newly formed coastal mudflats, especially in river deltas where sediment creates ideal growing conditions.
Beyond increases in area, the research highlights another encouraging trend: many existing mangrove forests are becoming denser and healthier. Closed-canopy mangrove forests, which store more carbon and provide stronger coastal protection, have expanded globally over the past four decades. Rates of degradation have dropped significantly since the 1980s, reflecting the growing impact of conservation policies and restoration programs worldwide.
That growth suggests that mangroves may be capturing more carbon than previously recognized. At the same time, the study shows how vulnerable these gains can be. In Texas, for example, mangroves have expanded in recent decades but experienced a sharp decline in 2021 due to an extreme freeze event, highlighting how climate extremes can quickly reverse progress.
Continued protection is key
Still, researchers caution that the recovery is not complete. Newly established mangrove forests are often young and less capable of providing the full ecological benefits of mature systems. And deforestation remains a threat in some regions, particularly where coastal land is converted for agriculture or development.
The study underscores that continued protection is key to sustaining the rebound.
“The most immediate and effective way to protect mangroves is to stop deforestation,” Dr Zhang said. “When mangroves are cleared, large amounts of long-stored carbon are released into the atmosphere. But when deforestation stops, mangroves can continue to accumulate carbon naturally over time, so there’s a major climate benefit in both avoiding emissions now and allowing future carbon storage.”
Reference: Zhang, Z. ‘Unexpected expansion and regrowth in Earth’s mangrove forests over the past four decades.’ Science, June 2026. DOI: 10.1126/science.aec9773
Image: Mangrove forest by the coast. Credit: Daniel Friess.
Adapted from a press release by Tulane University.
Read the original news item by Jane Durkin, on the Department of Plant Sciences website, 4.6.26