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Mangroves stage unexpected recovery worldwide
The world's coastal mangrove forests, critical for storm protection and carbon storage, have reversed decades of decline, a new scientific study reveals. Researchers attribute the turnaround to stronger legal protections, public awareness, and the forests' natural ability to regenerate once destruction stops.
Decades of destruction
Mangroves, known for their dense root systems, have long served as natural barriers against storms and tsunamis while storing up to five times more carbon dioxide than terrestrial forests. Their roots also provide vital nurseries for marine life, shielding young fish from predators.
Yet, over the past century, these ecosystems faced severe threats from fish farming, agriculture, and urban expansion. Between the 1980s and 2010, more than 12,000 square kilometers-an area roughly the size of Jamaica-were cleared across Asia, Africa, and the Americas.
Reversal driven by policy and nature
The study, published this week, shows a net gain in mangrove coverage since 2010. Total losses since the 1980s have now shrunk to approximately 849 square kilometers, a fraction of earlier figures. While restoration efforts contributed, the primary driver was natural regrowth in areas where deforestation had slowed.
Indonesia and Myanmar, two countries with the highest mangrove density, saw notable recoveries. In Indonesia, the 2004 Indian Ocean tsunami highlighted the forests' protective role, prompting reduced clearing for aquaculture. "Some islands remained intact thanks to mangroves, raising public awareness," said lead author Dr. Zhen Zhang of Tulane University.
Myanmar's shift followed Cyclone Nargis in 2008 and a 2016 logging ban, which further curbed deforestation.
Technology reveals hidden growth
Advanced satellite imagery from the Landsat program played a key role in the findings. Unlike previous assessments, the system detected subtle canopy changes, revealing far more new growth than earlier studies. "This marks a significant improvement in global monitoring," said Prof. Elizabeth Robinson of the Grantham Research Institute, who was not involved in the research.
Mixed outcomes and lingering threats
Not all growth is unequivocally positive. In Brazil and other nations, expanding mangroves along nutrient-rich coastlines may stem from upstream deforestation and mining, which wash sediments into rivers. "This is good for mangroves but raises concerns about ecological trade-offs," noted co-author Dr. Pete Bunting of Aberystwyth University.
West and Central Africa remain hotspots for destruction, with Nigeria's Niger Delta suffering severe pollution from oil pipelines. Tropical cyclones also pose a persistent threat, causing sharp annual losses in regions like Australia and the Caribbean.
Despite these challenges, the study's authors emphasize progress. The proportion of dense, carbon-rich mangrove canopies has increased by nearly 20% since the 1980s. "We're moving in the right direction," Zhang said.
Healthier forests ahead
The findings underscore the resilience of mangroves when given the chance to recover. While global efforts must continue, the study offers a rare environmental success story amid broader ecological concerns.
