The Gulf of Thailand near Koh Kresna now teems with mackerel, sardines, bream, squid, snails, anchovies, crabs and shrimp. “Every day, we are out catching fish and selling them,” says Khiev Sat, longtime leader of Koh Kresna and patriarch of a fishing family. The community fishery is strong — but it wasn’t always that way.
When Khiev was young the nearby waters were largely empty. Across the world, coastal fisheries struggle with declining stocks as climate change, pollution and overfishing reduce marine populations even as demand for seafood grows. Koh Kresna’s turnaround, however, came from restoring one tree: the mangrove.
Mangroves are semiaquatic plants that grow in salty, waterlogged soils. Their elaborate root systems hold them steady against waves and wind and create complex submerged structures that serve as nurseries for young fish and invertebrates. According to a 2024 analysis by governments and biodiversity organizations, mangrove roots support roughly 800 billion young fish, prawns and crustaceans each year. Radhika Bhargava Gajre, a coastal geographer at the National University of Singapore, notes, “The majority of the fishes that we eat are supported by mangroves.”
Beyond providing nursery habitat, mangroves protect shorelines from erosion and storm surge. Studies have shown villages near mangroves suffered far fewer deaths during severe cyclones than those without such protection. Mangroves also excel at trapping carbon: their fallen leaves and branches are buried in waterlogged soils where they decompose very slowly, allowing mangrove forests to store up to four times as much carbon as many other forest types.
Despite these benefits, mangroves face many threats. They are cleared for aquaculture, logged for charcoal, removed for coastal development and stressed by pollution and rising sea levels. The United Nations warns that about half of all mangrove ecosystems are at risk of collapse by 2050.
In Cambodia the loss of mangroves was exacerbated by political upheaval. After the Khmer Rouge era left the economy devastated, many people cut mangroves for charcoal to survive. Without intact mangrove forests, there was little protection for juvenile fish, and local fisheries collapsed. Villages shrank as people left for factories or emigrated to find work.
Over the past three decades, scientists and conservation groups helped spread knowledge about mangroves’ importance. Local fishermen in Cambodia responded. Since 2003, Koh Kresna and neighboring Lok have run a community fishery organization that manages shallow coastal waters, enforces sustainable harvesting, protects more than 145 acres of mangrove forest and leads restoration efforts. In the last two years residents and fishery members planted over 2,000 mangrove saplings with support from organizations including the Red Cross and Landesa. “It is a lot of work. It takes a lot of cooperation between the fishery members, the government and nongovernmental organizations,” says Rusrann Loeng of Landesa.
Cambodia’s community stewards illustrate a broader trend. Global mangrove decline slowed after 2000 as restoration ramped up; a 2023 U.N. analysis found net loss of mangroves decreased by 44% between 2010 and 2020 compared with the previous decade. Conservationists credit community stewardship for much of that progress.
The benefits of mangrove restoration reach beyond local fish catches. Their root systems reduce erosion and absorb storm surge energy, lowering flood risk and saving lives during extreme weather events — protection that will only grow more critical as climate change increases storm intensity. And because mangroves sequester large amounts of carbon in soils, restoring and protecting them contributes directly to climate mitigation. Although mangroves make up just about 0.2% of the world’s forests, they account for roughly 2% of global forest carbon removal, according to analysis by the World Resources Institute.
Young community members in Koh Kresna see the larger impact. “We are helping the whole world,” says 21-year-old fishery member Khiev Chien, noting that their local restoration helps address climate change as well as revive the fishery.
Koh Kresna’s experience underscores how restoring mangroves can revive livelihoods and deliver broader environmental benefits. It’s a labor-intensive process that requires local commitment, coordination with governments and NGOs, and long-term protection, but the results can include thriving fisheries, safer coastlines and meaningful carbon storage. Communities like Koh Kresna provide a model of how nature-based solutions can restore both ecosystems and the human economies that depend on them.