Carbon sinks rich with life
Mangroves thrive at the land–sea boundary. Their aerial roots create habitat for juvenile fish, crabs and prawns, which then spill into nearby reefs and open water. Studies show mangroves support billions of juveniles yearly, boosting catches and food security. They are also blue-carbon workhorses: around 1,000 tonnes of carbon per hectare is stored, mainly in deep soils. At landscape scale, mangroves filter sediments and nutrients, improve water clarity, and stabilise shores. The IPCC stresses their role in protecting biodiversity and coastal food systems while reducing risk for human populations.
Role in reducing coastal erosion
Mangroves prevent erosion by dissipating wave energy. Roots and stems slow currents, causing sediments to settle and bind the shoreline. Research shows wave-height reductions of 13–66 percent over the first 100 metres of mangrove. Storm surges are also reduced, especially across wider belts that extend for kilometres. Dense mangrove stands can halve shoreline erosion, while in Thailand plantations show root mats enhancing stability by locking in sediments. A simple rule from coastal engineers applies: wider, denser forests provide more protection, though even narrow strips make a difference when combined with seawalls or levees in hybrid designs.
Mitigating the effects of rising seas
Mangroves also help communities adapt to sea-level rise. In the short term, they reduce flood extents and damages by lowering wave and surge levels. Globally, this equates to protection for over 15 million people and US$65 billion in avoided flood damage annually. Over the longer term, mangroves can keep pace with moderate sea-level rise by trapping sediments and building soils.
Studies suggest a threshold of around 7mm per year; beyond this rate, mangroves struggle to maintain elevation. Where sediment supply is disrupted by upstream dams, or where coasts are hardened with infrastructure, mangroves lose their ability to migrate inland and eventually drown in place. Planning for inland migration and reconnecting sediment pathways improves their resilience.
Value for coastal communities
Mangroves are the most cost-effective defence for many lower-income coasts. More nursery habitat means more fish and invertebrates reaching catchable size, and surveys show households near mangroves eat more aquatic foods. They also provide opportunities for climate finance: measurable soil-carbon stocks enable credible blue-carbon projects that can fund conservation or restoration. Beyond these global values, mangroves offer local benefits such as fuelwood, honey, timber and ecotourism. Nevertheless, their strongest and most consistently measured contributions remain risk reduction, carbon storage and fisheries support.
Limits and caveats
Mangroves are not invulnerable. Protection weakens where belts are narrow, degraded or fragmented, or where deep water reaches the forest edge. Extreme surges can overwhelm them, and rapid sea-level rise without sediment or space will drown forests. This means they should be seen as a key line of natural defence, but not as a cure-all.
The reality in Phuket and Thailand
Tourism development fragments or clears mangroves, cuts off tidal flows, and hardens shores. This accelerates erosion, increases wave energy at the shoreline, and blocks mangroves from migrating inland. In Phuket, resorts, marinas and roads have squeezed mangroves, prompting high-profile prosecutions near Sirinat National Park and other protected tracts. Similar cases have been recorded at Khlong Mudong and Ao Kung, where local opposition has focused on the risks to mangroves and fisheries. The national picture reflects major historical losses in the late 20th century, partial recovery since, but continued pressure in tourism hubs.
Why this matters
Along Thailand’s Andaman coast, shorelines shift between retreat and accretion depending on waves, sediments and human actions. Removing or narrowing mangrove fringes tips the balance toward retreat by exposing fine sediments to wave attack. While mangroves can keep pace with moderate sea-level rise, hard tourism infrastructure blocks their landward migration, raising the risk of loss. The IPCC identifies this process – known as coastal squeeze – as a major driver of future wetland decline worldwide. For Phuket, where the economy depends on beach tourism, the erosion of natural protection increases vulnerability to both storm events and gradual sea-level rise.
Bottom line for Phuket
Phuket’s tourism economy depends on clean beaches and calm bays. These, in turn, depend on mangroves that damp waves, trap sediment and buffer surges. Clearing or squeezing mangroves for hotels, roads and marinas increases erosion risk now and limits adaptive space as seas rise.
Solutions are straightforward: keep and widen mangrove belts, design waterways to reduce energy, and enforce zoning laws that already exist. Where these steps are taken, natural processes maintain resilience. Where they are ignored, coastal risk increases sharply.
Finally, take a walk at Tawanron Beach or over the boardwalk at Saphan Hin to see firsthand why nurturing mangroves is vital for Phuket’s future.
Looking ahead, the management of mangroves in Phuket and Thailand will require balancing tourism growth with ecosystem conservation. This means not only protecting existing mangrove belts but also planning restoration projects in degraded zones. Reforestation has been attempted in many provinces with varying success, but lessons show that restoring tidal flow and sediment supply must come before planting.
For Phuket, where tourism dominates the economy, mangroves can be marketed not as obstacles to development but as assets that protect beaches, fish stocks and property. Coastal planning that integrates natural defences with built infrastructure offers a resilient path forward. In a changing climate, mangroves are not optional extras: they are frontline protection, and their loss would leave both people and businesses more exposed to risk.