A RECENT study of the sea defences around the Gulf of Tonking in northern Vietnam highlights the role of mangroves in strengthening the coastal defences. Researchers from the University of East Anglia, UK, and the Mangrove Ecosystem Research Centre in Hanoi, said that planting mangroves on coasts is more effective than building concrete walls to keep floods and storms at bay. Vietnam, with a 3,000-km long coastline, lies in one of the most active tropical storm regions in the world. Over the past 20 years, storms have taken the lives of thousands of people in the region.

In most countries in Southeast Asia, mangroves are being destroyed to make room for shrimp farms. Mangroves stabilise the seafloor, trap sediments and reduce the angle of the seabed's, slope, which helps to minimise the energy of breaking waves, protecting existing sea walls. Besides, mangroves bring benefits to local communities. They support coastal fisheries by providing nutrients and sheltered spawning grounds among their flooded roots and branches. They also provide honey and timber.