First line of defence 

On 5 June, Saudi Arabia will host World Environment Day 2024, an annual celebration of the planet which this year focuses on land degradation, desertification and drought resilience.    

More than 2 billion hectares of the world’s land is degraded, affecting half the global population and threatening countless species.  

One of the ecosystems under the most pressure are mangroves. These trees thrive along the border between land and sea and are a first line of defence for many coastlines, reducing erosion from storm surges, currents, waves and tides. Their intricate root system makes them attractive to fish and other organisms seeking nurseries, food and shelter. Mangroves support more than 1,500 species, some 15 per cent of which are endangered, found a recent report from UNEP. 

The ecosystem’s protective function was dramatically highlighted by the Indian Ocean tsunami in 2004, which killed more than 30,000 people in Sri Lanka. Parts of the coastline were vulnerable to the tsunami because about one-third of Sri Lanka’s mangroves had been cleared, mainly to make way for shrimp ponds and salt pans. 

Shrimp farming is an important source of employment in coastal communities and of export income for the country. But unsustainable practices can cause a build-up of pollution and disease in the fisheries and many shrimp ponds have been abandoned. 

Nurturing nature 

Following the tsunami, Sri Lanka undertook a mass drive to restore mangroves. However, with hardly any of the plants surviving, the country changed tactics from trying to replant mangroves to better protecting existing mangroves to let them rebuild naturally. 

In 2015, Sri Lanka became the first nation to legally protect all its remaining mangrove forests. It also launched a national programme to restore thousands of hectares that had been lost and appointed an expert committee to provide guidance and make sure that, this time, restoration would work. 

Restoration projects are taking place in coastal districts across Sri Lanka. In some places, researchers are assessing the makeup of potential mangrove restoration sites, including their soil and water quality. That will help conservationists to select the best mix of mangrove species for a particular site, creating the conditions for mangrove forests to rebound. 

This approach is designed to remove the barriers to mangrove growth, which can include suffocation from plastic pollution, and allow nature to “do its wonders”, says Jayakody, who leads the expert committee. 

Multiple gains 

Supported by partners, including the governments of Australia, the United States of America and the United Kingdom of Great Britain and Northern Ireland, this approach has already helped Sri Lanka restore 500 hectares of mangrove since 2015. 

With additional assistance, the country hopes it can still realize its 2030 goal of restoring 10,000 hectares of mangroves – more than 50 per cent of its previous mangrove cover.  

As well as protection against the growing impacts of climate change, such as flooding from sea-level rise and more destructive cyclones, mangroves sequester large amounts of carbon, helping limit human-caused climate change. Mangroves are also an important source of medicine, fish and other food, especially in poorer communities.  

Marcus Tissera, a fisherman from the east coast town of Muthupanthiya, says the restoration initiative has boosted the incomes of many people, both by employing them as boat-drivers, guides and laborers, and by reducing pollution in a nearby lagoon, home to shrimp, crab and fish. 

“There’s a huge benefit from this,” Tissera says, expressing hope that a revival of local ecosystems could also draw more tourists. “Projects like this should be conducted throughout the country. We hope this will make Sri Lanka more beautiful.”