The rhythmic sound of voices singing in harmony floats across Mozambique’s Limpopo River as several women stand ankle deep in the sticky mud along its banks.

In a well-rehearsed routine, one woman scoops up sediment with a hoe while another buries a fragile mangrove sapling in the void.

The joyous songs of the women obscure the difficulty of their job.

“It’s hard work, because we work in the mud,” said Josefina Augusto Boca, 42.  “But we don’t mind it because we know its importance. We know it’s for the benefit of our community.”

Boca is one of 22 women involved in an effort to replant mangrove trees in the Mahielene-Xai Xai district, which is some 200km north of Mozambique’s capital, Maputo.

The project, which is led by the United Nations Environment Programme (UNEP) and funded by the Global Environment Facility, is aiming to revive the district’s once-thriving mangrove forests, many of which have fallen victim to logging and cyclones.

The project’s backers are hoping the mangroves – which thrive in the salty waters of coastlines and estuaries – will create a buffer around local communities, shielding them from storm surges and other extreme weather linked to the climate crisis.

“As cyclones in the Indian Ocean get stronger, they will cause ever greater destruction and loss of life unless we invest in nature-based solutions, like mangroves, to shore up coastlines,” said Leticia Carvalho,  Head of Marine and Freshwater at UNEP. “Projects such as this one, which focus on reviving natural infrastructure, are critical to protecting both people and nature as we enter an uncertain climate future.” 

Africa’s 30,500km coastline is especially vulnerable. Fringed with fragile ecosystems, including mangroves, lagoons, deltas, wetlands, seagrass meadows, kelp forests and coral reefs, it faces risks from rising seas and extreme weather.

Mozambique is a case in point. In recent decades, the country has experienced powerful storms, such as Cyclone Idai in 2019 and Cyclone Freddy in 2023, that have resulted in widespread destruction of infrastructure and the displacement of populations.

Along the Limpopo River, residents have long harvested mangrove wood for building and heating. This, combined with pollution, has taken a heavy toll on a fragile ecosystem that binds the land and sea. So have natural disasters, which experts say often pose the biggest threat. Cyclone Eline, which battered Mozambique in February 2000, wiped out nearly 60 per cent of the mangroves that surrounded the Limpopo River estuary.

Two decades later, the destruction continues to be felt by residents who rely on many of the estuary’s natural services. Fisher Ilidio Samuel Chavele, who has plied the Limpopo River for decades, said the loss of mangroves left parts of the river without any protection from Mozambique’s sometimes fierce winds, which discouraged fish from reproducing in the area.

“We couldn’t catch any fish,” he said.

The mangrove restoration project

Mangroves are among the world’s most dynamic ecosystems. They protect coastlines from erosion and extreme weather while filtering nutrients and sediments out of water, helping ensure food security for local communities. They are also major stores of planet-warming carbon and provide critical habitats for a wide variety of plants and animals.

Mangroves are vital to sustaining global biodiversity with over 1,500 plant and animal species depending on them. Their unique root systems act like a nursery for many breeds of birds, fish and crustaceans, while protecting eggs from predators and the elements.

UNEP research shows that mangrove ecosystems underpin global and local economies by supporting fisheries, providing other food sources and protecting coastlines. In fact, every hectare of mangrove forest creates up to US$57,000 in ecosystem services, which are the benefits the natural world provides to humans.

However, around the world, mangroves are under increasing threat. They are being destroyed at rates three to five times greater than average rates of forest loss. Over a quarter of the world’s original mangrove cover has already disappeared.

To complicate matters, mangroves grow slowly. It takes over 12 years for a restored forest to begin to function like a natural one. Restoration, while costly, can be effective when an ecosystem has been altered to such an extent that natural regeneration is practically impossible without human intervention.

“It just highlights that we should not degrade the mangroves because it will take a lot of time to get the ecological services back,” said Célia Macamo an ecologist at Eduardo Mondlane University.

Macamo works on the mangrove restoration project, which combines a traditional model of planting and cultivating mangrove seedlings with an innovative technique that uses hydrological restoration to speed up the usually slow process of regrowing mangroves.

“Essentially, you open channels inside the forest, allowing seawater to come in with seedling seeds and propagate and that will help accelerate bringing back the natural conditions of the forest,” explained Macamo.

This is the first application of hydrological restoration in Mozambique, a technique that is now being scaled up to neighbouring countries including Madagascar.

Since the start of this project in 2019, 38 hectares of mangrove forests in have been restored. About 1,000 people, including fishers, women and students, in the area have benefited from the project.

“We are very happy with this mangrove restoration because it breaks the wind and allows fish to reproduce,” said local fisher Chavele while he cleaned his nets after a morning of fishing.  “Prawns for example, they reproduce better in the mangrove, so we would like the mangrove restoration to continue.”

UNEP and the Global Environment Facility have partnered together on the Mangrove Restoration and Livelihood Support through Community Participation in the Limpopo River Estuary project. It falls under the banner of the Implementation of the Strategic Action Programme for the Protection of the Western Indian Ocean from Land-Based Sources and Activities and is executed by the Nairobi Convention.

The UN Decade on Ecosystem Restoration 2021–2030

The UN Decade on Ecosystem Restoration 2021–2030, led by the United Nations Environment Programme, the Food and Agriculture Organization of the United Nations and partners covers terrestrial as well as coastal and marine ecosystems. A global call to action, it will draw together political support, scientific research and financial muscle to massively scale up restoration.

This blog was originally published by UNEP