How Kenya's mangrove forests saved a community and themselves

A mangrove forest is a unique, highly productive piece of biome that exists between aquatic and terrestrial environments, between water and earth. File picture: Eric Lafforgue/Reuters

A mangrove forest is a unique, highly productive piece of biome that exists between aquatic and terrestrial environments, between water and earth. File picture: Eric Lafforgue/Reuters

Published May 20, 2021


A fishing community in Kenya has seen a return of dwindling fish stocks and earned money to build a school and clinic and sink boreholes, thanks to a project that helped restore indigenous mangrove forests.

A mangrove forest is a unique, highly productive piece of biome that exists between aquatic and terrestrial environments, between water and earth.

They are groves of trees that are specially adapted to live along coastlines. Their roots can derive nutrition from the marshy soils and the trees can expel excess salt through their glossy leaf system.

The mangrove’s upper trunk and branch systems are above the waterline with the “prop” root systems and the lower trunk usually submerged below seawater at high tide.

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Mangroves are the only tree species that can survive in high salinity environments – seawater. The intricate root systems provide a hospitable and safe habitat for several marine and amphibious species. They trap large quantities of sediments that wash down rivers and are considered ecosystem engineers, creating low salinity habitats which are similar to habitats created by coral reefs.

In Kenya, of the several positive impacts of mangroves, the most important is that mangrove forests’ intricate system of roots and lower trunks provide a nursery for over 180 species of fish that live in the country’s coastal waters. These nurseries allow hatchlings and juvenile fish to grow strong enough to head out into deeper water or move on to coral reefs habitats.

Michael Njoroge, a researcher for the Kenya Marines and Fisheries Research Institute, says: “Fish rarely breed in the deep sea because the conditions are hostile. Fish prefer mangrove environments, so they are protected against predation and strong water currents.”

An article carried by the BBC’s Future Planet in April this year tells a tale of discovery and shared growth of the small Kenyan fishing village of Gazi. Without the forest’s ability to support juvenile marine life, fish populations were plummeting, affecting fishermen who rely on their daily catch to put food on the table.

Eight years ago, Gazi’s mangrove forests were disappearing rapidly. Harvesting of firewood and construction poles saw the area’s forests almost completely depleted. This led to a steep decline in fish stocks which in turn resulted in local fishermen pivoting their careers, resorting to cutting down more indigenous trees to make charcoal to sell in towns and cities.

How did the people of Gazi manage not only to reverse these trends but also grow these protected areas and save their fishing industry?

It was to do with the nature of the mangrove. Apart from being habitat creators, fish nurseries and storm surge buffer zones, these amazing plants are also some of the most efficient at capturing carbon from the atmosphere. One hectare of mangrove forest can capture as much carbon as four hectares of rainforest.

This carbon is transported down the root systems and stored within thick, waterlogged soil.

In 2013 a partnership between coastal Kenyan communities, the Kenya Marine and Fisheries Institute and a Scottish charity launched a project that not only conserved what was left of mangrove forests in the area but grew the footprint of the forests exponentially.

This project was the first of its kind to turn the natural process of storing carbon into an economically viable initiative that would ultimately help communities and the environment.

The idea is simple yet brilliant. The project sells “carbon credits” to industries that find it hard to reduce carbon emissions, such as power utilities, construction companies or mining houses. These credits can be bought as a means of offsetting a business’s emissions.

The first step was to reduce the number of trees being chopped down for firewood and construction material by planting sustainable casuarina trees as an alternative source of wood. The project then trained residents of Gazi in conservation and how to propagate new mangrove trees from seeds.

A community-led initiative saw saplings grown for up to six months in nurseries and then planted directly back into conservation areas. Annually, the project sells 3 300 carbon credits which is the equivalent to taking roughly 650 cars off the roads.

It is a small step toward a greener planet, but it is still a step in the right direction. The success of the Gazi project has led to similar schemes being established in another two coastal fishing villages along the coast. Overall, around 660 000ha of land are used for carbon trading projects in Kenya.

The conservation and restoration of the mangrove forests have led to an increase in fish stocks along the coast and a steady decline in poaching and deforestation.

Omar Mohamed, a local fisherman, has not missed a single mangrove planting session in four years and was among those who planted 4 000 seedlings in November 2016.

“Since we started caring for the mangroves, we’ve harvested more and more fish,” he says. “Now fishermen from as far off as Pemba come to fish here.”

The project has used income from selling carbon credits to build a school, health centre and boreholes for freshwater. By placing a monetary value on conservation, the community has been more inclined to protect and conserve natural resources.

South Africa has 37 estuaries and lagoons where mangroves occur, with the largest forests found along the KwaZulu-Natal north coast. The Kosi, St Lucia, Mfolozi and Mhlathuze estuaries account for about 75% of mangroves, while the Mngazana estuary has the third-largest area.

Kenya is one of the only countries in Africa that has seen an increase in wildlife and protected areas and a decrease in poaching in recent years. Could South Africa take a page out of our northern neighbour’s conservation handbook?

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