Kenian marine biodiversity credit program restores mangroves — and livelihoods.

The scorching afternoon sun stretches across the semiarid landscape of Marereni, in Kenya’s Kilifi county, where salt and sea shape both the land and the lives that depend on it. Known for its extensive salt mining operations, this remote settlement lies at the heart of the country’s north coast salt belt. Yet beyond the glint of salt pans, Marereni is also home to one of the coast’s most vital ecosystems: a mosaic of fringing, estuarine and creek mangrove forests that support rich biodiversity. This is the stunning backdrop to the site of restoration projects aimed at both revitalising these important mangroves — and the communities that tend to them.

In recent years, Marereni’ s mangroves have been disappearing due to conversion pressure for solar salt works, aquaculture and human settlement, according to information from the Kenyan government’s “National Mangrove Ecosystem Management Plan 2017-27”.

The NMEM plan underscores that the loss of mangrove cover significantly weakens coastal protection, leaving shorelines more susceptible to erosion, storm surges and rising sea levels. This not only heightens the vulnerability of inland areas and infrastructure to climate-related risks but also disrupts vital marine ecosystems, degrading crucial breeding and nursery grounds for fish, crustaceans and other species, leading to declining fish stocks and reduced biodiversity.

Historically, mangrove management in Kenya focused on wood harvesting, neglecting their roles in fishery production, climate change regulation, and shoreline protection. The lack of a sustainable management plan led to deforestation and degradation of mangrove ecosystems.

Delving into the mitigation, The World Bank, through the Kenya Coastal Development Project (KCDP), supported the development of this management plan. Various stakeholders, including government agencies, NGOs, private sector, expert groups, and community-based groups, contributed to the plan’s preparation, coordinated by the Mangrove Technical Committee (MTC

For coastal communities, such as those in Marereni, the loss of mangroves threatens their very livelihoods. Many depend on mangrove ecosystems for fisheries, fuelwood, construction materials and a range of other vital services. As the mangroves vanish, so do economic opportunities, exacerbating poverty and food insecurity in these communities.

Since 2022, a California-based non-profit organisation called Seatrees (formerly known as Sustainable Surf / SeaTrees) has been working with communities in Marereni to restore and protect coastal and marine ecosystems as a natural solution to climate change. This follows similar work the organisation began in 2020 in another coastal location called Mida Creek. Most of Seatrees’ projects globally have been funded through traditional means, including corporate and individual donations and grants. But in 2024, Seatrees started offering donors the option of buying $3 “biodiversity blocks,” each of which represents a single tangible conservation action: planting one mangrove tree on site in Marereni.

Seatrees touts these “blocks” as part of the world’s first marine biodiversity credit program, designed to restore and protect natural marine ecosystems that historically have been relegated to the sidelines of conservation funding. Despite covering more than 70% of the globe and playing a crucial role in regulating the Earth’s climate, the ocean remains an afterthought in global conservation funding. According to a 2022 U.N. report, marine protected areas globally receive approximately $980 million annually — roughly 4% of the $23 billion allocated to terrestrial protected areas each year.

Globally, despite widespread investment in mangrove restoration, survival rates remain low, according to a 2022 study, due to inappropriate site selection, limited community engagement and planting in unsuitable hydrological or sedimentary conditions. Yet Seatrees and their partner COBEC report a survival rate of around 80% for their planted mangroves. According to Julius Sila, a mangrove restoration coordinator and GIS expert at COBEC, this outcome is due to addressing the root causes of degradation before planting begins, matching species to the right site conditions and using scientific assessments such as soil salinity tests to guide planting. “If all these are addressed, success is inevitable”, Julius Sila says.

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