From a simple KSh. 390 contribution grows not just a mangrove tree, but a powerful new model for climate finance – one rooted in equity, ecology, and economic resilience.
By Ethical Business Staff Writer
In Marereni, a small village on Kenya’s northern coast, hope is taking root among the mangroves. Once worn down by overfishing and creeping coastal erosion, the community is now restoring its forests and future – reviving hope with every tide-bound root. It is a story of local ingenuity and environmental repair, where replanting is not just reviving ecosystems, but livelihoods.
Here, just KSh. 390 (US$3) buys more than a seedling. It buys equity in a new climate economy. That small amount purchases a “biodiversity block,” a microcredit unit that funds the planting of a mangrove tree. But the real return goes far beyond carbon capture. It’s about biodiversity, livelihoods, and resilience.
A new climate economy, grounded in community
The transformation in Marereni is being driven by an innovative biodiversity credit scheme launched by U.S.-based conservation group Seatrees, in collaboration with Ocean Ledger, local NGO Community Based Environmental Conservation (COBEC), and the people of Kilifi County. The Marereni Kenya Biodiversity Block, the first of its kind, is restoring 640 hectares of degraded mangrove forest.
With 300,000 biodiversity credits already sold – raising over KSh. 117 million (US$900,000)—the project is a flagship for how small contributions from individuals and organizations around the world can power local solutions to climate and ecological crises.
For fisherman Gona, one of the 640 community members employed by the initiative, the benefits are tangible. “Restoring and planting mangroves helps boost fish populations, which means better catches—and a better income for people like me,” he tells Mongabay.
With a planting pace of 30,000 trees per month and an impressive 80% survival rate, Marereni is leading a grassroots revolution in coastal restoration.
Beyond carbon: Centering biodiversity
What sets the Marereni model apart is its focus on biodiversity credits, not just carbon. While many climate finance projects revolve around emissions reductions, this approach recognizes the broader value of restored ecosystems.
Mangroves serve as breeding grounds for fish, stabilize coastlines, and protect against storm surges. They are, in every sense, ecological lifelines. Yet according to the UN Environment Programme, ocean ecosystems receive only 4% of global conservation finance.
By turning biodiversity into a measurable and tradable asset, the Marereni project fills that funding void. Each credit funds a tree, but also supports local jobs – especially for women, who manage nurseries, lead planting teams, and use earnings to build small businesses like maize milling or goat farming.
“This is the kind of climate finance that respects both nature and people,” said Dr. Esther Njenga, a Kenyan climate policy analyst, speaking to Ethical Business. “It’s inclusive, low-cost, and high-impact.”
A legacy of coastal innovation
Marereni’s progress did not start from scratch. It builds on the legacy of earlier Kenyan projects like Mikoko Pamoja in Gazi Bay, the world’s first community-led blue carbon credit scheme launched in 2012. That effort, followed by the Vanga Blue Forest in 2019, proved that local conservation can generate revenue while restoring nature.
Together, these earlier efforts earned close to KSh. 26 million (US$200,000) through verified carbon credits, which were then reinvested into clean water systems, schools, and health services.
But where Gazi and Vanga focused on carbon, Marereni has expanded the model—prioritizing biodiversity and ecosystem health, not just atmospheric gains. It is a more holistic take on climate finance – one that values marine nurseries, ecological buffers, and community well-being alongside carbon metrics.
Impact on incomes and resilience
The change in household economics is striking. Before the mangrove project, Marereni’s fishermen earned under KSh. 520 (US$4) per day. Today, their incomes can reach KSh. 1,010 (US$7.75) – a near doubling, made possible by healthier fish stocks and more productive coastal ecosystems.
The economic gains also reach beyond the water. Women working in nurseries are investing in livestock, farming tools, and family businesses – building a foundation for long-term resilience. Unlike conventional aid programs that can foster dependency, this model supports autonomy and durable development.
Importantly, the initiative includes a 10-year monitoring plan. The first formal biodiversity assessment begins in October 2025, with results expected in early 2026. Sustainability isn’t an afterthought; it is built into the project’s DNA.
Technology meets tradition: monitoring the future
One of the project’s most forward-thinking aspects is its embrace of cutting-edge monitoring tools. Traditional GIS systems often struggle to accurately capture the complexity of mangrove environments. To overcome this, Seatrees partnered with Ocean Ledger, a remote sensing and geospatial analytics firm, to integrate machine learning and satellite imagery into the project’s biodiversity credit methodology.
Between March and July 2024, Ocean Ledger analysed high-resolution satellite data across 600 square kilometers of coastal landscape. Using machine learning models trained on LiDAR-derived canopy height, mangrove extents, and above-ground biomass measurements, they established detailed ecological baselines.
The result: a dual verification system, combining local knowledge and fieldwork with satellite-derived metrics. This hybrid approach ensures cost-effective, transparent, and scalable tracking of forest health and credit legitimacy.
Ocean Ledger also validated its data by comparing it to field samples, finding strong correlations between satellite-predicted canopy height and actual biomass – further enhancing confidence in the methodology.
Environmental and climate benefits
Beyond economic uplift, the environmental impacts are substantial. The restored mangroves buffer against rising seas, reduce storm damage, and offer critical habitat for marine species. Fish populations are already rebounding.
Each 30 trees planted are projected to sequester approximately nine tons of CO₂ over 25 years. That makes the project a meaningful contributor to climate mitigation – without falling into the trap of “carbon tunnel vision.”
The project also lays the groundwork for a mangrove condition methodology, currently being developed with global NGO Accounting for Nature. The goal: to create science-based verification standards that could guide future biodiversity markets.
The need for policy and regulation
But even as innovation accelerates, regulation lags behind. Biodiversity credits operate in what many experts call a “regulatory gray zone.” Like early carbon markets, they lack unified standards, valuation frameworks, and verification protocols.
A 2023 Guardian investigation into carbon offsets reignited concerns about market credibility. Without strong governance, such systems risk overpromising and underdelivering. In Kenya, there is currently no national framework for blue carbon or biodiversity credits, a policy vacuum that could jeopardize the sector’s growth.
“We need policy to catch up with innovation,” Dr. Njenga emphasises.
“These community-led successes are outpacing the systems that are supposed to support them.”
There is some hope on the horizon. The Africa Carbon Markets Initiative, launched in 2022, aims to bring continent-wide coordination to carbon finance. But biodiversity-specific standards remain thin, and urgent work is needed to ensure credibility, scalability, and local benefit.
A global proof of concept
At its core, Marereni’s initiative is a story about rethinking conservation finance. It proves that with the right incentives, environmental restoration can be locally led, socially equitable, and ecologically sound.
It is not just a Kenyan success story – it is a blueprint for a new kind of climate finance. One that is decentralised, inclusive, and rooted in the real-world priorities of those most vulnerable to environmental breakdown.
As mangroves return to Marereni’s shores, they carry with them the promise of a resilient future – not only for the village, but for coastal communities around the globe.
At Ethical Business, we track solutions that work not just for profit or policy, but for people and planet. Marereni’s mangrove project is one of those rare cases where all three converge – and that is worth watching.
