Key facts
Only One members are supporting the cultivation of 50,000 mangroves in northeast Tanzania’s Pangani District, just south of the Kenya–Tanzania border.
This project is restoring five hectares of land degraded by salt mining, seaweed farming, and deforestation for mangrove timber.
Eight mangrove species endemic to East Africa are being cultivated. The region is losing an estimated 3,000 hectares of mangroves each year.
How the project works
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During low tide, mangrove nursery workers collect soil from nearby mudflats to fill bags for seed germination.
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Germinated seedlings and propagules are moved to nursery beds, where they are watered, shaded, fertilized, and protected from pests.
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After several months, multiple leaves grow, the roots strengthen, and the propagule matures — reaching a height that varies by species but generally exceeds six inches. At this stage, planters wade into knee-deep mud to relocate them into restoration sites, planting them at depths of about one-third their length.
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Once established, veritree monitors forest health and success rates using field observations (via the Collect App), cameras, drones, and remote sensing.
Project impact
All projects on Only One help save the ocean and the planet, with 100% of our members’ funds going directly to impact. Keep reading to learn how our project, “Reviving ecosystems across coastal Tanzania” is making a positive difference.
Ecosystem value
East Africa’s coastal mangroves — which make up a quarter of Africa’s total — face numerous threats. Climate change is driving sea-level rise and salinization, while urbanization and agriculture have resulted in mass deforestation.
Counting both terrestrial and marine trees, the planet has lost almost one billion acres of forests in the last 35 years alone. That includes mangroves, among the most resilient plants — able to withstand waters with salt levels 100 times higher than those fatal to most other species. In 2024, the IUCN’s first global mangrove assessment found that more than half the world’s mangroves could be gone by 2050.
Such a decline would carry catastrophic consequences for the region and beyond. Mangroves are exceptional carbon sinks — five times more efficient than terrestrial trees — storing carbon in their roots and soils for millennia. They also serve as frontline defenders against hurricanes and heavy weather, shielding coastlines by dampening wave action and fortifying the land-water frontier.
Healthy mangrove ecosystems sustain both wildlife and people: their twisting roots shelter shorebirds, crustaceans, rays, turtles, and fish, making them essential fishing grounds.
Mangrove timber, though valuable as a building material, has been overharvested beyond sustainable limits — underscoring the urgency of veritree’s work to increase mangrove extent and resilience.
Biodiversity
It’s estimated that 1,500 species call mangroves home — 44% of which are at heightened risk of extinction, including about half of all mangrove-dwelling mammals and a quarter of mangrove-dwelling fish species.
In Tanzania, a range of intertidal and forest species flourish along the brackish waters of the western Indian Ocean: eels and hongwe (catfish) weave among the roots, endangered dugongs feed along the bay, and white-throated monkeys move through the branches. Malachite kingfishers, with their gemstone-green crest plumage, perch within the foliage.
This project involves planting eight mangrove species to maximize regional resilience, the most common of which is the Mchu (grey or white mangrove).
Project calculations
veritree’s dashboard provides quick, back-of-the-envelope calculations to help contextualize the impact of the newly planted trees.
Only One members are planting 50,000 mangroves, with a density of about 10,000 trees per hectare (~107,639 square feet). If we assume the average studio apartment is about 600 square feet, these mangroves could fit inside 895 apartments!
Assuming a maturity rate of 80%, and each mangrove sequestering 0.31 tonnes of CO2 (12,400 tonnes in total), the 50,000 trees balance out the emissions of 2,695 cars every year (average car in North America: ~4.6 tonnes of CO2/year).
Community development
The veritree team works with local restoration group Earth Lungs as a planting partner, employing community m
embers who carry out 100 days of work to plant these 50,000 trees. Beyond planting, veritree and Earth Lungs train and empower community members in monitoring and reporting, supporting long-term ecosystem management.
Across Tanzania, the planting team employs 125 part-time and 81 full-time staff — 64% of them women, who lead nursery teams and oversee the reforestation process.
Sustainable Development Goals
By supporting the “Reviving ecosystems across coastal Tanzania” project, funds from Only One members contribute to advancing these three United Nations Sustainable Development Goals (SDGs).
Project reporting
veritree will send Only One quarterly reports on the progress of the mangrove planting project, supplemented by live digital dashboard updates detailing the total number of mangroves planted, their health status, and ongoing conservation work.
More about our mangrove restoration partner
veritree spun out of the sustainable clothing brand tentree to incentivize businesses and individuals to pursue Nature-based Solutions (NbS) and restore ecosystems at scale. veritree works with planting organizations across the globe to verify NbS projects, beginning with work in in Canada, Kenya, Madagascar, the United States, and Tanzania, with plans to expand further. Ten percent of funding goes toward ground-level monitoring (years 1–5, when trees are most vulnerable), later transitioning to remote sensing technology (year 5 onward) as part of a holistic, multiphase approach to long-term progress tracking. Beyond funding, veritree partners closely with local communities to showcase the immense value of newly planted forests, fostering pride and ownership that ensures restored forests not only survive, but thrive.
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