Stretching across the Sine-Saloum Delta and Casamance Estuary, our restoration projects in Senegal span 7,019 hectares of coastline, an area roughly the size of 10,000 football fields.
Between 2020 and 2025, supported by WeForest, local communities planted an estimated 32 million mangrove trees across 17 communes, with agreements signed by mayors and active participation from the people who live and fish in these waters. But planting is just one part. We want to make sure that our mangrove grows and thrive.
It’s not easy to monitor mangroves. Trees grow at the edge of land and sea, where tides rise and fall twice a day. Mangroves are tangled, muddy, and vast, and the seedlings are small. Although we have continuously made efforts to monitor the growth from the ground, the vast number of seedlings, size of the area and mangrove characteristics, makes it challenging to accurately measure the carbon sequestration.
We estimate that the 7,019 hectares of restored mangroves have sequestered approximately 5,192 tCO₂e over the 2020-2025 period, equivalent to the electricity required to power 1,025 average homes for an entire year.
But to verify that carbon, you need data. And to get data at this scale, you need to see from above. That’s where images from drones come in, with their high-resolution images, they can be extremely helpful to monitor the trees we grew and how they are today.
A new perspective
In 2024, WeForest partnered with Earth Geomatique, a Senegalese company specialized in high-resolution aerial imagery. Using drones equipped with advanced sensors, they flew over both entire project areas, capturing images with a resolution of just a few centimeters, making it possible to detect each and every seedling. An amazing improvement from satellite imagery that can only reach resolutions up to 10 meters.
But raw images are not the same as understanding. To translate those terabytes of data into actionable knowledge, we turned to Inverto Earth, a firm with expertise in processing drone imagery for ecological applications. Their algorithms analyzed every single frame, detecting individual mangrove canopies and converting them into precise data points. The result was a map unlike anything we had ever created: a detailed, stratified view of the entire 7,019-hectare landscape, showing exactly where trees were thriving, where they were sparse, and where they were absent.
Adaptive management
The data gave us something essential: the ability to divide the landscape into distinct strata based on canopy density, which is highly correlated to tree biomass. Areas of high density, medium density, and very low density were mapped with statistical rigor. This stratification guided our biomass campaign during 2025 (object of the current verification), and it will continue to guide us for years to come.
Perhaps the most profound gift of this high-resolution data is the clarity it brings to our challenges. Where seedling mortality is high, the drone images leave no room for ambiguity.
Because now we know. And knowing allows us to adapt and improve. This summer and in 2027, WeForest is expected to launch a remediation campaign, focusing replanting efforts where the data shows the greatest need. But we are also going deeper.
In collaboration with local partners, we are installing mini-piezometers (simple instruments that measure water levels and hydrology) to understand the underlying conditions of success and failure. Does the tide flood too frequently? Is the water too saline?
We are also using Digital Terrain Model (DTM) data we acquired for the current carbon verification to better understand the terrain we are growing the trees and we did a Sea Level Rise Analysis that shows the sea level projections for the coming 100 years. We are gathering environmental variables, prospecting in the field, and weaving in community knowledge. We are selecting native species that have survived and will adapt best.
All of this information—drone data, hydrology, terrain models, local wisdom—is now the foundation of a smarter, more resilient restoration strategy.
The bigger picture
For the carbon market, this precision matters. It ensures that every credit we generate is backed by real, measurable impact. Using drone imagery and analyzing the data thoroughly, not only strengthens the credibility of carbon offsets but also builds trust with our many partners. By addressing root causes and improving survival rates, WeForest can scale successful methods, ensuring long-term ecological benefits and a more robust contribution to climate mitigation efforts through reliable, science-driven restoration practices.
Remote sensing and drone images will help us achieve our objectives which are much broader promises than just growing trees. Both Blue Carbon projects focus on: restoring mangroves, sequestering carbon, supporting biodiversity, and strengthening the communities who call this coastline home.
We will continue to restore this area, while making sure we do the best possible job.
