Ghost Carbon in the Mangroves — the Livelihoods/Océanium Restoration Programme in Senegal's Saloum & Casamance Deltas

Starting in 2008, the Senegalese NGO Océanium de Dakar partnered with the Livelihoods Carbon Fund (financed initially by Danone) to replant mangroves across the Saloum and Casamance river deltas, mobilising an estimated 350 villages and 100,000 people to plant about 79 million mangrove propagules over more than 10,000 hectares. The programme, often described as the world's largest mangrove restoration effort, was structured as a 20-to-30-year voluntary carbon-credit scheme, with roughly 500,000 credits sold towards a projected 0.5 million tonnes of CO2-equivalent sequestered over its lifetime.
Independent peer-reviewed research (Andrieu et al., 2020, Forest Ecology and Management) used historical satellite imagery to separate planted from naturally regenerated mangrove and concluded that about 96% of the observed regrowth between 2009 and 2012 was spontaneous, linked to a post-drought rainfall recovery, rather than attributable to replanting; the study reported only 18.3–20.5% survival among trees that were actually planted, with roughly 36% of monitored plots failing outright, and cited sites planted up to 9 kilometres from the nearest tidal channel where mangrove could not establish.
Subsequent investigative reporting drawing on the project's own monitoring reports estimated that around 168,000 of the credits sold (roughly a third) had no supporting environmental benefit, partly because a later monitoring report raised assumed soil-carbon values by nearly 40% without new field evidence, and because the monitoring contractor had assumed 100% survival of planted trees despite the low measured survival rate. The same reporting found only about 5.2% of programme spending reached local communities directly. The case is included here as a documented cautionary example of the monitoring, reporting and verification failures that can undermine blue-carbon PES schemes even at very large scale, rather than as a model to replicate uncritically.

Read the full analysis: https://www.thenewhumanitarian.org/feature/2017/12/18/jury-still-out-huge-mangrove-regeneration-project-senegal