Mangroves as land and ocean buffers: A comparative analysis of mangrove ecosystem services in Ghana and Tanzania

Abstract

Mangroves provide essential ecosystem services, including carbon sequestration, fisheries support, and coastal protection, thereby contributing significantly to climate resilience and coastal livelihoods. Using the Global Mangrove Watch 2020 dataset and the ecosystem valuation technique of benefit transfer, we quantify the value of blue carbon storage and coastal protection in Ghana and Tanzania. The latter is endowed with approximately 110,694 ha of mangroves, which is over six times greater than Ghana's 17,887 ha. Under the Africa-specific primary valuation scenario 150–300 Mg C ha−1, Tanzania's mangroves are estimated to store approximately 92–153 MtCO2e of blue carbon, compared with 11–22 MtCO2e in Ghana. Applying a global carbon price range of US$5–10 per tCO2e, the value of Tanzania's carbon stock would range between US$460–1530 million while Ghana's range between US$57–226. However, these estimated values reflect gross potential and may reduce after accounting for transaction costs and long-term carbon permanence requirements. Sensitivity analyses using global maximum carbon coefficients generated substantially larger potential estimates, emphasizing the importance of regionally calibrated coefficients in blue carbon accounting. Tanzania also has greater restoration potential and annual CO2 capture, indicating higher climate mitigation capacity of the country's mangroves. Despite Tanzania's larger mangrove extent, Ghana's mangrove forests provide higher coastal protection, valued at $121 million annually and $469 million during a 100-year storm event owing to the concentration of assets and population along its coastline. Fishing pressure, however, remains more intense in Ghana, threatening long term sustainability. Integrating carbon storage, fisheries pressure, and coastal protection within a unified analytical framework reveals key service trade-offs and synergies with direct implications for conservation investment priorities. Tanzania functions as a blue carbon stronghold requiring sustained protection, while Ghana represents a high-priority restoration frontier where integrated conservation and livelihood diversification can maximize ecosystem service co-benefits.