Carbon fluxes and stocks in a carbonate-rich chenier plain

•We examined the carbon pools and fluxes in a carbonate-rich coastal ecosystem.•The C sink of the chenier plain is comparable to that of organic-rich salt marshes.•The chenier plain had a net CO2 evasion during the entire soil formation process.•Plant growth and succession enhance organic carbon accumulation in a chenier plain.•Inorganic carbon storage should be considered in blue carbon inventories.