What is "blue carbon"?
According to the Intergovernmental Oceanographic Commission (IOC), one of the most promising new ideas to reduce atmospheric CO2 and limit global climate change is to do so by conserving mangroves, seagrasses and salt marsh grasses. Such coastal vegetation, dubbed “blue carbon”, sequesters carbon far more effectively (up to 100 times faster) and more permanently than terrestrial forests. Carbon is stored in peat below coastal vegetation habitats as they accrete vertically. Because the sediment beneath these habitats is typically anoxic, organic carbon is not broken down and released by microbes. Coastal vegetation also continues to sequester carbon for thousands of years in contrast to forest, where soils can become carbon-saturated relatively quickly. Therefore, carbon offsets based on the protection and restoration of coastal vegetation could be far more cost effective than current approaches focused on trees. Furthermore, there would be enormous ad-on benefits to fisheries, tourism and in limiting coastal erosion from the conservation of blue carbon.
You can see all the organic rich sediment that gets accumulated in the mangrove roots as the forest accretes vertically. This makes mangrove forests highly effective at capturing and storing carbon emitted into the atmosphere by humans. However, when mangrove forests are destroyed for development, vast amounts of carbon is released, intensifying global climate change.
Source: United Nations Information Center Manila.