WHAT IS BLUE CARBON
Mangroves are evergreen shrub lands or forests that occur in tropical and subtropical shores and estuaries. They generally grow from mean sea level to the highest spring tide. Countries with the largest areas of mangroves include Australia, Bangladesh, Brazil, Cuba, India, Indonesia, Malaysia, Mexico, Mozambique, Myanmar, Nigeria and Papua New Guinea.
Tidal marshes are dominated by dense salt-tolerant plants such as succulent herbs and low shrubs, and grasses. They are found on soft sediments on sheltered coastlines, from the sub-arctic to the tropics, though most extensively in the temperate zones of Europe, North America, and Australia and in the higher latitudes of South-America and Africa.
The total global area of mangroves has been estimated as 8.2 million hectares (Hamilton and Casey, Global Ecology and Biogeography, 2016). Tidal salt marshes have been conservatively estimated to cover an area of 5.495 million hectares (Mcowen et al, Biodiversity Data Journal, 2017). The global area of seagrasses is less well defined. Rates of change of mangrove ecosystems have been assessed more frequently than tidal marshes and seagrasses. Further information concerning rates of change in these ecosystems will support refined carbon estimations for inclusion in national greenhouse gas inventories and inform future projects.