Macrophytes, such as mangroves, salt marshes and sea grasses, constitute an important component of coastal domain (Kathiresan and Bingham, 2001; Kathiresan, 2007), but their role in carbon budget is neglected from accounts of the global ocean carbon cycle for the main reason that the marine vegetation occupies only less than 2% of the oceanic surface (Duarte and Cebrian, 1996). Moreover, the coastal macrophytes are being cleared and converted globally at alarming rates. For instance, the annual rate of loss in global mangroves was disturbingly high, 0.66%, during the years 2000–2005 (FAO, 2007).