Blue Carbon

Synonyms

Coastal carbon; Vegetated coastal carbon sinks

Definition

The term “blue carbon” refers to the proportion of “green” or biological carbon that is found in the oceans of the world (Nelleman et al., 2009). Three main types of coastal ecosystems contain the majority of this blue carbon. Mangroves are a type of tidal, forested wetland found in the tropics and subtropics. Tidal marshes are tidal wetlands dominated by emergent vegetation including grasses, sedges, and reeds. Seagrass beds or meadows are ecosystems along the coasts from the arctic to the tropics containing submerged aquatic vegetation, which resembles terrestrial grasslands. Because these three types of ecosystems store the majority of this carbon, “blue carbon” has become synonymous with coastal carbon. Altogether, mangroves, tidal marshes, and seagrass beds cover roughly 49 million hectares in area (Pendleton et al., 2012) and account for the burial of approximately 114–131 Tg (1 Tg = 1 × 10¹²g) C/year (Nelleman...