The carbon captured by living organisms in oceans is stored in the form of sediments from mangroves, salt marshes and seagrasses. Benefiting from the excellent conditions available to support plant growth, vegetated coastal habitats rank amongst the most productive habitats in the world, comparable in production to the most productive agricultural crops. Blue carbon sinks are strongly autotrophic, which means that these ecosystems fix CO2 as organic matter photosyntheticaly in excess of the CO2 respired back by biota, thus removing CO2 from the atmosphere. Some of this excess carbon is exported and subsidies adjacent ecosystems, including open ocean and beach ecosystems. The remaining excess production of mangrove forests, salt-marshes and seagrass meadows is buried in the sediments, where it can remain stored over millenary time scales, thereby representing a strong natural carbon sink.
From collection: Blue Carbon-The Role of Healthy Oceans in Binding Carbon