Blue carbon is carbon that is taken up by coastal and marine ecosystems through photosynthesis and stored on the seafloor and in the deep ocean. It was introduced in the 2009 United Nations Environment Programme (UNEP) report ’Blue Carbon’ and has attracted worldwide attention as a new option for carbon sink measures. The main carbon sinks for Blue Carbon are seagrass meadows and macroalgal beds, salt marshes and tidal flats, and mangrove forests, which are called "Blue Carbon ecosystems".
Source: Based on materials from the Japan Blue Economy Association
Seagrasses, such as eelgrass, are marine flowering plants that bloom in the sea, reproduce by seeds, and spend their entire lives in the sea. They are found in relatively shallow areas and do not grow deep in the sea floor. e.g., eelgrass, sea duck, etc.
Algae living in the sea. They reproduce by spores. The root of macroalgae (seaweed) don't exist to absorb nutrients; they exist to adhere to rocks. e.g., kelp, wakame seaweed, etc.
An area of sandy or muddy shallow water in the intertidal zone that dry up at low tide and submerges below the sea surface at high tide are called tidal flats. They are formed when sediments carried by rivers and coastal currents accumulate on beaches and estuaries. Wetlands with thick reeds and other vegetation that develop close to land in tidal flats are called salt marshes.
Trees that inhabit brackish water areas where river water and seawater mix, such as estuaries in the tropics and subtropics. In Japan, they are distributed along the coasts further south than Kagoshima Prefecture.
Blue carbon ecosystems have a variety of values in addition to their function as CO₂ sinks. For example, they provide many benefits to our daily lives, such as water purification, revitalization of fishery resources, and educational and recreational opportunities. Promoting activities to conserve blue carbon ecosystems will not only prevent global warming, but will also foster an ocean rich in biodiversity, which in turn will lead to a richer life for all of us.