Just like salt marshes and mangroves, seagrasses are ecologically important habitats in coastal ecosystems and are also important carbon storages. Seagrasses absorb CO2 and other forms of inorganic carbon from water and air and produce organic biomass, i.e. new plant components, by means of photosynthesis. Dead parts of the seagrass plant can be buried into the deeper, oxygen-poor layers of the tidal flat sediment by current-induced sediment reallocation or burrowing activity of animals. Bacteria that are responsible for decomposing the organic material and would thus release the carbon again can hardly become active there due to the lack of oxygen. The carbon incorporated in the plant parts can thus be stored in the seabed for many centuries. In addition to this internal source, seagrasses also act as filters for sediment and organic material, which is transported into the seagrass bed from outside. Sediment and organic material may originate from deeper areas of the sea and then be transported towards the coast, or may be directly from nearby coastal vegetation. Above a seagrass bed, these components are literally fished out of the seawater near the bottom as if with a comb. In this way, new layers of sediment and organic material are continuously deposited in the seagrass meadow, leading to a further accumulation of organic material that can be stored in the seabed for up to thousands of years.