New research in coastal Japan quantifies how macroalgae and seagrasses contribute to long term carbon storage through the release of recalcitrant dissolved organic carbon. The study finds that seagrasses have a higher mean recalcitrant fraction at 25 percent compared to 14 percent for macroalgae over a 100 year timescale. These findings suggest that the export of dissolved organic carbon is a major carbon storage process, comparable to the burial of particulate organic carbon in deep sea sediments. This data helps refine blue carbon accounting for coastal ecosystems.
