Efficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation

The fate of old, recalcitrant dissolved organic carbon in oceans is unclear. Field samples show that loss during circulation in hydrothermal vents can account for the 40-million-year lifetime of recalcitrant dissolved organic carbon in oceans. Oceanic dissolved organic carbon (DOC) is an important carbon pool, similar in magnitude to atmospheric CO2, but the fate of its oldest forms is not well understood1,2. Hot hydrothermal circulation may...