Dr. Mark Schmidt is a member of the Marine Biogeochemistry Division of the German research institute GEOMAR and Associate Professor at University Kiel (“Privatdozent”). He started his scientific career in the 90s as an environmental/physical chemist (PhD in atmospheric chemistry), and then changed to earth sciences (habilitation in geosciences in 2006). Over the last decades his research interest has been using stable isotopes to reconstruct a wide range of (bio)geochemical processes in earth sciences. He specialized in mineral formation at cold and hot marine vent areas. Moreover, he investigated trace gas-formation, ‑degradation, and -transport processes in most of the oceans worldwide.