My research focusses on improving the quantitative understanding of the cycling of elements that are important to life in marine environments. The research is broad in scope and involves field and laboratory work that is typically integrated with modeling. The central theme is the assessment of the response of both ancient and modern environments to perturbations. Low oxygen marine environments in the present and past ocean are currently a key focus. Examples of areas where I and my group have performed seagoing research: Black Sea, Baltic Sea, Mediterreanean Sea, Arabian Sea, North Sea, Gulf of Mexico, Californian Margin. Research Fields: Marine Biogeochemistry, Paleoceanography, Biogeochemical ocean modeling, Reactive Transport Modeling, Hydrogeochemistry