Chemical oceanography encompasses the study of the chemical components of the oceans, their reactions, and their pathways of transformation. We study both organic and inorganic compounds, particulate and dissolved material, and the ocean sediments. The pathways that compounds follow affect the global cycling of elements such as carbon and nitrogen, and are often intimately related to biological activity. We undertake our research in environments such as cold seeps and saline lakes, salt marshes, and deep ocean sediments. We combine field observations, laboratory experiments, and computer models to understand factors affecting chemical compositions and how they vary in time and space.