Dr. Jon Martin is Professor at the Department of Geological Sciences, University of Florida. His research focuses on how water flowing through conduits exchanges with water of the high-porosity matrix rocks. He has been active in developing tools to measure and predict fluxes of nutrients through carbonate karst watersheds and is currently studying the effects on metal diagenesis and organic carbon remineralization as high organic carbon content water reverses into springs during flooding. Most of his research on karst aquifers has been on the Floridan aquifer, but has also worked in the Bahamas and the Yucatan Peninsula.