Biogeochemistry of dissolved and particulate organic matter, combining optical spectroscopy, stable isotopes, and multivariate statistics to understand their sources and cycling. Coastal waters mostly but aquatic ecosystems generally. Recent work has incorporated the effects of land use and extreme weather events on organic matter biogeochemistry in estuaries. Other recent work seeks a biomarker for planktonic organic matter formation in the ocean. But also lakes in Greenland, so...