My research focuses on the application of stable isotopes and other approaches for understanding the biogeochemical cycling of carbon and nitrogen in a variety of ecosystems. Current research projects include: (1) understanding novel nitrogen cycling pathways in Lake Vida, Antarctica, (2) the impact of the Deepwater Horizon oil spill on hypoxia in the northern Gulf of Mexico, (3) application of the isotopomers of nitrous oxide to evaluate the origins of this greenhouse gas and (4) instrument development to enable real-time and in situ stable isotope measurements.