Assistant Professor Julie Granger is one of four CLAS professors to earn an NSF CAREER award

Assistant Professor of Marine Sciences Julie Granger has been awarded $791,496 over five years for her project, “The biological nitrogen isotope systematics of ammonium consumption and production.”

Granger’s work seeks to create a basis through which researchers can better understand the oceanic nitrogen cycle. Isotopic data can be useful to interpreting nitrogen cycle processes in the ocean that are difficult to measure directly. Granger’s research will investigate the processes behind isotope fractionation, or relative abundance, of ammonium during biological processes. It will investigate whether low concentrations of ammonium in the surface ocean affect isotope fractionation when the ammonium is recycled, and whether there is a trophic isotope effect associated with ammonium recycling by plankton.

The research will create a baseline from which researchers can interpret recycled nitrogen dynamics from ammonium isotope datasets, and will significantly enhance our ability to understand the ocean’s fundamental chemistry and its vulnerability to human impacts.

Granger also plans to integrate science with community-engaged learning by developing an undergraduate field and laboratory course requiring students to present their research to stakeholders in the community. A manual created for this course will be disseminated in open-access forums for teachers to develop similar courses.