People: Astrobiology Graduate Students

Clara Fuchsman
Oceanography

Before arriving at the University of Washington, I studied biochemistry at Swarthmore College. I continue to combine biology and chemistry for my PhD in oceanography. I joined the astrobiology program later in my graduate career because I like how interdisciplinary is valued and fostered here, and I enjoy putting my research in a bigger perspective.

I study the nitrogen cycle in the Black Sea by examining both isotope geochemistry with Jim Murray to try to decipher in situ rates and microbiology with Jim Staley to determine who is catalyzing each process. The Black Sea is a permanently anoxic basin. Understanding nitrogen cycling in the Black Sea may shed light on nitrogen cycling in the ocean over a billion years ago (in the mid-Proterozoic) when the deep ocean is thought to have been anoxic. We are interested in all stages of the N cycle, but are particularly interested in the controls for denitrification versus the anammox process because denitrification produces N2O, a greenhouse gas, as an intermediate, while anammox does not. Due to the potential copper limitation in the final step of denitrification, N2O may have been a more important greenhouse gas during the mid-Proterozoic than in the present day (Buick, 2007).