Paytan Biogeochemisty Lab

photos of sunsets

Delphine Defforey

Phosphorus biogeochemistry, marine geochemistry, sedimentary geochemistry

Earth and Planetary Sciences
University of California Santa Cruz

Delphine Defforey


I grew up near Geneva, Switzerland. After years of fog and rain, I decided it was about time I moved to a sunnier place, so I moved to Austin, Texas. There, I attended the University of Texas at Austin and pursued a Bachelor of Science in biology, with an emphasis on marine and freshwater biology. During the course of my studies, I had the opportunity to study marine botany in Puerto Rico, and to volunteer as surveyor for a nonprofit organization in Seychelles. The different courses I took, as well as the research projects I worked on, led me to develop an interest in seagrasses, mangroves and coral reefs, especially how anthropogenic activities disrupt those ecosystems. I then became interested in how human activity influences nutrient cycles, and this is what led me to study biogeochemistry here at UCSC.

Project Description

My work focuses on phosphorus (P) cycling in open ocean sediments and the interactions between deep sedimentary subseafloor microorganisms and sedimentary P. Some of the tools I use for my research include sediment sequential extractions, solution 31P nuclear magnetic resonance spectroscopy, stable oxygen isotopes in phosphate as a tracer for P cycling, metagenomics and enzymatic assays.

My project will be funded in part by C-DEBI (Center for Dark Energy Biosphere Investigations). For more info on C-DEBI click

Page last updated October 8, 2015