The proposed work involves a characterization of nitrogen cycling in the low oxygen region of the Eastern Pacific Ocean using genomics, proteomics, and stable isotope tracer experiments. A 28-day cruise on a UNOLS research vessel from X to Y is proposed in Year 2. For this project, PI Alyson Santoro will assist in cruise planning, field sampling, data collection, data analysis, and publication. She will mentor a postdoctoral researcher and graduate student involved in the project and supervise the laboratory technician. She will have final responsibility for all publications resulting from this work. The postdoctoral researcher, under the direction of PI Santoro, will contribute to bioinformatic analysis of the metagenomic data and contribute to all publications resulting from that work. A laboratory technician will be responsible for ordering supplies, assisting with shipping, and participating in the research cruise. A graduate student will be responsible for conducting at sea ¹⁵N tracer incubation experiments, d¹⁵N_NO3 sample preparation and analysis, and data interpretation.