The Cooperative Institute for Climate, Ocean, and Ecosystem Studies

Hi, my name is Erin Novobilsky. I am a rising senior at Marist University studying Environmental Science and Biochemistry. During my time in the CICOES summer program, I worked alongside my mentor Dr. Travis Mellet with Dr. Randie Bundy. My project was focused on changes to iron bioavailability across a natural biogeochemical gradient in the northern Equatorial Pacific.

Iron (Fe) is a necessary micronutrient that limits productivity in large portions of the surface ocean, which has an impact on the global cycling of carbon. In the ocean, it is typically found complexed with organic molecules. These are known as organic ligands and they have a variety of strengths and sources. Some are produced by bacteria when concentrations of bioavailable Fe are low, and are known as siderophores. We focused on seawater samples from two Gradients cruises that crossed areas with different nutrient limitations to see how iron chemistry and the microbial community changed.

The first part of my project included setting up competition experiments against a ligand with a known concentration and binding strength to measure the concentration and strength of the organic compounds in the seawater samples. This is called competitive ligand exchange adsorptive cathodic stripping voltammetry and the titrations performed were interpreted using a different software. I also gained experience throughout the summer working in a clean lab, which has the goal of limiting contamination of samples. The concentrations of iron in the samples is very small compared to everywhere else, so it is important to keep them clean.

I also had exposure measuring dissolved Fe in seawater. To do this, salts were removed from seawater samples using a seaFAST system and put in a solution that the concentration of dissolved Fe can be measured on a Thermo Element Inductively Coupled Plasma Mass Spectrometer (ICP-MS). This data was coupled with siderophore concentrations that were previously collected and flow cytometry data for analysis.

This program was an incredible opportunity to explore a research area in oceanography that I had no previous exposure to at my home institution. It opened my eyes to the different paths I could go down for graduate school and I thoroughly enjoyed every aspect of the research process. I am excited that I will be able to use all of the skills I learned both in and out of the lab in the future. The University of Washington in Seattle was an amazing place to spend the summer, and I am so thankful to CICOES for the valuable experience and my mentors for their constant guidance and support throughout the summer.

Project Introduction

Research Poster