Professor Rene Boiteau

Rene Boiteau
Department of Chemistry
University of Minnesota

A Molecular Window into Iron Fertilization of the Southern Ocean

For decades, scientists have recognized that the addition of iron to surface waters stimulates algal growth in over a third of the world’s oceans, playing a pivotal role in regulating marine ecosystems and the global carbon cycle. However, predicting how climate change will affect these processes requires understanding iron’s chemical speciation and reactivity in the ocean, which is controlled by organic ligands that govern iron dissolution, transport, and biological uptake. Historically, studying these organic ligands has been limited by their low concentrations in a chemically complex mixture of dissolved organic matter. To overcome this challenge, the Boiteau research group has developed novel analytical approaches that combine advanced liquid chromatography with multi-modal mass spectrometry to separate, quantify, and identify organic ligands in seawater. These methods provide an unprecedented molecular-level window into the sources, composition, and fate of organically-bound metals in seawater. As part of the international GEOTRACES program, a coordinated international collaboration to quantify metal concentrations and fluxes across the ocean, we have applied these techniques to the South Pacific and Southern Ocean, the largest iron-limited ecosystem on Earth and a key driver of carbon dioxide sequestration. Results from these expeditions have identified specific regions along the Antarctic shelf that are major sources of iron binding ligands. Furthermore, we found that siderophores, strong chelators that facilitate biological iron uptake, are abundant throughout the water column, revealing that specific keystone microbial processes actively mediate iron dissolution and uptake across the Southern Ocean. This talk will highlight how these molecular discoveries provide mechanistic insights needed to improve models that predict how ocean productivity and carbon sequestration will change in the coming decades.

Rene Boiteau

Dr. Rene Boiteau received a bachelor’s degree in chemistry from Northwestern University in 2009. He earned an M.Phil. in Earth Sciences from the University of Cambridge, and a Ph.D. in chemical oceanography in 2016 from the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution. He conducted postdoctoral research in the Environmental Molecular Science Laboratory at the Pacific Northwest National Laboratory (2016–2018) as a Linus Pauling Fellow. He began his independent research career in the College of Earth, Ocean and Atmospheric Sciences at Oregon State University in 2018. In 2023, Boiteau moved to the Department of Chemistry at the University of Minnesota. His research group develops and applies new chemical analyses to understand how organic molecules control the cycling of essential nutrients and metals in the environment. His work has been recognized by numerous awards, including a Sloan Research Fellowship, and Simons Foundation Early Career Investigator award.

Hosted by Professor Lee Penn