Microbiology doctoral candidate Jason Olavesen sailed to the Southern Ocean with an international team investigating microscopic organisms that drive global carbon cycles.
Microbiology research took a University of Tennessee, Knoxville, student on a voyage in the Southern Ocean for nearly seven weeks in early 2026.
Jason Olavesen, a third-year PhD student in UT’s Department of Microbiology, joined an international research team aboard the British Antarctic Survey’s flagship, the RRS Sir David Attenborough.
Led by chief scientist Alessandro Tagliabue, a professor at the University of Liverpool, the IronMan project focuses on understanding the influence of micronutrients such as iron and manganese on the ecosystems in the Southern Ocean and developing more reliable climate model projections. The Southern Ocean shapes global conditions because of its significant role in absorbing carbon and heat.
The expedition included an interdisciplinary team of more than 40 researchers with expertise ranging from physical oceanography and aerosols to zooplankton ecology and photophysiology.
“A typical day aboard ship involved collecting water from multiple depths using Niskin bottles and the vessel’s underway pump systems, followed by hours of careful filtration and preservation for downstream DNA and RNA sequencing and analysis,” Olavesen said. “These samples will help reveal how marine microbial communities and photosynthetic phytoplankton respond to changing light and nutrient conditions in the Southern Ocean.”
Some samples were brought to the Knoxville campus for another UT graduate student, Sarah Lott, to analyze by RNA sequencing and by metabolomics.
Olavesen said the voyage was the most memorable experience yet as a member of the Wilhelm Lab, where his training has included bench-based microbiology and bioinformatics in addition to field research.
“This was a massive opportunity for Jason to work with a team of oceanographic all-stars, for our lab, and for the department,” said Distinguished Professor Steven Wilhelm, the Kenneth and Blaire Mossman Professor in UT’s microbiology department. “The USA is presently without a large-class icebreaker that can carry out this type of research in this region.”
UT, ORNL Collaboration
Olavesen also was one of 11 recipients of the 2025–26 GATE (Graduate Advancement, Training, and Education) fellowships from the UT-Oak Ridge Innovation Institute, for his research on how nitrogen sources such as agricultural fertilizer affect the growth of harmful cyanobacteria. He has been using an LI-COR trace gas analyzer in the lab of ORNL Staff Scientist Dave Weston to study carbon and energy acquisition in the organisms.
The research trip to Antarctica also highlights the strong scientific connection between the Weston and Wilhelm groups, both of which are interested in how molecular photosynthetic machinery is regulated in dynamic environments, Olavesen said. “By examining the genetic and transcriptional signatures of Southern Ocean microbes, this work will improve understanding of ocean productivity, strengthen climate models, and inform future applications in water-resource management and biotechnology,” he said.