University of Tennessee Uncovers Viral Impact on Ocean Oxygen Levels
A groundbreaking study led by the University of Tennessee, Knoxville, and the University of Maryland has revealed a fascinating connection between viral infections and ocean health. The research, published in Nature Communications, demonstrates that viral activity in blue-green algae can significantly boost the ocean's productivity and oxygen levels.
"Our planet is a microbial ecosystem, and viruses play a crucial role in this intricate balance," explains Steven Wilhelm, a microbiology professor at UT and a senior author of the study. "Their impact goes beyond disease; they can stimulate growth and production, too."
The study was conducted during a National Science Foundation research cruise to the Sargasso Sea, where a team of scientists, including UT faculty and students, collaborated with researchers from other institutions. They spent days and nights aboard the Atlantic Explorer, conducting continuous RNA sequencing to study the microbiology of the Bermuda Atlantic Time-series Study site.
The findings were eye-opening. The team discovered that viral infections in a type of cyanobacteria called Prochlorococcus release nutrients that fuel the growth of other microorganisms, resulting in higher oxygen concentrations in the water column.
"This oxygen-rich band, visible for several months each year, is at least partly driven by viral activity," Wilhelm notes. "It's a remarkable natural phenomenon."
The research also established a direct link between viral infections and the microbial loop, a fundamental component of the ocean's food web. By analyzing cellular and viral activity data, the scientists identified how viral infections enhance the recycling of carbon and nutrients, driving productivity and ecosystem functioning.
"Our findings shed new light on the relationship between viral activity and ocean health," says Joshua S. Weitz, a biology professor at the University of Maryland. "Viral infections seem to play a key role in the ocean's ability to sustain life."
The study's lead author, Naomi Gilbert, along with other UT authors, including Alison Buchan and Gary LeCleir, contributed to the research. The project was funded by the National Science Foundation and supported by the Simons Foundation.
The team will share more insights in an upcoming The Conversation article, inviting readers to explore the fascinating world of viral oceanography.
Nature Communications (https://www.nature.com/articles/s41467-025-67002-1)
Journal: Nature Communications
Article Title: Seasonal enhancement of the viral shunt catalyzes a subsurface oxygen maximum in the Sargasso Sea
Publication Date: 6-Dec-2025
