University of Tennessee Uncovers Viral Impact on Ocean Oxygen Levels
A groundbreaking study led by researchers from the University of Tennessee, Knoxville, and the University of Maryland has revealed a fascinating connection between viral infections and ocean oxygen levels. The interdisciplinary research, published in Nature Communications, showcases how viral activity in blue-green algae can significantly impact the ocean's ecosystem.
The findings challenge the traditional view of viruses as solely harmful agents, highlighting their role in stimulating growth and production. Steven Wilhelm, a renowned microbiologist and one of the study's senior authors, emphasizes, "Viruses are integral to the microbial world, and their activity can be just as crucial for growth as it is for causing disease."
The research team, including four faculty members and three students from the University of Tennessee, collaborated with institutions like the Georgia Institute of Technology and the Technion Institute of Technology in Israel. They embarked on a National Science Foundation research cruise to the Sargasso Sea, where they conducted around-the-clock RNA sequencing surveys of microbial life.
The study focused on the cyanobacteria Prochlorococcus, which, when infected by viruses, releases nutrients that fuel the growth of other microbes. This process contributes to the formation of a rich oxygen band in the water, extending tens of meters below the surface for several months annually. Wilhelm explains, "The viral activity is a significant driver of this oxygenated ribbon, which is a remarkable phenomenon in the ocean."
The research establishes a direct link between the viral shunt, a concept first introduced by Wilhelm and Curtis Suttle in 1999, and the microbial loop in the ocean's food web. By analyzing cellular and viral activity data, the team identified the viral infection's impact on the entire ecosystem. Biology Professor Joshua S. Weitz from the University of Maryland notes, "Viral infections enhance the recycling of carbon and nutrients, leading to increased productivity and a deeper understanding of the ocean's subsurface dynamics."
The study's lead author, Naomi Gilbert, along with other UT authors, including Alison Buchan and Gary LeCleir, contributed to the RNA sequencing and additional analyses. The research was funded by the National Science Foundation and supported by the Simons Foundation. Wilhelm and Weitz will further explore these findings in an upcoming article in The Conversation.
The publication, titled 'Seasonal enhancement of the viral shunt catalyzes a subsurface oxygen maximum in the Sargasso Sea,' was published in Nature Communications on December 6, 2025. This research not only expands our understanding of viral interactions in the ocean but also opens up new avenues for exploring the complex relationships between viruses, microbes, and the ocean's overall health.
