UT Study Unveils Viral Role in Ocean Oxygen Production
A groundbreaking interdisciplinary study led by the University of Tennessee, Knoxville, and the University of Maryland has revealed a fascinating insight into the ocean's ecosystem. The research demonstrates that viral infections of blue-green algae in the ocean can significantly boost productivity and contribute to higher oxygen levels in the water. This discovery challenges our understanding of microbial life and its impact on the environment.
"Our planet is a microbial world, and viruses play a crucial role in this intricate process," explains Steven Wilhelm, the Kenneth and Blaire Mossman Professor at UT's Department of Microbiology and a senior author of the study. "Their activities can be as vital for growth and production as they are for causing sickness and disease."
The study, published in Nature Communications, was conducted during a National Science Foundation research cruise to the Sargasso Sea. The team, led by Wilhelm, included four UT faculty members, three students, and collaborators from the Georgia Institute of Technology, Ohio State University, Technion Institute of Technology in Israel, and the University of Maryland. They embarked on the Atlantic Explorer in October 2019, conducting around-the-clock RNA sequencing surveys of the microbiology at the Bermuda Atlantic Time-series Study, a long-standing project that has been collecting ocean data for nearly four decades.
The research focused on the cyanobacteria Prochlorococcus and its viral infections. The study found that these infections release nutrients that fuel microbial growth, resulting in higher oxygen levels in the water, particularly tens of meters below the surface. Wilhelm highlights that this oxygen-rich band, which forms for several months each year, is at least partly driven by viral activity.
The study establishes a direct link between two fundamental oceanographic concepts: the viral shunt, first described by Wilhelm and Curtis Suttle in 1999, and the microbial loop in the ocean's food web. By analyzing large-scale data on cellular and viral activity, including infection status and viral abundances, the researchers identified the viral infections' impact on the entire system. Biology Professor Joshua S. Weitz from the University of Maryland emphasized that viral infections enhance carbon and nutrient recycling, driving productivity and shedding new light on historical trends indicating a connection between viral activity and ecosystem functioning below the surface.
The lead author of the paper is Naomi Gilbert, who completed her PhD in 2022. Other UT authors, including microbiology Professor Alison Buchan and Assistant Professor Gary LeCleir, contributed to the study. The research was funded by a National Science Foundation Collaborative Research grant and supported by the Simons Foundation and other organizations. Wilhelm and Weitz will continue to share their findings through The Conversation, inviting further discussion and exploration of this intriguing viral phenomenon in the ocean.
