UT Study Unveils Viral Role in Ocean Oxygenation
A groundbreaking interdisciplinary study led by the University of Tennessee, Knoxville, and the University of Maryland has revealed a fascinating aspect of ocean life. Researchers found that viral infections in blue-green algae significantly impact ocean ecosystems, leading to increased oxygen levels in the water.
"Our planet is a microbial ecosystem, and viruses play a crucial role in this intricate process," explained Steven Wilhelm, a renowned microbiologist at UT and a senior author of the study. "Their activities can be as beneficial as they are detrimental." Wilhelm was the chief scientist on a National Science Foundation cruise to the Sargasso Sea, where the research was conducted.
The team, including four UT faculty members, three students, and collaborators from Georgia Tech, Ohio State University, Technion Institute of Technology in Israel, and the University of Maryland, embarked on a journey aboard the research vessel Atlantic Explorer in October 2019. They spent days and nights conducting RNA sequencing surveys of the microbiology in the Bermuda Atlantic Time-series Study, a long-standing project that has been monitoring ocean data for decades.
The study focused on the cyanobacteria Prochlorococcus, which, when infected by viruses, releases nutrients that stimulate microbial growth. This process results in a notable increase in oxygen levels in the water, forming a wide band of oxygenated water tens of meters below the surface. Wilhelm emphasized that this oxygen-rich zone, which persists for several months annually, is at least partly driven by viral activity.
The research establishes a direct connection 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 vast datasets on cellular and viral activity over day-night cycles, the team identified the viral infection's impact on the entire ecosystem.
"Our findings suggest that viral infections enhance the recycling of carbon and nutrients, boosting productivity and shedding new light on historical trends," said Joshua S. Weitz, a biology professor at the University of Maryland. "This discovery highlights the intricate relationship between viral activity and ecosystem functioning beneath the ocean's surface."
The study's lead author, Naomi Gilbert, a recent PhD graduate, and other UT authors, including Alison Buchan and Gary LeCleir, contributed significantly to the research. The study was funded by the National Science Foundation and supported by the Simons Foundation. Wilhelm and Weitz will share more insights on this research in The Conversation, inviting public engagement and discussion.
This groundbreaking study not only deepens our understanding of ocean ecosystems but also emphasizes the importance of viruses in maintaining the delicate balance of marine life.
