A recent groundbreaking study led by researchers from the University of Tennessee, Knoxville, alongside the University of Maryland, has unveiled a fascinating connection between viral infections in oceanic blue-green algae and enhanced oxygen levels in marine ecosystems. This discovery highlights the complex and vital role that viruses play in our environment.
As Steven Wilhelm, a prominent microbiology professor at UT and a senior author of the research, points out, "We inhabit a microbial planet, and viruses are integral to its processes." He emphasizes that the influence of viruses is not solely negative; they also promote growth and productivity within marine life, rather than just causing illness and disease.
Wilhelm had the opportunity to lead a National Science Foundation research expedition to the Sargasso Sea, which culminated in this significant paper published in Nature Communications (https://www.nature.com/articles/s41467-025-67002-1). The research team comprised four faculty members and three students from UT, in collaboration with experts from institutions such as Georgia Tech, Ohio State University, Technion Institute of Technology in Israel, and the University of Maryland.
During their voyage on the research vessel, the Atlantic Explorer, in October 2019, the scientists conducted continuous RNA sequencing to survey the microbiological landscape at the Bermuda Atlantic Time-series Study site (https://bios.asu.edu/bats), a long-term project that has been gathering a wealth of physical, biological, and chemical data about the ocean for nearly 40 years.
The results from this study indicate that when cyanobacteria, specifically Prochlorococcus, are infected by viruses, they release nutrients that stimulate further microbial growth. This process plays a key role in maintaining elevated oxygen levels in the water, extending tens of meters beneath the ocean's surface. "The findings suggest that this ribbon of oxygen-rich water, residing approximately 50 meters below the surface for several months each year, is significantly influenced by viral activity," Wilhelm explains.
Moreover, the research establishes a direct correlation between two fundamental oceanographic concepts: the 'viral shunt'—a term first introduced by Wilhelm and Curtis Suttle from the University of British Columbia back in 1999—and the microbial loop, which is essential for understanding the ocean's food web dynamics.
Joshua S. Weitz, a biology professor at the University of Maryland, elaborates on the methodology, stating, "By examining extensive data on both cellular and viral behaviors across day-night cycles, including the status and prevalence of viruses infecting cyanobacteria, we can pinpoint the impact of viral infections at a systemic level." He adds that viral infections seem to enhance the recycling of carbon and nutrients by various microbes, thereby fueling productivity and shedding new light on historical patterns linking viral activity to ecosystem health beneath the ocean's surface.
The extensive RNA sequencing and subsequent analyses were carried out at UT, with Naomi Gilbert (PhD '22) serving as the lead author. Other contributors from UT include microbiology professors Alison Buchan and Gary LeCleir, along with Jennifer DeBruyn from the Department of Biosystems Engineering and Soil Science, and former UT students Helena Pound (PhD '21) and Shelby Cagle ('21).
This collaborative effort, spearheaded by Wilhelm and Weitz, was supported by a National Science Foundation Collaborative Research grant, as well as backing from the Simons Foundation and other entities. For those interested in delving deeper into this exciting research, Wilhelm and Weitz will be sharing further insights in The Conversation (https://theconversation.com/institutions/university-of-tennessee-688).
/Public Release. This information originates from the respective organization/author(s) and may be time-sensitive. It has been edited for clarity, style, and length by Mirage.News, which does not take institutional stances. All views and conclusions expressed here are solely those of the authors. Read the full piece here (https://www.miragenews.com/ut-study-reveals-viral-impact-on-ocean-oxygen-1600748/).
