
08/23/2025
In a new study, researchers uncovered hundreds of giant viruses lurking in oceans across the globe, shining a light on mysterious players that shape life in our seas. Using advanced computer tools to sift through seawater samples, scientists from the University of Miami identified 230 completely new giant viruses never before seen. These aren’t your typical tiny viruses; they’re so large and genetically complex that they blur the line between life and non-life.
This discovery matters because these giant viruses often infect and kill phytoplankton—tiny plant-like organisms that produce much of Earth’s oxygen and sit at the base of marine food chains. By learning more about these viral predators, experts hope we can better understand and maybe even control harmful algal blooms, which pose health risks to humans and marine animals alike. Interestingly, some of these viruses carry genes for photosynthesis and carbon metabolism, hijacking their hosts’ energy-making machinery to fuel their own survival.
The study didn’t just catalog new viruses. It also found 569 new functional proteins, including several tied to photosynthesis, suggesting giant viruses may profoundly influence how carbon cycles through the ocean. The newly discovered viruses fit into two major families—Imitervirales and Algavirales—each using different strategies to infect marine life. As scientists continue to peer into these hidden ocean ecosystems, they believe we’ve only begun to scratch the surface of viral diversity, with many more surprises likely waiting in every drop of seawater.
Research Paper 📄
PMID: 40295861
PMCID: PMC12012013
DOI: 10.1038/s44298-025-00122-z