230 New Giant Viruses Have Been Found In Most of the Planet's Oceans

Yahoo

16-06-2025

Scientists at the Rosenstiel School of Marine, Atmospheric, and Earth Science looking at water from the world's oceans discovered something odd: 230 types of giant viruses that were previously unknown. 'Giant' is a relative term here, since we're dealing with viruses, and viruses aren't known to be all that big. But in virus sizes, these new ones are positively enormous.
A giant virus (yes, it's a scientific term) can be as large as two microns. For context, if you were to pull out a piece of your hair, it would likely be in the 70 micron range. But for a virus, two microns is Godzilla-sized. And while there are almost certainly many more viruses floating around out there that we don't know about just yet, the scientists who found these new ones are pretty excited about their discovery.
It'd be easy to think that finding a bunch of new viruses in the ocean is bad, but it's actually a pretty good thing. Right now many oceans are in the middle of a wide-ranging algal bloom that's full of domoic acid. That's bad for things like seals and sea lions, because domoic acid can kill. But by studying these new giant viruses, researchers are learning a whole lot about how they can deal with things like harmful algal blooms.
'By better understanding the diversity and role of giant viruses in the ocean and how they interact with algae and other ocean microbes, we can predict and possibly manage harmful algal blooms, which are human health hazards in Florida as well as all over the world,' explained Mohammad Moniruzzaman, one of the two authors of the new study. 'The novel functions found in giant viruses could have biotechnological potential, as some of these functions might represent novel enzymes.'
Giant viruses don't generally infect humans or animals, instead preferring things like algae or amoebas, so we don't have anything to worry about unless something out of a zombie movie happens to them. They are, however, very important in the grand scheme of things.
'We discovered that giant viruses possess genes involved in cellular functions such as carbon metabolism and photosynthesis – traditionally found only in cellular organisms, said Benjamin Minch, the lead author of the study and a doctoral student in the Department of Marine Biology and Ecology at the Rosenstiel School. 'This suggests that giant viruses play an outsized role in manipulating their host's metabolism during infection and influencing marine biogeochemistry.'
Since things like phytoplankton act as a bit of a foundational building block for the ecosystems in the ocean, understanding how these giant viruses interact with them could have sweeping impacts.
'Overall, our work provides new insights into the diversity and functional potential of [giant viruses] in the world's oceans through our addition of 230 genomes with an expanded set of photosynthesis proteins as well as many other metabolic genes,' the paper finished. 'We hope that these new genomes along with protein annotations, will be useful in the expansion of insights into [giant viruses] from further metagenomic datasets across all aquatic ecosystems.'