230 new giant viruses with unusual powers discovered in Earth’s oceans

Vast New World of Giant Viruses Uncovered in Earth’s Oceans (Representative Image: Canva)

It turns out the sea still hides many secrets—some too small to see. Scientists have now discovered hundreds of giant viruses lurking beneath the waves, offering a new window into how oceans function and how marine life survives.

Hundreds of unknown giruses found across global oceans
A new study has identified 230 previously unknown giant viruses, also called "giruses", using advanced computer software to analyse ocean and waterway samples. Researchers found these large viruses by scanning genetic material with a tool called BEREN, which helped them map 230 complete and 398 partial genomes.

These viruses were not just hiding—they may also hold influence. The study, published under the title “Expansion of the Genomic and Functional Diversity of Global Ocean Giant Viruses”, revealed 530 new functional proteins. Nine of those are linked to photosynthesis, hinting that these giruses might manipulate this essential process during infection.

Such a discovery changes the way scientists think about the food chain in ocean ecosystems. Giant viruses can infect tiny marine life such as algae and amoebae, which are key to ocean health and the planet’s carbon cycle.

Giruses may change how we understand ocean ecosystems
The research revealed two main families of giruses—Algavirales and Imitervirales. Algavirales are known to target algae, while Imitervirales have a more flexible genetic structure, allowing them to adapt to different hosts. Their large genetic codes may give them an edge in controlling and altering host functions more powerfully than standard viruses.

These ocean giants have turned up in cold waters too. The Baltic Sea and Antarctic waters were hotspots, with 108 and 65 discoveries respectively. Additional clusters were found in the Arctic, South Pacific, and North Atlantic, suggesting cold regions are rich with unexplored viral life.

Researchers highlight role of viruses in marine health
Mohammad Moniruzzaman, one of the authors, said these giruses might play a big role in controlling algae blooms, which can harm humans and marine life. “By understanding how these viruses behave, we might be able to predict or manage algal blooms,” he said.

Benjamin Minch, another contributor, said the research offers tools that can help track viruses and pollution. The study’s framework could improve how we monitor water quality and detect pathogens across marine environments.

The findings also point to a future where some of these viral proteins may be used in biotechnology. Scientists now hope to learn more about their enzymes, how they affect marine food chains, and whether they can be used in science and medicine.

This work adds an important layer to our understanding of ocean life, suggesting that even the smallest players can have the biggest impact.