US researchers identify 230 new viruses with surprising effect on ocean health

Tiny ocean organisms like algae, amoebas, and flagellates are key to the marine food chain, and giant viruses that infect them can affect how they grow and survive. In some cases, these viruses may also lead to public health issues, such as harmful algal blooms.

According to Interesting Engineering, in the quest to unravel the varying kind of viruses found inside our planet’s large water-bodies, scientists at University of Miami’s Rosenstiel School of Marine, Atmospheric and Earth Science have uncovered 230 new giant viruses using advanced computing tools and ocean data.

Researchers also identified 530 new proteins within these viruses, including nine linked to photosynthesis—suggesting the viruses may interfere with how their hosts convert sunlight into energy.

According to Mohammad Moniruzzaman, co-author of the study and assistant professor in the university’s Department of Marine Biology and Ecology, gaining a better understanding of the diversity and role of giant viruses in the ocean—and how they interact with algae and other microbes—could help predict and potentially manage harmful algal blooms, which pose risks to human health in Florida and around the world.

“Giant viruses are often the main cause of death for many phytoplankton, which serve as the base of the food web supporting ocean ecosystems and food sources. The novel functions found in giant viruses could have biotechnological potential, as some of these functions might represent novel enzymes,” explained Moniruzzaman in a press release on University of Miami’s website.

Detecting giant viruses has proved to be a challenge so far because current computer methods had limitations. To overcome this, the research team created a new tool called BEREN—a program which offers a simple, all-in-one tool for identifying and classifying giant viruses in sequencing datasets.

To conduct their study, researchers gathered DNA sequencing data from nine major ocean sampling projects spanning the globe. Using BEREN they extracted giant virus genomes from this data.

The scientists then analyzed the genomes using public gene function databases to identify the roles and activities encoded by these viruses. Following this, the results were compared to known giant virus genomes to uncover previously unknown functions and gain deeper insight into their diversity.

Benjamin Minch, lead author of the study and a doctoral student at the Rosenstiel School, observed that giant viruses carry genes linked to important cellular functions like carbon metabolism and photosynthesis—processes usually found only in living cells. This finding suggests that these viruses have a significant role in altering their host’s metabolism during infection and may impact key marine chemical cycles.