Scientists uncover 230 new giant viruses in world’s oceans

Researchers at the University of Miami have discovered 230 new giant viruses in global ocean waters, shedding light on their hidden role in marine ecosystems and their potential impact on public health.

Tiny marine organisms such as algae, amoebas, and flagellates form the backbone of the ocean food chain—but viruses that infect them could significantly influence their growth, survival, and ecological functions. In some cases, these giant viruses may even trigger harmful algal blooms that threaten public health.

In a recent study published by researchers at the University of Miami’s Rosenstiel School of Marine, Atmospheric and Earth Science, scientists uncovered 230 previously unknown giant viruses by analyzing global ocean data with advanced computational tools.

The team also identified 530 new proteins encoded by these viruses, including nine linked to photosynthesis—indicating the viruses may interfere with the way their microscopic hosts harness sunlight for energy.

“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,” said Mohammad Moniruzzaman, a co-author of the study. “The novel functions found in giant viruses could have biotechnological potential, as some of these functions might represent novel enzymes.”

Understanding the diversity and function of giant viruses could also help predict and manage harmful algal blooms—events that pose growing risks to ecosystems and human health in places like Florida.

To identify these elusive viruses, researchers developed a new computational tool named BEREN. Unlike previous methods, BEREN provides an all-in-one solution for detecting and classifying giant viruses in DNA sequencing datasets.

Using BEREN, the team analyzed data from nine major ocean sampling projects. After extracting the viral genomes, scientists used public gene databases to determine the biological roles of viral genes and compared them to known virus genomes to identify new functions.

Lead author Benjamin Minch, a doctoral student at the Rosenstiel School, noted that many of the viruses carry genes involved in critical cell functions such as carbon metabolism and photosynthesis—functions usually exclusive to living cells. This discovery suggests that giant viruses may significantly alter the metabolism of their hosts and influence vital marine chemical cycles.

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