New Discoveries of Giant Viruses Transform Understanding of Marine Ecosystems

In a groundbreaking study published in June 2025, scientists from the Rosenstiel School of Marine, Atmospheric and Earth Science at the University of Miami unveiled the discovery of 230 novel giant viruses in the world's oceans. This research significantly enhances our understanding of the roles these viruses play in marine ecosystems, particularly concerning photosynthesis and harmful algal blooms, which pose public health risks globally.

The research team utilized advanced bioinformatics techniques and high-performance computing to analyze vast marine metagenomic datasets. Their findings, detailed in the journal *Nature npj Viruses*, revealed the presence of new giant virus genomes, including the characterization of 530 new functional proteins, nine of which are linked to photosynthesis. This suggests that giant viruses may influence their hosts' photosynthetic processes, particularly in single-celled organisms known as protists, which include algae, amoebae, and flagellates—the foundational components of ocean food webs.

Dr. Mohammad Moniruzzaman, an assistant professor in the Department of Marine Biology and Ecology and a co-author of the study, emphasized the implications of these discoveries. "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," he stated. Harmful algal blooms can lead to toxic conditions in coastal waters, impacting marine life and human health alike.

The research also highlights the potential biotechnological applications of the novel functions identified within these giant viruses. "The novel functions found in giant viruses could represent new enzymes with biotechnological potential," said Dr. Moniruzzaman.

Until recent advancements in bioinformatics, giant viruses remained largely unexamined due to the limitations of existing detection methods. The team created an innovative tool named BEREN (Bioinformatic tool for Eukaryotic virus Recovery from Environmental metagenomes), which facilitates the identification of giant virus genomes within extensive public DNA sequencing datasets. Benjamin Minch, the lead author and a doctoral student at the Rosenstiel School, noted, "This study allowed us to create a framework to improve existing tools for detecting novel viruses that could aid in our ability to monitor pollution and pathogens in our waterways."

The researchers' analysis involved downloading DNA sequencing data from nine major global ocean sampling projects, enabling them to recover and annotate giant virus genomes effectively. The BEREN program stands as a significant advancement in the field, simplifying the identification and classification of giant viruses in sequencing datasets. The tool is publicly available for researchers and can be accessed at https://gitlab.com/benminch1/BEREN.

This advancement in understanding giant viruses not only sheds light on marine biology but also has significant implications for environmental monitoring and public health management. The ongoing exploration of the ocean's viral diversity promises to unveil further complexities of marine ecosystems and their interconnections with terrestrial environments. As research continues, scientists anticipate uncovering additional roles of these giant viruses, which may be crucial in shaping the future of ecological conservation efforts and public health strategies.