Uncovering Viral Roles in Oxygen Minimum Zones

Posted on July 18, 2025  •  2 minutes  • 355 words

Warmer ocean temperatures are leading to expanding oxygen loss within Earth’s oceans, negatively impacting global fisheries. Microbial processes exacerbate ocean deoxygenation and in low oxygen conditions facilitate the production of gases, including nitrous oxide and methane, that can have feedbacks on atmospheric and ocean chemistry. Despite the significant role of microbes, little is known about controls on microbial processes within oxygen-depleted marine waters, including the impact of viral infection. Such information is critical to accurately forecast the impact of ocean deoxygenation.

The Blue Bioinformatics Lab is pursuing research to understand the impacts of phages (viruses that infect bacteria and archaea) and RNA viruses within these systems.

Expeditions

Brown and team have visited three of the largest marine oxygen minimum zones on the planet, the ETNP, the ETSP and the Bay of Bengal in three consecutive years to amass a multi-dimensional collection of samples that will be used for high throughput sequencing of DNA and RNA from multiple size fractions to uncover the diversity of viruses within these systems and pair them with host organisms.

AT5008: MicroPro Expedition to the Eastern Tropical North Pacific OMZ

The first OMZ expedition took place in 2023 aboard the R/V Atlantis, departing out of Puntarenas, Costa Rica, and visiting the Eastern Tropical North Pacific Oxygen Minimum Zone off of the western coast of Mexico. Brown conducted virus sample collection in order to enhance sampling efforts of collaborator and chief scientist Maria Pachiadaki. Brown documented her travels to the ETNP in several 2023 blog posts , and her time at sea was featered in Bigelow’s Transect Magazine .

FKt_240415: Microbes in Oxygen Minimum Zones

The second expedition took place in 2024 aboard Schmidt Ocean’s R/V Falkor(too). Brown and team were part of the microbes in oxygen minimum zones Cruise, and collected a rich and comprehensive collection of samples for viral and bacterial enumeration and characterization.

Bay of Bengal

After learning the ropes in the ETSP, Montana State Graduate student Annabelle Adams-Beyea is at sea in the the Bay of Bengal on the R/V Thompson collecting the third set of viral samples under the guidance of collaborator and Chief Scientist Maria Pachiadaki.