Deep Sea Viral "Dances In The Dark" Discovered As Ohio State Researchers Uncover Unexpected Nocturnal Activity In The Sargasso Sea

Ohio State researchers find 90% of cyclical marine viruses peak at night, targeting heterotrophic microbes and providing new data for global ocean models.

By: AXL Media

Published: Mar 31, 2026, 11:15 AM EDT

Source: Information for this report was sourced from Ohio State University

Nocturnal Dynamics in the Sargasso Marine Microbiome

Research conducted by The Ohio State University has uncovered a complex temporal framework governing viral interactions in the Sargasso Sea. In a study published in PLOS Biology, microbiologists found that nearly all viruses exhibiting cyclical changes in abundance reached their peak activity during the night. This finding surprised the research team, as they initially hypothesized that microbial activity would accelerate during daylight hours to coincide with photosynthesis. Instead, the data suggests that the "dances in the dark" are a primary driver of the marine ecosystem’s viral economy.

Targeting Heterotrophic Hosts Over Photosynthetic Microbes

The study clarified that the viruses most active at night were not infecting the bacteria responsible for photosynthesis, despite those being common viral targets. Rather, these nocturnal viruses focus on heterotrophic microbes, which must consume other organic matter because they cannot produce their own food. First author Alfonso Carrillo noted that this discovery reveals a previously unknown level of complexity in how viruses interact with marine bacteria, opening new doors for understanding the ecological services provided by the Atlantic Ocean.

High Frequency Sampling at Varying Ocean Depths

To capture these rapid shifts, the research team utilized the Bermuda Atlantic Time Series to collect water samples every four hours at the surface and every twelve hours in the deep chlorophyll maximum (DCM). Over a 112-hour period, they analyzed more than 48,000 virus species. Of these, approximately 3,100 demonstrated "diel" behavior, meaning their abundance fluctuated in predictable 24-hour cycles. The variation between surface levels and the DCM, which differs in light, temperature, and oxygen, allowed researchers to map how viral behavior changes across different environmental frameworks.