Antarctic marine viruses under scrutiny as researchers map unknowns of polar ecosystems

Antarctic marine viruses under scrutiny as researchers map unknowns of polar ecosystems
by Simon Mansfield
Sydney, Australia (SPX) Oct 16, 2025

Antarctic marine viruses have emerged as critical but poorly understood drivers of the Southern Ocean's ecological balance. A new review published in Ocean-Land-Atmosphere Research highlights both recent progress and significant gaps in understanding how these viruses shape biogeochemical processes under a changing climate.

Researchers from Australia and China synthesized current findings to identify where further work is needed. They emphasize that while DNA viruses have been studied for decades, RNA viruses - key regulators of microbial communities - remain largely unexplored.

"Antarctic marine viruses are central players in polar ecosystems, driving microbial mortality, nutrient regeneration, and biogeochemical cycling. Yet, our understanding is still incomplete - especially regarding RNA viruses and their role during phytoplankton blooms," said Chuan Zhai, researcher and first author of the study.

The team found that some RNA viruses appear to synchronize with phytoplankton bloom cycles, suggesting a vital role in sustaining food web dynamics and influencing the global carbon cycle. Viral infection and subsequent host-cell lysis release carbon, iron, and other nutrients into the surrounding waters, fueling microbial productivity.

The authors note that viruses can even support host survival in the Antarctic's extreme conditions through auxiliary metabolic genes (AMGs), which may enhance stress tolerance. However, determining the diversity, abundance, and ecological roles of these viruses requires advanced molecular tools.

Future work will likely focus on viral tagging and single-cell RNA sequencing to identify host-virus relationships. Particular attention will be directed toward the marginal ice zone - regions of intense biological and chemical variability that respond rapidly to seasonal and climatic shifts.

"The next step is to expand research on RNA viruses and virus-host interactions in underexplored regions of the Southern Ocean, using approaches such as large-scale metatranscriptomics and single-cell sequencing," said Dr. Fraser Kennedy, corresponding author of the study.

By coupling expanded viral surveys with predictive climate models, scientists hope to anticipate how warming, sea-ice retreat, and altered ocean chemistry may reshape viral dynamics and feedbacks in global carbon cycling.

Research Report:Antarctic Marine Viruses: A Review and Future Perspectives