Deep Ocean Microbes Primed for Climate Change Fight

Nitrosopumilus maritimus may adapt well to warmer, nutrient-poor waters, helping reshape ocean-nutrient distribution.

Published on Mar. 10, 2026

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A new study shows that the microbe Nitrosopumilus maritimus, which accounts for 30% of marine microbial plankton, may be able to adapt well to the warming and nutrient-poor conditions of the deep ocean caused by climate change. Researchers predict these ammonia-oxidizing archaea will play an important role in reshaping ocean-nutrient distribution as the climate changes.

Why it matters

The oceans depend on these microbes to drive the chemical reactions that support marine life. By altering the forms of nitrogen available in seawater, they control the growth of microbial plankton - the base of the marine food chain - and help sustain marine biodiversity. As the deep ocean warms, understanding how these key microbes respond is crucial for predicting the future of ocean ecosystems.

The details

The study, led by University of Illinois Urbana-Champaign microbiology professor Wei Qin and University of Southern California global change biology professor David Hutchins, used controlled experiments to expose a pure culture of Nitrosopumilus maritimus to varying temperatures and iron concentrations. They found that increasing temperature under iron-limited conditions reduced the microbes' iron requirements and increased their physiological iron-use efficiency, demonstrating their ability to acclimate to higher temperatures and decreased iron availability.

  • This summer, Qin and Hutchins will serve as co-chief scientists aboard the research vessel Sikuliaq for a research expedition from Seattle to the Gulf of Alaska and then down to the subtropical gyre, stopping in Honolulu, Hawaii.
  • The study's findings are published in the Proceedings of the National Academy of Sciences.

The players

Wei Qin

University of Illinois Urbana-Champaign microbiology professor who co-led the study.

David Hutchins

University of Southern California global change biology professor who co-led the study.

Nitrosopumilus maritimus

An ammonia-oxidizing archaea that accounts for approximately 30% of the marine microbial plankton population and plays a key role in the oceans' nutrient cycling.

Alessandro Tagliabue

University of Liverpool researcher who contributed global ocean biogeochemical modeling to the study.

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What they’re saying

“Ocean-warming effects may extend to depths of 1,000 meters or more. We used to think that deeper waters were mostly insulated from surface warming, but now it is becoming clear that deep-sea warming can change how these abundant archaea use iron - a metal they depend on heavily - potentially affecting trace metal availability in the deep ocean.”

— Wei Qin, University of Illinois Urbana-Champaign microbiology professor (Mirage News)

What’s next

Qin and Hutchins will work to validate the study's experimental findings in a real-world setting during their upcoming research expedition aboard the R/V Sikuliaq.

The takeaway

This research suggests that deep-sea microbes like Nitrosopumilus maritimus may be able to adapt to the warming and nutrient-poor conditions of the changing climate, potentially playing a key role in maintaining the chemical and biological balance of the oceans in the face of climate change.