Rising sea temperatures caused by ocean heatwaves and climate change are reaching deep into the ocean, raising concerns about disruption to the ocean’s fragile chemical and biological systems. But new research shows that important marine microorganisms are Nitrosopumilus Maritimemay already have adapted to a warm, nutrient-poor environment. Scientists believe that these adaptive microorganisms, which rely heavily on iron and perform ammonia oxidation, could have a major impact on how nutrients are distributed across the ocean as the climate continues to change.
The research results are Proceedings of the National Academy of Sciences.
Microorganisms that drive ocean nutrient cycles
Nitrosopumilus Maritime Closely related microorganisms make up about 30% of marine microplankton. Many scientists believe they are essential to ocean chemistry because they promote reactions that support marine ecosystems. These archaea oxidize ammonia, a process that plays a central role in the ocean’s nitrogen cycle.
These microorganisms control microbial plankton growth by converting nitrogen into various chemical forms in seawater. These tiny organisms form the basis of the marine food chain, meaning that the activity of ammonia-oxidizing archaea ultimately helps maintain marine biodiversity.
Deep sea warming may change the amount of iron used
“The effects of ocean warming could reach depths of more than 1,000 meters,” said Wei Qing, a professor of microbiology at the University of Illinois at Urbana-Champaign. “While we previously thought the deep ocean was largely protected from surface warming, it is now becoming clear that deep-sea warming may change the way these abundant archaea use iron, a metal on which they rely heavily, and may impact the availability of trace metals in the deep ocean.”
Experiment reveals microorganisms use iron more efficiently in warmer water
The research team, led by Hata and David Hutchins, a professor of global change biology at the University of Southern California, conducted carefully controlled experiments to avoid trace metal contamination. they exposed pure cultures Nitrosopumilus Maritime Compatible with different temperatures and different iron levels.
Their results showed that as temperature increases under iron-limiting conditions, the microorganisms require less iron and utilize it more efficiently. This finding indicates that organisms can adjust their metabolism to cope with both high temperatures and reduced iron availability.
Modeling suggests future bigger role in ocean chemistry
“We combined these findings with global ocean biogeochemical modeling by Alessandro Tagliabue at the University of Liverpool,” Qin said. “These results suggest that deep-sea archaeal communities may maintain or enhance their role in supporting nitrogen cycling and primary production across vast iron-limited regions in a warming climate.”
Upcoming ocean expeditions to test findings
Later this summer, Chin and Hutchins will serve as co-principal investigators on the research vessel. Sikuliak. The expedition will travel from Seattle to the Gulf of Alaska, then continue its subtropical circulation, stopping in Honolulu, Hawaii.
The voyage will include an additional 20 researchers investigating the ocean’s natural archaeal populations. Their goal is to confirm their experimental results in real-world conditions and better understand how temperature changes and metal availability interact to shape microbial activity in the deep ocean.
Mr. Hata is also affiliated with the Carl R. Wuth Institute for Genome Biology.
The National Science Foundation, the Simmons Foundation, the National Natural Science Foundation of China, the University of Illinois at Urbana-Champaign, and the University of Oklahoma supported this research.
