Linking Marine Microbial Activity and Climate Feedbacks
Marine oxygen-depleted zones account for just 0.1% of the ocean’s volume. Yet, they have a large impact on the ocean’s health, its ability to capture carbon, and its greenhouse gas emissions. In oxygen-depleted zones, most multicellular life, such as fish, cannot survive. However, these waters are far from dead: microbes “breathe” nitrogen instead of oxygen, leading to a significant loss of bioavailable nitrogen—a nutrient essential for marine life, including the algae that support much of the ocean's food web. Importantly, some of this nitrogen loss occurs as emission of nitrous oxide, a highly potent greenhouse gas that contributes to global warming. With ongoing climate change, these low-oxygen zones are expanding, threatening marine ecosystems and affecting the ocean’s feedbacks on climate.
Despite their critical role, the microbes driving these nitrogen transformations and the environmental factors that regulate microbial activity in oxygen-depleted ocean zones remain poorly understood. “Studying microbes in oxygen-depleted systems is challenging due to inevitable oxygen contamination during the recovery of samples and subsequent laboratory experiments” says CeMESS Senior Scientist Katharina Kitzinger. “This limits our ability to predict how microbes in oxygen-depleted waters will respond to the changing climate.”
The ERC Synergy Grant RECLESS will address this gap by quantifying the key controls on microbial activity in oxygen-depleted zones. The scientists will use new oxygen-sensing technology that allows the measurement of oxygen concentrations at unprecedented resolution and sensitivity. Additionally, the scientists have developed incubation systems that enable experiments on microbial communities from oxygen-depleted waters without exposing them to oxygen. “By identifying key microbial players, studying their responses to environmental conditions, and building the first global microbial ecosystem model for oxygen-depleted marine regions, RECLESS will transform our understanding of nitrogen cycling in the ocean” Kitzinger adds.
The groundbreaking project brings together four leading scientists, each contributing unique expertise. Katharina Kitzinger (University of Vienna) specializes in microbial physiology, visualization, and activity measurements at the single-cell level. On a larger scale, Laura Bristow (University of Gothenburg) addresses nitrogen transformations by entire microbial communities in oxygen-depleted zones, while Bo Thamdrup (University of Southern Denmark) contributes expertise in innovative oxygen-sensing and oxygen-free incubation technologies. Emily Zakem (Carnegie Institution for Science) brings advanced microbial ecosystem modeling to the table. Together, they aim to predict how ocean deoxygenation will affect nitrogen cycling, greenhouse gas emissions, and the global carbon cycle, setting new standards in marine research.
About Katharina Kitzinger
Katharina Kitzinger’s research focuses on the microbiology and biogeochemistry of nitrogen cycling, with a particular emphasis on single-cell measurements that link the identity of specific microbes to their activities within complex ecosystems. She earned her PhD in 2019 as a joint degree from the University of Vienna and the Max Planck Institute for Marine Microbiology (Bremen, Germany), where she received several awards for her work. Following a three-year postdoctoral position at the Max Planck Institute, funded by the Reimar Lüst Fellowship of the Max Planck Society, she returned to Vienna. Since 2022, Kitzinger has been a senior scientist at the Centre for Microbiology and Environmental Systems Science (CeMESS) at the University of Vienna and serves as a key researcher in the FWF Cluster of Excellence “MicroPlanet – Microbiomes Drive Planetary Health.”
Links
- Press Release University of Vienna (German only)
