Deep-sea pressure squeezes nutrients from marine snow, study finds
7 reported
A new study from the University of Southern Denmark reports that extreme deep-sea pressure forces valuable nutrients out of sinking organic particles, providing an unexpected food source for ocean microbes. The research, published in Science Advances, suggests that deep ocean microbes are not living in a nutrient-starved environment as previously assumed. The findings could change how scientists understand deep-ocean ecosystems and Earth’s carbon cycle. The study found that tiny sinking particles known as marine snow release dissolved carbon and nitrogen as they descend, with pressure acting like a giant juicer. The researchers estimate that sinking marine snow can lose up to 50% of its original carbon and between 58% and 63% of its original nitrogen during descent. This leakage may mean less carbon is permanently stored in seafloor sediments than previously believed, with much remaining suspended in deep waters for hundreds or thousands of years. The team plans to search for molecular fingerprints of this process in the Arctic Ocean during a future expedition aboard the German research vessel Polarstern.
What’s reported
The study was conducted by researchers at the University of Southern Denmark and published in Science Advances.
Marine snow particles release dissolved carbon and nitrogen when subjected to hydrostatic pressure at depths of about 2 to 6 kilometers.
The pressure forces dissolved organic matter out of particles, which microbes can use immediately.
Sinking marine snow can lose as much as 50% of its original carbon and between 58% and 63% of its original nitrogen during descent.
In laboratory experiments, bacterial abundance increased 30-fold within two days after nutrient release.
The same leakage pattern was observed across multiple species of diatoms.
The next phase of research will involve an expedition to the Arctic Ocean aboard the research vessel Polarstern.
Key figures
Peter Stief, biologist and Associate Professor, University of Southern Denmark (first author of the study)
Jutta Niggemann, Margot Bligh, Hagen Buck-Wiese, Urban Wünsch, Michael Steinke, Jan-Hendrik Hehemann, Ronnie N. Glud (co-authors)
Sources: ScienceDaily
