Scientists discovered that polymetallic nodules on the Pacific Ocean floor (approx. 4,000 m deep) produce “dark oxygen” without sunlight or photosynthesis. These metal-rich rocks, located in the Clarion-Clipperton Zone, act as natural, low-voltage batteries that split seawater into oxygen and hydrogen, a process called seawater electrolysis.
This finding challenges the assumption that oxygen is only produced by plants and algae. The study was published in the journal Nature Geoscience.
Key Details About Discovery
- Location: The discovery was made in the Clarion-Clipperton Zone (CCZ), a vast, deep-sea area in the Pacific Ocean between Hawaii and Mexico.
- Mechanism: Researchers found that polymetallic nodules (rocks containing cobalt, nickel, and manganese) generate electric potentials of up to 95V, which is sufficient to split water into hydrogen and oxygen, similar to a battery.
Significance:
- This suggests that oxygen production is not exclusively dependent on photosynthesis, redefining understanding of deep-sea life and oxygen origins.
- It reveals a previously unknown biological process where microbes produce oxygen in complete darkness, likely through radiolytic splitting of water by natural radiation.
- This challenges the long-held assumption that oxygen production is strictly tied to sunlight-driven photosynthesis.
- Such findings expand our understanding of deep-sea ecosystems and the potential for life in extreme environments, with implications for astrobiology and Earth’s biogeochemical cycles.
Environmental Concern:
- The polymetallic nodules responsible for this “dark oxygen” are also targets for deep-sea mining. There is concern that mining activities could destroy this previously unknown oxygen source.