In July of 2024, oxygen was discovered on the ocean floor where no light nor plants were present. After various tests, it seems as though the different minerals located on the floor of the Clarion-Clipperton Zone are acting as a large collection of batteries that are being charged by the electric currents flowing along the ocean floor (Lingam et al., 2024). This immediately sparked numerous tests with the purpose of discovering if life can grow and exist with dark oxygen production (DOP). This research is incredibly important because it may indicate certain conditions in which life may exist on a water or ice planet.
Through research done at Cornell University, we have learned a few things about this phenomenon. The oxygen was collected using a benthic chamber, a chamber which allows on-site measurements of the exchange rates of substances between the ocean floor and the water in and around the chamber (Sweetman et al., 2024) (Figure 1).
Based on the oxygen measurements, it seems that the potential reason for oxygen to be present without photosynthesis on the ocean floor is the concept of electrophy, which is the process of separating water into its elements (hydrogen and oxygen) through the use of electricity. For the circumstances on the ocean floor where the phenomenon was discovered, it seems there are numerous electric currents going across the ocean floor which could trigger this electrophy. They then charge the elements on the ocean floor (lithium, cobalt, copper, etc.) to essentially create natural batteries (Lingam et al., 2024). The oxygen created from this phenomenon has since been dubbed, dark oxygen due to its creation from a lack of sunlight (Colarossi, 2024).
In terms of what creatures could exist in a domain created from DOP, we know that metazoans (animals) may be able to exist in these conditions if they are in the millimeters of sizes; however if an organism is able to have “internal circulation systems for the distribution of oxygen” (Lingam et al., 2024), then the upper size boundary of these organisms could instead be between approximately 0.1 cm to approximately 10 cm.
There are still many factors to consider during the early stages of this discovery, but if this system proves consistent, the possibility of life on fully water or ice planets increases dramatically. There could be entire systems of creatures living on ocean planets that are entirely unknown to us, but the research of this topic has become threatened by seabed mining companies.
Since there’s a plethora of elements that are used in making batteries on the ocean floor, many seabed mining companies are pushing for the ability to strip mine in these areas and profit off of the abundance of resources.
A quote by the BBC with Professor Murray Roberts, a marine biologist from the University of Edinburgh, states, “There’s already overwhelming evidence that strip mining deep-sea nodule fields will destroy ecosystems we barely understand,” (Gill, 2024). These strip mining endeavors could severely hinder the research being done about DOP by disrupting the habitat in which it is occurring. To prevent this over 800 marine biologists from 44 countries have signed a petition in hopes of halting the strip mining process and allowing more discoveries to occur in this field without interruption (Gill, 2024).
There is still a lot to discover about this process and its impact on the world around us, but the potential of this discovery has incredible implications for our understanding of the creation of life not just on Earth but on other planets as well. We can only look forward to more discoveries like this from the depths of our mysterious oceans.
References
Lingam, M., Balbi A., & Tiwari M. (2024, August 13). Dwellers in the Deep: Biological Consequences of Dark Oxygen. Cornell University. https://arxiv.org/pdf/2408.06841
Gill, V. (2024, July 22). Dark oxygen made by deep sea “batteries.” BBC News. https://www.bbc.com/news/articles/c728ven2v9eo
Colarossi, J. (2024, August 15). Oxygen produced in the deep sea raises questions about extraterrestrial life on other planets. Boston University. https://www.bu.edu/articles/2024/deep-sea-oxygen-raises-questions-about-extraterrestrial-life/#:~:text=This%20phenomenon%20creates%20enough%20energy,oxygen%20made%20with%20no%20sunlight
NOAA Office of Ocean Exploration and Research (2019). [Deep sea metal lumps of oxides of iron and manganese]. Southeastern U.S. Deep-sea Exploration.
Sweetman, A.K., Smith, A.J., de Jonge, D.S.W. et al. Evidence of dark oxygen production at the abyssal seafloor. Nat. Geosci. 17, 737–739 (2024). https://doi.org/10.1038/s41561-024-01480-8
Carvalho, V. [Benthic Chamber]. Max Planck Institute for Marine Microbiology.
