On July 22, 2024, the scientific journal Nature Geoscience published a paper by Sweetman et al. titled “Evidence of dark oxygen production at the abyssal seafloor”. The paper provides the first findings that identify the potential for polymetallic nodules to produce oxygen on the seafloor of abyssal plains (named “dark oxygen”). The paper has garnered interest from everyone connected to the deep sea mining industry, including deep ocean scientists, companies, and NGOs. Significant media attention followed as 115 NGOs cited it as a reason for a moratorium or ban on deep sea mining, and some mining companies wrote responses questioning the validity of the research (TMC, Adepth). Tomasz Trzpil wrote a post on the amount of oxygen generated is fairly small.

Unsurprisingly, the response from the scientific community has been the same as for other new discoveries: we need additional research to replicate results and learn more about this phenomenon and what it means for the ecosystem.

It is also interesting to note that this study was paid for, in part, by The Metals Company (TMC), and was carried out in their license area in the Clarion Clipperton Zone. Since the study was released, TMC wrote an article questioning the validity of the study. This makes it clear that scientists contracted by mining companies are carrying out truly independent work, without requirement to walk the company line. Anyone questioning the integrity of scientific work being paid for by companies should take note of this example. A significant portion of deep sea research is funded by mining contractors as part of their required exploration work plans, and the amount of data being generated is immense. Unfortunately, this also means that if a moratorium were to come into effect, exploration programs generating this data may be shuttered or slowed due to lost investment. 

The Impossible Metals team supports the need for additional research on this fascinating topic. Our goal has always been to deliver technology to harvest polymetallic nodules from the seafloor in the most responsible manner possible, and research into dark oxygen will inform our development and planning. 

Image courtesy of NOAA Ocean Exploration, 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts.