Saint Helena Virtual Forum
Dark Oxygen
Oxygen Made By Rocks at the Bottom of the Ocean?​
Available for viewing on October 23, 2024
In a surprising twist to a controversial topic presented this June here on the Forum, scientists have since reported “dark oxygen”...oxygen that is created in the dark on the abyssal ocean seafloor by the same “polymetallic nodules” discussed in that earlier Forum. This alternative oxygen source to photosynthesis could support the variety of life seen at these great depths. This research was published in the journal Nature Geoscience, 22 July 2024.
This new study, led by Dr. Andrew Sweetman of the Seafloor Ecology and Biogeochemistry research group at the Scottish Association for Marine Science of the UK focused on the same polymetallic nodules found on the ocean seabed as presented in a previous forum. These nodules, which grow at an incredibly slow rate of 1-3 millimeters per million years, are rich in minerals crucial to the production of new clean energy infra-structure. The study was funded by The Metals Company's subsidiary Nauru Ocean Resources Inc. (NORI) which has campaigned to convince the world of deep sea mining’s potential and viability.
But the results of the research NORI itself bankrolled are likely to make things more difficult for them. In response to the Nature Geoscience publication, The Metals Company, which seeks to mine these nodules, disputes the research and the existence of dark oxygen, claiming that the research which they funded through their subsidary is flawed. Led by Gerard Barron, Chairman & CEO of The Metals Company (who was interviewed this last June on the Forum), they have since issued a rebuttal, accusing Sweetman’s team of omitting critical data, misrepresenting research, and conducting contaminated experiments.
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(Given the environmental implications of this new information on the mining of the abbyssal ocean floor, the Saint Helena Forum will interview Dr. Sweetman, the lead researcher about his work on October 23, 2024.
Earlier interviews on this topic can be viewed on the Past Forums page on our website and on the Forum's YouTube channel.)
Dr. Andrew Sweetman
Dr. Andrew K. Sweetman is the lead researcher of the paper. Sweetman holds a PhD in deep-sea ecology from the Max Planck Institute for Marine Microbiology (Germany). Andrew is an expert on seafloor biodiversity and ecology and has a strong focus on the impact of anthropogenic stressors on shallow and deep-sea benthic ecosystems.
In response to The Metals Company’s critique, Sweetman's team maintained that its research was transparent. Sweetman’s team stated, “We don’t have anything to hide.”
“My co-authors and I stand fully behind the findings in this research paper, which has been published by a highly respected academic journal following a stringent and lengthy peer review process. “We were the worst critics of this paper for a long time.
For eight years I discarded the data showing oxygen production, thinking my sensors were faulty. Once we realised something may be going on, we tried to disprove it, but in the end we simply couldn’t. “We would welcome future peer-reviewed studies that further investigate this phenomenon. “Following the publication of this paper, I have been approached by other researchers with similar data-sets also showing evidence of dark oxygen production that they discarded thinking equipment was faulty.”
James is a subsea vehicle developer, pilot, and former Head of the Office of Resources and Environmental Monitoring for the International Seabed Authority in Kingston, Jamaica. His background includes international ocean policy development, undersea systems design and manufacturing, oceanographic research, marine operations, training, and business management. His experience in all facets of subsea development, research, and operations has provided him with a unique perspective on the marine environment and the stewardship of this natural resource.
Topic Background
In our race to cut greenhouse gas emissions and address climate change, there is tremendous demand for critical minerals like lithium, cobalt and graphite which are essential components of EV batteries, wind turbines, and solar panels, as well as other low-carbon energy technologies. While we currently mine these materials on land, demand pressures have some looking to tap the sea floor for its metal ores much of which lie in potato-sized polymetallic nodules .
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A conservative estimate is that 21.1 billion dry tons of polymetallic nodules lie in the Clarion-Clipperton Zone manganese nodule field, the largest in area and tonnage of the known global nodule fields. The Zone spans 4.5 million square kilometers (1.7 million square miles) between Hawaii and Mexico, an abyssal plain as wide as the continental United States and punctuated by seamounts. Lying atop the muddy bottom or embedded just beneath it are trillions of potato-size polymetallic nodules.The nodules sit on the sediment surface across abyssal plains in a region in a zone spanning 5,000 kilometers across the central Pacific Ocean, at depths of ~4,000 - 5,500 meters (12,000 - 18,000 feet) undisturbed in waters of unusual clarity.
Based on that estimate, tonnages of many critical metals in these nodules are greater than those found in global terrestrial reserves
Some nations are already applying to the ISA for permits to explore deep-sea mining where the bulk of the ocean’s critical minerals are found. The ISA now has until 2025 to finalize regulations that will dictate whether and in what manner countries could pursue deep-sea mining in international waters.
The Clarion-Clipperton Zone
