Nodules were first called “a battery in a rock” by The Metals Company (TMC) to emphasize the importance of deep-sea minerals for sustainable energy production. These polymetallic nodules contain key battery metals like copper, nickel, cobalt, and manganese.
However, recent research published in Nature Geoscience proposes a fascinating new theory. An international team of scientists, led by professor Andrew Sweetman from the Scottish Association for Marine Science, suggest that these nodules might actually act as natural batteries by producing oxygen through a process called electrolysis. This discovery challenges the conventional notion that oxygen is only generated through photosynthesis.
Professor Sweetman and his team conducted multiple research expeditions in the Clarion-Clipperton Zone (CCZ) in the Pacific Ocean in 2021 and 2022. By using benthic chambers to create controlled environments on the seafloor, they observed a significant accumulation of oxygen in the presence of nodules, indicating excess oxygen production. The researchers even found that a voltage similar to that of a household AA battery is needed to split seawater into hydrogen and oxygen molecules, hinting at the nodules’ potential role in oxygen generation.
While this breakthrough opens up new possibilities for oxygen production in the deep sea, Professor Sweetman remains cautious. He believes that further investigation is necessary before considering large-scale nodule mining operations, emphasizing the importance of environmentally friendly practices.
On the other hand, The Metals Company (TMC) expressed skepticism about the findings, citing concerns about the study’s validity and methodology. TMC argues that the data collected may not accurately represent the seafloor environment and highlights conflicting studies that suggest net oxygen consumption rather than production. They also point out that the research paper had been rejected by other journals before being accepted in Nature Geoscience.
The controversy surrounding the dark oxygen hypothesis underscores the complexity of deep-sea mineral exploration in the CCZ. As various stakeholders await regulations from the International Seabed Authority (ISA) that could permit future mining activities in the region, the debate over the true nature of nodules continues.
In conclusion, the ongoing research on polymetallic nodules and their potential role as natural batteries highlights the need for further scientific inquiry and responsible resource management in deep-sea environments. As we navigate the delicate balance between technological advancement and environmental preservation, it is crucial to consider all perspectives and evidence before making decisions that could impact our planet’s delicate ecosystems.
