In 2013, a groundbreaking discovery was made by ocean scientist Andrew Sweetman and his team during an expedition to the Clarion-Clipperton Zone, a remote region in the Pacific Ocean. They found that oxygen was being produced at depths of 13,100 feet, where no light penetrates, challenging the traditional understanding that oxygen production requires photosynthesis. This phenomenon, known as “dark” oxygen production, occurs independently of photosynthesis and is linked to polymetallic nodules found on the seafloor.
These nodules, rich in metals like cobalt, nickel, copper, lithium, and manganese, are in high demand for use in green technologies such as electric car batteries and solar panels. The nodules form over millions of years through chemical processes that cause metals to precipitate out of seawater and accumulate around organic material.
Research conducted by Sweetman’s team revealed that the nodules generate electric currents in saltwater, leading to the production of oxygen through seawater electrolysis. This discovery suggests that these nodules act like natural batteries, generating electricity that splits water molecules to produce oxygen.
The discovery of dark oxygen production has significant implications for deep-sea mining, which targets these polymetallic nodules for their valuable metals. Environmentalists and scientists have raised concerns about the potential impact of mining on deep-sea ecosystems, as the nodules play a crucial role in supporting deep-sea life. Disrupting the nodules could have far-reaching effects, potentially creating “dead zones” where marine life cannot recover.
The potential for irreversible harm to deep-sea environments highlights the importance of sustainable mining practices to protect these newly discovered oxygen sources. There is a growing call among scientists and environmentalists for a moratorium on deep-sea mining until more is understood about its ecological impact.
