Copper, cobalt and black oxygen, the superpowers of polymetallic nodules

The exploration of the deep never ceases to amaze and bring new discoveries! 

The latest is the discovery of a 'black oxygen' produced by polymetallic nodules in the abyssal plains of the Pacific Ocean.

Scientists have discovered that polymetallic nodules, mineral concretions containing rare metals such as nickel and cobalt, can act like electric batteries and, by electrolysis of water, separate molecules into hydrogen and oxygen.

This chemical reaction is triggered by the grouping of nodules, which produces an electrical voltage that enables electrolysis to take place.

This discovery is the result of a study carried out by researchers from the Scottish Association for Marine Science (SAMS), who took samples of sediment and nodules from the abyssal plain of the Clarion-Clipperton geological fracture zone, at a depth of more than 4,000 m.

The work was funded by The Metals Company and UK Seabed Resources. These companies want to exploit the deep seabed and extract these nodules, whose metal composition (manganese, nickel, cobalt) would be used to produce batteries for electric vehicles, photovoltaic panels and mobile phones.

The aim of this campaign was to assess the impact of mining prospecting on this particular ecosystem, where exploration regularly yields new and unique species.

Professor Andrew Sweetman, who led the study, now says that more research is needed into the production of "black oxygen" during studies into deep-sea mineral extraction.

The discovery of oxygen production in an environment without light and therefore without photosynthesis raises questions about "how life on Earth came to be", reports Nicholas Owens, Director of SAMS.

"The conventional view is that oxygen was first produced around three billion years ago by ancient microbes called cyanobacteria and there was a gradual development of complex life thereafter.  ", says Nicholas Owens, " The potential that there was an alternative source requires us to have a radical rethink".

This discovery comes against a backdrop of discussions and negotiations within the IAMF on the future of the deep seabed and the potential exploitation of its mineral resources , where those in favour of a moratorium or even a ban on exploitation are pitted against those in favour of exploiting the abyss.

Sources : Le Monde, SAMS