Marine scientists who made headlines final yr with their discovery that deep sea nodules might be producing “darkish oxygen” are embarking on a three-year analysis challenge to clarify their findings.

Amid swirling controversy over their analysis, challenge lead Andrew Sweetman on the Scottish Affiliation for Marine Science says he hopes the brand new scheme will “present as soon as and for all” that metallic lumps of rock are sources of deep sea oxygen and begin to clarify how the method is working. “We all know that it’s occurring, and what we have to now do is present it once more, after which actually begin getting on the mechanism,” he says.

Sweetman had spent greater than a decade learning life on the ocean flooring earlier than his shock discovery made headlines in July final yr, and confounded the analysis neighborhood. Beforehand, it was thought that oxygen manufacturing relied on the presence of crops, algae or cyanobacteria to carry out photosynthesis, powered by daylight.

However Sweetman’s staff discovered rising oxygen ranges on nodule-rich areas of sea flooring, 1000’s of metres beneath the ocean floor the place no mild can penetrate and no crops develop. The researchers urged that the nodules might be performing as “geobatteries”, producing an electrical present that splits water molecules into hydrogen and “darkish” oxygen, produced naturally with out photosynthesis.

Sweetman discovered himself on the centre of a media storm. Life modified in a single day, he says – he even will get stopped on the road by individuals wanting {a photograph} with him. “It’s been very surreal,” he says.

However the discovery additionally introduced challenges. The analysis has attracted criticism from some scientists and deep-sea mining corporations, who plan to mine the nodules for valuable supplies wanted for the inexperienced vitality transition.

The Metals Firm (TMC), which funded a few of the analysis that led to Sweetman’s 2024 paper, has been among the many fiercest critics of his findings. Its scientists have revealed a paper arguing the invention is “fully unsupported” by proof and elevating considerations concerning the research’s methodology.

“After many years of analysis utilizing the identical strategies, no credible scientist has ever reported proof of ‘darkish oxygen’,” Gerard Barron, the CEO and chairperson of The Metals Firm, stated in an announcement. “Extraordinary claims require extraordinary proof. We’re nonetheless ready.”

Different researchers have additionally raised considerations about Sweetman’s use of knowledge and say defective tools or misuse of the landers may have produced uncommon readings. Up to now, not one of the responses have accomplished the peer evaluate course of.

Considerations have additionally been raised with the journal that revealed Sweetman’s research, Nature Geoscience. “We’ve been wanting into [these concerns] rigorously following a longtime course of. Nevertheless, a call as to what motion could also be taken, if any, has not been made at the moment,” a spokesperson for the journal advised New Scientist.

Sweetman insists his research is correct and he can be responding to TMC’s criticisms in a proper rebuttal to their paper. However he says his expertise on the centre of the controversy has been “extraordinarily tiring” and upsetting. “There’s been a number of dialogue. Numerous mining corporations have been saying a number of various things, loads of it not so good, which has been a problem to dwell via,” he says. “It’s positively had a little bit of an influence on me. The web bullying hasn’t been good to be uncovered to, and it has been steady.”

Sweetman’s new analysis challenge, funded by way of a £2 million grant from Japanese charity The Nippon Basis, goals to put a few of the controversy to relaxation. Sweetman’s staff will use model new, custom-built landers able to descending to 12,000 metres beneath sea degree, twice the depth reached by the earlier research, to hunt particularly for darkish oxygen manufacturing within the Pacific Ocean.

The primary of three analysis expeditions will set sail in January 2026 from San Diego, California, with the purpose of confirming nodule-driven oxygen manufacturing within the deep ocean with recent information. As soon as once more, the landers will seal off samples of water and sediment from the ocean flooring to measure adjustments in oxygen concentrations. The researchers can even check for the presence of hydrogen, which might even be produced if seawater electrolysis is happening. And they’ll inject isotopically labelled water into samples to hint any chemical adjustments to the weather.

Sweetman is bullish concerning the prospects of discovering darkish oxygen manufacturing. “I do know it’s taking place. We’ve discovered this now in six locations. I do know we’re going to discover it,” he says. 

An additional two expeditions will search to analyze what microbial or electrochemical mechanisms could also be at play, and begin to discover the potential contribution of darkish oxygen manufacturing in deep ocean ecosystems. It’s the first analysis of its sort to instantly discover these processes – Sweetman’s preliminary discovery was, by his personal admission, “serendipitous”. “I didn’t got down to present this; we simply got down to measure sea flooring respiration,” he says of his preliminary work.

NASA can also be considering learning the nodules, Sweetman says, to analyze whether or not related processes might be supporting life on different moons and planets.

Deep-sea mining corporations can be watching the challenge intently. They’re hoping to start out operations later this yr, however are nonetheless ready for the Worldwide Seabed Authority to finalise its guidelines on deep sea mining. Extra proof of deep sea oxygen manufacturing would deal a extreme blow to their hopes of building a mining trade on the ocean flooring.

Sweetman says corporations ought to maintain off mining the seabed till scientists know extra concerning the potential position of darkish oxygen manufacturing in ocean ecosystems. “All we’re asking for is a bit more time to exit and check out to determine what’s going on,” he says.