Scientists just discovered a source of dark oxygen deep in our oceans. No dark oxygen isn’t the opposite of oxygen like dark matter, it’s just a source of oxygen that shouldn’t be there. 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. But this could upend what we think we know about our oceans, and even the origins of life. So what exactly is this source of dark oxygen, and how profound an impact might it have for all of us here on Earth? Let’s figure this out together, I’m RIcky and this is two bit da vinci.
Huge thanks to our community member Crissa for sharing this story with us, and don’t forget to join our discord and newsletter to help us make future episodes.
Until now, it was widely believed that oxygen was produced solely through photosynthesis, a process requiring sunlight.
And dissolved oxygen in the deep sea was believed to have been transported there from surface waters. It can be generated at the surface by plant life via photosynthesis or diffuse from the atmosphere as a result of wave action
However, researchers led by Professor Andrew Sweetman from the Scottish Association for Marine Science have discovered what they call ‘dark oxygen.’
Sweetman made the discovery while sampling the seabed of the Clarion-Clipperton Zone, a mountainous submarine ridge along the seafloor in the north-east quadrant of the Pacific Ocean.
And in classic scientist fashion, when his team first detected oxygen, they assumed their equipment was faulty.
Sweetman says, “When we first got this data, we thought the sensors were faulty because every study ever done in the deep sea has only seen oxygen being consumed rather than produced,”
“We would come home and recalibrate the sensors, but, over the course of 10 years, these strange oxygen readings kept showing up.
“We decided to take a back-up method that worked differently to the optode sensors we were using. When both methods came back with the same result, we knew we were onto something ground-breaking and unthought-of.”
In the summer of 2023, Sweetman reached out to Franz Geiger, a chemist at Northwestern University to see if he had any idea what was going on. Geiger’s previous research had shown that rust, when combined with saltwater, could generate electricity.
This led the researchers to hypothesize that polymetallic nodules in the deep-ocean might have something to do with it.
Polymetallic nodules contain very valuable metals such as manganese, nickel and cobalt, the very same materials we need for lithium ion batteries for EVs electronics and home batteries.
Remarkably, the surface of single nodules generated up to 0.95 volts, which isn’t quite enough to split seawater into hydrogen and oxygen via seawater electrolysis. But just like batteries which you can place in series, much higher voltages were observed in areas where the nodules clustered together, producing more than enough voltage for the task.
To test this theory, Sweetman shipped several pounds of polymetallic nodules, collected from the ocean floor, to Geiger’s lab at Northwestern University.
It actually turns out just 1.5 volts the same as a AA battery, is enough to split sea water.
“It appears that we discovered a natural ‘geobattery,’” Geiger said. “These geobatteries could explain the ocean’s dark oxygen production.”
At this point in the video, you may be thinking, humanity and mother nature may be on a collision course. On one hand, we may have just found a massive deposit of battery grade materials that could power GWh of battery capacity in the coming decade, a decade with a massive battery appetite. And on the other hand, we may disrupt oxygenation in our deep oceans, the most powerful engine of all life on Earth.
And you wouldn’t be alone in thinking that. In fact several companies conducted exploratory deep sea mining excursions during the 70’s and 80s, in hopes of finding the next gold rush. And there is new interest from new companies to pursue the very same goals. But Geiger warns,
“A few years ago, a team of marine biologists went back to those areas that were mined 40 years ago and found essentially no life,” Geiger said. “And then a few hundred meters over to the left and right, where the nodules were intact, plenty of life.”
Understanding now, that it’s not just ocean currents and circulation that bring oxygen rich waters deep to the ocean floors, but that oxygen is actually actively produced by these geobattery nodules, kinda changes everything.
I remember reading about bottom trawling, a fishing tactic that drags heavy weighted nets along the seafloor, to catch large quantities of fish and everything else all at once.
It’s a practice that’s not as common today, because it catches everything indiscriminately wreaking havoc on ecosystems, but arguably even worse, destroys deep sea coral forests, which are some of the most biologically diverse ecosystems on Earth.
Deep sea mining has always been concerning for many of the same destructive reasons. But now things get even more complicated, because the very metals we need for batteries might starve our oceans of oxygen.
And the timing of this discovery couldn’t be worse for companies that have touted deep sea mining, as the eco friendly solution, and one that’s less destructive than conventional mining on land.
Landing mining is surprisingly destructive, with most ores with only a few percent of concentration of the metals we need. That leaves most of the ore as waste tailings, which are often toxic and difficult to deal with. If you want to learn more about mining, and hear about new more environmentally friendly approaches, check out our video we did on Nouveau Monde graphite, a company in Canada that’s dedicated to sustainable and responsible mining for graphite.
Ironically being the more humanitarian and environmentally friendly choice have been the benefits that deep sea mining companies have leaned on. And if you’re wondering just how much of an impact these nodules could have, according to DeepGreen Metals, the polymettalic nodule fields of just one region in the Pacific ocean, which represents the largest known underdeveloped nickel resource on Earth, contains more than enough battery materials to power 1 Billion EVs.
Which region of the Pacific you ask? The CCZ or the Clarion-Clipperton Zone, the very same place where Professor Sweetman first made this discovery. (link)
With so much of our oceans uncharted and understudied, I wonder if this one nodule rich region is a super rare fluke, or just one of many such deposits. The nodule resource just in the CCZ is now estimated as 4 megatons (Mt) measured, 341Mt indicated and 11Mt inferred mineral resources.
The greatest draw for mining these resources is that these nodules literally contain Nickel, manganese cobalt and copper all ingredients we need for batteries. This is nearly unheard of in land based mines, which both have much lower concentrations, but rarely have a buffet of everything we need.
The other great draw is that the deep sea floor clusters of nodules are a 2-D resource, and with some surveying you can measure and survey exactly what you can expect.
Traditional land mining in contrast is 3d, meaning you have to drill down to unknown depths to know exactly what you have and in what concentrations.
This latest discovery of dark oxygen is likely to impact all future deep sea mining projects in profound ways. But just how impactful deep sea mining of these nodules can be, is very difficult to predict. We’re just now starting to learn about deep sea conditions, and it’ll likely be many more decades because we can predict anything with any kind of certainty.
So what do you think? It’s as if we’ve struck gold, finding high concentrations of all the materials required to make all the batteries we need, but to only discover that those same battery rocks may be responsible for some part of the oxygen being generated deep in our oceans.
Where would you draw the priority, and how should the world proceed? Our oceans are deeply connected, and while land and mineral rights may be bestowed to some country or company, the impacts of our activities is surely going to impact all of us.
Now I should point out that these findings By Andrew Sweetman, Franz Geiger and many others has been peer reviewed and published in Nature as of July 22, 2024. But like all scientific pursuits further corroboration and testing will likely be done in the coming months and years.
And let’s not forget that in the process of producing oxygen, splitting water also produces hydrogen… might there be a way for us to produce, capture and export hydrogen from our ocean depths to provide a steady supply of clean hydrogen? Its an interesting question, and one i’d have to research for a future video. Let me know if that’s something i should look into. And while you’re at it, if you think i’ve earned it, i’d love it if you hit that subscribe button and join us in our journey exploring the world. Like i mentioned this topic came to us from one of our channel members, who literally help guide what we make next. And you can too.
ANd if you’ve made it this far, check out this video we made on fertilziing our oceans with rust, a crazy idea that someone actually tried. Ok see you next week.
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