This narrative received funding from the Pulitzer Center and was also published with the Post and Courier.

On July 22, 2024, a groundbreaking revelation was made by a group of scientists: they found that certain deep-sea rocks were generating oxygen in the pitch-dark depths of the ocean.

We were in the midst of producing a documentary on these peculiar, potato-sized seabed formations called polymetallic nodules when suddenly, they became a hot topic worldwide. The phenomenon was named “dark oxygen” by the researchers.

---

Supporting Science Reporting

If you find this article engaging, please consider supporting our distinguished journalism by subscribing. Your subscription aids in sustaining our ability to deliver compelling narratives about groundbreaking discoveries and concepts that currently shape our world.

---

What captured our interest as journalists was the swift impact this research had. Within a few days of its release, it sparked discussions among numerous diplomats gathered in Kingston, Jamaica, who were there to determine the fate of these nodules.

It’s uncommon for scientific findings to influence policy so quickly.

Published in Nature Geoscience, the study on “dark oxygen” led delegates from Costa Rica and Panama to argue for a slower pace in the negotiations. Under a United Nations treaty ratified by 170 countries and regions—excluding the U.S.—companies are not allowed to harvest these nodules from international waters without a consensus on the regulations governing such activities. “Dark oxygen” called for caution before the commencement of deep-sea mining.

This discovery shifted the trajectory of the documentary we were already filming. We had been following another team of scientists who had discovered the oldest deep-sea testing site for mining, over 50 years old.

This earlier discovery, however, had met a very different destiny.

Our journey revealed a story about the power of scientific research in extreme settings. What captures public interest? What influences policy? Is it merely about timing and luck?

The “dark oxygen” study has faced scrutiny over the past year. Researchers from the University of Aberdeen in Scotland and from two companies—The Metals Company and Adepth—have issued scientific counterarguments in preprint papers. Yet, Nature Geoscience, which published the study, along with its authors, continue to defend it.

A representative of Nature Geoscience communicated via email that they are conducting a thorough review following standard procedures, which has not yet concluded.

The decision on whether to proceed with mining in international waters is still pending. This month, delegates reconvened for discussions in Jamaica. We were there to observe, noting a marked slowdown in the process compared to last year’s quick pace towards what seemed like inevitable mining operations. Prudence has overtaken urgency.

TRANSCRIPT

Clare Fieseler (reading from her 2024 Post and Courier article “Pulled from the Deep”): “Around 10 million years ago … the ocean teemed with creatures…. As they moved, debris fell to the ocean floor, including stray shark teeth, which mixed with volcanic rock fragments below. Over time, these fragments began to accumulate trace metals from the ocean’s chemical mix, forming layers rich in essential minerals like manganese, nickel, and cobalt. For millions of years, in total darkness, these rocks grew steadily across the world’s oceans.”

Fieseler: My name is Clare Fieseler. I’m both a journalist and a scientist, and I’m here speaking with a microbiologist who, together with his team, has discovered something extraordinary at the bottom of the ocean.

Jeff Marlow: You could typically hold a nodule in your hand.

Another.

And as you get closer, you start noticing different textures. Get even closer, and you begin to see life on them. They aren’t just barren stones; they can also serve as substrates for animals. There are worms that crawl on and within the nodules. There are tiny corals that protrude. They might only be a few centimeters tall—insignificant from our perspective—but they are like the giant sequoias of the abyssal plain.

This is what we saw—just, like, millions [laughs] of these nodules covering the seafloor.

They are everywhere. It’s all about taking a closer look, viewing them from a different perspective that unveils something incredible.

Fieseler: You seem a bit reluctant to say something like: “We found that nodules might be producing oxygen.” [Laughs]

Marlow: Mm, um.

Fieseler: Is there a reason?

Marlow: Is there a reason [laughs]? [CLIP: Carolyn Beeler speaking on PRX’s The World: “The discovery is that metals on the ocean floor can create oxygen without photosynthesis. They’re calling the oxygen created this way ‘dark oxygen.’”]

Fieseler: There’s a reason why Jeff Marlow is being cautious with me. His collaborators—Andrew Sweetman, Franz Geiger, and the rest of their 16-person team—published a study in Nature Geoscience that could transform not just our understanding of these nodules or the ocean; it could alter our perception of how life itself began on Earth.

These scientists aren’t the only ones interested in polymetallic nodules. An entire industry is eager to extract these nodules from the ocean floor for profit. In fact, the team’s research was sponsored by The Metals Company, one of the primary entities advocating for deep-sea mining.

Marlow: Through extensive data and meticulous problem-solving, we concluded that the nodules—or something within or around them—were producing oxygen.

Federica Calabrese: Exactly like that, so I …

Fieseler: I see it there.

Calabrese: Yeah, especially here, you can …

Marlow: That’s how science works; it’s confusing, it’s messy. Through experiments and thoughtful analyses, you uncover the real story, and I think we’re just at the beginning of that.

Fieseler: To get a better grasp of all this, I reached out to an old friend, Andrew Thaler, a deep-sea ecologist who once managed the only trade publication for the deep-sea mining industry. He’s been following this topic for years.

Andrew Thaler: The reason we want to mine the deep sea, the reason we need these metals and minerals, is because we want to transition away from fossil fuels. To do that, we need to rapidly electrify the world’s power grids.

Generating energy through renewable sources means needing energy storage, and energy storage means batteries. Polymetallic nodules are—you’ll hear this often when mining company CEOs speak—they’ll hold up a nodule and say …

[CLIP: Gerard Barron, CEO of The Metals Company, appearing on 60 Minutes: “That is an electric vehicle battery in a rock.”]

[CLIP: Barron speaking on 121 Mining Investment TV: “This is like a battery in a rock.”]

Thaler: “This is a Tesla battery.” And they’re not wrong.

Fieseler: The most valuable nodules are found in the Pacific between Hawaii and Mexico, in a region known as the Clarion-Clipperton Zone, or CCZ. For over 50 years, mining companies have been testing equipment and conducting environmental studies to determine the potential impact of mining on the abyss—because no one knows for sure how long the seafloor would take to recover. So I traveled to Woods Hole, Massachusetts, to speak with Jason Chaytor, a federal scientist who studies the seafloor.

Jason Chaytor: My motivation for studying nodules wasn’t actually about the nodules themselves.

So here is, actually, the Data Library.

I was just looking for an area to examine how the seabed adapts to changes over time. Oh, it’s here somewhere [laughs].

In fact, for this project, I searched for some maps and navigation data and realized the original records were typed out on sheets of paper.

I stumbled upon a museum finding aid from the Mariners’ Museum in Newport News, Virginia, that referenced the ships Deepsea Ventures had used in the late 1960s and 1970s in connection with the Blake Plateau.

Fieseler: The coordinates had been lost to history because Deepsea Ventures went under just 20 years later. Other companies tried; none succeeded. Mining the ocean floor never made financial sense.

After five years of searching for the coordinates, organizing an expedition, Chaytor and his team revisited the Blake Plateau off the coast of South Carolina in 2022 to rediscover a lost deep-sea mining test site—the world’s oldest—and observe how the seafloor had changed.

[CLIP: Scientist audio: “As we mentioned before, this was a previous—a testing site for deep-sea mining, which took place in the late ’60s, early ’70s.”]

Chaytor: My initial impression of that field—it’s astonishing.

It looked like a field of crops—like a field of nodules scattered everywhere.

The first signs of disturbance we observed looked like long train tracks through these fields of nodules—areas where nodules were piled up, separated by open sediment with no nodules—and they just extended into the distance.

We ended up with more than 550,000 photographs. What we’re doing is merging them together to create a seamless picture of the seafloor.

Now, 54 years later, some of those tracks look like they were just recently made.

They are coated with ferromanganese crust. In most cases, what’s inside them …

Fieseler: Do you know what that is?

Thaler: That looks like a dredge track on an abyssal plain.

Fieseler: You are the first person to see these.

Thaler: So there’s no recovery.

Fieseler: Yeah.

Thaler: I mean, it’s not really new information. Like, we know that recovery doesn’t happen over decades. Like, I’m sure this is what everyone expected to see.

Fieseler: Yeah.

Thaler: It is quite dramatic, though.

Fieseler: Yeah, it’s one of those things where it’s like, “Oh, this image could change everything,” or it could change absolutely nothing because people don’t understand it.

Thaler: I mean, like, most people, like, wouldn’t have any context for what this is to begin with.

Fieseler: We’re here at the largest gathering of ocean scientists in North America right now in New Orleans.

There are a few scientists here presenting their own research on deep-sea mining, so I’m going to be talking to a few of them. And then we just wait until 4:00 P.M. to see what happens when Jason Chaytor presents his findings at his poster session.

Thaler: So this is it.

Fieseler: Mm-hmm. These are all the tracks.

Thaler: Oh, wow, and you know what’s really interesting about the site is that a recent publication revealed the largest deepwater coral reef in the world on the Blake Plateau, and it’s about 20 kilometers [roughly 12.4 miles] from the site.

Fieseler: Yeah.

Thaler: It’s, like, right there.

Fieseler: Yeah.

Thaler: So the very first time anyone attempted experimental deep-sea mining, they almost hit one of the largest coral reef systems on the planet.

Fieseler: Yeah.

Chaytor: Whether it has a major impact is not what we’re after. We aim for it to be useful.

Essentially to inform people of, you know, it’s not a perfect analogue for the current activities, but it’s like, “Yeah, it does take a long time for something to recover—if it recovers at all, so.”

But it’s also the nature of science; it’s kind of this accumulation of information and knowledge.

Just because it comes out and I don’t get a whole bunch of phone calls—you know, it’s not why, you know, we do the work that we do, especially as a government scientist, because there is a reason for doing it. There’s a mission. There’s a purpose. There’s a goal.

Fieseler: After just two hours the poster session ended.

Fieseler (reading from her 2024 article): “Four security guards herded the scientists out and turned off the lights…. Chaytor was certain that scientists decades from now would see its value. That’s what mattered to him. [But] for non-scientists, this unique view about human destruction in unreachable places may fade into history’s footnotes once again.”

Fieseler: Chaytor remarkably discovered this old mining site in U.S. waters, but today the nodules that most miners want to get at are out there, in international waters, which are currently protected by the United Nations Convention on the Law of the Sea. It’s a treaty ratified by most of the world’s countries.

The law says the international seabed is special, like the moon, like Antarctica. It is legally designated “the common heritage of mankind.”

But there’s a catch: countries of the world can vote to open up the seabed to mining if they can agree on a code—a set of rules that would govern commercial activities out on the high seas. The organization in charge of these negotiations is the International Seabed Authority, or ISA, a United Nations–affiliated group. It is currently meeting in July 2025 in Kingston, Jamaica.

<

Similar Posts

• Shocking Discovery: How Corals are Battling Rising Ocean Temperatures!
• Man Who Lost $780 Million in Bitcoin Plans to Buy Landfill Before Closure
• Oceans Darkening: Emerging Threat to Marine Life Unveiled!
• Undersea Cables Severed: How Microsoft Averted Disaster
• “City Killer” Asteroid Threat to Earth Spikes, Then Drops – Latest 2025 Update!