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Comment by TSiege | Hacker News Reader

This is a subject that will likely hinge on politics and commodity markets, but the science is very clear as is occam's razor

1. There is a lot of animal life in the deep ocean where these modules are present and absent where they are not

2. Those organisms depend on oxygen to function

3. Polymetallic nodules taken from the deep ocean have been shown in lab conditions to create enough of an electric charge to split H2O into H2 and O2

4. Areas where polymetallic nodules have been removed decades ago haven't recovered even on a microorganism level

5. These nodules individually take *millions* of years to form

From these conclusions we can safely assume that removing them would decimate these ecosystems on a timescale that's longer than evolution of the genus Homo. Put another way it would be as if we cut down a forest knowing it would take millions of years for individual trees to regrow. It is a crime against the planet to remove these nodules

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What is the source of the electricity generation? Presumably, given how slowly the nodules form, they must be acting as a catalyst/not be being consumed, so what energy source are they using?

They believe it's due to the metals that make up the nodules creating differences in electrical charge along their surface and perhaps between nodules. For an in depth explanation see below

https://eos.org/articles/metallic-nodules-create-oxygen-in-t...

https://www.nature.com/articles/s41561-024-01480-8

So it appears that the authors actually don't know. Specifically they say:

Whereas questions remain concerning this potential mechanism (such as the identity of the energy source(s), longevity of DOP, catalytic stabilities, electrochemical conditions on exposed versus buried nodules surfaces and the influence of different chemistries within the nodule layers

And after reading their explanation for why they discount microbial sourcing of the oxygen, I am inclined to join other commenters in their skepticism. Given no good mechanistic understanding, I think they are being too quick to rule out microbes. That's not to say that they are wrong, just that I think their current evidence isn't strong enough to support the claims they are making (admittedly this is a completely subjective assessment)

I believe electrolysis occurs between any two metals in a fluid conductor (like salt water). This happens in boats, which is why you put a "sacraficial zinc" on the hull so that your prop and prop shaft and through-hulls don't erode. Maybe this could generate small amounts of O2 at depth, but not a chemist so I don't know.

As you point out, that causes corrosion, using up the metals (well, using up their galvanic potential energy anyways). These nodules are A) extremely old and B) extremely slow growing/generating. If that were the source of the electric fields, it couldn't be sustained long enough to be a stable source and it would result in the nodules corroding away (or at least one of the metals corroding until there was no longer electrochemical potential, which would end the effect).

In other words, for that to be the source, then that would imply that something about our understanding of how these nodules form would be off by many orders of magnitude.

They would have to be forming so quickly, that the concerns about using them up would almost go away (assuming that harvesting didn't disrupt the process of formation that is).

Part of the reason why there is concern here is that these nodules (as we currently understand it) form so slowly (literally millions of years), that if we harvest them, then they are, for all intents and purposes, gone forever. So if they do have important ecological functions, then those functions are completely wiped out.

But if they are actually forming on the order years (and I can't imagine that it could possibly be any slower than that for galvanic/corrosive processes to be the answer, and in fact probably faster), then that concern goes away. Harvest one section of a field, go away for a decade, and it's restored.

How do the nodules form? I'm not sure of the mechanism but I can speculate that it may be that they form as a result of biological action of microorganisms which take in seawater and secrete heavy metals. Colonies of these microorganisms could coalesce to the point where their presence is indicated by the presence of these nodules.

Perhaps using thin sections of the nodules will provide a clue about their origin and whether they are a biological type of sedimentary deposit or something that occurs due to chemical or electrochemical diagenesis of existing sediments or alteration of suspended particulates in the water column.

It's interesting that they are only found in areas where the seafloor is oxygenated according to the EOS article linked and quoted below.

>Nodule provinces are not typically found in low-oxygen areas, she said. “However, there could be microenvironments where oxygen is depleted and dark oxygen production enables certain microbes, protozoa, or fauna.”

If it is being produced down there, something is using it. Everything is part of a cycle and works in concert with all the other parts keep the wheels turning. If we remove enough parts the cycle ends.

I think we need to understand the role these nodules play in their environments before commercial interests start crowing the familiar "national security interests" argument to allow them to bypass any scrutiny.

I was thinking if a log burning is a realer of stored energy these modules might demonstrate the same energy harvesting as plants but on a muncher longer time scale.

An interesting side question, but not relevant to the argument.

These nodules aren't even that valuable. It's not like they're full of Platinum group metals...

Privatize profits. Socialize costs.

If you're in international waters, you can destroy whatever you want and even at low marginal return, if you can scale fast enough the total ROI can be good. The solution to pollution is dilution (of regulatory barriers)!

I've been following this for years and am somewhat ambivalent to either outcome.

I feel the need to warn anyone reading that this is an overwrought reaction to an overwrought reaction to a, well, very opinionated take.

There's a reason why there's 5 papers as refutations, and no one will even go on the record, even just for a news article that'll play well to general public grousing, to even devil's advocate for the original paper

I'm glad institutions have and are taking their time with this, to the point we're being steadily brought along, publicly, as we investigate the possibilities and perhaps even discover new things along the way.

Frankly, I don't have a dog in the fight either. I have to wonder if those writing the refutations do.

But frankly, if it is viable, it will be done by one of the majors. Just look at the overfishing problem. Then everyone will just buy from them and ignore the destruction. Like all the other tragedies of the commons, it takes leadership to avoid them (and shame, or at least a desire for truth) that this world does not currently have.

Couldn't we re-seed these areas with artificial nodules? Could we seed areas w/o previous nodules to create new areas for undersea life? Is there a project doing this yet?

This is a great question, and I dont understand why it was downvoted.

I don’t think we have a great track record at fully understanding these complex biological systems well enough to engineer life.

you dont really need to understand how something works to know if it works.

theres 8 billion of us because of farming. most of the farmers dont really know how it all works.

woudln't it be cool to make nodules and go drop them in barren parts of the ocean and then they become seeded?

...Ag science is a bloody thing, and if you don't think it takes a lick of knowledge to be a farmer, I welcome you to try being one yourself in order to free yourself of this frankly distateful, nay, disgusting hubris.

I acknowledge that industrial farmers go to university, etc, but of the 8 billion people, most of the farmers probably dont really know whats going on. they just know what to sorta do with the plants.

which was true 10,000 years ago before humans even know what cells or photosynthesis was. people had farms then.

so the point is, even without a genuine understanding, if the causal relationship between seeding parts of the ocean and the desired result is achieved, then an understanding wouldnt be necessary.

Sounds like we need to find a way to recreate these metal rocks in a lab and start seeding parts of the ocean with them.

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