How to Advance Deep Sea Technology using Metallic, Oxygenating, Geobattery "Flowers"

Question

So it turns out there DO be oxygen in the deep after all!

(Source)

"...small metallic nodules found in the north Pacific's Clarion-Clipperton Zone (CCZ) produce oxygen through seawater electrolysis, where seawater splits into oxygen and hydrogen in the presence of an electric charge."

"So-called polymetallic nodules are common on the ocean's abyssal plains, which are flat regions of the seafloor between 10,000 and 20,000 feet (3,000 to 6,000 m) below the ocean surface. These nodules mostly contain oxides of iron and manganese, but they also hold metals like cobalt, nickel and lithium, as well as rare earth elements such as cerium that are essential components of electronics and low-carbon technologies."

My Idea

I'm having my deep-dwelling race, that I've mentioned (before), take advantage of this incredible miracle by gathering and studying the nodules, in order to hopefully recreate them and help spread oxygen on a bigger scale.

Assume their current level of technology is earlier on the tech tree than the aforementioned post. Not sure what time period would be appropriate. Due to their lack of smelting, I'll go and say probably around the Neolithic Revolution Age? The discovery of geobatteries would seem to be their equivalent of fire but discovered comparatively later than ours. They are familiar with more advanced technology from land dwellers (who we'll say are in the 1400s Medieval stage equivalent just so we can have a point of reference) and the deep dwellers have even scavenged remnants from whatever washes or sinks into the sea. But being deep dwellers, they can't stay in the upper zones for too long. Especially in the daylight hours, which limits them to either dusk/dawn or night. So if there was to be any trade with others, it would probably be rather limited and tenuous at best. Not to mention any uses of above world technology would be limited for the lower depths.

As far as "mining" goes, I'm following the advice of others on this site (like here) by having them grinding, raking, and other repetitive motions for retrieving any deeper metals that aren't as easily accessible.

Using these metals, I want my people to be able to create the equivalent of plants from the land by making more geobatteries that use electrolysis to split water into hydrogen and oxygen. Possibly shaping them into floral shapes.

My hope is that I would like to put this on a large scale with the following characteristics:

• Large fields of these metallic "flowers" that can provide an oasis where needed (like public gardens, private yards, etc)
• Bigger "flowers" that (ideally) provide more oxygen
• Can be "planted" in or near future workshops to provide oxygen for things like smithing, building technology, burning things underwater, etc
• Improve standard of living for deeper folk, possibly aiding their metabolism and allowing more advancements
• Make the deeper zones more productive, even if slightly
• Possibility of leading to more advanced technological achievements like factories

What am I handwaving?

• I'm going to ignore the evolution of such a race and why they'd be in the deep to begin with for brevity's sake.
• Also for brevity's sake I'm going to assume that there'd be enough metals on the seabed to feasibly do this.
• Also temporarily ignoring why they don't find better ways to trade instead.

My Question! Can these geobatteries be able to oxygenate the deep sea enough to help the deep dwellers advance technologically?

Relevant questions that don't exactly answer my problem:

They both touch on electrolysis but this was before the geobatteries were discovered and made public knowledge.

• Could you develop Electrolysis with Pre-Modern technology?

• Electrolysis Assisted Aerobic Organisms

If there's anything else anyone needs to know, please feel free to ask!

Edit:

I altered my question in hopes of being more focused, and added more info. The deep dwellers are capable of:

• forming water tight containers for different reasons involving things from land
• studying the physics of pressure
• studying methods of preservation
• having access to brine pools and salts
• withstanding the heat of hydrothermal vents for a time

They lived in the mid zones of the ocean, traveling across them for various needs, before advancing enough (with the aid of discovering the geobatteries) where they were able to establish some settlements in the deeper zones. One of the reasons why they were so focused on advancement was to free themselves from relying on the land dwellers and wanting to get away from them.

(Debating on how this should work) They breathe oxygen and can store it in their bodies like cetaceans and even slow down their metabolism. However, they have gills like nudibranchs on their backs/sides which they can retract within themselves for protection or not in immediate use. In oxygen-poor zones or if they’re running low, they can create “emergency” oxygen by using electrolysis in nudibranch-styled gills. However, this is of course costly so it’s used sparingly.

Answer 1

Plausibility Checks

Geobattery / Electrolysis / Oxygen generation

• I think with those "nodules" you refer to the Manganese Deposits found in the deepsea.

• I could not find evidence on how much Oxygen is really produced by one nodule. I only found repeatedly "Oxygen levels rose". It is implied that the amount of Oxygen probably influenced the forming of our atmosphere. But the timescale is not mentioned. Does it need billions of years to form a meaningful amount of Oxygen by those processes (happening at 1.5V, no clue if it can be increased by doubling that voltage or something in that lane).

• Oxygen saturation of water: I think, your idea is to "add more oxygen to the seawater". But this is not going to work. Water is only capable of holding a finite amount of Oxygen. Depending on factors like depth/pressure, salinity, temperature. Any Oxygen that water cannot hold will be "gased out". Meaning it will form small bubbles and rise to the surface. From there it dissipates into the atmosphere. Over the course of billions of years "The Great Oxidation Event" on earth (and it is considered mainly caused by Cyanobacteria that produce Oxygen as a byproduct) the excess Oxygen became so much, that it formed the atmosphere in our today's condition (further processes for Nitrogen etc. not considered here).

  --> This means, you can assume that our oceans are totally saturated with Oxygen (as physically possible; there are low-saturated zones also). If you add processes to produce more Oxygen underwater, this will be a very slow and localized effect and only rise upwards (gas is lighter than water). Oxygen will not spread in the ocean (because it is saturated already).

Mining

• Those nodules are also called "Polymetallic" because they are a good mixture of traces of different metals. Primarily Iron, Nickel, Cobalt, Copper and Manganese of course. Along with precious metals, like gold, silver, and Rare Earth metals in ever diminishing amounts. All those metals are tightly bound together and are oxidized, meaning they are not pure, but have all formed reactions with Oxygen.

• The nodules are very interesting for us (our modern demands on technology) because those nodules contain everything we need to make batteries and high-tech stuff like computer equipment of all sorts, CPUs, hard drives, SSDs, memory chips, electro-motors, coils, condensators, capacitators, ferro-magnets, LEDs, nano-technology, etc. etc. - And we are short on mining sites above sea-level to satisfy ever growing demands (also: political reasons because those metals are "rare" and localized on certain spots).

• You said your merfolk is at the level of neolithic time. Their demands would be highly focused on Iron and Copper in great abundance, Nickel maybe also to form alloys. Ferro-magnetic properties of Nickel, Cobalt and Copper might be interesting to individuals (scientists), but all others probably value those only as juwelery. All Rare Earth Metals are totally useless to them until they have need for semi-conductors and computer technology.

• Smelting of "Polymetallic Manganese Nodules" needs a great deal of knowledge and a highly sophisticated smelting process to separate all the metals without losing to much of it. Also Re-Oxidizing the metals is something special.

  They might be able to "brute force" smelting only the main metals and knowingly or unknowingly discard the others (they will form the clinker/waste even more munched together and harder to separate).

• Needs: If your merfolk is in need of the primary metals (iron, copper, nickel), then there is either "better ore" available somewhere with much higher yields of those metals or they are in need of trade with the landfolks.

Trading

• Since the landfolk is more advanced, maybe their demands are different and they are more after to precious metals, even if they are in smaller traces, but being "gifted" to them by the merfolk as trading items or even as kind of "currency", makes it easier to smelt those brute-force for gold and silver only, than trying to find and mine gold and silver themselves somewhere far away and hard to reach. Maybe this "Manganese Ore Trading" becomes a thing between the two folks. Merfolk providing the ore, landfolk providing the smelting and smithing.

• The merfolk surely has two mega advantages: (A) They have the resources and (B) they can reach and harvest them fairly easily even (because, underwater breathing and intelligent enough to use tools, and the potatos just lying around, not being held in stone etc.). That gives them a de-facto monopoly which they can utilize to trade with the landfolk for all kinds of stuff.

Technological Advancements

• As I understand it, the merfolk has grills or some natural ability to "breathe water". Do they really depend on Oxygen? Or is more Oxygen and less water even deadly for them (like for a fish on land). The question is: Would they really want a higher "oxygen atmosphere" in their underwater sea cities?

• The second thing is, the technological stuff. Like being able to smelt, weld, explode, light etc. underwater. (There are ways to achieve this underwater also, like plasma welding, Thermite or phosphorous reactions).

  I think to be used like at the surface, you need kind of a evacuated base, a sealed house or dome in which the Oxygen atmosphere can dominate and the amount of water can be reduced or removed entirely. This would come down to them as if we would be underwater or in space. Meaning, they can only operate there with special breathing equipment.

Conclusion:

I don't think the pure presence of those nodules can advance you merfolk in a revolutionized way. To make the best use of it, they need to advance their base tech-level first. They do have advantages when it comes to trading with the land people. Increasing the oxygen levels underwater without further technological explanations (underwater domes etc.) is not possible (or only in restricted amounts) and the health impact on merfolk needs to be addressed.