Worldbuilding 201: Aquatic civilisations
Greetings and solutions! Wait… salutations! Actually, let’s go with solutions, I solved some math stuff! Anyway, Hi! Welcome to my blog with your favourite alien Limax, Vivian! This time, I will talk about a thing that is often done but rarely thought of much: aquatic civilisations! A sapient species could live in water, but what could it be like? As usual, this is not exhaustive, and I might return for more!
More than water
While water is the most common oxidised liquid… what do you mean it isn’t oxidised, just water? Bob, for the love of Divinum, shut up! It is burnt hydrogen! Someone show him to the airlock! Anyway, it is very common because hydrogen is the most common atom in the universe, and due to how the nuclear processes work within a star, oxygen is very common too, relatively speaking.
But the thing is, it doesn’t NEED to be water. It can be any liquid that allows life to exist in any temperature range where it remains liquid. Saturn’s moon Titan has methane oceans and rain; you could have undermethane civilisations at such a place! But this does require you to go to way lower temperatures than we are used to. But hey, it might be really good and interesting for your weird story!
Evolution
The evolution of such life can be quite different. We have dolphins being highly intelligent, same with octopi and many others. But neither of those will be making a civilization anytime soon, and I will explain more why later, but both have an advantage the other lacks.
For octopi, they have the advantage of having prehensile appendages, namely their wretched tentacles. No… don’t go there…. NO! Bad naughty human! They can grab stuff, manipulate said things with them, and do all kinds of things. Anything you can do, they can do better! They however have one big issue that makes their rise to an aquatic civilization close to impossible… no generational knowledge or methods to acquire it. The females lay the eggs, the father does not care, and then she guards the eggs until they hatch at which she is already dying due to lack of eating. Sure works to keep their species going… not so good for civilization building.
Dolphins are the polar opposite. Just as intelligent, can problem solve like crazy. They form strong social relations with each other and others, do VERY bad stuff too, so they are ready for war at least. But all they have are these tiny little fins that they can barely move. They cannot manipulate objects without using their nose and such. It is not very fine manipulation of anything. This means they will never make a civilisation worth a damn, no matter how ready they are to commit war crimes.
So when designing them for a civilisation, keep this list in mind:
Prehensile appendage
Capable of manipulating objects precisely
Method of communication
Transfer of knowledge
Generational knowledge
Actually, this goes for any sapient form of life that makes a civilization.
Advantages
Of course there are some advantages! And problems, but start on a high note!
Lack of Gravity
Within a liquid, the Archimedes principle that any fluid will apply a force opposite to gravity equal to the weight of the displaced fluid by the object in the fluid, is much stronger. On earth in the air, for example, a human that displaces 65 litres of air will weigh about 0.065 kg less, or about 65 grams. Not much at all, but the same body in water and suddenly you have 65 kg of force less pushing you down! Which given that the body is mostly water anyway means that almost all of your entire weight is being counteracted by the water itself.
So after that head breaking part, what does that mean? That gravity is, for the most part, little to no concern. Even if they use building materials that are heavier, it will still feel lighter for them. This however does mean that people used to moving around in 3D unhindered are likely to find the sudden need to move close to the bottom of the sea very restraining.`
Abundance of food
It might look like the oceans are almost entirely empty, and relatively speaking, by size, it has very little food, but appearances can deceive! It is actually extremely abundant, in the form of plankton. Plankton are tiny animals, plants, and such that float around in the oceans. If you have more kingdoms, you can actually make more plankton! The only criteria for them is that plankton cannot swim against even the tiniest of currents.
Plankton are one reason why the ocean is a big producer and consumer of oxygen. And of course animals and life will take advantage of this enormous abundance of food. That is why filter feeders are popular, and have the benefit of the bigger you are, the more you can eat! So for an aquatic civilisation, you could have their agriculture be based around sessile filter feeders and their livestock be motile ones.
Stable environments
This section is mostly related to the next part but even on Earth, relatively speaking, water environments are relatively stable. This does not, however, mean it never changes. It changes however much slower. The difference between one hour and the next is miniscule, day to day is barely perceivable. It takes many weeks for water and its environment, temperature, and such, to change. A lot of this is related to the temperature and sunlight which does not change fast for water.
But on rogue planets… actually, let’s go there.
Rogue Planets & Super Earths
Rogue planets are rogues, but in what sense? In the sense that they have left the confines of gravity and finally escaped from the tyranny imposed by their star! Freedom awaits it! Okay, I went a bit Anne there I think. This means they have no sun to give heat and can only rely on internal heating from the geological activity below, which comes from radioactive material decaying and physics to generate heat.
So either these worlds have really thick atmospheres to help keep the heat in and prevent water and the atmosphere from freezing in the endless cold space, or it doesn’t have that, and the top turns really bloody cold and you have km of ice before it turns liquid again as water is heavier as a liquid than as a solid. In this water, you can have a civilisation arise. It will be aquatic, its entire food web will work very differently, but it can work. Imagine the kind of mythology these people would develop about the ice above: was it placed by the gods? Is it a punishment by the gods? Is there anything that lies beyond the ice? They will never know. But because all energy comes from below and is rarely ever going to change, the environment is as stable as it could ever be.
Super Earths are really big planets with large gravity that presses down REAL hard. This makes terrestrial life much harder, as each fall becomes more and more difficult. At one point, flying is impossible. At another point, any kind of falling over from your own legs means death. And at some point, even reaching space becomes impossible. But as we discussed before, gravity is not an issue in water for the most part! So maybe they stay in water and are now wondering about land.
Challenges
So while an aquatic civilization may have some fun advantages to terrestrial civilizations, there are also some severe issues that they need to deal with.
Water’s heat capacity
This one is good in the sense that it helps keep the environment stable as any changes in temperature outside the water takes a lot of energy to pass into water as water has very high heat capacity compared to air. On the negative side, when it starts getting warm or cold it is really difficult to change the temperature. If you have a heat source that gives off a lot of heat, sure it takes a long time before you feel anything, but if that water gets too hot due to this and someone being a dumb arse, that also takes ages to reach a temperature where you can go back into the water without turning into boiled fish. Do you boil fish? Well, either way, boiled they get!
If it is cold it is going to take a lot of energy to get it back up. You cannot simply light a fire and quickly get the room up to temperature. It’ll take ages again!
Resistance/Viscosity of water
Moving through air is easy, that is why most terrestrial life comes in many different forms. The air easily gets out of the way, and through it we move! Water, not so much! It is as thick as Bob and really does not want to move out of the way. Which is why aquatic life has evolved the same fish-like body shape to move through water quickly. Bottom living aquatic life shows greater diversity, but they are rarely fast moving and can easily be snapped up by fast swimmers from above. Imagine yourself living in an environment where you walk on the ground, and you see sharks 2-9 times the human size hovering above you like it's nothing. Pretty scary!
This is also why dolphins lack thumbs and the like on their stubby little fins! Those increases drag which slows them down. So a civilization making creatures under the sea!--no don’t sing that–is likely to be a bottom living one over a swimming one.
Prehensile appendage
Because of said viscosity, large structures that can manipulate objects, even more so manipulate them in a precise manner, causes immense amounts of drag. So if you want a fast swimming people like merpeople, this is something to overcome. If limbs are aligned with the body during the swim, it will reduce drag, but all that extra structure still causes more drag than not having the limbs. But who knows, maybe they were created by gods, or you just go “Eh fuck it” and does it anyway. I have done that!
Oxygen supply
Oxygen is plentiful in the air, but that is because gases can easily be mixed together. Liquids and gases do not mix well. All liquids, including water, will dissolve some gas if they are in an environment with a gas and a pressure that is forcing it into the liquid. But it is significantly less than the air. This is one reason why most large aquatic animals come from former land animals that breathe air rather than have gills. But you have seen how large sharks can get, so it should be within the range you likely want.
Metallurgy
Remember the oxygen issue? And the heat capacity of water? Yeah, all of those are big reasons why fire does not work in water. What is it that fire needs? Fuel, heat, and oxygen. The heat capacity makes it so that a lot is easily transported away, and thus the heat is disappearing. Then on top of that, water has a max temperature before it starts boiling and all additional energy just goes to boil it, and thus it is even more consumed by the water rather than the fire. Then the lack of oxygen makes it even harder to keep it going as water is not moving fast enough to supply it with the constant required amount of oxygen to sustain it. Fuel is the easiest to handwave in.
The lack of fire and easily controlled heat sources means that metallurgy is going to be extremely hard if not impossible. Without metals, a lot of technology we are used to is simply impossible. Even early technologies relied on metals. Sure, they might not need tools for agriculture due to using animals more like I suggested above, but what about building homes and houses? Rocks can work, but that is difficult. This essentially means that aquatic civilisations are likely to get stuck at best Roman tech level before they cannot progress anymore due to lack of metals.
Unless you magic up something that can burn underwater and is immune to these constraints. Easily done in fantasy, harder in scifi, but soft scifi GO!
Technological stages
As said, due to lack of metallurgy having them advance really far is highly unlikely. But let us assume that you have it so they can make metals, make tools, they are climbing up the tech tree! They know how to play the game of civilization! What can we expect? If we operate under these assumptions, up to renaissance technology is likely to no longer be an issue. Gunpowder and cannons have the same issue as before. But we already said they found a way to make it work, so this one works as well by extension, only that their concoction is different from ours.
Industrialisation can now start giving us problems. While we have had them mastering fire and all that, the heat problem was never removed, only that “our underwater fire is not disturbed by it”, so as hot and gruesome as you thought factories were back in the days, these ones would be worse than Finnish saunas. I am allowed to make this joke! But they can work through it; after all, what are a few dead overworked swimmers for the march of progress and endless profits?
Electricity is the new hurdle. As much as you wish the water is pure, it isn’t. It has ions in it that allow currents to move which is why storing electricity in water is hard, as it will start letting it flow no matter what you want. This is why you don’t mix water and electronics! They would have a hard time generating electricity as anything that stores it is immediately discharged. Transferring it has the same issue. So in general, electricity is just not going to work. Unless we once again magic it away somehow. Anne style!
As you can see, there are issues every step of the way due to water being a bitch. But for a story and world, we can make up any reasons we want as to why it works anyway. I recommend putting some thought into why they managed to get past these huge hurdles. Maybe they have some electric crystals that they can mine and are easily charged but unwilling to discharge into water! I don’t know, make it up! Have fun!
Making aquatic civilisations
So for this, Anne and I will take one each. I do scifi, she does Fantasy because I suck at fantasy. So off I go first!
Scifi
Actually let’s do this in my setting! I have a half defined aquatic species already but they ain’t fleshed out. So Stellima it is! Polypedoids was their name, probably gonna change the name after this. Actually, let’s do it right now! Kirrna, yes I like that, Slight remaking of Cirrina which is an order of octopi. I am a bloody genius. FYI that is a simple way to get names that sound familiar but with enough changing you can easily make it anything but obvious. Latin and Greek are big faves of mine 😀 Sometimes Japanese too!
But as it is a space opera setting, I cannot do a rogue planet no matter how cool it is, not super earth as they gotta be able to get to SPACE! So ordinary earth it is where land was colonised but… just continued being stupid. Still a lot of work for them to get out of the sea into space.
For their body, I am imagining they have tentacles and I mean a lot of them. A dozen below the waist and the ones from the shoulders are about six on each side. So given this, there is no way in Hanne (Hehehehehe) that they are going to be fast swimmers and they don’t need to. In their early evolution they relied on camouflage to get close and kill over speed. Similar to how you humans relied on endurance over speed. Later they started domestication and such early civilisation using stones and other lifeforms was on its way. But the Kirrna still has to solve the issue of metallurgy and electricity as steps toward space flight so how did they do it?
Well, here comes some more of my pre-existing worldbuilding, Rule #5: Re-usage is better than adding new cogs. Read it and my other one on cogs.I have nentroplasma, which is a big thing that I will not dive too much into here. Anyway, the big thing about it is that this entire subatomic system can modify atoms and their chemical properties and abilities. Quite fundamentally so where the derived atom is entirely unrecognisable in properties from the original. These materials have a tendency to accumulate far far away in the outer parts of a solar system due to interactions with the sunlight over long stretches of time. And at the beginning of the system's formation, this happened as per usual. But during the later part of their planet's formation, a red dwarf, white dwarf, some big ass heavy star flew by and disrupted the outer parts. This caused a massive rain of asteroids and meteors heading toward the planets in their infancy and then rain down hell. Fortunately, there was no life, barely any water on their world which would become more of an ocean world than a land world.
These nentrified materials would later by the Kirrna be used to start metallurgy through different means than you humans, and same with their electrification. And with this, their early models for atoms and such were extremely different from most other worlds, until they figured out things more. In some ways, they learned more about the world thanks to this fluke earlier. With all this help, they could go through all technologies needed until a group finally said, “Let’s go to space,” and thus it happened. The rest is, as they say, history.
Fantasy
(Anne:) As Vivian referenced a few times above, you might want a little magic to get your aquatic civilization going, and that means it’s my area of expertise! Vivian may be a genius at scifi, but zhi falls flat when magic gets involved. Anyway, let’s try to imagine what an underwater civilization would look like in a fantasy world!
Drawing on what Vivian said above, we’re going to have a species of people, merpeople, who aren’t like the typical merpeople. Well, they’re sort of like them. But they’re not half-human, half-fish. They’re all the same creature, so there’s no distinction between parts (I never understood how mermaids could breathe underwater since their lungs are from the human half, but I guess there’s some hand-waving going on there). Our people are adapted to the depths, and look more like dolphins (yay dolphins, after all, we want the potential for war crimes!). However, very importantly, they have prehensile appendages in the form of finned arms. While the arms do create drag, they help the merpeople scavenge for food and, importantly, use weapons that make it easier to hunt. Why did evolution do something so strange as give them arms? Well, I’m glad you asked!
You see, a thousand years ago, a species from the land managed to get down to the depths using magic to breathe underwater. They saw the intelligence of the merpeople, but were versed in Vivian’s logic above and knew that the merpeople could never reach their true potential as they were. When the strangers began talking about all of the things that had been accomplished on land, the merpeople grew jealous and despaired of ever creating a civilization that lasted longer than the oral tradition. So the strangers, moved by their plight, sacrificed the last of their magic to grant the merpeople two boons: arms that would allow them to manipulate objects but not slow them down too much, and the knowledge of how to make seafire, a substance that warms the immediate area only and can be reversed to cool it as well (neatly getting around several of the problems Vivian talked about). The strangers drowned, but the merpeople rejoiced, and immediately got to work recreating the world that the strangers talked about.
There were stumbling blocks, of course, and in order to create a civilization anywhere near ours on Earth, a lot of infrastructure needed to be in place. Luckily, their environment is stable, and there are plenty of large filter feeders to hunt (made easier with arms that allow for weapons!). There may have been a few wars and genocides and other atrocities along the way, but who are humans to judge?
But now, a thousand years later, when stories of the world above water form the religion and mythology, one merperson has discovered something new: an underwater source of magic! But unlike the mythological magic that allowed land creatures to breathe underwater (what even are land creatures, kids today ask), this magic allowed energy to be transferred from one place to another–aka electricity! But magic electricity! Far superior. This discovery has supercharged a revolution in society, creating a rift between those who value the old ways and the slow path set forth by the strangers, and those who want to seize the opportunity to do things those ancients never even dreamed of. Thus begins the story!
(Vivian:) Thanks for this wonderful example of ideas in fantasy! As many can see, there are similarities and similar solutions between us, but that is because those hard limits are so damn hard to get past.
Summa Summarum
In the end, it was the ocean all along! Jokes aside, as you can see, aquatic civilisations are tantalising, but for more advanced ones, they are harder to justify due to how water differs from air. For Roman or even mediaeval tech societies that use stone instead of metal, you can get by easily. Hey fantasy fans, do a Tolkeinesque high fantasy set in a mediaeval Europe styled aquatic setting! No credit needed! For hard scifi, this is still where you get stuck and likely cannot go past without some benevolent terrestrial benefactor coming into the picture which of course is a fine thing to make! But without it, some cool soft scifi materials and stuff are likely needed to get past these hurdles and future ones.
This is all for this time, and as usual, have fun and explore all the crazy you can imagine!
Want to dive into a discussion about Stellima or the art of writing on Discord? We’d love to have you! And if you have any topics you struggle with or that you would like to suggest for a future blogpost, we’re open to suggestions!
Interested in supporting our work? Join our Patreon and become a part of Stellima as a citizen of Mjatreonn! Or would you like to give us some caffeine to fuel our writing? Consider buying us a coffee at Ko-fi! Every contribution inspires our creativity and keeps us going. Thank you for your support!
Copyright ©️ 2023 Vivian Sayan. Original ideas belong to the respective authors. Generic concepts such as aquatic societies, ideas about settings, and ideas to solve the hurdles are copyrighted under Creative Commons with attribution, and any derivatives must also be Creative Commons. However, specific ideas such as nentro- system, nentrified the material type, Kirrna the species, and all language or exact phrasing are individually copyrighted by the respective authors. Contact them for information on usage and questions if uncertain what falls under Creative Commons. We’re almost always happy to give permission. Please contact the authors through this website’s contact page.
We at Stellima value human creativity but are exploring ways AI can be ethically used. Please read our policy on AI and know that every word in the blog is written and edited by humans or aliens.
