Cerulean Seas: How does a Merfolk society actually work?

[EisenKreutzer]

I am reading through Cerulean Seas, and have run into a bit of a problem.
I have no idea how an aquatic society would work practically.
What would the architecture be like under the ocean? What requirements do a society of merfolk have that need to be met by their architecture? Which requirements does being hundreds of feet below the ocean pose for merfolk architects?

On the topic of architecture, how do you design a fortress or castle in a world where anyone can just swim over a wall? How do you defend a city or town?

What do people eat in an oceanic society? Fish and vegetables, obviously, but how do they prepare their food in an environment without fire? How is food preserved?
How do you raise livestock when fences are useless?

I'm sure there are tons of more questions I need to ask that haven't occured to me yet.

[VoxRationis]

The fortress is easy: 3D walls. You have a reef or rock formation with tunnels running through it. Being hundreds of feet below the water means that any material will have more crushing force around it from the ambient environment than it would on land, but the greater buoyancy of water means it will experience less stress from its own weight.

How do you prepare your food? Probably raw, when it comes down to it. Finding real heat sources is going to be very difficult underwater. Geothermal vents are an option; most are ridiculously deep in the ocean, too much so for interaction with conventional merfolk, but you could have a shallow-water vent in a volcanic region, I suppose. I mean, if you can have an above-water volcano continually erupt, you could do something similar just a few hundred feet lower. One sci-fi story I wrote a long time ago suggested concentrating sunlight like those solar ovens you can buy, but I'm not sure that would work very well; the water would reflect or absorb too much of the light.

You raise livestock with leashes; most fish can't turn back to gnaw at something around their pectoral fins. More plausibly, you have herding animals trained to hem them in, or modify the environment so that they have nowhere to go (i.e., a small, slow reef fish will not make a break out into open water, so if their "pen" is the only shelter around, the ability to leave will be irrelevant to the tendency to leave).

Tactics and battle are going to be very odd in such a setting. Ranged weapons of any sort are going to be practically useless; even modern ranged underwater weapons tend to be very short-range indeed, and most that aren't some sort of gunpowder weapon or highly advanced pneumatic device are practically melee. Swinging a weapon will be difficult in water; piercing weapons will therefore be more likely than swords, though a knife could be used in close quarters. I'd predict charging to be important, since it's the easiest way to get a good amount of kinetic energy behind a weapon. Depending on how fast and maneuverable your merfolk are, retreat may prove difficult; swimming backwards isn't easy, even for most aquatic species, and turning around in close-quarters combat is near-suicide. Tactics might therefore favor strafing attacks, wheeling back around after a pass at the enemy, or else might favor bloody melees where troops are simply committed once they are sent forth. (The difference between those modes of thought might well be cultural.)
Defending a site will almost certainly mean fighting in melee from it, so crenellations will be eschewed in favor of narrow tunnel entrances, often with T-junctions so that an invader coming down a hallway will be automatically flanked by defenders when they come to the junction.

[EisenKreutzer]

I really like the idea of 3D fortifications. The merfolk could grow coral in a sort of lattice around the settlement, with narrow tunnels leading into the populated areas. Such tunnels would be easily defended, and have the added bonus of being sharp and dangerous for more than one person to swim through.

[Everyl]

My quick advice is: don't get stuck on "the" answer to any of your questions. Think of all the different ways that real-world humans have solved your questions on dry land around the world and throughout history. Merfolk would find just as many solutions, depending on local climate, wildlife, etc.

Some merfolk are nomadic, following migrating animal populations. Depending on the season, they might hunt fish, sea birds, and/or aquatic mammals, sometimes stopping to forage for shellfish and seaweed.

Tropical merfolk might modify coral reefs to make fortresses, leaving only a handful of small entrances, possibly guarded by domesticated sea creatures. So many animals live in or move through tropical waters throughout the year that they would have to travel relatively little to hunt for food.

Other merfolk might set up a quasi-agrarian society in the shallows, tending beds of oysters or clams alongside edible kelp or other seaweed. Domesticated manatees could provide milk and/or meat, though there wouldn't be any good way to store the milk.

Pretty much all of them rely more on freshness than on preservation for their food. Cooking, drying, and salting don't really work underwater, though coastal merfolk might find it worth their while to smoke or sun-dry fish on the shore, as long as they have a dry place to store it safe from land-dwelling people and animals.

[EisenKreutzer]

The preservation of food thing is really throwing me off. As you say, you can't dry, salt or smoke food under water, so what are you left with? I suppose chemical preservation, with lye for example, could work. Another idea is to perhaps keep the food in some kind of oil? You could potentially get oil from whales, which I guess could be used to conserve food?

I'm really having problems envisioning cooking and food in an aquatic setting.

The other point, about having different cultures solve these issues in radically different waves I am definitely in agreement with. Nomadic seafolk could live in huts or tents weaved from seaweed, for example, while other cultures could build great, labyrinthine stone fortresses, or cities built in concentric rings separated by towers and walls, while more deep-sea dwelling seafolk could use volcanic caves and caverns.
I think exploiting natural terrain to build defensible settlements, like building a city in the side of a cliff or beneath an overhang, is definitely something that would be very common in the Cerulean Seas.

[VoxRationis]

Chemical preservation would be difficult—the chemicals would rapidly diffuse out and become hazardous to others before eventually diluting to the point of irrelevance.

Making tents or other shelters would be a privacy thing only, most likely; "the weather" isn't much of a factor underwater.

[EisenKreutzer]

I hadn't even thought of the weather, or lack there of. The only thing to worry about really are the currents, and they only matter if you are close enough to the shore, though they would produce wind-like currents. Some races, like the Viridian Naiads would probably just sleep in kelp forests or similiar, possibly tying themselves down or weaving small nests sort of like apes do. They do have +100 buouyancy, so they would need to tie themselves down to keep from bobbing along on the surface. :P

I suppose there is nothing wrong with just sleeping on the sea floor. Races like the Kai-Lio could definitely just do that, but I'm struggling to see the Sea Elves not having some form of permanent settlements and buildings.

[Jendekit]

I want to pitch in regarding the preservation of food.

Having run a game based off of the Cerulean Seas material, what I did was I made food preservation be something that doesn't happen underwater. Any preserved food was always traded with land-dwelling peoples that would wrap them in a form of parchment and/or cloth that was enchanted with a one-directional Gentle Repose. In layman's terms, anything wrapped up in these wraps were not subject to decomposition and was kept at the same level of freshness that it was at when it was wrapped.

Everything originating from the seas however had to be eaten fresh or it would spoil, and processing had to be done very, very fast due to sharks being attracted to the smell of blood.

[EisenKreutzer]

Yeah, it makes sense that they won't be able to preserve their food in any way. I still think theres potential in using oil, but you would need some way to store it. Perhaps having a special oil hut where the roof holds a bubble of oil and you hang the fish from the cieling to make sure it doesn't sink out of the oil bubble could work.

Alternately, you could use aqua gravis to preserve food in chemicals.

[Yora]

The only kind of underwater society I found to be remotely realistic assuming real world chemistry and physics is basically stone age hunters. Being on land is drastically different from being in water, and not only because that's what we're used to.
On land you can have chemical processes that are happening in sequences of being in the air or in a water. On land you can make fire snd you also can have heat that is confined to a single small area. That's just not possible if you're underwater all the time. There will be no metal, no pottery, and no leather. I think there wouldn't even be wood. The only material to work with are stone and soft plants. Animal teeth might also be available, but that's it. And as others mentioned, there isn't food preservation either.

However, aquatic creatures have much fewer needs. Houses are useless as you don't need to protect yourself from the sun or wind or the cold of the night or winter. You wouldn't be able to heat the place anyway. Since you can't preserve food you don't need to store it either. Doesn't really matter though, as there are no growing seasons. The only useful thing is caves to hide from large predators like sharks.

If you had aquatic humanoids developing in any way similar to humans, then paleolithic is going to be where technological progress stops.

Things look different when you have people who can survive outside of water for hours and make their home on beaches. If they have their workshops and storehouses on land, they could get almost all technology of land people,, though metal is still unlikely, given that those don't lie around on the beach. They might still sleep in the water, but that would hardly be an underwater civilization.

What I did in the end was to make my mermaids all fey who do everything with magic.

[sktarq]

The thing is there are seasons in the ocean. Phytoplankton bloods are based on the changes in sunlight and currents that occur as the sun gets higher and lower. The Bull or Giant kelp of the North American west coast is well known for growing at incredible rates (and makes a great place to pop aquatic elves) but in that rates drops off in the cooler months and in the northern part of the range the kelp dies off each year from the drop in sunlight. The great runs of herring, sardines, other smaller fish are seasonal in nature. Most of the whales found in the polar regions are mostly there for the summer when extended sunlight drives the phytoplankton to grow and divide at incredible rates which then cascades up the food chain. Currents shift in hundreds of miles over the course of the year-often more about where is the main strength of the current in a wide band but it has massive effects on local regions.

The open ocean is basically a desert or a overwhelming amount of life with little in between and where those spots are highly depends on the season.

As for "shelter" if the merfolk live in the shallows up to say 250 ft (~83 m) then surface storms could be a a pain-silt movement, the object you just put down being pushed around in an unexpected direction, etc would all be significant factors. Plus defensive against predators.

As for tools-Bone ( esp large reptile or mammal bones) and Shell would both be added to list of common materials for tool use.

As for storage-I'd actually recommend a biological one. Animals that can hibernate and store food internally but can also gorge in the good times. Perhaps a domesticated crinoid or echinoderm perhaps.