I have a world which is (nearly) a single-biome planet; it is mostly covered in shallow, ice-choked seas. There are few continents, but many archipelagos. Think northern Canada or Alaska as this planet's tropics.

Iceworld was not always this way. It used to be much warmer. In part to give somber historical depth, but also I needed to have land animals evolve. ;D

Here's my problem. I am not sure there is enough food available to support a human civilization. We have the following sources:

  • The sea is rich. Coastal areas thrive on hunters --- think seal- or walrus-like creatures -- which feed in the sea, then retreat inland to avoid the hotly (ha!) competitive environment of the coast. Smaller secondary ecosystems live off of this resource migration.

  • There is migration of birds and animals when feasible from the tropics north- and southward. Plant life shows up in the tropics in the summer, creatures eat it, then the creatures disperse.

  • Some kind of algae or lichen can grow on the open ice even at higher latitudes, supporting grazing and predation.

Even with all this, I'm not sure there's enough sustenance for to support a civilization. I want the main action to be in the bleak, bitter northern areas, not the soft tropics. The need is to support cities of at least 10,000 souls.

So, the actual question: How can I maximize the biomass in a high-arctic archipelago environment?

  • $\begingroup$ The sea looks like the best option. Migratory birds are not likely to survive for months without food, and rich lichen also doesn't look realistic. $\endgroup$
    – Alexander
    Commented Sep 20, 2017 at 22:03

6 Answers 6


If you want your world to be earthlike you will have to go with the Inuit-type idea. I worry that hunting and fishing will not sustain a fixed population of 10,000.

A more exotic idea would be to farm. The sea floor.

antarctic sponges from http://www.antarctica.gov.au/about-antarctica/wildlife/animals/sponges

Apparently the cold, still dark is a good place for invertebrates. It is still unclear what they are eating. Chemosynthetic autotrophs from deeper? Ancient scum from the bottom of old ice? But they are down there and they get big.


At 230 feet, the limit of our dives, the diversity is greatest. We see gorgonian sea fans, shellfish, soft corals, sponges, small fishes—the colors and exuberance are reminiscent of tropical coral reefs. The fixed invertebrates in particular are enormous. Well adapted to a stable environment, these plantlike animals grow slowly but, it appears, without limit—unless something disturbs them

So: your society could have farms of delectable sponges, tunicates and sea cucumbers that they harvest through the ice, sight unseen from the sea floor. The waste of 10,000 humans is delicious fodder for these subsurface farms. And there are other things down there in the dark that sometimes come up with the harvest...

  • 1
    $\begingroup$ You give me a civilization that voluntarily eats sea cucumbers. How could I not accept this as my answer? ;D $\endgroup$
    – akaioi
    Commented Oct 31, 2017 at 22:21

If it's ice down to the equator, it's going to be awfully solid from around 35 degrees poleward.

You can have an entire ecology that is dependent on the sea, but it will require that the seas be open for a reasonable part of the year. See the upwellings in the northern oceans, and around antarctica.

So now, you need to get ice on land, but open oceans.

Postulate a planet with less insolation than Earth, but a larger green house effect. (At times of very high CO2 levels Earth had palm trees in the high arctic, but only marginally warmer equatorial regions.)

Add a slightly thicker atmosphere, which would hold more water vapour which enhances heat transfer poleward. (Side effect: cloudier skies)

So now you have a cooler world (further out) that is more evenly heated (thicker atmosphere) and more precipitation (more water vapour) This gives more snowfall on land. If what land areas there are are tall (lots of vulcanism -- which in turn keeps the CO2 high) then the land areas will be heavily glaciated.

Glaciar areas are reflective and stay cold. Seas are dark and stay warm -- at least liquid.

Colder sea temps will decrease evaporation. May not be consistent. You would never have a hurricane. Postulate more heat transfer by ocean currents. This can give 'hot spots' where agriculture on land is possible.

A crust/mantle rich in Potassium 40 would give a source of heat internal to the planet, as well as making it more volcanic.

Option: Equivalent of Norway: Forests, but not a long enough growing season for agriculture.

Option: Small islands would share in the heat of the ocean. Possible grazing. See Shetlands and Falkland islands for examples.

Remember: A world is a big place. There is room for a bunch of different biomes. One of the downsides of many SF worlds is their uniformity. From the one example we have (Earth) real inhabitable worlds have more variety.

That said, what we know of Venus is pretty uniform; Mars has some variation, but not huge amounts, and the moons of the gas giants have all sorts of weird geology, but not much range in climate.

I posit that a huge amount of the variation in earth is due to water being able to exist in all three states.

  • $\begingroup$ Geothermal or tidal warming could possibly account for the seas being warm enough to support life that can then be harvested from the surface, but it would be a very strange ecology. $\endgroup$
    – Joe Bloggs
    Commented Sep 22, 2017 at 6:50

Some possibilities:

  1. Just because its cold, doesn't mean shorter days. The tundra-steppe habitat of Ice Age Europe was very productive, with big herds of megafauna (horses, bison, giant deer, mammoths, woolly rhinos, etc). The temperature was lower than today, which meant spring started a bit later, as plants need a minimum temperature to germinate. But the number of hours of sunshine was exactly the same as today, so there was still a hugely productive landscape, capable of producing a large biomass. And since it was too cold for trees, that biomass is not tonnes of inedible wood + few grazing animals, it is lots of grass & lichen + tonnes of grazing animals.
  2. Migratory fish bring nutrients into the system from elsewhere. Have a series of annual spawning events - trout, salmon, sturgeon, eulachon - where tons of protein and fat in the form of fish arrives in the rivers and lakes. The various fish spawning events enabled some cultures of the Pacific Northwest of America to have a far more settled lifestyle than elsewhere and dedicate lots and lots of time to art, religious ceremonies and other activities which 'resource poor' cultures can only do in a limited way.
  3. Hot springs. A source of heat for your city in the deepest winter. And a refuge for animals - much as the hot springs are in Yellowstone National Park, where the altitude makes for bitterly cold winters.

The inuit people have lived under similar conditions for hundreds of years. They are hunters and herders of caribou/reindeer.

I think you'll need to introduce a short summer because otherwise why would the animals migrate there?

The biggest problem is having permanent settlements. Herding/hunting means nomadic life at least part of the year.

You can introduce limited agriculture in greenhouses or make the settlements semi-permanent.

  • $\begingroup$ Hmm ... this might be my challenge, to create a civilization which can do well enough from hunting/herding/fishing to have permanent settlements. It's darn cold, so at least they'll have some good food storage options! $\endgroup$
    – akaioi
    Commented Sep 21, 2017 at 0:11
  • $\begingroup$ Look at Mongolia for example. A significant portion of the people are still nomadic but they obviously they have permanent settlements. The herders leave in the spring with their animals, and return in the winter so the population swells. You can have a similar setup - the nomadic people have to leave a sacrifice to the temple(s) when they return to the city and that is used to sustain the ruling elite. A tax in a way. $\endgroup$
    – ventsyv
    Commented Sep 21, 2017 at 13:40

How about a few volcanic hot sea vents on the sea bed that provide a lot of very hot water which disperses to produce areas a few tens or hundreds of miles across where the conditions are a little warmer and life congregates around these warm oasis? The warm zones can be as big or small as you want depending on the size of the vents.


Yes. Of course, it depends on if the humans arrived from somewhere else. If they didn't, then they would have figured out a way to do it, like fishing. If not, this means that they could have brought some special yeast that grows really fast, and almost anywhere(But only in a place with a special requirement. Don't want it getting loose). If there's a collapse of civilization for them, they could also fish. Since this planet used to have a lot more land, there'd be a lot of free continental shelf space. That means that there would be a lot of sunlight available in these particular spots, which means lots of plants can grow, which means fish numbers can boom, etc.

In the end, fish are plentiful, and you can sustain civilizations with them.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .