I'm designing a city built to take advantage of valuable mineral deposits in a large polar desert. The city is built around a Yellowstone-esque region of hot springs and geysers, where underground ice is melted by magma close to the surface. Water is easy; food is less so.

  • Could chemosynthetic bacteria in hot springs produce energy that a human population could use?
  • How would humans exploit that energy - directly eating the bacteria, or using microbivores as an intermediate step?
  • If humans are eating the bacteria directly, what kind of preparation would they need?

I'll also be implementing other food sources, like rooftop gardens and trading for food, but I want to have a broad range of food for this city.

  • 1
    $\begingroup$ IIRC you may have a problem with cyanide and similar substances produced by chemosynthetic bacteria. $\endgroup$ Oct 24, 2016 at 21:05

2 Answers 2


The best food system would have the lowest trophic level. That is, something that gets its energy from the sun is trophic level 1. So eating beans puts you at trophic level 2. That is low, and that is good.

The hot springs bacteria would represent trophic level 1 in your scheme. I am not aware of any good ways to feed bacteria to humans, so we'll have to introduce an intermediary species.

A good candidate would be mollusks, many of which are both filter feeders and edible. Scallops, clams, mussels, and oysters, you could have them filter the bacteria rich waters and then eat them. Obviously this would constitute a problem if the hot springs waters are too hot, but I'm going to ignore that as an engineering challenge.

Another candidate, for a more varied diet, would be to grow tuna crabs. These tiny crabs are one of the most common micronekton in the pacific, and prolific and efficient eaters of plankton. They could be fed to a variety of farmed fish for a perhaps more palatable diet. Alternately, you could depend on zooplankton to eat the bacteria, and then use shrimp to eat the zooplankton and be people food.

Note, this all-seafood diet would not be particularly good for the body, and it would have to be balanced out with some other things, but I believe you have accounted for that in your post.

  • $\begingroup$ Wonderful stuff, thank you! I'm now picturing 'fields' consisting of long, shallow channels fed from a single hot spring, allowing the water to cool as it flows downhill, with mollusks of various sorts feeding on the bacteria in the water as it flows over them. Exactly what I was trying to figure out, thanks again! $\endgroup$
    – Werrf
    Oct 24, 2016 at 20:50
  • $\begingroup$ Fungi and algae might also be suitable intermediates. $\endgroup$
    – JDługosz
    Oct 25, 2016 at 4:35
  • $\begingroup$ @Werrf yea, it needs a basin to stay hot, so the population of chemos can live there; then a small portion is overflowed to a cooler area where human-compatible lifeforms eat the bacteria. I suppose you can have different temperature zones to match the niche of each domesticated species from tropical down to arctic. $\endgroup$
    – JDługosz
    Oct 25, 2016 at 4:39

A closest real-life situation I know is a Mono Lake basin. It was not Yellowstone-like thermal, but fairly hot (some say, it it the most tectonically active area today). It supported a humongous population of flies and brine shrimp, large enough for local Kutzadika people to not only sustain themselves, but to trade with surrounging tribes.

  • $\begingroup$ Very interesting! I'll look into that lake. Did the locals eat the flies and shrimp directly, or did those support another level of live that the locals ate? $\endgroup$
    – Werrf
    Oct 25, 2016 at 13:18

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