shrimp/fish farming?

I've always had an idea of shrimp/fish farming on my land to supplement my income. I'm sure it's a silly idea
Has anyone thought of such a thing out there?
I figure I can't always sell vegetables at the farmers markets to make money.

I once lived where there was a crayfish farm down the road.  Often we would go there to buy crawdads buy the pound.  They also sold packets of seasonings like crab boil to cook the crawdads in.

I have also seen places where folks charged people to let them fish their pond.  I think the fish caught were sold by the pound.  Some were called "Catfish Farms."

Since shrimp is a saltwater species that might be a little more difficult.  

This is not dumb. It has been done.
There is an inland outdoor fish farm that I culdn't find online today. The story was something like this…
Man wants to get back to the earth, buys land to farm, or market garden. He fought his soggy land, trying to farm it. He was inspired and realized that the problem is the solution. He made his soggy land into a large pond and started fish farming. I think he became successful at it too.
Hopefully somebody else remembers the farm name.

A non permie article titled: Replacing Farms With Fish Farms: The Odd Solution To Both Hunger And Climate Change, also not permie.
https://www.fastcompany.com/3068608/replacing-farms-with-fish-farms-the-odd-solution-to-both-hunger-and-cli

And what appears to me to be a well thought out article, or chapter: 9 must-know things about starting a fish farming small business.
https://entrepreneurshandbook.co/9-must-know-things-about-starting-a-fish-farming-small-business-ec93b925f940
Good luck!

It is not a silly idea.
There are people who make a good living raising aquatic species on small farms with small amounts of water. Many of them are raising unusual species to supply specific niche markets.
It is difficult for a small timer to compete with large well funded operations that raise the standard commercial aquatic species.
A small niche market can provide a farmer with a good income if that farmer is the only supplier.  

Commercial marine shrimp farming began in the 1970s,  ...  Virtually all farmed shrimp are of the family Penaeidae, and just two species – Litopenaeus vannamei (Pacific white shrimp) and Penaeus monodon (giant tiger prawn) – account for roughly 80% of all farmed shrimp.


https://en.wikipedia.org/wiki/Shrimp_farming

Guys thank you so much. This is inspiring. Now I have to find ways to start it up with close to nothing.

I know of three fish farms near my village. Each of them are raising trout. It's what works for our climate. One sells meat at the farmer's market. One offers fishing opportunities, and fillets the fish. The other focuses (I think) on tourism, (catch and release).

Freshwater shrimp live in the creeks around here... They are small, but if you raised enough of them well enough I'm sure that there would be some kind of market.

I still can't find any info on that fish farm I mentioned earlier. In searching again I did find this promo for fish farming in Zambia. Why Zambia came up in my google search? Dunno... It may be a bit simplistic in presentation, but perhaps you can glean some stuff from it.

http://www.fao.org/docrep/field/003/ac079e/ac079e00.htm

And a Geoff Lofton you tube presentation on one of his fish ponds.

https://www.youtube.com/watch?v=e2B2Nyji7v0

Hey, if JGeoff does it, how can it be bad?

There was an inland shrimp farm between Austin and San Antonio. I did a search to post a link. Its closed and now manufactures cardboard boxes.

I found another but it is bayside. It brings in water from the ocean.