What about Aquaponics?
Aquaponics is combining Aquaculture (farming fish in tanks) and Hydroponics (growing vegetables and plants suspended in an inert medium with their roots in a mineral rich nutrient solution.) whereby the plants feed off the waste produced by the fish in a recirculating environment.

I don’t know a lot about aquaponics so any contributions would be appreciated.
Tip!  Did you know? Challenger Institute of Technology runs short introductory courses on Aquaponics
at Fremantle for a modest fee.