An old mate of mine once had a property at Narrabri a place in NSW well known for pig shooting,and on this farm he had two dams or he called them dams,they looked more like giant puddles that had been dug out with an excavator.Anyway he was looking for ways to make easy profit and he came up with an idea that if he caught a few yabbies/red claw and stuck them in his dam they would breed and he would become rich.And it worked(at least the breeding part).Within two years his dams were full of crayfish,and then it rained(bugger).He showed me a map of the outlay of the property about a year before and I asked what all these little markings were,and he said low ground,and I said,"you mean swamp!"He said but it has'nt flooded up there for over 20 years or something like that.Anyway there was plenty of yabbies down stream that year.But if you know anyone with a private water reserve,even an old above ground pool with a pump,maybe within a few years you might be selling them to the fisheries.