I was a foundation member of the native freshwater group of NZ.
We had no probs.
DON"T get white bait when they are whitebait out of season.
When they get to a point where they are not "clear" and have there own id. go for it.
To protect the species, do not aim for the big ones.
Get the teenagers.
Try not to handle them with bare hands, and learn how to bag them without taking them out of water.
We used furanace in our holding bags as a preventative to skin damage, they are super prone to whitespot and velvet, so I should have said, as a preventative of those diseases.
Try to get some of their water in their stream and add to their new tank, then add aged water to top it up slowly.
They can make a real kewl display.
Watch the temps in the summer,
oh !!
what summer.
Alan