It's easy to find examples of humans introducing non-native species to solve some problem (e.g. for food, to control the population of a pest), but later regretting it as the introduced species upsets the ecosystem.
Are there any examples of this going as expected?
I guess, since I'm really interested in how well humans can predict this sort of thing, what I'm looking for is examples of a situation where there were no unintended consequences. (Rather than beneficial, but unintended, consequences).