I read through the study and it states that the largest source of predation is most often squawfish but that it does vary a bit by season. It also points out that bass and walleye predation are non-neglible. HOWEVER, it's s study only on predation, it doesn't talk about the other effects up and down the food web of having these non-native species in our waters.

In general, the history of non-native species introductions is terrible in many areas and for many species. I just can't see a good justification for wanting to keep these fish around.