I think it may have been possible in a different system. For instance, there was another predator years ago, in another lake in the Miramichi, but it was a shallower, more simple sort of system, where they were able to eradicate with a poison, rotenone. That was effective.
The problem in this particular system in Miramichi Lake is that they apparently weren't allowed to use the poison. The attempts made through a combination of gillnetting and electrofishing in different portions basically kept the numbers down, but that agreement is now over. The young-of-the-year smallmouth bass are up again, and there's only a four-kilometre stretch with no barriers to the Main Southwest Miramichi for them to move to.