I belong to a enhancement group and we do the same thing, we take native stock from that system, spawn them and then raise them in incubators and release them when they are ready to go. What this does is build the stock that is native to that river back up and once it is at a self sustainable level we will no longer have to do this because they will be able to accomplish this on there own. These native brood stock programs have been very successful and I would encourage it to continue and for more people to get involved, it works.
Peace Superfly