If it can be shown that stocked summers have a negative impact on the winters then they could be stopped. Since Skamania fish show a much higher ability to establish "wild" populations, and we know that their juveniles would compete with winter juveniles, then you could an impact requiring action. That will probably be on the agenda once winter-run hatchery programs are sorted out.

In Oregon, they laddered a falls that summers made it over but winters didn't. Result was a decline in summers. When they stopped passing winters, the summers rebounded.