Not all broodstock programs result in hatchery workers killing natives. In the Chinook broodstock program on the Dungeness, for instance, the natives are allowed to pass upriver and spawn on their own. Hatchery workers then hike the river and count and identify redds. They pick a few redds to get eggs from, and they go out in the spring to do this... the parents are long gone.

They have a gizmo that they insert one end into the gravel, it gently pumps air and water into the redd, and floats some of the eggs, which are collected in a bag. They only take some of the eggs from various redds, and I believe they are raised seperately.

my $.02

-N.