This also has significant implications for hatchery management. If steelhead juveniles are fed too much in the hatchery, they become resident rainbow trout upon release. They lose the instinct to migrate to the ocean, so they never leave the watershed (i.e., fat, dumb, and happy).

And, if we’re also raising and releasing fall Chinook (sub-yearings) in the same watershed (which is not unusual), those hatchery resident rainbow trout will consume large numbers of those Chinook subs. So hatchery managers need to raise and release their steelhead production to ensure they become steelhead, not resident rainbow trout. It’s an issue of size-at-release, and release timing.