Mowsley,

Yes. An adult salmon or steelhead in freshwater strikes for reasons other than hunger because they are not actively feeding to sustain themselves, although steelhead feed opportunistically at times. So they strike because of a latent feeding response (hey, it's all they've done during their time spent in the ocean) or aggression. Except when steelhead are engaged in opportunistic feeding on loose salmon eggs or insects, it's impossible to know whether a fish strikes due to its feeding response or aggression. In any case you can be sure it isn't due to hunger.

Sg