Steelhead arise from the most adaptive variant of trout known- the bo. They're here because of a wide range in temperature tolerance.
But I sure agree with you about those g-ddam sea lions and the Portland micro-brew wienies who snivel over them. Those dead firs covered with cormorant crap on the Siuslaw's South bank stand as markers of their destructive invasion. It's a pretty bird, but I'm not all that fond of Caspian Terns either. Jumping through the many Obama administration hoops to qualify an individual sea lion as a pernicious threat isn't going to relieve any pressure. Sure it's mostly a human problem, but you get in trouble for killing humans, it's time to start killing rival predators. We'll burn votive candles for them or something, it's time to come to the aid of some close friends, for the present as well as the future. They can't have a future if crowded out of the present. Thanks WL.