On the traps I worked on we examined every steelhead closely. Fortunately, we had scales to confirm H/W. This was before ad-clipping so you had to look at the fins. Most, raised in concrete, were obvious. We had a few, though, raised in dirt ponds, that maybe had one or two broken rays in the dorsal. You had to feel for the break. What was impressive to us was that the visual quality of the dirt-pond fish.