Bug eyed glowing savages,sounds like fun.Most of the pcb's in Salmon collect in that mushy grey stuff were the lateral line is.Tough call on Salmon when you go by skin color for example the Kings that go up the lower Puget Sound rivs are from the Kalama River fall Chinook and by the time they hit the terminal fishing areas are already dark in color.Don't know about the Great Lakes fish but it might be the same.