Hey Bear. Might want to divert your attention from the individual fish you have been catching over all those years and try focusing on the environment they live in for a moment! From what I have seen, IMHO, is that there are other factors being the "main cause of mortality" to steelhead. Starting from conception: silt, stream bed movement, disease, funguses, starvation, assorted birds, mink, otters, seals, other countless ocean occurances, some rivers gillnets. And you think catch and release fishing is the biggest cause of mortality!! lol