It never occurred to me before, but now that you mention it, it makes a lot of sense that the repeat spawning life history does a lot to explain how hatchery steelhead programs are so much less productive than salmon programs. I have never heard of hatcheries releasing spawned steelhead to migrate back out to sea, potentially to return and spawn again. I wonder why that is? If you are trying to replenish a natural resource with artificial production, it stands to reason you'll get better outcomes if you mimic, to the greatest extent possible, a natural life history for the species in question. I would imagine an adult steelhead is much more likely to survive another year at sea than a smolt is to survive its first year at sea. By that rationale, repeat spawners probably find their way back to the gravel at a much higher rate than smolts spending their first year(s) at sea.

I don't think gillnetting is a leading cause of the decline, but I do wonder how many rebrights and repeat spawners die trying to migrate back and forth....