We'll just disagree on this one Keith. Generally speaking, hatchery steelhead don't do anything positive for wild steelhead. In the case of western WA wild winter steelhead, very few hatchery steelhead spawn with wild steelhead. Genetic introgression does occur, but not to a very high degree, and certainly not enough to be a major factor limiting wild steelhead population abundance. Yes, there are cases where adding or removing hatchery steelhead is correlated with negative or positive changes in wild steelhead abundance. In the majority of those cases, the same identical swings in wild steelhead abundance also occurred in river systems where hatchery steelhead have always been absent. We need to be careful about asserting causation with correlation because it does not always hold.

The proximate cause of declining steelhead populations is the very significant reduction in marine survival dating to the early 1990s. Which happens to inversely correlate with the increasing abundance of pinipeds in WA waters, especially Puget Sound. And fairly recently this correlation has been shown to be one of the causes for decline. Other factors appear to be things like ocean upwelling (the blob of 2015) and PDO. The longer term proximate cause of declining wild steelhead populations has been freshwater habitat degradation. When you account for the swings in wild steelhead abundance in rivers that don't have hatchery steelhead, the stocking of hatchery steelhead moves quite a ways down the list of factors affecting wild steelhead population abundance.