I'm pretty sure there is no boom in Heron or any other bird populations so I wouldn't be blaming them on the demise of our fisheries. Harbour seals and Sea Lions may be another matter. I have seen seals 20 miles upstream from tidewater chasing steelhead, but I don't know if this historically normal or an act of desperation.

Hatcheries can't control what happens to the fish once they're at sea. They may very well be overpopulating and overstraining the viable habitat that still exists. I was reading that some of those WA hatchery fish caught by anglers cost over $1000 each to produce.