In the western United States, when something good gets discovered, it seems nothing better to do than to rush to deplete the good – gold, trees, … salmon.  Gold is mined many times at the cost of whatever lived in the area before.  Trees, centuries of age, swept away, sometimes replanted, sometimes not, always with ecological cost.  In the case of salmon, former runs of billions of salmon first suffered from overfishing, taken to extremes.  To finish off the magnificent earlier runs, primeval rivers dammed ending the prehistoric runs.  Fish hatchery to the rescue