i learned today that they are fed here with heat treated herring meal. That the salmon enhancement program suspect the feed to contain hormones , because they bought some feed from a farm when running out their own feed to raise young wild salmons. They observed an anormal growth spurt in a few week of using it. The wild salmons eat lot of very small crustaceans and little fishs ( they have an herring feast here in the spring) they themselves are predated a lot by seal, orcas, otters, eagles, bears and human . More they eat shrimps more they are red fleshed and .fatter( the sockeye salmon is a delicacy) Looking for more information. jean-claude