Check with U.S. Wildlife Service for just how many have been caught as opposed to how much predation has occurred.  You should know better than to deny this truth.  Poaching rings operated throughout North America and especially in Alaska and have for decades just because of the secrecy and massive money to be made.  One operation in Alaska was based in a bar in Minnesota.  Law enforcement has the stats.  Talk to them since you have more access than I do.