Our king salmon population crash was started by Asian fishing fleets in the high seas, since they normally harvested kings by the high 100,000s. One year Japan got a record 1 million-plus kings. A few years after that, kings began failing in western Alaska and subsistence fishing was curtailed in the Yukon and Kuskokwim rivers. Even commercial fishing for kings ended. But Japan continued taking very high numbers of king in the high seas, until the USA and Russia forced Japan to limit chinook salmon fishing and created 200-mile exclusive fishing zones. This was in the 80s. However there are still 1,000s of fishing vessels in the high seas from Pacific Rim nations, both legal and pirate, and who knows what they are catching. Legal vessels that target certain fish species have to throw untargeted species overboard, such as salmon. I'm sure rogue fishing vessels don't give a hoot about what they catch.