Seems as though many of those in the upper river are Canadians. Also noted in the article is that upriver escapement hasn't met U.S.-Canadian treaty numbers for most of the recent years.

And then take a close look at the following info extracted from the article:

"But in the middle 1970s many people in the lower river shifted to a technique called drift netting, where a net stretches out from a boat drifting down the river. In 1960, there were 46 drift nets on the Yukon. By 1975 that number shot up to 314, a nearly sevenfold increase. One year later, there were 700 permits that allowed drift netting in the lower river, as Fish and Game established a “limited entry” commercial fishery."

One can point at the trawl fishery all one wants to but they aren't the only problem. And I wonder how many of those 700 permits are held by "Natives."