Sam, no where did I imply that high sea drift nets are used in the Fraser. To imply you know more than me about the subject is silly. I am 56, university educated, and read widely on fishing related subjects, so I hope I know something.
Those are huge long nets drifting in the ocean. The Japanese fishermen are notorious for using them. When lost adrift in the ocean unattended, these drift nets become graveyards for fish, dophin, sharks, turtles, and what have you. They sink when overload with fish, only to flow up again when the dead fish rot and disintegrate from the net. This process is repeated doing untold damage. Yes, high-sea fishing treaties have eliminated these nets.
In regards to the Fraser, much smaller drift nets are used. But in relation to the river width & depth, its killing power to fish in the river is relatively much more potent than in the high seas where fish are much more dispersed. They should not be used in the Chilliwack area due to the fast, narrow and shallow condition of the flow. Escapement is minimal with these nets. BBers can tell just from their fishing result whether illegal poachings by drift nets have occurred down stream of them - just a plain vacuum of fish after drift nets have done their job.