Back in the 80s, the outfit I worked for pretty much went exclusively over to seines instead of gill nets because of the high rate of incidental catch of gamefish. Commercial fishermen in ND are generally targeting goldeye with gill nets. Seriously. :;:huh
Not only does NDGF use gillnets for their surveys, but so do some researchers. I helped a putz of a guy from Idaho back in the 90s with his gillnets up around Lewis and Clark State Park. They were targeting walleyes and pike to get an estimate of their predation on paddlefish young. I'm guessing that guy is still an idiot that can't catch a fish with a gillnet.
Anyway, I too would contact NDGF. Obviously, they would know if anyone has a permit to use it in that area.