I was on a PS once, collecting chum on the 9/10 line for stock identification. The goal was to kill 100 chum and release everything else. First set or two worked. Then we got a big haul and killed a whole lot of stuff. Just too many fish to work. The seines will work when each haul has a relatively few fish.

I was also part of a beach seine test fishery to see if one could harvest male Chinook and release females. Simply didn't work; it was too hard to safely C&R the hens. Those with hands-on experience in Doc Donaldson's pond know how hard it is to handle adult salmon one at a time, safely.