I realy dont think it's meant so much for all fish mentioned as it is for Salmon, not sure why bows aren't listed, maybe typos ? Culling Calico Bass could be fun, lol, which of the 25 to keep.
I think it's impossible to weigh in a Salmon and have it still alive by the time he is put back in the lake.
Killing a Salmon is not neccesary, just put him in the cooler on ice, he'll be dead in a minute.
I do know people that kill and bleed them first, supposed to enhance the taste ??? Myself, I prefer lobster.
All in all I think the rule is horse---, many times a fish is returned to the lake later for one reason or another, Salmon or otherwise. Maybe you only get one Crappie, how you going to have a fish fry with one, might as well let it go when you get back to the dock.
I think it is a "new' rule, maybe quoted wrong by the writer of the rule book or missed in the editing/proof reading ? Tbe old rule said you can't leave the lake with a "live" fish on the boat, or something like that.