I'd go with the catch or release, but wouldn't hesitate to use the method OS described, if the mood hit me. I took take a be-headed/gutted Laker from Jean to the East end of Sturgeon on a high 80 degree day with zero loss of flavor. I kept it under my seat and just re-wet as needed. The canvas bag worked wonders.  I don't throw back an eater size Laker unless I'm damn sure of catching another before the day is over ;D

I wouldn't put the fish in a pack, but would Bungee Bob under a seat in canoe.