In the back of my mind I've wondered how many of the fish I let go survive and how catch and release mortality affects fish populations. Worries that i was killing too many bluegill I caught on bait caused me to give up the pratice except when I am going to keep them.
I read an article in a musky fishing magazine that essentially said that muskies deeply hooked on live bait were going to die because of tears in the stomach or esophagus, I've forgotten which, so it doesn't matter whether you cut the line or remove the hook.