Newbee has a point here. The Torah mandates shchitah for killing animals and fowl, and the blade must be sharp for a quick cut. Prolonging the death of the lion is exactly the opposite.
I’ll also repeat my question regarding any difference between hunting and fishing for sport, as shchitah isn’t required for fish, and I think that has something to do with fish not feeling pain, but I could be wrong.
However, if the concern is our own sensitivities not being dulled, it makes sense not to recommend fishing for pleasure either.
Talking about dulling our sensitivities reminded me of the “What’s Wrong with What’sApp” thread, where I mentioned that some video clips do just that by showing other people’s embarrassing moments, even if they aren’t showing anything explicit.