Feel for ya' Tigermullet!
I only kill what I'm going to eat.
Always make an effort to despatch as quickly as possible.
To be honest I personally don't like killing big fish, but then I prefer not to eat the big fellas either. Any jew over say 10 kg will go back if I think it will survive, otherwise it will get eaten.
Fortunately I don't catch many mulloway over 10kg, which suits me just fine.
Plenty of rays and sharks over that size though. Couldn't kill them with an axe, they swim away almost totally unaffected, chuckling to themselves, "ah, silly old bugger, gave him a workout!"
Cheers!