I have to say, I am with Ranger on this one. If you have a use for it, by all means, kill the animal. However, what is the point then of throwing it back injured, where it is likely to die a slow death. Just because it swims away at the time, doesn't mean it survives.If someone attacks and stabs you in the stomach and then you run away, can that person think, Oh he'll be ok because he ran away? Without any medical treatment you could easily die a slow and painful death.If you don't intend to keep it, why not give a chance to live, so that the next angler that comes along may have a chance