Absolutely there are. Many (or most) of the people who catch fish, pour coke onto the mortal wound they just created for their own leisure and toss them back into the water to die would confidently tell you fish are incapable of experiencing pain.
I've fished. Never felt great about it. But most fish at the fresh water angler level can be caught and released without mortal wounds.
It's hard to reconcile that you'd be willing to rip an animal from the sea to kill and eat it, or just for the fun of it, but also care about the animal though to conduct some insane little ritual of pouring soft drink on the wound you created to try and help it survive.
I doubt the knowledge of consciousness, pain, or any other harm caused by hunting or fishing would dissuade most that do it regularly (in my anecdotal experience)