My thinking is "Why bother with the quasi-scientific philosophizing?" Maybe fish can feel pain, maybe they can't. You are still empowered to do your best to avoid causing those ambiguous situations. It's actually really easy to do: stop fishing.

You aren't fishing for survival or food. Your personality isn't going to disappear. You can find a hobby that is just as rewarding. You can avoid all the risk of inflicting pain and still have just as much happiness and pleasure doing something else.