I understand your logic and applaud your care and consideration, but you are aware that we can kill and eat them? Not trying to be a smart-aleck, but if I choose to lip a bass and keep it out of the water for 90 seconds to weigh and take a selfie, it's got a hella better chance than any walleye I catch.
I'm not knocking what you choose to do in any way, I'm merely responding to your question. And as for the "bath of fungi, bacteria, parasites, and viruses" they are living in the same water that I ski, swim, and drink and they are much better suited to surviving it than I am. I guess what I'm saying is I just don't feel it's quite a dangerous for them as you feel it is. God made us a hardy lot and he is infallible.
Again, you are living your life according to your beliefs and I support it. My wife loves it when I send her the big fish selfies. She keeps a slideshow of them running on her work computer. I'll be sending more.