Throwing fish on the ice/snow
Dogfish are opportunistic scavengers / predators that eat crayfish, shad, shiners etc. They help keep everything in check. If there is any fish that should be removed it should be carp, they are not indigenous to America, hurt our waterways, and don't belong here.
I stumbled onto a few of your other posts on here the other day and have to tell you, you are a good kid. I bet your father is proud.
There is no question that you have a passion for the outdoors and represent the future generation of ethical fishermen and hunters. If other kids shared half of your enthusiasm for the outdoors, there would be a lot less trouble in the world, and a lot more kids out in God's country getting after the Walleyes and Whitetails. Keep on doing what you're doing, I think it is just awesome!
As for this thread, kind of falls under the don't pick a spec out of your neighbors eye when you have a plank in your own eye.
Nice buck you got this year by the way - bet that made your year!
The OP's point is well intended I'm sure, I understand, but why stop there if you are concerned? How about barbless hooks? Don't bring fish out of water that is too deep, don't fish for Bass when the water temp. is above 76*F (they don't always make it due to low oxygen levels), don't use treble hooks, the list could be endless.
I fish more than most, and release more than most, and I can tell you, I don't get too worked up if a fish touches the ice. If Gills are over 8" they go back, If Walleyes are over 19" they go back, LM and SM Bass also go back... If a fish touches the ice, I'll still get a good nights sleep.
I think we all do what we can - but at the end of the day, there are an endless amount of things you could be concerned about. If you are that worried about the welfare of an iced fish, probably best to stay home. No matter what you do, the fish is worse for wear when your done with them no matter how you treat them...