I bet the birds at my place get a fair amount of the dog's food. I seems to be something I have to accept, but I would have a hard time with the GBH getting the fish. That's a part of the food chain that doesn't benefit you.
Would feeding in deeper water help or be possible?
Maybe a floating ring to contain the feed with some netting of some sort to cage off the feeding area, kind of like a teepee over the water from the feeder to the floating ring.