I am really curious about the oak flowers, we call them squigglies, poisoning the fish. I have more than my share of Live Oaks and their trash but have never had a problem with the fish. My pond is tiny and I scoop out once or twice a week during the messy season. I can see the bottom of the pond is a mess with leaves and one of these days I will get to it. I've never netted or screened the tops of my ponds, they have always been right under windows so we could easily look at them and DH would have a fit if he couldn't see the fish.
Each year the oak leaf drop seems to get worse and local landscapers say they have never seen anything like this year. We are blowing our deck at least twice a day and I am afraid much of that goes into the pond.
I have seen the fish eat the pollen, you see them scooping it up during the yellow season. I wonder if too much of that could be harmful.