as far south as you are probably no chance of sampling fish by way of ice fishing right?
If you have YP in this pond they may bite on a live bait presented slow on the bottom just like they do through the ice. That would help you decide if you have a few YP left. I'm not sure how else to sample what 'small fish' are in this pond since I'm not sure if fish would go in traps at this time of year.

But again, SFS would be able to outlast any panfish (their mouth size isn't very big) and would be more subject to predation if they were overwhelmed with predator numbers (say 10-15 big hungry YP to every 10 minnows)