Hello all. I believe I have the answer to my question, but I would like some opinions from the experts on here. I have a small river that feeds into the brackish Arthur Kill between NJ and NY. it is a fairly urban area and i do not trust that the river does not have contaminates in it. What are your opinions on catching the small fish in there with a trap, freezing them, and then feeding them to piranhas. Would freezing them remove all parasite concerns? Should i be worried about contaminates? I believe the area around the river used to be very industrial prior to cleanup.