You are not off base.2 different studies one yes one no. It is only a question of pond size and plankton density vs. density (# and lbs.) of paddlefish. That is why I said it all depends. Could also state it as how bad do you want PF vs. the risk of harm to your other pond fish . One PF in a large pond with good plankton density may not make much impact but a bunch in a smaller pond could be trouble. ;\)