Roy, I would definitely go the kill route. With the pond being upstream, and containing unwanted species, there's about a 100% chance they end up in the big pond, which would basically ruin your plans of SMB, YP and RES. I really like your idea of using this smaller pond as kind of a supplemental stocking source. Adding fish is not always the answer, but when it is you'll have a pretty creative way to do it. Keep us updated! Sounds very cool!