haha why use them when you have freshwater drum or shellcrackersLots of coastal saltwater fish either can live in or actually swim upstream when they are young, I've kept a large number of fish in freshwater I've caught in marine environments here in NC. Some die as they approach adulthood like hog chokers, some like mullets can live in freshwater indefinitely but can't breed. If this guy has a breeding population of sheepshead in freshwater the great lakes want his fish to eat the invasive mussels.