Thanks all for the interesting and varied advise. As stated in the title of this thread, I am planning on adding some sunfish as well as trying to re-introduce some golden shiners. I just thought I would bring people up to speed as to what has happened since I started this experiment about 7 years ago.
I know the SMB may not be enough to alone stop the sunfish from stunting. However with the very large YP as well as the herons I think that I may be able to keep things under control.
