Winston,
Indeed a complex situation...now we have multiple ponds and situations to address.
Timing is a major factor here I believe.
What I mean is..it could be, could be, that the LMB became stunted/overpopulated from years of neglect (reducing the small BG to almost nothing), then someone came along and with good intentions threw in a bunch of Tilapia trying to "fix" that problem. Result, more stunted LMB and no BG and no winter forage and huge Tilapia. Yes, I'm just kicking around ideas, but isn't this a possibility and does it not explain the situation? at least the situation in one pond.
The question is how to remedy it...If I'm right, you have to get those stunted LMB and those carnivorous
large Tilapia out of there....and re-establish BG.
