While I think it is common knowledge, BG spawn pretty well with no help. I have a clay bottom pond, and the BG seem to reproduce just fine. Has anyone had trouble with BG not spawning in their pond?
A couple of clients do. The pond builder made the sides 2:1 and the slope is too steep for them to pull off enough of a spawn to keep the LMB population fed without serious amounts of LMB culling.
I had that problem last year. I have ample spawning habitat, but once the water depth hit 5 feet, I made the slopes in the pond 3:1 to get as much depth as possible. With the pond being 7' low, there was no spawning habitat covered with water last year and it's not looking good for this year either.