s-n-f, feeding is good & helpful for bluegill to stay healthy and vibrantly reproduce. I believe that some LMB will also take feed, but this needs verified. It may be that LMB will only take feed if they were raised on feed.

Again, both you and I are probably going at this with limited information, so it may not be a bad idea to make some efforts to get a better idea of the overall fish population.

1) An electroshock survey is maybe one of the best methods (done by a reputable pond consultant). I don't know where to point you for that in CA.

2) Net surveys (cast nets or seines) are very helpful. Through this, you may only see the forage fish, and not the predators.

3) When you throw feed out, many times you can see what different type of fish come to the feed.

Regarding culling, it probably needs to be done with some effort and record keeping. Culling should also be done with your pond goals in mind. If you want huge bass, then you would want to cull more fish so the existing bass would have more food, as an example.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."