RAH,

I don't think there is any downside to having GAMs in your planned combination. If they reduce recruitment of CC and BC, (something they could do by competition with and predation of fry), then this would likely help to moderate overpopulation. GAMs reproduce a lot and their offspring reproduce in the same year if they are born soon enough. They don't have spawning behaviors that work against them. The young are usually born swimming with yolks fully absorbed. That's a big advantage that allows a population decimated overwinter to recover to capacity by midsummer. Speaking only from my limited experience, if LMB are present, they need lots of cover to persist. They maintain populations in ponds near me particularly where there is abundant APW. One pond, which in some respects is very much like the combination you plan, has CC, GSF, and BG. Both GSF and BG are very abundant in this pond and large enough to consume GAMs but the GAMs hold their own going on now for 3 consecutive years. They reach (I think) densities that saturate the ponds ability to carry them. Every square meter has hundreds of GAMs by September within eyeshot of the shore. I see them in water much deeper than inches and I see sprays of small fish that I think are Gams evading predators too far from shore to positively identify as GAMs. I also see lots of schools of small fish that move around the open spaces disturbing the surface feeding. I think they are GAMs ... but can't say for sure.

There is never a great standing weight of GAMs even though they are numerous. But GAMs grow fast reaching reproductive age in about a month. Even adults can eat more than their body weight each day (Adult females put that energy into growth and reproduction). The point I am making is that this ravenous appetite means they are either growing very fast or that they are having a lot of offspring. So even a small standing weight can contribute as much as 10% of its standing weight (every day) to mortality and maintain the population biomass.

As far north as you are ... and in a shallow pond ... you may have significant winter losses but provided you can get 1/2 lb or so to survive each year they will rise like a phoenix to numbers that are no less than remarkable providing many, many times their overwintering standing weight in forage.