I am not by any means an expert, but I would not throw out the idea of trout all together. As you said, they were once native. That would mean to me you have the climate, soils, water etc to sustain trout. The size, shape of your pond may have changed, but these essential elements have not. Even as a suplementary species, you may consider stocking a few. Aeration will most likely help you to achieve your goals regardless of species. I am partial to trout, not for their taste, yuk, but pound for pound are hard to beat from an angling point of view. (And that's all my repressive gov't will allow pond owners to stock). I also wonder what happened to your planted trout, are they actually gone, or just hard to catch. See, now I upset both the bass fisherman and now you. Just my 2 cents anyway. Good luck with your pond, you found the right place here anyway. Wood