ill try to answer all your questions at once but i have a few uncertanties. it is a man made pond that came from a swamp so half of it is full of stumps and is 4 feet deep throughout all the swampy area and is pretty choked with curly leaf pondweed and coontail but in the dug section of the pond there are very few clumps of coontail and is primarily clay rock and course sand. the water is crystal clear so i can see the vast amount of little gills and as for bass population all the bass are well fed and i think are thriving on crayfish and frogs and younger bass. the little gills hide in the thick weeds out of range for any bass to get them. it is all catch and release and in my 8 years of living on this pond only one bass has died from swallowing a crankbait. when we went to see what was in its stomach all we found were a frog some crayfish shells and a little bass. we only fish for bass and can careless about the bluegills. with a strictly bass pond with possibilities of another gamefish being stocked in mind what is the best way to preserve the bass population but reduce the amount of all the gills.i would prefer to stock another gamefish in there for something else to catch than bass but will help reduce the bluegills