Eric hit it on the head. Thick weeds can often be a major issue. If a vast area of your pond is covered in certain species of submerged aquatic vegetation that doesn't allow movement of predators access, it provides too much refuge for BG, BC, etc... Some species like hydrilla, elodea and some species of pondweed get very thick. Other species, like American pond weed, eel grass, are not as thick, provide cover for forage fish, but still allow efficient predation on them by the ponds predators.
LMB are much better at foraging on prey in thick environments while HSB are an open water specialist. Structure is something that can be tweaked fairly easily. Particularly if starting from scratch or working with an older pond that never had much structure put in it to geing with. We all know the importance of fish attracting structure. It concentrates fish into smaller areas making it easier for us to catch them. It can also make it tougher for predators to prey on forage, depending on several factors. It could also make it easier for predators to prey on them. As we all have heard, it all depends... If I was doing the HSB BC pond in an effort to grow large BC, I think limiting structure would be a good idea. This would allow the HSB to more efficiently prey upon the BC.
