Fishing pressure on a public small lake can drastically alter fish behavior and size structure. There have been studies done on small lakes that were closed to fishing, and then subsequently opened to fishing. Size structure often takes an immediate hit, and in highly pressured lakes even bass that get caught and released start getting very picky and harder to catch
There's a reason that the fishing is amazing way up north in Minnesota, the UP, Canada, even though most of those bodies of water are way less productive and have lower biomass. They have way lower fishing pressure