I have noticed first hand of what you are worried about. The pond I manage for my friend had amazing fishing for the first 3 years until he started letting people fish it too often. I knew the fish where still there I would see huge bass, crappie, and bluegill, but they became much harder for people to catch. I told him to not let so many people fish there as I knew this was hurting the 2 acre pond. We'll have to see how the fishing is in the spring to see if it helped any.
