A lot of factors play into this which is why it is hard to help any type of fisheries in many states. Here are the ones off the top of my head caused by anglers: Pressure, poaching, fishing for the 1 man or party limit every trip, new boom of anglers, not knowing or keeping up with regulations, technology, and probably more. Working at a bait shop up here in WI I can gladly say majority of people here fish to eat regardless of age, although more popular in the old timers than young. Its hard to find trophy fish of any kind up here unless your out every day, so the majority of those guys that do find that trophy fish just ends of mounting it. I can safely say if a bass is 5lbs and up its getting mounted. Poaching is another big thing up here too which the DNR can't do anything about unfortunately.