I started it a number of years ago on Codorus Ck in what was then the stocked trout section around Menges Mills, below the former DH Area. There may be other AFM's trying it now; I am not certain. In the Codorus case it was done in combination with eliminating one of two inseason stockings and was done to enhance the Class D or C wild brown trout population. The brown trout population increased to a very substantial Class A biomass. Previous work on the section above prior to it being designated as a DH Area and subsequent studies of that section's positive wild BT response to the DH regs despite VERY intensive stocking of the DH area at that time (BT went from Class D to A) encouraged Tom Greene and me to believe that reducing angling pressure by stocking RT would potentially have beneficial effects in the section below the DH area. RT are relatively quickly harvested and, therefore, long-term pressure is reduced. So, the theory behind stocking RT over wild trout populations when stocking is occurring anyway is that the RT will provide a quick fishery (easily harvested in cold water), anglers will perceive the reduced density of stocked trout, and then will move on to other waters. Whether it works on other waters or with wild brook trout remains to be seen. I have tried it on York County's Leibs Ck (wild BT), but have not evaluated the results yet. I have also tried it on Schuylkill Co's Cold Run (wild ST). The ST population appeared at first to improve to Class A, but then returned to its standard Class B biomass. So the jury is still out.
One thing that Codorus did show was that you can stock the heck out of a stream section with adult trout, maintain a high density of stocked trout through conservative regulations, and still see a very minimal wild trout population that is present in the section grow to Class A proportions and beyond if the habitat is suitable. In this specific case a strong argument could be made that harvest associated with trout stocking under general regulations had been limiting the development of the wild brown trout population, but when harvest was nearly eliminated (or greatly reduced) under DH regs, the wild brown trout population increased substantially despite the heavy stocking that many anglers and some biologists tend to believe will by itself substantially depress a wild trout population. It is important to note that prior to becoming a DH area, the section was very heavily pressured; it was not your run-of-the-mill angling pressure seen on most stocked trout streams AND it was during an era when C&R fishing on regular stocked trout waters was nearly unheard of (perhaps 10 percent of the anglers practiced it).
