Bob-O: generally speaking, we figure that northern pike are getting to high density at about 10 pounds/acre. They rarely get to more than about 20 pounds/acre, probably because they are eating machines, as you already know. We used rotenone to kill a 3-acre gravel pit that had green sunfish and northern pike (wild caught fish that someone caught and moved to "help" the pondowner). The pond had four northern pike total, at about 6.5 pound average size. That's 26 pounds in a 3-acre gravel pit. That's probably a little lower than what a "hill pond" might support, as our sand and gravel pits are not too fertile here. The green sunfish were low in number and small in size.
The northerns were healthy and sure would have been fun to catch. Obviously, it would have primarily been catch and release fishing.
