A lake can only carry so much predator biomass. The muskellunge sits at the top of its food web, requires large prey, defends a home range, and grows slowly toward a body size that few freshwater predators reach, so populations are thin by necessity rather than by depletion. Survey work in North American musky waters commonly reports adult densities below one fish per hectare, and often far below.
That biology shaped how the fishery is managed. Minimum size limits on muskellunge are among the highest applied to any North American freshwater fish, and voluntary catch-and-release is close to universal among specialist anglers, because a lake cannot replace a large adult quickly.
Hybridisation complicates records. Muskellunge and northern pike interbreed to produce the sterile tiger muskellunge, and some historic trophy claims have been questioned on identification grounds, so the size record for the species has been subject to review.