In recent years, Lac Seul in northwestern Ontario has been the site of a fast growing trophy fishery for muskellunge (Esox masquinongy). Concern about the sustainability of this fishery prompted a catch-and-release regulation to protect the fishery while studies were initiated to investigate the status of the muskellunge population. Preliminary date indicates angler catch-per-unit-of-effort (CUE) declined by more than 50% in a three year period. Compared to other trophy musky populations, the fish are fast growing with a high theoretical maximum length. There is a possibility that, despite the catch-and-release regulation, the trophy fishery may not be sustainable at recent levels of angling effort.