Evaluating Future Need of the Gull Island Shoal Lake Trout Refuge in Lake Superior

Lake Superior is one of the largest lakes in the world and historically supported one of the largest and most diverse lake trout fisheries in the Laurentian Great Lakes. Lake trout stocks collapsed throughout Lake Superior because of excessive fishery exploitation and sea lamprey predation, so stocking and fishery regulations were enacted to support stock restoration.  A refuge was established around Gull Island Shoal to enable recovery of the lake trout stock that spawned on this historically important spawning shoal in the Apostle Islands region. Lake trout stocks in the Apostle Islands region of Lake Superior are nearing carrying capacity, so may be able to sustain commercial and recreational fisheries.  The purpose of this project was to determine if future lake trout stocks depend on the Gull Island Shoal refuge to remain at sustainable levels. To achieve this we constructed an age-structured simulation model to assess the exclusion and inclusion of the refuge, as a harvest management tool, on sustainability. Results will be used to guide state-tribal fishery management in determining the future status of the Gull Island Shoal refuge. We expect to find that the refuge is crucial for sustaining lake trout stocks in the Apostle Islands region.