Landlocked Atlantic Salmon Restoration in Lake Ontario and Lake Champlain

Lake Ontario and Lake Champlain once supported some of the largest populations of landlocked Atlantic salmon (LAS) in the world.  Dams, habitat destruction, overfishing, and pollution caused the extirpation of LAS in both lakes approximately 150 years ago.  Past LAS restoration attempts failed due in large part to changes in forage base, sea lamprey predation, poor access to spawning areas, thiamine deficiency caused by eating non-native alewife, and interactions with non-native salmon.  The recent combination of effective sea lamprey control, improved fish passage, enhanced stream habitat, and reduction in alewife numbers in Lake Ontario provide new LAS restoration opportunities.  Current restoration efforts have resulted in hatchery-origin LAS spawning in multiple rivers in both lakes with successful natural recruitment documented annually since 2009 in the Salmon River of Lake Ontario.  Many challenges still remain to restore self-sustaining populations of LAS in both lakes, including the introduction of alewife to Lake Champlain in 2003.  We will discuss ongoing adaptive management experiments in the lab and field focused on optimizing hatchery practices to enhance survival, improve imprinting, and increase adult returns of hatchery fish used for LAS restoration.