Impacts Of Sea Lamprey On Lake Trout

Lake Trout Population >>

Sea lampreys are invading predators in the Great Lakes.  Sea lampreys feed on blood from large fish species.  Since large fish are larger, they have a higher blood content making them a target for sea lamprey.  This will affect the population of fish species in the Great Lakes because there will be less large fish and more small fish.  The number of lake trout found in the Great Lakes declined due to predation by sea lamprey.  Lake trout were at the top of the food chain so; they did not know how to deal with predation by invasive species.  They evolved in a cold environment making them vulnerable to invasive species.  Lake trout were particularly vulnerable to sea lamprey.  When sea lampreys first invaded Lake Huron the population of lake trout dropped from 1.5 million kilograms to virtually zero over a 10 year span, 1937 – 1947.  The lake trout population collapsed in Lake Huron during the 1940s.  The population of lake trout in Lake Superior declined similarly to the population in Lake Huron during the late 1940s.