Record setting 240-pound fish caught in Michigan river Robert Besser A 100-year-old sturgeon, a fish weighing 240-pounds, was caught last week in a Michigan river Caught in the Detroit River, the fish is one of the largest lake sturgeons ever caught in the United States, according to the Alpena Fish and Wildlife Conservation Office The sturgeon was released back into the river after being measured DETROIT, Michigan - A 100-year-old sturgeon, a fish weighing 240-pounds, was caught last week in a Michigan river. Caught in the Detroit River, the fish is one of the largest lake sturgeons ever caught in the United States, according to the Alpena Fish and Wildlife Conservation Office.