Jaws in Illinois

S2, E18: Are dangerous ocean predators prowling American rivers? Few people realize that the bull shark can tolerate fresh water, swimming hundreds of miles upstream from the ocean. History suggests it has at times penetrated up the Mississippi River as far as Illinois. The episode will examine the behavior of the bull shark and dive in the St. Lawrence Seaway to uncover another giant, the Greenland Shark. It can grow bigger than the Great White and has been known to head inland and eat land animals like caribou.