"The sea lamprey is an eel-like, jawless fish that entered the Great Lakes from the east coast of the United States through the canal system. It feeds like a monster in a low − budget horror movie − it uses its mouth to attach itself to a healthy fish, gore through its scales and skin with its tongue, and suck out its fluids. The sea lamprey has contributed to the extinction of three species of cisco fish and the collapse of commercial fisheries. (Invasive Species Specialist Group)"
That's right, kids. There are no sharks in lakes. But counsellor Claire didn't tell you there are FOOT-LONG BLOOD-SUCKING VAMPIRE EELS.