Wildlife Watching Wednesday: The Invasive Sea Lamprey
By: Tom Berg
Sea lampreys (Petromyzon marinus) are native to the Atlantic Ocean. Since Lake Ontario is connected to the Atlantic via the St. Lawrence Seaway, lampreys have been in that body of water for a long time, too. The other Great Lakes (Erie, Huron, Michigan and Superior) were inaccessible to migrating lampreys because of the height and power of Niagara Falls. The lampreys simply could not get up and over this powerful natural barrier.
Unfortunately, when the Welland Canal was completed in 1829 the sea lampreys suddenly had an open path to the rest of the Great Lakes. They easily bypassed Niagara Falls by going through the locks of the Welland Canal and they were confirmed in Lake Erie in 1921. By 1938 they were found in each of the other Great Lakes.
Sea lampreys are an anadromous species, which means they spend most of their life at sea and return to freshwater rivers to spawn. Like salmon, however, they have adapted to living in freshwater all the time and the Great Lakes have taken the place of the ocean for them.
Sea lampreys look like an eel, but they are actually just a primitive fish. They can grow to be almost three feet long, although they are usually much smaller than that. They are often brown, black or even silvery in color. They have no scales and they are extremely slippery. They do not have a normal jaw, either. Instead, they have a mouth like a suction cup which is filled with circular rows of teeth. They use this sucker-like mouth to attach themselves to other fish so they can suck their blood and other bodily fluids. Many of their host fish eventually die. Because of this, these parasitic fish are sometimes called vampire fish.
Don’t worry, though, lampreys are harmless to people and they will not attack you. Since they are an invasive species, they are bad for the Great Lakes. If you encounter one on a salmon or trout that you catch while fishing, please destroy it. The other fish in the lake will thank you.
Have you had a great out experience? Join Global Outdoors and write a review to tell everyone about it! We’re building the home for trusted reviews of outdoor experiences, outfitters, and guides.
