Scientists Plan to Exterminate Sea Lamprey Larvae in Lake Michigan with Poison

Sea lampreys are a huge issue in the Great Lakes. They latch onto native species of fish with their sharp teeth, growing as they feed on the animal's juices like some kind of giant leech. Eventually, the parasite can kill the fish. But now, officials are taking steps to eradicate this creature from the lakes. They're planning on poisoning the larvae of sea lampreys in a stream feeding Lake Michigan this week.

Sea lampreys probably first entered the Great Lakes in the 1830s via manmade locks and ship canals. More specifically, they arrived first in Lake Ontario. Improvements to the Welland Canal in 1919 eventually allowed the creatures to bypass Niagara Falls and enter Lake Erie before they spread to the upper Great Lakes by 1939. Since then, the lampreys have helped devastate trout populations in the region.

These aquatic animals actually have a complex life cycle. They first go through an extended larval phase before metamorphosing into the bloodsucking parasitic phase that most people are familiar with. They spend a year feeding on fish before detaching from their host and migrating to tributary streams where they build nests in gravel; females then spawn an average of 60 to 70 thousand eggs.

Now, the U.S. Fish and Wildlife Service plans to cull this population of sea lamprey larvae, according to the AP. They're going to administer treatments to the creek that flows through Traverse City State Park before entering Grand Traverse Bay's east arm. Officials are hoping that by poisoning the larvae, there will be fewer lampreys that will suck the blood out of unsuspecting fish.

Keeping these creatures at bay is expensive, though. The fight against sea lamprey has cost more than $400 million over the past five decades. That said, officials are making strides. The lamprey population has dropped by about 90 percent since researchers have perfected a way in the late 1950s to kill lamprey but not other species, according to the AP.

Yet it's not only the Great Lakes that are suffering from this invasive species. The lampreys have also been discovered in New York and New Jersey. In fact, a massive specimen was recently pulled from the Raritan River in northern New Jersey. The creepy photo of the creature made its rounds on the Internet as people speculated exactly what it was.

Hopefully, this latest effort will help stem the tide of these lampreys from entering the Great Lakes. How effective the poison will be, though, remains to be seen.