We spend a lot of money to control sea lampreys. The U.S. and Canada spend $21 million dollars a year to keep them in check.
The invasive fish drills holes into big fish like trout and salmon, and drinks their blood and body fluids. A single lamprey can kill 40 pounds of fish.
Managers are always looking for new ways to control the blood suckers and keep tabs on where they are in the Great Lakes system.
Now, scientists are testing the idea of using environmental DNA – or eDNA. It’s a tool that’s been used a lot to see if Asian carp are in a river or lake; it detects genetic material from the fish.
Margaret Docker is an associate professor in biological sciences at the University of Manitoba. She says that while eDNA will never completely replace traditional survey methods, it could help researchers find larval lampreys in streams.
“It’s sort of a first pass method of trying to find out in what water bodies they might occur and maybe how far upstream they occur,” she says.
Another advantage to eDNA is that it can differentiate native lampreys from the invasive sea lampreys.
“Larval lampreys, they all look fairly similar, although people with expertise can tell the sea lampreys from the good ones, but not necessarily easily," she says. "Morphologically, they look pretty similar but the sea lamprey has a very distinct genetic signature from the native lampreys.”
Docker says it's possible teams could start using eDNA in the field as soon as next year.
The study is published in the Journal of Great Lakes Research.