Sea lampreys leave a swath of destruction as the invasive species chomps through the Great Lakes. Attempts to manage them have relied in part on pheromones that attract the animals. After being trapped, they’re either killed or sterilized and released. But these approaches aren’t always effective.

Now there may be a new way to get rid of the lampreys—with the stench of death.

Scientists had seen that dead sea lampreys in a tank caused live ones to freak out and try to escape. So researchers extracted chemical compounds from 10 putrefying lamprey carcasses. They exposed live ones to either the smell of their dead brethren or an ethanol control. They didn’t react to the ethanol, but when they smelled death, they quickly swam the other way.

This effect lasted throughout the entire time the scent was present, and even when the smell was highly diluted. The research was published in the Canadian Journal of Fisheries and Aquatic Sciences. [C. Michael Wagner, Eric Stroud and Trevor Meckley, "A deathly odor suggests a new sustainable tool for controlling a costly invasive species"]

The scientists say their finding could be used to drive lampreys into an area where they could be captured and killed. All while trying to escape from their own imminent smell of death.

—Cynthia Graber

[The above text is a transcript of this podcast.]