'Like something out of a horror movie': Scientists tackle invasive sea lampreys in the Great Lakes

PIEN HUANG, HOST:

Let's check in now on a decadeslong environmental effort focused on a creature that sounds honestly like a nightmare.

MARC GADEN: A tooth-filled mouth, about 100 teeth - The mouth is a suction cup on the end of a snake.

HUANG: He's talking about sea lampreys.

GADEN: The teeth anchor the lamprey mouth to the side of the fish, and then a sharp tongue like a file flicks out and drills its way through the scales and skin of the fish to feed on the fish's blood and body fluids. It's like something out of a horror movie.

HUANG: Oof. And Marc Gaden says if they're left unchecked, lampreys could have ended what's become a $7 billion fishing industry in the Great Lakes. Gaden is executive secretary of the Great Lakes Fishery Commission. It's a group that's been working since the 1950s to curb the invasive lamprey population that first made its way to the lakes through canals.

GADEN: Each sea lamprey will kill about 40 pounds of fish, and each female lamprey will lay about 100,000 eggs.

HUANG: The commission's lamprey control program went on pause during the COVID pandemic, and the numbers ticked back up.

GADEN: These sea lampreys bounced back so quickly, it actually astounded a lot of the people in the control program.

HUANG: OK, but here's some comforting news for humans - lampreys only target fish.

GADEN: Nobody needs to worry about being attacked by a lamprey. They don't like warm-blooded creatures.

HUANG: And the better news - this summer, Gaden says thanks to interventions like using a pheromone that lampreys love to chat more of them, these slithery invaders are dwindling back towards pre-pandemic levels once again.

GADEN: We're cautiously optimistic that we'll be meeting the control targets very, very soon. So it really is a success story.

HUANG: In other words, so long, suckers.

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