If you see people who look like the Ghostbusters wading around through Western New York waterways, they are on the hunt — but not for paranormal activity. They are looking for an invasive species.

Nathan Hudak and Hannah Goodman are biological technicians with the U.S. Fish and Wildlife Services surveying for invasive sea lamprey larvae. Sea lampreys made their way into the Great Lakes through man-made canals and locks. They use their teeth to attach to fish, not humans, and slowly kill them.

They are a threat to not only the ecosystem, but also the $7 billion fishing industry.

“We have gotten it down from its historic high, which was about 2.5 million sea lamprey in the Great Lakes. And it's about 90% down from that historic high,” said Hudak.

They wear protective boots, waders and rubber gloves to stay safe from the elements, but also the electrical shock their backpacks send into the water. It helps bring the larvae up from the silt in which they are buried.

Fishermen who catch fish with the invasive sea lamprey attached are advised to humanely kill the lamprey.