Scientists study under-appreciated fish with special tag

Most people think of salmon jumping upriver to spawn when they consider wild fish in the American Northwest. But another, lesser-known species—the Pacific Lamprey—is also culturally and historically important to the region. Lamprey have been on Earth at least 400 million years, which is significantly longer than salmon and even dinosaurs.

Researchers at the Department of Energy's Pacific Northwest National Laboratory are striving to learn more about the snake-like lamprey and its East Coast cousin, the American eel.

This spring, researchers tagged fish collected at a local dam with PNNL's super-small acoustic tag designed just for juvenile lamprey. Tagged fish have been released and researchers will track their movements so we can better understand how man-made structures such as dams affect them. This marks the first time PNNL's lamprey tag has been tested in the field.

PNNL's special lamprey tag weighs just 0.08 grams—less than a paperclip—and is designed to be injected with a syringe under a young fish's skin. It's the smallest fish tag that's part of PNNL's larger Juvenile Salmon Acoustic Telemetry System, which PNNL has been developing since 2001 to improve fish-tracking technologies.