06/22/2026
It's Pacific Lamprey Week, and we’re celebrating with one of our favorite facts about these ancient fish: They are not sea lamprey.
Pacific lamprey sometimes get a bad rap—often in the comments of our social media posts or when visitors from the Midwest see them in our fish viewing windows—but these lamprey are not the same as the ones known for invading the Great Lakes.
There are roughly 40 species of lamprey.
Sea lamprey entered the Great Lakes through locks and manmade shipping canals in the mid-1800s and are now considered a “pest” across the region.
Pacific lamprey, on the other hand, are perfect angels. These lamprey are native to the Pacific Northwest and, while parasitic, have coexisted peacefully with their host species for millennia.
Here in our region, Pacific lamprey actually help salmon and other species by adding more marine nutrients back to aquatic ecosystems. Those nutrients contribute to the health of our rivers and streams.
They’re also very culturally significant for the tribes of the Columbia Basin. They're an important first food and have also been used for medicinal purposes.
And they've been around longer than trees and dinosaurs, which is a neat fact you can share with your friends. (Talk about an ice breaker!)
For many reasons, these are a species we value greatly and want to protect, which is why we have entire teams dedicated to improving lamprey fish passage on the Columbia River.
STOP CONFUSING THEM WITH SEA LAMPREY!!!
(respectfully)
Pro-Tip: You can tell the difference between Pacific lamprey and sea lamprey by looking at their teeth. Pacific lamprey have the signature three teeth. It’s even in their name (Entosphenus tridentatus).
