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Lamprey get the green light on trip past Rocky Reach

by Kimberlee Craig | Jul 12, 2018

How about this for a tough commute? Imagine traveling nearly 500 miles to get home up the Columbia River from the ocean to Entiat with no bones, no paired fins and not being a great swimmer like salmon.

 

That’s the challenge Pacific lamprey face as they navigate the Columbia looking for streams to spawn.

 

Study, tracking and working with tribes and fish agencies led Chelan PUD to make changes to the fish ladder at Rocky Reach Dam to improve the trip for lamprey.

 

The new features offer what amount to a green light for these ancient, eel-like fish as they move past the dam.

 

Stop-and-go is just the ticket

It turns out lamprey like a stop-and-go approach to moving up the river. They use their round mouth and raspy teeth to attach to river-bottom rocks and gather energy for tail-powered “bursts” forward.

 

The PUD installed ramps to connect concrete steps in the fish ladder that provide convenient spots for lamprey to attach. And, grates installed over small gaps in water supply pipes keep lamprey from slipping in and getting lost.

 

The result is 98 percent of adult lamprey that enter the fish ladder at Rocky Reach are traveling on up the Columbia to spawning streams.


See how fish are traveling past our dams today

Ancient travelers 

Lamprey are highly valued in Native American culture and tradition. They also hold an important role in the food chain and stream ecology. Lamprey are native to the Columbia River, dating from 450 million years ago.

 

They hatch in freshwater streams, spending up to seven years before migrating to the ocean. There they attach to larger fish and grow as a parasite off the host. Then Adult lamprey return to the Columbia, traveling upstream to spawn.

July and August are the perfect time to visit Rocky Reach Discovery Center to check out the lamprey and other fish headed upstream to their home waters.

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