May 13, 2019

PNNL’s Miniature Tags Track Eel and Lamprey Migration

Fish researchers publish video journal, document high survivability; less than 3 percent of fish lose tags

Pacific Northwest National Laboratory has developed a super-small acoustic tracking tag designed specifically for juvenile lamprey and eel. In this video, PNNL researcher Alison Colotelo describes how she and her colleague Kate Deters inject young lamprey with the PNNL tag.

Eric Francavilla | Pacific Northwest National Laboratory

A trio of PNNL fish researchers recently published a video journal article on how to properly implant miniature acoustic tags in juvenile Pacific Lamprey and American Eel and how the tags could benefit migration.

The video journal details laboratory trials using the tags from PNNL's accredited Bio-Acoustics & Flow LaboratoryThe tags, part of PNNL JSATS’s tracking suite, track the lamprey and eel and provide information about their behavior near hydropower dams.

The trials conducted on juvenile lamprey and eel indicate that the tags can be successfully implanted on both species without affecting their swimming ability or survival. There also is minimal tag loss over the tag life of 30 days.

A decline in fish numbers

As the population of the Columbia River Basin’s lamprey has declined over the past 40 years, experts have been researching ways to preserve the species near hydroelectric facilities, specifically dams. Juvenile lamprey migrate deeper in the water column than juvenile salmon and are less likely to pass through the juvenile bypass systems. This makes it more difficult to detect the species and gather information with other types of tracking transponders. However, learning about lamprey behavior and survival is important for developing mitigation strategies for downstream passage, including bypass system design for use at dams.

Eels raised at the Aquatic Research Laboratory
Eels swim inside tanks at PNNL's Aquatic Research Laboratory. PNNL researchers are studying eel and lamprey behavior near dams by implanting both species with miniature acoustic tags.

Like the lamprey, the American eel population has dramatically declined over the past several decades. The once-abundant species has dropped by 50 percent in Chesapeake Bay and by as much as 97 percent in Lake Ontario, according to reports by others that the researchers cited. The species is currently listed as endangered under the Ontario (Canada) Endangered Species Act. The development of hydropower facilities also has created obstacles for eels, which swim downstream.

A tag solution

Before PNNL’s development of the micro acoustic tags, tags were too large to be successfully implanted in the body cavities of juvenile lamprey and eel. PNNL’s micro acoustic tag is small and easy to implant. It measures 12 millimeters in length by 2 millimeters in diameter and weighs 0.08 grams in air. The implantation of the tags doesn’t require sutures and involves a small incision of less than 3 millimeters in length. The lamprey/eel tags emit unique coded signals, which are monitored through autonomous receivers, or hydrophones, at fixed structures or in-river receivers..

The team determined the tag did not affect or change the lamprey or eel’s swimming ability. Less than 3 percent of the lamprey lost tags and 3.8 percent of the eel lost their tags, researchers reported. None of the lamprey or eel died during the 38-day holding period.

PNNL’s technology provides scientific information that can be used to develop strategies or designs for downstream passage.

For more information on obtaining a license for the eel and lamprey tag, contact Sara Hunt, PNNL technology commercialization manager.

This study was funded by the U.S. Army Corps of Engineers and the DOE's Water Power Technologies Office.


About PNNL

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit For more information on PNNL, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Published: May 13, 2019

PNNL Research Team

Daniel Deng
Robert Mueller
Stephanie Liss