PNNL

When thinking of migrating fish, most people’s minds fill with images of majestic salmon vaulting themselves over waterfalls. Few conjure thoughts of the American eel and Pacific lamprey. Though unglamorous, eels and lampreys still play a pivotal role in the health of oceanic and riverine ecosystems.

Lampreys spend the majority of their lives in fresh water rivers, migrating out to sea as juveniles only to return a year or two later as adults to spawn. Adult eels, on the other hand, migrate to the ocean to spawn with juvenile eels returning inland. For both, hydropower dams impede their route.

To better study the interesting, and extraordinarily long lives of these species, PNNL researchers have developed the sturgeon transmitter. This new model of fish tag uses the Juvenile Salmon Acoustic Telemetry System (JSATS) in a new way. These tags are small, long-life acoustic transmitters that can detect receivers left along rivers and other waterways up to 500 meters away—perfect for fish like sturgeon and adult eels that live deep underwater. Furthermore, these tags have a longer lifetime than most, which is also a good match for these species.

How JSATS Tags Work

Since 2001, with funding from the U.S. Army Corps of Engineers’ Portland District, PNNL researchers have increased the JSATS tag’s sophistication and decreased its size to create an overall more effective fish tracking tag. The JSATS fish tags release quiet beeps that are picked up by receivers placed in rivers, lakes, and other water bodies as tagged fish swim by. Receiver data helps researchers map out the precise 3-D location of each fish and determine if fish are injured during their travels. The information helps make dams more fish-friendly by providing insight utilities can use to revise hydropower operations or alter structures. Over the years, hundreds of thousands of young fish have been studied with JSATS tags.