New data could help scientists around the world study fish passage through dams


Researchers at the Pacific Northwest National Laboratory are tagging young Chinook salmon with tags slightly larger than a grain of rice.

Pacific Northwest National Laboratory

Tiny devices, smaller than a few grains of rice, help provide tons of data to researchers tracking salmon around the Northwest Dams.

Scientists hope this data on juvenile Chinook salmon could help expand understanding of fish behavior and survival in a cost-effective and efficient way at other dams around the world.

“We believe this unique dataset can be very useful to the scientific community for purposes beyond what we have done so far,” said Daniel Deng, a mechanical engineer at Pacific Northwest National Laboratory, who developed the tiny stacks for the tags.

How juvenile fish cross dams.

How juvenile fish cross dams.

NOAA Fisheries

The more than five million raw data points released by the Pacific Northwest National Laboratory give other researchers a head start in studying fish passage through dams, said Jayson Martinez, a mechanical engineer at the lab involved in the the research.

“If someone tried to recreate this dataset on their own to test different hypotheses they might have. That would be very expensive and difficult to do,” Martinez said.

Ultimately, he said, the hope is that other researchers can take the data and move beyond the research in the Northwest.

A telemetry system, known as Acoustic telemetry system for juvenile salmonhelped collect data on tagged salmon.

Researchers implant tiny acoustic tracking devices in the salmon.

The tiny tags help researchers track small fish without stressing them too much, said Alison Colotelo, who leads research on sustainable hydropower operations at Pacific Northwest National Laboratory.

“We can do surgery very quickly, sometimes even without using sutures or anything to close,” Colotelo said of the tag implantation.

In water, the acoustic beacon sends out a ping signal every 3 to 5 seconds, she said.

“Each fish tag has a unique code, so it’s almost like your social security number,” Colotelo said. “We can see each fish individually as they go down the river.”

The system helps monitor the behavior of fish as they approach the dams and continue to head downstream, she said.

McNary Dam

McNary Dam

Pacific Northwest National Laboratory

In the northwest, young fish have four main tracks to bypass dams: by a weir, on a surface outfall road, by the turbines or by a juvenile fish passage system that funnels fish around the dams.

As the fish approach the dams, the scientists collect information on where the fish are swimming, how long it takes them to pass the dam, the route they are taking and if they survive, Colotelo said.

Studies have found that 60 to 70 percent of young salmon pass over dams through surface spills, Colotelo said.

“The fish usually survive very well through this route so they can somehow get through the dam and continue their migration,” she said.

Next, Colotelo said, the researchers plan to study the health of the tagged fish, as well as their location.


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