the film

NW Scientists Work to Track
Tiny Salmon down Columbia River to Ocean

by Sadie Babits
KUOW, May 26, 2009

3-D is making a comeback in the movies. Now Northwest scientists hope new technologies can help them use 3-D to track salmon. Just as scientists use radio collars to track wolves, now they are using Cherrio-sized sonic tags to monitor tiny juvenile salmon. The tags help researchers develop 3-D animations to plot the fish's movements. Richland Correspondent Anna King traveled to the John Day Dam on the Columbia River for the story.

Getting around a dam is especially hard for juvenile salmon on their way to the Pacific Ocean. All that water moving and noise makes them confused. While they swim back and forth, they become easy targets for predators like birds and larger fish.

They're trying to solve that problem here at the fish tagging lab at John Day Dam. A dozen people scurry around with shallow Tupperware containers holding year-old salmon. The fish don't flop out, they've been drugged. James Hughes is with the Pacific Northwest National Lab.

Hughes: "Once the fish loses equilibrium and is basically at the stage that this one is in, we take him from here to our data station and take all the metrics on him."

After some measurements the tiny fish is quickly shuttled in the Tupperware to the operating table. Matt Wilberding, is one of the scientists doing the intricate surgeries. He says it's important to not drink too much coffee so your hands remain steady.

Wilberding: "I just try to take my time and do a careful surgery and put them back into the holding tank where they will stay for 24 hours and hopefully return to normal state."

A tiny incision, two stitches and the whole surgery takes about a minute. Now, inside the belly of this little salmon are two tags. One of them is sonic tag and about the size of a Cheerio. It tracks salmon's movements in 3-D as they make their way past Columbia River dams like the hulking John Day.

On the top of the dam, senior scientist Jeff McMichael tells me that developing the new tag was pretty tough. The tag in the salmon's belly works by putting out a sonic ping. Your cell phone does the same thing. But McMichael explains this tiny ping has to be detected over the roar of the dams. There are turbines, thousands of popping bubbles, cascading water out of the spillway, electrical generators.

McMichael: "That's a lot of noise."

But the scientists found a frequency that can blast through that underwater din.

McMichael: "We chose a place in the noise environment where there wasn't very much noise."

Now, a fish with a ping in its belly can be heard as far as three football fields away by an underwater receiver. Researchers have placed hundreds of those receivers up and down the Columbia.

The receiver tracks the fish and computers translate that data into an animation. That cartoon shows the movements of hundreds of fish. Some go through the turbines, others go over the spillway, still others make their way through the water slide built to help young fish around the dam.

Eventually this data could be used to modify the dam or change the facility's operations. McMichael says most salmon make it around John Day just fine. But he wants to know why some don't.

Jeff McMichael: "You know all the easy questions have been answered. And it's the hard ones that remain. When you are able to produce information that is necessary to make decisions its rewarding."

On a boat two miles upriver from the John Day Dam the baby salmon are let go, five at a time. A scientist lowers a five-gallon bucket into the Columbia and the salmon silently slip out and glide down into the greenish depths.

They still have the John Day Dam to contend with and 216 more miles of river to the Pacific Ocean. Along the way scientists will be watching their every move.

I'm Anna King in Arlington, Oregon.

Sadie Babits
NW Scientists Work to Track Tiny Salmon down Columbia River to Ocean <- Listen at original site.
KUOW, May 26, 2009

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