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Study Measuring Swimming Performance Differences of Wild vs. Hatchery Fish by Staff Columbia Basin Bulletin, February 4, 2011

Fish and laser beams sound like things out of a sci-fi movie, but a combination of the two is being used for important research into the future of rainbow trout.

In a Washington State University lab no bigger than a closet, small rainbow trout race each day to provide information about their wild and hatchery-raised forms. Associate professor Patrick Carter is working with third-year doctoral student Kristy Bellinger to compare the swimming speeds of the two groups.

"We are looking at genetic differences between domesticated and wild trout and determining how those genetic differences potentially can impact the health and wellbeing of the wild trout," said Carter.

While hatcheries may select fish for their size and other factors appealing to sportsmen, Carter said they could be hurting trout populations by weeding out those more fit for survival.

"The data that we have suggests that hatchery fish are slower and less aware of predators than a wild fish would be," Carter said.

"The fish needs burst swimming performance to get upstream in order to cross those small barriers such as rocks or small waterfalls -- also in order to eat and be able to survive predator interactions," Bellinger said.

The fish are kept in climate-controlled tanks, and Bellinger subjects them to multiple trials each time they are used in the fish run.

"I use a net from their individual tanks, and I put them into the swim tunnel, and then I remove a barrier and startle the fish and that's when they race up the track," she said.

A series of lasers times the fish as they go down the clear raceway and sends data to a computer. Carter said researchers previously had to record fish on video, and then slow down the tape and record distance and speed manually.

With all the hatchery programs that distribute fish, rainbow trout are an important factor in the state's economy and way of life, Carter said.

A video on the research is available at www.youtube.com/watch?v=bWSivb-H0k0