By Marshall Swearingen, MSU News Service

When the headgates opened on the Bureau of Reclamation’s Huntley Irrigation Project on the Yellowstone River in 1907, the engineering marvel transformed the valley east of Billings from sagebrush rangeland into fields green with alfalfa and other crops. Today, the massive waterworks is at the center of another engineering challenge: helping fish access habitat.

Where the river flows over the project’s concrete diversion dam, it becomes a roaring wave that presents a major obstacle to fish trying to move past it. At a creek-like channel built to allow fish to bypass the structure, a pair of Montana State University graduate students have spent their summer gathering data that could one day help improve it.

The students are Haley Tupen, who is earning her master’s in civil engineering in the Norm Asbjornson College of Engineering, and Ian Anderson, a master’s student in ecology in the College of Letters and Science.

Montana Fish, Wildlife and Parks invited MSU to conduct the research after lengthening the bypass in 2015 with the idea that it would be easier for fish to navigate, according to FWP fisheries manager Mike Ruggles. This stretch of river hosts a sport fishery complete with sauger, a native relative of walleye, and burbot, an eel-like freshwater cod. Both species have experienced declines, causing concern among wildlife officials.

“We wanted to make sure this bypass is working, and if not, how it could be improved,” Ruggles said. “The hope is we could apply the findings to other areas as well.”

Anderson and Tupen are carrying on an MSU tradition of engineers and ecologists working together to better understand how structures can be designed to help fish overcome obstacles. Most recently, the MSU Fish Passage and Ecohydraulics Research Group studied ways to optimize fish ladders in the Big Hole River watershed that help Arctic grayling swim over irrigation structures and reach cooler waters during the heat of summer.

“More and more we’re finding that fish move around (in watersheds), and they move more than we expected,” said Alexander Zale, professor in the Department of Ecology and leader of the U.S. Geological Survey’s Montana Cooperative Fishery Research Unit. It’s thought that sauger and burbot are moving extensively up and down the Yellowstone River to spawn, feed and access the best winter and summer habitats, he said.

Starting in March, Anderson, working with technician Evan Matos, a junior at Rocky Mountain College in Billings, as well as FWP staff, captured more than 1,600 sauger, burbot and other fish and fitted each with a small radio transponder. The fish were then released downstream, and radio antennas at the bypass record when the fish pass through different parts of the channel.

“Every day there are multiple detections,” he said. “It’s a ton of data, which is good. It shows that fish are using it to some degree.”

But questions remain about whether certain kinds of fish are more inclined to use the bypass than others, and during what times of the year, he said.