If fish could talk
On April 14, 2010, Wyoming Game and Fish Department Sheridan Region Aquatic Habitat Biologist Travis Cundy opened two control structures on a newly completed bypass and water began to flow into a constructed rock-filled channel. Within a few hours, any fish moving through that area was able to continue its journey another 36 miles upstream for the first time in a century. Using a natural bend in the creek, the bypass that is still in use today runs 800 feet and connects Clear Creek above and below Kendrick Dam.

The 112-mile Clear Creek is a tributary of the iconic Powder River, one of the longest unrestricted prairie rivers left in North America. It travels 430 miles northeast from its headwaters west of Kaycee before meeting up with the Yellowstone River in eastern Montana. Kendrick Dam, completed in 1911, created a barrier that stopped fish from the Powder River from traveling more than seven miles up Clear Creek. What native and game fish species have done since that April day more than a decade ago is the focus of a recently initiated study on fish movements in northeast Wyoming incorporating traditional sampling methods and advanced technology.

Researchers are comparing the kinds of fish and their distribution in the 36 miles of Clear Creek above the dam with information prior to the bypass installation.

“It will also help us know how much the furthest upstream barrier that still exists is hindering fish movement upstream,” said Gordon Edwards, a Game and Fish fisheries biologist in the Sheridan Region co-leading the study. “We will look at whether it would be worth it in the future to pursue building another bypass structure and how beneficial it would be to push further upstream.”

The study also will provide fisheries managers new insight into the goings-on of large-bodied fish in the Powder River. The Powder River hosts the highest overall diversity of native fish in Wyoming with 20 species. However, information on many of these species has been hard to come by due to the Powder’s erratic flows and unpredictable nature. In the spring, it runs high and fast, precisely the conditions some fish species prefer when making long-distance movements, but it stymies work of fisheries biologists.

“We can’t safely or effectively sample the Powder River during spring when fish are moving due to high flows, sometimes as high as 10,000 cubic feet per second,” said Paul Mavrakis, Sheridan Region fisheries supervisor. “It makes net sampling very difficult and electrofishing impossible. When the Powder is really flowing, we can’t even touch it; it is too big and too wild. The way we’ll be able to sample fish now during those migratory time frames is by ‘listening’ to them.”
Top three

For years, fisheries biologists have used various sampling methods to document movements of fish in the Powder River drainage, but each one had drawbacks.

“We tried pit tagging, floy tags, trapping fish and electrofishing. It all partially worked, but radio tags are a new technology we haven’t tried,” Edwards said.

In summer 2021, Edwards, statewide fisheries biologist Stephen Siddons and several technicians began laying the study’s groundwork by sampling stretches of Clear Creek and the Powder River. They captured, weighed, measured and recorded species of fish they caught. For three species: goldeye, sauger and shovelnose sturgeon, an additional step was added — implanting radio tags.

“Shovelnose sturgeon, sauger and goldeye are all highly migratory species,” Edwards said. “Each has its own life history that seeks certain habitats during different life stages as well as seasonally. Each is also listed as a Species of Greatest Conservation Need in Wyoming and a lot is still unknown about how and when these fish move around.”

To better track these species, a radio tag is surgically implanted in the fish’s stomach cavity, and the opening is sutured shut. Each tag is activated before it is implanted, and it emits a radio signal every five seconds. Fisheries biologists selected radio tags for each species to ensure tags weren’t too large.

“We always take great efforts to not influence fish behavior when tagging fish for movement studies because it would provide biased data and not reflect what the population as a whole may be doing,” said Siddons, another co-leader of the study. “By selecting the smallest tag possible for each species, we believe this isn’t an issue.”

Prior to capture efforts, and with the support of local landowners, four stationary telemetry receivers were constructed — two on the Powder River and two on Clear Creek — to track the fish. The stations feature two antennas, one facing upstream and one facing downstream. A fish’s direction of travel can be determined based on which antenna picks up the signal first. A data recorder and solar panel for charging the battery system completes the unit.

“The receiver hears the tag and deciphers the tag’s unique code so we know which specific fish we are encountering,” Siddons said. “The radio tags are generally detectable one-quarter to a half mile away.”
In addition to the stationary receivers that wait for signals from a passing tagged fish, Edwards, Siddons and others actively tracked fish on foot with handheld telemetry equipment and two aerial surveys were conducted in August and November.
Tags in the water

During the 2021 field season, 63 fish were radio-tagged.
Twenty-three sauger were captured and radio-tagged, with 17 detected in later months. Most of them stayed close to where they were tagged, but one motivated individual traveled 47 miles upstream in just over two weeks.

Although they are abundant, little is known about goldeye movements. No previous radio-tagging studies have been done on them and a search of scientific literature provided scant information. The 35 implanted with radio tags between April and June 2021 will provide a foundation of information on this species.
Thomas Luttrell, Wyoming Game and Fish Department fisheries technician, holds a sauger collected from below Kendrick Dam. A telemetry project is helping researchers evaluate how fish use a channel built in 2010 to bypass the dam and continue upstream. (WGFD photo)

“This is the first radio telemetry project we know of to document movements of goldeye, so we had to learn how to safely implant those tags,” Siddons said.

The movements of shovelnose sturgeon are of specific interest to Edwards and Siddons. Prior to the completion of the Kendrick bypass, now-retired fisheries biologist Bill Bradshaw, who initiated the project, predicted 20 species would use the structure and move upstream in Clear Creek. Of the 20, only the shovelnose remains to be documented above the dam.

Five sturgeon were captured in 2021, and one had a particularly exciting background. On June 7, researchers captured a sturgeon that was already marked with a floy tag from Montana Department of Fish, Wildlife and Parks. Floy tags do not emit signals, but are small, thin tags biologists insert into the muscle tissue under the skin, usually near the dorsal fin. The tags are stamped with a unique number and contact information anglers or others can use to report when and where they later capture the fish. After visiting with MFWP fisheries biologists, it was learned the sturgeon was first captured on Aug. 24, 2020, 290 miles downstream near Terry, Montana where the Powder joins the Yellowstone River.

“Several of our tagged goldeye and shovelnose sturgeon also moved all the way down to the Yellowstone River in 2021, which was a bit of a surprise,” Siddons said. “The first year of these projects in a new system is always a fun learning curve.”
Sharing information

The timing of the Clear Creek-Powder River study coincides with a new project taking place in Montana that has implications for Wyoming. In April, the U.S. Bureau of Reclamation completed a bypass structure on the Yellowstone River near Glendive, Montana. The Intake Diversion Dam, completed two years prior to the construction of Kendrick Dam, previously prevented upstream movement of most fish since the dam was constructed.

“In speaking with Montana fisheries biologists, they expect many species to migrate upstream at a magnitude unseen for 100 years,” Edwards said. “These will include many individual fish implanted with telemetry gear by Montana Fish, Wildlife and Parks biologists and our ground-based receiver tracking stations should be able to detect movements of these fish entering Wyoming at the border and near the Crazy Woman Creek confluence.”

The Game and Fish-tagged fish are detectable by existing MFWP telemetry receivers and the two states will be able to share movement data for several years. While the smaller Goldeye tags’ battery life is only about 300 days, the sauger tags should last about 560 days and the sturgeon tags about 880 days.

“These species likely migrate or move over such a large area that if we only listened for them in Wyoming, we definitely would not be seeing the whole picture,” Mavrakis said. “Seasonality of fish use in the Powder and lower Clear Creek will be really interesting to tease out. We think some of these species only come to Wyoming during spring runoff but this study will help us determine if that is true and determine where the fish spend the winter.”

What’s next?

This year’s field season will focus on capturing and implanting the remaining 45 tags in individual fish during the spring and summer.

“We revised our targeted numbers for tagging each species after closely evaluating our chances of capturing shovelnose sturgeon and taking stock of our project budget,” Edwards said. “The big tags used for sturgeon are much more expensive than the others and we wanted to get the most bang for our buck. Based on our experiences last year, we shifted some money in our budget to buy more goldeye and sauger tags to implant in 2022. We basically want as many tagged fish out there as we can afford, so we put some strategy into our purchases.” 

The team also plans to increase aerial surveys to collect more movement data and will increase sampling in Clear Creek of small-bodied fish such as plains minnow, sand shiner, sturgeon and flathead chub that cannot be tagged, to begin building a picture of their movements and the possible impacts upstream barriers might be having on their ability to colonize the higher reaches of the creek.
Final data collection and analysis will take place over the winter of 2022 and 2023 with a project completion report readied for spring 2023. However, Edwards said early results have already made the study worthwhile.

“A lot of our knowledge has been based on assumptions about these fish,” he said. “Now we will have improved data to help us understand what really goes on with these fish populations.”

— Christina Schmidt is the information and education specialist for the Wyoming Game and Fish Department’s Sheridan Region and a regular contributor to Wyoming Wildlife.
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