Tagged Trout to Help Wyoming Game and Fish Study Fish Movement in Encampment River
“The Encampment River is an important trout fishery and tributary to the North Platte River,” says Steve Gale, fisheries biologist. “A diversion dam built in the 1900s that is located about half a mile from the confluence of the Encampment and North Platte Rivers has most likely prevented rainbow and brown trout from migrating upstream to spawn. Our research project focuses on how providing trout passage over that structure could benefit trout populations in both rivers.”
This summer, fish biologists radio tagged 30 mature brown trout. The tags emit a signal the biologists can track to determine where the fish are moving. The tags are one component of a Game and Fish research project Laramie region biologists are conducting on the Encampment River. The brown trout were collected below the diversion dam, the radio tag was implanted in the abdomen and the fish were then released about a mile upstream of the diversion dam.
According to Gale, adult trout successfully migrating upstream into the Encampment River could increase trout numbers in that system. In addition, juvenile trout migrating downstream to the North Platte River could increase recruitment and trout abundance in the mainstem of the North Platte River. Game and Fish recognizes the importance of the diversion dam for agriculture irrigation purposes, but believes there is a way to provide fish passage over the dam, while maintaining the dam’s important function of providing irrigation and stock water.
The idea of reconnecting the Encampment and North Platte for fish isn’t a new one. A fish ladder installed in 1985 was one of the first attempts in Wyoming to facilitate upstream passage over a diversion dam. High spring flows in 1986, however, compromised the structural integrity of the ladder and it was filled in to prevent damage to the diversion dam.
Before the Game and Fish and its cooperators try to create a new way for fish to navigate the important dam, biologists wanted to collect information on potential benefits of providing fish passage upstream. That’s where the radio-tagged brown trout come in.
“We’ll locate the tagged brown trout once or twice a week into the fall,” Gale explains. “We want to be able to demonstrate where fish would spawn and overwinter if fish passage is provided at the diversion dam. In addition, by tracking their movements upstream and downstream, it could help the Game and Fish pinpoint other areas where we could work with private landowners to help fish move more freely in the Encampment River.”
The radio tags build on an earlier effort from Game and Fish to track fish movement. In 2007, 237 brown trout were tagged with orange Floy tags and released above the dam. Anglers who caught the tagged fish were asked to report the catch site to Game and Fish. The most exciting result of this project was that one tagged trout was caught near Hog Park Creek, about 23 river miles upstream from the release site.
Gale says once all the data is compiled and analyzed, information will be presented to the public and interested parties.
“We’ll use all the information we have to help us move forward with a potential fish passage structure, including input and ideas from cooperators and landowners,” he explains. “We’ve had great cooperation from the private landowners and the WYCO fishing club. They are all excellent stewards of the resource and we want to work with them as we move forward to reconnect these two rivers and help improve these important fisheries.”