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48 NEBRASKAland • NOVEMBER 2015 needs. Although the fishes also exist throughout the Sandhills, the Keya Paha Watershed was chosen for the study because of the unique opportunity to collect data in two states. Wildlife action committees decided to give this project to a master's student. Gerdes, who was going back to school to earn her master's degree, chose this study for her research project, which would be conducted through SDSU. The university's objective was to build upon a previous student's work, Eli Felts, who updated the statuses of the species by sampling fish throughout several watersheds in South Dakota in 2011 and 2012. "What Eli noticed when he was out there, for the most part, was that the fish were few and far between, but once in a while there were lots of them," Gerdes said. "The Keya Paha Watershed, with its spring-fed streams, really stood out as an important stronghold for these species' population." However, Felts only sampled in South Dakota. It made sense to expand the study to include the streams on the Nebraska side. The Questions Furthering Felts's work, Gerdes is studying why these species of dace were abundant in certain locations and absent from others. SDSU Associate Professor Dr. Katie Bertrand hypothesized that barriers and unsuitable habitat were playing a role, and she recruited Gerdes to test those hypotheses, with the help of seven other graduate students, and dozens of undergraduate researchers in the Bertrand lab group. "In research and stream management now, 'barrier' is our sexy buzzword because a lot of streams, especially streams in the Great Plains, are 'flashy.' They are very rarely stable environments, and so most of the fish that have adapted to living in these streams have adapted to recolonizing after a catastrophic event, but in order to recolonize a place, they have to be able to move up and down the stream," Gerdes said. In the Great Plains, barriers are more often than not culverts. Generally, there is a road every single mile that cuts across a stream, and in order for that road to cross a stream, a culvert is built. "A little fish can jump about twice its body length," Gerdes said. Culverts that are placed too high are beyond the jumping capacity of these fish, hindering their ability to move up and down the stream. "Even though we have a whole stream for them to live in, if they can't get to 60 percent of it, we're slowly losing species. We want to look at barriers pretty closely and try to gain an understanding of how that is affecting population distribution." Gerdes sampled each Friday, Saturday and Sunday from mid-May through the end of August in 2013 and 2014. Her team counted and measured fish at every kilometer along the entirety of the study streams, from the headwaters to the confluence where each stream dumped into the Keya Paha River in South Dakota. "Very few projects involve sampling an entire stream. Most projects pick spots here and there, and you get a snapshot of the stream and also a snapshot in time," Gerdes said. To sample the entirety of the study streams was the university's idea to better understand how the fish were using the length of the streams, and perhaps how they moved throughout them at different times of the year. The researchers also paid special attention to habitat features. "We had information from farther north, things that the fish tended to like, certain temperatures, cool water – we knew that. We knew they like pool habitat. They also tend to coexist with beavers. But that's several states away. And our streams are different than those streams. We needed to nail down what they needed in Nebraska and South Dakota," Gerdes said. The Findings Outfitted with a backpacker electrofishing unit, nets and measurement tools, Gerdes and her team were relentless in collecting, measuring and counting fish. They kept sheets upon sheets of habitat notes. In the end, the researchers were able to locate populations of pearl and northern redbelly dace, but were unable to detect finescale dace within the three study streams. However, they did see good numbers of a hybrid between finescale and northern redbelly. These hybrid populations are typically female. Interestingly, these Northern Redbelly Dace Pearl Dace Northern Redbelly and FInescale Dace Hybrid Finescale Dace ALL FISH PHOTOS COPYRIGHT:© 2013 SOUTH DAKOTA GAME, FISH AND PARKS DEPARTMENT AND THE SOUTH DAKOTA BOARD OF REGENTS