Date of Award:

8-2026

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Watershed Sciences

Committee Chair(s)

Timothy E. Walsworth

Committee

Timothy E. Walsworth

Committee

Chad Teal

Committee

Erica Stuber

Abstract

Native fish species around the world have declined due to habitat loss, habitat fragmentation, and the spread of non-native species. Because these problems often happen at the same time and interact, recovery efforts can stall unless they address all of the factors limiting a species' comeback. The June sucker (Chasmistes liorus), native only to Utah Lake, UT, has declined for many of these reasons, though its recovery effort has made significant progress due in large part to a successful hatchery program. Yet, the recovery efforts have not yet been able to establish a self-sustaining population in Utah Lake, suggesting that young wild-born fish are not advancing to the next stage. Thus, understanding what is happening at these early stages may help wildlife managers overcome this issue. In my first chapter, I examined how individual fish contribute to variation in spawning migration timing each year, using 17 years of tracking data and a statistical model. I found that roughly half of the variation in migration timing comes from consistent differences between individual fish. I also found that fish began migrating earlier as they aged, males arrived before females, and where a fish originally came from also influenced when it moved. In my second chapter, I examined how June sucker and nonnative fish use habitats in a restored section of the Provo River Delta. I found that the dominant species of fish found across the habitat changed with month, the type of aquatic plants present, substrate, and water temperature. For each species, I found their presence depended on the month, the plant types present, and the temperature, while the number of fish found depended mainly on the month and substrate. Despite being a primary driver for the restoration of the Provo River Delta, juvenile June sucker were a very small percentage of the fish caught, suggesting that the nonnative fish species may be limiting June sucker use of the habitat. Thus, efforts to control the impacts of the nonnative fishes may be needed to allow the June sucker to realize the full benefits of the restored habitat.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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