Date of Award
Spring 4-10-2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Dr. Melissa Wuellner
Committee Members
Dr. Keith Koupal
Dr. Jayne Jonas
Dr. Brian Blackwell
Keywords
Walleye, Smallmouth Bass, Fish Management, Irrigation Reservoir
Abstract
Lake McConaughy is a socially and economically important reservoir managed to provide diverse, high-quality angling opportunities. Walleye are the most frequently targeted species, although Smallmouth Bass have increased in popularity in recent years due to improvements in abundance and size structure. Walleye have been stocked annually since 1989 to support the population and have been the focus of extensive research. In contrast, Smallmouth Bass have been present for over 80 years and are self-sustaining; however, their population has not been formally evaluated since introduction.
The first objective of this study was to develop an oxytetracycline (OTC) mark retention correction factor for hatchery Walleye cohorts (2023–2025), and the second was to evaluate contributions of stocked life stages to age-1 and age-2 fish in 2024 and 2025. Marking success and retention ranged from 78% to 100%, with the 2023 cohort having the highest retention. Stage-1 fingerlings [32 – 38 mm total length (TL)] contributed more than 45% of recruits annually, whereas natural reproduction, fry (7 – 8 mm TL), and stage-2 fingerlings (50 – 63 mm TL) each contributed less than 25%.
The third objective was to assess temporal tradeoffs in Smallmouth Bass population assessment across two growing seasons. Fish were sampled from May–October in 2024 and 2025, using nighttime boat electrofishing, yielding 1,436 individuals. Catch per unit effort (CPUE) and young adult ratio (YAR) were lowest in spring and increased through summer and fall, while proportional stock density (PSD) showed the opposite trend. These results indicate spring sampling is best for assessing adult structure and trophy potential, whereas fall sampling is more effective for evaluating recruitment.
Recommended Citation
Allison, Robert D. IV, "Assessing Walleye Recruitment Via OTC Marks and Temporal Sampling Changes in Smallmouth Bass Population Structure In Lake McConaughy, Nebraska" (2026). Biology Theses, Dissertations, and Student Creative Activity. 20.
https://openspaces.unk.edu/bio-etd/20