Martin J. Hamel
Mark A. Pegg
Date of this Version
Werner, J. P. 2020. Population demographics, distribution, and environmental history of Asian carp in a great plains river. Master's theses. University of Nebraska-Lincoln.
Silver Carp Hypophthalmichthys molitrix, Bighead Carp H. nobilis, and Black Carp Mylopharyngodon piceus, collectively known as Asian carp, are a group of invasive fishes in the U.S.A. that have garnered much attention over the last couple decades. Most research devoted to this group of fishes has been focused in the Mississippi River basin with little investigation in the Missouri River drainage, particularly in tributary systems. The Kansas River is a major tributary to the Missouri River that has multiple anthropogenic barriers creating varying levels of connectivity within the Kansas River itself, and with the Missouri River. Information on various life-history traits of Asian carp are needed before a management plan can be formed. Here, we investigated 1) population demographics, 2) distribution with environmental DNA (eDNA), and 3) environmental history using otolith microchemistry of Asian carp in the lower Kansas River. Silver Carp exhibited spatiotemporal differences in population demographics. Individuals captured above the lowermost barrier had longer lengths-at-age, longer total lengths, and occurred at lower relative abundance than individuals captured below the barrier. No Silver Carp nor Bighead Carp were detected above the second barrier on the river with physical sampling or with the eDNA assay. However, Black Carp were detected near the confluence with the Missouri River with the eDNA analysis. Otolith microchemistry results indicated the population of Silver Carp in the Kansas River is comprised of predominantly residential individuals. Few carp exhibited natal origin signatures from the Missouri River. Transient individuals within the population exhibited short durations of signatures indicative of the Missouri River, suggesting that movements into the Missouri River are brief. These results highlight the importance of tributary habitat for Asian carp in the Missouri River drainage. Management efforts within the Kansas River could be an effective means of population control and mitigating secondary introductions. Additionally, management efforts focused in particular reaches of the Kansas River could affect the greater Missouri River population.
Advisers: Martin J. Hamel and Mark A. Pegg