Potential for asymmetric competition among co-inhabiting invasive Silver Carp and native shad species in the Lower Midwest

Author

Dalton D. Lebeda, Murray State UniversityFollow

Abstract

In the United States, Silver Carp are an invasive voracious planktivorous fish that are capable of competing with many native fish species. Until the last decade, very little was known about how Silver Carp would interact with native fish species or how quickly their populations would expand. In the early 2000’s, established Silver Carp populations were reported in Kentucky Lake although they were reported in the Tennessee River much earlier (1987). Kentucky Lake is the first large flood storage reservoir that has been invaded by a reproducing population of Silver Carp in the United States. To date, control measures for Silver Carp have been relatively unsuccessful despite implementation of a commercial harvest in Kentucky Lake in which hundreds of thousands of pounds of Silver Carp are harvested annually. Due to largely unsuccessful control measures, Silver Carp are likely going to be in Kentucky Lake for the long term. Therefore, it’s important to understand the ecology of Silver Carp and how they may potentially affect the native fish communities. Juvenile and adult Silver Carp and Gizzard Shad, and juvenile Threadfin Shad were collected from Kentucky Lake, Tennessee River, Ohio River, Clarks River, and Illinois River using gill netting and boat electrofishing techniques. Using stable isotope analyses, I quantified isotopic niche overlap with the goal to understand potential for competition between Silver Carp, and Gizzard Shad, and Threadfin Shad. I analyzed carbon and nitrogen ratios to calculate quantitative metrics derived from stable isotope data and to construct core isotopic niches. Results showed that, if conditions are limiting, Silver Carp are capable of competing with Gizzard Shad in Kentucky Lake, lower Tennessee River, and the Illinois River. Moreover, in Kentucky Lake, I found that juvenile Silver Carp have a higher likelihood of competing with Gizzard Shad of all age classes than their adult counterparts. I found that Silver Carp are not exploiting the same resources as Threadfin Shad. Based on my research, I recommend managers to focus on reducing juvenile Silver Carp densities and identifying and limiting opportunities for Silver Carp reproduction.

Year manuscript completed

2017

Year degree awarded

2017

Author's Keywords

Silver Carp, invasive fish, Kentucky Lake, Asian carp, competition, isotopic niche modeling

Thesis Advisor

Michael B. Flinn

Committee Member

Timothy W. Spier

Committee Member

Howard H. Whiteman

Committee Member

David S. White

Committee Member

Gary E. Stinchcomb

Document Type

Thesis

Recommended Citation

Lebeda, Dalton D., "Potential for asymmetric competition among co-inhabiting invasive Silver Carp and native shad species in the Lower Midwest" (2017). Murray State Theses and Dissertations. 69.
https://digitalcommons.murraystate.edu/etd/69