Title

Using Stable Isotope Analysis to Quantify Isotopic Niche Overlap between Silver Carp and Gizzard Shad

List all Project Mentors & Advisor(s)

Dr. Michael B. Flinn; Ph.D

Presentation Format

Event

Abstract/Description

Kentucky Lake is the largest impoundment east of the Mississippi River and is located on the Tennessee River in western Kentucky. The reservoir has a diverse fishery consisting of many fish species that prey upon native planktivorous Gizzard Shad Dorosoma cepedianum and Threadfin Shad D. petenense. Silver Carp Hypophthalmichthys molitrix are an invasive planktivorous fish species that invaded Kentucky Lake in 2004 and data suggests successful establishment and a reproducing population. Previous studies on the Illinois River have suggested that Silver Carp are competing for prey resources with native fish species including Gizzard Shad. Therefore, diet overlap and competition between Silver Carp and Gizzard Shad in Kentucky Lake is a major concern to biologists and fishermen. For our study, we used δ15N and δ13C isotopic signatures to perform niche analysis and to quantify isotopic niche overlap. Fish were sampled using: cast nets, gill nets, and boat electrofishing. We found non-significant isotopic niche overlap between Silver Carp and Gizzard Shad in Kentucky Lake. In conclusion, Silver Carp and Gizzard Shad appear to have a low potential for competition. However, if Silver Carp populations increase, and resources become depleted, then the potential for competition may increase and result in ecosystem effects.

Location

Barkley Room, Curris Center

Start Date

20-4-2016 9:00 AM

End Date

20-4-2016 4:00 PM

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Apr 20th, 9:00 AM Apr 20th, 4:00 PM

Using Stable Isotope Analysis to Quantify Isotopic Niche Overlap between Silver Carp and Gizzard Shad

Barkley Room, Curris Center

Kentucky Lake is the largest impoundment east of the Mississippi River and is located on the Tennessee River in western Kentucky. The reservoir has a diverse fishery consisting of many fish species that prey upon native planktivorous Gizzard Shad Dorosoma cepedianum and Threadfin Shad D. petenense. Silver Carp Hypophthalmichthys molitrix are an invasive planktivorous fish species that invaded Kentucky Lake in 2004 and data suggests successful establishment and a reproducing population. Previous studies on the Illinois River have suggested that Silver Carp are competing for prey resources with native fish species including Gizzard Shad. Therefore, diet overlap and competition between Silver Carp and Gizzard Shad in Kentucky Lake is a major concern to biologists and fishermen. For our study, we used δ15N and δ13C isotopic signatures to perform niche analysis and to quantify isotopic niche overlap. Fish were sampled using: cast nets, gill nets, and boat electrofishing. We found non-significant isotopic niche overlap between Silver Carp and Gizzard Shad in Kentucky Lake. In conclusion, Silver Carp and Gizzard Shad appear to have a low potential for competition. However, if Silver Carp populations increase, and resources become depleted, then the potential for competition may increase and result in ecosystem effects.