Evaluating Gizzard Shad Dorosoma cepedianum Populations in two Kentucky Reservoirs Recently Invaded with Silver Carp Hypopthalmichthys molitrix

Gizzard Shad Dorosoma cepedianum are an ecologically important fish species found in many reservoirs throughout the southeastern United States such as Kentucky Lake and Lake Barkley. One current challenge that Gizzard Shad may face in these two reservoirs is competition with the invasive Silver Carp Hypophthalmichthys molitrix. However, quantifying the impacts of this competition may be difficult because of limited baseline population data for Gizzard Shad in these two reservoirs. The objective of this study is to describe size structure, condition, age, growth, mortality, and spawning potential of these two populations. Gizzard Shad were collected by boat electrofishing and surface trawling in cove and main channel locations during the growing season in 2021. All shad were enumerated and measured, and sagittal otoliths were used to age Gizzard Shad collected in the fall. Size structure, condition, age structure, growth rates, mortality, and spawning potential of Gizzard Shad were compared between these two reservoirs and to other southern reservoirs which do not contain Silver Carp. Results from this study will be used as a baseline for future monitoring of Gizzard Shad populations in Kentucky Lake and Lake Barkley and hopefully will reveal the impacts of invasive carp on Gizzard Shad