Semester of Graduation
May 2026
Degree
Master of Science (MS)
Department
Renewable Natural Resources
Document Type
Thesis
Abstract
Since their introduction in the 1970s, invasive Silver Carp (Hypophthalmichthys molitrix) have had significant impacts on aquatic ecosystems throughout the Mississippi River watershed. Anthropogenic factors such as modifications to stream connectivity and climate change-driven shifts in hydrology and temperature have facilitated rapid expansion of these highly invasive fish. Despite their spread in Louisiana waterbodies, trophic effects of Silver Carp on native species and food web dynamics in the lower Mississippi River (LMR) remain poorly understood. As efficient planktivores, Silver Carp directly compete with native planktivorous species, potentially altering abundance and composition of forage available to both native planktivores and piscivores. Additionally, their grazing activities can disrupt nutrient cycling, water clarity, and primary production, leading to ecosystem imbalances in sensitive habitats. In chapter 1, I used stable isotopes from fish collected in fall 2022 through fall 2024 to investigate trophic relationships among Silver Carp and several native fishes commonly found throughout southeastern watersheds. Results indicated significant trophic overlap between Silver Carp and Bigmouth Buffalo (Ictiobus cyprinellus), Gizzard Shad (Dorosoma cepedianum), and Striped Mullet (Mugil cephalus). In chapter 2, I compared body condition of Silver Carp from inland and coastal Louisiana with previous data from studies conducted in the upper and middle Mississippi River regions. Results showed Silver Carp were significantly longer than conspecifics from other regions, suggesting increased consumption and/or feeding efficiency in these subtropical systems. These results underscore the urgent need to evaluate their trophic interactions, food web impacts, and broader ecological impacts on native aquatic communities. Developing effective management strategies is crucial to mitigating ecological disruptions caused by Silver Carp and maintaining biodiversity and ecosystem health in southern river drainages.
Date
1-17-2026
Recommended Citation
Pentz, Bailey G., "Trophic Relationships Among Invasive Silver Carp (Hypophthalmichthys molitrix) and Native Fishes in the Lower Mississippi Alluvial Valley" (2026). LSU Master's Theses. 6274.
https://repository.lsu.edu/gradschool_theses/6274
Committee Chair
Kaller, Michael D.
Included in
Natural Resources and Conservation Commons, Natural Resources Management and Policy Commons