Fish Community Response to the Establishment and Expansion of Asian Carp along a Spatio-Temporal Gradient

Long-term, spatially extensive datasets are critically important for understanding broad-scale ecological changes. In the 1950s, Illinois Natural History Survey scientists initiated a standardized electrofishing sampling program (Long-Term ElectroFishing - LTEF) on the Illinois River Waterway (IRW). This monitoring program spans six decades and has documented not only the effects of pervasive degradation, but also the promising recovery of a fish community following the passage of environmental regulations during the 1970s. However, as a heavily modified river system that connects the Mississippi River watershed to the Great Lakes watershed, the IRW is a conduit for the movement of invasive species between watersheds. The most-recent – and perhaps most-feared – invasives are Asian carps, which threaten the Great Lakes themselves, and countless highly productive miles of connected rivers as well. Using the unparalleled spatio-temporal record of the LTEF program, we have documented the Asian carps’ march up the IRW toward the Great Lakes. We present an analysis of an ongoing 60-year, watershed-scale dataset, including ebbs and flows in Asian carp CPUE, condition, and chronic effects on the fish community. Our program provides fish community data prior to the invasion and at every step as it happens. Our objective is to provide a better understanding of how Asian carps have affected fish communities throughout the IRW. We believe these findings may provide indications of how Asian carp populations can become established and grow in novel habitats.