Silver Carp Hypophthalmichthys molitrix broad movement patterns and dispersal dynamics in the upper Mississippi River

Abstract

Rivers are important movement corridors for fishes that allow for population connectivity. Within the upper Mississippi River Basin, invasive Silver Carp ( Hypophthalmichthys molitrix ) use tributaries including the Des Moines, Iowa, and Cedar rivers; however, the extent Silver Carp move and intermix among these systems and pools of the upper Mississippi River (UMR) is largely unknown. We used acoustic telemetry and multistate models to (1) identify individual and spatial variability in movement strategies, (2) use survival and transition probability estimates to evaluate population dynamics and connectivity, and (3) evaluate the influence of temporal and environmental variables on survival and transition probabilities. Weekly transition probabilities generally increased with discharge and ranged between 0.01 from UMR Pool 20 to outside the study area at 575 m 3 /s to 0.75 from UMR Pool 18 to outside the study area at 7200 m 3 /s. Survival decreased as temperature increased from 0 to 30 °C and was higher in tributaries than mainstem pools correlated with lower discharge. Overall, Silver Carp displayed diverse movement strategies with high connectivity that can inform invasive species management strategies.