Asian Carp Movement Patterns As a Function of Flow

The ability of bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (hereafter, Asian carp) to move long distances in relatively short time periods has been documented in the Illinois River, however, drivers of these long distance movements is largely unknown.  In addition, prior research indicated that movement rates were positively correlated with river stage.  Asian carp made long distance trips up the Illinois River when river stage increased, but never extended past Starved Rock Lock and Dam.  Immigration into the Illinois River from the Mississippi River and upstream movement of Asian carp also appeared to correspond with elevated flow in the river during spring and summer. However, Asian carp that moved upstream returned to downstream locations as water levels dropped in late summer.  To further quantify how immigration and movement rates of Asian carp change in relation to seasonal and annual changes in flow we quantified movement of 372 Asian carp in the Illinois River using acoustic telemetry during 2012 and 2013.  To relate movement to river discharge and river stage, we developed relationships between river discharge (using an Acoustic Doppler Current Profiler; ADCP) and stage height (from the USACE and USGS gaging stations).  Determining how changes in Asian carp density affect these movement rates are important considerations for forecasting population responses to removal efforts, predicting how this will affect the probability of movement toward or away from the Chicago Area Waterway System, and developing predictive models for Asian carp year class strength.