Effects of a Gated Dam on the Upstream Migration of Asian Carp in the Illinois River

Invasive Bighead Carp (Hypophthalmichthys nobilis) and Silver Carp (H. molitrix),hereafter, Asian Carp (AC),  pose a major threat to the Great Lakes ecosystem as they advance toward Lake Michigan via the Illinois River. However, a series of dams may deter their upstream movement; yet, limited information exists regarding these dams as inhibitors of AC movement. Starved Rock Lock and Dam (SRLD) is the most downstream gated dam on the Illinois River, therefore presenting the first navigation challenge for upstream migrating AC. Since 2012, five acoustic receivers near SRLD detected successful upstream passage by only three AC (of over 900 tagged fish in the river). Because these data indicate SRLD may act as a barrier to AC movement, our objective was to further investigate the permeability of SRLD to AC migration. We increased our receiver network around SRLD and tagged an additional 100 AC downstream of SRLD.  This information will allow us to relate AC movements to environmental variables and location of successful or attempted passages, which will be particularly important for managing AC and reducing their upstream movement at other gated dams along the Illinois and Mississippi Rivers.