Potential Impact of Asian Carps in the Great Lakes: An IBM Community Model Approach

Bighead and silver carps (AC) pose a significant threat to Great Lakes food webs and fisheries.  The potential for AC to invade the Great Lakes is high, but the likelihood of establishment and impacts on Great Lakes ecosystems remain unknown.  We developed a spatially-explicit, bioenergetics-based model of Asian carp individuals (IBM) to predict the likelihood of AC establishment and impact on native fishes in nearshore and offshore habitats of Lake Huron.  We modeled daily consumption, growth, survival, reproduction and movement of AC individuals and key fish species including walleye, yellow perch, rainbow smelt, lake trout, and round goby.  We also modeled total biomass of lower trophic levels (algae, zooplankton, benthos).  We took a two-step approach for simulating  AC establishment and impact.  First, we determined the number of individuals needed to establish AC populations in Lake Huron by altering the number of AC individuals released.  Second, we determined potential AC impacts on the Lake Huron fish community under a variety of scenarios, including varying densities of AC and with and without climate change.  In the future, we will configure the model to simulate AC impacts on nearshore and offshore habitats and fish communities of Lake Michigan and Lake Erie.