Cooperative Fish and Wildlife Research Units Program: Iowa
Education, Research and Technical Assistance for Managing Our Natural Resources

Silver Carp (Hypophthalmichthys molotrix) and Bighead Carp (H. nobilis), collectively Asian carp, are invasive species spreading throughout the Upper Mississippi River Basin (UMRB). Like many invasive species, Asian carp have negative economic and ecological impacts. The Upper Mississippi River (UMR) is divided by a series of lock and dams, creating lotic habitat below dams followed by pooled, lentic habitat before the next dam. Pooled sections of the UMR limit reproductive success and inhibit expansion. Despite the lack of optimal reproductive habitat within the UMR, tributaries of the UMRB contain stretches of free-flowing, unimpounded sections where reproduction has been documented in the Des Moines, Iowa and Skunk rivers. Adult densities within the UMR bordering Iowa are highest below Lock and Dam 19 (LD 19) near Keokuk. Although presence above LD 19 is not uncommon, abundance decreases progressively upstream. The objectives of this project are to (1) evaluate stock-recruitment trends present within the UMR where both adult stock and recruits have been sampled (Des Moines, Skunk, and Iowa Rivers) and (2) to assess accuracy of random forest models previously constructed to identify fish species based on egg morphometrics within the UMRB.