2.1 | Study Area
The Upper Mississippi River extends from the Mississippi River headwaters in Minnesota to its confluence with the Missouri River just north of St. Louis, MO. This portion of the river is impounded by 29 locks and dams and highly channelized to allow for barge traffic. Our study focuses on pools 18 to 20 from just upstream of the Iowa River confluence to just downstream of the Des Moines River confluence (Figure 1). Along this reach, there are three main tributaries: the Iowa River on pool 18, the Skunk River on pool 19, and the Des Moines River on pool 20 (Figure 1). These locations represent the furthest upstream extent of most bigheaded carp reproduction in the Upper Mississippi River (Camacho et al., 2023; La Hood et al., 2023; Larson et al., 2017), with some evidence of reproduction up to Pool 16 (Larson et al., 2017).