Post Flood Rotenone Sampling of Isolated Pools on the Floodplain of Upper Channelized Missouri River

The Missouri River Flood of 2011 provided floodplain inundation and connectivity that has been rare if not non-existent on the upper channelized segment of the river. The timing and duration of the event was similar to discharges experienced before construction of the Missouri River Reservoir System. The expected ecological benefits of flooding in large floodplain river systems include increased reproduction of fish. After the flood receded we sampled five isolated floodplain water bodies with the fish toxicant rotenone to assess reproductive success, biomass and species richness. Samples were composed almost entirely of young of the year fish. Richness ranged from 18 to 30 species. Family richness ranged from 8 to 11. Biomass ranged from 30.8 kg/h to 97.3kg/h. Biomass was dominated by big river habitat generalists, gizzard shad, buffalos and carp but channel catfish, largemouth bass, yellow perch and northern pike were common. Grass pickerel, which had not been sampled previously in Western Iowa, were collected at two sites.