Fluvial processes and passive rehabilitation of the Lisbon bottom side-channel chute, Lower Missouri River

Abstract

Multiple large floods in 1993-1997 on the Lower Missouri River carved a side-channel chute through the river bottom at Lisbon, Missouri. Although similar in some respects to engineered side-channel chutes designed for habitat rehabilitation projects, the Lisbon Bottom chute has been unique in that it was allowed to evolve for more than four years with minimal stabilization. During the wet years, 1996-1999, the chute was subjected to abnormally high discharges and passed as much as 20% of the total discharge of the Missouri River. Relatively unrestrained fluvial processes during this time created a wide channel with highly diverse habitats. The upper one-half of the chute established a shallow, braided channel morphology similar to the pre-managed Missouri River. The lower half established a dynamically migrating, single-thread channel, and an incipient flood plain. Compared to the adjacent navigation channel, the chute established substantial areas of shallow, slow-velocity aquatic habitat that is considered to be in short supply in the present-day Lower Missouri River. The shortterm biological benefits have been mixed: the chute has fewer waterbird and benthic macroinvertebrate taxa than adjacent riverine habitats, but greater numbers of fish species compared to the navigation channel.

Patterns of fish diversity in a mainstem Missouri River reservoir and associated delta in South Dakota and Nebraska, USA

“…However, many researchers agree that habitat diversity and a complex riverine landscape correspond with higher ecological productivity and fish species diversity in the Missouri River (Morris et al, 1968;Funk and Robinson, 1974;Schmulbach et al, 1975;Kallemeyn and Novotny, 1977;Groen and Schmulbach, 1978;Hesse et al, 1988;Brown and Coon, 1994;Galat et al, 1998;Fisher and Willis, 2000;Welker and Scarnecchia, 2003;Dieterman and Galat, 2004). We contend that reservoir deltas may play a role in Missouri River fish conservation and management by increasing aquatic habitat diversity via passive rehabilitation (sensu Jacobson et al, 2001) because the natural processes of sediment transport and habitat formation are present and dynamic in the delta. As a result, reservoir deltas may increase management options and provide unique opportunities for studies of ecological processes.…”

“…high sediment loads, high width-depth ratios, abundant sand substrate, several wetlands and aquatic vegetation) and habitat conditions are seemingly consistent with recommendations for habitat restoration elsewhere along the Missouri River (Harberg et al, 1993;Hesse and Sheets, 1993;Latka et al, 1993). Further, studies have shown that Missouri River reaches with braided river channels and a diversity of aquatic habitats within the floodplain have diverse fish communities (Schmulbach et al, 1975;Kallemeyn and Novotny, 1977;Jacobson et al, 2001) and are superior for sport fish production as compared to channelized and/or modified reaches (Groen and Schmulbach, 1978). Such reaches also support more diverse invertebrate communities (Morris et al, 1968).…”

Are restored side channels sustainable aquatic habitat features? Predicting the potential persistence of side channels as aquatic habitats based on their fine sedimentation dynamics

“…However, designs for side channel restoration projects are poorly informed by theory or empirical observations, despite massive investments (Jacobson et al, 2004;Shields et al, 2009). Only a few studies have reported detailed hydromorphological responses of side channel restoration (Jacobson et al, 2001(Jacobson et al, , 2004Amoros et al, 2005). Consequently, the development of practical predictive tools to promote effective side channel restoration remains a major challenge.…”

Fish community response to habitat variables in two restored side channels of the lower Platte River, Nebraska

“…The ecological outcomes of rehabilitated floodplain habitats vary depending on conditions within them. Jacobson, Laustrup, and Chapman () found higher species richness in a side channel to the Missouri River that had slower and shallower water than the main‐stem river. King, Humphries, and Lake () found fish recruitment in floodplain habitats of the Ovens River was not simply correlated to an inundation event, but other hydrological variables and water temperature.…”