Illinois River Ecosystem Restoration Project: Hydrologic and Hydraulic Analyses for Large River Restoration

AbstractWood is an integral part of a river ecosystem and the number of restoration projects using log placements is increasing. Physical model tests were used to explore how the wood position and submergence level (discharge) affect wake structure, and hence the resulting habitat. We observed a von-Kármán vortex street (VS) for emergent logs placed at the channel center, while no VS formed for submerged logs, because the flow entering the wake from above the log (sweeping flow) inhibited VS formation. As a result, emergent logs placed at the channel center resulted in ten times higher turbulent kinetic energy compared to submerged logs. In addition, both spatial variation in time-mean velocity and turbulence level increased with increasing log length and decreasing submergence level. Submerged logs and logs placed at the channel side created a greater velocity deficit and a longer recirculation zone, both of which can increase the residence time in the wake and deposition of organic matter and nutrients. The results demonstrate that variation in log size and degree of submergence can be used as a tool to vary habitat suitability for different fish preferences. To maximize habitat diversity in rivers, we suggest a diverse large wood placement.

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Riverscape heterogeneity explains spatial variation in zooplankton functional evenness and biomass in a large river ecosystem

Landscape Ecology ◽

10.1007/s10980-013-9946-1 ◽

2013 ◽

Vol 29 (1) ◽

pp. 67-79 ◽

Cited By ~ 17

Author(s):

Philippe Massicotte ◽

Jean-Jacques Frenette ◽

Raphaël Proulx ◽

Bernadette Pinel-Alloul ◽

Andrea Bertolo

Keyword(s):

Spatial Variation ◽

Large River ◽

River Ecosystem ◽

Functional Evenness

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Hydrology controls recruitment of two invasive cyprinids: bigheaded carp reproduction in a navigable large river

PeerJ ◽

10.7717/peerj.3641 ◽

2017 ◽

Vol 5 ◽

pp. e3641 ◽

Cited By ~ 10

Author(s):

Daniel K. Gibson-Reinemer ◽

Levi E. Solomon ◽

Richard M. Pendleton ◽

John H. Chick ◽

Andrew F. Casper

Keyword(s):

Mississippi River ◽

Silver Carp ◽

Monitoring Program ◽

Large River ◽

Asian Carp ◽

Bighead Carp ◽

Illinois River ◽

Hypophthalmichthys Molitrix ◽

The Past ◽

Causative Factors

In the Mississippi River Basin of North America, invasive bigheaded carp (silver carpHypophthalmichthys molitrixand bighead carpH. nobilis, also referred to as Asian carp) have spread rapidly over the past several decades. In the Illinois River, an important tributary of the Upper Mississippi River, reproduction appears to be sporadic and frequently unsuccessful, yet bigheaded carp densities in this river are among the highest recorded on the continent. Understanding the causative factors behind erratic recruitment in this commercially-harvested invasive species is important for both limiting their spread and managing their harvest. We analyzed weekly catch records from 15 years of a standardized monitoring program to document the emergence of age-0 bigheaded carp in relation to environmental conditions. The appearance of age-0 fish was generally linked to hydrographic attributes, which probably serve as a cue for spawning. However, we found profound differences in the number of age-0 fish among years, which varied by as much as five orders of magnitude in successive years. The strong link between summer flooding and age-0 fish production we observed emphasizes the importance of understanding the hydrologic context in which sustained invasions occur. Despite evidence of sporadic recruitment, bigheaded carp populations in the Illinois River appear to be consistent or increasing because of particularly strong, episodic year classes.

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