Southern Illinois University Carbondale OpenSIUC Reports Fisheries and Illinois Aquaculture Center 11-2007 Swan Lake Habitat Rehabilitation and Enhancement Project: Post-Project Monitoring of Water Quality, Sedimentation, Vegetation, Invertebrates, Fish Communities, Fish Movement, and Waterbirds James E. Garvey Southern Illinois University Carbondale John H. Chick Illinois Natural History Survey Michael W. Eichholz Southern Illinois University Carbondale Greg Conover U.S. Fish and Wildlife Service Ronald C. Brooks Southern Illinois University Carbondale Follow this and additional works at: http://opensiuc.lib.siu.edu/fiaq_reports Final Report. Prepared for the St. Louis District, U.S. Army Corps of Engineers. Recommended Citation Garvey, James E.; Chick, John H.; Eichholz, Michael W.; Conover, Greg; and Brooks, Ronald C., "Swan Lake Habitat Rehabilitation and Enhancement Project: Post-Project Monitoring of Water Quality, Sedimentation, Vegetation, Invertebrates, Fish Communities, Fish Movement, and Waterbirds" (2007). Reports. Paper 1. http://opensiuc.lib.siu.edu/fiaq_reports/1 This Article is brought to you for free and open access by the Fisheries and Illinois Aquaculture Center at OpenSIUC. It has been accepted for inclusion in Reports by an authorized administrator of OpenSIUC. For more information, please contact [email protected]. Swan Lake Habitat Rehabilitation and Enhancement Project: Post-Project Monitoring of Water Quality, Sedimentation, Vegetation, Invertebrates, Fish Communities, Fish Movement, and Waterbirds Principle Investigators: James E. Garvey1, John H. Chick2, Michael W. Eichholz3, Greg Conover4, Ronald C. Brooks1 Graduate Research Assistants: Laura Csoboth1, Kelly DeGrandchamp1, Douglas Schultz1, Darin Grulkowski3, Randy Smith3, Thomas R. Timmerman2 Research Assistants: Chad R. Dolan2, James T. Lamer2, Erin Hotchkiss3, Brett Tevini3, Colby Wrasse4, Nathan Caswell4, Darrin L. Martin1 1Fisheries & Illinois Aquaculture Center and Department of Zoology Southern Illinois University at Carbondale Carbondale, IL 62901-6511 2Great Rivers Field Station Illinois Natural History Survey 8450 Montclair Ave Brighton, IL 62002 3Cooperative Wildlife Research Lab Southern Illinois University, Carbondale, IL 62901-6504 4U.S. Fish and Wildlife Service Carterville Fishery Resources Office Marion, Illinois Prepared for the St. Louis District, U.S. Army Corps of Engineers FINAL REPORT NOVEMBER 2007 1 TABLE OF CONTENTS Section 1: Executive Summary ..........................................................................................4 Section 2: Monitoring .......................................................................................................19 Summary ........................................................................................20 Introduction ....................................................................................23 Water Quality .................................................................................27 Sediment Hardness.........................................................................49 Sediment Resuspension .................................................................56 Aquatic Vegetation ........................................................................67 Macroinvertebrates ........................................................................76 Fish .................................................................................................85 Section 3: Fish Habitat Use and Movement ...................................................................107 Fish Movement ............................................................................108 Channel Use of Lower Swan .......................................................152 Asian Carp Habitat and Movement ..............................................182 Section 4: Fish Reproduction ..........................................................................................216 Drifting Lateral Connectivity .......................................................216 Comparison of Backwaters ..........................................................253 Asian Carp Reproduction .............................................................292 Section 5: Fish Demographics ........................................................................................317 Pre-Post HREP Comparison ........................................................317 Asian Carp Populations ................................................................372 Section 6: Waterbirds and Food Availability ..................................................................391 Macroinvertebrate Prey ................................................................392 Waterfowl Abundance and Behavior ...........................................413 Waterfowl Diet Selection .............................................................444 Appendix A: Invertebrate Drift and Lateral Connectivity ..............................................500 Appendix B: Foraging Habitat ........................................................................................515 2 ACKNOWLEDGEMENTS We thank the cast of technicians and student workers that were involved in this research. Comments and direction by staff of the Two Rivers National Wildlife Refuge including Ken Dalrymple and John Mabery as well as others within the U.S. Fish and Wildlife Service, notably Karen Westphall and Dick Steinbach, were greatly appreciated. The advice and support of many other individuals including Eric Laux, Tim George, Brian Markert, and Rob Maher were invaluable. Robert Sheehan was involved in the early design of this research and left us too soon. Funding was provided by the Environmental Management Program through the direction of the St. Louis District of the U.S. Army Corps of Engineers. 3 SECTION 1: EXECUTIVE SUMMARY Rivers throughout the world are continually being modified by humans for many uses including navigation, water supply, agriculture, and flood control. One such river region that has felt the marked impact of human activities is the ecologically and economically important confluence area of the Illinois and Mississippi Rivers. This area contains a diverse complex of backwaters, supports recreational fishing and hunting, contributes to downstream river productivity, sustains a commercial fishery, and promotes biological diversity near a major metropolitan area. We were tasked with evaluating the response of a major 1,100-ha Illinois River backwater, Swan Lake (Figure 1) of the Two Rivers National Wildlife Refuge (NWR), to its rehabilitation as an US Army Corps of Engineer’s Habitat Rehabilitation and Enhancement Project (HREP) authorized through the Environmental Management Program (EMP) of the Water Resources Development Act (WRDA). Before European settlement of the confluence region, most of Swan Lake was at a higher elevation than the Illinois River during its base flow, allowing regular spring flooding and summer drainage plus drying (Heitmeyer and Westphall 2007). The advent of agriculture in the region increased sediment loading in the river basin. Further, the construction of Lock and Dam 26 downstream across the Mississippi River in 1938 raised the summer river elevation by about 9 feet, increasing the surface area of Swan Lake by six times its historic extent. Although aquatic (but not terrestrial) biological production within the river area temporarily increased following inundation, lost vegetation diversity, reduced seasonal pulses in primary and secondary production, increased sedimentation, and declining depth rapidly began to Executive Summary 4 compromise the backwater’s ecosystem services. By the late 1980s, Swan Lake was identified as a candidate for rehabilitation through the EMP to mitigate these environmental insults. In the early 1990s, baseline monitoring data were collected in Swan Lake before the HREP so that responses of water quality, vegetation, invertebrates, fish, and waterbirds could be compared to pre-project conditions. Following this monitoring effort, the northernmost portion of the backwater (i.e., Upper Swan Lake plus Fuller Lake) was leveed through the HREP, with management orchestrated by the State of Illinois primarily as a moist-soil unit. The lower portion of Swan Lake was divided by the HREP into two large compartments by a cross levee (Figure 1). These compartments also were isolated from the river by a levee to prevent regular inundation and thus reduce sediment loading. Each compartment (hereafter, Middle Swan [MS] and Lower Swan [LS]) could be connected to the river by a short, narrow (5-m wide) channel with a stop-log, water–control structure (Figure 1). Islands were constructed across the compartments to reduce waves caused by wind across the lake fetch. In LS, deepwater areas were excavated at the base of the river levee to provide fish overwintering habitat. Water levels within MS and LS could be lowered by closing the water-control structures and redirecting water back into the river via a pump within each compartment. Middle Swan and LS are managed under the direction of the Two Rivers NWR. Following the construction phase of the HREP in summer 2002, flocculent sediments in MS and LS were consolidated by draining the compartments and allowing them to dry. During 2003- 2005, MS was again partially dewatered each summer and flooded during fall through spring. In contrast, LS was reconnected to the river via the open water control structure and its associated Executive Summary 5 channel. During