Date of this Version
The U.S. Army Corps of Engineers (USACE) Upper Mississippi River-Illinois Waterway System (UMR-IWW) Navigation Study was completed in September 2004 after more than 14 years of intensive study and evaluation of the navigation improvement and ecological restoration needs for the UMR-IWW system for the years 2000-2050. The final recommendation included a program of incremental implementation and comprehensive adaptive management to achieve the dual purposes of ensuring a sustainable natural ecosystem and navigation system. The program was initiated in 2005 as the working title of Upper Mississippi River (UMR) System Navigation and Ecosystem Sustainability Program (NESP) (USACE 2006).
A series of 29 navigation locks and dams is used to manage water levels on 1,033 km of the northern reach of the UMR. Dams impose at least partial barriers to passage of the 143 indigenous fishes (Pitlo et al. 1995) in the UMR (Fremling et al. 1989). Improving upriver fish passage through the navigation dams is recognized as a way to manage the UMR toward a more sustainable river ecosystem (UMRCC 2001; Wilcox et al. 2004). Under the NESP, an interdisciplinary and interagency Navigation Study Fish Passage Team was formed to study fish passage opportunities and alternatives at navigation dams on the UMR (Wilcox et al. 2004).
The Fish Passage Team selected Mel Price Lock and Dam near Alton, Illinois as the location for one of the first fish passage projects on the UMR navigation system. The objective of this study was to determine the species composition of fish aggregations identified through hydroacoustics below Mel Price Lock and Dam. This primarily qualitative study took place in 2005 and 2006, and was accomplished through cooperation with the USACE M/V Boyer. Prior to each sampling event, the M/V Boyer conducted hydroacoustic surveys at the dam to locate fish aggregations. These aggregations were then sampled to determine which species were being located by the M/V Boyer.
This report is a synopsis of our findings from May 2005 through June 2006. The tailwater area of Mel Price Lock and Dam was broken down into three general areas that were repeatedly sampled throughout the year. Results and discussion for each area are treated separately.