Effects of Increased Commercial Navigation Traffic on Freshwater Mussels in the Upper Mississippi River: Ten-Year Evaluation

摘要

In the late 198Os the U.S. Army Engineer District, St. Louis, requested that the U.S. Army Engineer Waterways Experiment Station, now part of the Engineer Research and Development Center, in Vicksburg, MS, conduct studies on the physical and biological effects of commercial navigation traffic at five historically prominent mussel beds in the upper Mississippi River (UMR). The purpose was to assess effects of increased navigation traffic caused by the newly completed Melvin Price Locks and Dam at Alton, IL. Studies were initiated in 1989 and conducted annually until 1994 when they were to be done every fifth year until 2040. This report describes results of studies conducted in 1999 at three of the mussel beds located in Pool 10 (River Mile (RM) 635), Pool 14 (RM 504.8), and Pool 24 (PM 299.6). In previous years, mussel beds at RM 450.4 (Pool 17) and RM 571.5 (Pool 12) were also studied. Because of recent concern over effects of zebra mussels (Dreissenapolymorpha) on freshwater mussels, data collected in 2000 and 2001 on this species have also been included. In 1999, 26 species of bivalves, including the Asian clam, Corbiculaflurninea. were collected at the three beds in the UMR using qualitative methods. Overall, the fauna was dominated by Amblemaplicata; this species comprised more than 60 and 40 percent of the fauna in Pools 10 and 14, respectively. Ellipsaria lineolata was the dominant freshwater mussel at the mussel bed in Pool 24. The endangered Lainpsilis higginsi was found in Pool 10 (1.72 percent of the assemblage) and Pool 14 (2.44 percent of the assemblage). It was not found in Pool 24, which is outside its range.