Effects of Increased Commercial Navigation Traffic on Freshwater Mussels in the Upper Mississippi River: 1994 Studies.
Abstract
In 1988, the U.S. Army Engineer District, St. Louis, initiated a monitoring program to analyze the effect of commercial navigation traffic on freshwater mussels (Mollusca: Unionidae), especially the endangered Lampsilis higginsi, in the upper Mississippi River (UMR). Preliminary studies were conducted in 1988, and detailed studies were initiated in 1989 and continued until 1994. In July 1994, the last year of this study, qualitative and quantitative data (0.25 m2 total substratum samples) were collected at the following locations: Pool 24 (River Mile (RM) 299.6), Pool 17 (RM 450.4), Pool 14 (RM 504.5), Pool 12 (RM 571 A), and Pool 10 (RM 635.2, main channel). This research was funded by the U.S. Army Engineer District, St. Louis, to assess the effects of existing and projected future increased navigation traffic levels on freshwater mussels, including the endangered Higgins eye mussel, Lampsihs higginsi. A total of 26 species of bivalves were collected, including two exotic species, the Asiatic clam, Corbicula flumi-flea, and the zebra mussel, Dreissena polymorpha. During this study year, zebra mussels were still a minor component of the bivalve assemblage; density ranged from 0.27 +/- 0.13 at RM 299.6 to 8.2 +/- 1.29 individuals/m2 at RM 504.8. Based on quantitative samples at five beds, species diversity ranged from 1.78 to 2.28, and total species richness ranged from 16 to 20. The percentage of native bivalves less than 30-mm total shell length, evidence of recent recruitment, was approximately 30 at all sites except in Pool 10 at RM 635.2 where it was only 12.8. The percentage of species that were evidence of recent recruitment ranged from a low of 43.7 at RM 299.6 to 60.0 at RM 571.5.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1995
- Accession Number
- ADA304728
Entities
People
- Andrew C. Miller
- Barry S. Payne