Reducing the Effects of Maintenance Dredging on Freshwater Mussels in the Alabama River, Alabama
Abstract
In September 1998, detailed studies of freshwater mussels (Family: Unionidae) were conducted at four mussel beds in the Alabama River, located at River Miles (RM) 20.2-20.4, 30.1-30.4,121.8-122.6, and 124.4-124.9. Studies were done at the request of the U.S. Army Engineer District, Mobile, to obtain information concerning recertification of the operations and maintenance plan and the previously approved maintenance dredging and disposal. Approximately 1,500 mussels representing 13 species were collected using quantitative methods. Fusconaia ebena (ebony shell), Quadrula asperata (Alabama orb), and Obliquaria reflexa (threehorn wartyback) were most abundant and represented 76.2, 12.6, and 5.7 percent of the collection, respectively. Overall species diversity (Shannon's diversity index, H') for each mussel bed, based on 20, 0.25-m2 samples, ranged from a low of 0.81 at RM 124.4 to a high of 1.63 at RM 20.2. Density at the most downriver two beds was low (less than 25 individuals/m2), whereas at the two upriver beds it was greater than 100 individuals/m2. No Federally listed endangered or threatened species were collected, although a fresh-dead inflated heelsplitter (Potamilus inflatus), listed as threatened, was collected in 1998 by another worker at the bed located between RM 20.2 and 20.4. Recruitment rates were similar at all locations; evidence of recent recruitment was found for F. ebena, Fusconaia cerina (Gulf pigtoe), 0. reflexa, Truncilla donaciformis (fawnsfoot), Lampsilis ornata (southern pocketbook), Ellipsaria lineolata (butterfly), and Q. asperata. The exact location of each bed was mapped using a global positioning system.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2000
- Accession Number
- ADA379934
Entities
People
- Andrew C. Miller
Organizations
- Engineer Research and Development Center