Changes in the Freshwater Mussel Assemblage in the East Fork Tombigbee River, Mississippi: 1988-2011

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Byron A. Hamstead (Creator)
Appalachian State University (ASU )
Web Site:
Michael Gangloff

Abstract: The Tennessee-Tombigbee Waterway facilitates barge navigation between the Tennessee River drainage and Mobile River Basin via locks, dams, canals, and diverted streams. These alterations have destroyed habitat and isolated freshwater mussel populations in streams like the East Fork Tombigbee River. The first post-waterway mussel surveys in 1987 and 1988 reported 31 taxa. I sampled 70 sites in 2010 and 2011 and found 29 species. Though mussel richness was relatively unchanged, species composition shifted toward animals indicative of tributary systems rather than large rivers. Total abundance declined significantly. Relative abundance of 9 taxa decreased significantly; however, relative abundance increased for 11 species, 3 of them federally listed. This shift in mussel species dominance suggests that present stream habitats and/or fish hosts in the East Fork Tombigbee River are favoring smaller-bodied taxa. Yet, changes in the host fish assemblage may be responsible for the increased abundance of some sensitive mussels. Finally, I detected three non-native unionids—Quadrula quadrula, Potamilus alatus, and Potamilus ohiensis—which likely colonized the East Fork Tombigbee River from the Tennessee River drainage via the waterway. These results are among the first to document waterway-mediated shifts in mussel fauna and wide-spread assemblage changes linked to lock and dam river regulation.

Additional Information

Hamstead, B.A. (2013). Changes in the Freshwater Mussel Assemblage in the East Fork Tombigbee River, Mississippi: 1988-2011. Unpublished master’s thesis. Appalachian State University, Boone, NC.
Language: English
Date: 2013
Mussel, Tombigbee, Assemblage structure, Tennessee-Tombigbee Waterway, Lock and dam

Email this document to