Committee Chair

Schorr, Mark S.

Committee Member

Brown, Kenneth; Nelson, Charles


Dept. of Biology, Geology, and Environmental Science


College of Arts and Sciences


University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)


This thesis contains summary data from all Tennessee Aquarium Research Institute (TNARI) survey activities of freshwater mollusks within the upper Coosa River basin (UCRB) from 1998 to 2003. Survey results of 4 different TNARI studies, a total of 515 separate collections, are presented. My component of the study examined 231 sites primarily in the Coosawattee and Etowah river basins in 2002 - 2003. In addition to the 231 sites surveyed, a large database was constructed from natural history museum records to evaluate temporal changes in species richness and distribution across the UCRB. Of 43 mussel and 33 snail species reported from the UCRB, TNARI surveyors found 35 mussel and 26 snail species that remain in small, highly fragmented populations. Three snail species were not previously recorded from the UCRB. Mollusk species richness losses averaged 39% across the 8 sub-basins with reliable data. Species losses (mussels and snails combined) were greatest in the Chattooga River (63%), Etowah River (54%), Oostanaula River (49%), and Coahulla Creek (47%) basins. Species losses were lowest in the Terrapin Creek (19%), Conasauga River (31%), and Armuchee Creek (38%) basins.The number of federally-listed species was greatest in the Conasauga River Basin (6 listed, 1 candidate spp.),Holly Creek, (4 listed spp.), and in the Coosa River, Weiss Reservoir bypass (2 listed spp.).Overall, freshwater mussel ranges were reduced for 86% of the species, and species richness declined 48% across the UCRB (4 spp. extinct and 5 spp. extirpated). Freshwater gastropods also suffered dramatic range reductions (42%) and species losses (4 spp. extinct and 2 spp. extirpated). The sub-drainage with the highest CPUE for mussel species in its tributaries was Terrapin Creek, and the highest mainstem CPUE was the Oostanaula River.Mussel CPUE abundance was highest in the tributaries of Big Cedar Creek and the Coosa River, Weiss Reservoir bypass. CPUE for total snail species was highest in the mainstem Chattooga and Coosawattee rivers tributaries. In addition to the species losses in the UCRB, 4 mussel and 6 snail species are now limited to the study area. Because many remaining species are restricted to small isolated populations, further extinctions and extirpations are expected. Although quantitative habitat evaluation was not a part of this study, channel destabilization, non-point source runoff, eutrophication , dewatering of tributaries and sediment toxicity appear to be major causes of species loss. Weiss Reservoir bypass on the mainstem Coosa River has the greatest potential for mollusk species restoration, and a minimum flow restoration schedule is currently under development. Holly and Terrapin creeks have the best restoration potential of any tributary systems in the UCRB.


I thank the Tennessee Aquarium Research Institute(TNARI) and the Tennessee Aquarium for facilitating my opportunity to undertake this research; Dr. Paul Johnson for introducing me to the unique world of freshwater mollusks; Drs. Mark S. Schorr and John C. Tucker (both of the University of Tennessee at Chattanooga) for encouraging and supporting me not only during my thesis work but throughout my graduate program; Dr. George Benz (Middle Tennessee State University) for being a continuous source of feedback and greatly needed levity; Dr. Kenneth Brown (Louisiana State University) for thoughts on snail collection and editorial comments; Steven Ahlstedt (U.S. Geological Survey) for his assistance with fieldwork; Ryan Evans for his work in the Conasauga River system and advice on my thesis; Jamie Parris for preliminary work in the Coosawattee-Etowah river basins; Tim Quesenberry, Katherine Klyce, and Holly Cabrera for their assistance in the field; and Brooke Smith for her help editing maps.Many additional UTC staff deserve thanks for help given to me, including:Rebekah Bell, Virginia Cole, Dr. Charles Nelson, and Marketa Shutters. Recognizing the need for the inventory and conservation of our natural resources, agencies and organizations that have given financial support to this project are also thanked, including: the U.S. Fish and Wildlife Service, U.S. Geological Survey, The Nature Conservancy,U.S. Forest Service, Georgia Department of Natural Resources, and Tennessee Wildlife Resources Agency.


M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.




Mollusks--Effect of habitat modification on--Coosa River (Ga. and Ala.)


Environmental Monitoring

Document Type

Masters theses




ix, 318 leaves



Call Number

LB2369.2 .N682 2004