Abstract: Mussels are extremely important biological indicators in freshwater systems. Freshwater mussel diversity can be adversely affected by anthropogenic impacts and invasive species. The influence of one invasive species, zebra mussels (Dreissenapolymorpha) have been implicated as a factor in the decline in diversity and abundance of freshwater mussel species. Mussel population distribution and D. polymorphacolonization at nine sites were studied in 2010 through 2014 field seasons near 9-Mile Island in Pool 12 of the Mississippi River. Mussels were collected by pollywoggingalong 25 meter transects of randomly selected quadrants and were examined for D. polymorpha. D. polymorphainfestation was measured on a scale of 0 to 4, depending on the amount of colonization on the freshwater mussel. Live mussels (2,628) and recaptured mussels (n = 297) were measured for shell length, width, and height, which were used to ages of the live mussels. Mussel densities were probed to determine if differences occurred due to an increased growth rates or longer lifespan. A total of 2,628 mussels, representing 21 species, were cataloged. The most prevalent mussel species were Threeridge(Amblemaplicata; n=1420), which had D. polymorphacolonization of 20.4%, Wabash Pigtoe(Fusconaiaflava; n=953), which had a D. polymorphacolonization of 8.2%, ThreehornWartyback(Obliquariareflexa; n=333), which had D. polymorphacolonization of 16.8%, and Plain Pocketbook (Lampsiliscardium; n=183), which had D. polymorphacolonization of 23.4%. Implications of D. polymorphacolonization and human impacts in pool 12 and other pools of the Mississippi River will be discussed.
Citation: Skopek, Jenna L., Hoffman, Adam.R., Marr, Shelby L., Call, Daniel J., & Malon, Michael J. “Interspecies Variations in Growth Rate and Zebra Mussel (Dreissena polymorpha) Among Native Freshwater Mussels in Pool 12 of the Mississippi River.” Poster presentation for the Chlapaty Research Fellowship Program, University of Dubuque, 2014.