Movement patterns of freshwater mussels following relocation: a case study of Potamilus capax and Quadrula quadrula in an Arkansas drainage ditch

A.D. Christian^1,2, A.J. Peck¹, J.L. Farris¹, and J.L. Harris².¹Department of Environmental Sciences, Arkansas State University, State University, Arkansas 72467, ²Department of Biological Sciences, Arkansas State University, State University, Arkansas 72467

As a component of a larger study examining mussel relocation practices, movement patterns of Potamilus capax and Quadrula quadrula were followed from October 2005 to January 2006. Resident and relocated mussels were given a unique number, etched on the shell, and a passive integrated transmitter (PIT tag) was attached to each mussel. Subsequently, radio transmitters were attached to the posterior slope of native (n = 16) and relocated (n = 12) P. capax. Initial coordinates were established using GPS technology and updated monthly. Movement, measured as differences between coordinates, was analyzed and plotted in GIS. Results indicate little to no movement for Q. quadrula and short movements (< 15 m) for P. capax. This study will be continued throughout a one year period to determine the potential movement ranges of P. capax and Q. quadrula. Though this study is ongoing, greater movement is expected in the mid-spring through late summer associated with reproduction and changing micro-habitat conditions. A period of relative dormancy is predicted during late fall and winter due to reduced primary production and water temperature. Information gained from this study will assist in the design of mitigation practices associated with in-stream disturbance activities.