Demography of freshwater mussels within the lower Flint River Basin, southwest Georgia

Abstract

Environmental and spatial variation can potentially influence mussel populations through acute and chronic mechanisms. The objectives of this study were to identify and quantify the chronic factors affecting freshwater mussel growth. Live mussels were collected within the lower Flint River Basin, sacrificed, and their shells were thin-sectioned. Thin sections revealed the production of internal annuli, which were used to determine individual ages and estimate annual growth. I evaluated the relation between annual growth and presumed variables responsible for altering growth using mixed linear models. Growth was indicated to vary in relation to seasonal streamflow, species, age, tagging, channel confinement, and physiographic province. The effect of tagging should be accounted for in subsequent mark-recapture studies, and species- and site-specific characteristics should be considered when implementing management decisions to prevent future harm to freshwater mussel populations.