Microhabitat Suitability of Common and Imperiled Atlantic Slope Freshwater Mussels

The southeastern United States supports the highest global diversity of freshwater mussels that includes a number of imperiled species.  We selected 20 sites that span a broad range of environmental conditions within the Tar River Basin, North Carolina, for intensive study of mussel habitat requirements.  Each site was surveyed for common (e.g., Elliptio complanata) and imperiled mussels (the federally endangered Tar spinymussel (Elliptio steinstansana) and dwarf wedgemussel (Alasmidonta heterodon)).  Microhabitat parameters were measured at base flow conditions at all sites.  Microhabitat use parameters including depth, velocity, substrate, cover, and sediment compaction were measured and combined with habitat availability data to describe microhabitat suitability for freshwater mussels in the basin.  These results are a component of a broader project that will incorporate habitat suitability functions into multistate mussel occupancy models.  Occupancy models will then form the biological basis for watershed and instream biological response models that will simulate scenarios related to climate and land use change to guide conservation efforts.