Movement patterns of endangered Roanoke logperch (Percina rex)

Abstract –  Using mark–recapture methods, we studied movements of endangered Roanoke logperch ( Percina rex Jordan & Evermann), a benthic darter, at 12 riffle–run sites over a 9-year-long period in the Roanoke River, Virginia, USA. Our primary objective was to characterise movements among transects within sites, but we opportunistically recorded two between-site movements as well. Our recapture rate was low (22 of 485 marked fish), but most recaptured fish exhibited movements between tagging and recapture, relocating either to another transect within a site (12 fish) or to another site altogether (two fish). Within sites, Roanoke logperch exhibited fidelity over time to the areas in which they were initially marked. These restricted areas were lengthier than transects (>15 m) but shorter than entire riffle–runs (<150 m). The two between-site movements were extensive (3.2 and 2.5 km), observed over a long mark–recapture interval (2 and 5 years, respectively), and may have represented migratory or dispersal movements. Their detection required an unusually extensive study design. Both small- and large-scale movements fulfil important ecological functions for Roanoke logperch, and greater study of such movements in this and other darter species is needed to inform conservation choices.