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.

A Long-Term Study of Ecological Impacts of River Channelization on the Population of an Endangered Fish: Lessons Learned for Assessment and Restoration

“…Third, George and Mayden's [74] genetic study indicated that the range fragmentation of P. rex was anthropogenic and recent in nature and that the species probably dispersed more widely in the past. These findings about the surprising mobility of P. rex have been corroborated by additional, more recent genetic and movement studies [57,65]. The 1990 BO and monitoring plan implicitly assumed that P. rex population dynamics were regulated at the site or reach scale, and did not anticipate watershed-scale metapopulation dynamics.…”

“…We monitored P. rex and their habitat primarily to estimate incidental take and assess population-level impacts, even though basic knowledge about population dynamics of the species was initially sparse and uncertainty about how observed take related to these dynamics was high. Even so, our long-term (19 years) monitoring enabled us to learn valuable lessons that advanced our knowledge of P. rex ecology and made management for the species more cost-effective [56][57][58].…”

“…For example, we greatly expanded our knowledge of logperch movement [56,57,65,81], population viability [64], and juvenile habitat use [58]; we continue to study larval ecology and multi-scale habitat associations of P. rex [82]. We have developed and refined methodological knowledge germane to addressing conservation problems, including fish-marking techniques [57], microsatellite genetic markers [83], and estimates of P. rex detectability during electrofishing surveys. Over the years of the RRFRP we developed and compared methods for estimating P. rex abundance based on electrofishing versus snorkeling [84] and for evaluating habitat use in summer versus winter and by adults versus juveniles.…”

Fish movement in an Atlantic Forest stream

“…Schlosser, 1991). Movement frequency seems to be higher than expected (Gowan et al, 1994;Smithson, Johnston, 1999;Crook, 2004;Roberts et al, 2008;Breen et al, 2009), and stream fish populations are not completely sedentary. There are also some intra-population behaviour differences in which some individuals are sedentary, some are mobile, and others alternate between both behaviours (Knaepkens et al, 2005).…”

“…Rodríguez, 2002;Petty, Grossman, 2004). Nonetheless, it also received several criticisms (Riley et al, 1992;Young, 1994;Gowan, Fausch, 1996;Roberts et al, 2008;Breen et al, 2009). Gowan et al (1994) found, for example, that streamdwelling fish can move long distances when conditions in their present foraging location become sub-optimal relative to conditions at other locations in the same reach.…”