Petty, T. J., J.L. Hansbarger, B.M Huntsman and P.M. Mazik. 2012. Differential movement by brook trout and brown trout along a stream size continuum in a central Appalachian watershed. Transactions of the American Fisheries Society. 141:4 Pages 1060-1073.
We used radio telemetry to quantify brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) movements in a large open canopy mainstem (Shavers Fork) and a small closed-canopy tributary of Shavers Fork (Rocky Run), in eastern West Virginia, USA. Our objectives were to quantify the overall rate of trout movement; assess variation in movement behaviors between seasons, years, trout species (brook vs. brown), and streams (Shavers Fork vs. Rocky Run); and relate movement behaviors to variation in stream flow, water temperature, and access to coldwater refugia. Water temperature, trout movements and microhabitat use were quantified separately in each of three seasons (summer 2000, fall 2000, and summer 2001). The study area experienced extremely high seasonal, yearly, and stream-to-stream variability in water temperature. Despite high summer ambient water temperatures, trout residing in the mainstem were never observed in water exceeding 19.5º C. Trout movements varied significantly seasonally and between Rocky Run and Shavers Fork. We observed no differences between species in the overall movement patterns of trout residing in the Shavers Fork mainstem. Mainstem inhabitants exhibited high overall movement rates in summer 2000 and 2001 (median movement rates ranged from 26 – 57 m/day) but low rates in fall 2000 (median movement rates < 1 m/day). Mainstem inhabitants also exhibited a strong tendency to move upstream over time in summer months (many individuals moved 1.5 – 6-km upstream over an 8-week period) but not in fall 2000. In contrast, tributary inhabitants exhibited consistently lower rates of movement, ranging from 0.1 m/day in fall 2000 to 2.1 m/day in summer 2000, with no up- or down-stream movement bias observed. Brook trout movement rates during summer months were correlated with both the maximum water temperature experienced by the fish and the initial distance of the fish from a known coldwater source. Finally, during extremely warm periods, mainstem trout used microhabitats closer to cover than tributary inhabitants or mainstem inhabitants during cooler periods. Our results provide some of the first data on brook trout movements in a large Appalachian river system, and these data indicate that brook trout inhabiting larger streams are capable of moving greater distances than previously recognized. These results underscore the importance of a watershed scale perspective on brook trout behaviors and population dynamics