Seasonal movement of brown trout in a southern Appalachian river

Radio telemetry was used to evaluate the seasonal movement, activity level, and home range size of adult brown trout Salmo trutta in the Chattooga Riv er watershed, one of the southernmost coldwater stream systems in the Unite d States. In all, 27 adult brown trout (262-452 mm total length) were succe ssfully monitored from 16 November 1995 to 15 December 1996. During the day , adult brown trout were consistently found in small, well-established home ranges of less than 270 m in stream length. However, 8 of a possible 18 st udy fish made spawning migrations during a 2-week period in November 1996. The daytime locations of individual fish were restricted to a single pool o r riffle-pool combination, and fish were routinely found in the same locati on over multiple sampling periods. Maximum upstream movement during spawnin g was 7.65 km, indicating that brown trout in the Chattooga River have the ability to move long distances. Spawning brown trout returned to their pres - pawning locations within a few days after spawning. Brown trout maintaine d larger home ranges in winter than in other seasons. When spawning-related movement was deleted from the analysis, brown trout moved more on a weekly basis in fall than in summer. Brown trout were more active in fall and win ter than in spring and summer. Apart from spawning migrations, displacement from established home ranges was not observed for any fish in the study. A lthough summer water temperatures reached and exceeded reported upper therm al-preference levels, brown trout did not move to thermal refuge areas in n earby tributaries during the stressful summer periods.