Radio telemetry was used to monitor the diel movement of 22 brown trout Salmo trutta (268–446 mm in total length, TL) in the Chattooga River watershed. Forty‐seven diel tracks, locating individuals once per hour for 24 consecutive hours, were collected for four consecutive seasons. High variability in movement both within and among individual brown trout resulted in similar seasonal means in total distance moved, diel range, and displacement. The majority of fish moved a total distance of less than 80 m within a diel range of less than 80 m and had a displacement of less than 10 m. Brown trout were more likely to occur in pool habitat independent of season or period of the day. Hourly movement patterns differed among seasons. During the winter and fall, trout moved only around sunrise; during the spring, they moved around sunrise, sunset, and intermittently throughout the night. Large brown trout (>375 mm, TL) were found to move greater total distances and establish wider diel ranges than small brown trout. Overall, most brown trout exhibited restricted diel movement within a single riffle–pool or run–pool sequence.
The robust redhorse Moxostoma robustum is a large riverine catostomid whose distribution is restricted to three Atlantic Slope drainages. Once presumed extinct, this species was rediscovered in 1991. Despite being the focus of conservation and recovery efforts, the robust redhorse's movements and habitat use are virtually unknown. We surgically implanted pulse-coded radio transmitters into 17 wild adults (460-690 mm total length) below the downstream-most dam on the Savannah River and into 2 fish above this dam. Individuals were located every 2 weeks from June 2002 to September 2003 and monthly thereafter to May 2005. Additionally, we located 5-10 individuals every 2 h over a 48-h period during each season. Study fish moved at least 24.7 6 8.4 river kilometers (rkm; mean 6 SE) per season. This movement was generally downstream except during spring. Some individuals moved downstream by as much as 195 rkm from their release sites. Seasonal migrations were correlated to seasonal changes in water temperature. Robust redhorses initiated spring upstream migrations when water temperature reached approximately 128C. Our diel tracking suggests that robust redhorses occupy small reaches of river (;1.0 rkm) and are mainly active diurnally. Robust redhorses were consistently found in association with woody debris and gravel streambed sediments along the outer edge of river bends. Fish exhibited a high degree of fidelity to both overwintering and spawning areas. Our observations of long-distance seasonal migrations suggest that successful robust redhorse conservation efforts may require an ecosystem management approach.
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