MIGRATORY DISTRIBUTION OF FLUVIAL ADULT BULL TROUT IN RELATION TO LAND AND WATER USE IN WATERSHEDS WITHIN THE MID-COLUMBIA AND SNAKE RIVER BASINS. Starcevich, S., J., Howell, P., J., & Jacobs, S., E. In Wild Trout X Symposium-Conserving Wild Trout, volume 3, pages 258-266, 2010.
MIGRATORY DISTRIBUTION OF FLUVIAL ADULT BULL TROUT IN RELATION TO LAND AND WATER USE IN WATERSHEDS WITHIN THE MID-COLUMBIA AND SNAKE RIVER BASINS [pdf]Paper  MIGRATORY DISTRIBUTION OF FLUVIAL ADULT BULL TROUT IN RELATION TO LAND AND WATER USE IN WATERSHEDS WITHIN THE MID-COLUMBIA AND SNAKE RIVER BASINS [link]Website  abstract   bibtex   2 downloads  
Radio telemetry was used to investigate migratory patterns of 198 fluvial adult Salvelinus confluentus (mean, 449 mm FL) in relation to land and water use characteristics in the Imnaha, Grande Ronde, Walla Walla, Umatilla, and John Day river basins. Median migration distances of radio-tagged fluvial bull trout from the Imnaha (89 km) and Wenaha (56 km) and Lostine (41 km) rivers were relatively long. These study areas were characterized by low levels of water consumption, private landownership, and population density. Median migration distances were significantly shorter in the John Day (8 km) and Umatilla (22 km) rivers and Mill Creek (20 km), which were characterized by greater water and land use and no known barriers to movement. Bull trout from the Lostine and Wenaha rivers also returned to habitats in winter that were more extensive (73 and 86 km, respectively), and the spawning and wintering areas were spatially separated. In contrast, winter locations of bull trout in the John Day, Walla Walla, and Umatilla river were distributed over a relatively short mainstem reach (<25 km) adjacent to or overlapping the spawning distribution. These results suggest adult fluvial migration may be restricted in basins with substantial water and land use. Additional research on bull trout ecology in larger rivers and the effects of anthropogenic habitat degradation on the spatiotemporal distribution of critical resources will lead to a better understanding of how migrations patterns are established and the factors that limit distribution.

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