Theses and Dissertations Collection

Rainbow Trout Oncorhynchus mykiss are of conservation and management interest because of their genetic diversity, facultatively anadromous life histories, and importance to recreational fisheries. Summer steelhead, the anadromous form of Rainbow Trout, have been introduced to novel basins to increase recreational fishing opportunities. However, these introductions can pose threats to endemic populations of steelhead; thus, these programs must be evaluated to determine if releases lead to potential impacts on endemic populations. Steelhead also display greater life history diversity compared to most anadromous salmonids, and understanding the mechanisms that produce life history variability is important. This thesis sought to characterize the movement and fate of adult non-local hatchery-produced summer steelhead released back to tributaries of the Willamette River, Oregon. I also examined the importance of freshwater and ocean growth in producing life history variability in steelhead. Jointly, the objectives contribute to refining the management and conservation of steelhead.