Population Structure and Genetic Characteristics of Summer Steelhead ('Oncorhynchus mykiss') in the Deschutes River Sub-basin, Oregon. Project Progress Report FY 2007

摘要

Summer steelhead trout (anadromous form of Oncorhynchus mykiss) in the Deschutes River subbasin, are part of the Mid-Columbia Steelhead Evolutionarily Significant Unit (ESU) that has been listed as threatened by NOAA-Fisheries since 1999. In order to evaluate recovery needs and implement a recovery plan for steelhead in the Deschutes River, the Interior Columbia River Technical Recovery Team (2003) attempted to characterize population structure and identify discrete populations throughout the subbasin. The Deschutes River Basin represents a region of substantial diversity among O. mykiss spp (Kostow 1995), likely indicative of multiple colonization events (Currens et al. 1990), and the influence of geologic and hydrologic barriers (Currens et al. 1990; Zimmerman and Ratliff 2003, Stuart et al. 2007). The current distribution and genetic origins of populations throughout the Deschutes River Basin have not been clearly delineated. Similarly the relationship between life history types (i.e. resident and anadromous) through much of the region is poorly understood.