Native Fish Populations in the Middle Columbia River Jennifer Taylor Abstract: Subregion 1707 is comprised of the section of the Columbia River from its confluence with the Snake River to Bonneville Dam as well as the John Day River and Deschutes River Basins. Its geology was shaped by the formation of the Columbia River Flood Basalts as well as the regional uplift of the Cascade Range and the floods during the Pleistocene which left fluvial deposits. The region was settled as a largely an agricultural area with incentives to develop and cultivate the land under the Homestead Act. The USGS water data from the area reflects the predominance of agricultural use in that 97 percent of the consumptive water use is devoted to agriculture. The main-stem of the Columbia River has four dams (McNary, John Day, The Dalles and Bonneville) which act as an impediment to native fish passage. Awareness was heightened for the fish when several species of Snake River salmon were listed as endangered in the early 1970's. Native returning adult fish populations historically ranged between 10 and 16 million fish and the low was hit in 1995 at 750,000 fish. Options for fish recovery include hatcheries, drawdowns, flow augmentation, increasing spill, transportation of smolts, breaching dams and improving land-use practices. As of yet, no single plan has been successfully implemented to recover native fish populations. However, collaborative efforts are being made amongst the numerous factions and an integrative approach would prove to be beneficial to all involved parties. Key References: Dauble, D. D. and D. G. Watson. 1997. Status of the Fall Chinook Salmon Population in the Mid-Columbia River, 1942-1992. North American Journal of Fisheries Management 17 (1997): 283-300. Giorgi, A. E., T. W. Hillman, J. R. Stevenson, S. G. Hays, and C. M. Peven. 1997. Factors that influence the downstream migration rates of juvenile salmon and steelhead through the hydroelectric system in the Mid-Columbia river basin. North American Journal of Fisheries Management 17 (1997): 268-282. USDA and Forest Service. 1996. Status of the Interior Columbia River Basin: Summary of Scientific Findings. 1996. Stelle, William Jr. (1998) Overcoming the seven myths of the Columbia River salmon recovery. Environmental Law. 28 (Fall): 493-503.   Return to Water Resources Papers page.