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1.1 Background This project was justified based on a belief that entrenched, existing programs are causing institutional resistance to consolidating and integrating historical and new research into a comprehensive description of the linkages among selenium, water development, and wildlife. Selenium toxicity is presumed to be the primary cause of avian teratogenesis at the Kesterson National Wildlife Refuge and some other locations in the western United States. Selenium toxicity also has been implicated in the collapse of several populations of endangered fish (Bureau of Reclamation 1998). The premise for ascribing the poisoning to selenium has its origin, in part, on the belief that a livestock disease called blind staggers was caused by selenium (Beath et al. 1953). High concentrations of selenium in animal tissue and the abundance of seleniferous plants were related to blind staggers. Consequently, selenium tissue concentrations have been used to guide recent investigations and programs related to the recovery of endangered fish such as the Colorado River squawfish (now pikeminnow) and. the razorback sucker. The role of selenium, however, is disputed as shown by recent publications advocating a much higher standard for protection of aquatic life in western streams (Canton 1999). Research published in the veterinary literature suggests that blind staggers in cattle is not caused by selenium but by sulfate and other factors associated with high salt/alkaline soils (O'Toole and Raisbeck 1995). This research also shows that selenium causes sterility but is not teratogenic to livestock. Other work shows that pronghorn, indigenous to high selenium locales, tolerate relatively high levels of selenium in their blood, and that mallards confined to a high selenium diet would starve rather than eat the food (Raisbeck et al. 1996). Taken together, these data suggest that the original premise implicating selenium could be overemphasized. Moreover, the data suggest that indigenous, endangered fish in the intermountain West also could be relatively tolerant of selenium. Indeed, the fish recovery programs are guided to some extent by selenium analyses of tissue plugs, a practice that the veterinary research refutes in mammals (O'Toole and Raisbeck 1995). Researchers have also been monitoring and reporting changes within the Colorado River system (Van Steeter and Pitlick 1998). Recent published reports show that the Colorado River, in the Grand Valley, has lost approximately 30% of its average flow in the past 40 years. The average width of the river has decreased by approximately 60 ft in the same time period. Aerial photos show that the complexity of the habitat associated with the river also has declined at a significant rate. Furthermore, the preceding documented changes do not address the considerable alterations to the flow regime (suppressing spring runoff, prolonging summer/fall runoff, decreasing sediment load, decreasing summer temperature, increasing winter temperature) caused by water diversions and. dams. 1.2 Project Scope This project was supported from the Seed Money Fund of the Laboratory Directed Research and Development Program at Oak Ridge National Laboratory. The project funding of approximately $14,000 resulted in a limited scope that included a comprehensive literature search, in-depth interviews with researchers in the field (Table 1), and a field survey of habitat in the Grand Valley. Those contacted are listed in Table 1.