ABSTRACT
The unusually narrow margin between nutritional requirement and toxicity, complex biogeochemical cycling, and heterogeneous distribution all contribute to the difficult problem of selenium (Se) contamination. This is well illustrated by the wildlife deformities that occurred in California’s Kesterson Reservoir in the early 1980s. The toxic symptoms observed have since been attributed to Se bioaccumulation and biotransformation through the food chain (Skorupa and Ohlendorf, 1991; Maier and Knight, 1994). However, Se biotransformation through the aquatic food web is largely unknown. This ecotoxicological effect is becoming a major concern for agricultural operations in seleniferous soils and for industrial discharges throughout the United States (Skorupa and Ohlendorf, 1991; Fairbrother et al., 1996; Reash et al., 1996). Long-term solutions to the selenium problem need to be explored to make these agricultural and industrial activities sustainable.
