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Show The U. S. Fish and Wildlife Service ( USFWS 1985) has summarized information on selenium in fish for Arizona. Residue data are from samples of nine species of fish collected between 1972 and 1980 at 12 stations across the state, including one at Lake Powell. In the Arizona data base, elevated concentrations (> 2,000 ppb) of selenium in fish appear only in the Colorado River stations. Selenium in concentrations above 2000 ppb whole body weight can cause reproductive problems in fish; at levels of 5000 ppb or more, reproductive problems are a certainty ( USFWS 1985). Recommended limits for selenium have not been established for fresh- water fish consumed by humans. In comparison, the recommended concentration limit for selenium in ocean commercial fisheries is 2 mg/ kg of wet weight ( Ron Eisler, U. S. Fish and Wildlife Service, personal communication, 1986). Other trace metals in Lake Powell fish were investigated in a report by Bussey et al. ( 1976). Ten tissue samples from each of four species of fish ( largemouth bass, black crappie, walleye, and rainbow trout) were analyzed for the presence of these ten heavy metals: iron, calcium, magnesium, copper, chromium, cadmium, zinc, arsenic, selenium, and lead. The study indicates that, with the possible exception of selenium, none of the other metals analyzed appear in concentrations high enough to pose a known health hazard. Reflecting the high levels known to exist in the plankton and sediments of the lake, high selenium concentrations were observed in all fish tissues sampled. Selenium levels in fish flesh ranged from 6.4 mg/ kg to 16.8 mg/ kg, and in bass these levels appeared to be dependent upon size. Relatively high levels of lead were observed ( compared with other stations), which possibly can be attributed to recreational activities such as the use of outboard motors. The Utah Department of Natural Resources, Division of Wildlife Resources ( UDWR), annually publishes reports of numerous studies on measurements of fish harvest, food base, and population trends. The UDWR manages fishing in Lake Powell through licenses and limits on fish catch ( UDNR 1983). The U. S. Environmental Protection Agency ( EPA) has recently been funding nationwide monitoring for the Priority Pollutant List, which includes 129 metals and pesticides in water, sediments, and fish of major drainages. At Lake Powell, water, sediment, and fish samples were collected and analyzed by the U. S. Fish and Wildlife Service in May, 1985. Preliminary results of this study, available from the EPA's STORET data base, indicate that high concentrations of selenium are being found in fish tissue. Table 3 presents the results of two years of sampling of heavy metals in fish flesh by the USFWS National Contaminant Biomonitoring Program. 47 |