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002360 There were no significant differences (significance level of 0.05) in selenium concentrations of bird livers, eggs, and whole-body samples between Sweitzer Lake and the Gunnison River at Escalante State Wildlife Area (figs. 18 and 19; tables 15, 20, and 23). Selenium concentrations in whole- body bird samples collected at the wildlife area (site 10) ranged from 3.3 ~g/g dry weight in an immature Canada goose to 19.6 ~g/g dry weight in an immature mallard (table 20). Selenium concentrations in bird liver samples ranged from 6.5 ~g/g dry weight in an immature Canada goose to 54.2 ~g/g dry weight in a killdeer. Selenium concentrations in eggs ranged from 2.8 ~g/g dry weight in a Canada goose egg to 8.6 ~g/g dry weight in a red-winged blackbird egg (table 20). Because of the close proximity of locations, birds collected from the Escalante State Wildlife Area also may have foraged at Sweitzer Lake where they may have accumulated selenium. Although selenium concentrations in fish, invertebrates, and aquatic plants collected at the wildlife area were less than the selenium concentrations at Sweitzer Lake (fig. 18), the concentrations in water and avian food items (including fish) may be large enough to cause problems due to food-chain biomagnification. Selenium concentrations in birds from the wildlife area indicate considerable exposure to selenium, and impairment of reproduction could have occurred because concentrations were similar to those found by Ohlendorf and others, 1986; Heinz and others, 1987; Heinz and others, 1989. No embryo deformities were detected in samples collected at the Escalante State Wildlife Area, but eggs were collected before they were one-half of the way through incubation. External morphology of young killdeer, blackbird, and waterfowl samples appeared normal. Selenium concentrations in fish samples collected from the Uncompahgre River [at Colona (site 4) and at Delta (site 9)] were significantly (signifi- cance level of 0.05) less than selenium concentrations in fish samples from the Gunnison River at sites 3 and 10 (tables 13 and 14, fig. 16). Selenium concentrations in fish samples collected from the Uncompahgre River ranged from less than 1.5 ~g/g dry weight in a flannelmouth sucker to 6 ~g/g dry weight, also in a flannelmouth sucker (table 21). Selenium concentrations in eight fish samples from the Uncompahgre River exceeded the 1980-81 NCBP 85th-percentile concentration of 2.8 ~g/g dry weight. There was no signifi- cant difference (significance level of 0.05) between selenium concentrations in fish samples collected at Colona (site 4) and fish samples collected at Delta (site 9). Selenium concentrations in fish collected at Colona and Delta (table 21) were not substantially greater than the selenium concentrations in fish samples collected upstream from the Uncompahgre Project area at Ridgway Reservoir and from the Uncompahgre River downstream from Ridgway Reservoir (table 7). Selenium concentrations in fish samples collected from Happy Canyon Creek (site 12), Spring Creek (site 13), and Dry Creek (site 14) were not signifi- cantly different (significance level of 0.05) than selenium concentrations in fish samples collected from the Uncompahgre River (fig. 16; tables 13, 21, and 22). Selenium concentrations in fish samples collected at the three tributary sites ranged from 1.3 ~g/g dry weight in a composite sucker sample to 10.5 ~g/g dry weight in a carp sample collected from Dry Creek (table 22). Eight fish samples from the tributary streams had selenium concentrations exceeding the 1980-81 NCBP 85th-percentile concentration of 2.8 ~g/g dry weight for selenium. Selenium concentrations in invertebrate and aquatic plant samples collected at 59