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<br />the three tributary sites seem to be comparable to those samples collected <br />from the Uncompahgre River. Selenium concentrations were less than 2.4 ~g/g <br />dry weight (table 22) in the five aquatic plant samples collected from the <br />three tributaries. <br /> <br />The effects of irrigation drainage on fish in the Gunnison and <br />Uncompahgre Rivers and the three tributaries are not known. Selenium and <br />other trace-element concentrations may not be sufficiently large to cause <br />direct mortality, although selenium concentrations may be sufficient to affect <br />reproduction. The transport of selenium from the Gunnison River basin into <br />the Colorado River may be of concern for endangered fish in the Colorado <br />River. <br /> <br />Cadmium <br /> <br />Four cadmium concentrations in fish collected from the Uncompahgre River <br />at Colona (site 4 in table 21) are slightly larger than the NCBP's 85th per- <br />centile of 0.24 ~g/g dry weight and are slightly larger than concentrations of <br />cadmium in fish collected from a relatively uncontaminated part of Palestine <br />Lake in Indiana (Murphy and others, 1978). Murphy and others (1978) stated <br />that average cadmium concentrations for fish from relatively uncontaminated <br />aquatic ecosystems ranged from 0.08 to 0.38 ~g/g dry weight. In addition, <br />several other sources (Lovett and others, 1972; Hammons and others, 1978; <br />Jenkins, 1980; May and McKinney, 1981) listed background concentrations of <br />cadmium in fish that exceeded the cadmium concentrations in fish collected at <br />site 4. <br /> <br />Cadmium was detected in the livers of four adult killdeer, two each from <br />Sweitzer Lake (site 7) and the Escalante State Wildlife Area (site 10), and <br />one adult mallard from the wildlife area (tables 15, 20, and 23). These con- <br />centrations are greater than cadmium concentrations in livers of one-year-old <br />mallard ducks that were fed 2 ~g/g cadmium for 30 to 60 days, but were less <br />than the cadmium concentrations in livers of mallards fed the same diet for <br />90 days (White and Finley, 1978). Although no adverse affects were observed <br />in bird groups fed 2 and 20 ~g/g of cadmium, birds in both study groups accu- <br />mulated cadmium in the liver at concentrations similar to the concentrations <br />in their diets and in the kidney at concentrations about 2.5 times the concen- <br />trations in their diets (White and Finley, 1978). Cadmium concentrations in <br />invertebrate and aquatic plant samples collected at site 4 were within the <br />ranges listed by Jenkins (1980) and Hammons and others (1978) for cadmium <br />concentrations in aquatic organisms. <br /> <br />Copper <br /> <br />Copper was detected in 17 of 55 whole-body fish samples (tables 20-23), <br />including all the samples collected at Uncompahgre River at Colona (site 4 <br />in table 21). The range of concentrations is summarized in table 13. Thir- <br />teen samples had copper concentrations that exceeded the NCBP 85th percentile <br />for copper of 3.6 ~g/g dry weight (Lowe and others, 1985). Those samples were <br />collected from the Gunnison River at Escalante State Wildlife Area (site 10), <br />at both sampling sites on the Uncompahgre River (sites 4 and 9), from Happy <br />Canyon, Spring, and Dry Creeks (sites 12, 13, and 14), and from Sweitzer Lake <br /> <br />60 <br />