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I During 1987, two composite rainbow trout samples were taken from Hotchkiss National Fish Hatchery to be analyzed for trace element contaminants. Comparisons were made between these values (Table 1), and contaminant levels found in four Colorado squawfish (Table 2) which were captured from the White River in July-August 1986, and held at Hotchkiss hatchery for approximately 8-9 months until they died in April 1987. Arsenic levels were elevated in Hotchkiss hatchery trout samples (Table 1) at 0.99 and 1.2 ug/g dry weight, when compared to the 1980-81 National Contaminants Biomonitoring Program (NCBP) 85th-percentile concentration (Lowe et al 1985) of 0.88 ug/g dry weight. Colorado squawfish #1 and #2 also had high arsenic values of 0.96 and 0.84 ug/g dry weight, respectively. However, Colorado squawfish #3 and #4 had arsenic values equal to or below the NCBP mean of 0.46 and 0.55 ug/g dry weight, respectively. Colorado squawfish may have accumulated arsenic from either food or water at Hotchkiss hatchery, though they could also have accumulated arsenic from the White River. Arsenic levels occurring in the two hatchery rainbow trout samples were below the suggested value of <0.5 mg arsenic per kg of total dry weight consumed by people (Eisler 1988), when considering an average fish weight of 440 g and 75% moisture (0.132 mg As/fish dry wt). Also, these arsenic values were from whole fish samples, and because the liver accumulates the highest arsenic concentration when compared to other tissues (Oladmeji et al 1984), actual levels of arsenic consumed by people would most likely be less than those mentioned above. Moore and Ramamoorthy (1984) note that toxic inorganic arsenicals are rapidly transformed to organic arsenic in fish, and these organic forms are readily excreted by humans and are of low toxicity. They suggest that the 0.5 mg/kg standard may not be consistent with possible hazards posed to humans.