Trace elements in 15 walleye (Sander vitreus) tissues taken from the Pueblo Reservoir in Colorado corresponded to many metals of worldwide concern and were the same as those released into the Arkansas River from decades of mining at Leadville, Colorado. Therefore, analyses of walleye stomach contents, gizzard shad (Dorosoma cepedianum; a dietary prey item for walleye), and tissues of walleye were compared for an increase in, or a deficiency of, Cu, Zn, As, Cd, and Pb. Tissues were compared as couplets but also evaluated with tissues clustered into 6 functional groups. The trace elements were found to be tissue distinctive and functional-group specific. An interesting finding was that muscle, liver, gill, or whole bodies of fish - often indicators of trace elements - may not be as illustrative as adipose, skin, heart, bone, or stomach contents of the walleye. Results showed no significant differences in amounts of Pb among tissues within any of the 6 functional groups. We suggest that only 6 of 15 tissues might be necessary to indicate the uptake or lack of elements: heart, adipose, skin, bone, liver, and muscle, the latter of value for human consumption. Elements in gizzard shad, walleye stomach contents, livers, and muscle reflected historical element-rich colloidal sediments in the Arkansas River above the Pueblo Reservoir inlet. Despite the presence of trace elements in walleye tissues, this study suggests that a robust fishery of walleye in the Pueblo Reservoir exists and is likely to increase in the future.
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