Chromium in rainbow trout from an exposed dunite formation, twin sisters mountain, washington

Abstract

Twin Sisters Mountain, Washington, is dominated by a dunite rock formation containing the mineral chromite (iron magnesium chromium oxide: (Fe, Mg)OCr2O3). We sampled rainbow trout and collected water samples from Howard Creek, a Twin Sister watershed. From 0.5 to 3.7 mg Cr/kg fresh weight was found. However, concentration of Cr was not related to fish size. Since Cr was not detected in the water, the route of uptake by fish is likely through ingestion. Since the range of concentrations of Cr in these fish overlaps with those that have been found to adversely affect health, these fish may have adapted to tolerate Cr. © 2010, Copyright Taylor & Francis Group, LLC.