SREL Reprint #3451

Evaluation of diffusive gradients in thin films for prediction of copper bioaccumulation by yellow lampmussel (Lampsilis cariosa) and fathead minnow (Pimephales promelas)

Rebecca R. Philipps1, Xiaoyu Xu1, Gary L. Mills1, and Robert B. Bringolf2

1Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, USA
2Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, USA

Abstract: Using a coupled method of diffusive gradients in thin films (DGT) exposure with aquatic organism bioassays, we assessed the use of DGT as a tool for estimating copper (Cu) bioavailability in contaminated waters. The DGT-accumulated Cu fraction could possibly be used as a surrogate for other assessments of metal bioavailability. The Cu concentrations in fathead minnow (Pimephales promelas) and yellow lampmussel (Lampsilis cariosa) soft tissue were compared with DGT-accumulated Cu after 2, 4, and 6 d of exposure to a Cu concentration series in static, water-only assays. The DGT-accumulated Cu was found to include free Cu ions, labile inorganic Cu complexes, and labile dissolved organic matter Cu complexes, compared with Cu speciation output from the biotic ligand model. Regressions of Cu concentrations between DGT and fathead minnow at 4 and 6 d of exposure demonstrated linear relationships. The Cu bioaccumulated in yellow lampmussel was overpredicted by DGT at Cu concentrations greater than 10µgL-1, which may be caused by internal regulation of Cu. The speciation component of the biotic ligand model predicted relationships between inorganic Cu and animal-accumulated Cu that were similar to predicted relationships between DGT-indicated Cu and animal-accumulated Cu at all deployment durations.

Keywords: Copper; Bioaccumulation; Bioavailability; Diffusive gradients in thin-films; Biotic ligand model; Metal speciation

SREL Reprint #3451

Philipps, R. R., X. Xu, G. L. Mills, and R. B. Bringolf. 2017. Evaluation of diffusive gradients in thin films for prediction of copper bioaccumulation by yellow lampmussel (Lampsilis cariosa) and fathead minnow (Pimephales promelas). Environmental Toxicology and Chemistry 37(6): 1535-1544.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).