Abstract
This study evaluates the suitability of using Hyalella azteca as a predictor of the risk that tributyltin (TBT) poses to freshwater invertebrates by comparing the toxicity and bioaccumulation of TBT in H. azteca to five species: Hexagenia limbata, Physella gyrina, Tubifex tubifex, Chironomus riparius and Daphnia magna. Young from each species were added to aquaria containing sediment spiked with TBT concentrations of 0, 28.6, 258 and 1900 ng Sn/g dry weight. Chironomus riparius data could not be quantified reliably due to poor control survival. Bioaccumulation of TBT in the five remaining species was similar at sediment concentrations of 258 ng Sn/g, and the bioaccumulation relationships of P. gyrina and H. azteca were virtually identical. No toxicity was evident in any test species at body concentrations of 1100 to 1800 ng Sn/g. Body concentrations of 4000 to 6000 ng Sn/g were associated with significant (p < 0.05) mortality in H. limbata, P. gyrina, T. tubifex and D. magna, but not in H. azteca. However, bioaccumulation of TBT in H. azteca was comparable and can be used in predicting the effects of environmental TBT concentrations on these four species of freshwater invertebrates.
