Bioaccumulation of butyltins in Dreissena polymorpha at a confined placement facility in Buffalo, New York

This study involves a site characterization followed by biomonitoring with the zebra mussel, Dreissena polymorpha, at the Times Beach confined placeme nt facility (CPF), located in Buffalo, NY. The contaminant of interest was tributyltin (TBT) and the degradation products dibutyltin (DBT) and monobut yltin (MBT). At study initiation (Day 0) TBT levels in the baseline mussels were 5.86+/-0.43 ng Sn/g, DBT levels were 2.25+/-0.37 ng Sn/g. No MBT was detected in the Day 0 baseline samples. Caged reference mussels placed back in the Black Rock Channel Lock and retrieved on Days 19 and 34 had TBT, DB T, and MBT levels which did not differ significantly from the Day 0 baselin e levels. Mussels placed at the Times Beach CPF had TBT concentrations that were significantly lower at both Days 19 (3.65+/-0.90 ng Sn/g) and 34 (3.5 0+/-1.03 ng Sn/g) than the Day 0 baseline analysis (5.86+/-0.43 ng Sn/g). T he results of this study indicate that butyltins were detected at the CPF s ite in the sediment (7.33+/-5.70 ng Sn/g) but not the water column (not det ected at 0.01 mug/l). In this study the zebra mussel was able to depurate T BT even in the presence of contaminated sediment. TBT may be bioaccumulated from the sediments. However, the initial levels in the mussels were so hig h, levels actually dropped as sediment-tissue equilibria levels were reache d by the mussels. (C) 2000 Elsevier Science Ltd. All rights reserved.