PARENT SESSION
WP1 - Bioavailability
Chair: Ranville, Jim1, 1 Colorado School of Mines, Golden, CO
2:10 PM to 5:30 PM - Wednesday, 20 November 2002
Room Ballroom G-I
(576) PAH exposure pathways and accumulation in Leptocheirus plumulosus exposed to contaminated sediments from the Chesapeake Bay .
Klosterhaus, Susan*,1, Merten, Amy1, Miller, Thomas1, Baker, Joel1, 1 University of Maryland Chesapeake Biological Laboratory, Solomons, MD, USA
ABSTRACT- As part of a larger project to characterize population-level effects of contaminated sediments on living resources in the Chesapeake Bay, Leptocheirus plumulosus were exposed to sediments collected from Baltimore Harbor (BH) and the Elizabeth River (ER) for 90 days in laboratory flow-through tanks. Amphipods were fed perdeuterated PAH-spiked algae for the first weeks and uncontaminated algae for the remainder of the experiment. PAHs in Leptocheirus, sediments, and the dissolved and suspended phases were quantified throughout the experiment to determine the relative magnitudes of each exposure pathway. PAH concentrations in ER sediments were nearly 50 times higher than those in BH sediments, and the resulting dissolved PAHs were elevated in the ER exposures compared to the BH tanks. PAH concentrations on suspended particles in the tanks were much lower than supported by sediment resuspension, and may have been the result of a high flushing rate and/or other particle sources in the tanks. By day 90, concentrations of many high molecular weight PAHs in Leptocheirus reached steady-state and those exposed to ER sediments contained up to 15 times more PAH than did those exposed to BH sediments, which is less than the 50x enrichment predicted from the sediment PAH concentrations. In general, Leptocheirus PAH concentrations in both the BH and ER sediments were lower than their surrounding sediment concentrations. In comparison to BH field-collected amphipods, laboratory-exposed amphipods accumulated higher concentrations of the low to mid molecular weight PAHs and similar concentrations of the high molecular weight PAHs. PAH profiles in the amphipods mirror those in the sediments for all treatments, with Leptocheirus accumulating a range of PAHs in the BH exposures and very high concentrations of the mid to high molecular weight PAHs in the ER exposures. Differences in accumulation patterns most likely result from differences in PAH source.
Key words: PAH, Leptocheirus, bioaccumulation, Chesapeake Bay