In Situ Variations in Oyster Mutagenicity and Tissue Concentrations of Polycyclic Aromatic Hydrocarbons*

Abstract

Variations in oyster mutagenicity were monitored in a series of in situ relocation experiments and compared with tissue concentrations of polycyclic aromatic hydrocarbons (PAHs). Oysters (Crassostrea virginica) were relocated among three rivers in the southern Chesapeake Bay and sampled over a 2-week exposure period. Extracts of oyster tissues were assayed for mutagenic activity by the Salmonella typhimurium microsomal test and analyzed for selected PAHs by gas chromatography. Oysters relocated to the polluted Elizabeth River (Norfolk, VA) from a pristine site (Ware River, VA) accumulated mutagenic activity and PAHs within 3 d following relocation. Mutagenicity increased over a 14-d period while tissue levels of most PAHs stabilized or declined after 3 d. Extracts of native oysters from the Elizabeth River exhibited comparable levels of mutagenic activity as 14-d relocated oysters. In elimination experiments, PAH levels and mutagenic activity of Elizabeth River oysters decreased following relocation to the Ware River and were not detected after 14 d. Regression analyses did not detect a significant association between slopes of mutagenicity dose-responses and tissue levels of PAHs. Marginal associations with numbers of Salmonella revertants per plate were detected in comparisons with sums of PAH tissue levels, and with tissue levels of benzofluoranthene.

Fluoranthene induced changes in photosynthetic pigments, biochemical compounds and enzymatic activities in two microalgal species: Chlorella vulgaris Beijerinck and Desmodesmus subspicatus Chodat

“…PAHs are acting as carcinogens, mutagens, and endocrine disruptors to a variety of aquatic organisms, (Pittinger et al, 1987;Hellou et al, 2006). Identification of the key organisms that play a role in pollutant degradation processes is relevant to the development of optimal in situ bioremediation strategies.…”