The use of lipid metabolic profiling to assess the biological impact of marine sewage pollution

Sydney rock oysters, Saccostrea commercialis, were deployed for a 3-month period at sewage-disturbed and control marine locations in the Hunter Region, New South Wales, Australia. After this period, the oysters were retrieved and the gills dissected and extracted for analysis of the saponified lipid components (including fatty acids and sterols), using gas chromatography-mass spectrometry (gc-ms). Multivariate analysis (discriminant function) of the gc-ms lipid profiles indicated that the lipid homeostasis in oysters from the sewage locations was significantly different compared with that observed in oysters from control locations (p < 0.0001). The primary factor discriminating between sewage and control locations was the level of beta-sitosterol, a plant sterol derived from domestic sewage and marine algae. The results indicate that gill lipid metabolism differentially alters in response to deployment of oysters into either sewage-contaminated or control locations. This method of analysis provides a sensitive measure for the biological impact of composite waste cocktails on strategically located marker organisms in affected environments.