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-mo nth period at sewage-disturbed and control marine locations in the Hun ter 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), u sing gas chromatography-mass spectrometry (gc-ms). Multivariate analys is (discriminant function) of the gc-ms lipid profiles indicated that the lipid homeostasis in oysters from the sewage locations was signifi cantly different compared with that observed in oysters from control l ocations (p < 0.0001). The primary factor discriminating between sewag e and control locations was the level of beta-sitosterol, a plant ster ol derived from domestic sewage and marine algae. The results indicate that gill lipid metabolism differentially alters in response to deplo yment of oysters into either sewage-contaminated or control locations. This method of analysis provides a sensitive measure for the biologic al impact of composite waste cocktails on strategically located marker organisms in affected environments.