Polychlorinated dibenzo-p-dioxins and dibenzofurans in great barrier reef (Australia) dugongs (Dugong dugon).

Fat tissue samples from dugong (Dugong dugon) carcasses stranded at three s ites along the Great Barrier Reef were analysed for polychlorinated dibenzo -p-dioxins (PCDDs) and dibenzofurans (PCDFs). Relatively high levels of PCD Ds were determined in all three dugongs. In particular OCDD, the PCDD/F con gener that is usually considered the least bioavailable of all 2,3,7,8 subs tituted congeners, was found at levels higher than reported for other marin e mammals. Tissue accumulation of PCDDs by dugongs may be a consequence of sediment and/or seagrass ingestion during feeding, microbial biotransformat ion of PCDD precursors in the animal's hindgut or, alternatively, the posse ssion of a selective degradation capability for PCDFs. (C) 1998 Elsevier Sc ience Ltd. All rights reserved.