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 sites along the Great Barrier Reef were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Relatively high levels of PCDDs were determined in all three dugongs. In particular OCDD, the PCDD/F congener that is usually considered the least bioavailable of all 2,3,7,8 substituted congeners, was found at levels higher than reported for other marine mammals. Tissue accumulation of PCDDs by dugongs may be a consequence of sediment and/or seagrass ingestion during feeding, microbial biotransformation of PCDD precursors in the animalʹs hindgut or, alternatively, the possession of a selective degradation capability for PCDFs.