Analysis of persistent organic pollutants and heavy metals in mysticetes from the United Arab Emirates

Chemical pollution is a major threat that can increase the mortality and lower the reproductive success of cetaceans. In this study we assess, for the first time, the level of contamination of selected priority pollutants consisting of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals in whales found stranded in the United Arab Emirates. The samples included five Bryde's whales (Balaenoptera edeni) and one humpback whale (Megaptera novaeangliae) from the Arabian Gulf and one blue whale (Balaenoptera musculus) from the Gulf of Oman. None of the 18 OCPs tested for were detected. Of the 20 PCB congeners tested for, only one was detected in two (40%) Bryde's whales.The concentrations of trace elements and heavy metals were lower than reported in baleen whales from the southern hemisphere. PAHs, the predominant pollutants in this study, were detected in the tissues of all examined specimens. The predominance of low molecular weight PAHs over high molecular weight PAHs suggests that PAH exposure may have been primarily from petrogenic sources. The amputation of the tail fluke in one case and bruising of a second whale suggest trauma and marine debris entanglement may have contributed to death in at least two cases. We observed no evidence of marine debris ingestion when such examinations were possible

Automated summary

Chemical pollution poses a significant threat to cetaceans, and this study investigates the contamination levels of selected priority pollutants in stranded whales in the United Arab Emirates. PAHs were the predominant pollutants detected, while heavy metal concentrations were lower. Trauma and marine debris entanglement may have contributed to death in some cases.