A risk analysis of legacy pollutants: PCBs, PBDEs and new emerging pollutants in Salish sea killer whales

Both Resident killer whales and their main food source, Chinook salmon, contain high concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Biopsies of killer whale and Chinook salmon samples have not measured these and other hazardous chemicals since 2009 and 2000, respectively. For this study, current samples of Resident killer whales and Chinook salmon were collected and analysed for PCBs, PBDEs, hexabromocyclododecane and other detected flame- retardants. A risk-based assessment was conducted to identify which pollutants were of greatest concern to the health of killer whales. PCBs were found to be the main contaminant of concern, although PBDEs are of growing concern due to a significant increase in concentration in killer whales over time. This study contributes to the second stage of the recovery strategy for Resident killer whales, within the Action Plan implemented by the Department of Fisheries and Oceans Canada.