First assessment of persistent organic pollutant contamination in blubber of Chilean blue whales from Isla de Chiloé southern Chile

Persistent organic pollutants (POPs) were assessed for the first time in blue whales from the South Pacific Ocean. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane and its main metabolites (DDTs), were determined in 40 blubber samples from 36 free-ranging individuals and one stranded, dead animal along the coast of southern Chile between 2011 and 2013. PCBs were the most abundant pollutants (2.97–975 ng/g l.w.), followed by DDTs (3.50–537 ng/g l.w.), HCB (nd–77.5 ng/g l.w.) and PBDEs (nd–33.4 ng/g l.w). There was evidence of differences between sexes, with lower loads in females potentially due to pollutants passing to calves. POP concentrations were higher in specimens sampled in 2013; yet, between-year differences were only statistically significant for HCB and PBDEs. Lower chlorinated (penta > tetra > tri) and brominated (tetra > tri) congeners were the most prevalent among PCBs and PBDEs, respectively, mostly in agreement with findings previously reported in blue and other baleen whales. The present study provides evidence of lower levels of contamination by POPs in eastern South Pacific blue whales in comparison to those reported for the Northern Hemisphere.J. M-A acknowledges his contract under project 15CAES004. Ms. Alicia Jiménez Almarza is greatly acknowledged for her valuable help in sample analysis. Alba Vicente is thanked for the graphical abstract. We thank the Directorate General of theMaritime Territory andMerchant Marine (DIRECTEMAR) from the Chilean Navy and the Ministry of Foreign Affairs of Chile for their Official Support to the Alfaguara (Chilean blue whale) Project. We would also like to thank the valuable support of Global Greengrants Fund, Rufford Foundation, Mohamed Bin Zayed Species Conservation Fund and Pacific Whale Foundation to the Alfaguara Project. We thank Moira Brown for providing the crossbow to collect biopsies and Instituto de Conservación de Ballenas (Argentina) for financial support to MS. Special thanks to José Aviles Puen, skipper of the Alfaguara research vessel for all the marine surveys conducted to get blue whale data and samplesPeer Reviewe