Exploring profiles of per- and polyfluoroalkyl substances (PFAS) in a long-lived Arctic predator: The Greenland shark...

Per- and polyfluoroalkyl substances (PFAS) are widespread, highly persistent and mobile contaminants that accumulate and biomagnify in marine food webs. Although PFAS have been reported in several marine predators, data from long-lived Arctic species remain scarce. Here, we explored PFAS profiles in Greenland sharks (Somniosus microcephalus), from Svalbard, Norway, to evaluate their occurrence in one of the longest-lived vertebrates; many, if not all the sampled individuals in this study are likely to have been born before PFAS introduction. Plasma analysis from sharks (n = 43) revealed a range of long-chain PFAS, dominated by linear-perfluorooctane sulfonate (L-PFOS) and long-chain perfluoroalkyl carboxylic acids (PFCAs; C9-C14). The total concentration of detected PFAS (∑PFAS) ranged from 0.61 to 10.73 ng/g, with a median of 3.27 ng/g plasma. However, females (n = 27) contained higher concentrations of ∑PFAS, with median and range (4.13; 0.79-10.73 ng/g) values higher than males (n = 16) with ∑PFAS (2.33; 0.61-8.58 ng/g) (p < 0.05). Spearman correlation run on biological parameters showed that PFAS concentrations were positively correlated with girth and body mass but showed no association with the body length of these sharks. When compared to plasma PFAS in other marine predators from Svalbard, Greenland sharks showed lower levels except in select benthic-feeding pinnipeds, which had the lowest levels of PFAS particularly PFCAs (C10-C14). However, Greenland sharks are among the highest levels of ∑PFAS across the global cohort of shark plasma studied to date. Our findings highlight that sharks that live in cold and deep waters of the Arctic are exposed to PFAS, emphasizing the need for continued monitoring of emerging contaminants in remote environments and long-living predators.