Per/Polyfluoroalkyl Substances (PFASs) in a Marine Apex Predator (White Shark, Carcharodon carcharias) in the Northwest Atlantic Ocean

Abstract

Per/polyfluoroalkyl substances (PFASs) are ubiquitous, highly persistent anthropogenic chemicals that bioaccumulate and biomagnify in aquatic food webs and are associated with adverse health effects, including liver and kidney diseases, cancers, and immunosuppression. We investigated the accumulation of PFASs in a marine apex predator, the white shark (Carcharodon carcharias). Muscle (N = 12) and blood plasma (N = 27) samples were collected from 27 sharks during 2018−2021 OCEARCH expeditions along the eastern coast of North America from Nova Scotia to Florida. Samples were analyzed for 47 (plasma) and 43 (muscle) targeted PFASs and screened for >2600 known and novel PFASs using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Perfluoroalkyl carboxylates with carbon chain-length C11 to C14 were frequently detected above the method reporting limits in plasma samples, along with perfluorooctanesulfonate and perfluorodecanesulfonate. Perfluoropentadecanoate was also detected in 100% of plasma samples and concentrations were estimated semiquantitatively as no analytical standard was available. Total concentrations of frequently detected PFASs in plasma ranged from 0.56 to 2.9 ng mL −1 (median of 1.4 ng mL −1 ). In muscle tissue, nine targeted PFASs were frequently detected, with total concentration ranging from 0.20 to 0.84 ng g −1 ww. For all frequently detected PFASs, concentrations were greater in plasma than in muscle collected from the same organism. In both matrices, perfluorotridecanoic acid was the most abundant PFAS, consistent with several other studies. PFASs with similar chain-lengths correlated significantly among the plasma samples, suggesting similar sources. Total concentrations of PFASs in plasma were significantly greater in sharks sampled off of Nova Scotia than all sharks from other locations, potentially due to differences in diet. HRMS suspect screening tentatively identified 13 additional PFASs in plasma, though identification confidence was low, as no MS/MS fragmentation was collected due to low intensities. The widespread detection of long-chain PFASs in plasma and muscle of white sharks highlights the prevalence and potential biomagnification of these compounds in marine apex predators.

Accumulation of Per- and Polyfluoroalkyl Substances (PFAS) in Coastal Sharks from Contrasting Marine Environments: The New York Bight and The Bahamas

“…Sharks are meso-to-apex predators, have diverse functional roles, and are often considered sentinels for evaluating the overall health of marine ecosystems. − Due to their potential longevity, slow growth, large size, and high trophic level, the tissues of many shark species have been found to contain relatively high concentrations of diverse persistent organic pollutants (e.g., polychlorinated biphenyls [PCBs], dichloro-diphenyl-trichloroethane [DDT], and methylmercury [MeHg]) owing to prolonged bioaccumulation and biomagnification. − However, only a handful of studies have reported PFAS concentrations in sharks (e.g., blue sharks (Prionace glauca), tiger sharks (Galeocerdo cuvier), bull sharks (Carcharhinus leucas), and white sharks (Carcharodon carcharias)) sampled from the Mediterranean Sea, Atlantic, and Indian Oceans, − which often contain long-chain PFAS. For example, perfluorotridecanoic acid (PFTrDA), perfluoroundecanoic acid (PFUnA), and perfluorooctanesulfonate (PFOS) were predominant compounds in muscle tissue, followed by perfluorotetradecanoic acid (PFTA) and perfluorododecanoic acid (PFDoA). ,, On average, total detected concentrations of PFAS (∑PFAS) ranged from 0.14 to 17.9 ng g –1 (wet weight, ww; muscle tissue), with the highest concentration detected in angular roughsharks (Oxynotus centrina) sampled in the Mediterranean Sea .…”

“… 31 Concentrations of ∑PFAS in basking sharks ( Cetorhinus maximus ) also varied among tissue types and were higher in skin and liver than in muscle. 28 One recent study reported higher ∑PFAS concentrations in blood plasma than in muscle tissue of white sharks in the Northwest Atlantic Ocean, 30 and another recent study revealed interspecific variation in the ∑PFAS of plasma in four small coastal shark species along the South Atlantic Bight. 32 While intertissue differences in PFAS are common in sharks, additional drivers of bioaccumulation patterns remain speculative.…”