Toxic PFAS Chemical Found in Sea Lions and Fur Seal Pups

Researchers have recently discovered that toxic PFAS chemical (Per- and polyfluoroalkyl substances) that the NSW government has recently partially banned for use as a firefighting foam, has been found in the pups of endangered Australian sea lions and in Australian fur seals. The finding represents another possible blow to Australian sea lions’ survival. Hookworm and tuberculosis already threaten their small and diminishing population, which has fallen by more than 60 percent over four decades.


PFAS chemicals have been reported to cause cancer, reproductive and developmental defects, endocrine disruption and can compromise immune systems. Exposure can occur through many sources including through contaminated air, soil and water, and common household products containing PFAS. In addition to being used in firefighting foam, they are frequently found in stain and water repellents, polishes, paints and nonstick coatings on cookware.  Despite South Australia banning the use of PFAS-containing firefighting foams in 2018, these chemicals persist and don’t easily degrade in the environment.

Study overview

This is the first study to report concentrations of PFAS in seals and sea lions in Australia. The new research — part of a long-term health study of seals and sea lions in Australia — identified the PFAS chemicals in animals at multiple colonies in Victoria and South Australia from 2017 to 2020. The research was partly conducted on site at the animals’ colonies, with later testing of animal livers at the National Measurement Institute in Sydney. The livers were analyzed using a complex method called high-performance liquid chromatograph/triple quadrupole mass spectrometry. At its most basic, this method ionises a molecular compound and then separates and identifies the components based on their mass-to-charge ratio.  In this way, specific chemicals and their abundance can be measured.

Results overview

The PFAS chemicals were detected in pups, juvenile animals and one adult. There was also evidence of transfer of the chemicals from mothers to newborns.  PFAS concentrations in some animals were comparable to those in marine mammals in the northern hemisphere including southern sea otters and harbor seals.  Particularly high concentrations of the chemicals were found in newborns — transferred during gestation or via their mothers’ milk. “This is particularly concerning, given the importance of the developing immune system in neonatal animals,” said research co-lead, Dr. Rachael Gray from the Sydney School of Veterinary Science.

The researchers believe the seals and sea lions ingested the chemicals through their fish, crustacean, octopus and squid diets.


“While it was not possible to examine the direct impacts of PFAS on the health of individual animals, the results are crucial for ongoing monitoring. With the Australian sea lion now listed as endangered, and Australian fur seals suffering colony-specific population declines, it is critical that we understand all threats to these species, including the role of human-made chemicals, if we are to implement effective conservation management.”

-Dr. Rachael Gray, researcher, Sydney School of Veterinary Science

Journal Reference:  Shannon Taylor, Michael Terkildsen, Gavin Stevenson, Jesuina de Araujo, Chunhai Yu, Alan Yates, Rebecca R. McIntosh, Rachael Gray. Per and polyfluoroalkyl substances (PFAS) at high concentrations in neonatal Australian pinnipeds. Science of The Total Environment, 2021; 786: 147446 DOI: 10.1016/j.scitotenv.2021.147446