A chemical that the NSW government has recently partially banned in firefighting has been found in the pups of endangered Australian sea lions and in Australian fur seals.
The new research—part of a long-term health study of seals and sea lions in Australia—identified the chemicals in animals at multiple colonies in Victoria and South Australia from 2017 to 2020.
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.
As well as in pups, the chemicals (Per- and polyfluoroalkyl substances – ‘PFAS’) were detected in juvenile animals and in an adult male. There was also evidence of transfer of the chemicals from mothers to newborns.
The study—published in Science of The Total Environment—is the first to report concentrations of PFAS in seals and sea lions in Australia.
PFAS 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 repellents, polishes, paints and coatings.
The researchers believe the seals and sea lions ingested the chemicals through their fish, crustacean, octopus and squid diets.
Despite South Australia banning the use of PFAS-containing firefighting foams in 2018, these chemicals persist and don’t easily degrade in the environment. They have not been banned in Victoria.
PFAS concentrations in some animals were comparable to those in marine mammals in the northern hemisphere including southern sea otters and harbour 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.
“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.”
The original version of this story is published on the News page of the University of Sydney website.