World-first study shows deep sea habitat does not protect marine mammals from devastation of PFAS contamination
Groundbreaking research has revealed that marine mammals who live far below the ocean's surface are not immune from the burden of toxic forever chemicals, with whales and dolphins showing unprecedented levels of PFAS contamination.
Dr Katharina Peters, a marine ecologist and research leader of the University of Wollongong's (UOW) Marine Vertebrate Ecology Lab, contributed to the world-first study, led by Te Kunenga ki Pūrehuroa Massey University. The findings challenge the assumption that a deep-sea habitat offers protection from human-made per- and polyfluoroalkyl substances, otherwise known as PFAS.
"Whales and dolphins are considered indicator species because they reflect their ecosystem. We expected that species feeding mainly in deep water, like sperm whales, would have lower PFAS contamination than coastal species like Hector's dolphins which are closer to pollution sources. Our analyses show that this is not the case: there really seems to be no place to hide from PFAS," Dr Peters said.
Published in Science of the Total Environment, the findings raise concerns about the long-term health of marine species and the invisible legacy that forever chemicals are leaving in the environment. PFAS are human-made chemicals that accumulate through the food chain and can disrupt immune, endocrine and reproductive systems, raising concerns for both individual and population health in humans and animals, including cetaceans.
The scientists analysed tissues from 127 animals across 16 species of toothed whales and dolphins in New Zealand waters, from bottlenose dolphins to deep-diving sperm whales. For eight of the 16 species, including New Zealand's endemic Hector's dolphin and three species of beaked whales, this was a global first for PFAS assessment. The researchers looked at how the acquisition of forever chemicals varied according to species, sex, age and the habitat in which they predominantly live and feed.
Study co-author Dr Frédérik Saltré, a researcher with the University of Technology Sydney (UTS) and the Australian Museum, said they found that habitat is a poor predictor of PFAS concentrations.
"Even offshore and deep-diving species are exposed to similar levels of PFAS, highlighting how widespread pollution, compounded by climate-driven stressors, poses a growing threat to marine biodiversity," he said.
The trans-Tasman collaboration involving UOW, Massey University, Manaaki Whenua — Landcare Research, University of Auckland, UTS, and the Australian Museum, is the first of its kind to assess PFAS across a wide range of species, over the same period, living in different marine habitats.
About the research
'No place to hide: Marine habitat does not determine per- and polyfluoroalkyl substances (PFAS) in odontocetes', by Karen Stockin, Katharina Peters, Frédérik Saltré, Gabriel Machovsky-Capuska, Emma Betty, Louis Tremblay, Shan Yi, was published in Science of the Total Environment: https://doi.org/10.1016/j.scitotenv.2025.180701
