Dolphins and whales have ‘no place to hide’ from forever chemicals, warns new study

Marine mammals aren’t “immune from the burden” of toxic forever chemicals, even if they live below the ocean’s surface.

New research published in Science of the Total Environment has raised alarm bells over the long-term health of marine species, after deep-sea dolphins and whales were found with “unprecedented” levels of polyfluoroalkyl substances (PFAS) contamination.

These are human-made chemicals found in items such as stain-resistant fabrics, non-stick cookware and food packaging. They are often referred to as 'forever chemicals' because they take thousands of years to degrade naturally.

‘No place to hide’ from PFAS

While many assume that a deep-sea home provides protection from PFAS, scientists found that habitats are actually a poor predictor of concentration levels.

It comes after scientists analysed tissues from 127 animals across 16 species of toothed whales and dolphins in New Zealand’s water. This included bottlenose dolphins and 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.

Dr Katharina Peters, a marine ecologist and research leader of the University of Wollongong's (UOW) Marine Vertebrate Ecology Lab, explains that these animals were selected as whales and dolphins are often considered “indicator species” that 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,” Peters adds.

“Our analyses show that this is not the case. There really seems to be no place to hide from PFAS.”

A ‘threat’ to marine diversity

The extent to which PFAS contamination can harm wildlife remains unknown, but researchers have warned it may disrupt their immune and reproductive systems.

Back in 2022, researchers found autoimmune disorders similar to lupus in alligators living in contaminated waters in North Carolina.

In humans, PFAS now contaminates the bodies of nearly all Europeans, including children and pregnant women, and has been linked to a slew of problems such as cancer, infertility, thyroid disease and immune system suppression.

"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," adds study co-author Dr Frédérik Saltré, a researcher with the University of Technology Sydney (UTS) and the Australian Museum.

The study concludes that further investigations are now required to understand the outcomes for individuals and populations exposed to PFAS.