Australian dolphins record world’s highest ‘forever chemicals

Dolphins, apex predators, accumulate high toxin levels, acting as sentinels for ecosystem health. Persistent pollutants, notably PFAS (per- and polyfluorinated substances), labeled “forever chemicals,” pose global environmental and potential human health risks. In recent research, Australian waters reveal dolphins with the world’s highest PFAS concentrations. A critically endangered Burrunan dolphin exhibited liver concentrations 30% higher than any recorded. Indigenous to southeast Australia, the species faces unknown health consequences, raising concerns. This highlights the urgent need for comprehensive study and environmental management to comprehend and address the ramifications of these enduring pollutants.

The case of the Burrunan dolphin
The Burrunan dolphin, identified as a distinct species in 2011 with fewer than 200 individuals, faces a critical situation. Residing in coastal Victoria, Australia, this critically endangered species exhibits PFAS concentrations 50–100 times higher than other regional dolphins, marking the highest globally reported levels. Liver concentrations in 90% of these dolphins surpassed thresholds linked to liver toxicity and immune response alterations (1,020–19,500 nanograms per gram). These unprecedented PFAS levels pose a significant threat to the survival of the Burrunan dolphin, emphasizing the urgent need for conservation measures and understanding the broader environmental impact.

Results from Australia and around the world
High PFAS concentrations, notably PFOS, were found in Burrunan dolphins off Australia’s coast. PFOS, a globally restricted compound, was used in firefighting foams until the early 2000s. Despite Australia not producing PFOS, its import continues for specific purposes. Leaking septic and wastewater systems contribute to PFAS runoff. Similar dolphin studies across Australia reveal elevated PFOS levels, signaling potential widespread contamination. Understanding PFAS sources, especially legacy ones, is crucial for mitigating oceanic and estuarine consequences, emphasizing the need for ongoing research into the origin and impact of these persistent pollutants.

Isn’t PFOS getting banned anyway?
The Australian government aims to regulate PFOS and two other PFAS, marking progress in addressing these persistent pollutants. However, the challenge with “forever chemicals” lies in their enduring presence. Substitutes for PFOS, initially considered less harmful, pose unforeseen risks, such as biomagnification. In Burrunan dolphins, PFMPA, PFECHS, and 6:2 Cl-PFESA were also detected, revealing the accumulation of emerging and replacement compounds in waterways beyond historical usage, emphasizing the complexity of addressing the impact of these substances.

It’s not too late
Dolphins are the “canary in the coal mine” for coastal ecosystems. They live their lives in these inshore waterways and they consume tonnes of fish within their lifetimes. Finding these alarming contaminant concentrations is an important first step to highlighting the problem.

So now we know there’s a problem, we need to ask why. Then we need to determine what can be done about it. The next step is mapping sources of PFAS so we can more effectively manage this threat to our wildlife and ecosystems.