Seabirds in one of the remotest parts of the planet are being exposed to a wide range of forever chemicals, scientists have discovered.
Researchers have found ‘forever chemical’ compounds in seabirds from the remote Southern Ocean - providing further evidence highlighting the global reach of per- and polyfluoroalkyl substances (PFAS), known as forever chemicals because they do not easily break down in the environment.
Although there are previous studies revealing PFAS exposure in sub-Antarctic seabirds, these are few in number and have mostly looked for a more limited target list of chemicals than this latest research.
The new study, recently published in ACS Environmental Au, raises concerns because scientists found both the presence of both long-banned ‘legacy’ compounds, such as PFOS (perfluorooctane sulfonate), and chemicals that were introduced as replacements, including HFPO-DA and ADONA, in liver samples of three species of sub-Antarctic seabirds.
PFAS are a large group of chemicals, several of which have been shown to bioaccumulate and cause adverse effects. As a result of restrictions on some of these chemicals, such as through the Stockholm Convention, replacement chemicals were introduced - however these are also now being detected in the environment and wildlife.
The researchers say biomonitoring of PFAS is crucial in understanding their global distribution and for detecting emerging chemicals of concern.
In this study, scientists, targeting a list of nearly 40 chemical compounds, discovered the presence of 22 different per- and polyfluoroalkyl substances (PFAS) in liver tissue samples taken from three species of seabirds – black-browed albatrosses, common diving petrels and white-chinned petrels.
The samples were from birds caught in fishing gear or that collided with fishing vessels between 2004 and 2014 from two separate sampling areas of the south-west Atlantic - the Falkland Islands and South Georgia.
The research team, led by scientists at Lancaster University and involving researchers at the British Antarctic Survey and CEFAS (Centre for Environment, Fisheries and Aquaculture Science), found that PFAS compounds were present across samples from all three bird species despite these birds inhabiting a remote part of the planet, far from major PFAS sources.
Dr Andrew Sweetman, Reader of Environmental Chemistry at Lancaster University, said: “Seabirds are apex predators and can therefore be used as bioindicators of marine pollution. Their contamination tells us what is happening in the ecosystems they inhabit.
“Our findings add to growing evidence that PFAS contamination is not restricted to industrialised regions — even some of the planet’s most remote ecosystems are now showing the legacy of these chemicals.
“Detection of these compounds in sub-Antarctic samples far from where these chemicals are produced, provides crucial evidence for long-range transport and bioaccumulation, particularly for compounds that are transported in the atmosphere.”
While concentrations of chemicals varied significantly across samples, the researchers found that many of the chemical profiles within the seabird liver samples were strikingly similar: comprising mainly perfluorooctane sulfonic acid (PFOS) (~80%) and perfluoroalkyl carboxylic acids (PFCAs) (~15%).
Importantly, the researchers say their findings suggests that PFAS fingerprints, i.e., the pattern of the chemicals, are similar throughout the southern Atlantic Ocean. This is despite the range of migration destinations of these different seabird species, which covers the Patagonian Shelf off South America to the Benguela upwelling off south-west Africa.
Imogen Bailes, lead author and PhD researcher at Lancaster University, said: “This study provides evidence for the exposure and accumulation of both legacy and emerging PFAS in three species of sub-Antarctic seabirds, highlighting the value of biomonitoring in remote environments.
“We found evidence that even these newer replacement compounds are travelling and persisting in these very remote marine environments.
“Our results imply that the approach of placing restrictions on a chemical-by-chemical basis is unlikely to result in an effective reduction in PFAS burdens in wildlife and so regulators may need to consider the introduction of more comprehensive restrictions to prevent these persistent chemicals from accumulating in the environment.”
The study is outlined in the paper ‘Per- and Polyfluoroalkyl Substances (PFAS) in Sub-Antarctic Seabirds: Insights into Long-Range Transport and Bioaccumulation of Legacy and Replacement Chemicals’.