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Researchers have found toxic “forever chemicals” on the remote southern coastline of Argentina — with the help of some avian assistants.
Scientists fitted Magellanic penguins with silicone passive sampler (SPS) bands, a non-invasive tool that absorbs chemicals from water, air and surfaces.
“We’ve been looking for alternatives to measure pollution on these species for long time,” says Ralph Vanstreels, wildlife veterinarian at University of California-Davis and co-author of a study published in March in the journal Earth: Environmental Sustainability. Inspired by wristband samplers that humans can wear to measure exposure to contaminants, he contacted Diana Aga, an analytical chemist at University at Buffalo, with a “crazy idea”: “We place other devices on the penguin, so why not silicon bands?”
Over three breeding seasons, the interdisciplinary team gathered samples from 55 penguins. More than 90% of the bands detected polyfluoroalkyl substances (PFAS) — a group of synthetic chemicals used in a huge range of everyday products, from non-stick cookware and raincoats, to firefighting foam and pharmaceuticals. PFAS are resistant to water, grease, chemicals and heat, but that durability makes them hard to break down. They build up in the environment and our bodies, and decades of research has linked them to health risks including reproductive and developmental issues, and cancers.
“The concentration (of PFAS) is not high, but we found it consistently,” says Vanstreels. “It shows that even in this very remote, not very inhabited region, these animals are getting exposure on a consistent basis.”
Traditional ocean monitoring is “expensive and inefficient,” says Vanstreels, requiring a boat and a lengthy expedition with a crew. But penguins forage widely in the ocean, providing a natural opportunity to passively collect data.
“(The penguins) tell you which parts of the ocean are important, so that you’re not sampling at random the whole ocean,” he adds.
SPS bands are typically worn by people as wristbands, but attaching standard bands to penguin wings would cause drag. Instead, the band was modified to include a small piece of stainless-steel wiring, allowing the field team to tailor the band to the width of the penguin’s leg.
“Making them to size for each individual penguin gives us more confidence that it’s not going to fall off, and it’s not going to cause discomfort,” says Vanstreels.
The process of fitting the band took two wildlife veterinarians around three minutes, minimizing distress to the birds, says Vanstreels, adding that after attaching the band, the team monitored from a distance to make sure the penguins were comfortable.
Of the 57 birds fitted with bands for the study, just one had its band removed after Vanstreels suspected some discomfort, and only one band went missing after deployment.
After the bands were collected, Aga’s lab in Buffalo analyzed the samples using mass spectrometry. There are more than 7 million unique variants of PFAS, so to narrow the study’s focus, the analysis targeted a mix of 24 legacy PFAS — many of which have been banned or are no longer produced — and new “replacement” PFAS, many of which are not regulated, says Aga, lead chemist on the study.
“There’s a rise in the replacement PFAS, which makes sense, but it’s also concerning,” says Aga. “We thought that replacement chemicals would be less persistent, but it’s not — it’s just as bioaccumulative, and according to epidemiologists and toxicologists, they are just as toxic as the legacy PFAS.”
The negative health impact of PFAS on wildlife has been documented in hundreds of studies, and analysis from the Environmental Working Group (EWG), a US-based nonprofit, has identified PFAS in more than 600 species.
But data on many species is limited because traditional sampling methods, like blood or tissue samples, are invasive.
David Megson, an environmental chemist at the UK’s Manchester Metropolitan University, who is not involved with the research, says that the new method offers an innovative way to gather information about wildlife and its environment.
“When we do research on animals, the way to get the best quality data is a lot of the time is to kill the animal, which is just really horrible for a lot of us scientists that do this, because we care a lot about the environment,” says Megson. “Any technique that is moving us away from sacrificing animals and measuring organs, I think is a really positive thing.”
While PFAS studies in North America, Europe and China are abundant, “there’s been very, very little in South America, Africa, the Global South,” says Megson, adding that the inclusion of emerging PFAS in the analysis was “interesting to see.”
Megson notes that the results of the study don’t directly show how much PFAS is accumulating in a penguin’s body or its impact on the bird’s health, but adds that the SPS bands could be a “complementary technique” to better understanding the environment they live in.
“Their main route of PFAS exposure is probably going to be from the fish that they’re eating, not the general background in their environment,” says Megson. “If you could use the wristband to see what’s going on around them, take a sample of blood, take a sample of the food that they’re eating, then we can understand a lot more about that whole environment that they’re exposed to, and where the PFAS are coming from.”
While Magellanic penguins are not endangered, 13 of the 18 recognized penguin species have declining global populations, or are listed as threatened.
“There’s other penguins that live in areas that are even more densely inhabited,” says Vanstreels, pointing to the critically endangered African penguin in Namibia and South Africa, and the little penguin in Australia and New Zealand. “Those are examples of penguins that are living right next to urban centers, and potentially large areas of industrial activity where this kind of pollution might be more significant.”
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Vanstreels and Aga hope this study can be a “proof of concept” for further research, and plan to test the method on other wildlife, such as cormorants — seabirds that can dive more than 150 feet below the water’s surface.
And for the penguins, Vanstreels hopes to continue monitoring the bird’s exposure to pollution, particularly on its winter migration north to Uruguay and Brazil.
“There is no way of protecting penguins in Patagonia without dealing with global problems in terms of pollution, in terms of industry, in terms of how we dispose of chemicals,” says Vanstreels.