Studying penguin virology in Antarctica
ASU researchers lead in discovery of new viruses in Antarctic penguins, expanding knowledge of polar ecosystems
Adélie penguins gather on the lip of a frozen shelf, preparing to plunge into the water below. Agile and fast underwater, Adélies rely on krill and small fish to fuel their relentless daily commutes between land and sea. Photo courtesy Arvind Varsani/ASU.
An international team led by Arizona State University virologist Arvind Varsani has discovered dozens of previously unknown viruses in Adélie, Chinstrap and Gentoo penguins from colonies across Antarctica.
The study, published in Microbial Genomics, by first author Melanie Regney, a PhD student in ASU’s School of Life Sciences and Biodesign Center for Fundamental and Applied Microbiomics, identified 31 polyomaviruses and four papillomaviruses, including two that are new to science.
The findings expand what is known about Antarctic wildlife health and evolution, showing that penguin species host distinct viral lineages that reflect the geographic structure of breeding colonies in Antarctica. Researchers say the work provides a critical baseline for understanding how Antarctic ecosystems may respond to environmental change.
Revealing a hidden viral world
An international team of scientists from ASU, Point Blue Conservation Science, Oregon State University, H.T. Harvey & Associates, Museo Nacional de Ciencias Naturales and University of Alcalá in Spain — together called Penguin Science — conducted the study. The team’s findings reveal a hidden layer of biological diversity in one of the planet’s most extreme environments.
“There’s very little known about Antarctic virology in terms of these animals that breed in this region,” said Varsani, a virologist in ASU’s School of Life Sciences and Biodesign Center for Fundamental and Applied Microbiomics. “Over the last 15 years, we've been putting in quite a bit of effort to try and understand the viral landscape associated with Antarctic animals, which include penguins, skuas, seals and ice fish.”
The research expands knowledge of viruses that circulate among penguin species and how wildlife and microbes co-evolve. Varsani said the team focused on polyomaviruses and papillomaviruses, DNA virus groups both known to infect vertebrates and often show host lineage specificity.
“Therefore, spatial and temporal datasets of polyomaviruses and papillomaviruses associated with Antarctic penguins can enhance our understanding of virus-host interactions and viral evolution in these flightless birds compared to flying birds, as well as geographical movement or restriction by proxy of identifying viral lineages,” Varsani said.
Viral diversity across penguin colonies
“With the polyomaviruses, what we're seeing is also a trend based on groupings, or species,” Varsani said. “These viruses seem to have been embedded in a population, and as the population has bred in different parts of the continent, the virus lineages appear to be circulating within those populations.”
The researchers found that certain viral variants appeared only in specific penguin species or locations, suggesting strong links between host species and geography. In two Gentoo penguins, the team found two polyomavirus variants at the same time, marking the first evidence of co-occurrence in penguins.
Samples were collected from more than 400 penguins between 2021 and 2024, including Adélie, Chinstrap, Gentoo and Emperor penguins. Field sites spanned penguin breeding colonies on Ross Island in the Ross Sea region and multiple locations on the Antarctic Peninsula. None of the sampled penguins showed signs of illness or visible lesions.
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Emperor penguins and their fluffy grey chicks huddle on the ice as a solitary Adélie penguin wanders into their midst. Scenes like this provide the backdrop for Arvind Varsani’s research on the hidden viral networks linking Antarctica’s wildlife.
Photo courtesy Arvind Varsani
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Emperor penguins form tight family units to survive the brutal Antarctic winter. While one adult shields the chick against the cold, the other treks long distances across the ice to feed at sea.
Photo courtesy Arvind Varsani
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Gentoo penguins tend their fluffy chicks on an ice-free ridge. Gentoos are the fastest swimming penguins in the world. Their streamlined, torpedo-shaped bodies can reach speeds over 20 miles per hour as they dart through the frigid Southern Ocean.
Photo courtesy Arvind Varsani
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Adélie penguins gather at their rocky breeding colony, where noisy chicks jostle for attention and food. These compact, high-energy birds build simple pebble nests and defend them fiercely from their equally determined neighbors.
Photo courtesy Arvind Varsani
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Adélie chicks press close to a parent at a rocky Antarctic nesting site. These colonies are loud, energetic places, with chicks constantly jostling for warmth and food.
Photo courtesy Arvind Varsani
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Snow drifts across the rocks as a Chinstrap penguin stands alone in the muted Antarctic light. Its crisp, black chin mark makes the species instantly recognizable on the storm-shaped coasts of the Southern Ocean.
Photo courtesy Arvind Varsani
A decades-long collaboration
The study is part of a long-term collaboration between researchers at Point Blue Conservation Science, H.T. Harvey & Associates Ecological Consultants, Oregon State University and ASU, with funding and logistical support from the National Science Foundation and Ministerio de Economía, Comercio y Empresa.
This year marks Penguin Science’s 30th year of research at penguin breeding colonies on Ross Island. Varsani has been part of the team for the past 15 years and has joined the field team in Antarctica for eight research seasons.
“Antarctic virology is poorly documented because limited work has been done in this area,” he said. “We need to collect a significant amount of this baseline data to even understand broader impacts as a consequence of what might be happening when there are drastic changes in the ecosystem.”
Connecting viral diversity and environmental change
While Varsani said the team cannot yet determine how climate change directly influences virus dynamics in penguins, they do know environmental shifts can affect overall penguin health.
“Due to environmental stresses, would the animals also be a lot more stressed? And would they succumb to much more severe disease outcomes?” he said. “When our immune systems are down or we’re stressed, we kind of have a lot more negative impacts on our health. It’s a similar concept here.”
The study’s findings highlight the importance of baseline viral monitoring in understanding Antarctic and other ecosystems.
“Ultimately, we can start using certain viral signatures to actually look at trophic interactions or even movement of the penguins between two different geographical locations,” Varsani said.
Regney said being part of the project has deepened her appreciation for Antarctic science: “I am fortunate to be part of this research team,” she said. “Antarctica is an amazing place with diverse fauna, and I am passionate about Antarctic virology.”