Explained | Antarctica's First Bird Flu Outbreak: Are Penguins At Risk?

Scientists have confirmed the presence of a deadly type of bird flu on the mainland of Antarctica for the first time. Heightened concerns have arisen regarding the potential risk to the southern region's ecosystem.

This area serves as the breeding ground for more than 100 million birds, including hundreds of thousands of penguins found nowhere else on Earth.

Avian Flu Detected in Antarctica's Skua Seabirds

Two dead skua seabirds were discovered by Argentine scientists near its base, Primavera, and a scientific research station situated on the Antarctic Peninsula. The presence of the H5N1 avian virus was confirmed in the samples of the deceased birds by the Spanish National Research Council (CSIC) on 24 February.

"This discovery demonstrates for the first time that the highly pathogenic avian influenza virus has reached Antarctica, despite the distance and natural barriers that separate it from other continents," scientists from the Severo Ochoa Molecular Biology Center of the Higher Council for Scientific Research stated in a press release on Sunday.

"Analysis has conclusively shown that the birds were infected with the H5 subtype of avian influenza and at least one of the dead birds contained the highly pathogenic avian influenza virus," CSIC said, as per Reuters.

According to The Washington Post, CSIC added that samples from the two deceased skuas were obtained by scientists using "maximum security measures to prevent transmission of the virus to people," sending them by ship to the Spanish base on Deception Island for testing.

Are Penguins at Risk?

Since 2020, when the highly infectious virus emerged again, it has devastated both wild and domestic animals across continents, except Australia. The flu has proven potent enough for transmission from birds to mammals, resulting in the deaths of polar bears, fur seals, and elephants.

Last year, in October, the Scientific Committee on Antarctic Research conducted a risk assessment of the effects of bird flu spreading to the continent, finding that penguins, birds of prey, sheathbills, and giant petrels are most at risk, followed by fur seals, sea lions, skuas, and gulls.

There are hundreds of thousands of penguins on the Antarctic continent and nearby islands, known for waddling together in packed colonies. The current arrival of H5N1 avian influenza highlights the risk to colonies in the ecosystem. In January this year, over 200 Gentoo penguin chicks and several adults were found dead off the Falkland Islands coast - but not in the actual Antarctic territory.

Antarctica has never experienced an outbreak of bird flu before, resulting in very low immunity among its residents. The unexpected flu hit could even lead to mass mortality. Massive, densely packed bird colonies and highly threatened species coexist in Antarctica, making the potential impacts of a virus outbreak devastating, according to Christian Walzer, a wildlife veterinarian and executive director of health at the Wildlife Conservation Society.

Scientists in a preprint research paper released in November 2023 expressed fears that the outbreak could cause "one of the largest ecological disasters of modern times." Penguins in Antarctica are not only facing the risk of a virus outbreak but also rising temperatures, which deplete the sea ice they need to survive.

The US Fish and Wildlife Service warned in 2022 that the continent's emperor penguins are threatened with extinction due to climate change. Researchers from Spain have advised preparing national polar programs to avoid the transmission of infections to humans.

What is the H5N1 strain?

A highly pathogenic avian influenza (HPAI) virus known as H5N1 is responsible for the outbreak. The first human H5N1 avian flu outbreak was documented in 1997 in Hong Kong, according to the National Library of Medicine of the US government. In 2020, the strain was first detected in Europe. Since then, it has rapidly spread to several countries, including South America.

The current pandemic, resulting in the deaths of millions of birds in 2022 alone, is attributed to a fatal variant of the H5N1 sub-type, as reported by Nature magazine. In South America alone, over 500,000 seabirds, including penguins, pelicans, and boobies, have perished, as indicated by Down To Earth.