The Cause of Mass Deaths of Antarctic Seals and Sea Lions Revealed: "The Most Fearful Thing Is Mutation"

Research Team "Concerns Over Adaptive Mutations in Mammals"
Polar Bears and Sea Lions Also Die After Infection

It has been confirmed for the first time that the mass deaths of mammals such as seals and sea lions in Antarctica were caused by the highly pathogenic avian influenza (H5N1) virus.

The British Guardian reported on the 10th (local time) that a research team from the UK Animal and Plant Health Agency (APHA) recently confirmed H5N1 infections in elephant seals and sea lions inhabiting South Georgia Island, a British Overseas Territory in the South Atlantic.

Elephant Seal at Sea
Photo by Yonhap News

H5N1 is known as a highly contagious avian influenza. The outbreak began in 2021, and by 2022, thousands of infection cases were reported among wild birds and poultry farms in North America. In 2023, approximately 500,000 seabirds in South American regions such as Chile and Peru were infected with H5N1, resulting in mass die-offs.

On South Georgia Island, seals suffered mass deaths, and many sea lions showed symptoms of avian influenza. APHA has been investigating the infection status of elephant seals and sea lions.

Scientist Marco Palchieri witnessed about 20 dead elephant seals and sea lions exhibiting avian influenza symptoms such as coughing, sneezing, and nasal discharge during the investigation. He explained that the number of dead individuals on South Georgia Island was about 100, with elephant seals being the majority.

At that time, infection in brown skuas was confirmed, but elephant seals and sea lions were classified as suspected infection cases, and investigations have been ongoing.

The APHA Influenza and Avian Virology team collected samples that tested positive for avian influenza on South Georgia Island.

He said, "Scientist Marco Palchieri, who participated in the investigation, saw about 20 dead elephant seals on site," adding, "Other sea lions also showed respiratory symptoms of avian influenza such as coughing, sneezing, and nasal discharge."

He continued, "The most concerning thing is that (the avian influenza virus) could cause adaptive mutations in mammals," and added, "Although such mutations were not observed in this sample, continuous monitoring is necessary."

Adaptive mutations can enable the avian influenza virus to infect humans as well.

(This photo is not directly related to the article.) [Photo source=Pixabay]

Earlier last month, a polar bear infected with avian influenza was confirmed dead in Alaska. It is also estimated that about 20,000 sea lions in Peru and Chile died from avian influenza.

Since polar bears are listed on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, there are calls to urgently prevent avian influenza infections.

APHA virologist Ashley Banyard evaluated that while the deaths of seals and birds in Antarctica are concerning, the fact that the virus has not yet spread to other species is positive news.