Hundreds of seal pups have been discovered dead on Heard Island in the sub-Antarctic, with Australian scientists investigating whether a destructive bird flu that has swept the globe is responsible.
The virulent H5N1 strain has caused millions of deaths among wild birds and mammals since 2021, also affecting poultry and dairy farms and infecting some farmworkers.
While “not a confirmed detection” at this stage, Australia’s agriculture department is sending samples from the dead seals for urgent testing.
The ministry added that symptoms consistent with H5 bird flu on Heard Island were “not unexpected,” as the virus has already been found on the nearby French Kerguelen and Crozet islands.
Off the migration routes of big birds such as geese that spread infection, Australia is the only continent free of the highly contagious virus. But further spread through Antarctica could eventually raise the risk of infection from the south.
Heard Island would be the farthest the flu has reached in the Antarctic since arriving from South America in 2023.
Formed by a 2,745-meter (9,006-foot) volcano that rears up from the sea more than 4,000 km (2,486 miles) southwest of Perth and 1,700 km (1,060 miles) north of Antarctica, it is a breeding ground for large populations of penguins, seals and seabirds.
Scientists of Australia’s Antarctic Division who spent 10 days there found healthy animals until late in their trip when they encountered hundreds of dead elephant seal pups, said Julie McInnes, one of its ecologists.
“It was a significant proportion of the pups in that section (of beach),” said McInnes, who was on the trip.
It was unclear whether the virus will spread to other areas or species on the island and researchers will visit again around year-end, she added.
The agriculture ministry said the confirmation of bird flu would not substantially increase the risk of its spread to Australia.
Australia has been bracing for the arrival of H5N1 bird flu, tightening biosecurity at farms, testing shore birds for disease, vaccinating vulnerable species and war-gaming response plans.