Avian Influenza suspected of reaching Australia’s sub-Antarctic Heard Island

 
“Heard Island and nearby McDonald Island are unoccupied by humans and remain one of the world's least anthropogenically disturbed areas”, photograph with a passing Wandering Albatross by Pete Harmsen, CSIRO

Highly pathogenic avian influenza (HPAI) has been, seemingly inexorably, spreading around the islands of the Southern Ocean. First recorded in the South Atlantic sub-Antarctic, it was more recently confirmed on the southern Indian Ocean’s Marion Island (South Africa) and France’s Possession, Crozets and Kerguelen Islands.

Now an ongoing expedition to Heard Island, 400 km south of Kerguelen, the first in quite a few years, has recently reported suspected cases of HPAI among the island’s Southern Elephant Seals Mirounga leonina, after observing  unusual levels of mortality  So far it is not suspected among the island’s penguins and other seabirds.  Samples have been taken for return to the Australian mainland in mid-November to confirm the presence of avian flu by the CSIRO Australian Centre for Disease Preparedness.

“Wildlife ecologists taking samples from deceased animals at Atlas Cove, Heard Island”, photograph by Rowena Hannaford

Dr Julie McInnes, a wildlife ecologist at the Australian Antarctic Division, said initial drone and ground surveys of the island did not indicate any unusual levels of mortality.  But when the scientists made their way to the south-east of the island, dead elephants seals, including pups, were discovered.  "We undertook widespread aerial surveys with concurrent ground counts in the region, and samples were also obtained from a number of deceased animals.  The majority of mortalities were detected in elephant seal pups and in a small number of adults.”

Read more from the Australian Antarctic Program here.

Highly pathogenic avian influenza has not yet been reported from Australia’s Macquarie Island or New Zealand’s sub-Antarctic islands, both to the east of Heard Island.  Just a matter of time?

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 29 October 2025