MELBOURNE, June 24 (Xinhua) -- Experts warn H5N1 detections on the Australian mainland could threaten wildlife and accelerate biodiversity loss, after a third mainland case was confirmed on Wednesday.
The highly pathogenic avian influenza virus has now been detected in the state of South Australia following earlier cases in the state of Western Australia, with three seabirds confirmed dead. While the outbreak remains limited, broader spread to other wildlife or livestock is likely, said Professor Euan Ritchie at Australia's Deakin University.
Ritchie cautioned that the virus poses a particular threat to Australia's endemic species, many of which have small, declining or geographically restricted populations. Writing in The Conversation, he said a single mass mortality event could be enough to trigger irreversible declines.
Globally, H5N1 has killed millions of birds and increasingly infected mammals, including through scavenging of infected carcasses. Ritchie warned similar transmission pathways could expose Australia's carnivorous marsupials such as endangered Tasmanian devils and quolls.
"Kangaroos, wallabies, possums and bandicoots can also scavenge and eat meat, meaning they could come in contact with H5N1," he wrote, warning the H5N1 strain could also prove deadly to Australian sea lion and black swan populations.
Scientists said last week that H5N1 killed an estimated 13,000 southern elephant seal pups on Heard Island, marking the first detection of the virus in an Australian external territory. It has also been detected in several other species, including penguins, fur seals and seabirds, on the remote Heard and McDonald Islands.
Ritchie said there are also concerns about ecosystem-wide impacts beyond individual species. An H5N1 outbreak in predator species could drive surges in prey populations, while large die-offs of waterbirds risk worsening water quality and triggering widespread fish kills.
The Australian government had allocated 113 million Australian dollars (about 77.87 million U.S. dollars) to bolster H5N1 response, prior to the detection of its first mainland case. Experts are urging vigilance, including reporting sick or dead animals and avoiding contact with native wildlife. ■