A deadly strain of bird flu that has already killed millions of seabirds across the world is likely to land on Antarctic shores this summer, threatening already struggling penguin colonies and marine mammals.
The highly pathogenic avian influenza, known as H5N1, first started to cause mass mortality outbreaks in seabirds in the northern hemisphere in late 2021.
By October last year, it had reached South America.
Chair of the Antarctic Wildlife Health Network Dr Meagan Dewar said in South America there was a “rapid increase in how quickly the virus was spreading through wildlife”.
“Pretty much it did the entire coast from around Peru to the bottom of Chile in about three to four months, it moved that quickly through,” she said.
“It also then spilled over into marine mammals.
“So far approximately we’ve had over 20,000 South American sea lions dying in Peru and Chile and now we have significant cases happening in Argentina as well.”
H5N1 has now spread to almost every continent. There are two exceptions — Australia and Antarctica.
But the migratory birds in South America will soon head further south, leading experts to believe the virus will reach the sub-Antarctic islands and Antarctica itself this summer.
Long-lived seabird populations will take ‘a long time’ to recover
Australian Antarctic Division (AAD) seabird ecologist Dr Louise Emmerson is worried about what that means for the already vulnerable seabirds.
“The seabirds are the mostly highly threatened taxa [group] within the bird group and they are already experiencing pressures from climate change, from fishing, from human disturbance and habitat loss,” Dr Emmerson said.
“So having this virus on top of all those things could be even more devastating for the seabirds.”Most of them are a long-lived species, so it’s going to take a long time for these populations to recover, assuming that some local populations may not have all the birds wiped out.”
Dr Emmerson said the seabird team at AAD were currently relying on station leaders to send through videos to monitor for signs of the virus, but they would soon have a team on the ground.
“Some of the signs that we look for with the birds will be trembling and shaking and dead animals,” she said.
“Just taking a look with expert eyes to see, ‘Is it abnormal?’, will be a key priority for the seabirds team when they get on the ground.”
‘We can’t stop it’
Experts believe the virus’s arrival and impact on the icy continent will be “unprecedented” — not only will seabirds be under threat, but the seals and sea lions that live amongst them.
The first cases are expected to pop up in the Antarctic Peninsula — the area in the west of the continent, closest to Argentina and Chile.
