Over the past three years, a extremely deadly type of avian influenza has whipped all over the world, felling birds in Europe, Africa and Asia earlier than leaping throughout the ocean and setting off the worst chicken flu outbreak in United States historical past.
Final fall, the virus, often known as H5N1, lastly arrived in South America. It raced shortly down the Pacific coast and killed wild birds and marine mammals in staggering numbers. Peru and Chile alone have reported greater than 500,000 useless seabirds and 25,000 useless sea lions, in response to a brand new report, which was printed final week by OFFLU, a worldwide community of flu consultants.
Now, scientists are anxious that the virus will make its option to Antarctica, one among solely two continents — together with Australia — that haven’t but been hit by the pathogen. “The unfavourable affect of this virus on Antarctic wildlife may very well be immense — possible worse than that on South American wildlife,” the report warns.
Greater than 100 million birds breed in Antarctica and on the islands close by, and lots of marine mammals swim within the surrounding waters. A few of these species, together with the distinctive emperor penguin and Antarctic fur seal, crowd collectively in massive colonies. “And that may very well be a recipe for catastrophe,” mentioned Dr. Ralph Vanstreels, a researcher at a Latin American wildlife well being program on the College of California, Davis, and an writer of the brand new report. “We may very well be taking a look at a really excessive dying toll.”
This chicken flu variant, which emerged in 2020, has induced monumental outbreaks on poultry farms, ensuing within the deaths of almost 60 million farmed birds in the USA alone. However in contrast to earlier variations of the virus, it has additionally unfold extensively in wild birds and routinely spilled over into wild mammals.
The virus first appeared in South America in October 2022, spreading from Colombia right down to Chile in simply three months. “As quickly because it began transferring south, it did so very, very quickly,” mentioned Dr. Marcela Uhart, who directs the U.C. Davis Latin American wildlife well being program and is an writer of the OFFLU report.
The casualties are troublesome to tally as a result of many contaminated animals have been most likely by no means detected, scientists mentioned, and never all the useless animals that did flip up have been examined for the virus. However a whole lot of hundreds of useless seabirds, together with boobies, cormorants and gulls, have been reported in South America. The losses accounted for 36 % of Peru’s inhabitants of Peruvian pelicans and 13 % of Chile’s Humboldt penguins, in response to the report.
South American sea lions additionally died by the hundreds, representing 9 % of the inhabitants in Peru and Chile. (Scientists are nonetheless unsure precisely how marine mammals are contracting the virus or whether or not it’s spreading readily amongst them.)
The virus has continued to maneuver south. In June, it turned up in a South American sea lion within the far south of Chile, simply 670 miles from the Antarctic Peninsula. Some birds routinely wander between South America and Antarctica, feeding in each places. Others will make their option to their Antarctic breeding websites as spring arrives within the Southern Hemisphere, probably bringing the virus with them.
Antarctica has by no means had an outbreak of extremely pathogenic chicken flu earlier than and its residents are more likely to have few immune defenses towards the virus. “The populations are utterly naïve,” mentioned Dr. Thijs Kuiken, a veterinary pathologist at Erasmus College Medical Heart within the Netherlands and an writer of the brand new report. “The concern is that the primary time that it goes by, it can actually have a excessive affect by way of charge of mortality.”
Lots of the area’s birds, together with emperor penguins and sooty shearwaters, are already going through different threats, from sources together with local weather change, the fishing trade or different human actions. Some species, just like the southern pintail and the Macquarie shag, are restricted to only a few islands. “So when you have been to get an outbreak in these islands, mainly the entire species collapses,” Dr. Vanstreels mentioned.
Native marine mammals may very well be in danger, too. Though the Antarctic fur seal can vary extensively, 95 % of the inhabitants lives round only one island, making it susceptible to an outbreak.
At this level, the virus is so widespread that it will not be doable to cease it from reaching Antarctica. “In the intervening time, there’s nothing we are able to do to stop it,” Dr. Kuiken mentioned. “So it’s vital within the coming months to be as alert as doable.”
It is going to be essential to observe wild populations to study extra about how the virus is spreading, what species may be most in danger and what conservation actions may be wanted to assist them recuperate, scientists mentioned. “What we’re making an attempt to do is doc this very well, making an attempt to grasp how the virus is transferring to see how we are able to higher defend the species going ahead,” Dr. Uhart mentioned.
