‘Impact could be huge’: Scientists fear bird flu could reach Antarctica

New York. -In the past three years, a highly lethal variant Avian Influenza It swept across the globe, killing birds in Europe, Africa, and Asia, before crossing oceans to unleash the largest disease outbreak in U.S. history.

About a year ago, the virus was called H5N1 It eventually reached South America, where it rampaged along the Pacific coast, killing a staggering number of wild birds and marine mammals. In Chile and Peru alone, more than 500,000 seabirds and 25,000 sea lions have died, according to a new report published last week by the bird flu expert Offlu Network.

now scientists worry The virus has spread to AntarcticaAustralia is one of only two continents not yet hit by the deadly pathogen. “The negative impact of this virus on Antarctic fauna is likely to be substantial, perhaps even greater than the impact on South American wildlife,” the report states.

More than 100 million birds mate in Antarctica and nearby islands, and the surrounding waters are home to countless marine mammals.Some of these species, including characteristics Emperor Penguins and Antarctic Fur Seals

They live in large groups. “This could spell disaster,” said Dr. Ralph van Stries, a researcher at the University of California’s Wildlife Health Program and one of the authors of the new report. “The mortality rate of these animals can be very high.”

The H5N1 bird flu variant emerged in 2020 and has since caused massive outbreaks on poultry farms, killing an estimated 60 million poultry in the US alone. But unlike previous variants, N5H1 is also spreading rapidly among wild birds and mammals.

The virus was first registered in South America in 2022 and spread from Colombia to Chile in just three months. “It’s moving south at full speed,” said Dr. Marcela Uhart, director of the UC Latino Wildlife Health Program and another author of the Offlu report.

The total number of these deaths is difficult to estimate, scientists say, because many infected animals may never be found, and not all animals that die have been tested to see if they died from the virus.But in South America, they have been reported Hundreds of thousands of seabirds die, including cormorants, gannets and gulls. These losses accounted for 36 percent of pelican populations in Peru and 13 percent of Humboldt penguins in Chile, the report said.

Thousands of South American fur seals also died in Peru and Chile, a 9% decline in their numbers. Scientists still aren’t sure exactly how marine mammals become infected with the virus, or whether it spreads easily among marine mammal populations.

The virus continues to spread southward. In June, the virus was found in a dead South American sea lion on the southern tip of Chile, just 1,000 kilometers from the Antarctic Peninsula. Some birds frequently roam between South America and Antarctica, feeding in both places. Others arrive at their breeding grounds in Antarctica when spring begins in the southern hemisphere, potentially bringing the virus with them.

Antarctica has never had an outbreak of highly pathogenic bird flu, most likely because Animal inhabitants have poorer immune defenses against viruses. “People were completely unaware of the virus,” said Dr. Tess Kuiken, a veterinary pathologist at Erasmus University Medical Center in the Netherlands and another author of the new report. “The most worrying thing is that when it comes, it will have a big impact on mortality.”

Many bird species in the area, including emperor penguins and gulls, already face other threats such as climate change, fisheries or other human activities. Some species, such as the southern duck and the Macquarie cormorant, are restricted to a few islands. “So, if there’s an outbreak on these islands, it basically causes the entire species to collapse.” Van Stries warned.

Native marine mammals may also be at risk. Although Antarctic seals are widely distributed on the white continent, 95% of their populations live around a single island, making them highly vulnerable to outbreaks.

By now, the virus has become so widespread that it may not be possible to stop it from reaching Antarctica. “There’s nothing we can do to stop it at the moment,” Kuiken said. “That’s why we have to be extremely vigilant in the coming months.”

The key, scientists say, is to monitor wild populations to better understand how the virus spreads, which species are most at risk, and what conservation actions are needed to help them recover. “We’re trying to document all of this in detail to understand how viruses develop so we can better protect these species in the future,” Uhart said.

Emily Anthes

(Translated by Jaime Allenbeed)

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