An international team of scientists suspects that thousands of Adelie penguins, which inhabit the coasts of Antarctica, died as a result of an outbreak of bird flu, which leads us to believe that the virus could threaten the conservation of this and other species on the frozen continent..
“This is the first time that wildlife in these regions has been threatened by a large-scale outbreak of the disease.”Meagan Dewar, who led the scientific expedition, told EFE on Tuesday, explaining that still “It is difficult to predict how things will evolve and how the virus will behave in the Antarctic environment”.
Dewar, an expert in biological sciences at Federation University Australia, and her colleagues found 532 carcasses of Adelie penguins (Pygoscelis adeliae) during the southern summer on the Antarctic island of Heroina, in the Weddell Sea, which are believed to have died from HPAIV H5. , a subtype of the avian influenza pathogen.
The alarming thing is that the estimate of mortality throughout the island “is, in reality, in the thousands only for the Adélie penguins” adults and chicks, said the expert in biological sciences, without ruling out that it could have affected other species.
“Unusual” mortality
During the expedition, Dewar's team observed that this was an “unusual mortality” of Adélie penguins given that the adult specimens were in good body condition and because the situation was different from the mortality rate that had been recorded in the season. former.
Although the molecular tests carried out by this team have been negative for avian flu, the researchers have subjected their samples to other laboratory analyzes to confirm the causes of these deaths in a few months.
In parallel, this team of scientists – from Argentina, Germany, Australia, Spain and Holland – is also trying to determine if the virus comes from South America or the sub-Antarctic islands, its impact in the future, as well as the risk it poses. for other species on the frozen continent.
From the corral to Antarctica
The HPAIV H5 avian flu, which initially evolved in poultry, has already caused a significant mortality of wild birds and mammals on an almost global scale since 2020.
At the beginning of the year, the Severo Ochoa Molecular Biology Center of the Higher Council for Scientific Research (CSIC) of Spain confirmed the arrival of the H5 subtype of avian flu to Antarctica, which raises fears of rapid expansion, especially among penguins that reproduce and they breed in colonies.
According to the expert from the Australian university, this situation would be aggravated by the pressure of the climate crisis, since it is believed that “the movement of viruses to the region could increase, and the added pressures of climate change can make species more vulnerable to the virus and its effects.”
“It is difficult to predict how the virus will affect penguins, but it has the potential to cause mass mortality events, which could cause significant losses; However, whether these losses are observed at the colony level or in the entire region is difficult to predict”Dewar stressed.
This discovery of the “unusual” death of Adélie penguins occurred after his team detected on December 31 an “unusual mortality” of skua birds (Stercorariidae), also known as skuas.
An international team of researchers – led by Chilean scientists – reported in 2014 in the magazine MBio that they identified, for the first time, the avian flu virus in a group of Antarctic penguins.
According to Dewar, for the moment, the results have been negative for HPAIV H5 in Heroin and the surrounding Beagle Island. “Therefore these are unusual cases of mortality. The report from Chile indicates that H5N1 has been detected.