A catastrophic outbreak of bird flu has decimated the southern elephant seal population on the remote island of South Georgia, with a shocking new study revealing nearly half the breeding females have perished.
Stark Numbers Reveal Ecological Disaster
Research published in the journal Communications Biology estimates that approximately 53,000 female elephant seals have died since the H5N1 avian influenza virus reached the island in 2023. The population has plummeted by 47%, a figure that stunned researchers.
"It was quite a stark number," said lead author Connor Bamford from the British Antarctic Survey in Cambridge. "I didn't anticipate it to be this high."
The island in the South Atlantic Ocean hosts the world's largest southern elephant seal population, representing 54% of the global breeding population. Researchers used aerial imagery from three beaches to compare breeding numbers between 2022 and 2024, revealing the devastating scale of loss.
Hidden Death Toll and Breeding Crisis
The true death toll is likely even higher than recorded, as many sick animals probably returned to the sea to cool down, meaning their bodies were never counted. The impact was so severe that in 2024, tourists reported that explorer Ernest Shackleton's grave had become inaccessible due to "dead seals blocking the way."
There was particularly high mortality among pups, and researchers suspect the direct losses were exacerbated by females becoming physically stressed and abandoning their young. Since females take three to eight years to start breeding, this represents a long-term threat to population recovery.
"We were aware there was a high level of mortality – way above normal levels – but it wasn't until we got this before-and-after comparison that we could see how extensive it was," Bamford explained.
Ongoing Threat and Global Implications
The crisis is far from over, with current observations suggesting the virus continues to circulate in the population. "One of my colleagues is down there on a ship at the moment, and this year the count is lower than it was last year. That suggests the virus is circulating in the population," said Bamford. "I wouldn't say it's over at all."
The highly pathogenic H5N1 strain initially detected in Europe has been spreading across bird and mammal species worldwide, reaching South Georgia in 2023. Its full impact took time to calculate due to the region's extreme remoteness.
Professor Ed Hutchinson, a virologist at the University of Glasgow not involved in the study, described the findings as "heartbreaking" and expressed concern about the virus's potential impact on other Antarctic and sub-Antarctic species.
Researchers warn that "the apparent loss of nearly half the breeding female population has serious implications for the future stability of the population" and emphasize the "urgent need for continued, intensive monitoring."
