Avian flu contributes to elephant seal declines 

Not only has the avian flu evolved into a separate virus for elephant seals, but it has also caused declines in populations of the marine mammals on their breeding grounds in South America. Following the initial outbreak of H5N1 in 2023, more than 17,000 elephant seals (Mirounga leonina) have died. That includes about 97% of pups, scientists estimate. Researchers recently published a study in Nature Communications that found the virus mutates to adapt and spread between marine mammal species. “We were totally appalled by the dramatic impact of the epidemic of avian influenza on this population,” said co-author of the study Valeria Falabella, Wildlife Conservation Society Argentina director of coastal and marine conservation. “It is likely that more than half of the reproductive population died due to the virus. It will take decades before the numbers are back to the 2022 population size.” So far, no elephant seals have tested positive this breeding season. 

Read more in Nature Communications.