The future of the southern elephant seals in Peninsula Valdés, Argentine Patagonia, is going through a critical moment. According to a recent study published in Marine Mammal Science, the population could take up to a century to recover from the devastating outbreak of avian flu H5N1 that hit the region in 2023. The epidemic caused high mortality among the pups, and also affected an uncertain number of reproductive adults.
The research, conducted by specialists from WCS Argentina, CONICET, and the University of California Davis, analyzed different scenarios of population recovery. If the virus had only impacted the pups—where mortality is naturally high—the population could have recovered to 2022 levels (18,000 reproductive females) between 2029 and 2051. But if there was also a significant loss of adults, the estimated recovery date would extend to 2091.
The situation becomes even bleaker in cases where the disease affected reproductive females and disrupted the social structures of the group due to the death of adult males, reducing reproductive opportunities. In the worst-case scenarios, where the virus recurs or affects susceptible individuals recurrently, the population would only reach similar numbers to those of 2022 by the mid-22nd century.
The work was based on decades of monitoring and animal health data, allowing for a precise impact modeling. The first evidence of these predictions came with the 2024 breeding season, which showed an alarming figure: the number of reproductive females in the most densely populated areas dropped by 67%, from 6,938 in 2022 to just 2,256 this year. This sharp decline supports the high adult mortality scenarios forecasted by the researchers.
## An Epidemic That Worries Experts
“In just a few weeks, the epidemic reversed half a century of sustained recovery,” warned Dr. Marcela Uhart, Director of the Latin America Program at the University of California Davis and co-author of the study. “Avian flu made it clear the enormous impact that infectious diseases can have on wildlife. And these effects could worsen under current and future climate change conditions.”
Dr. Claudio Campagna, senior advisor at WCS Argentina, added another warning: “Only resilient populations will survive threats like this. To achieve this, it is necessary to reduce other sources of human-induced mortality such as intensive fishing, pollution, or agricultural expansion. But climate change and ocean acidification are out of control. In this context, an epidemic can be the path to extinction.”
WCS Argentina emphasizes the importance of continuing with the periodic monitoring of this species to detect changes in their health status in time and avoid further losses. They also call for protecting breeding areas, especially during the critical months from August to November, and propose measures such as zoning human activities—such as sport fishing or vehicle traffic—that cause disturbances during the breeding period.
“Península Valdés harbored one of the healthiest populations of southern elephant seals, protagonists of a unique ecosystem and unparalleled natural spectacles. Today, after the epidemic, we need more than ever the commitment of the scientific community, authorities, and donors to conserve this and other species that reflect the health of our marine and coastal ecosystems,” concluded Valeria Falabella, Director of Coastal-Marine Conservation at WCS Argentina.
## How Does Avian Flu Affect Different Species?
Avian flu in animals, caused by the avian influenza virus, can have serious consequences ranging from loss of egg production and sudden death in birds to the possibility of transmission to other species, including mammals and humans. In poultry, it can cause severe diseases and high mortality, with a rate of 90% to 100% in chickens. It can also affect wildlife, causing outbreaks and deaths in various species.
### Consequences in Birds
– **In Poultry:** Loss of egg production, sudden death, respiratory difficulties, eye inflammation, nasal secretions, and other symptoms.
– **In Wild Birds:** Outbreaks of death, especially affecting aquatic and coastal species.
### Disease Forms
– **Highly Pathogenic Avian Influenza (HPAI):** Causes severe diseases and high mortality in infected birds, including chickens and turkeys.
– **Low Pathogenicity (LPAI):** Can cause mild or imperceptible symptoms, such as reduced food intake, respiratory signs, or decreased egg laying.
### Consequences in Other Animals and Humans
– **Mammals:** Avian flu can affect mammals, causing symptoms ranging from mild to severe, including death. Recently, it was detected in dairy cows.
– **Humans:** Although direct transmission from animals to humans is less likely, it is possible. In humans, the infection can cause symptoms ranging from mild upper respiratory tract symptoms to severe pneumonia, acute respiratory distress syndrome, shock, and even death.
### Economic Impact
Avian flu outbreaks can have devastating consequences for the poultry industry, the health of wild birds, producers’ livelihoods, and international trade.
In summary, avian flu can have a significant impact on the health of birds, both poultry and wild, and on other animals, including mammals and humans. Virus transmission can cause outbreaks, severe diseases, and deaths, with important economic and social consequences.
Source: WCS Argentina.
