Tweet
bump this
-
bump this
-
Avian influenza is a devastating setback for the Patagonian elephant seal population- by Debora Mazzola, WCS Argentina
- April 16, 2025
It may take a century before a southern elephant seal colony, hit by an epidemic, comes back to original numbers, according to a new study published by WCS Argentina, CONICET and the University of California, Davis.
Spanish Translation Here
New York, April 16, 2025-- It may take 100 years for the southern elephant seal colony of Península Valdés in Argentine Patagonia to look like it did in 2022. A study published in Marine Mammal Science has projected population trajectories after the 2023 epidemic of the High Pathogenicity Avian Influenza H5N1 virus, which killed almost all newborn pups and an unknown number of adults.
Had the episode killed only pups, the future population could recover to 2022 levels (18,000 adult females) as soon as 2029, and as late as 2051. This is because natural mortality is always high at the early stages of life for the species. But if the disease had mainly impacted a significant part of the reproductive female population, the expected year of recovery would be 2091.
There are even worse possible scenarios, such as when female mortality is combined with lost reproductive opportunities due to adult male mortality, or when the epidemic repeats and kills seals that are susceptible. In the worst cases, the population would not look like that of 2022 until the mid-22nd century.
The first real-world test of the hypothetical scenarios occurred during the 2024 breeding season. Counts yielded support to scenarios of high adult mortality, with 67% fewer reproductive females at beaches that had typically been the most densely populated of the entire colony (6,938 females in 2022 vs. 2,256 in 2024). Differences could be attributed to mortality, a delay in the arrival of animals, animals that skipped a season, or a redistribution and colonization of new places. Yet, data for the molting season strongly suggest that adult mortality explains the results.
So far, evidence suggests that the viral episode significantly impacted adult individuals, reversing the conservation status of a population previously having no significant threats to stable growth. It demonstrates how in just a few weeks, the future of the population mutated from no conservation concern to quite vulnerable and uncertain. The risk of infectious diseases impacting natural populations could increase with the worsening of climate change.
Said Valeria Falabella, WCS Argentina director of coastal-marine conservation and co-author of the study: "With decades of growth, the southern elephant seal of Península Valdes was a healthy population and a protagonist of amazing natural spectacles. Until the avian flu of 2023 left thousands of dead calves and our eyes in tears. The continuous monitoring carried out by WCS Argentina and CONICET allows us to measure the impact, and now more than ever we will need the support of our donors to continue monitoring this and other sentinel species of the integrity of our coastal and marine ecosystems."
Dr. Marcela Uhart, director of the Latin America program at the University of California, Davis, and co-author of this study, noted that “Avian influenza has starkly demonstrated the devastating impact that infectious diseases can have on wildlife populations. These effects are likely to intensify under current and projected climate change conditions. It is imperative that we significantly strengthen our upstream prevention efforts to mitigate future risks.”
Dr. Claudio Campagna, WCS Argentina senior advisor and also co-author of the study, pointed that "only resilient populations with healthy numbers and ample distribution may survive these threats and remain safe from most of the many causes of mortality associated with human activities, such as high-impact fisheries, large-scale agriculture and mining, and pollution. Yet, the more global warming and ocean acidification are out of control, the worse for biodiversity in general, making epidemics a path toward potential extinctions."
These scenarios are supported by decades of demographic and animal health data gathered by researchers from the Wildlife Conservation Society Argentina (WCS Argentina), the National Research Council of Argentina (CONICET) and the University of California, Davis, supported by the Liz Claiborne and Art Ortenberg Foundation, a key donor for monitoring coastal-marine species in Patagonia.
Media Resources
Media Contact- Mary Dixon, WCS, mdixon@wcs.org
- Debora Mazzola, WCS Argentina, dmazzola@wcs.org
----------------------------------------------------
Translation Google
The law for the protection of elephant seals in Chubut was approved.
By | Views: 328 | abril 24, 2025
In 2023, an avian flu epidemic killed 97% of the southern elephant seal's offspring and a high proportion of breeding adults on the Valdés Peninsula. According to a recent study published in Marine Mammal Science, it will take decades for the Patagonian population of this emblematic species to recover. The new law promoted by provincial representative Sergio Daniel González seeks to contribute to their care, especially on beaches where the animals are exposed to human disturbance.
Elephant seal calf. Credit: Valeria Falabella - WCS Argentina.
April 24, 2025 - On Thursday, April 24, the Chubut Legislature approved the law declaring the protection of the southern elephant seal ( Mirounga leonina ) throughout the province. This is the largest seal in the world and is one of the tourist attractions of Peninsula Valdés, where more than 80% of the only continental breeding colony is concentrated. Until 2022, this population remained healthy; however, during the 2023 breeding season, it was severely affected by the avian flu epidemic, which killed 97% of the pups and an undetermined number of breeding adults, reclassifying its conservation status to "vulnerable." The new law seeks to contribute to its recovery by protecting these animals on the Chubut coasts, especially on beaches where they are exposed to human disturbance.
Southern elephant seals are exceptional animals; adult males are characterized by their prominent trunk and large size; they can weigh up to 3.5 tons and measure up to 5.5 meters in length, while females can reach 3 meters and weigh about 900 kg. They spend most of their time at sea, where they travel thousands of kilometers to feed, diving to depths of up to 2,000 meters in search of fish and squid. Each year, they complete two terrestrial stages: they reproduce in September and October, and they molt between November and March. The species is protected within the Valdés Peninsula ; however, to the south of that protected area, in the area between Punta Ninfas and Bajo de los Huesos, and in the Isla Escondida sector, the elephant seal population is distributed along coastlines where there is no protection whatsoever.
“The periods these animals spend on land are particularly vulnerable because they are completing essential stages of their life cycle, such as nursing their young, during which they undergo prolonged fasting. Vehicle traffic and the proximity of people and pets affect their behavior and can lead to undesirable consequences, such as abandoning the young if the mother feels threatened, or high energy expenditure from having to move,” explains Julieta Campagna, Valdés landscape coordinator for WCS Argentina, an organization that has contributed to elephant seal research and conservation since the 1980s.
In this regard, the approved regulation seeks to define strategies based on scientific evidence and implement monitoring and management actions to protect critical habitats and essential areas for the species from human and environmental impacts. For example, it promotes responsible tourism practices by establishing a 50-meter "no approach" safety zone around specimens when they are found on the coast, outside of protected areas, in order to reduce stress and prevent alterations in their natural behavior. It also provides an awareness program on the importance of preserving the species.
“Chubut's wildlife is a natural spectacle that attracts tourists from all over the world. This law seeks to increase the protection of elephant seals along the entire coast, raise awareness among visitors about the necessary care and the consequences that their proximity can cause, and create a fund to cover conservation efforts,” emphasizes provincial representative Sergio Daniel González.
ATVs ride along the beach where elephant seals rest. Credit: Julieta Campagna - WCS Argentina.
The new law sets a unique precedent for Chubut and strengthens the collaborative efforts of the community, organizations, and government to protect this species. The project was achieved thanks to the collaborative efforts of WCS Argentina, Representative Sergio González and his team, Natalia García, Manager of the Mixed Rawson Tourism Board (EMRaTur), nature photographer Adriana Sanz, Representative Fabián Gandon, Gabriela Bellazzi, President of the Puerto Pirámides City Council, Nadia Bravo, Undersecretary of Conservation and Protected Areas, and Fernando Bersano of the provincial Wildlife and Flora Directorate.
A key law for the recovery of a vulnerable species
According to specialists, it will take decades for the southern elephant seal population of the Valdés Peninsula to recover from the avian flu epidemic it suffered in 2023. In April 2025, a study was published in the scientific journal Marine Mammal Science conducted by WCS Argentina, CONICET and the University of California Davis indicating that it could take three human generations without new impacts to see these animals as healthy and numerous as they were before the epidemic.
Scientific projections are alarming: if the outbreak had affected only the young, the population could recover by 2035. If the epidemic significantly reduced the number of reproductive females, population recovery would take more than 50 years. The worst-case scenario would be a recurrence of the epidemic, which would pose a risk of incalculable proportions to this and many other species, including humans.
In coastal areas not formally protected, the main impact of human presence is related to careless behavior, such as driving all-terrain vehicles on beaches with elephant seals, throwing rocks at them to mobilize them, allowing dogs to approach them, and even reports of extreme behavior such as shooting them with firearms. Furthermore, the presence of waste left by visitors or plastic debris from fishing, such as nets and straps, can cause entanglement of this and other species.
At sites with elephant seals exposed to disturbances during the breeding and nursing stages, calf mortality can be five times higher than at protected beaches. Therefore, the recently passed law is key to defining precautionary and responsible management along the entire coast regarding activities that can be carried out, particularly during the spring, which coincides with the reproductive period of this species on the coast of Chubut.
Map showing the distribution area of the southern elephant seal off the Patagonian coast. Credit: WCS Argentina.
RELATED LINKS:- New publication highlights the impact of avian flu on southern elephant seals
- A drastic drop in the number of elephant seals on the Valdés Peninsula, as a result of the 2023 avian flu.
- We installed signs on Isla Escondida to protect elephant seals during breeding season.
- Extreme mortality of southern elephant seal pups on the Valdés Peninsula
...
 foto Valeria Falabella WCS Argentina IMG_5725_cuadrada.jpg)
Comment
Comment