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For Immediate Release: Wednesday, February 25, 2026
First Cases of Highly Pathogenic Avian Influenza in Northern Elephant Seals Confirmed in California
Cases at Año Nuevo State Park Mark State’s First Detectionof the Disease in a Marine Mammal
For six decades, researchers at UC Santa Cruz have been closely monitoring the colony, providing a unique opportunity to investigate the outbreak in individually identifiable seals and understand the potential near and long-term impacts to population health.
UC Davis scientists have been testing samples from marine birds and mammals at the park and other regions along the coast since 2024. The NSF Center for Pandemic Insights at UC Davis and UC Santa Cruz have been working together to increase surveillance at this site over the past two months in anticipation of a possible outbreak in seals.
The scientific team is now working closely with NOAA Fisheries, the California Department of Fish and Wildlife and the West Coast Marine Mammal Stranding Network to continue to monitor marine mammals along the coast.
“We are cautiously optimistic, as most of the adult females had already departed the beach for their routine migrations before the outbreak began, and most seals on the colony seem healthy,” Beltran said.
People and pets should keep distance
While risk of infection to the general public is low, HPAI can spread between animals and people. Do not touch live or dead seals or allow pets to approach them. This helps protect people and pets and also gives sick animals space.
If you encounter a sick, injured or dead marine mammal in California, Oregon or Washington, call the NOAA Fisheries West Coast Region Stranding Hotline: (866) 767-6114. Do not attempt to move sick wild animals, as this can spread disease and cause stress or harm to the animal.
Looking back and ahead
The H5N1 virus was discovered in 1996 in Southeast China on a domestic goose farm. It was transmitted within the poultry industry for several years, during which it spilled over into wild birds and humans and then spread to Europe, the Middle East, Africa and later to North America, South America and, in early 2024, to Antarctica.
The current outbreak of HPAI in North America was first detected in early winter 2021 in Newfoundland and Labrador, Canada. It has now been confirmed in nearly all U.S. states and Canadian provinces, in commercial poultry, backyard flocks, many species of wild birds, and several species of mammals, including humans.
Two previous HPAI outbreaks in U.S. marine mammals occurred in Maine in 2022 and Washington in 2023. These events were caused by direct spillover of virus from infected birds to seals.
Sustained wildlife surveillance and monitoring is a critical but ongoing challenge for preventing and detecting outbreaks globally. The NSF Center for Pandemic Insights at UC Davis, with collaborators at 12 other institutions, including The Marine Mammal Center and UC Santa Cruz, has been working to develop innovative technologies and methodologies – from chemical sensors to drones – to be able to scale up HPAI surveillance, especially in populations that are less monitored and often harder to access.
The team will generate weekly updates and continue to closely monitor and test samples collected from sick animals, conduct drone surveys, and ensure systematic observations.
More information about this outbreak, including future updates, will be available at the Institute for Pandemic Insights website.
https://www.parks.ca.gov/NewsRelease/1485
First Cases of Highly Pathogenic Avian Influenza in Northern Elephant Seals Confirmed in California
Cases at Año Nuevo State Park Mark State’s First Detectionof the Disease in a Marine Mammal
For six decades, researchers at UC Santa Cruz have been closely monitoring the colony, providing a unique opportunity to investigate the outbreak in individually identifiable seals and understand the potential near and long-term impacts to population health.
UC Davis scientists have been testing samples from marine birds and mammals at the park and other regions along the coast since 2024. The NSF Center for Pandemic Insights at UC Davis and UC Santa Cruz have been working together to increase surveillance at this site over the past two months in anticipation of a possible outbreak in seals.
The scientific team is now working closely with NOAA Fisheries, the California Department of Fish and Wildlife and the West Coast Marine Mammal Stranding Network to continue to monitor marine mammals along the coast.
“We are cautiously optimistic, as most of the adult females had already departed the beach for their routine migrations before the outbreak began, and most seals on the colony seem healthy,” Beltran said.
People and pets should keep distance
While risk of infection to the general public is low, HPAI can spread between animals and people. Do not touch live or dead seals or allow pets to approach them. This helps protect people and pets and also gives sick animals space.
If you encounter a sick, injured or dead marine mammal in California, Oregon or Washington, call the NOAA Fisheries West Coast Region Stranding Hotline: (866) 767-6114. Do not attempt to move sick wild animals, as this can spread disease and cause stress or harm to the animal.
Looking back and ahead
The H5N1 virus was discovered in 1996 in Southeast China on a domestic goose farm. It was transmitted within the poultry industry for several years, during which it spilled over into wild birds and humans and then spread to Europe, the Middle East, Africa and later to North America, South America and, in early 2024, to Antarctica.
The current outbreak of HPAI in North America was first detected in early winter 2021 in Newfoundland and Labrador, Canada. It has now been confirmed in nearly all U.S. states and Canadian provinces, in commercial poultry, backyard flocks, many species of wild birds, and several species of mammals, including humans.
Two previous HPAI outbreaks in U.S. marine mammals occurred in Maine in 2022 and Washington in 2023. These events were caused by direct spillover of virus from infected birds to seals.
Sustained wildlife surveillance and monitoring is a critical but ongoing challenge for preventing and detecting outbreaks globally. The NSF Center for Pandemic Insights at UC Davis, with collaborators at 12 other institutions, including The Marine Mammal Center and UC Santa Cruz, has been working to develop innovative technologies and methodologies – from chemical sensors to drones – to be able to scale up HPAI surveillance, especially in populations that are less monitored and often harder to access.
The team will generate weekly updates and continue to closely monitor and test samples collected from sick animals, conduct drone surveys, and ensure systematic observations.
More information about this outbreak, including future updates, will be available at the Institute for Pandemic Insights website.
https://www.parks.ca.gov/NewsRelease/1485
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