Bird Flu Outbreak Hits California Elephant Seals, Prompting Park Closures

A concerning outbreak of avian influenza (bird flu) has been detected in elephant seal pups at Año Nuevo State Park in California, leading to the cancellation of popular seal-watching tours for the remainder of the breeding season. This marks the first confirmed outbreak of the virus among marine mammals in the state, raising concerns among wildlife officials.

First Detection in California Marine Mammals

Researchers from the University of California, Santa Cruz, and the University of California, Davis, confirmed that seven elephant seal pups have tested positive for the H5N1 avian flu virus. Several additional pups are exhibiting signs of illness, including tremors and seizure-like activity CBS News. The findings were confirmed Tuesday evening by the U.S. Department of Agriculture’s National Veterinary Services Laboratory.

Global Spread and Impact on Marine Life

The current global bird flu outbreak, which began in 2020, has resulted in the deaths of millions of domesticated birds and has spread to wildlife populations worldwide. Seals and sea lions have proven particularly vulnerable. Similar outbreaks have previously impacted marine mammal populations in other regions, including the deaths of thousands of sea lions in Chile and Peru, thousands of elephant seals in Argentina, and hundreds of seals in Fresh England ABC News.

Limited Risk to Humans, Precautions Advised

While the virus is currently considered a low risk to humans, officials are advising the public to avoid approaching seals and to maintain pets away from these animals ABC News.

Año Nuevo State Park Closures

Año Nuevo State Park, located approximately 90 minutes south of San Francisco, is a significant breeding ground for elephant seals. Thousands of these animals gather there each winter to mate and give birth, attracting tourists and wildlife enthusiasts. To prevent further spread of the virus, park officials have closed the viewing area and canceled all guided tours “out of an abundance of caution,” according to Jordan Burgess, the deputy district superintendent of the California Department of Parks and Recreation ABC News.

Rapid Detection and Ongoing Monitoring

Professor Christine Johnson, director of the UC Davis Institute for Pandemic Insights, emphasized the speed of the outbreak’s detection, attributing it to coordinated surveillance efforts CBS News. Researchers have been actively screening seabirds and elephant seals at Año Nuevo State Park and other coastal areas.

As of February 26, 2026, test results are still pending on samples from approximately 30 additional animals ABC7 News. Researchers are collaborating with state and federal wildlife managers and The West Coast Marine Mammal Stranding Network to monitor the situation closely.