Seven elephant seal pups at California's Año Nuevo State Park have contracted bird flu, marking the first confirmed marine mammal outbreak in the state. Officials have suspended all seal-watching tours for the remainder of breeding season as a precautionary measure.
California wildlife officials have shut down popular elephant seal viewing tours after confirming that seven seal pups have contracted avian flu at Año Nuevo State Park. Additional animals are displaying symptoms of the illness, researchers announced Wednesday.
Scientists from UC Santa Cruz and UC Davis confirmed this marks the first documented case of the bird flu virus affecting marine mammals in California waters.
The global avian flu pandemic that started in 2020 has killed millions of domestic birds and infected wildlife across the globe. Marine mammals like seals and sea lions have proven especially susceptible to the disease. Recent outbreaks have claimed thousands of sea lions in Chile and Peru, thousands of elephant seals in Argentina, and hundreds of seals along New England’s coast.
While health officials consider the virus low-risk for humans, they’re urging the public to stay away from the seals and keep pets at a safe distance.
Each winter, thousands of massive elephant seals migrate to Año Nuevo State Park, located roughly 90 minutes south of San Francisco, for their breeding season activities including fighting, mating and birthing. This natural phenomenon attracts countless tourists and nature enthusiasts who come to observe Earth’s largest seal species, either from designated public areas or through guided docent-led excursions into the breeding colonies.
The park’s viewing areas are now closed and all tours have been suspended “out of an abundance of caution,” according to Jordan Burgess, deputy district superintendent for California’s Department of Parks and Recreation. Officials believe this action will help prevent potential disease transmission that could occur from human foot traffic through elephant seal habitats, she explained.
“We’re definitely not panicking about human exposure at this point,” Burgess stated, emphasizing that the priority is protecting both seal populations and public health.
Christine Johnson, who heads UC Davis’ Institute for Pandemic Insights at the Weill School of Veterinary Medicine, said researchers detected the outbreak rapidly due to heightened surveillance efforts in recent years. After observing sick and deceased animals on February 19th and 20th, scientists gathered samples for analysis at the California Animal Health and Food Safety Laboratory System. Laboratory results confirmed the presence of HPAI H5N1 virus in the specimens.
Approximately 30 additional animal samples are awaiting test results, Johnson noted.
University scientists are collaborating with state and federal wildlife agencies along with The West Coast Marine Mammal Stranding Network to continue monitoring the affected animals.