Avian Flu Spreads in Bay Area Parks
A deadly avian flu outbreak at Año Nuevo State Park is spreading to nearby beaches and other species, prompting concern among pet owners and wildlife advocates. Families visiting area parks should keep dogs on leash and avoid contact with sick or dead birds. Keep pets’ vaccinations up to date and practice good hygiene after outdoor play.
The outbreak, initially detected in elephant seals at Año Nuevo State Park in February, has now spread to sea lions and a sea otter. Wildlife experts confirmed the virus is expanding to nearby public beaches. The HPAI H5N1 virus, identified as the A3 genotype, is responsible. The Año Nuevo State Park outbreak led to the cancellation of all seal tours for the season, impacting thousands of visitors. Researchers are closely monitoring the situation, with approximately two dead and two newly infected animals discovered daily. As of mid-March, scientists estimate around 47 seals on the mainland have died since the outbreak began. This particular strain, A3 genotype, first emerged in Eurasia in 2022 and caused a mass die-off of seals in Russia in 2023. It's the first time this strain has been detected on the Pacific coast of the U.S. The virus has also been confirmed in seabirds like gulls and cormorants. The Marine Mammal Center has temporarily halted rescue operations for elephant seals as a safety precaution. Experts urge the public to avoid contact with stranded marine mammals and birds, and to keep pets leashed. This is to minimize the risk of transmission, though the risk to the general public remains low. A recent study indicates that a local peregrine falcon population has been declining for years due to the same avian flu strain. Bay Area peregrine falcon numbers began plummeting after a massive, global outbreak of avian flu in 2020, with only about a third of nesting sites still in use as of 2025.
