About 60 marine mammals are being tested for highly pathogenic avian influenza after a recent outbreak at Año Nuevo State Park in Northern California. At least 12 northern elephant seal pups have tested positive.
These are the first cases of avian flu detected in marine mammals in California. A spokesperson with the University of California, Davis, which is responding to the outbreak alongside the University of California, Santa Cruz, and federal and state agencies, said it is unclear at this time how the elephant seals at Año Nuevo may have been exposed to the virus.
Other H5N1 outbreaks have decimated Argentina's remote population of southern elephant seals, and Hawaiʻi scientists worry that the virus could have a "catastrophic" impact on Hawaiʻi's endangered monk seals.
No Hawaiian monk seals are known to have contracted the virus. But the presence of the virus in California marine mammal populations "raises the overall sense of risk" for Hawaiian monk seals, said Dr. Sophie Whoriskey, the associate director of conservation medicine at Ke Kai Ola, the dedicated Hawaiian monk seal hospital in Kona.
Whoriskey and her colleagues are closely monitoring the California outbreak, as well as continuing efforts to vaccinate monk seals against H5N1.
So far, Ke Kai Ola has administered H5N1 vaccines to three monk seal pups in their care. None of the pups has experienced any adverse reactions to the vaccine.
Blood tests from the first monk seal pup to receive the vaccine show that it prompted a strong antibody response, suggesting that the vaccine will offer the pup some protection if it encounters the bird flu virus.
Antibody results for the other two pups will be available in the coming months.
Moving forward, Ke Kai Ola plans to vaccinate all monk seals in good physical condition that receive care at their facility.
While the risk of avian flu is low at this time, Whoriskey cautions that the virus can be transmitted from animals to humans.
If you observe a monk seal that appears to be sick, keep your distance and call Ke Kai Ola's hotline: 808-987-0765 on Hawaiʻi Island or 1-888-256-9840 statewide.
