Bird Flu Outbreak Among CA Marine Mammals Remains Small But Concerning

Katherine E Kerlin — March 13, 2026 - 9:36am

Scientists and wildlife specialists continue to sample and monitor marine mammals in California, where the first cases of highly pathogenic avian influenza (HPAI) H5N1 in a California marine mammal were detected and announced last month in San Mateo County.

First Cases of Highly Pathogenic Avian Influenza in Northern Elephant Seals Confirmed in California

Katherine E Kerlin — February 25, 2026 - 10:00am

Note: March 12, 2026: This outbreak is ongoing. For the latest updates and materials, please visit the Institute for Pandemic Insights information page.

Seven weaned elephant seal pups in California’s Año Nuevo State Park tested positive for highly pathogenic avian influenza (HPAI) H5N1, the U.S. Department of Agriculture’s National Veterinary Services Laboratory confirmed Tuesday evening.

Institute for Pandemic Insights Content

Bird Flu Outbreak Among CA Marine Mammals Remains Small But Concerning

First Cases of Highly Pathogenic Avian Influenza in Northern Elephant Seals Confirmed in California