On Jan. 22, 2024, the University of California, Davis announced the first reported outbreak of high pathogenicity H5N1 avian influenza (HPAI) in elephant seals had been identified by researchers in Argentina. The first reported outbreak of high pathogenicity H5N1 avian influenza (HPAI) in elephant seals was identified by researchers in Argentina.

The mortality rate reached at least 96% by early November 2023, in the surveyed areas at Peninsula Valdes (PV) in Argentina. The outbreak has also caused the death of thousands of South American sea lions and fewer fur seals along the Argentine Patagonia coastline, and now extends into Uruguay and southern Brazil.