Avian flu has reached the Antarctic, raising concerns for isolated populations of penguins and seals that have never been exposed to the deadly H5N1 virus before. The full impact of the virus’s arrival is not yet known, but scientists are raising concerns about possible “catastrophic breeding failure” of the region’s fragile wildlife populations.

The virus was found in populations of a scavenging bird called brown skua on Bird Island, which is part of the British overseas territory of South Georgia and the South Sandwich Islands. These migratory birds probably brought it with them from South America where bird flu is widespread and has already killed an estimated 500,000 seabirds and 20,000 sea lions in Chile and Peru alone.