A marked decline in the southern elephant seal population
A study published in Communications Biology reports a marked decline in the southern elephant seal (Mirounga leonina) population at South Georgia (an island in the South Atlantic Ocean) following the emergence of highly pathogenic avian influenza viruses in 2023. The researchers documented a 47% reduction in breeding females at the island’s major colonies between 2022 and 2024, coinciding with the arrival of the virus.
The scale of this decline exceeds normal year to year variation and indicates a substantial mortality event likely linked to infection. Although the precise mortality rate cannot be determined due to logistical constraints, the pronounced reduction in breeding females suggests significant population-level impacts that may reflect direct mortality, altered reproductive behaviour or movement to alternative sites.
The long term implications are considerable. Reduced reproductive output and diminished population stability are expected if current trends continue, and recovery to pre outbreak levels may take several decades.
