From the Southern Ocean to Australia: Tracking H5N1 Across Species and Ecosystems

Dr Jane Younger¹, Dr Augustin Clessin³, Dr Clive McMahon⁴, Dr Nick Fountain-Jones⁵, Dr Amandine Gamble²

¹Institute for Marine and Antarctic Studies (IMAS), UTAS, ²University of Montpellier, ³Integrated Marine Observing System (IMOS), ⁴Tasmanian School of Medicine, ⁵Cornell University

Biography:

Dr Jane Younger is a Senior Lecturer in Southern Ocean Vertebrate Ecology at the Institute for Marine and Antarctic Studies, University of Tasmania. Her research focuses on disease ecology of Antarctic and sub-Antarctic wildlife, with a particular focus on infectious disease transmission in seabirds and seals. Combining field ecology, molecular methods and genomic sequencing, she studies the emergence and spread of highly pathogenic avian influenza (H5N1) across the Southern Ocean. Her work aims to improve understanding of wildlife pathogen transmission and develop internationally coordinated disease surveillance approaches that support wildlife conservation, ocean monitoring and One Health research.

Abstract:

The spread of highly pathogenic avian influenza (H5N1) across the Southern Ocean illustrates how wildlife infections can cross enormous distances and species boundaries. Since 2023, outbreaks have caused substantial mortality among sub-Antarctic seabirds and marine mammals, while multiple viral introductions have been detected in Antarctica. In June 2026, H5N1 was confirmed in migratory seabirds on mainland Australia.

Drawing on research combining wildlife field observations, viral genome sequencing, serology and animal movement data, this presentation will examine the ecological mechanisms underlying H5N1 spread. These include long-distance seabird movements, scavenging, dense breeding aggregations and interfaces between birds and marine mammals. Findings from the Weddell Sea reveal infection in an ice-dependent seal and illustrate how conventional surveillance can miss infections and exposure in remote wildlife populations.

The outbreak also highlights the limits of reactive, mortality-based surveillance. I will discuss how coordinated One Health monitoring can integrate pathogen detection, serology, genomics, ecological data and standardised reporting to identify introductions, track viral evolution and improve early warning. Lessons from the Southern Ocean are increasingly relevant to Australian biosecurity, occupational exposure prevention and cross-sector infectious disease preparedness.