Dugong Population Genomics in Australia

Australia supports the world’s largest remaining dugong (Dugong dugon) population, yet continental-scale connectivity and demographic history remain poorly resolved. Here, we present the first continent-wide population genomic assessment of dugongs using whole-genome sequencing from 210 individuals. We analysed samples collected across the entire Australian range to investigate population structure, inbreeding, and historical demography. We identified three distinct genetic populations, likely shaped by historical sea-level fluctuations and changes in seagrass habitat availability. Demographic reconstructions indicate that dugongs were restricted to small refugia during the Last Glacial Maximum (20,000 years ago), followed by post-glacial population expansion. Genome-wide patterns of diversity suggest that Australian dugong populations remain relatively healthy overall, although elevated runs of homozygosity indicate increased inbreeding at the edges of their range. Admixture analyses further highlight varying levels of connectivity among regions, reflecting both historical isolation and contemporary gene flow. This study offers important insights into how past environmental change has shaped present-day dugong populations. These findings redefine dugong management units at a continental scale, providing a strong evidence base to inform spatial management and the protection of a seagrass-dependent species vulnerable to accelerating coastal change and anthropogenic pressures.

N/A

Australian Marine Sciences Association 2026 Conference

N/A

N/A

N/A

N/A

2