Dugongs (Dugong dugon) are obligate seagrass grazers whose specialised diet and shallow-water habitat make them highly sensitive to bottom-up disturbances. Shark Bay, Western Australia, supports one of the world’s largest dugong populations but experienced catastrophic loss of its dominant seagrass meadows during the 2011 marine heatwave. Using satellite tracking data collected before (2000–2002) and after the heatwave (2023–2024), we estimated individual home ranges and utilisation distributions to examine how habitat degradation influenced spatial behaviour.
Population-level analyses revealed that dugongs utilise the full extent of the Shark Bay ecosystem, although post-heatwave movement patterns seemed to focus towards seagrass meadows. To investigate drivers of space used, we developed species distribution models integrating sea surface temperature, salinity, bathymetry, ocean currents, chlorophyll-a, and wind. The results highlight the resilience and adaptive movement of dugongs in a highly dynamic ecosystem and provide new insights into how large-scale habitat loss and environmental variability shape the spatial ecology of marine megaherbivores. Understanding these patterns is critical for predicting responses to future climate-driven disturbances and guiding conservation in Shark Bay.