Dugongs are of immense practical, economic, cultural, and spiritual significance to Torres Strait Islander and Aboriginal people living in the region and remain their most highly valued marine food and cornerstone of their traditional subsistence economy.
Torres Strait Islanders are the local custodians of this species and play a continuing stewardship role in sustaining an estimated population of more than 100,000 dugongs in central and western Torres Strait – the largest aggregation globally. This estimate of population is much higher than previous estimates because of improvements in the correction factors for dugongs that are not available to observers in the deeper waters of Torres Strait. The region has been declared an Important Marine Mammal Area largely because of its globally significant dugong population. Due to their migratory nature, dugong conservation requires a coordinated effort across northern Australia and neighbouring countries.
The region’s dugong population is supported by globally significant seagrass meadows and includes the 13,000km2 Dugong Sanctuary. However, since 2018 there has been significant decline in some seagrass habitat, particularly in Western Torres Strait. Dugongs are vulnerable to climate change due to their total dependence on seagrass – with an adult dugong eating up to 40kg a day.
Dugongs are susceptible to climate-related changes in environmental conditions, the loss and deterioration of seagrass habitats, chemical pollution, and local threats such as incidental catch in fishing gear, boating activities, non-traditional take, and illegal fishing. Torres Strait is not immune to these pressures and although their effects on the region’s dugong population is currently unknown, the outlook is one of some concern.
There has been limited dugong monitoring in the region since 2013. Consequently, the state of dugong needs to be viewed in the context of the system-wide declines occurring in marine health, water quality and regional habitats. There is a critical need to re-instigate periodic aerial surveys to better understand factors influencing dugongs and trends in their abundance, breeding and mortality rates and movements.