Understanding dugong population health

Through our regular large-scale aerial surveys, our researchers have a strong understanding of dugong populations across northern Australia – but we don’t understand how healthy these populations are.

Seagrass diebacks, often caused by cyclones and floods, have previously led to dugong starvation and failed calf reproduction. Poor nutrition can delay dugong sexual maturity and reduce their number of calves, significantly slowing population recovery in impacted regions.

While we know that dugong energy use and food intake change with the seasons and reproductive cycles, we do not fully understand how this affects their health. Consistent monitoring is key to linking nutrition, reproduction, and environmental changes and to identifying dugong populations that may be struggling.

Assessing dugong health using drones

Our researchers are pioneering a technique using drone imagery to assess the body condition of dugongs. This approach is non-invasive and affordable, building on the existing use of drones for dugong population counts.

As part of doctoral research by Sarah Landeo, the team aims to:

• Develop and validate different body condition indicators for dugongs based on morphometric measurements from drone-based photogrammetry.

• Describe the population structure – based on body size – and seasonal variation in body condition of the dugong population of Cleveland Bay over one year.

• Compare the structure – based on body size – and body condition of dugongs between tropical and subtropical high-density areas with different environmental conditions, from late autumn through to early spring.

• Investigate regional differences in the body condition of female dugongs and calves in several locations through the species’ geographic range.

These findings will provide crucial context for any changes in overall health of this dugong population in the future to inform management and conservation. Identifying declines in dugong body condition may also reveal habitat losses that are not detected through seagrass monitoring.

Once the method is refined, our team hopes to work with Traditional Owners across eastern Queensland to establish community-led monitoring programs using this method to measure dugong health.

Project details

This project is led by Dr Christophe Cleguer and PhD student Sarah Landeo-Yauri, with Frederik Christiansen, Aarhus University. The project is funded by the National Environmental Science Program and the Ecological Society of Australia – Holsworth Wildlife Research Endowment Grant.