The dugong is a relative of the manatee, commonly known as the sea cow. This nickname comes from the fact that manatees are large, slow moving creatures that spend their days grazing on seagrass, much like how cows graze all day long. Unlike manatees that inhabit bodies of freshwater, dugongs roam the tropical coastal regions of the Indo-West Pacific Oceans. Dugongs and manatees are the only herbivorous marine mammals, and they are both listed as vulnerable species by the World Wildlife Fund. Like many vulnerable species, the dugong’s biggest threat is habitat loss.

Dugongs are vital to maintaining a healthy coastal ecosystem. When dugong populations are abundant, they naturally maintain seagrass and algae growth. This in turn balances the conditions of the water, prevents coastal erosion, and provides habitats for other creatures, establishing a balanced ecosystem. Pollution, coastal development, and industrial activities have led to the degradation of seagrass meadows. With the loss of these seagrass meadows, dugongs do not mate and reproduce normally, drastically lessening their numbers.

Dr. Christophe Cleguer and Dr. Amanda Hodgson from the Murdoch University’s Harry Butler Institute in Western Australia have been working with a team of international researchers to study dugongs and their habitats. Using drones, they plan to help conservation efforts for dugongs, scientifically known as sirenians. The first part of the drone project was to develop a system that could identify specific marine megafauna, herbivores. With the help of Dr. Frederic Maire from the Queensland University of Technology, Dr. Hodgson created a machine learning program that can identify dugongs from images collected by a drone with an 80% accuracy.

The next phase was to check if the drones could be used to better collect data than traditional methods that include observations from a boat and data collected by an airplane. Using a boat to observe dugongs as they graze is not ideal. The areas are often too shallow, and a boat could damage the fragile meadows. Filming from a plane is very expensive. Researchers need to hire trained pilots and are limited to the number of missions that can be conducted. However, as Dr. Cleguer pointed out, it is easy enough for one of the research team members to become a licensed drone operator.

For Dr. Cleguer and Dr. Hodgson, all they had to do was launch the drone from a designated spot. In this case, it was from a boat anchored offshore in the waters of Pilbara. The drone was then flown in a grid pattern. All of the images were uploaded to the computer system to analyze against existing databases. Throughout the trial, the team conducted 240 drone flights. The team averaged covering 12 square kilometers a day with the drone, documenting 149 dugongs.

The trial was a huge success. It proved that drones are far more cost and time efficient than traditional data collection methods. The computer learning program proved to accurately analyze data in record time too. Dr. Hodgson extolled the benefits of using drones to survey marine megafauna and their habitats. “It actually allows us to get fine scale information about where the dugongs are,” she said. “Being able to repeat surveys at different times of the day, different tides and seasonally provides us with a lot more detailed information than we could get in the past with one survey.”

Though drones have been popular for gathering scientific data for some time now, in the marine field there have been some setbacks. Mainly government regulations and the limited flight times available on a drone’s battery. But, as regulations have eased and technology progressed, teams like the one led by Dr. Cleguer have overcome these obstacles. “This a major step forward in the spatial modeling of animal density distribution,” he said. “These advances are an exciting development for wildlife managers who so often rely on spatially-explicit outputs to support effective management actions.” With the drone data, Dr. Cleguer and Dr. Hodgson will be able to help develop models to protect seagrass meadows from degradation and encourage the conservation of dugongs.

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