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“Use of unmanned aerial vehicles (UAVs) for mark-resight nesting population estimation of adult female green sea turtles at Raine Island”

https://doi.org/10.1371/journal.pone.0228524

Andrew Dunstan, Katharine Robertson, Richard Fitzpatrick, Jeffrey Pickford, Justin Meager

Turtle research using UAV drone technology

 

In a world-first, researchers at Raine Island, the world’s largest green turtle rookery have used a drone to conduct population surveys with stunning results.

Drone vision captured in December as part of the Raine Island Recovery Project showed up to 64,000 green turtles around the island, waiting to come ashore and lay clutches of eggs.

Dr Andrew Dunstan from the Department of Environment and Science (DES) and lead author of the paper said researchers had been investigating different methods to conduct turtle population surveys.

“New scientific research published in PLOS ONE found that drones, or Unmanned Aerial Vehicles (UAVs), are the most efficient survey method,” Dr Dunstan said.

“Underwater video using a G-Pro may also be a useful alternative for in-water surveys of turtles.

“Previous population survey methods involved painting a white stripe down the green turtle’s carapace when they were nesting on the beach, then getting on a small boat and counting painted and non-painted turtles.

“Our eyes are attracted much more to a turtle with a bright white stripe than an unpainted turtle, but the paint washed off after a few days and the counting accuracy suffered.

“Trying to accurately count thousands of painted and unpainted turtles from a small boat in rough weather was difficult. Using a drone is easier, safer, much more accurate and the data is permanently stored.”

 

 

 

 

 

 

The drone vision was analysed, frame by frame in the laboratory, reducing observer error and allowing accurate counts on painted and unpainted turtles.

“The ratio of unpainted and painted turtles allowed us to estimate the total population for last December to be 64,000 green turtles waiting to nest on the island,” Dr Dunstan said.

Research partner Richard Fitzpatrick from the Biopixel Oceans Foundation said vessel-based counts were inaccurate.

“When we compared drone counts to observer counts we found that we had under-estimated the numbers in the past by a factor 1.73,” Mr Fitzpatrick said.

“By using drones we have adjusted historical data. What previously took a number of researchers a long time can now be accomplished by one drone operator in minutes.”

 

Great Barrier Reef Foundation Managing Director Anna Marsden congratulated the researchers on their outstanding work, which was published for the first time on World Environment Day.

“This research combines science and technology to more effectively count endangered green turtles and is an important part of our broader Raine Island Recovery Project,” Ms Marsden said.

“Raine Island is the world’s largest green turtle nesting site and that’s why we’re working to protect and restore the island’s critical habitat.

“With our Raine Island Recovery Project partners, we are re-profiling the beach and building fences to strengthen the island’s resilience to ensure the survival of our northern green turtles and many other species.”

 

 

Dr Dunstan said the Raine Island Recovery Project is making a major contribution to the future sustainability of the world’s most important green turtle rookery.

“This research is of prime importance to the understanding and management of the vulnerable green turtle population,” he said.

“In the future, we will be able to automate these counts from video footage using artificial intelligence to allow the computer to do the counting for us.”

 

 

The five-year, $7.95 million Raine Island Recovery Project is a partnership between BHP, the Queensland Government, the Great Barrier Reef Marine Park Authority, and the Wuthathi and Meriam Nation (Ugar, Mer, Erub) and Traditional Owners, to protect and restore the island’s critical habitat to ensure the future of key marine species.

 

 

*All procedures used in this project were approved by the Raine Island Scientific Advisory Group and by the Queensland Department of Agriculture and Forestry Animal Ethics Committee (Permits SA 2015/12/533 and SA 2018/11/660).

The research paper can be found here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0228524

For more information on the Raine Island Recovery Project, please visit: https://parks.des.qld.gov.au/raineisland/